Assessment of microalloying effects on the high temperature fatigue behavior of NiAl

NASA Technical Reports Server (NTRS)

Noebe, R. D.; Lerch, B. A.; Rao, K. B. S.

1995-01-01

Binary NiAl suffers from a lack of strength and poor creep properties at and above 1000 K. Poor creep resistance in turn affects low cycle fatigue (LCF) lives at low strain ranges due to the additional interactions of creep damage. One approach for improving these properties involved microalloying with either Zr or N. As an integral part of a much larger alloying program the low cycle fatigue behavior of Zr and N doped nickel aluminides produced by extrusion of prealloyed powders has been investigated. Strain controlled LCF tests were performed in air at 1000 K. The influence of these microalloying additions on the fatigue life and cyclic stress response of polycrystalline NiAl are discussed.

Low cycle fatigue and creep fatigue interaction behavior of 9Cr-0.5Mo-1.8W-V-Nb heat-resistant steel at high temperature

NASA Astrophysics Data System (ADS)

Wang, Xiaowei; Zhang, Wei; Gong, Jianming; Wahab, Magd Abdel

2018-07-01

In this paper, Low Cycle Fatigue (LCF) and Creep-Fatigue Interaction (CFI) behavior of 9Cr-0.5Mo-1.8 W-V-Nb heat-resistant steel (ASME Grade P92 steel) at elevated temperature of 600 °C are investigated. Strain controlled LCF tests are conducted in fully reversed triangular waveform at different strain amplitudes ranging from 0.2% to 0.8%. CFI tests are conducted at 0.4% strain amplitude in trapezoid waveform with tensile hold time varying from 1 min to 60 min and compressive hold time varying from 1 min to 10 min. During LCF and CFI loadings, the evolution of cyclic stress, mean stress and stress relaxation behavior are investigated. It turns out that the softening behavior and lifetime degradation are dependent on strain amplitude, hold time and hold direction. In addition, the microstructure evolution and fracture behavior are characterized by optical, scanning and transmission electron microscope. The initial rapid softening behavior is attributed to the quick elimination of low angle boundaries, whereas no obvious microstructure alteration appears in the stable stage. Fracture behavior analysis reveals creep voids in long-term CFI tests facilitates the initiation and propagation of secondary cracks. The different responses of outer surface oxidation layer during cycling provides an explanation for severer damage of compressive hold and also accounts for the observed various fracture behavior of failed samples.

Cumulative fatigue damage behavior of MAR M-247

NASA Technical Reports Server (NTRS)

Mcgaw, Michael A.; Halford, Gary R.; Kalluri, Sreeramesh

1991-01-01

The objective was to examine the room temperature fatigue and nonlinear cumulative fatigue damage behavior of the cast nickel-based superalloy, MAR M-247. The fatigue test matrix consisted of single-level, fully reversed fatigue experiments. Two series of tests were performed: one of the two baseline fatigue LCF (Low-Cycle Fatigue) life levels was used in the first loading block, and the HCF (High-Cycle Fatigue) baseline loading level was used in the second block in each series. For each series, duplicate tests were performed at each applied LCF life fraction.

Functional and hypoglycemic properties of nopal cladodes (O. ficus-indica) at different maturity stages using in vitro and in vivo tests.

PubMed

Nuñez-López, María A; Paredes-López, Octavio; Reynoso-Camacho, Rosalía

2013-11-20

Nopal (Opuntia ficus-indica) cladodes are recommended for their therapeutic properties; their maturity stage may affect their biological properties. Cladodes of three maturity stages, from the same crop and location, were dehydrated and evaluated for some of their physicochemical and nutritional characteristics and antidiabetic properties. The flours of small and medium cladodes (SCF and MCF, respectively) had higher contents of dietary fiber, water absorption, swelling, and viscosity compared to those of the large cladode flour (LCF). Streptozotocin-induced diabetic rats, treated with MCF and SCF (doses of 50 mg/kg body weight), showed reduction of postprandial blood glucose on 46.0 and 23.6%, respectively (p < 0.05), in relation to the control; and LCF had no significant effect. In vitro, glucose diffusion tests showed similar ranking by the two former samples, whereas the latter was close to the control. Cladode maturity stages showed different fiber content and produced suspensions with differences in viscosity, which may affect in vitro and in vivo glucose responses.

Fatigue testing of a NiTi rotary instrument. Part 1: Strain-life relationship.

PubMed

Cheung, G S P; Darvell, B W

2007-08-01

To examine the fatigue behaviour using a strain-life approach, and to determine the effect of water on the fatigue life of a NiTi rotary instrument. Instruments of one brand of NiTi engine-file (size 25, ProFile 0.04 and 0.06) were subjected to rotational bending either in air or under water, the number of revolutions to fracture (N(f)) being recorded using an optical counter and an electronic break-detection circuit. The effective surface strain amplitude (epsilon(a)) for each specimen was determined from the curvature of the instrument (on a photograph) and the diameter of the fracture cross-section (from a scanning electron micrograph of the fracture surface). Strain was plotted against fatigue life and the low-cycle fatigue (LCF) region identified. Values were examined using two-way analysis of variance for difference between various instrument-environment combinations. A total of 212 instruments were tested. A strain-life relationship typical of metals was found. N(f) declined with an inverse power function dependence on epsilon(a). A fatigue limit was present at about 0.7% strain. The apparent fatigue-ductility exponent, a material constant for the LCF life of metals, was found to be between -0.45 and -0.55. There was a significant effect of the environmental condition on the LCF life, water being more detrimental than air. The fatigue behaviour of NiTi rotary instrument is typical of most metals, provided that the analysis is based on the surface strain amplitude, and showed a high-cycle and a LCF region. The LCF life is adversely affected by water.

Dynamic strain aging behavior of modified 9Cr-1Mo and reduced activation ferritic martensitic steels under low cycle fatigue

NASA Astrophysics Data System (ADS)

Mariappan, K.; Shankar, Vani; Sandhya, R.; Prasad Reddy, G. V.; Mathew, M. D.

2013-04-01

Influence of temperature and strain rate on low cycle fatigue (LCF) behavior of modified 9Cr-1Mo ferritic martensitic steel and 1.4W-0.06Ta reduced activation ferritic martensitic (RAFM) steel in normalized and tempered conditions was studied. Total strain controlled LCF tests between 300 and 873 K on modified 9Cr-1Mo steel and RAFM steel and at various strain rates on modified 9Cr-1Mo steel were performed at total strain amplitude of ±0.6%. Both the steels showed continuous cyclic softening at all temperatures. Whereas manifestations of dynamic strain aging (DSA) were observed in both the steels which decreased fatigue life at intermediate temperatures, at higher temperatures, oxidation played a crucial role in decreasing fatigue life.

Study on Dynamic Strain Aging and Low-Cycle Fatigue of Stainless Steel in Ultra-Supercritical Unit

NASA Astrophysics Data System (ADS)

Hongwei, Zhou; Yizhu, He; Jizu, Lv; Sixian, Rao

Dynamic strain aging (DSA) and low-cycle fatigue (LCF) behavior of TP347H stainless steel in ultra-supercritical unit were investigated at 550-650 °C. All the LCF tests were carried out under a fully-reversed, total axial strain control mode at the total strain amplitude from ±0.2% to ±1.0%. The effects of DSA in cyclic stress response, microstructure evolution and fatigue fracture surfaces and fatigue life were investigated in detail. The results show that DSA occurs during tensile, which is manifested as serrated flow in tensile stress-strain curves. The apparent activation energy for appearing of serrations in tensile stress-strain curves was 270 kJ/mol. Pipe diffusion of substitutional solutes such as Cr and Nb along the dislocation core, and strong interactions between segregated solutes and dislocations are considered as the mechanism of DSA. DSA partly restricts dislocation cross-slip, and dislocation cross-slip and planar-slip happen simultaneously during LCF. A lot of planar structures form, which is due to dislocation gliding on the special plane. This localized deformation structures result in many crack initiation sites. Meanwhile, DSA hardening increases cyclic stress response, accelerating crack propagation, which reduces high temperature strain fatigue life of steel.

Cloud overlapping parameter obtained from CloudSat/CALIPSO dataset and its application in AGCM with McICA scheme

NASA Astrophysics Data System (ADS)

Jing, Xianwen; Zhang, Hua; Peng, Jie; Li, Jiangnan; Barker, Howard W.

2016-03-01

Vertical decorrelation length (Lcf) as used to determine overlap of cloudy layers in GCMs was obtained from CloudSat/CALIPSO measurements, made between 2007 and 2010, and analyzed in terms of monthly means. Global distributions of Lcf were produced for several cross-sectional lengths. Results show that: Lcf over the tropical convective regions typically exceeds 2 km and shift meridionally with season; the smallest Lcf (< 1 km) tends to occur in regions dominated by marine stratiform clouds; Lcf for mid-to-high latitude continents of the Northern Hemisphere (NH) ranges from 5-6 km during winter to 2-3 km during summer; and there are marked differences between continental and oceanic values of Lcf in the mid-latitudes of the NH. These monthly-gridded, observationally-based values of Lcf data were then used by the Monte Carlo Independent Column Approximation (McICA) radiation routines within the Beijing Climate Center's GCM (BCC_AGCM2.0.1). Additionally, the GCM was run with two other descriptions of Lcf: one varied with latitude only, and the other was simply 2 km everywhere all the time. It is shown that using the observationally-based Lcf in the GCM led to local and seasonal changes in total cloud fraction and shortwave (longwave) cloud radiative effects that serve mostly to reduce model biases. This indicates that usage of Lcf that vary according to location and time has the potential to improve climate simulations.

Nickel speciation in several serpentine (ultramafic) topsoils via bulk synchrotron-based techniques

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

Siebecker, Matthew G.; Chaney, Rufus L.; Sparks, Donald L.

2017-07-01

Serpentine soils have elevated concentrations of trace metals including nickel, cobalt, and chromium compared to non-serpentine soils. Identifying the nickel bearing minerals allows for prediction of potential mobility of nickel. Synchrotron-based techniques can identify the solid-phase chemical forms of nickel with minimal sample treatment. Element concentrations are known to vary among soil particle sizes in serpentine soils. Sonication is a useful method to physically disperse sand, silt and clay particles in soils. Synchrotron-based techniques and sonication were employed to identify nickel species in discrete particle size fractions in several serpentine (ultramafic) topsoils to better understand solid-phase nickel geochemistry. Nickel commonlymore » resided in primary serpentine parent material such as layered-phyllosilicate and chain-inosilicate minerals and was associated with iron oxides. In the clay fractions, nickel was associated with iron oxides and primary serpentine minerals, such as lizardite. Linear combination fitting (LCF) was used to characterize nickel species. Total metal concentration did not correlate with nickel speciation and is not an indicator of the major nickel species in the soil. Differences in soil texture were related to different nickel speciation for several particle size fractionated samples. A discussion on LCF illustrates the importance of choosing standards based not only on statistical methods such as Target Transformation but also on sample mineralogy and particle size. Results from the F-test (Hamilton test), which is an underutilized tool in the literature for LCF in soils, highlight its usefulness to determine the appropriate number of standards to for LCF. EXAFS shell fitting illustrates that destructive interference commonly found for light and heavy elements in layered double hydroxides and in phyllosilicates also can occur in inosilicate minerals, causing similar structural features and leading to false positive results in LCF.« less

Effect of environment on low-cycle fatigue of a nickel-titanium instrument.

PubMed

Cheung, Gary S P; Shen, Ya; Darvell, Brian W

2007-12-01

This study examined the low-cycle fatigue (LCF) behavior of a nickel-titanium (NiTi) engine-file under various environmental conditions. One brand of NiTi instrument was subjected to rotational-bending fatigue in air, deionized water, sodium hypochlorite, or silicone oil. The curvature of each instrument, diameter of the fracture cross-section, and the number of rotations to failure were determined. The strain-life relationship in the LCF region was examined by using one-way analysis of variance, and the number of crack origins with chi2, for differences between groups. The results showed a linear relationship, on logarithmic scales, between the LCF life and the surface strain amplitude; regression line slopes were significantly different between noncorrosive (air, silicone oil) and corrosive (water, hypochlorite) environments (P < .05), as well as number of crack origins (P < .05). Hypochlorite was more detrimental to fatigue life than water. In conclusion, environmental conditions significantly affect the LCF behavior of NiTi rotary instruments. Fatigue testing of NiTi engine-files should be in a service-like environment.

Effects of Hot Rolling on Low-Cycle Fatigue Properties of Zn-22 wt.% Al Alloy at Room Temperature

NASA Astrophysics Data System (ADS)

Dong, X. H.; Cao, Q. D.; Ma, S. J.; Han, S. H.; Tang, W.; Zhang, X. P.

2016-09-01

The effects of the reduction ratio (RR) on the low-cycle fatigue (LCF) properties of the Zn-22 wt.% Al (Zn-22Al) alloy were investigated. Various grain sizes from 0.68 to 1.13 μm were obtained by controlled RRs. Tensile and LCF tests were carried out at room temperature. Superplasticity and cyclic softening were observed. Strength and ductility of the rolled Zn-22Al alloy increased with the RR, owing to the decrease in its grain size. The RR did not affect the cyclic softening behavior of the alloy. The fatigue life of the alloy decreased with increasing strain amplitude, while the fatigue life first decreased and then increased with increasing RR. The longest fatigue life was observed for the alloy rolled at a RR of 60%. A bilinear Coffin-Manson relationship was observed to hold true for this alloy.

Failure Mechanisms and Damage Model of Ductile Cast Iron Under Low-Cycle Fatigue Conditions

NASA Astrophysics Data System (ADS)

Wu, Xijia; Quan, Guangchun; MacNeil, Ryan; Zhang, Zhong; Sloss, Clayton

2014-10-01

Strain-controlled low-cycle fatigue (LCF) tests were conducted on ductile cast iron (DCI) at strain rates of 0.02, 0.002, and 0.0002/s in the temperature range from room temperature to 1073 K (800 °C). A constitutive-damage model was developed within the integrated creep-fatigue theory (ICFT) framework on the premise of strain decomposition into rate-independent plasticity and time-dependent creep. Four major damage mechanisms: (i) plasticity-induced fatigue, (ii) intergranular embrittlement (IE), (iii) creep, and (iv) oxidation were considered in a nonlinear creep-fatigue interaction model which represents the overall damage accumulation process consisting of oxidation-assisted fatigue crack nucleation and propagation in coalescence with internally distributed damage ( e.g., IE and creep), leading to final fracture. The model was found to agree with the experimental observations of the complex DCI-LCF phenomena, for which the linear damage summation rule would fail.

Orientation and temperature dependence of some mechanical properties of the single-crystal nickel-base superalloy Rene N4. II - Low cycle fatigue behavior

NASA Technical Reports Server (NTRS)

Gabb, T. P.; Gayda, J.; Miner, R. V.

1986-01-01

The low cycle fatigue (LCF) properties of a single-crystal nickel-base superalloy Rene N4, have been examined at 760 and 980 C in air. Specimens having crystallographic orientations near the 001, 011, -111, 023, -236, and -145 lines were tested in fully reversed, total-strain-controlled LCF tests at a frequency of 0.1 Hz. At 760 C, this alloy exhibited orientation dependent tension-compression anisotropies of yielding which continued to failure. Also at 760 C, orientations exhibiting predominately single slip exhibited serrated yielding for many cycles. At 980 C, orientation dependencies of yielding behavior were smaller. In spite of the tension-compression anisotropies, cyclic stress range-strain range behavior was not strongly orientation dependent for either test temperature. Fatigue life on a total strain range basis was highly orientation dependent at 760 and 980 C and was related chiefly to elastic modulus, low modulus orientations having longer lives. Stage I crack growth on 111 planes was dominant at 760 C, while Stage II crack growth occurred at 980 C. Crack initiation generally occurred at near-surface micropores, but occasionally at oxidation spikes in the 980 C tests.

Stress-strain time-dependent behavior of A356.0 aluminum alloy subjected to cyclic thermal and mechanical loadings

NASA Astrophysics Data System (ADS)

Farrahi, G. H.; Ghodrati, M.; Azadi, M.; Rezvani Rad, M.

2014-08-01

This article presents the cyclic behavior of the A356.0 aluminum alloy under low-cycle fatigue (or isothermal) and thermo-mechanical fatigue loadings. Since the thermo-mechanical fatigue (TMF) test is time consuming and has high costs in comparison to low-cycle fatigue (LCF) tests, the purpose of this research is to use LCF test results to predict the TMF behavior of the material. A time-independent model, considering the combined nonlinear isotropic/kinematic hardening law, was used to predict the TMF behavior of the material. Material constants of this model were calibrated based on room-temperature and high-temperature low-cycle fatigue tests. The nonlinear isotropic/kinematic hardening law could accurately estimate the stress-strain hysteresis loop for the LCF condition; however, for the out-of-phase TMF, the condition could not predict properly the stress value due to the strain rate effect. Therefore, a two-layer visco-plastic model and also the Johnson-Cook law were applied to improve the estimation of the stress-strain hysteresis loop. Related finite element results based on the two-layer visco-plastic model demonstrated a good agreement with experimental TMF data of the A356.0 alloy.

Fatigue and fracture mechanical behavior for Chinese A508-3 steel at room temperature

NASA Astrophysics Data System (ADS)

Shi, K. K.; Xie, H.; Zheng, B.; Fu, X. L.

2018-06-01

Material, A508-3 steel, has been used in nuclear reactor vessels. In the present study, fatigue and fracture mechanical behavior of Chinese A5083 steel at room temperature are studied by mechanical material testing machine (MTS). Test data of material’s mechanical behavior including uniaxial tension, low cycle fatigue (LCF), threshold value of stress intensity factor (SIF) range, fatigue crack growth (FCG), and fracture toughness is generated and given for further study. It is worth noting that the model in predicting FCG of material from LCF parameters is verified and discussed.

Influence of Localized Plasticity on IASCC Sensitivity of Austenitic Stainless Steels under PWR Primary Water

NASA Astrophysics Data System (ADS)

Cissé, Sarata; Tanguy, Benoit; Laffont, Lydia; Lafont, Marie-Christine; Guerre, Catherine; Andrieu, Eric

The sensibility of precipitation-strengthened A286 austenitic stainless steel to Stress Corrosion Cracking (SCC) is studied by means of Slow Strain Rate Tests (SSRT). First, alloy cold working by Low Cycle Fatigue (LCF) is investigated. Fatigue tests under plastic strain control are performed at different strain levels (Δ ɛp/2=0.2%, 0.5% and 0.8%) in order to establish correlation between stress softening and deformation microstructure resulting from LCF tests. Deformed microstructures have been identified through TEM investigations. Three states of cyclic behaviour for precipitation-strengthened A286 have been identified: hardening, cyclic softening and finally saturation of softening. It is shown that the A286 alloy cyclic softening is due to microstructural features such as defects — free deformation bands resulting from dislocations motion along family plans <111>, that swept defects or γ' precipitates and lead to deformation localization. In order to quantify effects of plastic localized deformation on intergranular stress corrosion cracking (IGSCC) of the A286 alloy in PWR primary water, slow strain rate tests are conducted. For each cycling conditions, two specimens at a similar stress level are tested: the first containing free precipitate deformation bands, the other not significant of a localized deformation state. SSRT tests are still in progress.

Local Context Finder (LCF) reveals multidimensional relationships among mRNA expression profiles of Arabidopsis responding to pathogen infection

PubMed Central

Katagiri, Fumiaki; Glazebrook, Jane

2003-01-01

A major task in computational analysis of mRNA expression profiles is definition of relationships among profiles on the basis of similarities among them. This is generally achieved by pattern recognition in the distribution of data points representing each profile in a high-dimensional space. Some drawbacks of commonly used pattern recognition algorithms stem from their use of a globally linear space and/or limited degrees of freedom. A pattern recognition method called Local Context Finder (LCF) is described here. LCF uses nonlinear dimensionality reduction for pattern recognition. Then it builds a network of profiles based on the nonlinear dimensionality reduction results. LCF was used to analyze mRNA expression profiles of the plant host Arabidopsis interacting with the bacterial pathogen Pseudomonas syringae. In one case, LCF revealed two dimensions essential to explain the effects of the NahG transgene and the ndr1 mutation on resistant and susceptible responses. In another case, plant mutants deficient in responses to pathogen infection were classified on the basis of LCF analysis of their profiles. The classification by LCF was consistent with the results of biological characterization of the mutants. Thus, LCF is a powerful method for extracting information from expression profile data. PMID:12960373

Experimental and numerical investigation of strain rate effect on low cycle fatigue behaviour of AA 5754 alloy

NASA Astrophysics Data System (ADS)

Kumar, P.; Singh, A.

2018-04-01

The present study deals with evaluation of low cycle fatigue (LCF) behavior of aluminum alloy 5754 (AA 5754) at different strain rates. This alloy has magnesium (Mg) as main alloying element (Al-Mg alloy) which makes this alloy suitable for Marines and Cryogenics applications. The testing procedure and specimen preparation are guided by ASTM E606 standard. The tests are performed at 0.5% strain amplitude with three different strain rates i.e. 0.5×10-3 sec-1, 1×10-3 sec-1 and 2×10-3 sec-1 thus the frequency of tests vary accordingly. The experimental results show that there is significant decrease in the fatigue life with the increase in strain rate. LCF behavior of AA 5754 is also simulated at different strain rates by finite element method. Chaboche kinematic hardening cyclic plasticity model is used for simulating the hardening behavior of the material. Axisymmetric finite element model is created to reduce the computational cost of the simulation. The material coefficients used for “Chaboche Model” are determined by experimentally obtained stabilized hysteresis loop. The results obtained from finite element simulation are compared with those obtained through LCF experiments.

Predictive Engineering Tools for Injection-Molded Long-Carbon-Fiber Thermoplastic Composites. Topical Report

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

Nguyen, Ba Nghiep; Fifield, Leonard S.; Wang, Jin

2016-06-01

This project aimed to integrate, optimize, and validate the fiber orientation and length distribution models previously developed and implemented in the Autodesk® Simulation Moldflow® Insight (ASMI) software package for injection-molded long-carbon-fiber (LCF) thermoplastic composite structures. The project was organized into two phases. Phase 1 demonstrated the ability of the advanced ASMI package to predict fiber orientation and length distributions in LCF/polypropylene (PP) and LCF/polyamide-6, 6 (PA66) plaques within 15% of experimental results. Phase 2 validated the advanced ASMI package by predicting fiber orientation and length distributions within 15% of experimental results for a complex three-dimensional (3D) Toyota automotive part injection-moldedmore » from LCF/PP and LCF/PA66 materials. Work under Phase 2 also included estimate of weight savings and cost impacts for a vehicle system using ASMI and structural analyses of the complex part. The present report summarizes the completion of Phases 1 and 2 work activities and accomplishments achieved by the team comprising Pacific Northwest National Laboratory (PNNL); Purdue University (Purdue); Virginia Polytechnic Institute and State University (Virginia Tech); Autodesk, Inc. (Autodesk); PlastiComp, Inc. (PlastiComp); Toyota Research Institute North America (Toyota); Magna Exteriors and Interiors Corp. (Magna); and University of Illinois. Figure 1 illustrates the technical approach adopted in this project that progressed from compounding LCF/PP and LCF/PA66 materials, to process model improvement and implementation, to molding and modeling LCF/PP and LCF/PA66 plaques. The lessons learned from the plaque study and the successful validation of improved process models for fiber orientation and length distributions for these plaques enabled the project to go to Phase 2 to mold, model, and optimize the 3D complex part.« less

Influence of subsolvus thermomechanical processing on the low-cycle fatigue properties of haynes 230 alloy

NASA Astrophysics Data System (ADS)

Vecchio, Kenneth S.; Fitzpatrick, Michael D.; Klarstrom, Dwaine

1995-03-01

Strain-controlled low-cycle fatigue tests have been conducted in air at elevated temperature to determine the influence of subsolvus thermomechanical processing on the low-cycle fatigue (LCF) behavior of HAYNES 230 alloy. A series of tests at various strain ranges was conducted on material experimentally processed at 1121 °C, which is below the M23C6 carbide solvus temperature, and on material fully solution annealed at 1232 °C. A comparative strain-life analysis was performed on the LCF results, and the cyclic hardening/softening characteristics were examined. At 760 °C and 871 °C, the fatigue life of the experimental 230/1121 material was improved relative to the standard 230/1232 material up to a factor of 3. The fatigue life advantage of the experimental material was related primarily to a lower plastic (inelastic) strain amplitude response for a given imposed total strain range. It appears the increase in monotonic flow stress exhibited by the finer grain size experimental material has been translated into an increase in cyclic flow stress at the 760 °C and 871 °C test temperatures. Both materials exhibited entirely transgranular fatigue crack initiation and propagation modes at these temperatures. The LCF performance of the experimental material in tests performed at 982 °C was improved relative to the standard material up to a factor as high as 2. The life advantage of the 230/1121 material occurred despite having a larger plastic strain amplitude than the standard 230/1232 material for a given total strain range. Though not fully understood at present, it is suspected that this behavior is related to the deleterious influence of grain boundaries in the fatigue crack initiations of the standard processed material relative to the experimental material, and ultimately to differences in carbide morphology as a result of thermomechanical processing.

Mechanical Behavior of Advanced Materials for Aerospace Applications

NASA Technical Reports Server (NTRS)

Telesman, Ignancy (Technical Monitor); Kantzos, Peter; Shannon, Brian

2003-01-01

The purpose of this study was to determine whether High Cycle Fatigue (HCF) loading has any deleterious synergistic effect on life when combined with the typical Low Cycle Fatigue (LCF) loading present in engine disks. This interaction is particularly important in the rim region of blisk applications, where fatigue initiations from vibratory stresses (HCF) may be propagated to the disk by LCF. The primary effort in this study was focused on determining and documenting initiation sites and damage mechanisms. Under LCF loading conditions the failures were predominantly surface initiated, while HCF loading favored internal initiations. Deleterious HCF/LCF interactions would always result in a transition from internal to surface initiations. The results indicated that under the relative stress conditions evaluated there was no interaction between HCF and LCF. In FY99 this effort was extended to investigate several other loading conditions (R-ratio effects) as well as interactions between LCF and two-hour tensile dwells. The results will be published as a NASA Technical Memorandum.

Increased Mechanical Properties Through the Addition of Zr to GRCop-84

NASA Technical Reports Server (NTRS)

Ellis, David L.; Lerch, Bradley A.

2011-01-01

GRCop-84 (Cu-8 at.% Cr-4 at.% Nb) has shown exceptional mechanical properties above 932 F (773 K). However, its properties below 932 F (773 K) are inferior to precipitation strengthened alloys such as Cu-Cr, Cu-Zr and Cu-Cr-Zr when they are in the fully aged, hard-drawn condition. It has been noted that the addition of small amounts of Zr, typically 0.1 wt.% to 0.5 wt.%, can greatly enhance the mechanical properties of copper-based alloys. Limited testing was conducted upon GRCop-84 with an addition of 0.4 wt.% Zr to determine its tensile, creep and low cycle fatigue (LCF) properties. Very large increases in strength (up to 68%) and ductility (up to 123%) were observed at both room temperature and 932 F (773 K). Creep properties at 932 F (773 K) demonstrated more than an order of magnitude decrease in the creep rate relative to unmodified GRCop-84 with a corresponding order of magnitude increase in creep life. Limited LCF testing showed that the modified alloy had a comparable LCF life at room temperature, but it was capable of sustaining a much higher load. While more testing and composition optimization are required, the addition of Zr to GRCop-84 has shown clear benefits to mechanical properties.

Effect of Creep and Oxidation on Reduced Creep-Fatigue life of Ni-based Alloy 617 at 850 C

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

Chen, Xiang; Yang, Zhiqing; Sokolov, Mikhail A

Low cycle fatigue (LCF) and creep fatigue testing of Ni-based alloy 617 was carried out at 850 C. Compared with its LCF life, the material s creep fatigue life decreases to different extents depending on test conditions. To elucidate the microstructure-fatigue property relationship for alloy 617 and the effect of creep and oxidation on its fatigue life, systematic microstructural investigations were carried out using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and electron backscatter diffraction (EBSD). In LCF tests, as the total strain range increased, deformations concentrated near high angle grain boundaries (HAGBs). The strain hold period in the creep fatiguemore » tests introduced additional creep damage to the material, which revealed the detrimental effect of the strain hold time on the material fatigue life in two ways. First, the strain hold time enhanced the localized deformation near HAGBs, resulting in the promotion of intergranular cracking of alloy 617. Second, the strain hold time encouraged grain boundary sliding, which resulted in interior intergranular cracking of the material. Oxidation accelerated the initiation of intergranular cracking in alloy 617. In the crack propagation stage, if oxidation was promoted and the cyclic oxidation damage was greater than the fatigue damage, oxidation-assisted intergranular crack growth resulted in a significant reduction in the material s fatigue life.« less

Family food purchases of high- and low-calorie foods in full-service supermarkets and other food retailers by Black women in an urban US setting.

PubMed

Chrisinger, Benjamin W; DiSantis, Katherine Isselmann; Hillier, Amy E; Kumanyika, Shiriki K

2018-06-01

Public health interventions to increase supermarket access assume that shopping in supermarkets is associated with healthier food purchases compared to other store types. To test this assumption, we compared purchasing patterns by store-type for certain higher-calorie, less healthy foods (HCF) and lower-calorie, healthier foods (LCF) in a sample of 35 black women household shoppers in Philadelphia, PA. Data analyzed were from 450 food shopping receipts collected by these shoppers over four-week periods in 2012. We compared the likelihood of purchasing the HCF (sugar-sweetened beverages, sweet/salty snacks, and grain-based snacks) and LCF (low-fat dairy, fruits, and vegetables) at full-service supermarkets and six other types of food retailers, using generalized estimating equations. Thirty-seven percent of participants had household incomes at or below the poverty line, and 54% had a BMI >30. Participants shopped primarily at full-service supermarkets (55%) or discount/limited assortment supermarkets (22%), making an average of 11 shopping trips over a 4-week period and spending mean (SD) of $350 ($222). Of full-service supermarket receipts, 64% included at least one HCF item and 58% at least one LCF. Most trips including HCF (58%) and LCF (60%) expenditures were to full-service or discount/limited assortment supermarkets rather than smaller stores. Spending a greater percent of total dollars in full-service supermarkets was associated with spending more on HCF (p = 0.03) but not LCF items (p = 0.26). These findings in black women suggest a need for more attention to supermarket interventions that change retailing practices and/or consumer shopping behaviors related to foods in the HCF categories examined.

The J-2X Fuel Turbopump - Turbine Nozzle Low Cycle Fatigue Acceptance Rationale

NASA Technical Reports Server (NTRS)

Hawkins, Lakiesha V.; Duke, Gregory C.; Newman, Wesley R.; Reynolds, David C.

2011-01-01

The J-2X Fuel Turbopump (FTP) turbine, which drives the pump that feeds hydrogen to the J-2X engine for main combustion, is based on the J-2S design developed in the early 1970 s. Updated materials and manufacturing processes have been incorporated to meet current requirements. This paper addresses an analytical concern that the J-2X Fuel Turbine Nozzle Low Cycle Fatigue (LCF) analysis did not meet safety factor requirements per program structural assessment criteria. High strains in the nozzle airfoil during engine transients were predicted to be caused by thermally induced stresses between the vane hub, vane shroud, and airfoil. The heritage J-2 nozzle was of a similar design and experienced cracks in the same area where analysis predicted cracks in the J-2X design. Redesign options that did not significantly impact the overall turbine configuration were unsuccessful. An approach using component tests and displacement controlled fracture mechanics analysis to evaluate LCF crack initiation and growth rate was developed. The results of this testing and analysis were used to define the level of inspection on development engine test units. The programmatic impact of developing crack initiation/growth rate/arrest data was significant for the J-2X program. Final Design Certification Review acceptance logic will ultimately be developed utilizing this test and analytical data.

The Effect of Boron on the Low Cycle Fatigue Behavior of Disk Alloy KM4

NASA Technical Reports Server (NTRS)

Gabb, Timothy; Gayda, John; Sweeney, Joseph

2000-01-01

The durability of powder metallurgy nickel base superalloys employed as compressor and turbine disks is often limited by low cycle fatigue (LCF) crack initiation and crack growth from highly stressed surface locations (corners, holes, etc.). Crack growth induced by dwells at high stresses during aerospace engine operation can be particularly severe. Supersolvus solution heat treatments can be used to produce coarse grain sizes approaching ASTM 6 for improved resistance to dwell fatigue crack growth. However, the coarse grain sizes reduce yield strength, which can lower LCF initiation life. These high temperature heat treatments also can encourage pores to form. In the advanced General Electric disk superalloy KM4, such pores can initiate fatigue cracks that limit LCF initiation life. Hot isostatic pressing (HIP) during the supersolvus solution heat treatment has been shown to improve LCF initiation life in KM4, as the HIP pressure minimizes formation of the pores. Reduction of boron levels in KM4 has also been shown to increase LCF initiation life after a conventional supersolvus heat treatment, again possibly due to effects on the formation tendencies of these pores. However, the effects of reduced boron levels on microstructure, pore characteristics, and LCF failure modes in KM4 still need to be fully quantified. The objective of this study was to determine the effect of boron level on the microstructure, porosity, LCF behavior, and failure modes of supersolvus heat treated KM4.

Effects of δ phase and cold drawing ratio on the LCF properties of alloy 718 wire

NASA Astrophysics Data System (ADS)

Jeong, Yong-Kwon; Jo, Chang-Yong; Kim, In-Bae

2000-10-01

The effects of the amount and distribution of δ particles on the low cycle fatigue (LCF) properties of alloy 718 wire were investigated. The amount and distribution of δ particles were controlled by cold drawing followed by a variety of agings. As the cold drawing ratio and aging time at 1116K increased, the well developed granular δ particles increased in amount and their distribution at grain/twin boundaries became more uniform. Regardless of the aging conditions, the LCF life increased as the cold drawing ratio increased. The granular particles precipitated along the grain boundary also improved the LCF life of alloy 718 wire since they inhibited crack propagation. After Merrick heat treatment, 50% of the cold drawn wire displayed lower 698K tensile and yield strength than 30% of the cold drawn wire. This was because the higher strain induced by the cold drawing prior to the first aging at 1116K appeared to promote the precipitation of the δ phase during aging, which has no influence on the strength of the material but has same stoichiometry with the γ phase as Ni3Nb and, as a result, the higher strain precipitated a smaller quantity of γ particles with subsequent aging, which is a major hardening phase of the alloy. Cold drawing also lowered the precipitation temperature of the δ phase.

Controlling nitrogen migration through micro-nano networks

NASA Astrophysics Data System (ADS)

Cai, Dongqing; Wu, Zhengyan; Jiang, Jiang; Wu, Yuejin; Feng, Huiyun; Brown, Ian G.; Chu, Paul K.; Yu, Zengliang

2014-01-01

Nitrogen fertilizer unabsorbed by crops eventually discharges into the environment through runoff, leaching and volatilization, resulting in three-dimensional (3D) pollution spanning from underground into space. Here we describe an approach for controlling nitrogen loss, developed using loss control fertilizer (LCF) prepared by adding modified natural nanoclay (attapulgite) to traditional fertilizer. In the aqueous phase, LCF self-assembles to form 3D micro/nano networks via hydrogen bonds and other weak interactions, obtaining a higher nitrogen spatial scale so that it is retained by a soil filtering layer. Thus nitrogen loss is reduced and sufficient nutrition for crops is supplied, while the pollution risk of the fertilizer is substantially lowered. As such, self-fabrication of nano-material was used to manipulate the nitrogen spatial scale, which provides a novel and promising approach for the research and control of the migration of other micro-scaled pollutants in environmental medium.

Controlling nitrogen migration through micro-nano networks.

PubMed

Cai, Dongqing; Wu, Zhengyan; Jiang, Jiang; Wu, Yuejin; Feng, Huiyun; Brown, Ian G; Chu, Paul K; Yu, Zengliang

2014-01-14

Nitrogen fertilizer unabsorbed by crops eventually discharges into the environment through runoff, leaching and volatilization, resulting in three-dimensional (3D) pollution spanning from underground into space. Here we describe an approach for controlling nitrogen loss, developed using loss control fertilizer (LCF) prepared by adding modified natural nanoclay (attapulgite) to traditional fertilizer. In the aqueous phase, LCF self-assembles to form 3D micro/nano networks via hydrogen bonds and other weak interactions, obtaining a higher nitrogen spatial scale so that it is retained by a soil filtering layer. Thus nitrogen loss is reduced and sufficient nutrition for crops is supplied, while the pollution risk of the fertilizer is substantially lowered. As such, self-fabrication of nano-material was used to manipulate the nitrogen spatial scale, which provides a novel and promising approach for the research and control of the migration of other micro-scaled pollutants in environmental medium.

Controlling nitrogen migration through micro-nano networks

PubMed Central

Cai, Dongqing; Wu, Zhengyan; Jiang, Jiang; Wu, Yuejin; Feng, Huiyun; Brown, Ian G.; Chu, Paul K.; Yu, Zengliang

2014-01-01

Nitrogen fertilizer unabsorbed by crops eventually discharges into the environment through runoff, leaching and volatilization, resulting in three-dimensional (3D) pollution spanning from underground into space. Here we describe an approach for controlling nitrogen loss, developed using loss control fertilizer (LCF) prepared by adding modified natural nanoclay (attapulgite) to traditional fertilizer. In the aqueous phase, LCF self-assembles to form 3D micro/nano networks via hydrogen bonds and other weak interactions, obtaining a higher nitrogen spatial scale so that it is retained by a soil filtering layer. Thus nitrogen loss is reduced and sufficient nutrition for crops is supplied, while the pollution risk of the fertilizer is substantially lowered. As such, self-fabrication of nano-material was used to manipulate the nitrogen spatial scale, which provides a novel and promising approach for the research and control of the migration of other micro-scaled pollutants in environmental medium. PMID:24419037

Constant pH Accelerated Molecular Dynamics Investigation of the pH Regulation Mechanism of Dinoflagellate Luciferase.

PubMed

Donnan, Patrick H; Ngo, Phong D; Mansoorabadi, Steven O

2018-01-23

The bioluminescence reaction in dinoflagellates involves the oxidation of an open-chain tetrapyrrole by the enzyme dinoflagellate luciferase (LCF). The activity of LCF is tightly regulated by pH, where the enzyme is essentially inactive at pH ∼8 and optimally active at pH ∼6. Little is known about the mechanism of LCF or the structure of the active form of the enzyme, although it has been proposed that several intramolecularly conserved histidine residues in the N-terminal region are important for the pH regulation mechanism. Here, constant pH accelerated molecular dynamics was employed to gain insight into the conformational activation of LCF induced by acidification.

Summary of Coating Surveys on the Four Air Command Frigates (Zeven Provincien Class) (Onderzoek naar de conditie van de coatingsystemen op vier luchtcommandofregatten (Zeven Provincien Klasse))

DTIC Science & Technology

2008-03-26

of these inspections have been drafted into the following extensive reports for each frigate: * TQS-RAP-07-855/ gge of March 30, 2007 for Hr.Ms...34Evertsen" (LCF 4) * TQS-RAP-07-856/ gge of March 30, 2007 for Hr.Ms. "Tromp" (LCF 2) • TQS-RAP-07-857/ gge of March 30, 2007 for Hr.Ms. "De Ruyter" (LCF 3...34 TQS-RAP-08-3316/ gge of January 10, 2008 for Hr.Ms. -Zeven Provincien" (LCF 1) Each report consists of a description of results and all protocols made

Predictive Engineering Tools for Injection-Molded Long-Carbon-Fiber Thermoplastic Composites - FY 2014 Fourth Quarterly Report

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

Nguyen, Ba Nghiep; Fifield, Leonard S.; Mathur, Raj N.

2014-09-30

During the last quarter of FY 2014, the following technical progress has been made toward project milestones: 1) Autodesk, Inc. (Autodesk) has implemented a new fiber length distribution (FLD) model based on an unbreakable length assumption with Reduced Order Modeling (ROM) by the Proper Orthogonal Decomposition (POD) approach in the mid-plane, dual-domain and 3D solvers. 2) Autodesk improved the ASMI 3D solver for fiber orientation prediction using the anisotropic rotary diffusion (ARD) – reduced strain closure (RSC) model. 3) Autodesk received consultant services from Prof. C.L. Tucker at the University of Illinois on numerical simulation of fiber orientation and fibermore » length. 4) PlastiComp, Inc. (PlastiComp) suggested to Purdue University a procedure for fiber separation using an inert-gas atmosphere in the burn-off furnace. 5) Purdue University (Purdue) hosted a face-to-face project review meeting at Purdue University on August 6-7, 2014. 6) Purdue conducted fiber orientation measurements for 3 PlastiComp plaques: fast-fill 30wt% LCF/PP edged-gated, slow-fill 50wt% LCF/PP edge-gated, and slow-fill 50wt% LCF/PP center-gated plaques, and delivered the orientation data for these plaques at the selected locations (named A, B, and C) to PNNL. 7) PNNL conducted ASMI mid-plane analyses for the above PlastiComp plaques and compared the predicted fiber orientations with the measured data provided by Purdue at Locations A, B, and C on these plaques. 8) PNNL planned the project review meeting (August 6-7, 2014) with Purdue. 9) PNNL performed ASMI analyses for the Toyota complex parts with and without ribs, having different wall thicknesses, and using the PlastiComp 50wt% LCF/PP, 50wt% LCF/PA66, 30wt% LCF/PP, and 30wt% LCF/PA66 materials to provide guidance for tool design and modifications needed for molding these parts. 10) Magna Exteriors and Interiors Corp. (Magna) molded plaques from the 50% LCF/PP and 50% LCF/PA66 materials received from Plasticomp in order to extract machine purgings (purge materials) from Magna’s 200-Ton Injection Molding machine targeted to mold the complex part. 11) Toyota and Magna discussed with PNNL tool modification for molding the complex part.« less

Mechanism of substrate recognition by the novel Botulinum Neurotoxin subtype F5.

PubMed

Guo, Jiubiao; Chan, Edward Wai Chi; Chen, Sheng

2016-01-22

Botulinum Neurotoxins (BoNTs) are the causative agents of botulism, which act by potently inhibiting the neurotransmitter release in motor neurons. Seven serotypes of BoNTs designated as BoNT/A-G have been identified. Recently, two novel types of Botulinum neurotoxins, which cleave a novel scissile bond, L(54)-E(55), of VAMP-2 have been reported including BoNT/F subtype F5 and serotype H. However, little has been known on how these BoNTs recognize their substrates. The present study addressed for the first time the unique substrate recognition mechanism of LC/F5. Our data indicated that the optimal peptide required for efficient LC/F5 substrate cleavage is VAMP-2 (20-65). Interestingly, the overall mode of substrate recognition adopted by LC/F5 was similar to LC/F1, except that its recognition sites were shifted one helix toward the N-terminus of VAMP-2 when compared to that of LC/F1. The composition of LC/F5 pockets were found to have changed accordingly to facilitate specific recognition of these new sites of VAMP-2, including the P2', P1', P2, P3, B3, B2 and B1 sites. The study provides direct evidence of the evolutionary adaption of BoNT to recognize its substrate which is useful for effective antitoxin and inhibitor development.

Cosmological Constraints from Fourier Phase Statistics

NASA Astrophysics Data System (ADS)

Ali, Kamran; Obreschkow, Danail; Howlett, Cullan; Bonvin, Camille; Llinares, Claudio; Oliveira Franco, Felipe; Power, Chris

2018-06-01

Most statistical inference from cosmic large-scale structure relies on two-point statistics, i.e. on the galaxy-galaxy correlation function (2PCF) or the power spectrum. These statistics capture the full information encoded in the Fourier amplitudes of the galaxy density field but do not describe the Fourier phases of the field. Here, we quantify the information contained in the line correlation function (LCF), a three-point Fourier phase correlation function. Using cosmological simulations, we estimate the Fisher information (at redshift z = 0) of the 2PCF, LCF and their combination, regarding the cosmological parameters of the standard ΛCDM model, as well as a Warm Dark Matter (WDM) model and the f(R) and Symmetron modified gravity models. The galaxy bias is accounted for at the level of a linear bias. The relative information of the 2PCF and the LCF depends on the survey volume, sampling density (shot noise) and the bias uncertainty. For a volume of 1h^{-3}Gpc^3, sampled with points of mean density \\bar{n} = 2× 10^{-3} h3 Mpc^{-3} and a bias uncertainty of 13%, the LCF improves the parameter constraints by about 20% in the ΛCDM cosmology and potentially even more in alternative models. Finally, since a linear bias only affects the Fourier amplitudes (2PCF), but not the phases (LCF), the combination of the 2PCF and the LCF can be used to break the degeneracy between the linear bias and σ8, present in 2-point statistics.

An investigation on high temperature fatigue properties of tempered nuclear-grade deposited weld metals

NASA Astrophysics Data System (ADS)

Cao, X. Y.; Zhu, P.; Yong, Q.; Liu, T. G.; Lu, Y. H.; Zhao, J. C.; Jiang, Y.; Shoji, T.

2018-02-01

Effect of tempering on low cycle fatigue (LCF) behaviors of nuclear-grade deposited weld metal was investigated, and The LCF tests were performed at 350 °C with strain amplitudes ranging from 0.2% to 0.6%. The results showed that at a low strain amplitude, deposited weld metal tempered for 1 h had a high fatigue resistance due to high yield strength, while at a high strain amplitude, the one tempered for 24 h had a superior fatigue resistance due to high ductility. Deposited weld metal tempered for 1 h exhibited cyclic hardening at the tested strain amplitudes. Deposited weld metal tempered for 24 h exhibited cyclic hardening at a low strain amplitude but cyclic softening at a high strain amplitude. Existence and decomposition of martensite-austenite (M-A) islands as well as dislocations activities contributed to fatigue property discrepancy among the two tempered deposited weld metal.

Forecasting Low-Cycle Fatigue Performance of Twinning-Induced Plasticity Steels: Difficulty and Attempt

NASA Astrophysics Data System (ADS)

Shao, C. W.; Zhang, P.; Zhang, Z. J.; Liu, R.; Zhang, Z. F.

2017-12-01

We find the existing empirical relations based on monotonic tensile properties and/or hardness cannot satisfactorily predict the low-cycle fatigue (LCF) performance of materials, especially for twinning-induced plasticity (TWIP) steels. Given this, we first identified the different deformation mechanisms under monotonic and cyclic deformation after a comprehensive study of stress-strain behaviors and microstructure evolutions for Fe-Mn-C alloys during tension and LCF, respectively. It is found that the good tensile properties of TWIP steel mainly originate from the large activation of multiple twinning systems, which may be attributed to the grain rotation during tensile deformation; while its LCF performance depends more on the dislocation slip mode, in addition to its strength and plasticity. Based on this, we further investigate the essential relations between microscopic damage mechanism (dislocation-dislocation interaction) and cyclic stress response, and propose a hysteresis loop model based on dislocation annihilation theory, trying to quickly assess the LCF resistance of Fe-Mn-C steels as well as other engineering materials. It is suggested that the hysteresis loop and its evolution can provide significant information on cyclic deformation behavior, e.g., (point) defect multiplication and vacancy aggregation, which may help estimate the LCF properties.

A Combined High and Low Cycle Fatigue Model for Life Prediction of Turbine Blades

PubMed Central

Yue, Peng; Yu, Zheng-Yong; Wang, Qingyuan

2017-01-01

Combined high and low cycle fatigue (CCF) generally induces the failure of aircraft gas turbine attachments. Based on the aero-engine load spectrum, accurate assessment of fatigue damage due to the interaction of high cycle fatigue (HCF) resulting from high frequency vibrations and low cycle fatigue (LCF) from ground-air-ground engine cycles is of critical importance for ensuring structural integrity of engine components, like turbine blades. In this paper, the influence of combined damage accumulation on the expected CCF life are investigated for turbine blades. The CCF behavior of a turbine blade is usually studied by testing with four load-controlled parameters, including high cycle stress amplitude and frequency, and low cycle stress amplitude and frequency. According to this, a new damage accumulation model is proposed based on Miner’s rule to consider the coupled damage due to HCF-LCF interaction by introducing the four load parameters. Five experimental datasets of turbine blade alloys and turbine blades were introduced for model validation and comparison between the proposed Miner, Manson-Halford, and Trufyakov-Kovalchuk models. Results show that the proposed model provides more accurate predictions than others with lower mean and standard deviation values of model prediction errors. PMID:28773064

A Combined High and Low Cycle Fatigue Model for Life Prediction of Turbine Blades.

PubMed

Zhu, Shun-Peng; Yue, Peng; Yu, Zheng-Yong; Wang, Qingyuan

2017-06-26

Combined high and low cycle fatigue (CCF) generally induces the failure of aircraft gas turbine attachments. Based on the aero-engine load spectrum, accurate assessment of fatigue damage due to the interaction of high cycle fatigue (HCF) resulting from high frequency vibrations and low cycle fatigue (LCF) from ground-air-ground engine cycles is of critical importance for ensuring structural integrity of engine components, like turbine blades. In this paper, the influence of combined damage accumulation on the expected CCF life are investigated for turbine blades. The CCF behavior of a turbine blade is usually studied by testing with four load-controlled parameters, including high cycle stress amplitude and frequency, and low cycle stress amplitude and frequency. According to this, a new damage accumulation model is proposed based on Miner's rule to consider the coupled damage due to HCF-LCF interaction by introducing the four load parameters. Five experimental datasets of turbine blade alloys and turbine blades were introduced for model validation and comparison between the proposed Miner, Manson-Halford, and Trufyakov-Kovalchuk models. Results show that the proposed model provides more accurate predictions than others with lower mean and standard deviation values of model prediction errors.

Advanced oxide dispersion strengthened sheet alloys for improved combustor durability

NASA Technical Reports Server (NTRS)

Henricks, R. J.

1981-01-01

Burner design modifications that will take advantage of the improved creep and cyclic oxidation resistance of oxide dispersion strengthened (ODS) alloys while accommodating the reduced fatigue properties of these materials were evaluated based on preliminary analysis and life predictions, on construction and repair feasibility, and on maintenance and direct operating costs. Two designs - the film cooled, segmented louver and the transpiration cooled, segmented twin Wall - were selected for low cycle fatigue (LCF) component testing. Detailed thermal and structural analysis of these designs established the strain range and temprature at critical locations resulting in predicted lives of 10,000 cycles for MA 956 alloy. The ODs alloys, MA 956 and HDA 8077, demonstrated a 167 C (300 F) temperature advantage over Hastelloy X alloy in creep strength and oxidation resistance. The MA 956 alloy was selected for mechanical property and component test evaluations. The MA 956 alloy was superior to Hastelloy X in LCF component testing of the film cooled, segmented louver design.

Molecular cloning and identification of a flavanone 3-hydroxylase gene from Lycium chinense, and its overexpression enhances drought stress in tobacco.

PubMed

Song, Xinyu; Diao, Jinjin; Ji, Jing; Wang, Gang; Guan, Chunfeng; Jin, Chao; Wang, Yurong

2016-01-01

Flavonoids, as plant secondary metabolites, are widespread throughout the plant kingdom and involved in many physiological and biochemical processes. Drought resistance is attributed to flavonoids with respect to protective functions in the cell wall and membranes. The flavanone 3-hydroxylase (F3H) gene which encodes flavanone 3-hydroxylase, is essential in flavonoids biosynthetic pathway. Lycium chinense (L. chinense) is a deciduous woody perennial halophyte that grows under a large variety of environmental conditions and survives under extreme drought stress. A novel cDNA sequence coding a F3H gene in Lycium chinense (LcF3H, GenBank: KJ636468.1) was isolated. The open reading frame of LcF3H comprised 1101 bp encoding a polypeptide of 366 amino acids with a molecular weight of about 42 kDa and an isoelectric point of 5.32. The deduced LcF3H protein showed high identities with other plant F3Hs, and the conserved motifs were found in LcF3H at similar positions like other F3Hs. The recombinant protein converted naringen into dihydrokaempferol in vitro. Since studies have shown that amongst flavonoids, flavan-3-ols (catechin and epicatechin) have direct free radical scavenging activity to maintain the normal physiological function of cells in vivo, these data support the possible relationship between the oxidative damage and the regulation of LcF3H gene expression in L. chinense under drought stress. In order to better understand the biotechnological potential of LcF3H, gene overexpression was conducted in tobacco. The content of flavan-3-ols and the tolerance to drought stress were increased in LcF3H overexpressing tobacco. Analysis of transgenic tobacco lines also showed that antioxidant enzyme activities were increased meanwhile the malondialdehyde (MDA) content and the content of H2O2 were reduced comparing to nontransformed tobacco plants. Furthermore, the photosynthesis rate was less decreased in the transgenetic plants. These results suggest that LcF3H plays a role in enhancing drought tolerance in L. chinense, and its overexpression increases tolerance to drought stress by improving the antioxidant system in tobacco. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Predictive Engineering Tools for Injection-Molded Long-Carbon-Fiber Thermoplastic Composites - Second FY 2015 Quarterly Report

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

Nguyen, Ba Nghiep; Fifield, Leonard S.; Kijewski, Seth A.

During the second quarter of FY 2015, the following technical progress has been made toward project milestones: 1) Autodesk reviewed 3D fiber orientation distribution (FOD) comparisons and provided support on improving accuracy. 2) Autodesk reviewed fiber length distribution (FLD) data comparisons and provided suggestions, assisted PNNL in FOD and FLD parameter settings optimization, and advised PNNL on appropriate through thickness thermal conductivity for improved frozen layer effect on FOD predictions. Autodesk also participated in project review meetings including preparations and discussions towards passing the go/no-go decision point. 3) Autodesk implemented an improved FOD inlet profile specification method through the partmore » thickness for 3D meshes and provided an updated ASMI research version to PNNL. 4) The University of Illinois (Prof. C.L. Tucker) provided Autodesk with ideas to improve fiber orientation modeling 5) Purdue University re-measured fiber orientation for the fast-fill 50wt% LCF/PA66 edge-gated plaque, and delivered the fiber orientation data for this plaque at the selected locations (named A, B, and C, Figure 1) to PNNL. Purdue also re-measured fiber orientation for locations A on the fast-fill 30wt% LCF/PP and 50wt% LCF/PA66 center-gated plaques, which exhibited anomalous fiber orientation behavior. 6) Purdue University conducted fiber length measurements and delivered the length data to PNNL for the purge materials (slow-fill 30wt% LCF/PP and 30wt% LCF/PA66 purge materials) and PlastiComp plaques selected on the go/no-go list for fiber length model validation (i.e., slow-fill edge-gated 30wt% LCF/PP and 30wt% LCF/PA66 plaques, Locations A, B, and C). 7) PNNL developed a method to recover intact carbon fibers from LCF/PA66 materials. Isolated fibers were shipped to Purdue for length distribution analysis. 8) PNNL completed ASMI mid-plane analyses for all the PlastiComp plaques defined on the go/no-go list for fiber orientation (FO) model validation and compared the predicted fiber orientations with the measured data provided by Purdue at Locations A, B, and C on these plaques. The 15% accuracy criterion based on evaluation of tensile and bending stiffness was used to assess the accuracy in fiber orientation predictions. 9) PNNL completed ASMI mid-plane analyses for all the PlastiComp plaques defined on the go/no-go list for fiber length distribution (FLD) model validation and compared the predicted length distributions with the measured data provided by Purdue at Locations A, B, and C on these plaques. The 15% accuracy criterion based on evaluation of tensile and bending stiffness was used to assess the accuracy in fiber orientation predictions. 10) PNNL tested the new ASMI version received from Autodesk in March 2015, examined and discussed 3D fiber orientation predictions for PlastiComp plaques. 11) PlastiComp, Inc. (PlastiComp), Toyota Research Institute North America (Toyota) and Magna Exteriors and Interiors Corporation (Magna) participated in discussions with team members on the go/no-go plan. Toyota continued the discussion with Magna on tool modification for molding the complex part in order to achieve the target fiber length in the part.« less

Research in mathematical theory of computation. [computer programming applications

NASA Technical Reports Server (NTRS)

Mccarthy, J.

1973-01-01

Research progress in the following areas is reviewed: (1) new version of computer program LCF (logic for computable functions) including a facility to search for proofs automatically; (2) the description of the language PASCAL in terms of both LCF and in first order logic; (3) discussion of LISP semantics in LCF and attempt to prove the correctness of the London compilers in a formal way; (4) design of both special purpose and domain independent proving procedures specifically program correctness in mind; (5) design of languages for describing such proof procedures; and (6) the embedding of ideas in the first order checker.

High and low contact frequency cardiac rehabilitation programmes elicit similar improvements in cardiorespiratory fitness and cardiovascular risk factors.

PubMed

LaHaye, Stephen A; Lacombe, Shawn P; Koppikar, Sahil; Lun, Grace; Parsons, Trisha L; Hopkins-Rosseel, Diana

2014-12-01

Cardiac rehabilitation (CR) is a proven intervention that substantially improves physical health and decreases death and disability following a cardiovascular event. Traditional CR typically involves 36 on-site exercise sessions spanning a 12-week period. To date, the optimal dose of CR has yet to be determined. This study compared a high contact frequency CR programme (HCF, 34 on-site sessions) with a low contact frequency CR programme (LCF, eight on-site sessions) of equal duration (4 months). A total of 961 low-risk cardiac patients (RARE score <4) self-selected either a HCF (n = 469) or LCF (n = 492) CR programme. Cardiorespiratory fitness and cardiovascular risk factors were measured on admission and discharge. Similar proportions of patients completed HCF (n = 346) and LCF (n = 351) (p = 0.398). Patients who were less fit (<8 METs) were more likely to drop out of the LCF group, while younger patients (<60 years) were more likely to drop out of the HCF group. Both groups experienced similar reductions in weight (-2.3 vs. -2.4 kg; p = 0.779) and improvements in cardiorespiratory fitness (+1.5 vs. +1.4 METs; p = 0.418). Patients in the LCF programme achieved equivalent results to those in the HCF programme. Certain subgroups of patients, however, may benefit from participation in a HCF programme, including those patients who are predisposed to prematurely discontinuing the programme and those patients who would benefit from increased monitoring. The LCF model can be employed as an alternative option to widen access and participation for patients who are unable to attend HCF programmes due to distance or time limitations. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Experimental study of microstructure changes due to low cycle fatigue of a steel nanocrystallised by Surface Mechanical Attrition Treatment (SMAT)

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

Sun, Z.

Electron Backscatter Diffraction technique is used to characterize the microstructure of 316L steel generated by Surface Mechanical Attrition Treatment (SMAT) before and after low cycle fatigue tests. A grain size gradient is generated from the top surface to the interior of the samples after SMAT so that three main regions can be distinguished below the treated surface: (i) the ultra-fine grain area within 5 μm under the top surface with preferably oriented grains, (ii) the intermediate area where the original grains are partially transformed, and (iii) the edge periphery area where the original grains are just mechanically deformed with themore » presence of plastic slips. Fatigue tests show that cyclic loading does not change the grain orientation spread and does not activate any plastic slip in the ultra-fine grain top surface area induced by SMAT. On the opposite, in the plastically SMAT affected region including the intermediate area and the edge periphery area, new slip systems are activated by low cycle fatigue while the grain orientation spread is increased. These results represent a first very interesting step towards the characterization and understanding of mechanical mechanisms involved during the fatigue of a grain size gradient material. - Highlights: •LCF tests are carried out on specimens processed by SMAT. •EBSD is used to investigate microstructural changes induced by LCF. •A grain size gradient is generated by SMAT from surface to the bulk of the fatigue samples. •New slip systems are activated by LCF and GOS is increased in plastically deformed region. •However, these phenomena are not observed in the top surface ultra-fine grain area.« less

An assessment of cold work effects on strain-controlled low-cycle fatigue behavior of type 304 stainless steel

NASA Astrophysics Data System (ADS)

Rao, K. Bhanu Sankara; Valsan, M.; Sandhya, R.; Mannan, S. L.; Rodriguez, P.

1993-04-01

The influence of prior cold work (PCW) on low-cycle fatigue (LCF) behavior of type 304 stainless steel has been studied at 300, 823, 923, and 1023 K by conducting total axial strain-controlled tests in solution annealed (SA, 0 pct PCW) condition and on specimens having three levels of PCW, namely, 10, 20, and 30 pct. A triangular waveform with a constant frequency of 0.1 Hz was employed for all of the tests performed over strain amplitudes in the range of ±0.25 to ± 1.25 pct. These studies have revealed that fatigue life is strongly dependent on PCW, temperature, and strain amplitude employed in testing. The SA material generally displayed better endurance in terms of total and plastic strain amplitudes than the material in 10, 20, and 30 pct PCW conditions at all of the temperatures. However, at 300 K at very low strain amplitudes, PCW material exhibited better total strain fatigue resistance. At 823 K, LCF life decreased with increasing PCW, whereas at 923 K, 10 pct PCW displayed the lowest life. An improvement in life occurred for prior deformations exceeding 10 pct at all strain amplitudes at 923 K. Fatigue life showed a noticeable decrease with increasing temperature up to 1023 K in PCW state. On the other hand, SA material displayed a minimum in fatigue life at 923 K. The fatigue life results of SA as well as all of the PCW conditions obeyed the Basquin and Coffin-Manson relationships at 300, 823, and 923 K. The constants and exponents in these equations were found to depend on the test temperature and prior metallurgical state of the material. A study is made of cyclic stress-strain behavior in SA and PCW states and the relationship between the cyclic strain-hardening exponent and fatigue behavior at different temperatures has been explored. The influence of environment on fatigue crack initiation and propagation behavior has been examined.

Porosity Assessment for Different Diameters of Coir Lignocellulosic Fibers

NASA Astrophysics Data System (ADS)

da Luz, Fernanda Santos; Paciornik, Sidnei; Monteiro, Sergio Neves; da Silva, Luiz Carlos; Tommasini, Flávio James; Candido, Verônica Scarpini

2017-10-01

The application of natural lignocellulosic fibers (LCFs) in engineering composites has increased interest in their properties and structural characteristics. In particular, the inherent porosity of an LCF markedly affects its density and the adhesion to polymer matrices. For the first time, both open and closed porosities of a natural LCF, for different diameter ranges, were assessed. Fibers extracted from the mesocarp of the coconut fruit were investigated by nondestructive methods of density measurements and x-ray microtomography (microCT). It was found that, for all diameter ranges, the closed porosity is significantly higher than the open porosity. The total porosity increases with diameter to around 60% for coir fibers with more than 503 μm in diameter. The amount and characteristics of these open and closed porosities were revealed by t test and Weibull statistics as well as by microCT.

78 FR 44052 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-23

... a regulatory distinction; and 4. Will not have a significant economic impact, positive or negative... events (LCF1) and partial low cycle fatigue events (LCF2) as those terms are defined in the... the full and partial low fatigue cycle events and record on the component card or equivalent record...

NASA/Navy lift/cruise fan. Phase 1: Design summary

NASA Technical Reports Server (NTRS)

1977-01-01

The initial design of the LCF459 lift/cruise fan system is documented. The LCF459 is a 1.5 meter diameter turbotip lift/cruise fan whose design point pressure ratio is 1.32 at a tip speed of 353 meters per second. The gas source for the tip turbine is the YJ97-GE-100 engine.

Iron doped LiCoPO4 thin films for lithium-ion microbatteries obtained by ns pulsed laser deposition

NASA Astrophysics Data System (ADS)

Smaldone, A.; Brutti, S.; De Bonis, A.; Ciarfaglia, N.; Santagata, A.; Teghil, R.

2018-07-01

Well crystallized and homogeneous iron doped LiCoPO4 (LCfP) thin films have been grown by ns Pulsed Laser Ablation, at ambient temperature without any substrate heating or post-annealing treatments. The films have been deposited in vacuum and in the presence of buffer gases (O2, Ar) and it has been found that their crystallinity, structure and morphology depend on pressure conditions. The films have been studied by Scanning Electron Microscopy and X Ray Diffraction, while their first steps of growth have been characterized by Transmission Electron Microscopy. A study of the plasma produced by the laser ablation in the different pressure conditions has been carried out with the aim of elucidate the mechanisms involved in the films deposition. LCfP thin films have been also tested as microelectrodes in lithium cells in galvanostatic condition for analyzing the reversibility of the lithium-ion battery.

Low-cycle fatigue of NiTi rotary instruments of various cross-sectional shapes.

PubMed

Cheung, G S P; Darvell, B W

2007-08-01

To compare the low-cycle fatigue (LCF) behaviour of some commercial NiTi instruments subjected to rotational bending, a deformation mode similar to an engine-file rotating in a curved root canal, using a strain-life analysis, in water. A total of 286 NiTi rotary instruments from four manufacturers were constrained into a curvature by three rigid, stainless steel pins whilst rotating at a rate of 250 rpm in deionized water until broken. The number of revolutions was recorded using an optical counter and an electronic break-detection circuit. The surface strain amplitude, calculated from the curvature (from a photograph) and diameter of the fracture cross-section (from a scanning electron micrograph), was plotted against the number of cycles to fracture for each instrument. A regression line was fitted to the LCF lives for each brand; the value was compared with that of others using one-way analysis of variance (ANOVA). The number of crack origins observed on the fractographic view was examined with chi-square for differences amongst various groups. A linear strain-life relationship, on logarithmic scales, was obtained for the LCF region with an apparent fatigue-ductility exponent ranging from -0.40 to -0.56. The number of crack-initiation sites, as observed on the fracture cross-section, differed between brands (chi(2), P < 0.05), but not LCF life (one-way ANOVA, P > 0.05). The LCF life of NiTi instruments declines with an inverse power function dependence on surface strain amplitude, but is not affected by the cross-sectional shape of the instrument.

78 FR 47235 - Airworthiness Directives; General Electric Company Turbofan Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-05

... revenue flight cycles. These parts were then installed into engines and introduced into revenue service... cycle counts of those LLPs to account for the additional low cycle fatigue (LCF) life consumed during... Boeing 747-8 flight tests had consumed more cyclic life than they would have in revenue flight cycles...

Probabilistic Analysis of Aircraft Gas Turbine Disk Life and Reliability

NASA Technical Reports Server (NTRS)

Melis, Matthew E.; Zaretsky, Erwin V.; August, Richard

1999-01-01

Two series of low cycle fatigue (LCF) test data for two groups of different aircraft gas turbine engine compressor disk geometries were reanalyzed and compared using Weibull statistics. Both groups of disks were manufactured from titanium (Ti-6Al-4V) alloy. A NASA Glenn Research Center developed probabilistic computer code Probable Cause was used to predict disk life and reliability. A material-life factor A was determined for titanium (Ti-6Al-4V) alloy based upon fatigue disk data and successfully applied to predict the life of the disks as a function of speed. A comparison was made with the currently used life prediction method based upon crack growth rate. Applying an endurance limit to the computer code did not significantly affect the predicted lives under engine operating conditions. Failure location prediction correlates with those experimentally observed in the LCF tests. A reasonable correlation was obtained between the predicted disk lives using the Probable Cause code and a modified crack growth method for life prediction. Both methods slightly overpredict life for one disk group and significantly under predict it for the other.

Natural Variation at sympathy for the ligule Controls Penetrance of the Semidominant Liguleless narrow-R Mutation in Zea mays

PubMed Central

Buescher, Elizabeth M.; Moon, Jihyun; Runkel, Anne; Hake, Sarah; Dilkes, Brian P.

2014-01-01

Leaf architecture determines plant structural integrity, light harvesting, and economic considerations such as plant density. Ligules, junctions at the leaf sheath and blade in grasses, protect stalks from environmental stresses and, in conjunction with auricles, controls leaf angle. Previous studies in mutants have recessive liguleless mutants (lg1 and lg2) and dominant mutations in knotted1-like homeobox genes (Lg3-O, Lg4, and Kn1) involved in ligule development. Recently, a new semidominant liguleless mutant, Liguleless narrow (Lgn-R), has been characterized in maize that affects ligule and auricle development and results in a narrow leaf phenotype. We show that quantitative genetic variation affects penetrance of Lgn-R. To examine the genetic architecture underlying Lgn-R expressivity, crosses between Lgn-R/+ mutants in a B73 background and intermated B73 x Mo17 recombinant inbred lines were evaluated in multiple years and locations. A single main-effect quantitative trait locus (QTL) on chromosome 1 (sympathy for the ligule; sol) was discovered with a Mo17-contributed allele that suppressed Lgn-R mutant phenotypes. This QTL has a genetic-interaction with a locus on chromosome 7 (lucifer; lcf) for which the B73-contributed allele increases the ability of the solMo17 allele to suppress Lgn-R. Neither of the genetic intervals likely to contain sol or lcf overlap with any current liguleless genes nor with previously identified genome-wide association QTL connected to leaf architecture. Analysis of phenotypes across environments further identified a genotype by enviroment interaction determining the strength of the sol x lcf interaction. PMID:25344411

Predictive Engineering Tools for Injection-Molded Long-Carbon-Fiber Thermoplastic Composites - Fourth FY 2015 Quarterly Report

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

Nguyen, Ba Nghiep; Fifield, Leonard S.; Wollan, Eric J.

2015-11-13

During the last quarter of FY 2015, the following technical progress has been made toward project milestones: 1) PlastiComp used the PlastiComp direct in-line (D-LFT) Pushtrusion system to injection mold 40 30wt% LCF/PP parts with ribs, 40 30wt% LCF/PP parts without ribs, 10 30wt% LCF/PA66 parts with ribs, and 35 30wt% LCF/PA66 parts without ribs. In addition, purge materials from the injection molding nozzle were obtained for fiber length analysis, and molding parameters were sent to PNNL for process modeling. 2) Magna cut samples at four selected locations (named A, B, C and D) from the non-ribbed Magna-molded parts basedmore » on a plan discussed with PNNL and the team and shipped these samples to Virginia Tech for fiber orientation and length measurements. 3) Virginia Tech started fiber orientation and length measurements for the samples taken from the complex parts using Virginia Tech’s established procedure. 4) PNNL and Autodesk built ASMI models for the complex parts with and without ribs, reviewed process datasheets and performed preliminary analyses of these complex parts using the actual molding parameters received from Magna and PlastiComp to compare predicted to experimental mold filling patterns. 5) Autodesk assisted PNNL in developing the workflow to use Moldflow fiber orientation and length results in ABAQUS® simulations. 6) Autodesk advised the team on the practicality and difficulty of material viscosity characterization from the D-LFT process. 7) PNNL developed a procedure to import fiber orientation and length results from a 3D ASMI analysis to a 3D ABAQUS® model for structural analyses of the complex part for later weight reduction study. 8) In discussion with PNNL and Magna, Toyota developed mechanical test setups and built fixtures for three-point bending and torsion tests of the complex parts. 9) Toyota built a finite element model for the complex parts subjected to torsion loading. 10) PNNL built the 3D ABAQUS® model of the complex ribbed part subjected to 3-point bending. 11) University of Illinois (Prof. C.L. Tucker) advised the team on fiber orientation and fiber length measurement options, modeling issues as well as interpretation of data.« less

Predictive Engineering Tools for Injection-Molded Long-Carbon-Fiber Thermoplastic Composites - FY 2016 First Quarterly Report

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

Nguyen, Ba Nghiep; Fifield, Leonard S.; Lambert, Gregory

During the first quarter of FY 2016, the following technical progress has been made toward project milestones: 1) Virginia Tech completed fiber orientation (FO) measurements for the samples taken at Locations A, B, C and D (Figure 1) from the 30wt% LCF/PP and 30wt% LCF/PA66 ribbed and non-ribbed complex parts using Virginia Tech’s established procedure. Virginia Tech delivered to PNNL all the measured fiber orientation data for validating ASMI fiber orientation predictions. 2)Virginia Tech performed fiber length distribution (FLD) measurements for the samples taken at Locations A, B, C and D from these complex parts using Virginia Tech’s established procedure.more » Virginia also re-assessed previous data and measured fiber length distributions in the corresponding nozzle purging materials and delivered to PNNL all the measured length data for validating ASMI fiber length predictions. 3)Based on measured fiber orientation data, Autodesk identified the parameters of the anisotropic rotary diffusion reduced strain closure (ARD-RSC) model [1] and provided PNNL with the values of these parameters that were used in ASMI analyses of the complex parts. 4) Magna provided Virginia Tech with additional samples cut out from the 30wt% LCF/PP and 30wt% LCF/PA66 ribbed parts (Figure 1) for fiber length and orientation measurements. 5) In discussion with Autodesk, PNNL performed 3D ASMI analyses of the 30wt% LCF/PP and 30wt% LCF/PA66 ribbed and non-ribbed complex parts to predict fiber orientations and length distributions in these parts. The issues observed through the analyses regarding fiber orientation distributions profiles and abnormal length distributions were reported to Autodesk. Autodesk is working to resolve these issues. 6) PNNL completed 3D ASMI analyses of the complex parts and compared predicted fiber orientation results at Locations A, B, and C on the non-ribbed parts, and at Locations A, B, C and D on the ribbed parts with the corresponding measured data. PNNL also evaluated the within-15%-agreement criterion using the principal tensile and flexural moduli computed based on predicted vs. measured fiber orientation results. 7) PNNL developed and discussed with Toyota, Magna and PlastiComp a method to perform weight and cost reduction for making the 30wt% LCF/PA66 ribbed part through comparative three-point bending simulations of this part and of similar parts in steel.« less

Investigation of Advanced Processed Single-Crystal Turbine Blade Alloys

NASA Technical Reports Server (NTRS)

Peters, B. J.; Biondo, C. M.; DeLuca, D. P.

1995-01-01

This investigation studied the influence of thermal processing and microstructure on the mechanical properties of the single-crystal, nickel-based superalloys PWA 1482 and PWA 1484. The objective of the program was to develop an improved single-crystal turbine blade alloy that is specifically tailored for use in hydrogen fueled rocket engine turbopumps. High-gradient casting, hot isostatic pressing (HIP), and alternate heat treatment (HT) processing parameters were developed to produce pore-free, eutectic-free microstructures with different (gamma)' precipitate morphologies. Test materials were cast in high thermal gradient solidification (greater than 30 C/cm (137 F/in.)) casting furnaces for reduced dendrite arm spacing, improved chemical homogeneity, and reduced interdendritic pore size. The HIP processing was conducted in 40 cm (15.7 in.) diameter production furnaces using a set of parameters selected from a trial matrix study. Metallography was conducted on test samples taken from each respective trial run to characterize the as-HIP microstructure. Post-HIP alternate HT processes were developed for each of the two alloys. The goal of the alternate HT processing was to fully solution the eutectic gamma/(gamma)' phase islands and to develop a series of modified (gamma)' morphologies for subsequent characterization testing. This was accomplished by slow cooling through the (gamma)' solvus at controlled rates to precipitate volume fractions of large (gamma)'. Post-solution alternate HT parameters were established for each alloy providing additional volume fractions of finer precipitates. Screening tests included tensile, high-cycle fatigue (HCF), smooth and notched low-cycle fatigue (LCF), creep, and fatigue crack growth evaluations performed in air and high pressure (34.5 MPa (5 ksi)) hydrogen at room and elevated temperature. Under the most severe embrittling conditions (HCF and smooth and notched LCF in 34.5 MPa (5 ksi) hydrogen at 20 C (68 F), screening test results showed increases in fatigue life typically on the order of 1OX, when compared to the current Space Shuttle Main Engine (SSME) Alternate Turbopump (AT) blade alloy (PWA 1480).

Influence of Thermal Aging on Tensile and Low Cycle Fatigue Behavior of Type 316LN Austenitic Stainless Steel Weld Joint

NASA Astrophysics Data System (ADS)

Suresh Kumar, T.; Nagesha, A.; Ganesh Kumar, J.; Parameswaran, P.; Sandhya, R.

2018-05-01

Influence of short-term thermal aging on the low-cycle fatigue (LCF) behavior of 316LN austenitic stainless steel weld joint with 0.07 wt pct N has been investigated. Prior thermal exposure was found to improve the fatigue life compared with the as-welded condition. Besides, the treatment also imparted a softening effect on the weld metal, leading to an increase in the ductility of the weld joint which had a bearing on the cyclic stress response. The degree of cyclic hardening was seen to increase after aging. Automated ball-indentation (ABI) technique was employed toward understanding the mechanical properties of individual zones across the weld joint. It was observed that the base metal takes most of the applied cyclic strain during LCF deformation in the as-welded condition. In the aged condition, however, the weld also participates in the cyclic deformation. The beneficial effect of thermal aging on cyclic life is attributed to a reduction in the severity of the metallurgical notch leading to a restoration of ductility of the weld region. The transformation of δ-ferrite to σ-phase during the aging treatment was found to influence the location of crack initiation. Fatigue cracks were found to initiate in the base metal region of the joint in most of the testing conditions. However, embrittlement in the weld metal caused a shift in the point of crack initiation with increasing strain amplitude under LCF.

Effects of Control Mode and R-Ratio on the Fatigue Behavior of a Metal Matrix Composite

NASA Technical Reports Server (NTRS)

2005-01-01

Composite Because of their high specific stiffness and strength at elevated temperatures, continuously reinforced metal matrix composites (MMC's) are under consideration for a future generation of aeropropulsion systems. Since components in aeropropulsion systems experience substantial cyclic thermal and mechanical loads, the fatigue behavior of MMC's is of great interest. Almost without exception, previous investigations of the fatigue behavior of MMC's have been conducted in a tension-tension, load-controlled mode. This has been due to the fact that available material is typically less than 2.5-mm thick and, therefore, unable to withstand high compressive loads without buckling. Since one possible use of MMC's is in aircraft skins, this type of testing mode may be appropriate. However, unlike aircraft skins, most engine components are thick. In addition, the transient thermal gradients experienced in an aircraft engine will impose tension-compression loading on engine components, requiring designers to understand how the MMC will behave under fully reversed loading conditions. The increased thickness of the MMC may also affect the fatigue life. Traditionally, low-cycle fatigue (LCF) tests on MMC's have been performed in load control. For monolithic alloys, low-cycle fatigue tests are more typically performed in strain control. Two reasons justify this choice: (1) the critical volume from which cracks initiate and grow is generally small and elastically constrained by the larger surrounding volume of material, and (2) load-controlled, low-cycle fatigue tests of monolithics invariably lead to unconstrained ratcheting and localized necking--an undesired material response because the failure mechanism is far more severe than, and unrelated to, the fatigue mechanism being studied. It is unknown if this is the proper approach to composite testing. However, there is a lack of strain-controlled data on which to base any decisions. Consequently, this study addresses the isothermal, LCF behavior of a [0]_32 MMC tested under strain- and load-controlled conditions for both zero-tension and tension-compression loading conditions. These tests were run at 427 C on thick specimens of SiC-reinforced Ti-15-3. For the fully-reversed tests, no difference was observed in the lives between the load- and strain-controlled tests. However, for the zero-tension tests, the strain-controlled tests had longer lives by a factor of 3 in comparison to the load-controlled tests. This was due to the fact that under strain-control the specimens cyclically softened, reducing the cracking potential. In contrast, the load-controlled tests ratcheted toward larger tensile strains leading to an eventual overload of the fibers. Fatigue tests revealed that specimens tested under fully-reversed conditions had lives approximately an order of magnitude longer than for those specimens tested under zero tension. When examined on a strain-range basis, the fully reversed specimens had similar, but still shorter lives than those of the unreinforced matrix material. However, the composite had a strain limitation at short lives because of the limited strain capacity of the brittle ceramic fiber. The composite also suffered at very high lives because of the lack of an apparent fatigue limit in comparison to the unreinforced matrix. The value of adding fibers to the matrix is apparent when the fatigue lives are plotted as a function of stress range. Here, the composite is far superior to the unreinforced matrix because of the additional load-carrying capacity of the fibers.

Buying Food on Sale: A Mixed Methods Study With Shoppers at an Urban Supermarket, Philadelphia, Pennsylvania, 2010–2012

PubMed Central

Kumanyika, Shiriki K.; Stites, Shana D.; Singletary, S. Brook; Cooblall, Clarissa; DiSantis, Katherine Isselmann

2014-01-01

Introduction The obesity epidemic has drawn attention to food marketing practices that may increase the likelihood of caloric overconsumption and weight gain. We explored the associations of discounted prices on supermarket purchases of selected high-calorie foods (HCF) and more healthful, low-calorie foods (LCF) by a demographic group at high risk of obesity. Methods Our mixed methods design used electronic supermarket purchase data from 82 low-income (primarily African American female) shoppers for households with children and qualitative data from focus groups with demographically similar shoppers. Results In analyses of 6,493 food purchase transactions over 65 weeks, the odds of buying foods on sale versus at full price were higher for grain-based snacks, sweet snacks, and sugar-sweetened beverages (odds ratios: 6.6, 5.9, and 2.6, respectively; all P < .001) but not for savory snacks. The odds of buying foods on sale versus full price were not higher for any of any of the LCF (P ≥ .07). Without controlling for quantities purchased, we found that spending increased as percentage saved from the full price increased for all HCF and for fruits and vegetables (P ≤ .002). Focus group participants emphasized the lure of sale items and took advantage of sales to stock up. Conclusion Strategies that shift supermarket sales promotions from price reductions for HCF to price reductions for LCF might help prevent obesity by decreasing purchases of HCF. PMID:25188276

Buying food on sale: a mixed methods study with shoppers at an urban supermarket, Philadelphia, Pennsylvania, 2010-2012.

PubMed

Phipps, Etienne J; Kumanyika, Shiriki K; Stites, Shana D; Singletary, S Brook; Cooblall, Clarissa; DiSantis, Katherine Isselmann

2014-09-04

The obesity epidemic has drawn attention to food marketing practices that may increase the likelihood of caloric overconsumption and weight gain. We explored the associations of discounted prices on supermarket purchases of selected high-calorie foods (HCF) and more healthful, low-calorie foods (LCF) by a demographic group at high risk of obesity. Our mixed methods design used electronic supermarket purchase data from 82 low-income (primarily African American female) shoppers for households with children and qualitative data from focus groups with demographically similar shoppers. In analyses of 6,493 food purchase transactions over 65 weeks, the odds of buying foods on sale versus at full price were higher for grain-based snacks, sweet snacks, and sugar-sweetened beverages (odds ratios: 6.6, 5.9, and 2.6, respectively; all P < .001) but not for savory snacks. The odds of buying foods on sale versus full price were not higher for any of any of the LCF (P ≥ .07). Without controlling for quantities purchased, we found that spending increased as percentage saved from the full price increased for all HCF and for fruits and vegetables (P ≤ .002). Focus group participants emphasized the lure of sale items and took advantage of sales to stock up. Strategies that shift supermarket sales promotions from price reductions for HCF to price reductions for LCF might help prevent obesity by decreasing purchases of HCF.

Strontium-free rare earth perovskite ferrites with fast oxygen exchange kinetics: Experiment and theory

NASA Astrophysics Data System (ADS)

Berger, Christian; Bucher, Edith; Windischbacher, Andreas; Boese, A. Daniel; Sitte, Werner

2018-03-01

The Sr-free mixed ionic electronic conducting perovskites La0.8Ca0.2FeO3-δ (LCF82) and Pr0.8Ca0.2FeO3-δ (PCF82) were synthesized via a glycine-nitrate process. Crystal structure, phase purity, and lattice constants were determined by XRD and Rietveld analysis. The oxygen exchange kinetics and the electronic conductivity were obtained from in-situ dc-conductivity relaxation experiments at 600-800 °C and 1×10-3≤pO2/bar≤0.1. Both LCF82 and PCF82 show exceptionally fast chemical surface exchange coefficients and chemical diffusion coefficients of oxygen. The oxygen nonstochiometry of LCF82 and PCF82 was determined by precision thermogravimetry. A point defect model was used to calculate the thermodynamic factors of oxygen and to estimate self-diffusion coefficients and ionic conductivities. Density Functional Theory (DFT) calculations on the crystal structure, oxygen vacancy formation as well as oxygen migration energies are in excellent agreement with the experimental values. Due to their favourable properties both LCF82 and PCF82 are of interest for applications in solid oxide fuel cell cathodes, solid oxide electrolyser cell anodes, oxygen separation membranes, catalysts, or electrochemical sensors.

Distribution of Inclusion-Initiated Fatigue Cracking in Powder Metallurgy Udimet 720 Characterized

NASA Technical Reports Server (NTRS)

Bonacuse, Peter J.; Kantzos, Pete T.; Barrie, Robert; Telesman, Jack; Ghosn, Louis J.; Gabb, Timothy P.

2004-01-01

In the absence of extrinsic surface damage, the fatigue life of metals is often dictated by the distribution of intrinsic defects. In powder metallurgy (PM) alloys, relatively large defects occur rarely enough that a typical characterization with a limited number of small volume fatigue test specimens will not adequately sample inclusion-initiated damage. Counterintuitively, inclusion-initiated failure has a greater impact on the distribution in PM alloy fatigue lives because they tend to have fewer defects than their cast and wrought counterparts. Although the relative paucity of defects in PM alloys leads to higher mean fatigue lives, the distribution in observed lives tends to be broader. In order to study this important failure initiation mechanism without expending an inordinate number of specimens, a study was undertaken at the NASA Glenn Research Center where known populations of artificial inclusions (seeds) were introduced to production powder. Fatigue specimens were machined from forgings produced from the seeded powder. Considerable effort has been expended in characterizing the crack growth rate from inclusion-initiated cracks in seeded PM alloys. A rotating and translating positioning system, with associated software, was devised to map the surface inclusions in low-cycle fatigue (LCF) test bars and to monitor the crack growth from these inclusions. The preceding graph illustrates the measured extension in fatigue cracks from inclusions on a seeded LCF test bar subjected to cyclic loading at a strain range of 0.8 percent and a strain ratio (max/min) of zero. Notice that the observed inclusions fall into three categories: some do not propagate at all (arrest), some propagate with a decreasing crack growth rate, and a few propagate at increasing rates that can be modeled by fracture mechanics. The following graph shows the measured inclusion-initiated crack growth rates from 10 interrupted LCF tests plotted against stress intensities calculated for semi-elliptical cracks with the observed surface lengths. The expected scatter in the crack growth rates for stress intensity ranges near threshold is observed. These data will be used to help determine the distribution in growth rates of cracks emanating from inclusions as well as the proportion of cracks that arrest under various loading conditions.

Predictive Engineering Tools for Injection-Molded Long-Carbon-Fiber Thermoplastic Composites - FY 2015 First Quarterly Report

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

Nguyen, Ba Nghiep; Fifield, Leonard S.; Kijewski, Seth A.

2015-01-29

During the first quarter of FY 2015, the following technical progress has been made toward project milestones: 1) Autodesk delivered a new research version of ASMI to PNNL. This version includes the improved 3D fiber orientation solver, and the reduced order model (ROM) for fiber length distribution using the proper orthogonal decomposition (POD) implemented in the mid-plane, dual-domain and 3D solvers. 2) Autodesk coordinated a conference paper with PNNL reporting ASMI mid-plane fiber orientation predictions compared with the measured data for two PlastiComp plaques. This paper was accepted for presentation at the 2015 Society for Plastics Engineers (SPE) ANTEC conference.more » 3) The University of Illinois (Prof. Tucker) assisted team members from Purdue with fiber orientation measurement techniques, including interpretation of off-axis cross sections. 4) The University of Illinois assisted Autodesk team members with software implementation of the POD approach for fiber length modeling, and with fiber orientation modeling. 5) The University of Illinois co-authored in the SPE ANTEC paper, participated with the team in discussions of plaque data and model results, and participated in the definition of go/no-go experiments and data. 6) Purdue University (Purdue) conducted fiber orientation measurements for 3 PlastiComp plaques: fast-fill 30wt% LCF/PP center-gated, fast-fill 50wt% LCF/PA66 edge-gated and fast-fill 50wt% LCF/PA66 center-gated plaques, and delivered the fiber orientation data for these plaques at the selected locations (named A, B, and C) to PNNL. However, the data for the fast-fill 50wt% LCF/PA66 edge-gated plaque exhibited unusual variations and could not be used for the model validation. Purdue will re-measure fiber orientation for this plaque. 7) Based on discussions with the University of Illinois Purdue explained the ambiguity in the measurements of the fiber orientation components. 8) PNNL discussed with team members to establish a go/no-go decision plan for the project and submitted the established plan to DOE. 9) PNNL performed ASMI mid-plane analyses for the fast-fill center-gated 30wt% LCF/PP and 50wt% LCF/PA66 plaques and compared the predicted fiber orientations with the measured data provided by Purdue at Locations A, B, and C on these plaques. 10) Based on discussions with the University of Illinois and Autodesk, PNNL proposed a procedure to adjust fiber orientation data for Location A of the center-gated plaques so that the data can be expressed and interpreted in the flow/cross-flow direction coordinate system. 11) PNNL tested the new ASMI version received from Autodesk, examined and discussed 3D fiber orientation predictions for PlastiComp plaques. 12) PlastiComp, Inc. (PlastiComp), Toyota Research Institute North America (Toyota) and Magna Exteriors and Interiors Corp. (Magna) participated in discussions with team members on the go/no-go plan and the issues related to fiber length measurements. Toyota continued the discussion with Magna on tool modification for molding the complex part in order to achieve the target fiber length in the part.« less

Does electropolishing improve the low-cycle fatigue behavior of a nickel-titanium rotary instrument in hypochlorite?

PubMed

Cheung, Gary S P; Shen, Ya; Darvell, Brian W

2007-10-01

The purpose of this study was to compare the low-cycle fatigue (LCF) behavior of electropolished and nonelectropolished nickel-titanium (NiTi) instruments of the same design in hypochlorite. Forty-five electropolished and 62 nonelectropolished NiTi engine files were subjected to rotational bending at various curvatures in 1.2% hypochlorite solution. Number of revolutions to failure, crack-initiation sites, extent of slow crack extension into the fracture cross-section, and surface-strain amplitude were noted. A linear relationship was found between LCF life and surface-strain amplitude for both groups, with no discernible difference between the two (p > 0.05). No electropolished instrument showed more than one crack origin, significantly fewer than for the nonelectropolished instruments (p < 0.05). The square root of crack extension and strain amplitude were inversely related. Although surface smoothness is enhanced by electropolishing, this did not protect the instrument from LCF failure.

Initial Assessment of the Effects of Nonmetallic Inclusions on Fatigue Life of Powder-Metallurgy-Processed Udimet(TM) 720

NASA Technical Reports Server (NTRS)

Gabb, T. P.; Telesman, J.; Kantzos, P. T.; Bonacuse, P. J.; Barrie, R. L.

2002-01-01

The fatigue lives of modern powder metallurgy (PM) disk alloys are influenced by variabilities in alloy microstructure and mechanical properties. These properties can vary due to the different steps of materials/component processing and machining. One of these variables, the presence of nonmetallic inclusions, has been shown to significantly degrade low-cycle fatigue (LCF) life. Nonmetallic inclusions are inherent defects in powder alloys that are a by-product of powder-processing techniques. Contamination of the powder can occur in the melt, during powder atomization, or during any of the various handling processes through consolidation. In modern nickel disk powder processing facilities, the levels of inclusion contamination have been reduced to less than 1 part per million by weight. Despite the efforts of manufacturers to ensure the cleanliness of their powder production processes, the presence of inclusions remains a source of great concern for the designer. the objective of this study was to investigate the effects on fatigue life of these inclusions. Since natural inclusions occur so infrequently, elevated levels of inclusions were carefully introduced in a nickel-based disk superalloy, Udimet 720 (registered trademark of Special Metals Corporation), produced using PM processing. Multiple strain-controlled fatigue tests were then performed on this material at 650 C. Analyses were performed to compare the LCF lives and failure initiation sites as functions of inclusion content and fatigue conditions. A large majority of the failures in specimens with introduced inclusions occurred at cracks initiating from inclusions at the specimen surface. The inclusions could reduce fatigue life by up to 100 times. These effects were found to be dependent on strain range and strain ratio. Tests at lower strain ranges and higher strain ratios produced larger effects of inclusions on life.

F101 Central Integrated Test Subsystem Evaluation.

DTIC Science & Technology

1980-02-01

These sensors are for fan rpm, core rpm, nozzle position, turbine blade temperature, engine exhaust gas tem- perature, lube oil pressure, lube oil...condition or a turbine blade (T4B) overtemperature condition, the CITS was to record the out-of-limits parameter every quarter-second that the engine was in...cycles on the turbine blades . The PLA cycle has become the most important LCF measurement to the YF101 and F1O engines in the B-1 Flight Test Program

Mechanical properties of turbine blade alloys in hydrogen at elevated temperatures

NASA Technical Reports Server (NTRS)

Deluca, D. P.

1981-01-01

The mechanical properties of single crystal turbine blade alloys in a gaseous hydrogen environment were determined. These alloys are proposed for use in space propulsion systems in pure or partial high pressure hydrogen environments at elevated temperatures. Mechanical property tests included: tensile, creep, low fatigue (LCF), and crack growth. Specimens were in both transverse and longitudinal directions relative to the casting solidification direction. Testing was conducted on solid specimens exposed to externally pressurized environments of gaseous hydrogen and hydrogen-enriched steam.

Molecular mechanisms of substrate recognition and specificity of botulinum neurotoxin serotype F.

PubMed

Chen, Sheng; Wan, Hoi Ying

2011-01-15

BoNTs (botulinum neurotoxins) are both deadly neurotoxins and natural toxins that are widely used in protein therapies to treat numerous neurological disorders of dystonia and spinal spasticity. Understanding the mechanism of action and substrate specificity of BoNTs is a prerequisite to develop antitoxin and novel BoNT-derived protein therapy. To date, there is a lack of detailed information with regard to how BoNTs recognize and hydrolyse the substrate VAMP-2 (vesicle-associated membrane protein 2), even though it is known to be cleaved by four of the seven BoNT serotypes, B, D, F, G and TeNT (tetanus neurotoxin). In the present study we dissected the molecular mechanisms of VAMP-2 recognition by BoNT serotype F for the first time. The initial substrate recognition was mediated through sequential binding of VAMP-2 to the B1, B2 and B3 pockets in LC/F (light chain of BoNT serotype F), which directed VAMP-2 to the active site of LC/F and stabilized the active site substrate recognition, where the P2, P1' and P2' sites of VAMP-2 were specifically recognized by the S2, S1' and S2' pockets of LC/F to promote substrate hydrolysis. The understanding of the molecular mechanisms of LC/F substrate recognition provides insights into the development of antitoxins and engineering novel BoNTs to optimize current therapy and extend therapeutic interventions.

Advanced Gear Alloys for Ultra High Strength Applications

NASA Technical Reports Server (NTRS)

Shen, Tony; Krantz, Timothy; Sebastian, Jason

2011-01-01

Single tooth bending fatigue (STBF) test data of UHS Ferrium C61 and C64 alloys are presented in comparison with historical test data of conventional gear steels (9310 and Pyrowear 53) with comparable statistical analysis methods. Pitting and scoring tests of C61 and C64 are works in progress. Boeing statistical analysis of STBF test data for the four gear steels (C61, C64, 9310 and Pyrowear 53) indicates that the UHS grades exhibit increases in fatigue strength in the low cycle fatigue (LCF) regime. In the high cycle fatigue (HCF) regime, the UHS steels exhibit better mean fatigue strength endurance limit behavior (particularly as compared to Pyrowear 53). However, due to considerable scatter in the UHS test data, the anticipated overall benefits of the UHS grades in bending fatigue have not been fully demonstrated. Based on all the test data and on Boeing s analysis, C61 has been selected by Boeing as the gear steel for the final ERDS demonstrator test gearboxes. In terms of potential follow-up work, detailed physics-based, micromechanical analysis and modeling of the fatigue data would allow for a better understanding of the causes of the experimental scatter, and of the transition from high-stress LCF (surface-dominated) to low-stress HCF (subsurface-dominated) fatigue failure. Additional STBF test data and failure analysis work, particularly in the HCF regime and around the endurance limit stress, could allow for better statistical confidence and could reduce the observed effects of experimental test scatter. Finally, the need for further optimization of the residual compressive stress profiles of the UHS steels (resulting from carburization and peening) is noted, particularly for the case of the higher hardness C64 material.

Low cycle fatigue and creep-fatigue behavior of Ni-based alloy 230 at 850 C

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

Chen, Xiang; Yang, Zhiqing; Sokolov, Mikhail A

Strain-controlled low cycle fatigue (LCF) and creep-fatigue testing of Ni-based alloy 230 were carried out at 850 C. The material creep-fatigue life decreased compared with its low cycle fatigue life at the same total strain range. Longer hold time at peak tensile strain further reduced the material creep-fatigue life. Based on the electron backscatter diffraction, a novel material deformation characterization method was applied, which revealed that in low cycle fatigue testing as the total strain range increased, the deformation was segregated to grain boundaries since the test temperature was higher than the material equicohesive temperature and grain boundaries became weakermore » regions compared with grains. Creep-fatigue tests enhanced the localized deformation, resulting in material interior intergranular cracking, and accelerated material damage. Precipitation in alloy 230 helped slip dispersion, favorable for fatigue property, but grain boundary cellular precipitates formed after material exposure to the elevated temperature had a deleterious effect on the material low cycle fatigue and creep-fatigue property.« less

VIS/NIR Spectroscopy to determine the spatial variation of the weathering degree in Paleogene clay soil - London Clay Formation

NASA Astrophysics Data System (ADS)

Nasser, Mohammed; Gibson, Andy, ,, Dr; Koor, Nick, ,, Dr; Gale, Professor Andy; Huggett, Jenny, ,, Dr; Branch, Steve

2017-04-01

The London Clay Formation (LCF) which underlies much of South-East England is hugely important as a construction medium. However, its geotechnical performance (shear strength, compressive strength, shrink-swell behaviour, etc. ) is greatly affected by its degree of weathering. Despite this importance, little attention has been focussed on a robust method to define and measure its degree of weathering. This is perhaps a result of a well-known colour change from bluish-grey to brown that accompanies 'weathering' and considered to be the result of oxidisation (Chandler and Apted 1988). Through wide experience, this definition is normally effective, but it is perhaps subjective and reliant on the experience of the investigator and the ability to observe samples or exposures. More objective investigation, typically using SEM is not normally economically feasible or expedient for construction works. We propose a simple, robust method to characterise the degree of weathering in the LCF using reflective or Visible-Near-InfraRed-Spectroscopy (VNIRS). 24 samples were extracted from 2 boreholes drilled in the Hampstead area of London to depths of 12 m within the uppermost Claygate Member of the LCF. VNIRS spectra (350-2500 nm) were measured from all samples and compared with XRD, XRF, SEM and PSD results on the same samples. Results show increased magnitude of absorption features related to clay mineralogy around 1400, 1900 and 2200 nm to a depth of 5 m beneath ground level. Beneath this depth, the absorption features show little variation. SEM analyses show corresponding changes in the degradation of pyrite crystals and individual clay (illite/smectite). These preliminary results show that there is a good potential for VNIRS spectroscopy to determine the variation of weathering in the LCF.

Predictive Engineering Tools for Injection-Molded Long-Carbon-Thermoplastic Composites: Weight and Cost Analyses

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

Nguyen, Ba Nghiep; Fifield, Leonard S.; Gandhi, Umesh N.

This project proposed to integrate, optimize and validate the fiber orientation and length distribution models previously developed and implemented in the Autodesk Simulation Moldflow Insight (ASMI) package for injection-molded long-carbon-fiber thermoplastic composites into a cohesive prediction capability. The current effort focused on rendering the developed models more robust and efficient for automotive industry part design to enable weight savings and cost reduction. The project goal has been achieved by optimizing the developed models, improving and integrating their implementations in ASMI, and validating them for a complex 3D LCF thermoplastic automotive part (Figure 1). Both PP and PA66 were used asmore » resin matrices. After validating ASMI predictions for fiber orientation and fiber length for this complex part against the corresponding measured data, in collaborations with Toyota and Magna PNNL developed a method using the predictive engineering tool to assess LCF/PA66 complex part design in terms of stiffness performance. Structural three-point bending analyses of the complex part and similar parts in steel were then performed for this purpose, and the team has then demonstrated the use of stiffness-based complex part design assessment to evaluate weight savings relative to the body system target (≥ 35%) set in Table 2 of DE-FOA-0000648 (AOI #1). In addition, starting from the part-to-part analysis, the PE tools enabled an estimated weight reduction for the vehicle body system using 50 wt% LCF/PA66 parts relative to the current steel system. Also, from this analysis an estimate of the manufacturing cost including the material cost for making the equivalent part in steel has been determined and compared to the costs for making the LCF/PA66 part to determine the cost per “saved” pound.« less

Effect of anisotropy and texture on the low cycle fatigue behavior of Inconel 718 processed via electron beam melting

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

Kirka, Michael M.; Greeley, Duncan A.; Hawkins, Charles S.

Here in this study, the impact of texture (columnar/equiax grain structure) and influence of material orientation on the low cycle fatigue (LCF) behavior of hot isostatic pressed (HIP) and heat-treated Inconel 718 fabricated through electron beam melting (EBM) is investigated. Material was tested both parallel and perpendicular (transverse) to the build direction. In all instances, the EBM HIP and heat-treated Inconel 718 performed similarly or exceeded the LCF life of wrought Inconel 718 plate and bar stock under fully reversed strain-controlled loading at 650 °C. Amongst the textures, the columnar grains oriented parallel to the build direction exhibited the highestmore » life on average compared to the transverse columnar and equiax EBM material. Further, in relation to the reference wrought material the parallel columnar grain material exhibited a greater life. While a negligible life difference was observed in the equiax grained material between the two orientations, a consistently lower accumulated inelastic strain was measured for the material loaded parallel to the build direction than the transverse orientation. Failure of the parallel columnar material occurred in a transgranular manner with cracks emanating from the surface whereas the transverse columnar material failed in a intergranular manner, with crack growth occurring through repeated rupture of oxide at the crack-tip. Finally, in the case of the equiax material, an influence of material orientation was not observed on the failure mechanism with crack propagation occurring through a combination of debonded/cracked carbides and void formation along twin boundaries resulting in a mixture of intergranular and transgranular crack propagation.« less

Effect of anisotropy and texture on the low cycle fatigue behavior of Inconel 718 processed via electron beam melting

DOE PAGES

Kirka, Michael M.; Greeley, Duncan A.; Hawkins, Charles S.; ...

2017-09-11

Here in this study, the impact of texture (columnar/equiax grain structure) and influence of material orientation on the low cycle fatigue (LCF) behavior of hot isostatic pressed (HIP) and heat-treated Inconel 718 fabricated through electron beam melting (EBM) is investigated. Material was tested both parallel and perpendicular (transverse) to the build direction. In all instances, the EBM HIP and heat-treated Inconel 718 performed similarly or exceeded the LCF life of wrought Inconel 718 plate and bar stock under fully reversed strain-controlled loading at 650 °C. Amongst the textures, the columnar grains oriented parallel to the build direction exhibited the highestmore » life on average compared to the transverse columnar and equiax EBM material. Further, in relation to the reference wrought material the parallel columnar grain material exhibited a greater life. While a negligible life difference was observed in the equiax grained material between the two orientations, a consistently lower accumulated inelastic strain was measured for the material loaded parallel to the build direction than the transverse orientation. Failure of the parallel columnar material occurred in a transgranular manner with cracks emanating from the surface whereas the transverse columnar material failed in a intergranular manner, with crack growth occurring through repeated rupture of oxide at the crack-tip. Finally, in the case of the equiax material, an influence of material orientation was not observed on the failure mechanism with crack propagation occurring through a combination of debonded/cracked carbides and void formation along twin boundaries resulting in a mixture of intergranular and transgranular crack propagation.« less

Phenomenological aspects of fatigue cracking in as-received and hardened F82H modified steel exposed to lithiated water with dissolved hydrogen at 240°C

NASA Astrophysics Data System (ADS)

Maday, Marie-Françoise

2000-12-01

The low cycle fatigue (LCF) behaviour of F82H modified steel with three different degrees of hardness produced by specific thermal treatments has been investigated at 240°C under load control, in oxygen-free lithiated solutions containing either no or 2 ppm dissolved hydrogen. In all cases, it was found that the aqueous environments reduced the fatigue life of the material and promoted fracture modes different from those observed in air tests; the fracture modes comprised intergranular and transgranular quasi-cleavage separations as well as microvoid coalescence, which depended on material conditions and water chemistry. All these features were ascribed to a hydrogen-assisted-cracking (HAC) phenomenon, as the basic mechanism for controlling the fatigue behaviour of various F82H heats in lithiated solutions. The observed differences in HAC paths are discussed from the standpoint of material microstructural and substructural parameters.

Transformation of Silver Nanoparticles in Sewage Sludge during Incineration.

PubMed

Meier, Christoph; Voegelin, Andreas; Pradas del Real, Ana; Sarret, Geraldine; Mueller, Christoph R; Kaegi, Ralf

2016-04-05

Silver nanoparticles (Ag-NP) discharged into the municipal sewer system largely accumulate in the sewage sludge. Incineration and agricultural use are currently the most important strategies for sewage sludge management. Thus, the behavior of Ag-NP during sewage sludge incineration is essential for a comprehensive life cycle analysis and a more complete understanding of the fate of Ag-NP in the (urban) environment. To address the transformation of Ag-NP during sewage sludge incineration, we spiked metallic Ag(0)-NP to a pilot wastewater treatment plant and digested the sludge anaerobically. The sludge was then incinerated on a bench-scale fluidized bed reactor in a series of experiments under variable conditions. Complementary results from X-ray absorption spectroscopy (XAS) and electron microscopy-energy dispersive X-ray (EM-EDX) analysis revealed that Ag(0)-NP transformed into Ag2S-NP during the wastewater treatment, in agreement with previous studies. On the basis of a principal component analysis and subsequent target testing of the XAS spectra, Ag(0) was identified as a major Ag component in the ashes, and Ag2S was clearly absent. The reformation of Ag(0)-NP was confirmed by EM-EDX. The fraction of Ag(0) of the total Ag in the ashes was quantified by linear combination fitting (LCF) of XAS spectra, and values as high as 0.8 were found for sewage sludge incinerated at 800 °C in a synthetic flue gas atmosphere. Low LCF totals (72% to 94%) indicated that at least one relevant reference spectrum was missing in the LCF analysis. The presence of spherical Ag-NP with a diameter of <50 nm extending into the sub-nm range was revealed by electron microscopy analyses. The rapid formation of Ag(0)-NP from Ag2S during sewage sludge incineration, as demonstrated in this study, needs to be considered in the life cycle assessment of engineered Ag-NP.

Economic evaluation of United States ethanol production from ligno-cellulosic feedstocks

NASA Astrophysics Data System (ADS)

Choi, Youn-Sang

This paper evaluates the economic feasibility and economy-wide impacts of the U. S. ethanol production from lignocellulosic feedstocks (LCF) using Tennessee Valley Authority's (TVA's) dilute acid hydrolysis process. A nonlinear mathematical programming model of a single ethanol producer, whose objective is profit maximization, is developed. Because of differences in their chemical composition and production process, lignocellulosic feedstocks are divided into two groups: Biomass feedstocks, which refer to crop residues, energy crops and woody biomass, and municipal solid waste (MSW). Biomass feedstocks are more productive and less costly in producing ethanol and co-products, while MSW generates an additional income to the producer from a tipping fee and recycling. The analysis suggests that, regardless of types of feedstocks used, TVA's conversion process can enhance the economic viability of ethanol production as long as furfural is produced from the hemicellulose fraction of feedstocks as a co-product. The high price of furfural makes it a major factor in determining the economic feasibility of ethanol production. Along with evaluating economic feasibility of LCF-to-ethanol production, the optimal size of a plant producing ethanol using TVA's conversion process is estimated. The larger plant would have the advantage of economies of scale, but also have a disadvantage of increased collection and transportation costs for bulky biomass from more distant locations. We assume that the plant is located in the state of Missouri and utilizes only feedstocks produced in the state. The results indicate that the size of a plant using Biomass feedstocks is much bigger than one using MSW. The difference of plant sizes results from plant location and feedstock availability. One interesting finding is that energy crops are not feasible feedstocks for LCF-to-ethanol production due to their high price. Next, a static CGE model is developed to estimate the U.S. economy-wide impacts of the current ethanol production with a government subsidy and the LCF-to-ethanol production using TVA's dilute acid hydrolysis process. The model is innovative in three ways. First, a production subsidy is explicitly included in the model. Second, co-products are explicitly accounted for in ethanol production. Third, ethanol and gasoline are treated as perfect demand substitutes, as are the co-products and the manufacturing sector's output. The CGE model shows that current ethanol production expands grain crop production by creating an additional demand. In contrast, LCF-to-ethanol production has adverse impacts on grain crop production because Biomass feedstocks substitute for grain in the production of ethanol. The LCF-to-ethanol production also discourages the manufacturing industry because co-products displace a part of intermediate input demand for manufacturing outputs. It is also found that, even though ethanol production using TVA's conversion technology with MSW is economically viable, it is not favorable to the economy. Finally, the results suggest that ethanol production from Biomass feedstocks using TVA's dilute acid hydrolysis process is beneficial to the U.S. economy.

Computational logic: its origins and applications.

PubMed

Paulson, Lawrence C

2018-02-01

Computational logic is the use of computers to establish facts in a logical formalism. Originating in nineteenth century attempts to understand the nature of mathematical reasoning, the subject now comprises a wide variety of formalisms, techniques and technologies. One strand of work follows the 'logic for computable functions (LCF) approach' pioneered by Robin Milner, where proofs can be constructed interactively or with the help of users' code (which does not compromise correctness). A refinement of LCF, called Isabelle, retains these advantages while providing flexibility in the choice of logical formalism and much stronger automation. The main application of these techniques has been to prove the correctness of hardware and software systems, but increasingly researchers have been applying them to mathematics itself.

Computational logic: its origins and applications

PubMed Central

2018-01-01

Computational logic is the use of computers to establish facts in a logical formalism. Originating in nineteenth century attempts to understand the nature of mathematical reasoning, the subject now comprises a wide variety of formalisms, techniques and technologies. One strand of work follows the ‘logic for computable functions (LCF) approach’ pioneered by Robin Milner, where proofs can be constructed interactively or with the help of users’ code (which does not compromise correctness). A refinement of LCF, called Isabelle, retains these advantages while providing flexibility in the choice of logical formalism and much stronger automation. The main application of these techniques has been to prove the correctness of hardware and software systems, but increasingly researchers have been applying them to mathematics itself. PMID:29507522

Effectiveness of Shot Peening In Suppressing Fatigue Cracking At Non-Metallic Inclusions In Udimet(Registered Trademark)720

NASA Technical Reports Server (NTRS)

Barrie, Robert L.; Gabb, Timothy P.; Telesman, Jack; Kantzos, Peter T.; Prescenzi, Anthony; Biles, T.; Bonacuse, P. J.

2006-01-01

The fatigue lives of modern powder metallurgy disk alloys can be reduced over an order of magnitude by cracking at inherent non-metallic inclusions. The objective of this work was to study the effectiveness of shot peening in suppressing LCF crack initiation and growth at surface nonmetallic inclusions. Inclusions were carefully introduced at elevated levels during powder metallurgy processing of the nickel-base disk superalloy Udimet 720. Multiple strain-controlled fatigue tests were then performed on machined specimens with and without shot peened test sections at 427 C and 650 C. The low cycle fatigue lives and failure initiation sites varied as functions of inclusion content, shot peening, and fatigue conditions. A large majority of the failures in as-machined specimens with the introduced inclusions occurred at cracks initiating from inclusions intersecting the specimen surface. These inclusions reduced fatigue life by up to 100X, when compared to lives of material without inclusions residing at specimen surface. Large inclusions produced the greatest reductions in life for tests at low strain ranges and high strain ratios. Shot peening improved life in many cases by reducing the most severe effects of inclusions.

A Predictive Framework for Thermomechanical Fatigue Life of High Silicon Molybdenum Ductile Cast Iron Based on Considerations of Strain Energy Dissipation

NASA Astrophysics Data System (ADS)

Avery, Katherine R.

Isothermal low cycle fatigue (LCF) and anisothermal thermomechanical fatigue (TMF) tests were conducted on a high silicon molybdenum (HiSiMo) cast iron for temperatures up to 1073K. LCF and out-of-phase (OP) TMF lives were significantly reduced when the temperature was near 673K due to an embrittlement phenomenon which decreases the ductility of HiSiMo at this temperature. In this case, intergranular fracture was predominant, and magnesium was observed at the fracture surface. When the thermal cycle did not include 673K, the failure mode was predominantly transgranular, and magnesium was not present on the fracture surface. The in-phase (IP) TMF lives were unaffected when the thermal cycle included 673K, and the predominant failure mode was found to be transgranular fracture, regardless of the temperature. No magnesium was present on the IP TMF fracture surfaces. Thus, the embrittlement phenomenon was found to contribute to fatigue damage only when the temperature was near 673K and a tensile stress was present. To account for the temperature- and stress-dependence of the embrittlement phenomenon on the TMF life of HiSiMo cast iron, an original model based on the cyclic inelastic energy dissipation is proposed which accounts for temperature-dependent differences in the rate of fatigue damage accumulation in tension and compression. The proposed model has few empirical parameters. Despite the simplicity of the model, the predicted fatigue life shows good agreement with more than 130 uniaxial low cycle and thermomechanical fatigue tests, cyclic creep tests, and tests conducted at slow strain rates and with hold times. The proposed model was implemented in a multiaxial formulation and applied to the fatigue life prediction of an exhaust manifold subjected to severe thermal cycles. The simulation results show good agreement with the failure locations and number of cycles to failure observed in a component-level experiment.

Phonological Interpretation into Preordered Algebras

NASA Astrophysics Data System (ADS)

Kubota, Yusuke; Pollard, Carl

We propose a novel architecture for categorial grammar that clarifies the relationship between semantically relevant combinatoric reasoning and semantically inert reasoning that only affects surface-oriented phonological form. To this end, we employ a level of structured phonology that mediates between syntax (abstract combinatorics) and phonology proper (strings). To notate structured phonologies, we employ a lambda calculus analogous to the φ-terms of [8]. However, unlike Oehrle's purely equational φ-calculus, our phonological calculus is inequational, in a way that is strongly analogous to the functional programming language LCF [10]. Like LCF, our phonological terms are interpreted into a Henkin frame of posets, with degree of definedness ('height' in the preorder that interprets the base type) corresponding to degree of pronounceability; only maximal elements are actual strings and therefore fully pronounceable. We illustrate with an analysis (also new) of some complex constituent-order phenomena in Japanese.

Predictive engineering tools for injection-molded long-carbon-fiber thermoplastic composites - FY 2015 third quarterly report

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

Nguyen, Ba Nghiep; Fifield, Leonard S.; Mori, Steven

During the third quarter of FY 2015, the following technical progress has been made toward project milestones: 1) Magna oversaw the tool build and prepared the molding plan for the complex part of Phase II. 2) PlastiComp hosted a visit by Magna and Toyota on April 23rd to finalize the molding scope and schedule. The plan for molding trials including selection of molding parameters for both LFT and D-LFT for the U-shape complex part was established. 3) Toyota shipped the U-shape complex part tool to Magna on May 28th, 2015. 4) Plasticomp provided 30wt% LCF/PP and 30wt% LCF/PA66 compounded pelletsmore » to Magna for molding the complex part. 5) Magna performed preliminary molding trials on June 2nd, 2015 to validate wall thickness, fill profile, tool temperature and shot size requirements for the complex part. 6) Magna performed the first complex part run on June 16th and 17th, 2015 at Magna’s Composite Centre of Excellence in Concord, ON, Canada. Dale Roland of Plasticomp, and Umesh Gandhi of Toyota also attended the molding. 7) Magna discussed and finalized the plan with PNNL and the team for cutting samples from molded parts at selected locations for fiber orientation and length measurements. 8) Magna provided the computer-aided design (CAD) files of the complex parts with and without ribs to PNNL and Autodesk to build the corresponding ASMI models for injection molding simulations. Magna also provided the actual parameters used. 9) Plasticomp’s provided knowledge and experience of molding LCF materials essential to the successful molding of the parts including optimization of fill speed, tool temperatures, and plasticizing conditions for the 30wt% LCF/PP and 30wt% LCF/PA66 materials in both rib and non-rib versions. 10) Magna molded additional parts for evaluation of mechanical property testing including torsional stiffness on June 29th and 30th, 2015 at Magna’s Composite Center of Excellence. 11) Toyota began preparation for the torsion test of the specimens. Preparation of a computer-aided engineering (CAE) model to predict the performance is in progress. 12) Autodesk fixed an error in the implementation of the proper orthogonal decomposition (POD) calculation of fiber length that had caused the ASMI solution to crash and provided an updated build of ASMI containing the fix. 13)Autodesk reviewed and provided feedback for the complex part molding and measurement locations. 14) Autodesk provided support to set up the workflow for ASMI-ABAQUS® analysis, and provided a fix and workaround for a bug in the ASMI-ABAQUS® output command. 15) Autodesk helped build ASMI analysis models for the complex parts with and without ribs. 16) Autodesk worked on improving the orientation prediction accuracy in the shearing layer for 3D meshes based on comparison to measured data of the plaque moldings. 17) PNNL installed a new ASMI version received from Autodesk and performed comparative analyses to assess mid-plane versus 3D fiber length predictions using the full fiber length model and the reduced-order model (ROM) using POD. 18) PNNL presented the project scope, accomplishments, significant results and future plans to DOE and the USCAR Materials Tech Team on June 3rd, 2015. 19) PNNL discussed the cutting of samples from molded parts and finalized a plan with Magna and the team suggesting the sample size, locations and number of samples per location. 20) PNNL and Autodesk built ASMI models for the complex parts with and without ribs, and preliminary analyses of the part with ribs were conducted using the actual molding parameters received from Magna. 21) PNNL worked on a procedure to extract fiber orientation and length results from a 3D ASMI analysis to a 3D ABAQUS model. This procedure is essential to import ASMI fiber orientation and length to a 3D ABAQUS model of the part allowing future part structural analysis for weight reduction study.« less

Effectiveness of Shot Peening in Suppressing Fatigue Cracking at Non-Metallic Inclusions in Udimet(trademark) 720

NASA Technical Reports Server (NTRS)

Barrie, Robert L.; Gabb, Timothy P.; Telesman, Jack; Kantzos, Peter T.; Prescenzi, Anthony; Biles, Tiffany; Bonacuse, Peter J.

2005-01-01

The fatigue lives of modern powder metallurgy disk alloys can be reduced by over an order of magnitude by surface cracking at inherent non-metallic inclusions. The objective of this work was to study the effectiveness of shot peening in suppressing LCF crack initiation and growth at surface nonmetallic inclusions. Inclusions were carefully introduced at elevated levels during powder metallurgy processing of the nickel-base disk superalloy Udimet 720. Multiple strain-controlled fatigue tests were then performed on machined specimens at 427 and 650 C in peened and unpeened conditions. Analyses were performed to compare the low cycle fatigue lives and failure initiation sites as a function of inclusion content, shot peening, and fatigue conditions. A large majority of the failures in as-machined specimens with introduced inclusions occurred at cracks initiating from inclusions intersecting the specimen surface. The inclusions could reduce fatigue life by up to 100X. Large inclusions had the greatest effect on life in tests at low strain ranges and high strain ratios. Shot peening can be used to improve life in these conditions by reducing the most severe effects of inclusions.

SEROEPIDEMIOLOGY

EPA Science Inventory

ELIZA and Western blot assays have been used to detect serological responses to Cryptosporidium antigens. 1-16. A Western blot assay htat uses a miniblot was developed by the Loveland Clinic Foundation (LCF) with funding from the U.S. Environmental Protection Agency (EPA). This...

Effects of polyalkylene glycols and fatty acid soaps on properties of synthetic lubricating-cooling fluids

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

Stulii, A.A.

1983-01-01

The lack of any effect of the polyalkylene glycols on the series of properties of the fatty acid soaps was confirmed by replacing the PEG-35 in the synthetic lubricating-cooling fluid (LCF) by a polyethylene glycol with a molecular weight of 400 or 6000, a propylene oxide oligomer with a molecular weight of 700, or a copolymer of ethylene and propylene oxides (Pluronic 44, Pluriol PE-6400, Hydropol 200). Attempts to select surfactants and optimal concentrations in synthetic LCFs based on polyalkylene glycols. Indicates that of the studied soaps, those of the most interest are the triethanolamine soaps of individual C/sub 6/-C/submore » 10/ fatty acids and commercial mixed C/sub 7/-C/sub 9/ synthetic fatty acids. Finds that the polyalkylene glycols and the indicated soaps supplement each other, imparting the required set of properties to the LCF.« less

Stress analysis, thermomechanical fatique evaluation, and root subcomponent testing of gamma/gamma prime-delta eutectic alloy

NASA Technical Reports Server (NTRS)

Sheffler, K. D.; Jackson, J. J.

1976-01-01

Thermomechanical fatigue (TMF) and root subcomponent tensile, creep, and low cycle fatigue (LCF) tests were conducted to determine the capability of a fully lamellar directionally solidified eutectic alloy to sustain the airfoil thermal fatigue and root attachment loads anticipated in advanced, hollow, high work turbine blades. A three dimensional finite element elastic stress analysis was performed on typical advanced hollow eutectic airfoil and root-platform designs to determine appropriate conditions for these tests. Results of TMF tests conducted on longitudinal specimens (stress axis parallel to the solidification direction) containing a simulated leading edge cooling hole pattern indicated the longitudinal TMF properties to be more than adequate for the particular advanced hollow blade analyzed, with the strain range for a 10,000 cycle life being more than 50% above the maximum strain range calculated for the advanced hollow blade.

High-temperature low-cycle-fatigue and crack-growth behaviors of three superalloys: HASTELLOY X, HAYNES 230, and HAYNES 188

NASA Astrophysics Data System (ADS)

Lu, Yulin

Low cycle fatigue (LCF) and fatigue crack growth (FCG) experiments on three superalloys HASTELLOY X, HAYNES 230, and HAYNES 188 have been conducted at temperatures from 649 to 982°C. Hold times were imposed at the maximum strain or load to investigate the hold-time effect. In general, the fatigue life decreased as the temperature or hold time increased. However, for the HAYNES 230 alloy at total strain ranges higher than 1.0% and without a hold time, the LCF life was longer at 927°C than at 816°C. This "abnormal" behavior was found to result from the smaller plastic strain amplitude at half-life at 927°C than that at 816°C. An increase in the temperature and/or the introduction of a hold time decreased the hardening rate and increased the softening rate for all the three alloys. The introduction of a hold time and/or the increase of the test temperature progressively changed the fracture mode from the transgranular to mixed trans/inter-granular, then to intergranular feature. Within the two phases of the fatigue process, crack initiation was more severely influenced by the change of the hold time and/or temperature. The FCG data of HASTELLOY X and HAYNES 230 alloys were analyzed with an emphasis on hold-time and temperature effects. The crack grew faster at a higher temperature and a longer hold time. Fracture-mechanics parameters, C*, Ct, and (Ct)avg, were applied to correlate the crack-growth rates. The fatigue-cracking path was mainly transgranular at 816 and 927°C. The cracking path became dominantly intergranular if the hold time increased to 2 min, indicating that the time-dependent damage mechanisms were in control. The Ct and (Ct)avg parameters were capable of consolidating time dependent crack growth rate from different temperatures and alloys. The tests were conducted in air. Therefore, the fracture surfaces were frequently covered with a dark layer of oxides, making fracture feature difficult to identify under scanning-electron-microscopy. To overcome this problem, an oxide-stripping technique has been developed. The sample is first boiled in a potassium permanganate solution for 1 h, and then electrolytically cleaned in an alkaline solution for 5 min.

An effective intervention algorithm for promoting cooperation in the prisoner's dilemma game with multiple stable states

NASA Astrophysics Data System (ADS)

Li, Y. S.; Xu, C.; Hui, P. M.

2018-07-01

Multiple stable states, hysteresis, sensitivity to initial distributions, and a control algorithm for promoting cooperation are studied in an evolutionary prisoner's dilemma with agents connected into a regular random network. A system could evolve into states of different cooperative frequencies xc in different runs, even starting with the same initial cooperative frequency xc(in) and payoff parameters. For a large reward R, some values of xc(in) either take the system to a group of low cooperative frequency (LCF) states or to a few high cooperative frequency (HCF) states. These states differ by their network structures, with cooperative players connected into ring-like structure in LCF states and compact clusters in HCF states. Hysteresis in xc is observed when R is swept down and up, when the final state of the previous R is used as the initial state of the next R. The analysis led us to propose a closed pack cluster algorithm that gives HCF states effectively. The algorithm intervenes the system at some point in time by selectively switching some non-cooperative D-agents into cooperative C-agents at the peripheral of an existing cluster of C-agents. It ensures protection of a small C-cluster from which more cooperation can be induced. Practically, a governing body may first allow a society to evolve freely and then derive suitable policy to promote selected pockets of good practices for attaining a higher level of common good.

Land Ice Verification and Validation Kit

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

2015-07-15

To address a pressing need to better understand the behavior and complex interaction of ice sheets within the global Earth system, significant development of continental-scale, dynamical ice-sheet models is underway. The associated verification and validation process of these models is being coordinated through a new, robust, python-based extensible software package, the Land Ice Verification and Validation toolkit (LIVV). This release provides robust and automated verification and a performance evaluation on LCF platforms. The performance V&V involves a comprehensive comparison of model performance relative to expected behavior on a given computing platform. LIVV operates on a set of benchmark and testmore » data, and provides comparisons for a suite of community prioritized tests, including configuration and parameter variations, bit-4-bit evaluation, and plots of tests where differences occur.« less

Review of the AGARD S and M panel evaluation program of the NASA-Lewis SRP approach to high-temperature LCF life prediction

NASA Technical Reports Server (NTRS)

Hirschberg, M. H.

1978-01-01

Twenty laboratories in six countries participated in testing their own materials of interest under their own laboratory conditions. In this way the results obtained provided validation of the Strainrange Partitioning (SRP) method for a wide range of materials and insured maximum usefulness to each of the participating laboratories. The various investigators shared their findings, thus providing the basis for an in-depth evaluation of the SRP method. While the results were variable from laboratory to laboratory, most investigators agreed that the SRP method was a significant step toward life prediction in the presence of high temperature and cyclic stresses.

Effects of Agave tequilana fructans with different degree of polymerization profiles on the body weight, blood lipids and count of fecal Lactobacilli/Bifidobacteria in obese mice.

PubMed

Márquez-Aguirre, Ana Laura; Camacho-Ruiz, Rosa Maria; Arriaga-Alba, Myriam; Padilla-Camberos, Eduardo; Kirchmayr, Manuel Reinhart; Blasco, José Luis; González-Avila, Marisela

2013-08-01

Fructans are dietary fibers with beneficial effects on the gastrointestinal physiology and offer a promising approach for the treatment of some metabolic disorders associated with obesity. In vitro and in vivo studies were developed to test the safety of fructans obtained from Agave tequilana Weber var. azul. Additionally, an in vivo experiment using a diet-induced obesity model was performed to compare the effect of agave fructans with different degree of polymerization (DP) profiles: agave fructans with DP > 10 (LcF), agave FOS with DP < 10 (ScF), and agave fructans with and without demineralization (dTF, TF) versus commercial chicory fructans (OraftiSynergy1™) on the body weight change, fat, total cholesterol, triglycerides and count of fecal Lactobacillus spp. and Bifidobacterium spp. Results showed that A. tequilana fructans were not mutagenic and were safe even at a dose of 5 g per kg b.w. Obese mice that received ScF showed a significant decrease in body weight gain, fat tissue and total cholesterol without increasing the count of fecal Bifidobacteria. Whereas, obese mice that received LcF and TF showed decreased triglycerides and an increased count of fecal Bifidobacteria. Interestingly, although obese mice that received dTF did not show changes in body weight gain, fat tissue, total cholesterol or triglycerides, they showed an increase in the count of Bifidobacteria. These results demonstrate that both the degree of polymerization and the demineralization process can influence the biological activity of agave fructans.

Flavanol-rich cocoa consumption enhances exercise-induced executive function improvements in humans.

PubMed

Tsukamoto, Hayato; Suga, Tadashi; Ishibashi, Aya; Takenaka, Saki; Tanaka, Daichi; Hirano, Yoshitaka; Hamaoka, Takafumi; Goto, Kazushige; Ebi, Kumiko; Isaka, Tadao; Hashimoto, Takeshi

2018-02-01

Aerobic exercise is known to acutely improve cognitive functions, such as executive function (EF) and memory function (MF). Additionally, consumption of flavanol-rich cocoa has been reported to acutely improve cognitive function. The aim of this study was to determine whether high cocoa flavanol (CF; HCF) consumption would enhance exercise-induced improvement in cognitive function. To test this hypothesis, we examined the combined effects of HCF consumption and moderate-intensity exercise on EF and MF during postexercise recovery. Ten healthy young men received either an HCF (563 mg of CF) or energy-matched low CF (LCF; 38 mg of CF) beverage 70 min before exercise in a single-blind counterbalanced manner. The men then performed moderate-intensity cycling exercise at 60% of peak oxygen uptake for 30 min. The participants performed a color-word Stroop task and face-name matching task to evaluate EF and MF, respectively, during six time periods throughout the experimental session. EF significantly improved immediately after exercise compared with before exercise in both conditions. However, EF was higher after HCF consumption than after LCF consumption during all time periods because HCF consumption improved EF before exercise. In contrast, HCF consumption and moderate-intensity exercise did not improve MF throughout the experiment. The present findings demonstrated that HCF consumption before moderate-intensity exercise could enhance exercise-induced improvement in EF, but not in MF. Therefore, we suggest that the combination of HCF consumption and aerobic exercise may be beneficial for improving EF. Copyright © 2017 Elsevier Inc. All rights reserved.

Multi-destination trip patterns

Treesearch

Susan I. Stewart; Christine A. Vogt

1996-01-01

In a 1993 article in Annals, Leu, Crompton, and Fesenmaier (LCF) presented a model of multi-destination pleasure trips. In the article, they question the practice of modeling pleasure trips as single destination trips, and put forward conceptual arguments suggesting that most trips "are not simple origin-destination trips: (1993:291) but...

Assessment of Low Cycle Fatigue Behavior of Powder Metallurgy Alloy U720

NASA Technical Reports Server (NTRS)

Gabb, Tomothy P.; Bonacuse, Peter J.; Ghosn, Louis J.; Sweeney, Joseph W.; Chatterjee, Amit; Green, Kenneth A.

2000-01-01

The fatigue lives of modem powder metallurgy disk alloys are influenced by variabilities in alloy microstructure and mechanical properties. These properties can vary as functions of variables the different steps of materials/component processing: powder atomization, consolidation, extrusion, forging, heat treating, and machining. It is important to understand the relationship between the statistical variations in life and these variables, as well as the change in life distribution due to changes in fatigue loading conditions. The objective of this study was to investigate these relationships in a nickel-base disk superalloy, U720, produced using powder metallurgy processing. Multiple strain-controlled fatigue tests were performed at 538 C (1000 F) at limited sets of test conditions. Analyses were performed to: (1) assess variations of microstructure, mechanical properties, and LCF failure initiation sites as functions of disk processing and loading conditions; and (2) compare mean and minimum fatigue life predictions using different approaches for modeling the data from assorted test conditions. Significant variations in life were observed as functions of the disk processing variables evaluated. However, the lives of all specimens could still be combined and modeled together. The failure initiation sites for tests performed at a strain ratio R(sub epsilon) = epsilon(sub min)/epsilon(sub max) of 0 were different from those in tests at a strain ratio of -1. An approach could still be applied to account for the differences in mean and maximum stresses and strains. This allowed the data in tests of various conditions to be combined for more robust statistical estimates of mean and minimum lives.

Thermal-mechanical fatigue behavior of nickel-base superalloys

NASA Technical Reports Server (NTRS)

Pelloux, R. M.; Marchand, N.

1986-01-01

The main achievements of a 36-month research program are presented. The main objective was to gain more insight into the problem of crack growth under thermal mechanical fatigue (TMF) conditions. This program was conducted at M.I.T. for the period of September 1982 to September 1985. The program was arranged into five technical tasks. Under Task I, the literature of TMF data was reviewed. The goal was to identify the crack propagation conditions in aircraft engines (hot section) and to assess the validity of conventional fracture mechanics parameters to address TMF crack growth. The second task defined the test facilities, test specimen and the testing conditions needed to establish the effectiveness of data correlation parameters identified in Task I. Three materials (Inconel X-750, Hastelloy-X, and B-1900) were chosen for the program. Task II was accomplished in collaboration with Pratt & Whitney Aircraft engineers. Under Task III, a computerized testing system to measure the TMF behavior (LCF and CG behaviors) of various alloys systems was built. The software used to run isothermal and TMF tests was also developed. Built around a conventional servohydraulic machine, the system is capable of push-pull tests under stress or strain and temperature controlled conditions in the temperature range of 25C to 1050C. A crack propagation test program was defined and conducted under Task IV. The test variables included strain range, strain rate (frequency) and temperature. Task V correlated and generalized the Task IV data for isothermal and variable temperature conditions so that several crack propagation parameters could be compared and evaluated. The structural damage (mode of cracking and dislocation substructure) under TMF cycling was identified and contrasted with the isothermal damage to achieve a sound fundamental mechanistic understanding of TMF.

77 FR 55166 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-07

... ``partial cycle event,'' specify a method of calculating the low cycle fatigue (LCF) life limit using... or continuing to count the full and partial low fatigue cycle events and recording on the component... distinction; and 4. Will not have a significant economic impact, positive or negative, on a substantial number...

The scaling issue: scientific opportunities

NASA Astrophysics Data System (ADS)

Orbach, Raymond L.

2009-07-01

A brief history of the Leadership Computing Facility (LCF) initiative is presented, along with the importance of SciDAC to the initiative. The initiative led to the initiation of the Innovative and Novel Computational Impact on Theory and Experiment program (INCITE), open to all researchers in the US and abroad, and based solely on scientific merit through peer review, awarding sizeable allocations (typically millions of processor-hours per project). The development of the nation's LCFs has enabled available INCITE processor-hours to double roughly every eight months since its inception in 2004. The 'top ten' LCF accomplishments in 2009 illustrate the breadth of the scientific program, while the 75 million processor hours allocated to American business since 2006 highlight INCITE contributions to US competitiveness. The extrapolation of INCITE processor hours into the future brings new possibilities for many 'classic' scaling problems. Complex systems and atomic displacements to cracks are but two examples. However, even with increasing computational speeds, the development of theory, numerical representations, algorithms, and efficient implementation are required for substantial success, exhibiting the crucial role that SciDAC will play.

Film cooling for a closed loop cooled airfoil

DOEpatents

Burdgick, Steven Sebastian; Yu, Yufeng Phillip; Itzel, Gary Michael

2003-01-01

Turbine stator vane segments have radially inner and outer walls with vanes extending therebetween. The inner and outer walls are compartmentalized and have impingement plates. Steam flowing into the outer wall plenum passes through the impingement plate for impingement cooling of the outer wall upper surface. The spent impingement steam flows into cavities of the vane having inserts for impingement cooling the walls of the vane. The steam passes into the inner wall and through the impingement plate for impingement cooling of the inner wall surface and for return through return cavities having inserts for impingement cooling of the vane surfaces. At least one film cooling hole is defined through a wall of at least one of the cavities for flow communication between an interior of the cavity and an exterior of the vane. The film cooling hole(s) are defined adjacent a potential low LCF life region, so that cooling medium that bleeds out through the film cooling hole(s) reduces a thermal gradient in a vicinity thereof, thereby the increase the LCF life of that region.

Low strain, long life creep fatigue of AF2-1DA and INCO 718

NASA Technical Reports Server (NTRS)

Thakker, A. B.; Cowles, B. A.

1983-01-01

Two aircraft turbine disk alloys, GATORIZED AF2-DA and INCO 718 were evaluated for their low strain long life creep-fatigue behavior. Static (tensile and creep rupture) and cyclic properties of both alloys were characterized. The cntrolled strain LCF tests were conducted at 760 C (1400 F) and 649 C (1200 F) for AF2-1DA and INCO 718, respectively. Hold times were varied for tensile, compressive and tensile/compressive strain dwell (relaxation) tests. Stress (creep) hold behavior of AF2-1DA was also evaluated. Generally, INCO 718 exhibited more pronounced reduction in cyclic life due to hold than AF2-1DA. The percent reduction in life for both alloys for strain dwell tests was greater at low strain ranges (longer life regime). Changing hold time from 0 to 0.5, 2.0 and 15.0 min. resulted in corresponding reductions in life. The continuous cycle and cyclic/dwell initiation failure mechanism was predominantly transgranular for AF2-1DA and intergranular for INCO 718.

Thrust chamber material technology program

NASA Technical Reports Server (NTRS)

Andrus, J. S.; Bordeau, R. G.

1989-01-01

This report covers work performed at Pratt & Whitney on development of copper-based materials for long-life, reusable, regeneratively cooled rocket engine thrust chambers. The program approached the goal of enhanced cyclic life through the application of rapid solidification to alloy development, to introduce fine dispersions to strengthen and stabilize the alloys at elevated temperatures. After screening of alloy systems, copper-based alloys containing Cr, Co, Hf, Ag, Ti, and Zr were processed by rapid-solidification atomization in bulk quantities. Those bulk alloys showing the most promise were characterized by tensile testing, thermal conductivity testing, and elevated-temperature, low-cycle fatigue (LFC) testing. Characterization indicated that Cu- 1.1 percent Hf exhibited the greatest potential as an improved-life thrust chamber material, exhibiting LCF life about four times that of NASA-Z. Other alloys (Cu- 0.6 percent Zr, and Cu- 0.6 percent Zr- 1.0 percent Cr) exhibited promise for use in this application, but needed more development work to balance properties.

Bone char effects on soil: sequential fractionations and XANES spectroscopy

NASA Astrophysics Data System (ADS)

Morshedizad, Mohsen; Panten, Kerstin; Klysubun, Wantana; Leinweber, Peter

2018-01-01

The acceptability of novel bone char fertilizers depends on their P release, but reactions at bone char surfaces and impacts on soil P speciation are insufficiently known. By using sequential fractionation and synchrotron-based X-ray absorption near-edge structure (XANES) spectroscopy we investigated whether and how the chemical composition of bone char particles has been altered in soil and has consequently affected the P speciation of amended soils. Therefore, two different kinds of bone char particles (BC produced by the pyrolysis of degreased animal bone chips at 800 °C and BCplus, a BC enriched with reduced sulfur compounds) were manually separated from the soil at the end of two different experiments: incubation leaching and ryegrass cultivation. Sequential P fractionation of amended soils showed P enrichment in all fractions compared to the control. The most P increase between all treatments significantly occurred in the NaOH-P and resin-P fractions in response to BCplus application in both incubation-leaching and ryegrass cultivation experiments. This increase in the readily available P fraction in BCplus-treated soils was confirmed by linear combination fitting (LCF) analysis on P K-edge XANES spectra of BC particles and amended soils. The proportion of Ca hydroxyapatite decreased, whereas the proportion of CaHPO4 increased in BCplus particles after amended soils had been incubated and leached and cropped by ryegrass. Based on P XANES speciation as determined by LCF analysis, the proportion of inorganic Ca(H2PO4)2 increased in amended soils after BCplus application. These results indicate that soil amendment with BCplus particles leads to elevated P concentration and maintains more soluble P species than BC particles even after 230 days of ryegrass cultivation.

Development of fracture mechanics data for two hydrazine APU turbine wheel materials

NASA Technical Reports Server (NTRS)

Curbishley, G.

1975-01-01

The effects of high temperature, high pressure ammonia were measured on the fracture mechanics and fatigue properties of Astroloy and Rene' 41 turbine wheel materials. Also, the influence of protective coatings on these properties was investigated. Specimens of forged bar stock were subjected to LCF and HCF tests at 950 K (1250 F) and 3.4 MN/sq m (500 psig) pressure, in ammonia containing about 1.5 percent H2O. Aluminized samples (Chromizing Company's Al-870) and gold plated test bars were compared with uncoated specimens. Comparison tests were also run in air at 950 K (1250 F), but at ambient pressures. K sub IE and K sub TH were determined on surface flawed specimens in both the air and ammonia in both uncoated and gold plated conditions. Gold plated specimens exhibited better properties than uncoated samples, and aluminized test bars generally had lower properties. The fatigue properties of specimens tested in ammonia were higher than those tested in air, yet the K sub TH values of ammonia tested samples were lower than those tested in air. However, insufficient specimens were tested to develop significant design data.

Analysis of Deformation Substructures in a Notched LCF Sample Under Dwell Condition in a Ni-Based Superalloy (PREPRINT)

DTIC Science & Technology

2012-08-01

interior, and carbides and borides at the grain boundaries. Blocky carbide particles can also be seen in the grain interior (Figure 1b). The borides ...can be seen distributed (b) higher magnification image of a typical grain boundary decorated with carbide and boride particles. Bi-modal distribution

Biocidal additives for lubricating/cooling fluids

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

Morozova, L.P.; Klyavlina, E.A.; Lebedev, E.V.

1984-03-01

This article reports on the synthesis of new biocidal products for the protection of water emulsions of lubricating/cooling fluids (LCFs) against microbiological damage. The new biocides are based on compounds belonging to the classes of oxazolidines and oxazines, and also compounds of these classes but activated by nitro derivatives of aromatic hydrocarbons. Results are presented from evaluations of the biocidal activity of the new products with respect to aerobes, anaerobes, and fungi growing in a 3% emulsion of the widely used LCF Ukrinol-1. The comparative evaluation was based on the optimal biocidal concentration corresponding to the smallest quantity of addedmore » biocide to give maximum suppression of the microorganisms in a minimum time, and with the longest period of effectiveness. The lubricating properties of the biocides were evaluated in an emulsion of the Ukrinol-1 LCF is a four-ball tester. It is concluded that the developed biocides are homogeneous, transparent liquids with a specific odor and can be considered as nontoxic to man; they mix readily with components used in formulating LCFs and detergents (sulfonates, oxyethylated alcohols, phenols, polyglycols, fatty acid soaps, etc.). They are readily soluble in water and in oils. Includes 3 tables.« less

Low cycle fatigue of PM/HIP astroloy

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

Choe, S.J.; Stoloff, N.S.; Duquette, D.J.

Low cycle fatigue and creep-fatigue-environment interactions of PM/HIP Astrology were studied at 650 C and 725 C. Total strain range was varied from 1.5% to 2.7% at a frequency of 0.3Hz. Creep-fatigue tests were performed with 2 min. or 5 min. tensile hold times. All tests were run in high purity argon in an attempt to minimize environmental effects. Employing a tensile hold was more damaging than raising temperature by 75 C. Slopes of Coffin-Manson plots were nearly independent of temperature and hold time. Raising temperature from 650 C to 725 C did not change the transgranular (TG) crack propagationmore » mode, whereas employing hold times caused TG+IG propagation. All samples displayed multiple fracture origins associated with inclusions located at the specimen surface; pre-existing pores did not affect fatigue crack initiation. Examination of secondary cracks showed no apparent creep damage. Oxidation in high purity argon appeared to be the major factor in LCF life degradation due to hold times.« less

Life prediction and constitutive models for engine hot section anisotropic materials program

NASA Technical Reports Server (NTRS)

Swanson, G. A.; Linask, I.; Nissley, D. M.; Norris, P. P.; Meyer, T. G.; Walker, K. P.

1986-01-01

This report presents the results of the first year of a program designed to develop life prediction and constitutive models for two coated single crystal alloys used in gas turbine airfoils. The two alloys are PWA 1480 and Alloy 185. The two oxidation resistant coatings are PWA 273, an aluminide coating, and PWA 286, an overlay NiCoCrAlY coating. To obtain constitutive and/or fatigue data, tests were conducted on coated and uncoated PWA 1480 specimens tensilely loaded in the 100 , 110 , 111 , and 123 directions. A literature survey of constitutive models was completed for both single crystal alloys and metallic coating materials; candidate models were selected. One constitutive model under consideration for single crystal alloys applies Walker's micromechanical viscoplastic formulation to all slip systems participating in the single crystal deformation. The constitutive models for the overlay coating correlate the viscoplastic data well. For the aluminide coating, a unique test method is under development. LCF and TMF tests are underway. The two coatings caused a significant drop in fatigue life, and each produced a much different failure mechanism.

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

Li, Winnie; Cho, Young-Bin; Department of Radiation Oncology, University of Toronto, Toronto, Ontario

Purpose: The present study used cone beam computed tomography (CBCT) to measure the inter- and intrafraction uncertainties for intracranial stereotactic radiosurgery (SRS) using the Leksell Gamma Knife (GK). Methods and Materials: Using a novel CBCT system adapted to the GK radiosurgery treatment unit, CBCT images were acquired immediately before and after treatment for each treatment session within the context of a research ethics board–approved prospective clinical trial. Patients were immobilized in the Leksell coordinate frame (LCF) for both volumetric CBCT imaging and GK-SRS delivery. The relative displacement of the patient's skull to the stereotactic reference (interfraction motion) was measured formore » each CBCT scan. Differences between the pre- and post-treatment CBCT scans were used to determine the intrafraction motion. Results: We analyzed 20 pre- and 17 post-treatment CBCT scans in 20 LCF patients treated with SRS. The mean translational pretreatment setup error ± standard deviation in the left-right, anteroposterior, and craniocaudal directions was −0.19 ± 0.32, 0.06 ± 0.27, and −0.23 ± 0.2 mm, with a maximum of −0.74, −0.53, and −0.68 mm, respectively. After an average time between the pre- and post-treatment CBCT scans of 82 minutes (range 27-170), the mean intrafraction error ± standard deviation for the LCF was −0.03 ± 0.05, −0.03 ± 0.18, and −0.03 ± 0.12 mm in the left-right, anteroposterior, and craniocaudual direction, respectively. Conclusions: Using CBCT on a prototype image guided GK Perfexion unit, we were able to measure the inter- and intrafraction positional changes for GK-SRS using the invasive frame. In the era of image guided radiation therapy, the use of CBCT image guidance for both frame- and non–frame-based immobilization systems could serve as a useful quality assurance tool. Our preliminary measurements can guide the application of achievable thresholds for inter- and intrafraction discrepancy when moving to a frameless approach.« less

The Use of Cone Beam Computed Tomography for Image Guided Gamma Knife Stereotactic Radiosurgery: Initial Clinical Evaluation.

PubMed

Li, Winnie; Cho, Young-Bin; Ansell, Steve; Laperriere, Normand; Ménard, Cynthia; Millar, Barbara-Ann; Zadeh, Gelareh; Kongkham, Paul; Bernstein, Mark; Jaffray, David A; Chung, Caroline

2016-09-01

The present study used cone beam computed tomography (CBCT) to measure the inter- and intrafraction uncertainties for intracranial stereotactic radiosurgery (SRS) using the Leksell Gamma Knife (GK). Using a novel CBCT system adapted to the GK radiosurgery treatment unit, CBCT images were acquired immediately before and after treatment for each treatment session within the context of a research ethics board-approved prospective clinical trial. Patients were immobilized in the Leksell coordinate frame (LCF) for both volumetric CBCT imaging and GK-SRS delivery. The relative displacement of the patient's skull to the stereotactic reference (interfraction motion) was measured for each CBCT scan. Differences between the pre- and post-treatment CBCT scans were used to determine the intrafraction motion. We analyzed 20 pre- and 17 post-treatment CBCT scans in 20 LCF patients treated with SRS. The mean translational pretreatment setup error ± standard deviation in the left-right, anteroposterior, and craniocaudal directions was -0.19 ± 0.32, 0.06 ± 0.27, and -0.23 ± 0.2 mm, with a maximum of -0.74, -0.53, and -0.68 mm, respectively. After an average time between the pre- and post-treatment CBCT scans of 82 minutes (range 27-170), the mean intrafraction error ± standard deviation for the LCF was -0.03 ± 0.05, -0.03 ± 0.18, and -0.03 ± 0.12 mm in the left-right, anteroposterior, and craniocaudual direction, respectively. Using CBCT on a prototype image guided GK Perfexion unit, we were able to measure the inter- and intrafraction positional changes for GK-SRS using the invasive frame. In the era of image guided radiation therapy, the use of CBCT image guidance for both frame- and non-frame-based immobilization systems could serve as a useful quality assurance tool. Our preliminary measurements can guide the application of achievable thresholds for inter- and intrafraction discrepancy when moving to a frameless approach. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Copper Nanoparticle Induced Cytotoxicity to Nitrifying Bacteria ...

EPA Pesticide Factsheets

With the inclusion of engineered nanomaterials in industrial processes and consumer products, wastewater treatments plants (WWTPs) will serve as a major sink for these emerging contaminants. Previous research has demonstrated that nanomaterials are potentially toxic to microbial communities utilized in biological wastewater treatment (BWT). Copper-based nanoparticles (CuNPs) are of particular interest based on their increasing use in wood treatment, paints, household products, coatings, and byproducts of semiconductor manufacturing. A critical step in BWT is nutrient removal via denitrification. This study examined the potential toxicity of bare and polyvinylpyrrolidone (PVP) coated CuO, and Cu2O nanoparticles, as well as Cu ions to microbial communities responsible for nitrogen removal in BWT. Inhibition was inferred from changes to the specific oxygen uptake rate (sOUR) in the absence and presence of Cu ions and CuNPs. X-ray absorption fine structure spectroscopy, with Linear Combination Fitting (LCF), was utilized to track changes to Cu speciation throughout exposure. Results indicate that the dissolution of Cu ions from CuNPs drive microbial inhibition. The presence of a PVP coating on CuNPs has little effect on inhibition. LCF fitting of the biomass combined with metal partitioning analysis supports the current hypothesis that Cu-induced cytotoxicity is primarily caused by reactive oxygen species formed from ionic Cu in solution via catalytic reaction inter

Development of a novel dry powder inhalation formulation for the delivery of rivastigmine hydrogen tartrate.

PubMed

Simon, Alice; Amaro, Maria Inês; Cabral, Lucio Mendes; Healy, Anne Marie; de Sousa, Valeria Pereira

2016-03-30

The purpose of this study was to prepare engineered particles of rivastigmine hydrogen tartrate (RHT) and to characterize the physicochemical and aerodynamic properties, in comparison to a lactose carrier formulation (LCF). Microparticles were prepared from ethanol/water solutions containing RHT with and without the incorporation of L-leucine (Leu), using a spray dryer. Dry powder inhaler formulations prepared were characterized by scanning electron microscopy, powder X-ray diffraction, laser diffraction particle sizing, ATR-FTIR, differential scanning calorimetry, bulk and tapped density, dynamic vapour sorption and in vitro aerosol deposition behaviour using a next generation impactor. The smooth-surfaced spherical morphology of the spray dried microparticles was altered by adding Leu, resulting in particles becoming increasingly wrinkled with increasing Leu. Powders presented low densities. The glass transition temperature was sufficiently high (>90 °C) to suggest good stability at room temperature. As Leu content increased, spray dried powders presented lower residual solvent content, lower particle size, higher fine particle fraction (FPF<5 μm), and lower mass median aerodynamic diameter (MMAD). The LCF showed a lower FPF and higher MMAD, relative to the spray dried formulations containing more than 10% Leu. Spray dried RHT powders presented better aerodynamic properties, constituting a potential drug delivery system for oral inhalation. Copyright © 2016. Published by Elsevier B.V.

Use of X-Ray Absorption Spectroscopy (XAS) to Speciate Manganese in Airborne Particulate Matter from 5 Counties Across the US

PubMed Central

Datta, Saugata; Rule, Ana M; Mihalic, Jana N; Chillrud, Steve N; Bostick, Benjamin C.; Ramos-Bonilla, Juan P; Han, Inkyu; Polyak, Lisa M; Geyh, Alison S; Breysse, Patrick N

2012-01-01

The purpose of this study is to characterize manganese oxidation states and speciation in airborne particulate matter (PM), and describe how these potentially important determinants of PM toxicity vary by location. Ambient PM samples were collected from five counties across the US using a high volume sequential cyclone system that collects PM in dry bulk form segregated into “coarse” and “fine” size fractions. The fine fraction was analyzed for this study. Analyses included total Mn using ICP-MS, and characterization of oxidation states and speciation using X-ray Absorption Spectroscopy (XAS). XAS spectra of all samples and ten standard compounds of Mn were obtained at the National Synchrotron Light Source. XAS data was analyzed using Linear Combination Fitting (LCF). Results of the LCF analysis describe differences in composition between samples. Mn(II) acetate and Mn(II) oxide are present in all samples, while Mn(II) carbonate and Mn(IV) oxide are absent. To the best of our knowledge, this is the first paper to characterize Mn composition of ambient PM and examine differences between urban sites in the US. Differences in oxidation state and composition indicate regional variations in sources and atmospheric chemistry that may help explain differences in health effects identified in epidemiological studies. PMID:22309075

Cu-Cr-Nb-Zr Alloy for Rocket Engines and Other High-Heat- Flux Applications

NASA Technical Reports Server (NTRS)

Ellis, David L.

2013-01-01

Rocket-engine main combustion chamber liners are used to contain the burning of fuel and oxidizer and provide a stream of high-velocity gas for propulsion. The liners in engines such as the Space Shuttle Main Engine are regeneratively cooled by flowing fuel, e.g., cryogenic hydrogen, through cooling channels in the back side of the liner. The heat gained by the liner from the flame and compression of the gas in the throat section is transferred to the fuel by the liner. As a result, the liner must either have a very high thermal conductivity or a very high operating temperature. In addition to the large heat flux (>10 MW/sq m), the liners experience a very large thermal gradient, typically more than 500 C over 1 mm. The gradient produces thermally induced stresses and strains that cause low cycle fatigue (LCF). Typically, a liner will experience a strain differential in excess of 1% between the cooling channel and the hot wall. Each time the engine is fired, the liner undergoes an LCF cycle. The number of cycles can be as few as one for an expendable booster engine, to as many as several thousand for a reusable launch vehicle or reaction control system. Finally, the liners undergo creep and a form of mechanical degradation called thermal ratcheting that results in the bowing out of the cooling channel into the combustion chamber, and eventual failure of the liner. GRCop-84, a Cu-Cr-Nb alloy, is generally recognized as the best liner material available at the time of this reporting. The alloy consists of 14% Cr2Nb precipitates in a pure copper matrix. Through experimental work, it has been established that the Zr will not participate in the formation of Laves phase precipitates with Cr and Nb, but will instead react with Cu to form the desired Cu-Zr compounds. It is believed that significant improvements in the mechanical properties of GRCop-84 will be realized by adding Zr. The innovation is a Cu-Cr-Nb-Zr alloy covering the composition range of 0.8 to 8.1 weight percent Cr, 0.7 to 7.2 weight percent Nb, 0.1 to 1.5 weight percent Zr, and balance Cu. The alloy combines two known strengthening mechanisms - dispersion strengthening by Cr2Nb precipitates (GRCop-84), and precipitation strengthening by CuxZr (AMZIRC) - to produce a synergistic increase in the capabilities of the alloy with the goal of achieving properties greater than either of the methods could achieve alone. The anticipated advantages of the alloy are higher strength at temperatures up to 700 C, improved creep strength, and significantly higher LCF lives relative to GRCop-84. The thermal expansion, thermal conductivity, and processing of the alloy are anticipated to remain largely unchanged relative to GRCop-84.

Greenhouse gas emissions from rice, peanut and millet farms in peninsular India: Effects of water and nitrogen management

NASA Astrophysics Data System (ADS)

Kritee, K.; Tiwari, R.; Nair, D.; Loecke, T. D.; Adhya, T. K.; Rudek, J.; Ahuja, R.; Hamburg, S.

2013-12-01

At Environmental Defense Fund (EDF), we recognize that any intervention to mitigate greenhouse gas (GHG) emissions should meet the interests of small scale farmers and low-carbon farming (LCF) is an integral component of our work on international climate. As a part of our Emissions Measurement and Methodology Development (EMD) Project, a joint undertaking with Indian NGO partners of the Fair Climate Network (FCN), five GHG measurement laboratories were set up across three states in peninsular (south) India. These labs represent different agro-ecological zones within the dryland agriculture belt in South India for which no reliable datasets on GHG emission have been available. Our approach for collecting gas samples was based on the Gracenet protocol. Sampling for nitrous oxide and methane emissions were made on approximately 50% of the total number of days in a growing season and once a week during fallow periods. In order to capture the peak emissions of nitrous oxide, samples were collected for 3-4 consecutive days after critical events like tillage, weeding, fertilization, and rainfall/irrigation. The research team collected field data at the time of sampling (temperature of the soil, water and air; and water levels). We also recorded parameters (e.g. water, fertilizer, labor and energy use; and yields) which were necessary for calculating farm profitability. Our data from 2012-2013 suggest that, for peninsular India, low-carbon rice cultivation techniques offer very large emission reduction potential (2-5 metric tons CO2e per acre per year), with smaller reductions from peanut and millet (0.15-0.5 metric ton CO2e per acre per season). The Tier 1 IPCC emissions factors 1) grossly underestimate both the amount of nitrous oxide emission from conventional rice cultivation practices, and the extent to which it can be reduced through better fertilizer management and 2) overestimate the methane emission reduction possible due to water management for rice paddies by a small but significant amount. It is crucial to customize fertilizer and water management to each agro-ecological zone such that net GHG emission reduction is maximized. Further comprehensive measurements over next 2-3 growing seasons will make Indian GHG emissions calculations from peninsular region more accurate. Even more importantly, these measurements will enable the region to more effectively reduce emissions from rice cultivation. Our preliminary assessments also show that LCF practices also have the potential to decrease water use by 10-30%, reduce total nitrogen loading in local water bodies by 20-40%, and improve long term soil health by optimizing organic matter and increasing water-holding capacity. Thus, we demonstrate immediate benefits of LCF practices in reducing input costs as well as lay the path for methodology development for better quantification of GHG emission reductions. Monetization of these reductions can provide an additional income stream to small scale farms, thereby helping incentivize adoption of LCF practices. The central payoff is a 'triple win' for society: increased long-term food security (including through enhanced yields), rural economic development (through improved farm profitability and adaptation to climate change), and lower environmental impacts (including lower GHG emissions).

Lift cruise fan V/STOL aircraft conceptual design study T-39 modification. Volume 1: Technical report

NASA Technical Reports Server (NTRS)

Elliott, D. W.

1976-01-01

The conversion of two T-39 aircraft into lift cruise fan research and technology vehicles is discussed. The concept is based upon modifying the T-39A (NA265-40) Sabreliner airframe into a V/STOL configuration by incorporating two LCF-459 lift cruise fans and three YJ-97 gas generators. The propulsion concept provides the thrust for horizontal flight or lift for vertical flight by deflection of bifurcated nozzles while maintaining engine out safety throughout the flight envelope. The configuration meets all the study requirements specified for the design with control powers in VTOL and conversion in excess of the requirement making it an excellent vehicle for research and development. The study report consists of two volumes; Volume 1 (Reference a) contains background data detailed description and technical substantiation of the aircraft. Volume 2 includes cost data, scheduling and program planning not addressed in Volume 1.

Joint Services Electronics Program - JSEP. Research in Electronics.

DTIC Science & Technology

1985-04-30

5 6 7’ TIME (SEC) T5us 󈨇 5C .4 6. 3[ 13 s ua -5 os 4 .7 4 C T7 r 4 9 Torr SU8 6200C P - 1 𔄃 lcF To AS1 0 c- .9-S p 7 -9 . 4 co - * 9 ’V...Lightwave Technology. Other studies have involved measuring polymer film waveguides using a leaky waveguide method, published by Ding and Garmire

Estimation of Axial Fretting Fatigue Life at Elevated Temperatures Using Critical Distance Theory

NASA Astrophysics Data System (ADS)

Majzoobi, G. H.; Azhdarzadeh, P.

Fretting fatigue life is traditionally estimated by experiment. The objective of this work is to introduce a special approach for estimation of axial fretting fatigue life at elevated temperatures from plain fatigue test based on the critical distance theory. The method uses Fatemi-Socie parameter as a multiaxial criterion to compute the stress multiaxiality on focus path. This method considers only elastic behavior for materials, and two characteristic diagrams are obtained from plain fatigue tests on two U-shaped and V-shaped notched specimens. The results showed reasonable agreement between the predictions by the proposed method and the experiments for ambient temperature. For elevated temperatures, the results indicated that the predicted fretting fatigue life was considerably overestimated in the low cycle fatigue (LCF) regime and underestimated in the high cycle fatigue (HCF) region with respect to experimental measurements. The reason for such discrepancy is believed to be due to the complex behavior of AL 7075-T6, which exhibits at elevated temperatures because of the problems such as aging, oxidation and reduction of strength.

Feeding a high-concentrate corn straw diet increased the release of endotoxin in the rumen and pro-inflammatory cytokines in the mammary gland of dairy cows.

PubMed

Zhou, Jun; Dong, Guozhong; Ao, Changjin; Zhang, Sen; Qiu, Min; Wang, Xi; Wu, Yongxia; Erdene, Khas; Jin, Lu; Lei, Chunlong; Zhang, Zhu

2014-08-01

The objective of this study was to investigate the effects of feeding a high-concentrate corn straw diet on the release of endotoxin in the rumen and the changes of pro-inflammatory cytokines in the mammary gland of dairy cows in comparison with a low-concentrate corn straw diet and a low-concentrate mixed forage diet. Thirty second-parity Chinese Holstein cows in mid-lactation with a body condition score of 2.86 ± 0.29, weighing 543 ± 57 kg and producing 24.32 ± 3.86 kg milk per day were randomly assigned to 1 of the 3 diets (n = 10 per treatment): 1) low-concentrate mixed forage diet (LCF) with a concentrate to roughage ratio of 46 : 54; 2) high-concentrate corn straw diet (HCS) with a concentrate to roughage ratio of 65 : 35; 3) low-concentrate corn straw diet (LCS) with the same concentrate to roughage ratio (46 : 54) as LCF. The experiment lasted 6 weeks, and samples were collected in the last week. Milk samples were analyzed for conventional components, rumen fluid samples were analyzed for pH and endotoxin, and mammary arterial and venous plasma samples were analyzed for concentrations of interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor alpha (TNF-α). Concentrations of endotoxin in rumen fluid and feces of cows fed HCS were significantly higher than those of cows fed LCS and LCF. Feeding HCS increased the release of IL-1β, IL-6 and IL-8 in the mammary gland compared with feeding LCS. Concentrations of cytokines (IL-1β and IL-8) in mammary venous plasma had a negative correlation with milk production efficiencies. Results indicated that the high-concentrate corn straw diet increased the concentrations of endotoxin in rumen fluid and feces. Furthermore, feeding the high-concentrate corn straw diet stimulated the mammary gland to release more pro-inflammatory cytokines. The results suggest that feeding a high-concentrate corn straw diet induce a higher pro-inflammatory response in the mammary gland and thus may partly decrease the milk production efficiencies in dairy cows.

Predictive Engineering Tools for Injection-molded Long-Carbon-Fiber Thermoplastic Composites - FY 2014 Third Quarterly Report

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

Nguyen, Ba Nghiep; Sanborn, Scott E.; Mathur, Raj N.

2014-08-15

This report describes the technical progresses made during the third quarter of FY 2014: 1) Autodesk introduced the options for fiber inlet condition to the 3D solver. These options are already available in the mid-plane/dual domain solver. 2) Autodesk improved the accuracy of 3D fiber orientation calculation around the gate. 3) Autodesk received consultant services from Prof. C.L. Tucker at the University of Illinois on the implementation of the reduced order model for fiber length, and discussed with Prof. Tucker the methods to reduce memory usage. 4) PlastiComp delivered to PNNL center-gated and edge-fan-gated 20-wt% to 30-wt% LCF/PP and LCF/PA66more » (7”x7”x1/8”) plaques molded by the in-line direct injection molding (D-LFT) process. 5) PlastiComp molded ASTM tensile, flexural and impact bars under the same D-LFT processing conditions used for plaques for Certification of Assessment and ascertaining the resultant mechanical properties. 6) Purdue developed a new polishing routine, utilizing the automated polishing machine, to reduce fiber damage during surface preparation. 7) Purdue used a marker-based watershed segmentation routine, in conjunction with a hysteresis thresholding technique, for fiber segmentation during fiber orientation measurement. 8) Purdue validated Purdue’s fiber orientation measurement method using the previous fiber orientation data obtained from the Leeds machine and manually measured data by the University of Illinois. 9) PNNL conducted ASMI mid-plane analyses for a 30wt% LCF/PP plaque and compared the predicted fiber orientations with the measured data provided by Purdue University at the selected locations on this plaque. 10) PNNL put together the DOE 2014 Annual Merit Review (AMR) presentation with the team and presented it at the AMR meetings on June 17, 2014. 11) PNNL built ASMI dual domain models for the Toyota complex part and commenced mold filling analyses of the complex part with different wall thicknesses in order to support part molding. 12) Toyota and Magna discussed with PNNL on tool modification for molding the complex part. Toyota sent the CAD files of the complex part to PNNL to build ASMI models of the part for mold filling analysis to provide guidance to tooling and part molding.« less

NASA/Navy lift/cruise fan cost reduction studies

NASA Technical Reports Server (NTRS)

1977-01-01

Cost reduction studies were performed for the LCF459 turbotip fan for application with the YJ97-GE-100 gas generator in a multimission V/STOL research and technology aircraft. A 20 percent cost reduction of the research configuration based on the original preliminary design was achieved. The trade studies performed and the results in the area of cost reduction and weight are covered. A fan configuration is defined for continuation of the program through the detailed design phase.

Next Generation 3D Mixed Mode Fracture Propagation Theory Including HCF-LCF Interaction (Preprint)

DTIC Science & Technology

2010-01-01

vectors. Depending on processing symmetries, the six principal fracture resistance values may not all be unique. If they are all equal, and l m=1...detail, see [26]. Table 1. Inco 718 Crack Kink angle Data Measured Kink Angles Spec No RI RII RIII KI+ KII+ KIII+ Mean Beq Primary Secondary In Phase 1...R. Ingraffea, “Interactive Finite-Element Analyses of Fracture Processes : An Integrated Approach”, Theoretical and Applied Fracture Mechanics, Vol

Fatigue of Ti-3A1-2.5V Alloy Tube and Rod

DTIC Science & Technology

2007-02-28

during cyclic straining of a 18% nickel maraging steel and attributed it to the presence of a crack. Skelton (reference 6) also attributed a hysteresis...growth, and fracture lives was also defined. The LCF behavior of the alloy tube and rod was investigated, examining the shape change of load...is weldable as the commercially pure grades and has excellent resistance to torsion and corrosion . Therefore, it is used principally as tubing in

A variable-mode stator consequent pole memory machine

NASA Astrophysics Data System (ADS)

Yang, Hui; Lyu, Shukang; Lin, Heyun; Zhu, Z. Q.

2018-05-01

In this paper, a variable-mode concept is proposed for the speed range extension of a stator-consequent-pole memory machine (SCPMM). An integrated permanent magnet (PM) and electrically excited control scheme is utilized to simplify the flux-weakening control instead of relatively complicated continuous PM magnetization control. Due to the nature of memory machine, the magnetization state of low coercive force (LCF) magnets can be easily changed by applying either a positive or negative current pulse. Therefore, the number of PM poles may be changed to satisfy the specific performance requirement under different speed ranges, i.e. the machine with all PM poles can offer high torque output while that with half PM poles provides wide constant power range. In addition, the SCPMM with non-magnetized PMs can be considered as a dual-three phase electrically excited reluctance machine, which can be fed by an open-winding based dual inverters that provide direct current (DC) bias excitation to further extend the speed range. The effectiveness of the proposed variable-mode operation for extending its operating region and improving the system reliability is verified by both finite element analysis (FEA) and experiments.

Elimination of Dual Slope from the Coffin Manson Relationship of Low-Cycle Fatigue in the Titanium Alloy Timetal 834, by Cold Rolling

NASA Astrophysics Data System (ADS)

Sai Srinadh, K. V.; Singh, Vakil

2007-08-01

Cold rolling of the titanium alloy Timetal 834 was found to cause marked enhancement in low-cycle fatigue (LCF) life at low strain amplitude and to eliminate bilinear behavior from the Coffin Manson (C-M) relationship. It was due to work hardening of surface grains of soft orientation and consequent increase in resistance of the material against crack initiation. The observed effect was not associated with texture.

Passive Imagery Navigation

DTIC Science & Technology

1980-12-15

FINAL TECHNICAL REPT, 15 SEP 78.15 DEC, 80. 15 DEC, 80, REPTNO* LMSC.D767313 CONTRACTF33615-78.-! o AFWAL.TR.81.1044 FC"MtUMENT IDENTIFICATION ...motion stereo. As the stereo subsystem was V LOCKHEED PALO ALTO RESEARCH LABORATORY LOCKNEID MISSILIS & SPACI COMPANY. INC A IU SIOIAIY OF 1OCKNID AINC 1A...section 4.4) vii LOCKHEED PALO ALTO RESEARCH LABORATORY LOCNIID MISSILIS & SPACI COMPA NY. INC A SUISU OIAEY OI F LCfI 1 AII C IAF CORPORAIION 0 Special

The Effect of Prior Exposures on the Notched Fatigue Behavior of Disk Superalloy ME3

NASA Technical Reports Server (NTRS)

Sudbrack, Chantal K.; Draper, Susan L.; Gorman, Timothy T.; Telesman, Jack; Gabb, Tim P.; Hull, David R.; Perea, Daniel E.; Schreiber, Daniel K.

2013-01-01

Environmental attack has the potential to limit turbine disk durability, particularly in next generation engines which will run hotter; there is a need to understand better oxidation at potential service conditions and develop models that link microstructure to fatigue response. More efficient gas turbine engine designs will require higher operating temperatures. Turbine disks are regarded as critical flight safety components; a failure is a serious hazard. Low cycle fatigue is an important design criteria for turbine disks. Powder metallurgy alloys, like ME3, have led to major improvements in temperature performance through refractory additions (e.g. Mo,W) at the expense of environmental resistance (Al, Cr). Service conditions for aerospace disks can produce major cycle periods extending from minutes to hours and days with total service times exceeding 1,000 hours in aerospace applications. Some of the effects of service can be captured by extended exposures at elevated temperature prior to LCF testing. Some details of the work presented here have been published.

Structural and biochemical characterization of the protease domain of the mosaic botulinum neurotoxin type HA.

PubMed

Lam, Kwok-Ho; Sikorra, Stefan; Weisemann, Jasmin; Maatsch, Hannah; Perry, Kay; Rummel, Andreas; Binz, Thomas; Jin, Rongsheng

2018-04-23

The extreme toxicity of botulinum neurotoxins (BoNTs) relies on their specific cleavage of SNARE proteins, which eventually leads to muscle paralysis. One newly identified mosaic toxin, BoNT/HA (aka H or FA), cleaves VAMP-2 at a unique position between residues L54 and E55, but the molecular basis underlying VAMP-2-recognition of BoNT/HA remains poorly characterized. Here, we report a ∼2.09 Å resolution crystal structure of the light chain protease domain of BoNT/HA (LC/HA). Structural comparison between LC/HA and LC of BoNT/F1 (LC/F1) reveals distinctive hydrophobic and electrostatic features near the active sites, which may explain their different VAMP-2 cleavage sites. When compared to BoNT/F5 that cleaves VAMP-2 at the same site as BoNT/HA, LC/HA displays higher affinity for VAMP-2, which could be caused by their different surface charge properties surrounding a VAMP-2 exosite-binding cleft. Furthermore, systematic mutagenesis studies on VAMP-2 and structural modeling demonstrate that residues R47 to K59 spanning the cleavage site in VAMP-2 may adopt a novel extended conformation when interacting with LC/HA and LC/F5. Taken together, our structure provides new insights into substrate-recognition of BoNT/HA and paves the way for rational design of small molecule or peptide inhibitors against LC/HA.

Real-time monitoring of acoustic linear and nonlinear behavior of titanium alloys during low-cycle fatigue and high-cycle fatigue

NASA Astrophysics Data System (ADS)

Frouin, Jerome; Sathish, Shamachary; Na, Jeong K.

2000-05-01

An in-situ technique to measure sound velocity, ultrasonic attenuation and acoustic nonlinear property has been developed for characterization and early detection of fatigue damage in aerospace materials. For this purpose we have developed a computer software and measurement technique including hardware for the automation of the measurement. New transducer holder and special grips are designed. The automation has allowed us to test the long-term stability of the electronics over a period of time and so proof of the linearity of the system. Real-time monitoring of the material nonlinearity has been performed on dog-bone specimens from zero fatigue all the way to the final fracture under low-cycle fatigue test condition (LCF) and high-cycle test condition (HCF). Real-time health monitoring of the material can greatly contribute to the understanding of material behavior under cyclic loading. Interpretation of the results show that correlation exist between the slope of the curve described by the material nonlinearity and the life of the component. This new methodology was developed with an objective to predict the initiation of fatigue microcracks, and to detect, in-situ fatigue crack initiation as well as to quantify early stages of fatigue damage.

Mechanisms of Exhaust Pollutants and Plume Formation in Continuous Combustion.

DTIC Science & Technology

1984-06-01

device. 4.1.3 Dilute Swirl Combustor (DSC) A swirl-stabilized geometry was developed to address the deficiencies observed with the swirl CBC geometry and...certain deficiencies were apparent in the ability of the model to predict experimental trends. For example: (1) The velocity profiles (Figure lOa) show that...25,000 Re - 50,000 HDF LA 1.1 0.55 Prediction 1.2 0.71 Flow Visualization 0.92 0.66 0 LCF LA 1.2 0.60 Prediction 1.3 0.70 5 J~55 -* - *7 2-- tK2

Antifungal Activity of Wickerhamomyces anomalus and Lactobacillus plantarum during Sourdough Fermentation: Identification of Novel Compounds and Long-Term Effect during Storage of Wheat Bread ▿

PubMed Central

Coda, Rossana; Cassone, Angela; Rizzello, Carlo G.; Nionelli, Luana; Cardinali, Gianluigi; Gobbetti, Marco

2011-01-01

This study aimed at investigating the antifungal activity of Wickerhamomyces anomalus and sourdough lactic acid bacteria to extend the shelf life of wheat flour bread. The antifungal activity was assayed by agar diffusion, growth rate inhibition, and conidial germination assays, using Penicillium roqueforti DPPMAF1 as the indicator fungus. Sourdough fermented by Lactobacillus plantarum 1A7 (S1A7) and dough fermented by W. anomalus LCF1695 (D1695) were selected and characterized. The water/salt-soluble extract of S1A7 was partially purified, and several novel antifungal peptides, encrypted into sequences of Oryza sativa proteins, were identified. The water/salt-soluble extract of D1695 contained ethanol and, especially, ethyl acetate as inhibitory compounds. As shown by growth inhibition assays, both water/salt-soluble extracts had a large inhibitory spectrum, with some differences, toward the most common fungi isolated from bakeries. Bread making at a pilot plant was carried out with S1A7, D1695, or a sourdough started with a combination of both strains (S1A7-1695). Slices of the bread manufactured with S1A7-1695 did not show contamination by fungi until 28 days of storage in polyethylene bags at room temperature, a level of protection comparable to that afforded by 0.3% (wt/wt) calcium propionate. The effect of sourdough fermentation with W. anomalus LCF1695 was also assessed based on rheology and sensory properties. PMID:21441340

The effect of microstructure, temperature, and hold-time on low-cycle fatigue of As HIP P/M Rene 95

NASA Technical Reports Server (NTRS)

Bashir, S.; Antolovich, S. D.

1984-01-01

The effects of microstructure, temperature, plastic strain range, and hold time on the low-cycle fatigue (LCF) life were studied for Rene 95, an important Ni base superalloy used in jet engine disks. It was shown that the life could be varied by approximately an order of magnitude at elevated temperatures by simple heat treatments. The life was largest for the microstructure that promoted the most homogeneous deformation mode. The results are explained using the concept of a synergistic interaction between the deformation mode and boundary oxidation.

The Spider Center Wide File System; From Concept to Reality

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

Shipman, Galen M; Dillow, David A; Oral, H Sarp

2009-01-01

The Leadership Computing Facility (LCF) at Oak Ridge National Laboratory (ORNL) has a diverse portfolio of computational resources ranging from a petascale XT4/XT5 simulation system (Jaguar) to numerous other systems supporting development, visualization, and data analytics. In order to support vastly different I/O needs of these systems Spider, a Lustre-based center wide file system was designed and deployed to provide over 240 GB/s of aggregate throughput with over 10 Petabytes of formatted capacity. A multi-stage InfiniBand network, dubbed as Scalable I/O Network (SION), with over 889 GB/s of bisectional bandwidth was deployed as part of Spider to provide connectivity tomore » our simulation, development, visualization, and other platforms. To our knowledge, while writing this paper, Spider is the largest and fastest POSIX-compliant parallel file system in production. This paper will detail the overall architecture of the Spider system, challenges in deploying and initial testings of a file system of this scale, and novel solutions to these challenges which offer key insights into file system design in the future.« less

Review of the Agard S&M panel evaluation program of the NASA-Lewis 'SRP' approach to high-temperature LCF life prediction. [Strainrange Partitioning for Low Cycle Fatigue

NASA Technical Reports Server (NTRS)

Hirschberg, M. H.

1978-01-01

Twenty laboratories in six countries participated in this program, each testing its own materials of interest under its own laboratory conditions. In this way the results obtained provided validation of the Strainrange Partitioning (SRP) method for a wide range of materials and insured maximum usefulness to each of the participating laboratories. The first, very necessary step in the evaluation of any life prediction approach - assessing the ability of the method to predict life of simple laboratory specimens subjected to complex loading, was thereby taken. The culmination of this program was the Specialists Meeting that was held in Aalborg, Denmark in April of 1978. At that meeting the various investigators shared their findings, thus providing the basis for an in-depth evaluation of the SRP method. While the results were variable from laboratory to laboratory, most investigators agreed that the SRP method was a significant step toward life prediction in the presence of high temperature and cyclic stresses.

Comparative estimation of inevitable endogenous ileal flow of amino acids in Pekin ducks under varying dietary or physiological conditions and their significance to nutritional requirements for amino acids.

PubMed

Akinde, D O

2017-10-01

In 2 experiments in Pekin ducks the inevitable endogenous ileal flow (IEIF) of AA was estimated at changing intake and source of crude fiber (CF) or soybean oil (SO) level. Also the roles of dry matter intake (DMI) and BW or age as well as the proportion of IEIF in the dietary requirement for AA were studied. In experiment 1 three basal CP (20, 60, or 100 g/kg) diets were formulated containing a low CF (LCF, 30 g/kg) or high (HCF, 80 g/kg) level; achieved with cellulose supplementation. All diets were similar in every other respect including having SO content of 40 g/kg. Four floor pens of eight 85-day-old ducks were randomly allocated to each diet. Similar diets were mixed in experiment 2 but corn cob meal replaced cellulose as the fiber source. A high SO (HSO) series was also formed by increasing the SO level from 40 g/kg in the basal series to 100 g/kg. Thus the LCF series was concurrently classified as low SO (LSO) series to control SO effect. Each of the eventual 9 diets were fed to 5 floor pens of ten 65-day-old ducks. Ileal AA flow was measured after a 5 day feeding period in both experiments. Linear regression was calculated between ileal flow and dietary intake of individual AA. The IEIF interpreted as the y-intercept of each linear function responded neither to elevated ingestion of each CF type nor to SO level. Age and DMI had no effect on IEIF computed in relation to BW, but wide discrepancies resulted when related to DMI. Overall IEIF of AA varied between 14.3 to 129.8 mg/kg BW d-1. These flows were established in model computations to account for 10 to 64% of the recommended intake of limiting AA. In conclusion the ileal inevitable flow is constant within the dietary/age conditions investigated. However it is modulated by feed intake and accounts for a significant portion of total amino acid requirement. © 2017 Poultry Science Association Inc.

Creep fatigue life prediction for engine hot section materials (isotropic)

NASA Technical Reports Server (NTRS)

Moreno, Vito; Nissley, David; Lin, Li-Sen Jim

1985-01-01

The first two years of a two-phase program aimed at improving the high temperature crack initiation life prediction technology for gas turbine hot section components are discussed. In Phase 1 (baseline) effort, low cycle fatigue (LCF) models, using a data base generated for a cast nickel base gas turbine hot section alloy (B1900+Hf), were evaluated for their ability to predict the crack initiation life for relevant creep-fatigue loading conditions and to define data required for determination of model constants. The variables included strain range and rate, mean strain, strain hold times and temperature. None of the models predicted all of the life trends within reasonable data requirements. A Cycle Damage Accumulation (CDA) was therefore developed which follows an exhaustion of material ductility approach. Material ductility is estimated based on observed similarities of deformation structure between fatigue, tensile and creep tests. The cycle damage function is based on total strain range, maximum stress and stress amplitude and includes both time independent and time dependent components. The CDA model accurately predicts all of the trends in creep-fatigue life with loading conditions. In addition, all of the CDA model constants are determinable from rapid cycle, fully reversed fatigue tests and monotonic tensile and/or creep data.

SOARCA Peach Bottom Atomic Power Station Long-Term Station Blackout Uncertainty Analysis: Convergence of the Uncertainty Results

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

Bixler, Nathan E.; Osborn, Douglas M.; Sallaberry, Cedric Jean-Marie

2014-02-01

This paper describes the convergence of MELCOR Accident Consequence Code System, Version 2 (MACCS2) probabilistic results of offsite consequences for the uncertainty analysis of the State-of-the-Art Reactor Consequence Analyses (SOARCA) unmitigated long-term station blackout scenario at the Peach Bottom Atomic Power Station. The consequence metrics evaluated are individual latent-cancer fatality (LCF) risk and individual early fatality risk. Consequence results are presented as conditional risk (i.e., assuming the accident occurs, risk per event) to individuals of the public as a result of the accident. In order to verify convergence for this uncertainty analysis, as recommended by the Nuclear Regulatory Commission’s Advisorymore » Committee on Reactor Safeguards, a ‘high’ source term from the original population of Monte Carlo runs has been selected to be used for: (1) a study of the distribution of consequence results stemming solely from epistemic uncertainty in the MACCS2 parameters (i.e., separating the effect from the source term uncertainty), and (2) a comparison between Simple Random Sampling (SRS) and Latin Hypercube Sampling (LHS) in order to validate the original results obtained with LHS. Three replicates (each using a different random seed) of size 1,000 each using LHS and another set of three replicates of size 1,000 using SRS are analyzed. The results show that the LCF risk results are well converged with either LHS or SRS sampling. The early fatality risk results are less well converged at radial distances beyond 2 miles, and this is expected due to the sparse data (predominance of “zero” results).« less

Occurrence, distribution and bioaccumulation behaviour of hydrophobic organic contaminants in a large-scale constructed wetland in Singapore.

PubMed

Wang, Qian; Kelly, Barry C

2017-09-01

This study involved a field-based investigation to assess the occurrence, distribution and bioaccumulation behaviour of hydrophobic organic contaminants in a large-scale constructed wetland. Samples of raw leachate, water and wetland plants, Typha angustifolia, were collected for chemical analysis. Target contaminants included polychlorinated biphenyls (PCBs), organochlorine pesticides (OCP), as well as several halogenated flame retardants (HFRs) and personal care products (triclosan and synthetic musks). In addition to PCBs and OCPs, synthetic musks, triclosan (TCS) and dechlorane plus stereoisomers (syn- and anti-DPs) were frequently detected. Root concentration factors (log RCF L/kg wet weight) of the various contaminants ranged between 3.0 and 7.9. Leaf concentration factors (log LCF L/kg wet weight) ranged between 2.4 and 8.2. syn- and anti-DPs exhibited the greatest RCF and LCF values. A strong linear relationship was observed between log RCF and octanol-water partition coefficient (log K OW ). Translocation factors (log TFs) were negatively correlated with log K OW . The results demonstrate that more hydrophobic compounds exhibit higher degrees of partitioning into plant roots and are less effectively transported from roots to plant leaves. Methyl triclosan (MTCS) and 2,8-dichlorodibenzo-p-dioxin (DCDD), TCS degradation products, exhibited relatively high concentrations in roots and leaves., highlighting the importance of degradation/biotransformation. The results further suggest that Typha angustifolia in this constructed wetland can aid the removal of hydrophobic organic contaminants present in this landfill leachate. The findings will aid future investigations regarding the fate and bioaccumulation of hydrophobic organic contaminants in constructed wetlands. Copyright © 2017 Elsevier Ltd. All rights reserved.

Postoperative Management of Multiple Primary Cancers Associated with Non-small Cell Lung Cancer.

PubMed

Shoji, Fumihiro; Yamazaki, Koji; Miura, Naoko; Katsura, Masakazu; Oku, Yuka; Takeo, Sadanori; Maehara, Yoshihiko

2018-06-01

Modern treatment for primary cancers has improved survival. Therefore, increased numbers of patients with multiple primary cancers (MPC) associated with lung cancer may be expected. The aim of the present study was to report MPC associated with lung cancer and discuss patients' characteristics and postoperative management. Overall, 973 consecutive patients who underwent surgery for non-small cell lung cancer (NSCLC) were retrospectively studied. NSCLC with MPC was observed in 148 patients (15.2%). MPC comprised 24 synchronous (2.5%) and 124 metachronous (12.7%) diseases. Of the 124 metachronous patients, NSCLC was detected before cancers were detected in other organs (lung cancer first (LCF)) in 25 (20.2%) patients and subsequently in other organs after treatment (other organs, primary cancer-first (OCF)) in 99 (79.8%) patients. MPC was significantly associated with advanced age (p<0.0001) and chronic obstructive pulmonary disease (COPD) (p=0.0040). The leading sites of MPC in patients with synchronous tumors and those with OCF were the digestive organs. In contrast, the leading site of MPC in patients with LCF was the lung. In the latter, at least two primary lung cancers were detected within 5 years as well as 5 years after surgery for the treatment of the first detected lung cancer, while primary cancers of other organs were detected within 5 years. Advanced age and COPD may represent a high-risk of MPCs. Therefore, we recommend careful follow-up to detect MPC in the lung as well as the digestive organs beyond 5 years after treatment of the first cancer. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Full Food Service Contract for Army Dining Facilities

DTIC Science & Technology

1982-01-01

I LB - — —- COP’JE *">ältfO tlA INSTANT VA 0/ 1.** ." CN I» ’v — —. 1 »M 1 it IB 5r ».!•. 4<j l.?n I.Ti .6) • e...1 i f*»n*j MfDI»"* T#BTAC SA’lCF tO-| 1| AFAISEC MM AND NOODLES II-1TI AA«FD •’’TATTf S (Q-441 SCuA f»FA« H-T *MCf O...degree F preheated oven for about 15 minutes or until cheese is melted. 8 Beef Noodle Soup (Dehydrated) Prepare in accordance with directions

NASA/Navy life/cruise fan preliminary design report

NASA Technical Reports Server (NTRS)

1975-01-01

Preliminary design studies were performed to define a turbotip lift/cruise fan propulsion system for a Navy multimission aircraft. The fan is driven by the exhausts of the YJ97-GE-100 turbojet or a 20 percent Growth J97 configuration as defined during the studies. The LCF459 fan configuration defined has a tip diameter of 1.50 meters (59.0 inches) and develops a design point thrust of 75,130 N (16,890 lbs) at a fan pressure ratio of 1.319. The fan has an estimated weight of 386 kg (850 lbs). Trade studies performed to define the selected configuration are described.

Effects of near infrared laser radiation associated with photoabsorbing cream in preventing white spot lesions around orthodontic brackets: an in vitro study.

PubMed

Lacerda, Ângela Sueli Soares Braga; Hanashiro, Fernando Seishim; de Sant'Anna, Giselle Rodrigues; Steagall Júnior, Washington; Barbosa, Patrícia Silva; de Souza-Zaroni, Wanessa Christine

2014-12-01

The present study aims to investigate the effect of a low-power infrared laser on the inhibition of bovine enamel demineralization around orthodontic brackets. Near infrared lasers have been suggested as alternative approaches because they may produce an increase in resistance to dental caries. Forty-eight blocks of enamel obtained from bovine incisor teeth were divided into six groups: Group 1 (control), without treatment; Group 2 (C), photoabsorbing cream; Group 3 (CF), photoabsorbing cream with fluoride; Group 4 (L), irradiation with low-level infrared laser (λ=830 nm) at an energy density of 4.47 J/cm2; Group 5 (L+C), photoabsorbing cream followed by low-level infrared laser irradiation; and Group 6 (L+CF), photoabsorbing cream with fluoride followed by low-level infrared laser irradiation. After these procedures, the enamel blocks received an assortment of orthodontic brackets and were then submitted to pH cycling to simulate a highly cariogenic challenge. The enamel surface demineralization around the orthodontic brackets, according to the different treatments, was quantified by fluorescence loss analysis by quantitative light-induced fluorescence (QLF). The fluorescence loss, expressed as ΔF (percentage of loss fluorescence), was statistically examined by analysis of variance and the Tukey test. The control group (-10.48±2.85) was statistically similar to Group C (-14.52±7.80), which presented the lowest values of ΔF when compared with Groups FC (-3.67±3.21), L (-2.79±1.68), CL (-1.05±0:50), and CFL (-0.60±0:43). However, Groups FC, L, CL, and CFL showed no statistically significant differences among them. It can be concluded that both the low-level infrared laser and photoabsorbing cream with fluoride were effective in inhibiting the development of caries in enamel around orthodontic brackets, even in situations of high cariogenic challenge.

Oxidation of Alumina-Forming MAX Phases in Turbine Environments

NASA Technical Reports Server (NTRS)

Smialek, James; Garg, Anita; Harder, Bryan; Nesbitt, James; Gabb, Timothy; Gray, SImon

2017-01-01

Protective coatings for high temperature turbine components are based on YSZ thermal barriers and oxidation resistant, alumina-forming NiAl or NiCoCrAlY bond coats. Ti2AlC and Cr2AlC MAX phases are thus of special interest because of good oxidation resistance and CTE that can match Al2O3 and YSZ. Their alumina scales grow according to cubic kinetics due to grain growth in the scale, with initial heating dominated by fast TiO2 growth. Protective cubic kinetics are also found in high pressure burner rig tests of MAXthal 211 Ti2AlC, but with reduced rates due to volatile TiO(OH)2 formation in water vapor. YSZ-coatings on bulk Ti2AlC exhibit remarkable durability up to 1300C in furnace tests and at least a 25x life advantage compared to superalloys. At another extreme, Cr2AlC is resistant to low temperature Na2SO4 hot corrosion and exhibits thermal cycling stability bonded to a superalloy disk material. Accordingly, sputtered Cr2AlC coatings on disk specimens prevented hot corrosion detriments on LCF. Breakaway oxidation (Ti2AlC), scale spallation (Cr2AlC), interdiffusion, and processing as coatings still present serious challenges. However the basic properties of MAX phases provide some unusual opportunities for use in high temperature turbines.

Simulated Bladed MMC Disk LCF Validation

NASA Technical Reports Server (NTRS)

Merrick, H. F.; Costen, M.

1998-01-01

The goal of this program was to evaluate the low cycle fatigue behavior of an SCS-6/Ti-6Al-4V sub-component under bi-axial loading conditions at 316 C(600 F). A simulated bladed TMC disk was designed having thirty four blades representing the number that would be used in Allied Signal's JTAGG II impeller. The outer diameter of the bladed ring was 254 mm (10.0 inch) and the inner diameter 114.3 mm (4.50 inch). The outer and inner diameter of the composite zone was 177.8 mm (7.00 inch) and 127.O mm(5.00 inch) respectively. Stress analysis showed that the fatigue life of the bladed composite ring would be about 12000 cycles for the test conditions applied. A modal analysis was conducted which showed that the blades would have sufficient life margin from dynamic excitation. The arbor design was the same as that employed in the spin-to burst test of NAS3-27027. A systematic stress analysis of each part making up the arbor was undertaken to assure the design would meet the low cycle fatigue requirements of the program. The Textron Systems grooved foil-fiber process was chosen to make the SCS-6/Ti-6Al-4V core ring based on the success they had in contract NAS3-27027. Fiber buckling, however, was observed at several locations in the first ring made which rendered it unsuitable for spin testing. The fiber buckling was attributed to cracking of the graphite tooling during the consolidation process. On this basis a second ring was made but it too contained fiber buckling defects. Analysis by Textron indicated that the fiber buckling was most likely due to poor placement of the SCS-6 fiber in the etched grooves of the Ti-6Al-4V foil. This was also a contributor to the defects in the first ring. Since there was little indication of control in the process to manufacture a quality ring a third attempt at making a ring was not undertaken.

Application of Single Crystal Failure Criteria: Theory and Turbine Blade Case Study

NASA Technical Reports Server (NTRS)

Sayyah, Tarek; Swanson, Gregory R.; Schonberg, W. P.

1999-01-01

The orientation of the single crystal material within a structural component is known to affect the strength and life of the part. The first stage blade of the High Pressure Fuel Turbopump (HPFTP)/ Alternative Turbopump Development (ATD), of the Space Shuttle Main Engine (SSME) was used to study the effects of secondary axis'orientation angles on the failure rate of the blade. A new failure criterion was developed based on normal and shear strains on the primary crystallographic planes. The criterion was verified using low cycle fatigue (LCF) specimen data and a finite element model of the test specimens. The criterion was then used to study ATD/HPFTP first stage blade failure events. A detailed ANSYS finite element model of the blade was used to calculate the failure parameter for the different crystallographic orientations. A total of 297 cases were run to cover a wide range of acceptable orientations within the blade. Those orientations are related to the base crystallographic coordinate system that was created in the ANSYS finite element model. Contour plots of the criterion as a function of orientation for the blade tip and attachment were obtained. Results of the analysis revealed a 40% increase in the failure parameter due to changing of the primary and secondary axes of material orientations. A comparison between failure criterion predictions and actual engine test data was then conducted. The engine test data comes from two ATD/HPFTP builds (units F3- 4B and F6-5D), which were ground tested on the SSME at the Stennis Space Center in Mississippi. Both units experienced cracking of the airfoil tips in multiple blades, but only a few cracks grew all the way across the wall of the hollow core airfoil.

Fatigue life prediction of liquid rocket engine combustor with subscale test verification

NASA Astrophysics Data System (ADS)

Sung, In-Kyung

Reusable rocket systems such as the Space Shuttle introduced a new era in propulsion system design for economic feasibility. Practical reusable systems require an order of magnitude increase in life. To achieve this improved methods are needed to assess failure mechanisms and to predict life cycles of rocket combustor. A general goal of the research was to demonstrate the use of subscale rocket combustor prototype in a cost-effective test program. Life limiting factors and metal behaviors under repeated loads were surveyed and reviewed. The life prediction theories are presented, with an emphasis on studies that used subscale test hardware for model validation. From this review, low cycle fatigue (LCF) and creep-fatigue interaction (ratcheting) were identified as the main life limiting factors of the combustor. Several life prediction methods such as conventional and advanced viscoplastic models were used to predict life cycle due to low cycle thermal stress, transient effects, and creep rupture damage. Creep-fatigue interaction and cyclic hardening were also investigated. A prediction method based on 2D beam theory was modified using 3D plate deformation theory to provide an extended prediction method. For experimental validation two small scale annular plug nozzle thrusters were designed, built and tested. The test article was composed of a water-cooled liner, plug annular nozzle and 200 psia precombustor that used decomposed hydrogen peroxide as the oxidizer and JP-8 as the fuel. The first combustor was tested cyclically at the Advanced Propellants and Combustion Laboratory at Purdue University. Testing was stopped after 140 cycles due to an unpredicted failure mechanism due to an increasing hot spot in the location where failure was predicted. A second combustor was designed to avoid the previous failure, however, it was over pressurized and deformed beyond repair during cold-flow test. The test results are discussed and compared to the analytical and numerical predictions. A detailed comparison was not performed, however, due to the lack of test data resulting from a failure of the test article. Some theoretical and experimental aspects such as fin effect and round corner were found to reduce the discrepancy between prediction and test results.

Microbial cell-free extracts as sources of enzyme activities to be used for enhancement flavor development of ewe milk cheese.

PubMed

Calasso, Maria; Mancini, Leonardo; Di Cagno, Raffaella; Cardinali, Gianluigi; Gobbetti, Marco

2015-09-01

Freeze-dried cell-free extracts (CFE) from Lactobacillus casei LC01, Weissella cibaria 1XF5, Hafnia alvei Moller ATCC 51815, and Debaryomyces hansenii LCF-558 were used as sources of enzyme activities for conditioning the ripening of ewe milk cheese. Compared with control cheese (CC), CFE did not affect the gross composition and the growth of the main microbial groups of the cheeses. As shown through urea-PAGE electrophoresis of the pH 4.6-soluble nitrogen fraction and the analysis of free AA, the secondary proteolysis of the cheeses with CFE added was markedly differed from that of the CC. Compared with CC, several enzyme activities were higher in the water-soluble extracts from cheeses made with CFE. In agreement, the levels of 49 volatile compounds significantly differentiated CC from the cheeses made with CFE. The level of some alcohols, ketones, sulfur compounds, and furans were the lowest in the CC, whereas most aldehydes were the highest. Each CFE seemed to affect a specific class of chemical compounds (e.g., the CFE from H. alvei ATCC 51815 mainly influenced the synthesis of sulfur compounds). Apart from the microbial source used, the cheeses with the addition of CFE showed higher score for acceptability than the control cheese. Cheese ripening was accelerated or conditioned using CFE as sources of tailored enzyme activities. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Next Generation Workload Management System For Big Data on Heterogeneous Distributed Computing

NASA Astrophysics Data System (ADS)

Klimentov, A.; Buncic, P.; De, K.; Jha, S.; Maeno, T.; Mount, R.; Nilsson, P.; Oleynik, D.; Panitkin, S.; Petrosyan, A.; Porter, R. J.; Read, K. F.; Vaniachine, A.; Wells, J. C.; Wenaus, T.

2015-05-01

The Large Hadron Collider (LHC), operating at the international CERN Laboratory in Geneva, Switzerland, is leading Big Data driven scientific explorations. Experiments at the LHC explore the fundamental nature of matter and the basic forces that shape our universe, and were recently credited for the discovery of a Higgs boson. ATLAS and ALICE are the largest collaborations ever assembled in the sciences and are at the forefront of research at the LHC. To address an unprecedented multi-petabyte data processing challenge, both experiments rely on a heterogeneous distributed computational infrastructure. The ATLAS experiment uses PanDA (Production and Data Analysis) Workload Management System (WMS) for managing the workflow for all data processing on hundreds of data centers. Through PanDA, ATLAS physicists see a single computing facility that enables rapid scientific breakthroughs for the experiment, even though the data centers are physically scattered all over the world. The scale is demonstrated by the following numbers: PanDA manages O(102) sites, O(105) cores, O(108) jobs per year, O(103) users, and ATLAS data volume is O(1017) bytes. In 2013 we started an ambitious program to expand PanDA to all available computing resources, including opportunistic use of commercial and academic clouds and Leadership Computing Facilities (LCF). The project titled ‘Next Generation Workload Management and Analysis System for Big Data’ (BigPanDA) is funded by DOE ASCR and HEP. Extending PanDA to clouds and LCF presents new challenges in managing heterogeneity and supporting workflow. The BigPanDA project is underway to setup and tailor PanDA at the Oak Ridge Leadership Computing Facility (OLCF) and at the National Research Center "Kurchatov Institute" together with ALICE distributed computing and ORNL computing professionals. Our approach to integration of HPC platforms at the OLCF and elsewhere is to reuse, as much as possible, existing components of the PanDA system. We will present our current accomplishments with running the PanDA WMS at OLCF and other supercomputers and demonstrate our ability to use PanDA as a portal independent of the computing facilities infrastructure for High Energy and Nuclear Physics as well as other data-intensive science applications.

Preliminary study of thermomechanical fatigue of polycrystalline MAR-M 200

NASA Technical Reports Server (NTRS)

Bill, R. C.; Verrilli, M. J.; Mcgaw, M. A.; Halford, G. R.

1984-01-01

Thermomechanical fatigue (TMF) experiments were conducted on polycrystalline MAR-M 200 over a cyclic temperature range of 500 to 1000 C. Inelastic strain ranges of 0.03 to 0.2 percent were imposed on the specimens. The TMF lives were found to be significantly shorter than isothermal low-cycle-fatigue (LCF) life at the maximum cycle temperature, and in-phase cycling was more damaging than out-of-phase cycling. Extensive crack tip oxidation appeared to play a role in promoting the severity of in-phase cycling. Carbide particle - matrix interface cracking was also observed after in-phase TMF cycling. The applicability of various life prediction models to the TMF results obtained was assessed. It was concluded that current life prediction models based on isothermal data as input must be modified to be applicable to the TMF results.

Linear Combination Fitting (LCF)-XANES analysis of As speciation in selected mine-impacted materials

EPA Pesticide Factsheets

This table provides sample identification labels and classification of sample type (tailings, calcinated, grey slime). For each sample, total arsenic and iron concentrations determined by acid digestion and ICP analysis are provided along with arsenic in-vitro bioaccessibility (As IVBA) values to estimate arsenic risk. Lastly, the table provides linear combination fitting results from synchrotron XANES analysis showing the distribution of arsenic speciation phases present in each sample along with fitting error (R-factor).This dataset is associated with the following publication:Ollson, C., E. Smith, K. Scheckel, A. Betts, and A. Juhasz. Assessment of arsenic speciation and bioaccessibility in mine-impacted materials. Diana Aga, Wonyong Choi, Andrew Daugulis, Gianluca Li Puma, Gerasimos Lyberatos, and Joo Hwa Tay JOURNAL OF HAZARDOUS MATERIALS. Elsevier Science Ltd, New York, NY, USA, 313: 130-137, (2016).

MOGO: Model-Oriented Global Optimization of Petascale Applications

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

Malony, Allen D.; Shende, Sameer S.

The MOGO project was initiated under in 2008 under the DOE Program Announcement for Software Development Tools for Improved Ease-of-Use on Petascale systems (LAB 08-19). The MOGO team consisted of Oak Ridge National Lab, Argonne National Lab, and the University of Oregon. The overall goal of MOGO was to attack petascale performance analysis by developing a general framework where empirical performance data could be efficiently and accurately compared with performance expectations at various levels of abstraction. This information could then be used to automatically identify and remediate performance problems. MOGO was be based on performance models derived from application knowledge,more » performance experiments, and symbolic analysis. MOGO was able to make reasonable impact on existing DOE applications and systems. New tools and techniques were developed, which, in turn, were used on important DOE applications on DOE LCF systems to show significant performance improvements.« less

Report on the formal specification and partial verification of the VIPER microprocessor

NASA Technical Reports Server (NTRS)

Brock, Bishop; Hunt, Warren A., Jr.

1991-01-01

The VIPER microprocessor chip is partitioned into four levels of abstractions. At the highest level, VIPER is described with decreasingly abstract sets of functions in LCF-LSM. At the lowest level are the gate-level models in proprietary CAD languages. The block-level and gate-level specifications are also given in the ELLA simulation language. Among VIPER's deficiencies are the fact that there is no notion of external events in the top-level specification, and it is impossible to use the top-level specifications to prove abstract properties of programs running on VIPER computers. There is no complete proof that the gate-level specifications implement the top-level specifications. Cohn's proof that the major-state machine correctly implements the top-level specifications has no formal connection with any of the other proof attempts. None of the latter address resetting the machine, memory timeout, forced error, or single step modes.

NASALIFE - Component Fatigue and Creep Life Prediction Program

NASA Technical Reports Server (NTRS)

Gyekenyesi, John Z.; Murthy, Pappu L. N.; Mital, Subodh K.

2014-01-01

NASALIFE is a life prediction program for propulsion system components made of ceramic matrix composites (CMC) under cyclic thermo-mechanical loading and creep rupture conditions. Although the primary focus was for CMC components, the underlying methodologies are equally applicable to other material systems as well. The program references empirical data for low cycle fatigue (LCF), creep rupture, and static material properties as part of the life prediction process. Multiaxial stresses are accommodated by Von Mises based methods and a Walker model is used to address mean stress effects. Varying loads are reduced by the Rainflow counting method or a peak counting type method. Lastly, damage due to cyclic loading and creep is combined with Minor's Rule to determine damage due to cyclic loading, damage due to creep, and the total damage per mission and the number of potential missions the component can provide before failure.

Next Generation Workload Management System For Big Data on Heterogeneous Distributed Computing

DOE PAGES

Klimentov, A.; Buncic, P.; De, K.; ...

2015-05-22

The Large Hadron Collider (LHC), operating at the international CERN Laboratory in Geneva, Switzerland, is leading Big Data driven scientific explorations. Experiments at the LHC explore the fundamental nature of matter and the basic forces that shape our universe, and were recently credited for the discovery of a Higgs boson. ATLAS and ALICE are the largest collaborations ever assembled in the sciences and are at the forefront of research at the LHC. To address an unprecedented multi-petabyte data processing challenge, both experiments rely on a heterogeneous distributed computational infrastructure. The ATLAS experiment uses PanDA (Production and Data Analysis) Workload Managementmore » System (WMS) for managing the workflow for all data processing on hundreds of data centers. Through PanDA, ATLAS physicists see a single computing facility that enables rapid scientific breakthroughs for the experiment, even though the data centers are physically scattered all over the world. The scale is demonstrated by the following numbers: PanDA manages O(10 2) sites, O(10 5) cores, O(10 8) jobs per year, O(10 3) users, and ATLAS data volume is O(10 17) bytes. In 2013 we started an ambitious program to expand PanDA to all available computing resources, including opportunistic use of commercial and academic clouds and Leadership Computing Facilities (LCF). The project titled 'Next Generation Workload Management and Analysis System for Big Data' (BigPanDA) is funded by DOE ASCR and HEP. Extending PanDA to clouds and LCF presents new challenges in managing heterogeneity and supporting workflow. The BigPanDA project is underway to setup and tailor PanDA at the Oak Ridge Leadership Computing Facility (OLCF) and at the National Research Center "Kurchatov Institute" together with ALICE distributed computing and ORNL computing professionals. Our approach to integration of HPC platforms at the OLCF and elsewhere is to reuse, as much as possible, existing components of the PanDA system. Finally, we will present our current accomplishments with running the PanDA WMS at OLCF and other supercomputers and demonstrate our ability to use PanDA as a portal independent of the computing facilities infrastructure for High Energy and Nuclear Physics as well as other data-intensive science applications.« less

Change in Localizations of Arsenic in Rice Grains After Cooking with High Arsenic Waters - µXRF and XANES studies

NASA Astrophysics Data System (ADS)

Datta, S.; Ryan, B.; Kumar, N.; Bortz, T.; Bolen, Z. T.

2016-12-01

Threats of Arsenic (As) through food uptake, via consumption of rice, is a potential pathway that presents a concern not only for the millions of inhabitants who reside in river valleys and irrigate their soil with contaminated water, but the global rice market as well. This study focuses on high As rice from India and Bangladesh grown in such soils, and the effect of boiling rice with As-contaminated water in preparation for dietary intake. Husked and unhusked rice grains were boiled with >500 µg/L As-bearing water from the field to simulate local cooking methods. The resulting cooked water was analyzed using iCAP low limit detection via ICP-MS to understand the changes in dissolved elemental concentrations before and after cooking, and HPLC was introduced to measure for changes in As speciation in the waters. Using spectroscopic methods such as µXRF mapping associated with µXANES, distribution/localization and speciation changes of As in rice grains were identified. Further, with Linear Combination Fitting (LCF) of XANES spectra utilizing relevant reference compounds (As-S, AsIII, AsV, MMA and DMA), organic and inorganic As species were able to be mapped within rice grains. The results for uncooked/raw grains showed that predominantly As-S combined with AsIII and AsV accounted for 90% of speciation in most samples, localized in areas such as the outer aleurone layer. When analyzing cooked rice grains, the speciation appears to be an unidentified As species while the best LCF shows between 63-93% of As as MMA. Arsenic was found less localized throughout the cooked grains but rather heterogeneously distributed when compared to the uncooked/raw samples. The analyses of boiled/cooked water resulted in a significant decrease in dissolved As post-cooking (90%), but a subsequent increase in elements such as K, La, Li, Mo, Na, Ni, and Zr was observed; As-V was shown to be the main in-As species in the cooked water. The impact that this study portrays is consuming rice cooked by As-contaminated waters may not decrease the levels of As being consumed, but entitles further study on the specific health impacts that such cooked rice consumption could add to local population.

Next Generation Workload Management System For Big Data on Heterogeneous Distributed Computing

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

Klimentov, A.; Buncic, P.; De, K.

The Large Hadron Collider (LHC), operating at the international CERN Laboratory in Geneva, Switzerland, is leading Big Data driven scientific explorations. Experiments at the LHC explore the fundamental nature of matter and the basic forces that shape our universe, and were recently credited for the discovery of a Higgs boson. ATLAS and ALICE are the largest collaborations ever assembled in the sciences and are at the forefront of research at the LHC. To address an unprecedented multi-petabyte data processing challenge, both experiments rely on a heterogeneous distributed computational infrastructure. The ATLAS experiment uses PanDA (Production and Data Analysis) Workload Managementmore » System (WMS) for managing the workflow for all data processing on hundreds of data centers. Through PanDA, ATLAS physicists see a single computing facility that enables rapid scientific breakthroughs for the experiment, even though the data centers are physically scattered all over the world. The scale is demonstrated by the following numbers: PanDA manages O(10 2) sites, O(10 5) cores, O(10 8) jobs per year, O(10 3) users, and ATLAS data volume is O(10 17) bytes. In 2013 we started an ambitious program to expand PanDA to all available computing resources, including opportunistic use of commercial and academic clouds and Leadership Computing Facilities (LCF). The project titled 'Next Generation Workload Management and Analysis System for Big Data' (BigPanDA) is funded by DOE ASCR and HEP. Extending PanDA to clouds and LCF presents new challenges in managing heterogeneity and supporting workflow. The BigPanDA project is underway to setup and tailor PanDA at the Oak Ridge Leadership Computing Facility (OLCF) and at the National Research Center "Kurchatov Institute" together with ALICE distributed computing and ORNL computing professionals. Our approach to integration of HPC platforms at the OLCF and elsewhere is to reuse, as much as possible, existing components of the PanDA system. Finally, we will present our current accomplishments with running the PanDA WMS at OLCF and other supercomputers and demonstrate our ability to use PanDA as a portal independent of the computing facilities infrastructure for High Energy and Nuclear Physics as well as other data-intensive science applications.« less

OPENING REMARKS: Scientific Discovery through Advanced Computing

NASA Astrophysics Data System (ADS)

Strayer, Michael

2006-01-01

Good morning. Welcome to SciDAC 2006 and Denver. I share greetings from the new Undersecretary for Energy, Ray Orbach. Five years ago SciDAC was launched as an experiment in computational science. The goal was to form partnerships among science applications, computer scientists, and applied mathematicians to take advantage of the potential of emerging terascale computers. This experiment has been a resounding success. SciDAC has emerged as a powerful concept for addressing some of the biggest challenges facing our world. As significant as these successes were, I believe there is also significance in the teams that achieved them. In addition to their scientific aims these teams have advanced the overall field of computational science and set the stage for even larger accomplishments as we look ahead to SciDAC-2. I am sure that many of you are expecting to hear about the results of our current solicitation for SciDAC-2. I’m afraid we are not quite ready to make that announcement. Decisions are still being made and we will announce the results later this summer. Nearly 250 unique proposals were received and evaluated, involving literally thousands of researchers, postdocs, and students. These collectively requested more than five times our expected budget. This response is a testament to the success of SciDAC in the community. In SciDAC-2 our budget has been increased to about 70 million for FY 2007 and our partnerships have expanded to include the Environment and National Security missions of the Department. The National Science Foundation has also joined as a partner. These new partnerships are expected to expand the application space of SciDAC, and broaden the impact and visibility of the program. We have, with our recent solicitation, expanded to turbulence, computational biology, and groundwater reactive modeling and simulation. We are currently talking with the Department’s applied energy programs about risk assessment, optimization of complex systems - such as the national and regional electricity grid, carbon sequestration, virtual engineering, and the nuclear fuel cycle. The successes of the first five years of SciDAC have demonstrated the power of using advanced computing to enable scientific discovery. One measure of this success could be found in the President’s State of the Union address in which President Bush identified ‘supercomputing’ as a major focus area of the American Competitiveness Initiative. Funds were provided in the FY 2007 President’s Budget request to increase the size of the NERSC-5 procurement to between 100-150 teraflops, to upgrade the LCF Cray XT3 at Oak Ridge to 250 teraflops and acquire a 100 teraflop IBM BlueGene/P to establish the Leadership computing facility at Argonne. We believe that we are on a path to establish a petascale computing resource for open science by 2009. We must develop software tools, packages, and libraries as well as the scientific application software that will scale to hundreds of thousands of processors. Computer scientists from universities and the DOE’s national laboratories will be asked to collaborate on the development of the critical system software components such as compilers, light-weight operating systems and file systems. Standing up these large machines will not be business as usual for ASCR. We intend to develop a series of interconnected projects that identify cost, schedule, risks, and scope for the upgrades at the LCF at Oak Ridge, the establishment of the LCF at Argonne, and the development of the software to support these high-end computers. The critical first step in defining the scope of the project is to identify a set of early application codes for each leadership class computing facility. These codes will have access to the resources during the commissioning phase of the facility projects and will be part of the acceptance tests for the machines. Applications will be selected, in part, by breakthrough science, scalability, and ability to exercise key hardware and software components. Possible early applications might include climate models; studies of the magnetic properties of nanoparticles as they relate to ultra-high density storage media; the rational design of chemical catalysts, the modeling of combustion processes that will lead to cleaner burning coal, and fusion and astrophysics research. I have presented just a few of the challenges that we look forward to on the road to petascale computing. Our road to petascale science might be paraphrased by the quote from e e cummings, ‘somewhere I have never traveled, gladly beyond any experience . . .’

NASALife-Component Fatigue and Creep Life Prediction Program and Illustrative Examples

NASA Technical Reports Server (NTRS)

Murthy, Pappu L. N.; Mital, Subodh K.; Gyekenyesi, John Z.

2005-01-01

NASALife is a life prediction program for propulsion system components made of ceramic matrix composites (CMC) under cyclic thermo-mechanical loading and creep rupture conditions. Although, the primary focus was for CMC components the underlying methodologies are equally applicable to other material systems as well. The program references data for low cycle fatigue (LCF), creep rupture, and static material properties as part of the life prediction process. Multiaxial stresses are accommodated by Von Mises based methods and a Walker model is used to address mean stress effects. Varying loads are reduced by the Rainflow counting method. Lastly, damage due to cyclic loading (Miner s rule) and creep are combined to determine the total damage per mission and the number of missions the component can survive before failure are calculated. Illustration of code usage is provided through example problem of a CMC turbine stator vane made of melt-infiltrated, silicon carbide fiber-reinforced, silicon carbide matrix composite (MI SiC/SiC)

Chemical species of sulfur in prostate cancer cells studied by XANES spectroscopy

NASA Astrophysics Data System (ADS)

Czapla, Joanna; Kwiatek, Wojciech M.; Lekki, Janusz; Dulińska-Litewka, Joanna; Steininger, Ralph; Göttlicher, Jörg

2013-12-01

The role of sulfur in prostate cancer progression may be significant for understanding the process of carcinogenesis. This work, based on X-ray Absorption Near Edge Structure (XANES) spectroscopy, is focused on determination of sulfur chemical species occurring in prostate cancer cell lines. The experimental material consisted of four commercially available cell lines: three from metastasized prostate cancer (PC3, LNCaP, and DU145) and one, used as a control, from the non-tumourigenic peripheral zone of the prostate (PZ-HPV-7). The experiment was performed at the SUL-X beamline of the synchrotron radiation source ANKA, Karlsruhe (Germany). The K-edge XANES spectra of sulfur were analyzed by deconvolution in order to establish sulfur species that occur in prostate cancer cells and to find out whether there are any differences in their content between various cell lines. Experimental spectra were fitted in two ways: with two Gaussian peaks and one arctangent step function, and additionally by a Linear Combination Fit with spectra of reference compounds in order to obtain quantitative chemical information. All fitting procedures were performed with the Athena code (Ravel and Newville, 2005) and the results of deconvolution were used to determine the fraction of each sulfur form. The results of data analysis showed that cell lines from different metastasis had different ratio of reduced to oxidized sulfur species. The LCF analysis demonstrated that the highest content of GSH, one of the most important sulfur-bearing compounds in cells, was observed in DU145 cells. These findings may confirm the hypothesis of changes in redox balance in case of cancer initiation and progression.

Mechanisms of High-Temperature Fatigue Failure in Alloy 800H

NASA Technical Reports Server (NTRS)

BhanuSankaraRao, K.; Schuster, H.; Halford, G. R.

1996-01-01

The damage mechanisms influencing the axial strain-controlled Low-Cycle Fatigue (LCF) behavior of alloy 800H at 850 C have been evaluated under conditions of equal tension/compression ramp rates (Fast-Fast (F-F): 4 X 10(sup -3)/s and Slow-Slow (S-S): 4 X 10(sup -5)/s) and asymmetrical ramp rates (Fast-Slow (F-S): 4 x 10(sup -3)/s / 4 X 10(sup -5/s and Slow-Fast (S-F): 4 X 10(sup -5) / 4 X 10(sup -3)/s) in tension and compression. The fatigue life, cyclic stress response, and fracture modes were significantly influenced by the waveform shape. The fatigue lives displayed by different loading conditions were in the following order: F-F greater than S-S greater than F-S greater than S-F. The fracture mode was dictated by the ramp rate adopted in the tensile direction. The fast ramp rate in the tensile direction led to the occurrence of transgranular crack initiation and propagation, whereas the slow ramp rate caused intergranular initiation and propagation. The time-dependent processes and their synergistic interactions, which were at the basis of observed changes in cyclic stress response and fatigue life, were identified. Oxidation, creep damage, dynamic strain aging, massive carbide precipitation, time-dependent creep deformation, and deformation ratcheting were among the several factors influencing cyclic life. Irrespective of the loading condition, the largest effect on life was exerted by oxidation processes. Deformation ratcheting had its greatest influence on life under asymmetrical loading conditions. Creep damage accumulated the greatest amount during the slow tensile ramp under S-F conditions.

Materials for Advanced Ultrasupercritical Steam Turbines Task 4: Cast Superalloy Development

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

Thangirala, Mani

The Steam Turbine critical stationary structural components are high integrity Large Shell and Valve Casing heavy section Castings, containing high temperature steam under high pressures. Hence to support the development of advanced materials technology for use in an AUSC steam turbine capable of operating with steam conditions of 760°C (1400°F) and 35 Mpa (5000 psia), Casting alloy selection and evaluation of mechanical, metallurgical properties and castability with robust manufacturing methods are mandated. Alloy down select from Phase 1 based on producability criteria and creep rupture properties tested by NETL-Albany and ORNL directed the consortium to investigate cast properties of Haynesmore » 282 and Haynes 263. The goals of Task 4 in Phase 2 are to understand a broader range of mechanical properties, the impact of manufacturing variables on those properties. Scale up the size of heats to production levels to facilitate the understanding of the impact of heat and component weight, on metallurgical and mechanical behavior. GE Power & Water Materials and Processes Engineering for the Phase 2, Task 4.0 Castings work, systematically designed and executed casting material property evaluation, multiple test programs. Starting from 15 lbs. cylinder castings to world’s first 17,000 lbs. poured weight, heavy section large steam turbine partial valve Haynes 282 super alloy casting. This has demonstrated scalability of the material for steam Turbine applications. Activities under Task 4.0, Investigated and characterized various mechanical properties of Cast Haynes 282 and Cast Nimonic 263. The development stages involved were: 1) Small Cast Evaluation: 4 inch diam. Haynes 282 and Nimonic 263 Cylinders. This provided effects of liquidus super heat range and first baseline mechanical data on cast versions of conventional vacuum re-melted and forged Ni based super alloys. 2) Step block castings of 300 lbs. and 600 lbs. Haynes 282 from 2 foundry heats were evaluated which demonstrated the importance of proper heat treat cycles for Homogenization, and Solutionizing parameters selection and implementation. 3) Step blocks casting of Nimonic 263: Carried out casting solidification simulation analysis, NDT inspection methods evaluation, detailed test matrix for Chemical, Tensile, LCF, stress rupture, CVN impact, hardness and J1C Fracture toughness section sensitivity data and were reported. 4) Centrifugal Casting of Haynes 282, weighing 1400 lbs. with hybrid mold (half Graphite and half Chromite sand) mold assembly was cast using compressor casing production tooling. This test provided Mold cooling rates influence on centrifugally cast microstructure and mechanical properties. Graphite mold section out performs sand mold across all temperatures for 0.2% YS; %Elongation, %RA, UTS at 1400°F. Both Stress-LMP and conditional Fracture toughness plots data were in the scatter band of the wrought alloy. 5) Fundamental Studies on Cooling rates and SDAS test program. Evaluated the influence of 6 mold materials Silica, Chromite, Alumina, Silica with Indirect Chills, Zircon and Graphite on casting solidification cooling rates. Actual Casting cooling rates through Liquidus to Solidus phase transition were measured with 3 different locations based thermocouples placed in each mold. Compared with solidification simulation cooling rates and measurement of SDAS, microstructure features were reported. The test results provided engineered casting potential methods, applicable for heavy section Haynes 282 castings for optimal properties, with foundry process methods and tools. 6) Large casting of Haynes 282 Drawings and Engineering FEM models and supplemental requirements with applicable specifications were provided to suppliers for the steam turbine proto type feature valve casing casting. Molding, melting and casting pouring completed per approved Manufacturing Process Plan during 2014 Q4. The partial valve casing was successfully cast after casting methods were validated with solidification simulation analysis and the casting met NDT inspection and acceptance criteria. Heat treated and sectioned to extract trepan samples at different locations comparing with cast on coupons test data. Material properties requisite for design, such as tensile, creep/rupture, LCF, Fracture Toughness, Charpy V-notch chemical analysis testing were carried out. The test results will be presented in the final report. The typical Haynes 282 large size Steam Turbine production casting from Order to Delivery foundry schedule with the activity break up is shown in Figures 107 and 108. • From Purchase Order placement to Casting pouring ~ 26 weeks. 1. Sales and commercial review 3 2. Engineering Drawings/models review 4 3. Pattern and core box manufacturing 6 4. Casting process engineering review 4 5. FEM and solidification simulation analysis 4 6. Gating & Feeder Attachments, Ceramic tiling 2 7. Molding and coremaking production scheduling 6 8. Melting planning and schedule 3 9. Pouring, cooling and shake out 2 • From Pouring to casting Delivery ~ 29 weeks 10. Shot blast and riser cutting, gates removal 3 11. Homogenizing , solutionizing HT furnace prep 4 12. Grinding, Fettling 2 13. Aging HT Cycle, cooling 2 14. VT and LPT NDT inspections 2 15. Radiographic inspection 4 16. Mechanical testing, Chemical analysis test certs 4 17. Casting weld repair upgrades and Aging PWHT 4 18. NDT after weld repairs and casting upgrades 3 19. Casting Final Inspection and test certifications 3 20. Package and delivery 2 Hence the Total Lead time from P.O to Casting delivery is approximately 55 weeks. The Task 4.2 and Task 4.3 activities and reporting completed.« less

Impact of Fe(III)-OM complexes and Fe(III) polymerization on SOM pools reactivity under different land uses

NASA Astrophysics Data System (ADS)

Giannetta, B.; Plaza, C.; Zaccone, C.; Siebecker, M. G.; Rovira, P.; Vischetti, C.; Sparks, D. L.

2017-12-01

Soil organic matter (SOM) protection and long-term accumulation are controlled by adsorption to mineral surfaces in different ways, depending on its molecular structure and pedo-climatic conditions. Iron (Fe) oxides are known to be key regulators of the soil carbon (C) cycle, and Fe speciation in soils is highly dependent on environmental conditions and chemical interactions with SOM. However, the molecular structure and hydrolysis of Fe species formed in association with SOM is still poorly described. We hypothesize the existence of two pools of Fe which interact with SOM: mononuclear Fe(III)-SOM complexes and precipitated Fe(III) hydroxides. To verify our hypothesis, we investigated the interactions between Fe(III) and physically isolated soil fractions by means of batch experiments at pH 7. Specifically, we examined the fine silt plus clay (FSi+C) fraction, obtained by ultrasonic dispersion and wet sieving. The soil samples spanned several land uses, including coniferous forest (CFS), grassland (GS), technosols (TS) and agricultural (AS) soils. Solid phase products and supernatants were analyzed for C and Fe content. X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) analysis were also performed. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was used to assess the main C functional groups involved in C complexation and desorption experiments. Preliminary linear combination fitting (LCF) of Fe K-edge extended X-ray absorption fine structure (EXAFS) spectra suggested the formation of ferrihydrite-like polymeric Fe(III) oxides in reacted CFS and GS samples, with higher C and Fe concentration. Conversely, mononuclear Fe(III) OM complexes dominated the speciation for TS and AS samples, characterized by lower C and Fe concentration, inhibiting the hydrolysis and polymerization of Fe (III). This approach will help revealing the mechanisms by which SOM pools can control Fe(III) speciation, and will elucidate how both Fe(III)-OM complexes and Fe(III) polymerization can affect SOM reactivity and, consequently, its mean residence time in different ecosystems.

GRCop-84: A High Temperature Copper-based Alloy For High Heat Flux Applications

NASA Technical Reports Server (NTRS)

Ellis, David L.

2005-01-01

While designed for rocket engine main combustion chamber liners, GRCop-84 (Cu-8 at.% Cr-4 at.% Nb) offers potential for high heat flux applications in industrial applications requiring a temperature capability up to approximately 700 C (1292 F). GRCop-84 is a copper-based alloy with excellent elevated temperature strength, good creep resistance, long LCF lives and enhanced oxidation resistance. It also has a lower thermal expansion than copper and many other low alloy copper-based alloys. GRCop-84 can be manufactured into a variety of shapes such as tubing, bar, plate and sheet using standard production techniques and requires no special production techniques. GRCop-84 forms well, so conventional fabrication methods including stamping and bending can be used. GRCop-84 has demonstrated an ability to be friction stir welded, brazed, inertia welded, diffusion bonded and electron beam welded for joining to itself and other materials. Potential applications include plastic injection molds, resistance welding electrodes and holders, permanent metal casting molds, vacuum plasma spray nozzles and high temperature heat exchanger applications.

Multistage reaction pathways in detonating high explosives

NASA Astrophysics Data System (ADS)

Li, Ying; Kalia, Rajiv; Nakano, Aiichiro; Vashishta, Priya; CACS Collaboration; ALCF Team

2015-06-01

Atomistic mechanisms underlying the reaction time and intermediate reaction products of detonating high explosives far from equilibrium have been elusive. This is because detonation is one of the hardest multiscale physics problems, in which diverse length and time scales play important roles. Here, large spatiotemporal-scale reactive molecular dynamics simulations validated by quantum molecular dynamics simulations reveal a two-stage reaction mechanism during the detonation of cyclotrimethylenetrinitramine crystal. Rapid production of N2 and H2O within 10 ps is followed by delayed production of CO molecules beyond ns. We found that further decomposition towards the final products is inhibited by the formation of large metastable carbon- and oxygen-rich clusters with fractal geometry. In addition, we found distinct uni-molecular and intermolecular reaction pathways, respectively, for the rapid N2 and H2O productions. This work was supported by the Office of Naval Research Grant No. N000014-12-1-0555 and the Basic Research Program of Defense Threat Reduction Agency (DTRA) Grant No. HDTRA1-08-1-0036. All the simulations were performed at USC and Argonne LCF.

Effect of Crystal Orientation on Fatigue Failure of Single Crystal Nickel Base Turbine Blade Superalloys

NASA Technical Reports Server (NTRS)

Arakere, N. K.; Swanson, G.

2002-01-01

High cycle fatigue (HCF) induced failures in aircraft gas turbine and rocket engine turbopump blades is a pervasive problem. Single crystal nickel turbine blades are being utilized in rocket engine turbopumps and jet engines throughout industry because of their superior creep, stress rupture, melt resistance, and thermomechanical fatigue capabilities over polycrystalline alloys. Currently the most widely used single crystal turbine blade superalloys are PWA 1480/1493, PWA 1484, RENE' N-5 and CMSX-4. These alloys play an important role in commercial, military and space propulsion systems. Single crystal materials have highly orthotropic properties making the position of the crystal lattice relative to the part geometry a significant factor in the overall analysis. The failure modes of single crystal turbine blades are complicated to predict due to the material orthotropy and variations in crystal orientations. Fatigue life estimation of single crystal turbine blades represents an important aspect of durability assessment. It is therefore of practical interest to develop effective fatigue failure criteria for single crystal nickel alloys and to investigate the effects of variation of primary and secondary crystal orientation on fatigue life. A fatigue failure criterion based on the maximum shear stress amplitude /Delta(sub tau)(sub max))] on the 24 octahedral and 6 cube slip systems, is presented for single crystal nickel superalloys (FCC crystal). This criterion reduces the scatter in uniaxial LCF test data considerably for PWA 1493 at 1200 F in air. Additionally, single crystal turbine blades used in the alternate advanced high-pressure fuel turbopump (AHPFTP/AT) are modeled using a large-scale three-dimensional finite element model. This finite element model is capable of accounting for material orthotrophy and variation in primary and secondary crystal orientation. Effects of variation in crystal orientation on blade stress response are studied based on 297 finite element model runs. Fatigue lives at critical points in the blade are computed using finite element stress results and the failure criterion developed. Stress analysis results in the blade attachment region are also presented. Results presented demonstrates that control of secondary and primary crystallographic orientation has the potential to significantly increase a component S resistance to fatigue crack growth with- out adding additional weight or cost. [DOI: 10.1115/1.1413767

Enrichment of spinal cord cell cultures with motoneurons

PubMed Central

1978-01-01

Spinal cord cell cultures contain several types of neurons. Two methods are described for enriching such cultures with motoneurons (defined here simply as cholinergic cells that are capable of innervating muscle). In the first method, 7-day embryonic chick spinal cord neurons were separated according to size by 1 g velocity sedimentation. It is assumed that cholinergic motoneurons are among the largest cells present at this stage. The spinal cords were dissociated vigorously so that 95-98% of the cells in the initial suspension were isolated from one another. Cells in leading fractions (large cell fractions: LCFs) contain about seven times as much choline acetyltransferase (CAT) activity per unit cytoplasm as do cells in trailing fractions (small cell fractions: SCFs). Muscle cultures seeded with LCFs develop 10-70 times as much CAT as cultures seeded with SCFs and six times as much CAT as cultures seeded with control (unfractionated) spinal cord cells. More than 20% of the large neurons in LCF-muscle cultures innervate nearby myotubes. In the second method, neurons were gently dissociated from 4-day embryonic spinal cords and maintained in vitro. This approach is based on earlier observations that cholinergic neurons are among the first cells to withdraw form the mitotic cycle in the developing chick embryo (Hamburger, V. 1948. J. Comp. Neurol. 88:221- 283; and Levi-Montalcini, R. 1950. J. Morphol. 86:253-283). 4-Day spinal cord-muscle cultures develop three times as much CAT as do 7-day spinal cord-muscle plates, prepared in the same (gentle) manner. More than 50% of the relatively large 4-day neurons innervate nearby myotubes. Thus, both methods are useful first steps toward the complete isolation of motoneurons. Both methods should facilitate study of the development of cholinergic neurons and of nerve-muscle synapse formation. PMID:566275

High Sensitive Methods for Health Monitoring of Compressor Blades and Fatigue Detection

PubMed Central

Witoś, Mirosław

2013-01-01

The diagnostic and research aspects of compressor blade fatigue detection have been elaborated in the paper. The real maintenance and overhaul problems and characteristic of different modes of metal blade fatigue (LCF, HCF, and VHCF) have been presented. The polycrystalline defects and impurities influencing the fatigue, along with their related surface finish techniques, are taken into account. The three experimental methods of structural health assessment are considered. The metal magnetic memory (MMM), experimental modal analysis (EMA) and tip timing (TTM) methods provide information on the damage of diagnosed objects, for example, compressor blades. Early damage symptoms, that is, magnetic and modal properties of material strengthening and weakening phases (change of local dislocation density and grain diameter, increase of structural and magnetic anisotropy), have been described. It has been proven that the shape of resonance characteristic gives abilities to determine if fatigue or a blade crack is concerned. The capabilities of the methods for steel and titanium alloy blades have been illustrated in examples from active and passive experiments. In the conclusion, the MMM, EMA, and TTM have been verified, and the potential for reliable diagnosis of the compressor blades using this method has been confirmed. PMID:24191135

The Arctic clouds from model simulations and long-term observations at Barrow, Alaska

NASA Astrophysics Data System (ADS)

Zhao, Ming

The Arctic is a region that is very sensitive to global climate change while also experiencing significant changes in its surface air temperature, sea-ice cover, atmospheric circulation, precipitation, snowfall, biogeochemical cycling, and land surface. Although previous studies have shown that the arctic clouds play an important role in the arctic climate changes, the arctic clouds are poorly understood and simulated in climate model due to limited observations. Furthermore, most of the studies were based on short-term experiments and typically only cover the warm seasons, which do not provide a full understanding of the seasonal cycle of arctic clouds. To address the above concerns and to improve our understanding of arctic clouds, six years of observational and retrieval data from 1999 to 2004 at the Atmospheric Radiation Management (ARM) Climate Research Facility (ACRF) North Slope of Alaska (NSA) Barrow site are used to understand the arctic clouds and related radiative processes. In particular, we focus on the liquid-ice mass partition in the mixed-phase cloud layer. Statistical results show that aerosol type and concentration are important factors that impact the mixed-phase stratus (MPS) cloud microphysical properties: liquid water path (LWP) and liquid water fraction (LWF) decrease with the increase of cloud condensation nuclei (CCN) number concentration; the high dust loading and dust occurrence in the spring are possible reasons for the much lower LWF than the other seasons. The importance of liquid-ice mass partition on surface radiation budgets was analyzed by comparing cloud longwave radiative forcings under the same LWP but different ice water path (IWP) ranges. Results show the ice phase enhance the surface cloud longwave (LW) forcing by 8˜9 W m-2 in the moderately thin MPS. This result provides an observational evidence on the aerosol glaciation effect in the moderately thin MPS, which is largely unknown so far. The above new insights are important to guide the model parameterizations of liquid-ice mass partition in arctic mixed-phase clouds, and are served as a test bed to cloud models and cloud microphysical schemes. The observational data between 1999 and 2007 are used to assess the performance of the European Center for Medium-Range Weather Forecasts (ECMWF) model in the Arctic region. The ECMWF model-simulated near-surface humidity had seasonal dependent biases as large as 20%, while also experiencing difficulty representing boundary layer (BL) temperature inversion height and strength during the transition seasons. Although the ECMWF model captured the seasonal variation of surface heat fluxes, it had sensible heat flux biases over 20 W m-2 in most of the cold months. Furthermore, even though the model captured the general seasonal variations of low-level cloud fraction (LCF) and LWP, it still overestimated the LCF by 20% or more and underestimated the LWP over 50% in the cold season. On average, the ECMWF model underestimated LWP by ˜30 g m-2 but more accurately predicted ice water path for BL clouds. For BL mixed-phase clouds, the model predicted water-ice mass partition was significantly lower than the observations, largely due to the temperature dependence of water-ice mass partition used in the model. The new cloud and BL schemes of the ECMWF model that were implemented after 2003 only resulted in minor improvements in BL cloud simulations in summer. These results indicate that significant improvements in cold season BL and mixed-phase cloud processes in the model are needed. In this study, single-layer MPS clouds were simulated by the Weather Research and Forecasting (WRF) model under different microphysical schemes and different ice nuclei (IN) number concentrations. Results show that by using proper IN concentration, the WRF model incorporated with Morrison microphysical scheme can reasonably capture the observed seasonal differences in temperature dependent liquid-ice mass partition. However, WRF simulations underestimate both LWP and IWP indicating its deficiency in capturing the radiative impacts of arctic MPS clouds.

Surfactin, Iturin, and Fengycin Biosynthesis by Endophytic Bacillus sp. from Bacopa monnieri.

PubMed

Jasim, B; Sreelakshmi, K S; Mathew, Jyothis; Radhakrishnan, E K

2016-07-01

Endophytic microorganisms which are ubiquitously present in plants may colonize intracellularly or intercellularly without causing any diseases. By living within the unique chemical environment of a host plant, they produce a vast array of compounds with a wide range of biological activities. Because of this, natural products of endophytic origin have been exploited for antimicrobial, antiviral, anticancer, and antioxidant properties. Also, they can be considered to function as an efficient microbial barrier to protect plants from various pathogens. In the present study, endophytic bacterium BmB 9 with antifungal and antibacterial activity isolated from the stem tissue of Bacopa monnieri was studied for the molecular and chemical basis of its activity. PCR-based genome mining for various biosynthetic gene clusters proved the presence of surfactin, iturin, and type I polyketide synthase (PKS) genes in the isolate. The LC-MS/MS based analysis of the extract further confirmed the production of surfactin derivatives (M + H(+)-1008.6602, 1022.6755), iturin (M + H(+)-1043.5697), and fengycin (M + H(+)-1491.8195, 1477.8055) by the selected bacterial isolate. The 16S rDNA sequence similarity based analysis identified the isolate BmB 9 as Bacillus sp. with 100 % identity to Bacillus sp. LCF1 (KP257289).

Weibull-Based Design Methodology for Rotating Aircraft Engine Structures

NASA Technical Reports Server (NTRS)

Zaretsky, Erwin; Hendricks, Robert C.; Soditus, Sherry

2002-01-01

The NASA Energy Efficient Engine (E(sup 3)-Engine) is used as the basis of a Weibull-based life and reliability analysis. Each component's life and thus the engine's life is defined by high-cycle fatigue (HCF) or low-cycle fatigue (LCF). Knowing the cumulative life distribution of each of the components making up the engine as represented by a Weibull slope is a prerequisite to predicting the life and reliability of the entire engine. As the engine Weibull slope increases, the predicted lives decrease. The predicted engine lives L(sub 5) (95 % probability of survival) of approximately 17,000 and 32,000 hr do correlate with current engine maintenance practices without and with refurbishment. respectively. The individual high pressure turbine (HPT) blade lives necessary to obtain a blade system life L(sub 0.1) (99.9 % probability of survival) of 9000 hr for Weibull slopes of 3, 6 and 9, are 47,391 and 20,652 and 15,658 hr, respectively. For a design life of the HPT disks having probable points of failure equal to or greater than 36,000 hr at a probability of survival of 99.9 %, the predicted disk system life L(sub 0.1) can vary from 9,408 to 24,911 hr.

Comparisons between tokamak fueling of gas puffing and supersonic molecular beam injection in 2D simulations

DOE PAGES

Zhou, Y. L.; Wang, Z. H.; Xu, X. Q.; ...

2015-01-09

Plasma fueling with high efficiency and deep injection is very important to enable fusion power performance requirements. It is a powerful and efficient way to study neutral transport dynamics and find methods of improving the fueling performance by doing large scale simulations. Furthermore, two basic fueling methods, gas puffing (GP) and supersonic molecular beam injection (SMBI), are simulated and compared in realistic divertor geometry of the HL-2A tokamak with a newly developed module, named trans-neut, within the framework of BOUT++ boundary plasma turbulence code [Z. H. Wang et al., Nucl. Fusion 54, 043019 (2014)]. The physical model includes plasma density,more » heat and momentum transport equations along with neutral density, and momentum transport equations. In transport dynamics and profile evolutions of both plasma and neutrals are simulated and compared between GP and SMBI in both poloidal and radial directions, which are quite different from one and the other. It finds that the neutrals can penetrate about four centimeters inside the last closed (magnetic) flux surface during SMBI, while they are all deposited outside of the LCF during GP. Moreover, it is the radial convection and larger inflowing flux which lead to the deeper penetration depth of SMBI and higher fueling efficiency compared to GP.« less

Comparisons between tokamak fueling of gas puffing and supersonic molecular beam injection in 2D simulations

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

Zhou, Y. L.; Wang, Z. H.; Xu, X. Q.

Plasma fueling with high efficiency and deep injection is very important to enable fusion power performance requirements. It is a powerful and efficient way to study neutral transport dynamics and find methods of improving the fueling performance by doing large scale simulations. Furthermore, two basic fueling methods, gas puffing (GP) and supersonic molecular beam injection (SMBI), are simulated and compared in realistic divertor geometry of the HL-2A tokamak with a newly developed module, named trans-neut, within the framework of BOUT++ boundary plasma turbulence code [Z. H. Wang et al., Nucl. Fusion 54, 043019 (2014)]. The physical model includes plasma density,more » heat and momentum transport equations along with neutral density, and momentum transport equations. In transport dynamics and profile evolutions of both plasma and neutrals are simulated and compared between GP and SMBI in both poloidal and radial directions, which are quite different from one and the other. It finds that the neutrals can penetrate about four centimeters inside the last closed (magnetic) flux surface during SMBI, while they are all deposited outside of the LCF during GP. Moreover, it is the radial convection and larger inflowing flux which lead to the deeper penetration depth of SMBI and higher fueling efficiency compared to GP.« less

Comparisons between tokamak fueling of gas puffing and supersonic molecular beam injection in 2D simulations

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

Zhou, Y. L.; Southwestern Institute of Physics, Chengdu 610041; Wang, Z. H., E-mail: zhwang@swip.ac.cn

Plasma fueling with high efficiency and deep injection is very important to enable fusion power performance requirements. It is a powerful and efficient way to study neutral transport dynamics and find methods of improving the fueling performance by doing large scale simulations. Two basic fueling methods, gas puffing (GP) and supersonic molecular beam injection (SMBI), are simulated and compared in realistic divertor geometry of the HL-2A tokamak with a newly developed module, named trans-neut, within the framework of BOUT++ boundary plasma turbulence code [Z. H. Wang et al., Nucl. Fusion 54, 043019 (2014)]. The physical model includes plasma density, heatmore » and momentum transport equations along with neutral density, and momentum transport equations. Transport dynamics and profile evolutions of both plasma and neutrals are simulated and compared between GP and SMBI in both poloidal and radial directions, which are quite different from one and the other. It finds that the neutrals can penetrate about four centimeters inside the last closed (magnetic) flux surface during SMBI, while they are all deposited outside of the LCF during GP. It is the radial convection and larger inflowing flux which lead to the deeper penetration depth of SMBI and higher fueling efficiency compared to GP.« less

Zinc speciation in the suspended particulate matter of an urban river (Orge, France): influence of seasonality and urbanization gradient.

PubMed

Le Pape, Pierre; Quantin, Cécile; Morin, Guillaume; Jouvin, Delphine; Kieffer, Isabelle; Proux, Olivier; Ghanbaja, Jaafar; Ayrault, Sophie

2014-10-21

Among trace metal pollutants, zinc is the major one in the rivers from the Paris urban area, such as the Orge River, where Zn concentration in the suspended particulate matter (SPM) can reach 2000 mg/kg in the most urbanized areas. In order to better understand Zn cycling in such urban rivers, we have determined Zn speciation in SPM as a function of both the seasonal water flow variations and the urbanization gradient along the Orge River. Using TEM/SEM-EDX and linear combination fitting (LCF) of EXAFS data at the Zn K-edge, we show that Zn mainly occurs as tetrahedrally coordinated Zn(2+) sorbed to ferrihydrite (37-46%), calcite (0-37%), amorphous SiO2 (0-21%), and organic-P (0-30%) and as octahedrally coordinated Zn(2+) in the octahedral layer of phyllosilicates (18-25%). Moreover, the Zn speciation pattern depends on the river flow rate. At low water flow, Zn speciation changes along the urbanization gradient: geogenic forms of Zn inherited from soil erosion decrease relative to Zn bound to organic-phosphates and amorphous SiO2. At high water flow, Zn speciation is dominated by soil-borne forms of Zn regardless the degree of urbanization, indicating that erosion of Zn-bearing minerals dominates the Zn contribution to SPM under such conditions.

Comparison of Microstructure and Mechanical Properties of Scalmalloy® Produced by Selective Laser Melting and Laser Metal Deposition.

PubMed

Awd, Mustafa; Tenkamp, Jochen; Hirtler, Markus; Siddique, Shafaqat; Bambach, Markus; Walther, Frank

2017-12-23

The second-generation aluminum-magnesium-scandium (Al-Mg-Sc) alloy, which is often referred to as Scalmalloy ® , has been developed as a high-strength aluminum alloy for selective laser melting (SLM). The high-cooling rates of melt pools during SLM establishes the thermodynamic conditions for a fine-grained crack-free aluminum structure saturated with fine precipitates of the ceramic phase Al₃-Sc. The precipitation allows tensile and fatigue strength of Scalmalloy ® to exceed those of AlSi10Mg by ~70%. Knowledge about properties of other additive manufacturing processes with slower cooling rates is currently not available. In this study, two batches of Scalmalloy ® processed by SLM and laser metal deposition (LMD) are compared regarding microstructure-induced properties. Microstructural strengthening mechanisms behind enhanced strength and ductility are investigated by scanning electron microscopy (SEM). Fatigue damage mechanisms in low-cycle (LCF) to high-cycle fatigue (HCF) are a subject of study in a combined strategy of experimental and statistical modeling for calculation of Woehler curves in the respective regimes. Modeling efforts are supported by non-destructive defect characterization in an X-ray computed tomography (µ-CT) platform. The investigations show that Scalmalloy ® specimens produced by LMD are prone to extensive porosity, contrary to SLM specimens, which is translated to ~30% lower fatigue strength.

Comparison of Microstructure and Mechanical Properties of Scalmalloy® Produced by Selective Laser Melting and Laser Metal Deposition

PubMed Central

Awd, Mustafa; Tenkamp, Jochen; Hirtler, Markus; Siddique, Shafaqat; Bambach, Markus; Walther, Frank

2017-01-01

The second-generation aluminum-magnesium-scandium (Al-Mg-Sc) alloy, which is often referred to as Scalmalloy®, has been developed as a high-strength aluminum alloy for selective laser melting (SLM). The high-cooling rates of melt pools during SLM establishes the thermodynamic conditions for a fine-grained crack-free aluminum structure saturated with fine precipitates of the ceramic phase Al3-Sc. The precipitation allows tensile and fatigue strength of Scalmalloy® to exceed those of AlSi10Mg by ~70%. Knowledge about properties of other additive manufacturing processes with slower cooling rates is currently not available. In this study, two batches of Scalmalloy® processed by SLM and laser metal deposition (LMD) are compared regarding microstructure-induced properties. Microstructural strengthening mechanisms behind enhanced strength and ductility are investigated by scanning electron microscopy (SEM). Fatigue damage mechanisms in low-cycle (LCF) to high-cycle fatigue (HCF) are a subject of study in a combined strategy of experimental and statistical modeling for calculation of Woehler curves in the respective regimes. Modeling efforts are supported by non-destructive defect characterization in an X-ray computed tomography (µ-CT) platform. The investigations show that Scalmalloy® specimens produced by LMD are prone to extensive porosity, contrary to SLM specimens, which is translated to ~30% lower fatigue strength. PMID:29295528

Ex vivo inhibition of Clostridium botulinum neurotoxin types B, C, E, and F by small molecular weight inhibitors.

PubMed

Montgomery, Vicki A; Ahmed, S Ashraf; Olson, Mark A; Mizanur, Rahman M; Stafford, Robert G; Roxas-Duncan, Virginia I; Smith, Leonard A

2015-05-01

Two small molecular weight inhibitors, compounds CB7969312 and CB7967495, that displayed inhibition of botulinum neurotoxin serotype A in a previous study, were evaluated for inhibition of botulinum neurotoxin serotypes B, C, E, and F. The small molecular weight inhibitors were assessed by molecular modeling, UPLC-based peptide cleavage assay; and an ex vivo assay, the mouse phrenic nerve - hemidiaphragm assay (MPNHDA). While both compounds were inhibitors of botulinum neurotoxin (BoNT) serotypes B, C, and F in the MPNHDA, compound CB7969312 was effective at lower molar concentrations than compound CB7967495. However, compound CB7967495 was significantly more effective at preventing BoNTE intoxication than compound CB7969312. In the UPLC-based peptide cleavage assay, CB7969312 was also more effective against LcC. Both compounds inhibited BoNTE, but not BoNTF, LcE, or LcF in the UPLC-based peptide cleavage assay. Molecular modeling studies predicted that both compounds would be effective inhibitors of BoNTs B, C, E, and F. But CB7967495 was predicted to be a more effective inhibitor of the four serotypes (B, C, E, and F) than CB7969312. This is the first report of a small molecular weight compound that inhibits serotypes B, C, E, and F in the ex vivo assay. Published by Elsevier Ltd.

Understanding the Reliability of Solder Joints Used in Advanced Structural and Electronics Applications: Part 2 - Reliability Performance.

DOE PAGES

Vianco, Paul T.

2017-03-01

Whether structural or electronic, all solder joints must provide the necessary level of reliability for the application. The Part 1 report examined the effects of filler metal properties and the soldering process on joint reliability. Filler metal solderability and mechanical properties, as well as the extents of base material dissolution and interface reaction that occur during the soldering process, were shown to affect reliability performance. The continuation of this discussion is presented in this Part 2 report, which highlights those factors that directly affect solder joint reliability. There is the growth of an intermetallic compound (IMC) reaction layer at themore » solder/base material interface by means of solid-state diffusion processes. In terms of mechanical response by the solder joint, fatigue remains as the foremost concern for long-term performance. Thermal mechanical fatigue (TMF), a form of low-cycle fatigue (LCF), occurs when temperature cycling is combined with mismatched values of the coefficient of thermal expansion (CTE) between materials comprising the solder joint “system.” Vibration environments give rise to high-cycle fatigue (HCF) degradation. Although accelerated aging studies provide valuable empirical data, too many variants of filler metals, base materials, joint geometries, and service environments are forcing design engineers to embrace computational modeling to predict the long-term reliability of solder joints.« less

Risk assessment during transport of radioactive materials through the Suez Canal

NASA Astrophysics Data System (ADS)

Sabek, M. G.; El-Shinawy, R. M. K.; Gomaa, M.

1997-03-01

In this paper a study for risk assessment of the impact of transporting radioactive materials, during the period 1986-1992, through the Suez Canal of Egypt is given. The code RADTRAN-IV was used for this study. The results of the code, for a normal case, show that the transportation of low activity materials such as uranium (U 3O 8) represent the main items that contribute significantly to the collective dose within the Suez Canal area (Port-Said, Ismailia and Suez). The values of the annual collective dose due to transportation of all radionuclide materials was found to be at a maximum in Suez town and is equal to 5.04 × 10 -8 Man-Sv for the whole populations. If we only consider the workder at the harbour (estimated to be 50 persons), the value of the annual collective dose is about 3.33 × 10 -4 Man-Sv. These values are less than the exemption value of 1 Man-Sv recommended by the IAEA. For the accident case, the following pathways are considered by the code: ground-shine, direct inhalation, inhalation of resuspended material and cloud-shine. The total values of the estimated risks for each radionuclide material are presented in table form and, in addition, health effects (genetic effects, GE, and latent cancer fatality), LCF) are discussed. The calculated values of the radiological risks are very low for the three towns, showing that no radiation-induced early deaths are to be expected.

The C terminus of the catalytic domain of type A botulinum neurotoxin may facilitate product release from the active site.

PubMed

Mizanur, Rahman M; Frasca, Verna; Swaminathan, Subramanyam; Bavari, Sina; Webb, Robert; Smith, Leonard A; Ahmed, S Ashraf

2013-08-16

Botulinum neurotoxins are the most toxic of all compounds. The toxicity is related to a poor zinc endopeptidase activity located in a 50-kDa domain known as light chain (Lc) of the toxin. The C-terminal tail of Lc is not visible in any of the currently available x-ray structures, and it has no known function but undergoes autocatalytic truncations during purification and storage. By synthesizing C-terminal peptides of various lengths, in this study, we have shown that these peptides competitively inhibit the normal catalytic activity of Lc of serotype A (LcA) and have defined the length of the mature LcA to consist of the first 444 residues. Two catalytically inactive mutants also inhibited LcA activity. Our results suggested that the C terminus of LcA might interact at or near its own active site. By using synthetic C-terminal peptides from LcB, LcC1, LcD, LcE, and LcF and their respective substrate peptides, we have shown that the inhibition of activity is specific only for LcA. Although a potent inhibitor with a Ki of 4.5 μm, the largest of our LcA C-terminal peptides stimulated LcA activity when added at near-stoichiometric concentration to three versions of LcA differing in their C-terminal lengths. The result suggested a product removal role of the LcA C terminus. This suggestion is supported by a weak but specific interaction determined by isothermal titration calorimetry between an LcA C-terminal peptide and N-terminal product from a peptide substrate of LcA. Our results also underscore the importance of using a mature LcA as an inhibitor screening target.

Leptin Is Associated With Exaggerated Brain Reward and Emotion Responses to Food Images in Adolescent Obesity

PubMed Central

Jastreboff, Ania M.; Lacadie, Cheryl; Seo, Dongju; Kubat, Jessica; Van Name, Michelle A.; Giannini, Cosimo; Savoye, Mary; Constable, R. Todd; Sherwin, Robert S.

2014-01-01

OBJECTIVE In the U.S., an astonishing 12.5 million children and adolescents are now obese, predisposing 17% of our nation’s youth to metabolic complications of obesity, such as type 2 diabetes (T2D). Adolescent obesity has tripled over the last three decades in the setting of food advertising directed at children. Obese adults exhibit increased brain responses to food images in motivation-reward pathways. These neural alterations may be attributed to obesity-related metabolic changes, which promote food craving and high-calorie food (HCF) consumption. It is not known whether these metabolic changes affect neural responses in the adolescent brain during a crucial period for establishing healthy eating behaviors. RESEARCH DESIGN AND METHODS Twenty-five obese (BMI 34.4 kg/m2, age 15.7 years) and fifteen lean (BMI 20.96 kg/m2, age 15.5 years) adolescents underwent functional MRI during exposure to HCF, low-calorie food (LCF), and nonfood (NF) visual stimuli 2 h after isocaloric meal consumption. RESULTS Brain responses to HCF relative to NF cues increased in obese versus lean adolescents in striatal-limbic regions (i.e., putamen/caudate, insula, amygdala) (P < 0.05, family-wise error [FWE]), involved in motivation-reward and emotion processing. Higher endogenous leptin levels correlated with increased neural activation to HCF images in all subjects (P < 0.05, FWE). CONCLUSIONS This significant association between higher circulating leptin and hyperresponsiveness of brain motivation-reward regions to HCF images suggests that dysfunctional leptin signaling may contribute to the risk of overconsumption of these foods, thus further predisposing adolescents to the development of obesity and T2D. PMID:25139883

Leptin is associated with exaggerated brain reward and emotion responses to food images in adolescent obesity.

PubMed

Jastreboff, Ania M; Lacadie, Cheryl; Seo, Dongju; Kubat, Jessica; Van Name, Michelle A; Giannini, Cosimo; Savoye, Mary; Constable, R Todd; Sherwin, Robert S; Caprio, Sonia; Sinha, Rajita

2014-11-01

In the U.S., an astonishing 12.5 million children and adolescents are now obese, predisposing 17% of our nation's youth to metabolic complications of obesity, such as type 2 diabetes (T2D). Adolescent obesity has tripled over the last three decades in the setting of food advertising directed at children. Obese adults exhibit increased brain responses to food images in motivation-reward pathways. These neural alterations may be attributed to obesity-related metabolic changes, which promote food craving and high-calorie food (HCF) consumption. It is not known whether these metabolic changes affect neural responses in the adolescent brain during a crucial period for establishing healthy eating behaviors. Twenty-five obese (BMI 34.4 kg/m2, age 15.7 years) and fifteen lean (BMI 20.96 kg/m2, age 15.5 years) adolescents underwent functional MRI during exposure to HCF, low-calorie food (LCF), and nonfood (NF) visual stimuli 2 h after isocaloric meal consumption. Brain responses to HCF relative to NF cues increased in obese versus lean adolescents in striatal-limbic regions (i.e., putamen/caudate, insula, amygdala) (P < 0.05, family-wise error [FWE]), involved in motivation-reward and emotion processing. Higher endogenous leptin levels correlated with increased neural activation to HCF images in all subjects (P < 0.05, FWE). This significant association between higher circulating leptin and hyperresponsiveness of brain motivation-reward regions to HCF images suggests that dysfunctional leptin signaling may contribute to the risk of overconsumption of these foods, thus further predisposing adolescents to the development of obesity and T2D. © 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Influence of H 2O and H 2S on the composition, activity, and stability of sulfided Mo, CoMo, and NiMo supported on MgAl 2O 4 for hydrodeoxygenation of ethylene glycol

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

Dabros, Trine Marie Hartmann; Gaur, Abhijeet; Pintos, Delfina Garcia

Here in this work, density functional theory (DFT), catalytic activity tests, and in-situ X-ray absorption spectroscopy (XAS) was performed to gain detailed insights into the activity and stability of MoS 2, Ni-MoS 2, and Co-MoS 2 catalysts used for hydrodeoxygenation (HDO) of ethylene glycol upon variation of the partial pressures of H 2O and H 2S. The results show high water tolerance of the catalysts and highlight the importance of promotion and H 2S level during HDO. DFT calculations unraveled that the active edge of MoS 2 could be stabilized against SO exchanges by increasing the partial pressure of Hmore » 2S or by promotion with either Ni or Co. The Mo, NiMo, and CoMo catalysts of the present study were all active and fairly selective for ethylene glycol HDO at 400 °C, 27 bar H 2, and 550–2200 ppm H 2S, and conversions of ≈50–100%. The unpromoted Mo/MgAl 2O 4 catalyst had a lower stability and activity per gram catalyst than the promoted analogues. The NiMo and CoMo catalysts produced ethane, ethylene, and C1 cracking products with a C 2/C 1 ratio of 1.5–2.0 at 550 ppm H 2S. This ratio of HDO to cracking could be increased to ≈2 at 2200 ppm H 2S which also stabilized the activity. Removing H 2S from the feed caused severe catalyst deactivation. Both DFT and catalytic activity tests indicated that increasing the H 2S concentration increased the concentration of SH groups on the catalyst, which correspondingly activated and stabilized the catalytic HDO performance. In-situ XAS further supported that the catalysts were tolerant towards water when exposed to increasing water concentration with H2O/H2S ratios up to 300 at 400–450 °C. Raman spectroscopy and XAS showed that MoS2 was present in the prepared catalysts as small and highly dispersed particles, probably owing to a strong interaction with the support. Linear combination fitting (LCF) analysis of the X-ray absorption near edge structure (XANES) spectra obtained during in-situ sulfidation showed that Ni was sulfided faster than Mo and CoMo, and that Mo was sulfided faster when promoted with Ni. Extended X-ray absorption fine structure (EXAFS) results showed the presence of MoS 2 in all sulfided catalysts. Lastly, sulfided CoMo was present as a mixture of CoMoS and Co 9S 8, whereas sulfided NiMo was present as NiMoS.« less

Influence of H 2O and H 2S on the composition, activity, and stability of sulfided Mo, CoMo, and NiMo supported on MgAl 2O 4 for hydrodeoxygenation of ethylene glycol

DOE PAGES

Dabros, Trine Marie Hartmann; Gaur, Abhijeet; Pintos, Delfina Garcia; ...

2017-12-10

Here in this work, density functional theory (DFT), catalytic activity tests, and in-situ X-ray absorption spectroscopy (XAS) was performed to gain detailed insights into the activity and stability of MoS 2, Ni-MoS 2, and Co-MoS 2 catalysts used for hydrodeoxygenation (HDO) of ethylene glycol upon variation of the partial pressures of H 2O and H 2S. The results show high water tolerance of the catalysts and highlight the importance of promotion and H 2S level during HDO. DFT calculations unraveled that the active edge of MoS 2 could be stabilized against SO exchanges by increasing the partial pressure of Hmore » 2S or by promotion with either Ni or Co. The Mo, NiMo, and CoMo catalysts of the present study were all active and fairly selective for ethylene glycol HDO at 400 °C, 27 bar H 2, and 550–2200 ppm H 2S, and conversions of ≈50–100%. The unpromoted Mo/MgAl 2O 4 catalyst had a lower stability and activity per gram catalyst than the promoted analogues. The NiMo and CoMo catalysts produced ethane, ethylene, and C1 cracking products with a C 2/C 1 ratio of 1.5–2.0 at 550 ppm H 2S. This ratio of HDO to cracking could be increased to ≈2 at 2200 ppm H 2S which also stabilized the activity. Removing H 2S from the feed caused severe catalyst deactivation. Both DFT and catalytic activity tests indicated that increasing the H 2S concentration increased the concentration of SH groups on the catalyst, which correspondingly activated and stabilized the catalytic HDO performance. In-situ XAS further supported that the catalysts were tolerant towards water when exposed to increasing water concentration with H2O/H2S ratios up to 300 at 400–450 °C. Raman spectroscopy and XAS showed that MoS2 was present in the prepared catalysts as small and highly dispersed particles, probably owing to a strong interaction with the support. Linear combination fitting (LCF) analysis of the X-ray absorption near edge structure (XANES) spectra obtained during in-situ sulfidation showed that Ni was sulfided faster than Mo and CoMo, and that Mo was sulfided faster when promoted with Ni. Extended X-ray absorption fine structure (EXAFS) results showed the presence of MoS 2 in all sulfided catalysts. Lastly, sulfided CoMo was present as a mixture of CoMoS and Co 9S 8, whereas sulfided NiMo was present as NiMoS.« less

46 CFR 61.30-20 - Automatic control and safety tests.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Automatic control and safety tests. 61.30-20 Section 61... TESTS AND INSPECTIONS Tests and Inspections of Fired Thermal Fluid Heaters § 61.30-20 Automatic control and safety tests. Operational tests and checks of all safety and limit controls, combustion controls...

Controllable Grid Interface Test System | Energy Systems Integration

Science.gov Websites

Facility | NREL Controllable Grid Interface Test System Controllable Grid Interface Test System NREL's controllable grid interface (CGI) test system can reduce certification testing time and costs grid interface is the first test facility in the United States that has fault simulation capabilities

Tonopah Test Range - Index

Science.gov Websites

Capabilities Test Operations Center Test Director Range Control Track Control Communications Tracking Radars Us Range Videos/Photos Range Capabilities Test Operations Center Test Director Range Control Track Control Communications Tracking Radars Optical Systems Cinetheodolites Telescopes R&D Telescopes

14 CFR 33.87 - Endurance test.

Code of Federal Regulations, 2011 CFR

2011-01-01

... particular engine being tested. (2) Any automatic engine control that is part of the engine must control the engine during the endurance test except for operations where automatic control is normally overridden by manual control or where manual control is otherwise specified for a particular test run. (3) Except as...

14 CFR 33.87 - Endurance test.

Code of Federal Regulations, 2012 CFR

2012-01-01

... particular engine being tested. (2) Any automatic engine control that is part of the engine must control the engine during the endurance test except for operations where automatic control is normally overridden by manual control or where manual control is otherwise specified for a particular test run. (3) Except as...

21 CFR 58.107 - Test and control article handling.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Test and control article handling. 58.107 Section... GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.107 Test and control article handling. Procedures shall be established for a system for the handling of the test and...

21 CFR 58.107 - Test and control article handling.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Test and control article handling. 58.107 Section... GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.107 Test and control article handling. Procedures shall be established for a system for the handling of the test and...

21 CFR 58.107 - Test and control article handling.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Test and control article handling. 58.107 Section... GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.107 Test and control article handling. Procedures shall be established for a system for the handling of the test and...

21 CFR 58.107 - Test and control article handling.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Test and control article handling. 58.107 Section... GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.107 Test and control article handling. Procedures shall be established for a system for the handling of the test and...

49 CFR 192.471 - External corrosion control: Test leads.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false External corrosion control: Test leads. 192.471... Control § 192.471 External corrosion control: Test leads. (a) Each test lead wire must be connected to the pipeline so as to remain mechanically secure and electrically conductive. (b) Each test lead wire must be...

49 CFR 192.471 - External corrosion control: Test leads.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false External corrosion control: Test leads. 192.471... Control § 192.471 External corrosion control: Test leads. (a) Each test lead wire must be connected to the pipeline so as to remain mechanically secure and electrically conductive. (b) Each test lead wire must be...

49 CFR 192.471 - External corrosion control: Test leads.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false External corrosion control: Test leads. 192.471... Control § 192.471 External corrosion control: Test leads. (a) Each test lead wire must be connected to the pipeline so as to remain mechanically secure and electrically conductive. (b) Each test lead wire must be...

14 CFR 27.923 - Rotor drive system and control mechanism tests.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Rotor drive system and control mechanism....923 Rotor drive system and control mechanism tests. (a) Each part tested as prescribed in this section... affect test results may be conducted. (b) Each rotor drive system and control mechanism must be tested...

14 CFR 27.923 - Rotor drive system and control mechanism tests.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Rotor drive system and control mechanism....923 Rotor drive system and control mechanism tests. (a) Each part tested as prescribed in this section... affect test results may be conducted. (b) Each rotor drive system and control mechanism must be tested...

Instrument for controlling the application of mechanical loads to biological and bicompatible test subjects

DOEpatents

Lintilhac, Phillip M.; Vesecky, Thompson B.

1995-01-01

Apparatus and methods are disclosed facilitating the application of forces and measurement of dimensions of a test subject. In one arrangement the test subject is coupled to a forcing frame and controlled forces applied thereto. Force applied to the test subject is measured and controlled. A dimensional characteristic of the test subject, such as growth, is measured by a linear variable differential transformer. The growth measurement data can be used to control the force applied. The transducer module receives force and dimensional data from the forcing frame. The transducer module is a separate, microprocessor-based unit that communicates the test data to a controller unit that controls the application of force to the test subject and receives the test data from the transducer module for force control, storage, and/or communication to the user.

Instrument for controlling the application of mechanical loads to biological and bicompatible test subjects

DOEpatents

Lintilhac, P.M.; Vesecky, T.B.

1995-09-19

An apparatus and methods are disclosed facilitating the application of forces and measurement of dimensions of a test subject. In one arrangement the test subject is coupled to a forcing frame and controlled forces applied thereto. Force applied to the test subject is measured and controlled. A dimensional characteristic of the test subject, such as growth, is measured by a linear variable differential transformer. The growth measurement data can be used to control the force applied. The transducer module receives force and dimensional data from the forcing frame. The transducer module is a separate, microprocessor-based unit that communicates the test data to a controller unit that controls the application of force to the test subject and receives the test data from the transducer module for force control, storage, and/or communication to the user. 8 figs.

Cooperative system and method using mobile robots for testing a cooperative search controller

DOEpatents

Byrne, Raymond H.; Harrington, John J.; Eskridge, Steven E.; Hurtado, John E.

2002-01-01

A test system for testing a controller provides a way to use large numbers of miniature mobile robots to test a cooperative search controller in a test area, where each mobile robot has a sensor, a communication device, a processor, and a memory. A method of using a test system provides a way for testing a cooperative search controller using multiple robots sharing information and communicating over a communication network.

Early rehabilitation for severe acquired brain injury in intensive care unit: multicenter observational study.

PubMed

Bartolo, Michelangelo; Bargellesi, Stefano; Castioni, Carlo A; Bonaiuti, Donatella; Antenucci, Roberto; Benedetti, Angelo; Capuzzo, Valeria; Gamna, Federica; Radeschi, Giulio; Citerio, Giuseppe; Colombo, Carolina; Del Casale, Laura; Recubini, Elena; Toska, Saimir; Zanello, Marco; D'Aurizio, Carlo; Spina, Tullio; Del Gaudio, Alredo; Di Rienzo, Filomena; Intiso, Domenico; Dallocchio, Giulia; Felisatti, Giovanna; Lavezzi, Susanna; Zoppellari, Roberto; Gariboldi, Valentina; Lorini, Luca; Melizza, Giovanni; Molinero, Guido; Mandalà, Giorgio; Pignataro, Amedeo; Montis, Andrea; Napoleone, Alessandro; Pilia, Felicita; Pisu, Marina; Semerjian, Monica; Pagliaro, Giuseppina; Nardin, Lorella; Scarponi, Federico; Zampolini, Mauro; Zava, Raffaele; Massetti, Maria A; Piccolini, Carlo; Aloj, Fulvio; Antonelli, Sergio; Zucchella, Chiara

2016-02-01

The increased survival after a severe acquired brain injury (sABI) raise the problem of making most effective the treatments in Intensive Care Unit (ICU)/Neurointensive Care Unit (NICU), also integrating rehabilitation care. Despite previous studies reported that early mobilization in ICU was effective in preventing complications and reducing hospital stay, few studies addressed the rehabilitative management of sABI patients in ICU/NICU. To collect clinical and functional data about the early rehabilitative management of sABI patients during ICU/NICU stay. Prospective, observational, multicenter study. Fourteen facilities supplied by intensive neurorehabilitation units and ICU/NICUs. Consecutive sABI patients admitted to ICU/NICU. Patients were evaluated at admission and then every 3-5 days. Clinical, functional and rehabilitative data, including Glasgow Coma Scale (GCS), Disability Rating Scale (DRS), The Rancho Los Amigos Levels of Cognitive Functioning Scale (LCF), Early Rehabilitation Barthel Index (ERBI), Glasgow Outcome scale (GOS) and Functional Independence Measure (FIM) were collected. One hundred and two patients (F/M 44/58) were enrolled. The mean duration of ICU stay was 24.7±13.9 days and the first rehabilitative evaluation occurred after 8.7±8.8 days. Regular postural changes and multijoint mobilization were prescribed in 63.7% and 64.7% cases, respectively. The mean session duration was 38±11.5 minutes. Swallowing evaluation was performed in 14.7% patients, psychological support was provided to 12.7% of patients' caregivers, while 17.6% received a psycho-educational intervention, and 28.4% were involved in interdisciplinary team meetings. The main discharge destinations were Severe Acquired Brain Injury rehabilitation units for 43.7%, intensive neurorehabilitation units for 20.7%. Data showed that early rehabilitation was not diffusely performed in sABI subjects in ICU/NICU and rehabilitative interventions were variable; one-third of subjects were not referred to dedicated rehabilitation unit at discharge. The study stresses the need to spread and implement a rehabilitative culture also for critical ill patients due to neurological diseases.

Reference spectra of important adsorbed organic and inorganic phosphate binding forms for soil P speciation using synchrotron-based K-edge XANES spectroscopy.

PubMed

Prietzel, Jörg; Harrington, Gertraud; Häusler, Werner; Heister, Katja; Werner, Florian; Klysubun, Wantana

2016-03-01

Direct speciation of soil phosphorus (P) by linear combination fitting (LCF) of P K-edge XANES spectra requires a standard set of spectra representing all major P species supposed to be present in the investigated soil. Here, available spectra of free- and cation-bound inositol hexakisphosphate (IHP), representing organic P, and of Fe, Al and Ca phosphate minerals are supplemented with spectra of adsorbed P binding forms. First, various soil constituents assumed to be potentially relevant for P sorption were compared with respect to their retention efficiency for orthophosphate and IHP at P levels typical for soils. Then, P K-edge XANES spectra for orthophosphate and IHP retained by the most relevant constituents were acquired. The spectra were compared with each other as well as with spectra of Ca, Al or Fe orthophosphate and IHP precipitates. Orthophosphate and IHP were retained particularly efficiently by ferrihydrite, boehmite, Al-saturated montmorillonite and Al-saturated soil organic matter (SOM), but far less efficiently by hematite, Ca-saturated montmorillonite and Ca-saturated SOM. P retention by dolomite was negligible. Calcite retained a large portion of the applied IHP, but no orthophosphate. The respective P K-edge XANES spectra of orthophosphate and IHP adsorbed to ferrihydrite, boehmite, Al-saturated montmorillonite and Al-saturated SOM differ from each other. They also are different from the spectra of amorphous FePO4, amorphous or crystalline AlPO4, Ca phosphates and free IHP. Inclusion of reference spectra of orthophosphate as well as IHP adsorbed to P-retaining soil minerals in addition to spectra of free or cation-bound IHP, AlPO4, FePO4 and Ca phosphate minerals in linear combination fitting exercises results in improved fit quality and a more realistic soil P speciation. A standard set of P K-edge XANES spectra of the most relevant adsorbed P binding forms in soils is presented.

40 CFR 798.5200 - Mouse visible specific locus test.

Code of Federal Regulations, 2010 CFR

2010-07-01

... control groups. (4) Control groups—(i) Concurrent controls. The use of positive or spontaneous controls is... control groups. (ii) Test chemical vehicle, doses used and rationale for dose selection, toxicity data... SUBSTANCES CONTROL ACT (CONTINUED) HEALTH EFFECTS TESTING GUIDELINES Genetic Toxicity § 798.5200 Mouse...

40 CFR 798.5200 - Mouse visible specific locus test.

Code of Federal Regulations, 2013 CFR

2013-07-01

... control groups. (4) Control groups—(i) Concurrent controls. The use of positive or spontaneous controls is... control groups. (ii) Test chemical vehicle, doses used and rationale for dose selection, toxicity data... SUBSTANCES CONTROL ACT (CONTINUED) HEALTH EFFECTS TESTING GUIDELINES Genetic Toxicity § 798.5200 Mouse...

40 CFR 798.5200 - Mouse visible specific locus test.

Code of Federal Regulations, 2012 CFR

2012-07-01

... control groups. (4) Control groups—(i) Concurrent controls. The use of positive or spontaneous controls is... control groups. (ii) Test chemical vehicle, doses used and rationale for dose selection, toxicity data... SUBSTANCES CONTROL ACT (CONTINUED) HEALTH EFFECTS TESTING GUIDELINES Genetic Toxicity § 798.5200 Mouse...

40 CFR 798.5200 - Mouse visible specific locus test.

Code of Federal Regulations, 2014 CFR

2014-07-01

... control groups. (4) Control groups—(i) Concurrent controls. The use of positive or spontaneous controls is... control groups. (ii) Test chemical vehicle, doses used and rationale for dose selection, toxicity data... SUBSTANCES CONTROL ACT (CONTINUED) HEALTH EFFECTS TESTING GUIDELINES Genetic Toxicity § 798.5200 Mouse...

40 CFR 798.5200 - Mouse visible specific locus test.

Code of Federal Regulations, 2011 CFR

2011-07-01

... control groups. (4) Control groups—(i) Concurrent controls. The use of positive or spontaneous controls is... control groups. (ii) Test chemical vehicle, doses used and rationale for dose selection, toxicity data... SUBSTANCES CONTROL ACT (CONTINUED) HEALTH EFFECTS TESTING GUIDELINES Genetic Toxicity § 798.5200 Mouse...

On Restructurable Control System Theory

NASA Technical Reports Server (NTRS)

Athans, M.

1983-01-01

The state of stochastic system and control theory as it impacts restructurable control issues is addressed. The multivariable characteristics of the control problem are addressed. The failure detection/identification problem is discussed as a multi-hypothesis testing problem. Control strategy reconfiguration, static multivariable controls, static failure hypothesis testing, dynamic multivariable controls, fault-tolerant control theory, dynamic hypothesis testing, generalized likelihood ratio (GLR) methods, and adaptive control are discussed.

Control Room at the NACA’s Rocket Engine Test Facility

NASA Image and Video Library

1957-05-21

Test engineers monitor an engine firing from the control room of the Rocket Engine Test Facility at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The Rocket Engine Test Facility, built in the early 1950s, had a rocket stand designed to evaluate high-energy propellants and rocket engine designs. The facility was used to study numerous different types of rocket engines including the Pratt and Whitney RL-10 engine for the Centaur rocket and Rocketdyne’s F-1 and J-2 engines for the Saturn rockets. The Rocket Engine Test Facility was built in a ravine at the far end of the laboratory because of its use of the dangerous propellants such as liquid hydrogen and liquid fluorine. The control room was located in a building 1,600 feet north of the test stand to protect the engineers running the tests. The main control and instrument consoles were centrally located in the control room and surrounded by boards controlling and monitoring the major valves, pumps, motors, and actuators. A camera system at the test stand allowed the operators to view the tests, but the researchers were reliant on data recording equipment, sensors, and other devices to provide test data. The facility’s control room was upgraded several times over the years. Programmable logic controllers replaced the electro-mechanical control devices. The new controllers were programed to operate the valves and actuators controlling the fuel, oxidant, and ignition sequence according to a predetermined time schedule.

46 CFR 185.320 - Steering gear, controls, and communication system tests.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Steering gear, controls, and communication system tests... gear, controls, and communication system tests. The master of a vessel shall have examined and tested the steering gear, signaling whistle, propulsion controls, and communication systems of the vessel...

46 CFR 185.320 - Steering gear, controls, and communication system tests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Steering gear, controls, and communication system tests... gear, controls, and communication system tests. The master of a vessel shall have examined and tested the steering gear, signaling whistle, propulsion controls, and communication systems of the vessel...

46 CFR 61.30-20 - Automatic control and safety tests.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Automatic control and safety tests. 61.30-20 Section 61.30-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC... and safety tests. Operational tests and checks of all safety and limit controls, combustion controls...

46 CFR 61.30-20 - Automatic control and safety tests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Automatic control and safety tests. 61.30-20 Section 61.30-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC... and safety tests. Operational tests and checks of all safety and limit controls, combustion controls...

46 CFR 61.30-20 - Automatic control and safety tests.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Automatic control and safety tests. 61.30-20 Section 61.30-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC... and safety tests. Operational tests and checks of all safety and limit controls, combustion controls...

21 CFR 58.105 - Test and control article characterization.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Test and control article characterization. 58.105... GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.105 Test and control article characterization. (a) The identity, strength, purity, and composition or other...

21 CFR 58.105 - Test and control article characterization.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Test and control article characterization. 58.105... GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.105 Test and control article characterization. (a) The identity, strength, purity, and composition or other...

21 CFR 58.105 - Test and control article characterization.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Test and control article characterization. 58.105... GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.105 Test and control article characterization. (a) The identity, strength, purity, and composition or other...

21 CFR 58.105 - Test and control article characterization.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Test and control article characterization. 58.105... GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.105 Test and control article characterization. (a) The identity, strength, purity, and composition or other...

21 CFR 58.105 - Test and control article characterization.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Test and control article characterization. 58.105... GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.105 Test and control article characterization. (a) The identity, strength, purity, and composition or other...

7 CFR 58.928 - Quality control tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Quality control tests. 58.928 Section 58.928... Procedures § 58.928 Quality control tests. All dairy products and other ingredients shall be subject to inspection for quality and condition throughout each processing operation. Quality control tests shall be...

7 CFR 58.335 - Quality control tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Quality control tests. 58.335 Section 58.335... Procedures § 58.335 Quality control tests. All milk, cream and related products are subject to inspection for quality and condition throughout each processing operation. Quality control tests shall be made on flow...

77 FR 59023 - Preoperational Testing of Instrument and Control Air Systems

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-25

... NUCLEAR REGULATORY COMMISSION [NRC-2012-0065] Preoperational Testing of Instrument and Control Air..., ``Preoperational Testing of Instrument and Control Air Systems.'' This regulatory guide is being revised to address... instrument and control air systems (ICAS) to meet seismic requirement, ICAS air- dryer testing to meet dew...

46 CFR 185.320 - Steering gear, controls, and communication system tests.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Steering gear, controls, and communication system tests... gear, controls, and communication system tests. The master of a vessel shall have examined and tested the steering gear, signaling whistle, propulsion controls, and communication systems of the vessel...

Multi-axis transient vibration testing of space objects: Test philosophy, test facility, and control strategy

NASA Technical Reports Server (NTRS)

Lachenmayr, Georg

1992-01-01

IABG has been using various servohydraulic test facilities for many years for the reproduction of service loads and environmental loads on all kinds of test objects. For more than 15 years, a multi-axis vibration test facility has been under service, originally designed for earthquake simulation but being upgraded to the demands of space testing. First tests with the DFS/STM showed good reproduction accuracy and demonstrated the feasibility of transient vibration testing of space objects on a multi-axis hydraulic shaker. An approach to structural qualification is possible by using this test philosophy. It will be outlined and its obvious advantages over the state-of-the-art single-axis test will be demonstrated by example results. The new test technique has some special requirements to the test facility exceeding those of earthquake testing. Most important is the high reproduction accuracy demanded for a sophisticated control system. The state-of-the-art approach of analog closed-loop control circuits for each actuator combined with a static decoupling network and an off-line iterative waveform control is not able to meet all the demands. Therefore, the future over-all control system is implemented as hierarchical full digital closed-loop system on a highly parallel transputer network. The innermost layer is the digital actuator controller, the second one is the MDOF-control of the table movement. The outermost layer would be the off-line iterative waveform control, which is dedicated only to deal with the interaction of test table and test object or non-linear effects. The outline of the system will be presented.

Test Cases for the Benchmark Active Controls: Spoiler and Control Surface Oscillations and Flutter

NASA Technical Reports Server (NTRS)

Bennett, Robert M.; Scott, Robert C.; Wieseman, Carol D.

2000-01-01

As a portion of the Benchmark Models Program at NASA Langley, a simple generic model was developed for active controls research and was called BACT for Benchmark Active Controls Technology model. This model was based on the previously-tested Benchmark Models rectangular wing with the NACA 0012 airfoil section that was mounted on the Pitch and Plunge Apparatus (PAPA) for flutter testing. The BACT model had an upper surface spoiler, a lower surface spoiler, and a trailing edge control surface for use in flutter suppression and dynamic response excitation. Previous experience with flutter suppression indicated a need for measured control surface aerodynamics for accurate control law design. Three different types of flutter instability boundaries had also been determined for the NACA 0012/PAPA model, a classical flutter boundary, a transonic stall flutter boundary at angle of attack, and a plunge instability near M = 0.9. Therefore an extensive set of steady and control surface oscillation data was generated spanning the range of the three types of instabilities. This information was subsequently used to design control laws to suppress each flutter instability. There have been three tests of the BACT model. The objective of the first test, TDT Test 485, was to generate a data set of steady and unsteady control surface effectiveness data, and to determine the open loop dynamic characteristics of the control systems including the actuators. Unsteady pressures, loads, and transfer functions were measured. The other two tests, TDT Test 502 and TDT Test 5 18, were primarily oriented towards active controls research, but some data supplementary to the first test were obtained. Dynamic response of the flexible system to control surface excitation and open loop flutter characteristics were determined during Test 502. Loads were not measured during the last two tests. During these tests, a database of over 3000 data sets was obtained. A reasonably extensive subset of the data sets from the first two tests have been chosen for Test Cases for computational comparisons concentrating on static conditions and cases with harmonically oscillating control surfaces. Several flutter Test Cases from both tests have also been included. Some aerodynamic comparisons with the BACT data have been made using computational fluid dynamics codes at the Navier-Stokes level (and in the accompanying chapter SC). Some mechanical and active control studies have been presented. In this report several Test Cases are selected to illustrate trends for a variety of different conditions with emphasis on transonic flow effects. Cases for static angles of attack, static trailing-edge and upper-surface spoiler deflections are included for a range of conditions near those for the oscillation cases. Cases for trailing-edge control and upper-surface spoiler oscillations for a range of Mach numbers, angle of attack, and static control deflections are included. Cases for all three types of flutter instability are selected. In addition some cases are included for dynamic response measurements during forced oscillations of the controls on the flexible mount. An overview of the model and tests is given, and the standard formulary for these data is listed. Some sample data and sample results of calculations are presented. Only the static pressures and the first harmonic real and imaginary parts of the pressures are included in the data for the Test Cases, but digitized time histories have been archived. The data for the Test Cases are also available as separate electronic files.

Test Control Center

NASA Image and Video Library

2000-10-25

At the test observation periscope in the Test Control Center exhibit in StenniSphere at the John C. Stennis Space Center in Hancock County, Miss., visitors can observe a test of a Space Shuttle Main Engine exactly as test engineers might see it during a real engine test. The Test Control Center exhibit exactly simulates not only the test control environment, but also the procedure of testing a rocket engine. Designed to entertain while educating, StenniSphere includes informative dispays and exhibits from NASA's lead center for rocket propulsion and remote sensing applications. StenniSphere is open free of charge from 9 a.m. to 5 p.m. daily.

49 CFR 382.211 - Refusal to submit to a required alcohol or controlled substances test.

Code of Federal Regulations, 2014 CFR

2014-10-01

....211 Refusal to submit to a required alcohol or controlled substances test. No driver shall refuse to submit to a pre-employment controlled substance test required under § 382.301, a post-accident alcohol or... controlled substances test. 382.211 Section 382.211 Transportation Other Regulations Relating to...

49 CFR 382.211 - Refusal to submit to a required alcohol or controlled substances test.

Code of Federal Regulations, 2012 CFR

2012-10-01

....211 Refusal to submit to a required alcohol or controlled substances test. No driver shall refuse to submit to a pre-employment controlled substance test required under § 382.301, a post-accident alcohol or... controlled substances test. 382.211 Section 382.211 Transportation Other Regulations Relating to...

49 CFR 382.211 - Refusal to submit to a required alcohol or controlled substances test.

Code of Federal Regulations, 2010 CFR

2010-10-01

....211 Refusal to submit to a required alcohol or controlled substances test. No driver shall refuse to submit to a post-accident alcohol or controlled substances test required under § 382.303, a random... controlled substances test. 382.211 Section 382.211 Transportation Other Regulations Relating to...

49 CFR 382.211 - Refusal to submit to a required alcohol or controlled substances test.

Code of Federal Regulations, 2011 CFR

2011-10-01

....211 Refusal to submit to a required alcohol or controlled substances test. No driver shall refuse to submit to a post-accident alcohol or controlled substances test required under § 382.303, a random... controlled substances test. 382.211 Section 382.211 Transportation Other Regulations Relating to...

49 CFR 382.211 - Refusal to submit to a required alcohol or controlled substances test.

Code of Federal Regulations, 2013 CFR

2013-10-01

....211 Refusal to submit to a required alcohol or controlled substances test. No driver shall refuse to submit to a pre-employment controlled substance test required under § 382.301, a post-accident alcohol or... controlled substances test. 382.211 Section 382.211 Transportation Other Regulations Relating to...

7 CFR 58.523 - Laboratory and quality control tests.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 3 2014-01-01 2014-01-01 false Laboratory and quality control tests. 58.523 Section... Service 1 Operations and Operating Procedures § 58.523 Laboratory and quality control tests. (a) Quality control tests shall be made on samples as often as necessary to determine the shelf-life and stability of...

7 CFR 58.523 - Laboratory and quality control tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Laboratory and quality control tests. 58.523 Section... Service 1 Operations and Operating Procedures § 58.523 Laboratory and quality control tests. (a) Quality control tests shall be made on samples as often as necessary to determine the shelf-life and stability of...

7 CFR 58.523 - Laboratory and quality control tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 3 2013-01-01 2013-01-01 false Laboratory and quality control tests. 58.523 Section... Service 1 Operations and Operating Procedures § 58.523 Laboratory and quality control tests. (a) Quality control tests shall be made on samples as often as necessary to determine the shelf-life and stability of...

7 CFR 58.523 - Laboratory and quality control tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Laboratory and quality control tests. 58.523 Section... Service 1 Operations and Operating Procedures § 58.523 Laboratory and quality control tests. (a) Quality control tests shall be made on samples as often as necessary to determine the shelf-life and stability of...

7 CFR 58.523 - Laboratory and quality control tests.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 3 2012-01-01 2012-01-01 false Laboratory and quality control tests. 58.523 Section... Service 1 Operations and Operating Procedures § 58.523 Laboratory and quality control tests. (a) Quality control tests shall be made on samples as often as necessary to determine the shelf-life and stability of...

40 CFR 792.47 - Facilities for handling test, control, and reference substances.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 32 2014-07-01 2014-07-01 false Facilities for handling test, control... § 792.47 Facilities for handling test, control, and reference substances. (a) As necessary to prevent contamination or mixups, there shall be separate areas for: (1) Receipt and storage of the test, control, and...

40 CFR 792.47 - Facilities for handling test, control, and reference substances.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Facilities for handling test, control... § 792.47 Facilities for handling test, control, and reference substances. (a) As necessary to prevent contamination or mixups, there shall be separate areas for: (1) Receipt and storage of the test, control, and...

40 CFR 792.47 - Facilities for handling test, control, and reference substances.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 33 2013-07-01 2013-07-01 false Facilities for handling test, control... § 792.47 Facilities for handling test, control, and reference substances. (a) As necessary to prevent contamination or mixups, there shall be separate areas for: (1) Receipt and storage of the test, control, and...

40 CFR 792.47 - Facilities for handling test, control, and reference substances.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 33 2012-07-01 2012-07-01 false Facilities for handling test, control... § 792.47 Facilities for handling test, control, and reference substances. (a) As necessary to prevent contamination or mixups, there shall be separate areas for: (1) Receipt and storage of the test, control, and...

49 CFR 192.471 - External corrosion control: Test leads.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Test leads. 192.471... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Requirements for Corrosion Control § 192.471 External corrosion control: Test leads. (a) Each test lead wire must be connected to the...

49 CFR 192.471 - External corrosion control: Test leads.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false External corrosion control: Test leads. 192.471... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Requirements for Corrosion Control § 192.471 External corrosion control: Test leads. (a) Each test lead wire must be connected to the...

Flight Test of the F/A-18 Active Aeroelastic Wing Airplane

NASA Technical Reports Server (NTRS)

Clarke, Robert; Allen, Michael J.; Dibley, Ryan P.; Gera, Joseph; Hodgkinson, John

2005-01-01

Successful flight-testing of the Active Aeroelastic Wing airplane was completed in March 2005. This program, which started in 1996, was a joint activity sponsored by NASA, Air Force Research Laboratory, and industry contractors. The test program contained two flight test phases conducted in early 2003 and early 2005. During the first phase of flight test, aerodynamic models and load models of the wing control surfaces and wing structure were developed. Design teams built new research control laws for the Active Aeroelastic Wing airplane using these flight-validated models; and throughout the final phase of flight test, these new control laws were demonstrated. The control laws were designed to optimize strategies for moving the wing control surfaces to maximize roll rates in the transonic and supersonic flight regimes. Control surface hinge moments and wing loads were constrained to remain within hydraulic and load limits. This paper describes briefly the flight control system architecture as well as the design approach used by Active Aeroelastic Wing project engineers to develop flight control system gains. Additionally, this paper presents flight test techniques and comparison between flight test results and predictions.

40 CFR 799.1700 - Fluoroalkenes.

Code of Federal Regulations, 2013 CFR

2013-07-01

... fraction (S-9) of livers from rats pretreated with Aroclor 1254. (iv) Test method—Control groups. Positive... control and diluting gas. (v) Test method—Test chemicals. The test should be designed to have a... the negative control. Cytotoxicity shall be determined after treatment with the test substance both in...

40 CFR 799.1700 - Fluoroalkenes.

Code of Federal Regulations, 2014 CFR

2014-07-01

... fraction (S-9) of livers from rats pretreated with Aroclor 1254. (iv) Test method—Control groups. Positive... control and diluting gas. (v) Test method—Test chemicals. The test should be designed to have a... the negative control. Cytotoxicity shall be determined after treatment with the test substance both in...

40 CFR 799.1700 - Fluoroalkenes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... fraction (S-9) of livers from rats pretreated with Aroclor 1254. (iv) Test method—Control groups. Positive... control and diluting gas. (v) Test method—Test chemicals. The test should be designed to have a... the negative control. Cytotoxicity shall be determined after treatment with the test substance both in...

40 CFR 799.1700 - Fluoroalkenes.

Code of Federal Regulations, 2012 CFR

2012-07-01

... fraction (S-9) of livers from rats pretreated with Aroclor 1254. (iv) Test method—Control groups. Positive... control and diluting gas. (v) Test method—Test chemicals. The test should be designed to have a... the negative control. Cytotoxicity shall be determined after treatment with the test substance both in...

40 CFR 799.1700 - Fluoroalkenes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... fraction (S-9) of livers from rats pretreated with Aroclor 1254. (iv) Test method—Control groups. Positive... control and diluting gas. (v) Test method—Test chemicals. The test should be designed to have a... the negative control. Cytotoxicity shall be determined after treatment with the test substance both in...

29 CFR 1910.7 - Definition and requirements for a nationally recognized testing laboratory.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., written testing procedures, and calibration and quality control programs) to perform: (i) Testing and... test standards; or (ii) Experimental testing and examining of equipment and materials for workplace..., labeled, or accepted, the following controls or services: (i) Implements control procedures for...

Effect of a Mobile Web App on Kidney Transplant Candidates' Knowledge About Increased Risk Donor Kidneys: A Randomized Controlled Trial.

PubMed

Gordon, Elisa J; Sohn, Min-Woong; Chang, Chih-Hung; McNatt, Gwen; Vera, Karina; Beauvais, Nicole; Warren, Emily; Mannon, Roslyn B; Ison, Michael G

2017-06-01

Kidney transplant candidates (KTCs) must provide informed consent to accept kidneys from increased risk donors (IRD), but poorly understand them. We conducted a multisite, randomized controlled trial to evaluate the efficacy of a mobile Web application, Inform Me, for increasing knowledge about IRDs. Kidney transplant candidates undergoing transplant evaluation at 2 transplant centers were randomized to use Inform Me after routine transplant education (intervention) or routine transplant education alone (control). Computer adaptive learning method reinforced learning by embedding educational material, and initial (test 1) and additional test questions (test 2) into each chapter. Knowledge (primary outcome) was assessed in person after education (tests 1 and 2), and 1 week later by telephone (test 3). Controls did not receive test 2. Willingness to accept an IRD kidney (secondary outcome) was assessed after tests 1 and 3. Linear regression test 1 knowledge scores were used to test the significance of Inform Me exposure after controlling for covariates. Multiple imputation was used for intention-to-treat analysis. Two hundred eighty-eight KTCs participated. Intervention participants had higher test 1 knowledge scores (mean difference, 6.61; 95% confidence interval [95% CI], 5.37-7.86) than control participants, representing a 44% higher score than control participants' scores. Intervention participants' knowledge scores increased with educational reinforcement (test 2) compared with control arm test 1 scores (mean difference, 9.50; 95% CI, 8.27-10.73). After 1 week, intervention participants' knowledge remained greater than controls' knowledge (mean difference, 3.63; 95% CI, 2.49-4.78) (test 3). Willingness to accept an IRD kidney did not differ between study arms at tests 1 and 3. Inform Me use was associated with greater KTC knowledge about IRD kidneys above routine transplant education alone.

Proportional and Integral Thermal Control System for Large Scale Heating Tests

NASA Technical Reports Server (NTRS)

Fleischer, Van Tran

2015-01-01

The National Aeronautics and Space Administration Armstrong Flight Research Center (Edwards, California) Flight Loads Laboratory is a unique national laboratory that supports thermal, mechanical, thermal/mechanical, and structural dynamics research and testing. A Proportional Integral thermal control system was designed and implemented to support thermal tests. A thermal control algorithm supporting a quartz lamp heater was developed based on the Proportional Integral control concept and a linearized heating process. The thermal control equations were derived and expressed in terms of power levels, integral gain, proportional gain, and differences between thermal setpoints and skin temperatures. Besides the derived equations, user's predefined thermal test information generated in the form of thermal maps was used to implement the thermal control system capabilities. Graphite heater closed-loop thermal control and graphite heater open-loop power level were added later to fulfill the demand for higher temperature tests. Verification and validation tests were performed to ensure that the thermal control system requirements were achieved. This thermal control system has successfully supported many milestone thermal and thermal/mechanical tests for almost a decade with temperatures ranging from 50 F to 3000 F and temperature rise rates from -10 F/s to 70 F/s for a variety of test articles having unique thermal profiles and test setups.

Remotely Piloted Vehicles for Experimental Flight Control Testing

NASA Technical Reports Server (NTRS)

Motter, Mark A.; High, James W.

2009-01-01

A successful flight test and training campaign of the NASA Flying Controls Testbed was conducted at Naval Outlying Field, Webster Field, MD during 2008. Both the prop and jet-powered versions of the subscale, remotely piloted testbeds were used to test representative experimental flight controllers. These testbeds were developed by the Subsonic Fixed Wing Project s emphasis on new flight test techniques. The Subsonic Fixed Wing Project is under the Fundamental Aeronautics Program of NASA's Aeronautics Research Mission Directorate (ARMD). The purpose of these testbeds is to quickly and inexpensively evaluate advanced concepts and experimental flight controls, with applications to adaptive control, system identification, novel control effectors, correlation of subscale flight tests with wind tunnel results, and autonomous operations. Flight tests and operator training were conducted during four separate series of tests during April, May, June and August 2008. Experimental controllers were engaged and disengaged during fully autonomous flight in the designated test area. Flaps and landing gear were deployed by commands from the ground control station as unanticipated disturbances. The flight tests were performed NASA personnel with support from the Maritime Unmanned Development and Operations (MUDO) team of the Naval Air Warfare Center, Aircraft Division

Flight Test of an Adaptive Controller and Simulated Failure/Damage on the NASA NF-15B

NASA Technical Reports Server (NTRS)

Buschbacher, Mark; Maliska, Heather

2006-01-01

The method of flight-testing the Intelligent Flight Control System (IFCS) Second Generation (Gen-2) project on the NASA NF-15B is herein described. The Gen-2 project objective includes flight-testing a dynamic inversion controller augmented by a direct adaptive neural network to demonstrate performance improvements in the presence of simulated failure/damage. The Gen-2 objectives as implemented on the NASA NF-15B created challenges for software design, structural loading limitations, and flight test operations. Simulated failure/damage is introduced by modifying control surface commands, therefore requiring structural loads measurements. Flight-testing began with the validation of a structural loads model. Flight-testing of the Gen-2 controller continued, using test maneuvers designed in a sequenced approach. Success would clear the new controller with respect to dynamic response, simulated failure/damage, and with adaptation on and off. A handling qualities evaluation was conducted on the capability of the Gen-2 controller to restore aircraft response in the presence of a simulated failure/damage. Control room monitoring of loads sensors, flight dynamics, and controller adaptation, in addition to postflight data comparison to the simulation, ensured a safe methodology of buildup testing. Flight-testing continued without major incident to accomplish the project objectives, successfully uncovering strengths and weaknesses of the Gen-2 control approach in flight.

A boundary-optimized rejection region test for the two-sample binomial problem.

PubMed

Gabriel, Erin E; Nason, Martha; Fay, Michael P; Follmann, Dean A

2018-03-30

Testing the equality of 2 proportions for a control group versus a treatment group is a well-researched statistical problem. In some settings, there may be strong historical data that allow one to reliably expect that the control proportion is one, or nearly so. While one-sample tests or comparisons to historical controls could be used, neither can rigorously control the type I error rate in the event the true control rate changes. In this work, we propose an unconditional exact test that exploits the historical information while controlling the type I error rate. We sequentially construct a rejection region by first maximizing the rejection region in the space where all controls have an event, subject to the constraint that our type I error rate does not exceed α for any true event rate; then with any remaining α we maximize the additional rejection region in the space where one control avoids the event, and so on. When the true control event rate is one, our test is the most powerful nonrandomized test for all points in the alternative space. When the true control event rate is nearly one, we demonstrate that our test has equal or higher mean power, averaging over the alternative space, than a variety of well-known tests. For the comparison of 4 controls and 4 treated subjects, our proposed test has higher power than all comparator tests. We demonstrate the properties of our proposed test by simulation and use our method to design a malaria vaccine trial. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

U.S. Coast Guard SARSAT Final Evaluation Report. Volume II. Appendices.

DOT National Transportation Integrated Search

1987-03-01

Contents: Controlled Tests; Controlled Test Error Analysis, Processing of Westwind Data; Exercises and Homing Tests; Further Analysis of Controlled Tests; Sar Case Analysis Tables; Narratives of Real Distress Cases; RCC Response Scenarios; Workload A...

46 CFR 61.30-20 - Automatic control and safety tests.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Automatic control and safety tests. 61.30-20 Section 61.30-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC TESTS AND INSPECTIONS Tests and Inspections of Fired Thermal Fluid Heaters § 61.30-20 Automatic control and safety tests. Operational tests and check...

Thermal Vacuum Test of GLAS Propylene Loop Heat Pipe Development Model

NASA Technical Reports Server (NTRS)

Baker, Charles; Butler, Dan; Ku, Jentung; Kaya, Tarik; Nikitkin, Michael

2000-01-01

This paper presents viewgraphs on Thermal Vacuum Tests of the GLAS (Geoscience Laser Altimeter System) Propylene Loop Heat Pipe Development Model. The topics include: 1) Flight LHP System (Laser); 2) Test Design and Objectives; 3) DM (Development Model) LHP (Loop Heat Pipe) Test Design; 4) Starter Heater and Coupling Blocks; 5) CC Control Heaters and PRT; 6) Heater Plates (Shown in Reflux Mode); 7) Startup Tests; 8) CC Control Heater Power Tests for CC Temperature Control; and 9) Control Temperature Stability.

40 CFR Appendix C to Part 300 - Swirling Flask Dispersant Effectiveness Test, Revised Standard Dispersant Toxicity Test, and...

Code of Federal Regulations, 2014 CFR

2014-07-01

..., if two groups (product A and a non-nutrient control) are tested at each of three points in time (day... groups: Group 1: Non-nutrient Control Group 2: Nutrient Control Group 3: Test Product 4.7.4.2The raw data... different from those of both the nutrient control (group 2) and the non-nutrient control (group 1) for those...

40 CFR Appendix C to Part 300 - Swirling Flask Dispersant Effectiveness Test, Revised Standard Dispersant Toxicity Test, and...

Code of Federal Regulations, 2011 CFR

2011-07-01

..., if two groups (product A and a non-nutrient control) are tested at each of three points in time (day... groups: Group 1: Non-nutrient Control Group 2: Nutrient Control Group 3: Test Product 4.7.4.2The raw data... different from those of both the nutrient control (group 2) and the non-nutrient control (group 1) for those...

40 CFR Appendix C to Part 300 - Swirling Flask Dispersant Effectiveness Test, Revised Standard Dispersant Toxicity Test, and...

Code of Federal Regulations, 2013 CFR

2013-07-01

..., if two groups (product A and a non-nutrient control) are tested at each of three points in time (day... groups: Group 1: Non-nutrient Control Group 2: Nutrient Control Group 3: Test Product 4.7.4.2The raw data... different from those of both the nutrient control (group 2) and the non-nutrient control (group 1) for those...

40 CFR Appendix C to Part 300 - Swirling Flask Dispersant Effectiveness Test, Revised Standard Dispersant Toxicity Test, and...

Code of Federal Regulations, 2010 CFR

2010-07-01

..., if two groups (product A and a non-nutrient control) are tested at each of three points in time (day... groups: Group 1: Non-nutrient Control Group 2: Nutrient Control Group 3: Test Product 4.7.4.2The raw data... different from those of both the nutrient control (group 2) and the non-nutrient control (group 1) for those...

5. "UNDERGROUND CONTROL ROOM AT TEST STAND 1A, DIRECTORATE OF ...

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

5. "UNDERGROUND CONTROL ROOM AT TEST STAND 1-A, DIRECTORATE OF MISSILE CAPTIVE TEST, EDWARDS AFB, 15 JAN 58, 3097.58." Two men working in the control room. Photo no. "3097 58; G-AFFTC 15 JAN 58, T.S. 1-A Control". - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Control Center, Test Area 1-115, near Altair & Saturn Boulevards, Boron, Kern County, CA

7 CFR 58.733 - Quality control tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Quality control tests. 58.733 Section 58.733... Procedures § 58.733 Quality control tests. (a) Chemical analyses. The following chemical analyses shall be... pasteurization by means of the phosphatase test, as well as any other tests necessary to assure good quality...

7 CFR 58.733 - Quality control tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Quality control tests. 58.733 Section 58.733... Procedures § 58.733 Quality control tests. (a) Chemical analyses. The following chemical analyses shall be... pasteurization by means of the phosphatase test, as well as any other tests necessary to assure good quality...

40 CFR 1037.510 - Duty-cycle exhaust testing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... part 86. For cruise cycle testing of vehicles equipped with cruise control, use the vehicle's cruise... CONTROLS CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR VEHICLES Test and Modeling Procedures § 1037.510...: variable speeds for the transient test and constant speeds for the cruise tests. None of these cycles...

40 CFR 1037.510 - Duty-cycle exhaust testing.

Code of Federal Regulations, 2012 CFR

2012-07-01

... part 86. For cruise cycle testing of vehicles equipped with cruise control, use the vehicle's cruise... CONTROLS CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR VEHICLES Test and Modeling Procedures § 1037.510...: variable speeds for the transient test and constant speeds for the cruise tests. None of these cycles...

40 CFR 1037.510 - Duty-cycle exhaust testing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... part 86. For cruise cycle testing of vehicles equipped with cruise control, use the vehicle's cruise... CONTROLS CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR VEHICLES Test and Modeling Procedures § 1037.510...: variable speeds for the transient test and constant speeds for the cruise tests. None of these cycles...

10 CFR 72.162 - Test control.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 2 2011-01-01 2011-01-01 false Test control. 72.162 Section 72.162 Energy NUCLEAR... Test control. The licensee, applicant for a license, certificate holder, and applicant for a CoC shall establish a test program to ensure that all testing, required to demonstrate that the structures, systems...

10 CFR 71.123 - Test control.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 2 2011-01-01 2011-01-01 false Test control. 71.123 Section 71.123 Energy NUCLEAR....123 Test control. The licensee, certificate holder, and applicant for a CoC shall establish a test... satisfactorily in service is identified and performed in accordance with written test procedures that incorporate...

Cancer Screening: How Do Screening Tests Become Standard Tests?

MedlinePlus

... more groups. The people in one group (the control group ) may be given a standard screening test (if one exists) or no screening test. The ... for the human papillomavirus (HPV) and those who test negative for HPV. The ... Case-control studies Case-control studies are like cohort studies ...

International Space Station alpha remote manipulator system workstation controls test report

NASA Astrophysics Data System (ADS)

Ehrenstrom, William A.; Swaney, Colin; Forrester, Patrick

1994-05-01

Previous development testing for the space station remote manipulator system workstation controls determined the need for hardware controls for the emergency stop, brakes on/off, and some camera functions. This report documents the results of an evaluation to further determine control implementation requirements, requested by the Canadian Space Agency (CSA), to close outstanding review item discrepancies. This test was conducted at the Johnson Space Center's Space Station Mockup and Trainer Facility in Houston, Texas, with nine NASA astronauts and one CSA astronaut as operators. This test evaluated camera iris and focus, back-up drive, latching end effector release, and autosequence controls using several types of hardware and software implementations. Recommendations resulting from the testing included providing guarded hardware buttons to prevent accidental actuation, providing autosequence controls and back-up drive controls on a dedicated hardware control panel, and that 'latch on/latch off', or on-screen software, controls not be considered. Generally, the operators preferred hardware controls although other control implementations were acceptable. The results of this evaluation will be used along with further testing to define specific requirements for the workstation design.

International Space Station alpha remote manipulator system workstation controls test report

NASA Technical Reports Server (NTRS)

Ehrenstrom, William A.; Swaney, Colin; Forrester, Patrick

1994-01-01

Previous development testing for the space station remote manipulator system workstation controls determined the need for hardware controls for the emergency stop, brakes on/off, and some camera functions. This report documents the results of an evaluation to further determine control implementation requirements, requested by the Canadian Space Agency (CSA), to close outstanding review item discrepancies. This test was conducted at the Johnson Space Center's Space Station Mockup and Trainer Facility in Houston, Texas, with nine NASA astronauts and one CSA astronaut as operators. This test evaluated camera iris and focus, back-up drive, latching end effector release, and autosequence controls using several types of hardware and software implementations. Recommendations resulting from the testing included providing guarded hardware buttons to prevent accidental actuation, providing autosequence controls and back-up drive controls on a dedicated hardware control panel, and that 'latch on/latch off', or on-screen software, controls not be considered. Generally, the operators preferred hardware controls although other control implementations were acceptable. The results of this evaluation will be used along with further testing to define specific requirements for the workstation design.

21 CFR 58.47 - Facilities for handling test and control articles.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Facilities for handling test and control articles... for handling test and control articles. (a) As necessary to prevent contamination or mixups, there shall be separate areas for: (1) Receipt and storage of the test and control articles. (2) Mixing of the...

21 CFR 58.47 - Facilities for handling test and control articles.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Facilities for handling test and control articles... for handling test and control articles. (a) As necessary to prevent contamination or mixups, there shall be separate areas for: (1) Receipt and storage of the test and control articles. (2) Mixing of the...

21 CFR 58.47 - Facilities for handling test and control articles.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Facilities for handling test and control articles... for handling test and control articles. (a) As necessary to prevent contamination or mixups, there shall be separate areas for: (1) Receipt and storage of the test and control articles. (2) Mixing of the...

21 CFR 58.47 - Facilities for handling test and control articles.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Facilities for handling test and control articles... for handling test and control articles. (a) As necessary to prevent contamination or mixups, there shall be separate areas for: (1) Receipt and storage of the test and control articles. (2) Mixing of the...

Testing jumps via false discovery rate control.

PubMed

Yen, Yu-Min

2013-01-01

Many recently developed nonparametric jump tests can be viewed as multiple hypothesis testing problems. For such multiple hypothesis tests, it is well known that controlling type I error often makes a large proportion of erroneous rejections, and such situation becomes even worse when the jump occurrence is a rare event. To obtain more reliable results, we aim to control the false discovery rate (FDR), an efficient compound error measure for erroneous rejections in multiple testing problems. We perform the test via the Barndorff-Nielsen and Shephard (BNS) test statistic, and control the FDR with the Benjamini and Hochberg (BH) procedure. We provide asymptotic results for the FDR control. From simulations, we examine relevant theoretical results and demonstrate the advantages of controlling the FDR. The hybrid approach is then applied to empirical analysis on two benchmark stock indices with high frequency data.

Flight test of a full authority Digital Electronic Engine Control system in an F-15 aircraft

NASA Technical Reports Server (NTRS)

Barrett, W. J.; Rembold, J. P.; Burcham, F. W.; Myers, L.

1981-01-01

The Digital Electronic Engine Control (DEEC) system considered is a relatively low cost digital full authority control system containing selectively redundant components and fault detection logic with capability for accommodating faults to various levels of operational capability. The DEEC digital control system is built around a 16-bit, 1.2 microsecond cycle time, CMOS microprocessor, microcomputer system with approximately 14 K of available memory. Attention is given to the control mode, component bench testing, closed loop bench testing, a failure mode and effects analysis, sea-level engine testing, simulated altitude engine testing, flight testing, the data system, cockpit, and real time display.

Odor Control Test Report of the Urine Containment Bag (UCB) for Orion Utilization

NASA Technical Reports Server (NTRS)

Casper, Stephanie; Williams, Nichole M. M.

2010-01-01

The purpose of this report is to summarize the conclusions for the odor control test of the Urine Containment Bag (UCB), P/N SDD46107234-306 in an environment simulating a space craft capsule. JSC 65891, Odor Control Test Plan of the Urine Containment Bag (UCB) for Orion Utilization, documents the test plan. The details of the test set-up and data reduction are detailed in the WSTF test report for this test WSTF #10-44500, Odor Control Test Plan of the Urine Containment Bag (UCB) for Orion Utilization,. This document outlines the project conclusions and forward plans with regard to trash containment for Constellation.

The role of self-control strength in the development of state anxiety in test situations.

PubMed

Englert, C; Bertrams, A

2013-06-01

Self-control strength may affect state anxiety because emotion regulation is impaired in individuals whose self-control strength has been temporarily depleted. Increases in state anxiety were expected to be larger for participants with depleted compared to nondepleted self-control strength, and trait test anxiety should predict increases in state anxiety more strongly if self-control strength is depleted. In a sample of 76 university students, trait test anxiety was assessed, self-control strength experimentally manipulated, and state anxiety measured before and after the announcement of a test. State anxiety increased after the announcement. Trait test anxiety predicted increases in state anxiety only in students with depleted self-control strength, suggesting that increased self-control strength may be useful for coping with anxiety.

Use of Patients With Diarrhea Who Test Negative for Rotavirus as Controls to Estimate Rotavirus Vaccine Effectiveness Through Case-Control Studies.

PubMed

Tate, Jacqueline E; Patel, Manish M; Cortese, Margaret M; Payne, Daniel C; Lopman, Benjamin A; Yen, Catherine; Parashar, Umesh D

2016-05-01

Case-control studies are often performed to estimate postlicensure vaccine effectiveness (VE), but the enrollment of controls can be challenging, time-consuming, and costly. We evaluated whether children enrolled in the same hospital-based diarrheal surveillance used to identify rotavirus cases but who test negative for rotavirus (test-negative controls) can be considered a suitable alternative to nondiarrheal hospital or community-based control groups (traditional controls). We compared calculated VE estimates as a function of varying values of true VE, attack rates of rotavirus and nonrotavirus diarrhea in the population, and sensitivity and specificity of the rotavirus enzyme immunoasssay. We also searched the literature to identify rotavirus VE studies that used traditional and test-negative control groups and compared VE estimates obtained using the different control groups. Assuming a 1% attack rate for severe rotavirus diarrhea, a 3% attack rate for severe nonrotavirus diarrhea in the population, a test sensitivity of 96%, and a specificity of 100%, the calculated VE estimates using both the traditional and test-negative control groups closely approximated the true VE for all values from 30% to 100%. As true VE decreased, the traditional case-control approach slightly overestimated the true VE and the test-negative case-control approach slightly underestimated this estimate, but the absolute difference was only ±0.2 percentage points. Field VE estimates from 10 evaluations that used both traditional and test-negative control groups were similar regardless of control group used. The use of rotavirus test-negative controls offers an efficient and cost-effective approach to estimating rotavirus VE through case-control studies. Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

An Overview of Controls and Flying Qualities Technology on the F/A-18 High Alpha Research Vehicle

NASA Technical Reports Server (NTRS)

Pahle, Joseph W.; Wichman, Keith D.; Foster, John V.; Bundick, W. Thomas

1996-01-01

The NASA F/A-18 High Alpha Research Vehicle (HARV) has been the flight test bed of a focused technology effort to significantly increase maneuvering capability at high angles of attack. Development and flight test of control law design methodologies, handling qualities metrics, performance guidelines, and flight evaluation maneuvers are described. The HARV has been modified to include two research control effectors, thrust vectoring, and actuated forebody strakes in order to provide increased control power at high angles of attack. A research flight control system has been used to provide a flexible, easily modified capability for high-angle-of-attack research controls. Different control law design techniques have been implemented and flight-tested, including eigenstructure assignment, variable gain output feedback, pseudo controls, and model-following. Extensive piloted simulation has been used to develop nonlinear performance guide-lines and handling qualities criteria for high angles of attack. This paper reviews the development and evaluation of technologies useful for high-angle-of-attack control. Design, development, and flight test of the research flight control system, control laws, flying qualities specifications, and flight test maneuvers are described. Flight test results are used to illustrate some of the lessons learned during flight test and handling qualities evaluations.

40 CFR Appendix A to Subpart S of... - Calibrations, Adjustments and Quality Control

Code of Federal Regulations, 2012 CFR

2012-07-01

... average of the pre-test and post-test ambient background levels shall be compared to the permissible...—Calibrations, Adjustments and Quality Control (I) Steady-State Test Equipment States may opt to use transient emission test equipment for steady-state tests and follow the quality control requirements in paragraph (II...

40 CFR Appendix A to Subpart S of... - Calibrations, Adjustments and Quality Control

Code of Federal Regulations, 2010 CFR

2010-07-01

... average of the pre-test and post-test ambient background levels shall be compared to the permissible...—Calibrations, Adjustments and Quality Control (I) Steady-State Test Equipment States may opt to use transient emission test equipment for steady-state tests and follow the quality control requirements in paragraph (II...

40 CFR Appendix A to Subpart S of... - Calibrations, Adjustments and Quality Control

Code of Federal Regulations, 2011 CFR

2011-07-01

... average of the pre-test and post-test ambient background levels shall be compared to the permissible...—Calibrations, Adjustments and Quality Control (I) Steady-State Test Equipment States may opt to use transient emission test equipment for steady-state tests and follow the quality control requirements in paragraph (II...

40 CFR Appendix A to Subpart S of... - Calibrations, Adjustments and Quality Control

Code of Federal Regulations, 2013 CFR

2013-07-01

... average of the pre-test and post-test ambient background levels shall be compared to the permissible...—Calibrations, Adjustments and Quality Control (I) Steady-State Test Equipment States may opt to use transient emission test equipment for steady-state tests and follow the quality control requirements in paragraph (II...

40 CFR Appendix A to Subpart S of... - Calibrations, Adjustments and Quality Control

Code of Federal Regulations, 2014 CFR

2014-07-01

... average of the pre-test and post-test ambient background levels shall be compared to the permissible...—Calibrations, Adjustments and Quality Control (I) Steady-State Test Equipment States may opt to use transient emission test equipment for steady-state tests and follow the quality control requirements in paragraph (II...

Seminar on Understanding Digital Control and Analysis in Vibration Test Systems

NASA Technical Reports Server (NTRS)

1975-01-01

The advantages of the digital methods over the analog vibration methods are demonstrated. The following topics are covered: (1) methods of computer-controlled random vibration and reverberation acoustic testing, (2) methods of computer-controlled sinewave vibration testing, and (3) methods of computer-controlled shock testing. General algorithms are described in the form of block diagrams and flow diagrams.

7 CFR 58.928 - Quality control tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... quality test shall be made to determine product stability. ... 7 Agriculture 3 2013-01-01 2013-01-01 false Quality control tests. 58.928 Section 58.928... Procedures § 58.928 Quality control tests. All dairy products and other ingredients shall be subject to...

7 CFR 58.928 - Quality control tests.

Code of Federal Regulations, 2012 CFR

2012-01-01

... quality test shall be made to determine product stability. ... 7 Agriculture 3 2012-01-01 2012-01-01 false Quality control tests. 58.928 Section 58.928... Procedures § 58.928 Quality control tests. All dairy products and other ingredients shall be subject to...

Verification test results of Apollo stabilization and control systems during undocked operations

NASA Technical Reports Server (NTRS)

Copeland, E. L.; Haken, R. L.

1974-01-01

The results are presented of analysis and simulation testing of both the Skylark 1 reaction control system digital autopilot (RCS DAP) and the thrust vector control (TVC) autopilot for use during the undocked portions of the Apollo/Soyuz Test Project Mission. The RCS DAP testing was performed using the Skylab Functional Simulator (SLFS), a digital computer program capable of simulating the Apollo and Skylab autopilots along with vehicle dynamics including bending and sloshing. The model is used to simulate three-axis automatic maneuvers along with pilot controlled manual maneuvers using the RCS DAP. The TVC autopilot was tested in two parts. A classical stability analysis was performed on the vehicle considering the effects of structural bending and sloshing when under control of the TVC autopilot. The time response of the TVC autopilot was tested using the SLFS. Results indicate that adequate performance stability margins can be expected for the CSM/DM configuration when under the control of the Apollo control systems tested.

A Method for Implementing Force-Limited Vibration Control

NASA Technical Reports Server (NTRS)

Worth, Daniel B.

1997-01-01

NASA/GSFC has implemented force-limited vibration control on a controller which can only accept one profile. The method uses a personal computer based digital signal processing board to convert force and/or moment signals into what appears to he an acceleration signal to the controller. This technique allows test centers with older controllers to use the latest force-limited control techniques for random vibration testing. The paper describes the method, hardware, and test procedures used. An example from a test performed at NASA/GSFC is used as a guide.

Fatigue data for polyether ether ketone (PEEK) under fully-reversed cyclic loading

PubMed Central

Shrestha, Rakish; Simsiriwong, Jutima; Shamsaei, Nima

2016-01-01

In this article, the data obtained from the uniaxial fully-reversed fatigue experiments conducted on polyether ether ketone (PEEK), a semi-crystalline thermoplastic, are presented. The tests were performed in either strain-controlled or load-controlled mode under various levels of loading. The data are categorized into four subsets according to the type of tests, including (1) strain-controlled fatigue tests with adjusted frequency to obtain the nominal temperature rise of the specimen surface, (2) strain-controlled fatigue tests with various frequencies, (3) load-controlled fatigue tests without step loadings, and (4) load-controlled fatigue tests with step loadings. Accompanied data for each test include the fatigue life, the maximum (peak) and minimum (valley) stress–strain responses for each cycle, and the hysteresis stress–strain responses for each collected cycle in a logarithmic increment. A brief description of the experimental method is also given. PMID:26937465

Fatigue data for polyether ether ketone (PEEK) under fully-reversed cyclic loading.

PubMed

Shrestha, Rakish; Simsiriwong, Jutima; Shamsaei, Nima

2016-03-01

In this article, the data obtained from the uniaxial fully-reversed fatigue experiments conducted on polyether ether ketone (PEEK), a semi-crystalline thermoplastic, are presented. The tests were performed in either strain-controlled or load-controlled mode under various levels of loading. The data are categorized into four subsets according to the type of tests, including (1) strain-controlled fatigue tests with adjusted frequency to obtain the nominal temperature rise of the specimen surface, (2) strain-controlled fatigue tests with various frequencies, (3) load-controlled fatigue tests without step loadings, and (4) load-controlled fatigue tests with step loadings. Accompanied data for each test include the fatigue life, the maximum (peak) and minimum (valley) stress-strain responses for each cycle, and the hysteresis stress-strain responses for each collected cycle in a logarithmic increment. A brief description of the experimental method is also given.

Summary of NASA/DOE Aileron-Control Development Program for Wind Turbines

NASA Technical Reports Server (NTRS)

Miller, D. R.

1986-01-01

The development of aileron-control for wind turbines is discussed. Selected wind tunnel test results and full-scale rotor test results are presented for various types of ailerons. Finally, the current status of aileron-control development is discussed. Aileron-control was considered as a method of rotor control for use on wind turbines based on its potential to reduce rotor weight and cost. Following an initial feasibility study, a 20 percent chord aileron-control rotor was fabricated and tested on the NASA/DOE Mod-0 experimental wind turbine. Results from these tests indicated that the 20 percent chord ailerons regulated power and provided overspeed protection, but only over a very limited windspeed range. The next aileron-control rotor to be tested on the Mod-0 had 38 percent chord ailerons and test results showed these ailerons provided overspeed protection and power regulation over the Mod-0's entire operational windspeed range.

40 CFR 792.107 - Test, control, and reference substance handling.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Test, control, and reference substance handling. 792.107 Section 792.107 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) GOOD LABORATORY PRACTICE STANDARDS Test, Control, and Reference...

Road load simulator tests of the Gould phase 1 functional model silicon controlled rectifier ac motor controller for electric vehicles

NASA Astrophysics Data System (ADS)

Gourash, F.

1984-02-01

The test results for a functional model ac motor controller for electric vehicles and a three-phase induction motor which were dynamically tested on the Lewis Research Center road load simulator are presented. Results show that the controller has the capability to meet the SAE-J227a D cycle test schedule and to accelerate a 1576-kg (3456-lb) simulated vehicle to a cruise speed of 88.5 km/hr (55 mph). Combined motor controller efficiency is 72 percent and the power inverter efficiency alone is 89 percent for the cruise region of the D cycle. Steady state test results for motoring, regeneration, and thermal data obtained by operating the simulator as a conventional dynamometer are in agreement with the contractor's previously reported data. The regeneration test results indicate that a reduction in energy requirements for urban driving cycles is attainable with regenerative braking. Test results and data in this report serve as a data base for further development of ac motor controllers and propulsion systems for electric vehicles. The controller uses state-of-the-art silicon controlled rectifier (SCR) power semiconductors and microprocessor-based logic and control circuitry. The controller was developed by Gould Laboratories under a Lewis contract for the Department of Energy's Electric and Hybrid Vehicle program.

Road load simulator tests of the Gould phase 1 functional model silicon controlled rectifier ac motor controller for electric vehicles

NASA Technical Reports Server (NTRS)

Gourash, F.

1984-01-01

The test results for a functional model ac motor controller for electric vehicles and a three-phase induction motor which were dynamically tested on the Lewis Research Center road load simulator are presented. Results show that the controller has the capability to meet the SAE-J227a D cycle test schedule and to accelerate a 1576-kg (3456-lb) simulated vehicle to a cruise speed of 88.5 km/hr (55 mph). Combined motor controller efficiency is 72 percent and the power inverter efficiency alone is 89 percent for the cruise region of the D cycle. Steady state test results for motoring, regeneration, and thermal data obtained by operating the simulator as a conventional dynamometer are in agreement with the contractor's previously reported data. The regeneration test results indicate that a reduction in energy requirements for urban driving cycles is attainable with regenerative braking. Test results and data in this report serve as a data base for further development of ac motor controllers and propulsion systems for electric vehicles. The controller uses state-of-the-art silicon controlled rectifier (SCR) power semiconductors and microprocessor-based logic and control circuitry. The controller was developed by Gould Laboratories under a Lewis contract for the Department of Energy's Electric and Hybrid Vehicle program.

B-52 control configured vehicles: Flight test results

NASA Technical Reports Server (NTRS)

Arnold, J. I.; Murphy, F. B.

1976-01-01

Recently completed B-52 Control Configured Vehicles (CCV) flight testing is summarized, and results are compared to analytical predictions. Results are presented for five CCV system concepts: ride control, maneuver load control, flutter mode control, augmented stability, and fatigue reduction. Test results confirm analytical predictions and show that CCV system concepts achieve performance goals when operated individually or collectively.

Comparison of two control groups for estimation of oral cholera vaccine effectiveness using a case-control study design.

PubMed

Franke, Molly F; Jerome, J Gregory; Matias, Wilfredo R; Ternier, Ralph; Hilaire, Isabelle J; Harris, Jason B; Ivers, Louise C

2017-10-13

Case-control studies to quantify oral cholera vaccine effectiveness (VE) often rely on neighbors without diarrhea as community controls. Test-negative controls can be easily recruited and may minimize bias due to differential health-seeking behavior and recall. We compared VE estimates derived from community and test-negative controls and conducted bias-indicator analyses to assess potential bias with community controls. From October 2012 through November 2016, patients with acute watery diarrhea were recruited from cholera treatment centers in rural Haiti. Cholera cases had a positive stool culture. Non-cholera diarrhea cases (test-negative controls and non-cholera diarrhea cases for bias-indicator analyses) had a negative culture and rapid test. Up to four community controls were matched to diarrhea cases by age group, time, and neighborhood. Primary analyses included 181 cholera cases, 157 non-cholera diarrhea cases, 716 VE community controls and 625 bias-indicator community controls. VE for self-reported vaccination with two doses was consistent across the two control groups, with statistically significant VE estimates ranging from 72 to 74%. Sensitivity analyses revealed similar, though somewhat attenuated estimates for self-reported two dose VE. Bias-indicator estimates were consistently less than one, with VE estimates ranging from 19 to 43%, some of which were statistically significant. OCV estimates from case-control analyses using community and test-negative controls were similar. While bias-indicator analyses suggested possible over-estimation of VE estimates using community controls, test-negative analyses suggested this bias, if present, was minimal. Test-negative controls can be a valid low-cost and time-efficient alternative to community controls for OCV effectiveness estimation and may be especially relevant in emergency situations. Copyright © 2017. Published by Elsevier Ltd.

Measuring indigenous photosynthetic organisms to detect chemical warefare agents in water

DOEpatents

Greenbaum, Elias; Sanders, Charlene A.

2005-11-15

A method of testing water to detect the presence of a chemical or biological warfare agent is disclosed. The method is carried out by establishing control data by providing control water containing indigenous organisms but substantially free of a chemical and a biological warfare agent. Then measuring photosynthetic activity of the control water with a fluorometer to obtain control data to compare with test data to detect the presence of the chemical or agent. The test data is gathered by providing test water comprising the same indigenous organisms as contained in the control water. Further, the test water is suspected of containing the chemical or agent to be tested for. Photosynthetic activity is also measured by fluorescence induction in the test water using a fluorometer.

Unit Testing for Command and Control Systems

NASA Technical Reports Server (NTRS)

Alexander, Joshua

2018-01-01

Unit tests were created to evaluate the functionality of a Data Generation and Publication tool for a command and control system. These unit tests are developed to constantly evaluate the tool and ensure it functions properly as the command and control system grows in size and scope. Unit tests are a crucial part of testing any software project and are especially instrumental in the development of a command and control system. They save resources, time and costs associated with testing, and catch issues before they become increasingly difficult and costly. The unit tests produced for the Data Generation and Publication tool to be used in a command and control system assure the users and stakeholders of its functionality and offer assurances which are vital in the launching of spacecraft safely.

CSM digital autopilot testing in support of ASTP experiments control requirements

NASA Technical Reports Server (NTRS)

Rue, D. L.

1975-01-01

Results are presented of CSM digital autopilot (DAP) testing. The testing was performed to demonstrate and evaluate control modes which are currently planned or could be considered for use in support of experiments on the ASTP mission. The testing was performed on the Lockheed Guidance, Navigation, and Control System Functional Simulator (GNCFS). This simulator, which was designed to test the Apollo and Skylab DAP control system, has been used extensively and is a proven tool for CSM DAP analysis.

Complete Host Range Testing on Common Reed with Potential Biological Control Agents and Investigation into Biological Control for Flowering Rush

DTIC Science & Technology

2016-07-01

ER D C/ EL C R- 16 -5 Aquatic Plant Control Research Program Complete Host Range Testing on Common Reed with Potential Biological...client/default. Aquatic Plant Control Research Program ERDC/EL CR-16-5 July 2016 Complete Host Range Testing on Common Reed with Potential...and started with sequential no-choice oviposition tests. So far, no eggs were found on any of the 22 test plants offered. The authors also found the

Molecular Mechanism for Prostate Cancer Resistance to the Anti-tumor Activity of Vitamin D

DTIC Science & Technology

2006-11-01

point where each curve crossed the threshold line (Ct) using the following equation : Rel. value = 2[Ct(control) Ct(test)]test gene / 2[Ct(control...by hypermethylation in human pancreatic cancer. J Hum Genet 2005;50:159–67. 41. Armes JE, Hammet F, de Silva M, et al. Candidate tumor-suppressor...line (Ct) using the equation : Rel. Value = 2 - [Ct(control) – Ct(test)]test gene/ 2 -[Ct(control) – Ct(test)]housekeeping gene [22]. Reactions were

Actuated forebody strake controls for the F-18 high alpha research vehicle

NASA Technical Reports Server (NTRS)

Murri, Daniel G.; Shah, Gautam H.; Dicarlo, Daniel J.; Trilling, Todd W.

1993-01-01

A series of ground-based studies have been conducted to develop actuated forebody strake controls for flight test evaluations using the NASA F-18 High-Alpha Research Vehicle. The actuated forebody strake concept has been designed to provide increased levels of yaw control at high angles of attack where conventional rudders become ineffective. Results are presented from tests conducted with the flight-test strake design, including static and dynamic wind-tunnel tests, transonic wind-tunnel tests, full-scale wind-tunnel tests, pressure surveys, and flow visualization tests. Results from these studies show that a pair of conformal actuated forebody strakes applied to the F-18 HARV can provide a powerful and precise yaw control device at high angles of attack. The preparations for flight testing are described, including the fabrication of flight hardware and the development of aircraft flight control laws. The primary objectives of the flight tests are to provide flight validation of the groundbased studies and to evaluate the use of this type of control to enhance fighter aircraft maneuverability.

Full-Scaled Advanced Systems Testbed: Ensuring Success of Adaptive Control Research Through Project Lifecycle Risk Mitigation

NASA Technical Reports Server (NTRS)

Pavlock, Kate M.

2011-01-01

The National Aeronautics and Space Administration's Dryden Flight Research Center completed flight testing of adaptive controls research on the Full-Scale Advance Systems Testbed (FAST) in January of 2011. The research addressed technical challenges involved with reducing risk in an increasingly complex and dynamic national airspace. Specific challenges lie with the development of validated, multidisciplinary, integrated aircraft control design tools and techniques to enable safe flight in the presence of adverse conditions such as structural damage, control surface failures, or aerodynamic upsets. The testbed is an F-18 aircraft serving as a full-scale vehicle to test and validate adaptive flight control research and lends a significant confidence to the development, maturation, and acceptance process of incorporating adaptive control laws into follow-on research and the operational environment. The experimental systems integrated into FAST were designed to allow for flexible yet safe flight test evaluation and validation of modern adaptive control technologies and revolve around two major hardware upgrades: the modification of Production Support Flight Control Computers (PSFCC) and integration of two, fourth-generation Airborne Research Test Systems (ARTS). Post-hardware integration verification and validation provided the foundation for safe flight test of Nonlinear Dynamic Inversion and Model Reference Aircraft Control adaptive control law experiments. To ensure success of flight in terms of cost, schedule, and test results, emphasis on risk management was incorporated into early stages of design and flight test planning and continued through the execution of each flight test mission. Specific consideration was made to incorporate safety features within the hardware and software to alleviate user demands as well as into test processes and training to reduce human factor impacts to safe and successful flight test. This paper describes the research configuration, experiment functionality, overall risk mitigation, flight test approach and results, and lessons learned of adaptive controls research of the Full-Scale Advanced Systems Testbed.

40 CFR 160.107 - Test, control, and reference substance handling.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Test, control, and reference substance handling. 160.107 Section 160.107 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS GOOD LABORATORY PRACTICE STANDARDS Test, Control, and Reference Substances § 160.107 Test...

40 CFR 799.9120 - TSCA acute dermal toxicity.

Code of Federal Regulations, 2011 CFR

2011-07-01

... identification number. A system to randomly assign animals to test groups and control groups is required. (E... source of test animals. (2) Method of randomization in assigning animals to test and control groups. (3... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

40 CFR 799.9120 - TSCA acute dermal toxicity.

Code of Federal Regulations, 2010 CFR

2010-07-01

... identification number. A system to randomly assign animals to test groups and control groups is required. (E... source of test animals. (2) Method of randomization in assigning animals to test and control groups. (3... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

40 CFR 799.9120 - TSCA acute dermal toxicity.

Code of Federal Regulations, 2012 CFR

2012-07-01

... identification number. A system to randomly assign animals to test groups and control groups is required. (E... source of test animals. (2) Method of randomization in assigning animals to test and control groups. (3... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

40 CFR 799.9120 - TSCA acute dermal toxicity.

Code of Federal Regulations, 2014 CFR

2014-07-01

... identification number. A system to randomly assign animals to test groups and control groups is required. (E... source of test animals. (2) Method of randomization in assigning animals to test and control groups. (3... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

40 CFR 799.9120 - TSCA acute dermal toxicity.

Code of Federal Regulations, 2013 CFR

2013-07-01

... identification number. A system to randomly assign animals to test groups and control groups is required. (E... source of test animals. (2) Method of randomization in assigning animals to test and control groups. (3... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

10 CFR 71.123 - Test control.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Test control. 71.123 Section 71.123 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE MATERIAL Quality Assurance § 71.123 Test control. The licensee, certificate holder, and applicant for a CoC shall establish a test...

10 CFR 71.123 - Test control.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 2 2013-01-01 2013-01-01 false Test control. 71.123 Section 71.123 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE MATERIAL Quality Assurance § 71.123 Test control. The licensee, certificate holder, and applicant for a CoC shall establish a test...

10 CFR 71.123 - Test control.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 2 2014-01-01 2014-01-01 false Test control. 71.123 Section 71.123 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE MATERIAL Quality Assurance § 71.123 Test control. The licensee, certificate holder, and applicant for a CoC shall establish a test...

Low-Speed Stability and Control Test of a "Double-Bubble" Transport Configuration

NASA Technical Reports Server (NTRS)

Vicroy, Dan D.

2017-01-01

A test in the Langley 12-Foot Low-Speed Tunnel was conducted as a risk mitigation effort to quickly obtain some low-speed stability and control data on a "double-bubble" or D8 transport configuration. The test also tested some configuration design trades. A 5-percent scale model was tested with stabilizer, elevator, rudder and aileron control deflections. This report summarizes the test results.

49 CFR 192.469 - External corrosion control: Test stations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Test stations. 192.469... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Requirements for Corrosion Control § 192.469 External corrosion control: Test stations. Each pipeline under cathodic protection...

49 CFR 192.469 - External corrosion control: Test stations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false External corrosion control: Test stations. 192.469... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Requirements for Corrosion Control § 192.469 External corrosion control: Test stations. Each pipeline under cathodic protection...

49 CFR 192.469 - External corrosion control: Test stations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false External corrosion control: Test stations. 192.469... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Requirements for Corrosion Control § 192.469 External corrosion control: Test stations. Each pipeline under cathodic protection...

49 CFR 192.469 - External corrosion control: Test stations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false External corrosion control: Test stations. 192.469... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Requirements for Corrosion Control § 192.469 External corrosion control: Test stations. Each pipeline under cathodic protection...

49 CFR 192.469 - External corrosion control: Test stations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false External corrosion control: Test stations. 192.469... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Requirements for Corrosion Control § 192.469 External corrosion control: Test stations. Each pipeline under cathodic protection...

NASA Langley Distributed Propulsion VTOL Tilt-Wing Aircraft Testing, Modeling, Simulation, Control, and Flight Test Development

NASA Technical Reports Server (NTRS)

Rothhaar, Paul M.; Murphy, Patrick C.; Bacon, Barton J.; Gregory, Irene M.; Grauer, Jared A.; Busan, Ronald C.; Croom, Mark A.

2014-01-01

Control of complex Vertical Take-Off and Landing (VTOL) aircraft traversing from hovering to wing born flight mode and back poses notoriously difficult modeling, simulation, control, and flight-testing challenges. This paper provides an overview of the techniques and advances required to develop the GL-10 tilt-wing, tilt-tail, long endurance, VTOL aircraft control system. The GL-10 prototype's unusual and complex configuration requires application of state-of-the-art techniques and some significant advances in wind tunnel infrastructure automation, efficient Design Of Experiments (DOE) tunnel test techniques, modeling, multi-body equations of motion, multi-body actuator models, simulation, control algorithm design, and flight test avionics, testing, and analysis. The following compendium surveys key disciplines required to develop an effective control system for this challenging vehicle in this on-going effort.

Space Station Freedom Environmental Control and Life Support System (ECLSS) phase 3 simplified integrated test trace contaminant control subsystem performance

NASA Technical Reports Server (NTRS)

Perry, J. L.

1990-01-01

Space Station Freedom environmental control and life support system testing has been conducted at Marshall Space Flight Center since 1986. The phase 3 simplified integrated test (SIT) conducted from July 30, 1989, through August 11, 1989, tested an integrated air revitalization system. During this test, the trace contaminant control subsystem (TCCS) was directly integrated with the bleed stream from the carbon dioxide reduction subsystem. The TCCS performed as expected with minor anomalies. The test set the basis for further characterizing the TCCS performance as part of advance air revitalization system configurations.

Real time test bed development for power system operation, control and cyber security

NASA Astrophysics Data System (ADS)

Reddi, Ram Mohan

The operation and control of the power system in an efficient way is important in order to keep the system secure, reliable and economical. With advancements in smart grid, several new algorithms have been developed for improved operation and control. These algorithms need to be extensively tested and validated in real time before applying to the real electric power grid. This work focuses on the development of a real time test bed for testing and validating power system control algorithms, hardware devices and cyber security vulnerability. The test bed developed utilizes several hardware components including relays, phasor measurement units, phasor data concentrator, programmable logic controllers and several software tools. Current work also integrates historian for power system monitoring and data archiving. Finally, two different power system test cases are simulated to demonstrate the applications of developed test bed. The developed test bed can also be used for power system education.

46 CFR 160.133-15 - Production inspections, tests, quality control, and conformance of release mechanisms.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 6 2012-10-01 2012-10-01 false Production inspections, tests, quality control, and..., tests, quality control, and conformance of release mechanisms. (a) Unless the Commandant directs.... The Commandant may prescribe additional production tests and inspections necessary to maintain quality...

46 CFR 160.133-15 - Production inspections, tests, quality control, and conformance of release mechanisms.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 6 2013-10-01 2013-10-01 false Production inspections, tests, quality control, and..., tests, quality control, and conformance of release mechanisms. (a) Unless the Commandant directs.... The Commandant may prescribe additional production tests and inspections necessary to maintain quality...

49 CFR 236.588 - Periodic test.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Inspection and Tests; Locomotive § 236.588 Periodic test. Except as provided in § 236.586, periodic test of the automatic train stop, train control, or cab signal apparatus...

40 CFR 160.47 - Facilities for handling test, control, and reference substances.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the test systems and shall be adequate to preserve the identity, strength, purity, and stability of... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Facilities for handling test, control... for handling test, control, and reference substances. (a) As necessary to prevent contamination or...

40 CFR 160.47 - Facilities for handling test, control, and reference substances.

Code of Federal Regulations, 2013 CFR

2013-07-01

... the test systems and shall be adequate to preserve the identity, strength, purity, and stability of... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Facilities for handling test, control... for handling test, control, and reference substances. (a) As necessary to prevent contamination or...

40 CFR 160.47 - Facilities for handling test, control, and reference substances.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the test systems and shall be adequate to preserve the identity, strength, purity, and stability of... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Facilities for handling test, control... for handling test, control, and reference substances. (a) As necessary to prevent contamination or...

40 CFR 160.47 - Facilities for handling test, control, and reference substances.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the test systems and shall be adequate to preserve the identity, strength, purity, and stability of... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Facilities for handling test, control... for handling test, control, and reference substances. (a) As necessary to prevent contamination or...

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, MIRATECH CORPORATIONM GECO 3001 AIR/FUEL RATIO CONTROLLER

EPA Science Inventory

Details on the verification test design, measurement test procedures, and Quality assurance/Quality Control (QA/QC) procedures can be found in the test plan titled Testing and Quality Assurance Plan, MIRATECH Corporation GECO 3100 Air/Fuel Ratio Controller (SRI 2001). It can be d...

40 CFR 792.105 - Test, control, and reference substance characterization.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Test, control, and reference substance... shall be determined by the testing facility or the sponsor before the experimental start date. The stability of the test, control or reference substance shall be determined before the experimental start date...

Effectiveness of urban stormwater control measures in a 100-acre test site

EPA Science Inventory

Kansas City, Missouri chose a test area (100 acres) and a control area (80 acres) to test the effectiveness of urban stormwater control (SCM) deployment in conjunction with the USEPA, University of Alabama, University of Missouri-Kansas City and TetraTech. Both the test and cont...

46 CFR 160.170-15 - Production inspections, tests, quality control, and conformance of release mechanisms.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Production inspections, tests, quality control, and..., quality control, and conformance of release mechanisms. (a) Unless the Commandant directs otherwise, an... prescribe additional production tests and inspections necessary to maintain quality control and to monitor...

46 CFR 160.170-15 - Production inspections, tests, quality control, and conformance of release mechanisms.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 6 2012-10-01 2012-10-01 false Production inspections, tests, quality control, and..., quality control, and conformance of release mechanisms. (a) Unless the Commandant directs otherwise, an... prescribe additional production tests and inspections necessary to maintain quality control and to monitor...

46 CFR 160.133-15 - Production inspections, tests, quality control, and conformance of release mechanisms.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Production inspections, tests, quality control, and..., quality control, and conformance of release mechanisms. (a) Unless the Commandant directs otherwise, an... prescribe additional production tests and inspections necessary to maintain quality control and to monitor...

46 CFR 160.170-15 - Production inspections, tests, quality control, and conformance of release mechanisms.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 6 2013-10-01 2013-10-01 false Production inspections, tests, quality control, and..., quality control, and conformance of release mechanisms. (a) Unless the Commandant directs otherwise, an... prescribe additional production tests and inspections necessary to maintain quality control and to monitor...

7 CFR 58.442 - Laboratory and quality control tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Laboratory and quality control tests. 58.442 Section... Service 1 Operations and Operating Procedures § 58.442 Laboratory and quality control tests. (a) Chemical... Methods or by other methods giving equivalent results. (b) Weight or volume control. Representative...

7 CFR 58.442 - Laboratory and quality control tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Laboratory and quality control tests. 58.442 Section... Service 1 Operations and Operating Procedures § 58.442 Laboratory and quality control tests. (a) Chemical... Methods or by other methods giving equivalent results. (b) Weight or volume control. Representative...

14 CFR 417.305 - Command control system testing.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Command control system testing. 417.305..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety System § 417.305 Command control system testing. (a) General. (1) A command control system, including its subsystems and components must undergo...

14 CFR 417.305 - Command control system testing.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Command control system testing. 417.305..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety System § 417.305 Command control system testing. (a) General. (1) A command control system, including its subsystems and components must undergo...

14 CFR 417.305 - Command control system testing.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Command control system testing. 417.305..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety System § 417.305 Command control system testing. (a) General. (1) A command control system, including its subsystems and components must undergo...

14 CFR 417.305 - Command control system testing.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Command control system testing. 417.305..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety System § 417.305 Command control system testing. (a) General. (1) A command control system, including its subsystems and components must undergo...

14 CFR 417.305 - Command control system testing.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Command control system testing. 417.305..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety System § 417.305 Command control system testing. (a) General. (1) A command control system, including its subsystems and components must undergo...

Scaled Composites' Doug Shane examines the screen of his ground control station during tests in New Mexico. Shane used this configuration as the ground control station to remotely pilot the Proteus aircraft during a NASA sponsored series of tests.

NASA Image and Video Library

2002-03-13

Scaled Composites' Doug Shane examines the screen of his ground control station during tests in New Mexico. Shane used this configuration as the ground control station to remotely pilot the Proteus aircraft during a NASA sponsored series of tests.

JPL control/structure interaction test bed real-time control computer architecture

NASA Technical Reports Server (NTRS)

Briggs, Hugh C.

1989-01-01

The Control/Structure Interaction Program is a technology development program for spacecraft that exhibit interactions between the control system and structural dynamics. The program objectives include development and verification of new design concepts - such as active structure - and new tools - such as combined structure and control optimization algorithm - and their verification in ground and possibly flight test. A focus mission spacecraft was designed based upon a space interferometer and is the basis for design of the ground test article. The ground test bed objectives include verification of the spacecraft design concepts, the active structure elements and certain design tools such as the new combined structures and controls optimization tool. In anticipation of CSI technology flight experiments, the test bed control electronics must emulate the computation capacity and control architectures of space qualifiable systems as well as the command and control networks that will be used to connect investigators with the flight experiment hardware. The Test Bed facility electronics were functionally partitioned into three units: a laboratory data acquisition system for structural parameter identification and performance verification; an experiment supervisory computer to oversee the experiment, monitor the environmental parameters and perform data logging; and a multilevel real-time control computing system. The design of the Test Bed electronics is presented along with hardware and software component descriptions. The system should break new ground in experimental control electronics and is of interest to anyone working in the verification of control concepts for large structures.

Advanced on-the-Job Training System: Readiness Test Plan

DTIC Science & Technology

1990-05-01

entry of completions into an airman’s ATR. To determine if a specific test objective has been met, a "measure of effectiveness" (MOE) must be de ...Evaluasto acces control Test 4 Supervisor s control Test 5 Training Manager s control Test 6 GenerateATR Test 7 Generat OPTR Test 8 Generate I TR Teot 9...Trainer, Supervisor , Evaluator, Training MMnger) into only properly authorized AOTS components. This critical function Is therefore related to each of the

Flight tests for the assessment of task performance and control activity

NASA Technical Reports Server (NTRS)

Pausder, H. J.; Hummes, D.

1982-01-01

The tests were performed with the helicopters BO 105 and UH-1D. Closely connected with tactical demands the six test pilots' task was to minimize the time and the altitude over the obstacles. The data reduction yields statistical evaluation parameters describing the control activity of the pilots and the achieved task performance. The results are shown in form of evaluation diagrams. Additionally dolphin tests with varied control strategy were performed to get more insight into the influence of control techniques. From these test results recommendations can be derived to emphasize the direct force control and to reduce the collective to pitch crosscoupling for the dolphin.

A Rejection Principle for Sequential Tests of Multiple Hypotheses Controlling Familywise Error Rates

PubMed Central

BARTROFF, JAY; SONG, JINLIN

2015-01-01

We present a unifying approach to multiple testing procedures for sequential (or streaming) data by giving sufficient conditions for a sequential multiple testing procedure to control the familywise error rate (FWER). Together we call these conditions a “rejection principle for sequential tests,” which we then apply to some existing sequential multiple testing procedures to give simplified understanding of their FWER control. Next the principle is applied to derive two new sequential multiple testing procedures with provable FWER control, one for testing hypotheses in order and another for closed testing. Examples of these new procedures are given by applying them to a chromosome aberration data set and to finding the maximum safe dose of a treatment. PMID:26985125

Atopy patch test reactions to house dust mites in patients with scabies.

PubMed

Taşkapan, Oktay; Harmanyeri, Yavuz

2005-01-01

It is well known that the house dust and the scabies mites are related phylogenetically. We therefore performed atopy patch tests with house dust mite antigens (Dermatophagoides pteronyssinus (Dp) and/or Dermatophagoides farinae (Df)) in scabies patients without atopy and healthy controls. We studied 25 men with active scabies and 25 healthy controls. Skin prick tests with standardized house dust mite extract were performed for all patients and controls. An intradermal test procedure was carried out in skin prick test-negative patients, and for controls showing positive atopy patch test to Dp and/or Df. While atopy patch tests were performed directly in all healthy controls, patients with scabies were first treated and on the next day, atopy patch tests were performed. Twenty-two of 25 patients with scabies (88%) had skin prick test and/or intradermal test positivity against house dust mites, whereas 17/25 patients (68%) had atopy patch test positivity against house dust mites (Dp and/or Df). There was no statistically significant difference between skin prick test and/or intradermal test positivity and atopy patch test positivity in a regression analysis (p=0.222). The only statistically significant correlation was between atopy patch test positivity and the extent of scabies involvement (p<0.05). Only few of the healthy controls had positive tests. In this study, we have shown that a positive atopy patch test to house dust mite antigens is not specific for patients with atopic dermatitis, but also occurs in scabies patients without a history of atopic dermatitis.

Controllability Analysis for Multirotor Helicopter Rotor Degradation and Failure

NASA Astrophysics Data System (ADS)

Du, Guang-Xun; Quan, Quan; Yang, Binxian; Cai, Kai-Yuan

2015-05-01

This paper considers the controllability analysis problem for a class of multirotor systems subject to rotor failure/wear. It is shown that classical controllability theories of linear systems are not sufficient to test the controllability of the considered multirotors. Owing to this, an easy-to-use measurement index is introduced to assess the available control authority. Based on it, a new necessary and sufficient condition for the controllability of multirotors is derived. Furthermore, a controllability test procedure is approached. The proposed controllability test method is applied to a class of hexacopters with different rotor configurations and different rotor efficiency parameters to show its effectiveness. The analysis results show that hexacopters with different rotor configurations have different fault-tolerant capabilities. It is therefore necessary to test the controllability of the multirotors before any fault-tolerant control strategies are employed.

AST Critical Propulsion and Noise Reduction Technologies for Future Commercial Subsonic Engines Area of Interest 1.0: Reliable and Affordable Control Systems

NASA Technical Reports Server (NTRS)

Myers, William; Winter, Steve

2006-01-01

The General Electric Reliable and Affordable Controls effort under the NASA Advanced Subsonic Technology (AST) Program has designed, fabricated, and tested advanced controls hardware and software to reduce emissions and improve engine safety and reliability. The original effort consisted of four elements: 1) a Hydraulic Multiplexer; 2) Active Combustor Control; 3) a Variable Displacement Vane Pump (VDVP); and 4) Intelligent Engine Control. The VDVP and Intelligent Engine Control elements were cancelled due to funding constraints and are reported here only to the state they progressed. The Hydraulic Multiplexing element developed and tested a prototype which improves reliability by combining the functionality of up to 16 solenoids and servo-valves into one component with a single electrically powered force motor. The Active Combustor Control element developed intelligent staging and control strategies for low emission combustors. This included development and tests of a Controlled Pressure Fuel Nozzle for fuel sequencing, a Fuel Multiplexer for individual fuel cup metering, and model-based control logic. Both the Hydraulic Multiplexer and Controlled Pressure Fuel Nozzle system were cleared for engine test. The Fuel Multiplexer was cleared for combustor rig test which must be followed by an engine test to achieve full maturation.

Control Surface Interaction Effects of the Active Aeroelastic Wing Wind Tunnel Model

NASA Technical Reports Server (NTRS)

Heeg, Jennifer

2006-01-01

This paper presents results from testing the Active Aeroelastic Wing wind tunnel model in NASA Langley s Transonic Dynamics Tunnel. The wind tunnel test provided an opportunity to study aeroelastic system behavior under combined control surface deflections, testing for control surface interaction effects. Control surface interactions were observed in both static control surface actuation testing and dynamic control surface oscillation testing. The primary method of evaluating interactions was examination of the goodness of the linear superposition assumptions. Responses produced by independently actuating single control surfaces were combined and compared with those produced by simultaneously actuating and oscillating multiple control surfaces. Adjustments to the data were required to isolate the control surface influences. Using dynamic data, the task increases, as both the amplitude and phase have to be considered in the data corrections. The goodness of static linear superposition was examined and analysis of variance was used to evaluate significant factors influencing that goodness. The dynamic data showed interaction effects in both the aerodynamic measurements and the structural measurements.

Detection of Acute and Long-Term Effects of Concussion: Dual-Task Gait Balance Control Versus Computerized Neurocognitive Test.

PubMed

Howell, David R; Osternig, Louis R; Chou, Li-Shan

2018-02-16

To examine the acute (within 72h of injury) and long-term (2mo postinjury) independent associations between objective dual-task gait balance and neurocognitive measurements among adolescents and young adults with a concussion and matched controls. Longitudinal case-control. Motion analysis laboratory. A total of 95 participants completed the study: 51 who sustained a concussion (mean age, 17.5±3.3y; 71% men) and 44 controls (mean age, 17.7±2.9y; 72% men). Participants who sustained a concussion underwent a dual-task gait analysis and computerized neurocognitive testing within 72 hours of injury and again 2 months later. Uninjured controls also completed the same test protocol in similar time increments. Not applicable. We compared dual-task gait balance control and computerized neurocognitive test performance between groups using independent samples t tests. Multivariable binary logistic regression models were then constructed for each testing time to determine the association between group membership (concussion vs control), dual-task gait balance control, and neurocognitive function. Medial-lateral center-of-mass displacement during dual-task gait was independently associated with group membership at the initial test (adjusted odds ratio [aOR], 2.432; 95% confidence interval [CI], 1.269-4.661) and 2-month follow-up test (aOR, 1.817; 95% CI, 1.014-3.256) tests. Visual memory composite scores were significantly associated with group membership at the initial hour postinjury time point (aOR, .953; 95% CI, .833-.998). However, the combination of computerized neurocognitive test variables did not predict dual-task gait balance control for participants with concussion, and no single neurocognitive variable was associated with dual-task gait balance control at either testing time. Dual-task assessments concurrently evaluating gait and cognitive performance may allow for the detection of persistent deficits beyond those detected by computerized neurocognitive deficits alone. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Simulation test beds for the space station electrical power system

NASA Technical Reports Server (NTRS)

Sadler, Gerald G.

1988-01-01

NASA Lewis Research Center and its prime contractor are responsible for developing the electrical power system on the space station. The power system will be controlled by a network of distributed processors. Control software will be verified, validated, and tested in hardware and software test beds. Current plans for the software test bed involve using real time and nonreal time simulations of the power system. This paper will discuss the general simulation objectives and configurations, control architecture, interfaces between simulator and controls, types of tests, and facility configurations.

A Manual Control Test for the Detection and Deterrence of Impaired Drivers

NASA Technical Reports Server (NTRS)

Stein, A. C.; Allen, R. W.; Jex, H. R.

1984-01-01

A brief manual control test and a decision strategy were developed, laboratory tested, and field validated which provide a means for detecting human operator impairment from alcohol or other drugs. The test requires the operator to stabilize progressively unstable controlled element dynamics. Control theory and experimental data verify that the human operator's control ability on this task is constrained by basic cybernetic characteristics, and that task performance is reliably affected by impairment effects on these characteristics. Assessment of human operator control ability is determined by a statistically based decision strategy. The operator is allowed several chances to exceed a preset pass criterion. Procedures are described for setting the pass criterion based on individual ability and a desired unimpaired failure rate. These procedures were field tested with apparatus installed in automobiles that were designed to discourage drunk drivers from operating their vehicles. This test program demonstrated that the control task and detection strategy could be applied in a practical setting to screen human operators for impairment in their basic cybernetic skills.

10 CFR 72.164 - Control of measuring and test equipment.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., instruments, and other measuring and testing devices used in activities affecting quality are properly... WASTE Quality Assurance § 72.164 Control of measuring and test equipment. The licensee, applicant for a... 10 Energy 2 2010-01-01 2010-01-01 false Control of measuring and test equipment. 72.164 Section 72...

40 CFR 1051.345 - What production-line testing records must I send to EPA?

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Testing Production-Line Vehicles and Engines § 1051.345 What production-line testing records must I send to EPA? (a.... We have not changed production processes or quality-control procedures for test engines (or vehicles...

40 CFR 1051.345 - What production-line testing records must I send to EPA?

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Testing Production-Line Vehicles and Engines § 1051.345 What production-line testing records must I send to EPA? (a.... We have not changed production processes or quality-control procedures for test engines (or vehicles...

40 CFR 1051.345 - What production-line testing records must I send to EPA?

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Testing Production-Line Vehicles and Engines § 1051.345 What production-line testing records must I send to EPA? (a.... We have not changed production processes or quality-control procedures for test engines (or vehicles...

40 CFR 1051.345 - What production-line testing records must I send to EPA?

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Testing Production-Line Vehicles and Engines § 1051.345 What production-line testing records must I send to EPA? (a.... We have not changed production processes or quality-control procedures for test engines (or vehicles...

40 CFR 1051.345 - What production-line testing records must I send to EPA?

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Testing Production-Line Vehicles and Engines § 1051.345 What production-line testing records must I send to EPA? (a.... We have not changed production processes or quality-control procedures for test engines (or vehicles...

Controlling Item Exposure Conditional on Ability in Computerized Adaptive Testing.

ERIC Educational Resources Information Center

Stocking, Martha L.; Lewis, Charles

1998-01-01

Ensuring item and pool security in a continuous testing environment is explored through a new method of controlling exposure rate of items conditional on ability level in computerized testing. Properties of this conditional control on exposure rate, when used in conjunction with a particular adaptive testing algorithm, are explored using simulated…

LPT. Low power test control building (TAN641) interior. Camera facing ...

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

LPT. Low power test control building (TAN-641) interior. Camera facing northeast at what remains of control room console. Cut in wall at right of view shows west wall of northern test cell. INEEL negative no. HD-40-4-4 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Advanced Control Design for Wind Turbines; Part I: Control Design, Implementation, and Initial Tests

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

Wright, A. D.; Fingersh, L. J.

The purpose of this report is to give wind turbine engineers information and examples of the design, testing through simulation, field implementation, and field testing of advanced wind turbine controls.

An automated testing tool for traffic signal controller functionalities.

DOT National Transportation Integrated Search

2010-03-01

The purpose of this project was to develop an automated tool that facilitates testing of traffic controller functionality using controller interface device (CID) technology. Benefits of such automated testers to traffic engineers include reduced test...

Inter-laboratory trial of a standardized sediment contact test with the aquatic plant Myriophyllum aquaticum (ISO 16191).

PubMed

Feiler, Ute; Ratte, Monika; Arts, Gertie; Bazin, Christine; Brauer, Frank; Casado, Carmen; Dören, Laszlo; Eklund, Britta; Gilberg, Daniel; Grote, Matthias; Gonsior, Guido; Hafner, Christoph; Kopf, Willi; Lemnitzer, Bernd; Liedtke, Anja; Matthias, Uwe; Okos, Ewa; Pandard, Pascal; Scheerbaum, Dirk; Schmitt-Jansen, Mechthild; Stewart, Kathleen; Teodorovic, Ivana; Wenzel, Andrea; Pluta, Hans-Jürgen

2014-03-01

A whole-sediment toxicity test with Myriophyllum aquaticum has been developed by the German Federal Institute of Hydrology and standardized within the International Organization for Standardization (ISO; ISO 16191). An international ring-test was performed to evaluate the precision of the test method. Four sediments (artificial, natural) were tested. Test duration was 10 d, and test endpoint was inhibition of growth rate (r) based on fresh weight data. Eighteen of 21 laboratories met the validity criterion of r ≥ 0.09 d(-1) in the control. Results from 4 tests that did not conform to test-performance criteria were excluded from statistical evaluation. The inter-laboratory variability of growth rates (20.6%-25.0%) and inhibition (26.6%-39.9%) was comparable with the variability of other standardized bioassays. The mean test-internal variability of the controls was low (7% [control], 9.7% [solvent control]), yielding a high discriminatory power of the given test design (median minimum detectable differences [MDD] 13% to 15%). To ensure these MDDs, an additional validity criterion of CV ≤ 15% of the growth rate in the controls was recommended. As a positive control, 90 mg 3,5-dichlorophenol/kg sediment dry mass was tested. The range of the expected growth inhibition was proposed to be 35 ± 15%. The ring test results demonstrated the reliability of the ISO 16191 toxicity test and its suitability as a tool to assess the toxicity of sediment and dredged material. © 2013 SETAC.

Survey of the prevalence and methodology of quality assurance for B-mode ultrasound image quality among veterinary sonographers.

PubMed

Hoscheit, Larry P; Heng, Hock Gan; Lim, Chee Kin; Weng, Hsin-Yi

2018-05-01

Image quality in B-mode ultrasound is important as it reflects the diagnostic accuracy and diagnostic information provided during clinical scanning. Quality assurance programs for B-mode ultrasound systems/components are comprised of initial quality acceptance testing and subsequent regularly scheduled quality control testing. The importance of quality assurance programs for B-mode ultrasound image quality using ultrasound phantoms is well documented in the human medical and medical physics literature. The purpose of this prospective, cross-sectional, survey study was to determine the prevalence and methodology of quality acceptance testing and quality control testing of image quality for ultrasound system/components among veterinary sonographers. An online electronic survey was sent to 1497 members of veterinary imaging organizations: the American College of Veterinary Radiology, the Veterinary Ultrasound Society, and the European Association of Veterinary Diagnostic Imaging, and a total of 167 responses were received. The results showed that the percentages of veterinary sonographers performing quality acceptance testing and quality control testing are 42% (64/151; 95% confidence interval 34-52%) and 26% (40/156: 95% confidence interval 19-33%) respectively. Of the respondents who claimed to have quality acceptance testing or quality control testing of image quality in place for their ultrasound system/components, 0% have performed quality acceptance testing or quality control testing correctly (quality acceptance testing 95% confidence interval: 0-6%, quality control testing 95% confidence interval: 0-11%). Further education and guidelines are recommended for veterinary sonographers in the area of quality acceptance testing and quality control testing for B-mode ultrasound equipment/components. © 2018 American College of Veterinary Radiology.

46 CFR 160.115-15 - Production inspections, tests, quality control, and conformance of winches.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 6 2013-10-01 2013-10-01 false Production inspections, tests, quality control, and... Launching Appliances-Winches § 160.115-15 Production inspections, tests, quality control, and conformance of... necessary to maintain quality control and to monitor compliance with the requirements of this subpart. (b...

46 CFR 160.115-15 - Production inspections, tests, quality control, and conformance of winches.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Production inspections, tests, quality control, and... Launching Appliances-Winches § 160.115-15 Production inspections, tests, quality control, and conformance of... necessary to maintain quality control and to monitor compliance with the requirements of this subpart. (b...

46 CFR 160.132-15 - Production inspections, tests, quality control, and conformance of davits.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 6 2013-10-01 2013-10-01 false Production inspections, tests, quality control, and... Launching Appliances-Davits § 160.132-15 Production inspections, tests, quality control, and conformance of... necessary to maintain quality control and to monitor compliance with the requirements of this subpart. (b...

46 CFR 160.115-15 - Production inspections, tests, quality control, and conformance of winches.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 6 2012-10-01 2012-10-01 false Production inspections, tests, quality control, and... Launching Appliances-Winches § 160.115-15 Production inspections, tests, quality control, and conformance of... necessary to maintain quality control and to monitor compliance with the requirements of this subpart. (b...

46 CFR 160.132-15 - Production inspections, tests, quality control, and conformance of davits.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Production inspections, tests, quality control, and... Launching Appliances-Davits § 160.132-15 Production inspections, tests, quality control, and conformance of... necessary to maintain quality control and to monitor compliance with the requirements of this subpart. (b...

46 CFR 160.132-15 - Production inspections, tests, quality control, and conformance of davits.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 6 2012-10-01 2012-10-01 false Production inspections, tests, quality control, and... Launching Appliances-Davits § 160.132-15 Production inspections, tests, quality control, and conformance of... necessary to maintain quality control and to monitor compliance with the requirements of this subpart. (b...

21 CFR 640.56 - Quality control test for potency.

Code of Federal Regulations, 2010 CFR

2010-04-01

... quality control test for potency may be performed by a clinical laboratory which meets the standards of... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Quality control test for potency. 640.56 Section...) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Cryoprecipitate § 640.56 Quality control...

Comparison of Relaxation as Self-control and Systematic Desensitization in the Treatment of Test Anxiety

ERIC Educational Resources Information Center

Snyder, Arden L.; Deffenbacher, Jerry L.

1977-01-01

Relaxation as self-control and desensitization were compared to a wait-list control in reduction of rest and other anxieties. Active treatments differed significantly from the control treatment. Subjects in both treatments reported less debilitating test anxiety, whereas desensitization subjects showed greater facilitating test anxiety. (Author)

Comparison of three control methods for an autonomous vehicle

NASA Astrophysics Data System (ADS)

Deshpande, Anup; Mathur, Kovid; Hall, Ernest

2010-01-01

The desirability and challenge of developing a completely autonomous vehicle and the rising need for more efficient use of energy by automobiles motivate this research- a study for an optimum solution to computer control of energy efficient vehicles. The purpose of this paper is to compare three control methods - mechanical, hydraulic and electric that have been used to convert an experimental all terrain vehicle to drive by wire which would eventually act as a test bed for conducting research on various technologies for autonomous operation. Computer control of basic operations in a vehicle namely steering, braking and speed control have been implemented and will be described in this paper. The output from a 3 axis motion controller is used for this purpose. The motion controller is interfaced with a software program using WSDK (Windows Servo Design Kit) as an intermediate tuning layer for tuning and parameter settings in autonomous operation. The software program is developed in C++. The voltage signal sent to the motion controller can be varied through the control program for desired results in controlling the steering motor, activating the hydraulic brakes and varying the vehicle's speed. The vehicle has been tested for its basic functionality which includes testing of street legal operations and also a 1000 mile test while running in a hybrid mode. The vehicle has also been tested for control when it is interfaced with devices such as a keyboard, joystick and sensors under full autonomous operation. The vehicle is currently being tested in various safety studies and is being used as a test bed for experiments in control courses and research studies. The significance of this research is in providing a greater understanding of conventional driving controls and the possibility of improving automobile safety by removing human error in control of a motor vehicle.

International Space Station Alpha trace contaminant control subassembly life test report

NASA Technical Reports Server (NTRS)

Tatara, J. D.; Perry, J. L.

1995-01-01

The Environmental Control and Life Support System (ECLSS) Life Test Program (ELTP) began with Trace Contaminant Control Subassembly (TCCS) Life Testing on November 9, 1992, at 0745. The purpose of the test, as stated in the NASA document 'Requirements for Trace Contaminant Control Subassembly High Temperature Catalytic Oxidizer Life Testing (Revision A)' was to 'provide for the long duration operation of the ECLSS TCCS HTCO (High Temperature Catalytic Oxidizer) at normal operating conditions... (and thus)... to determine the useful life of ECLSS hardware for use on long duration manned space missions.' Specifically, the test was designed to demonstrate thermal stability of the HTCO catalyst. The report details TCCS stability throughout the test. Graphs are included to aid in evaluating trends and subsystem anomalies. The report summarizes activities through the final day of testing, January 17, 1995 (test day 762).

Computer assisted thermal-vacuum testing

NASA Technical Reports Server (NTRS)

Petrie, W.; Mikk, G.

1977-01-01

In testing complex systems and components under dynamic thermal-vacuum environments, it is desirable to optimize the environment control sequence in order to reduce test duration and cost. This paper describes an approach where a computer is utilized as part of the test control operation. Real time test data is made available to the computer through time-sharing terminals at appropriate time intervals. A mathematical model of the test article and environmental control equipment is then operated on using the real time data to yield current thermal status, temperature analysis, trend prediction and recommended thermal control setting changes to arrive at the required thermal condition. The data acquisition interface and the time-sharing hook-up to an IBM-370 computer is described along with a typical control program and data demonstrating its use.

Experiment K-6-16. Morphological examination of rat testes. The effect of Cosmos 1887 flight on spermatogonial population and testosterone level in rat testes

NASA Technical Reports Server (NTRS)

Philpott, D. E.; Kato, K.; Stevenson, J.; Vasques, M.; Sapp, W.; Williams, C.; Popova, I. A.; Serova, L. V.

1990-01-01

Testes from rats flown on Cosmos 1887 for twelve and a half days were compared to basal control, synchronous control and vivarium maintained rats. When the mean weights of flight testes, normalized for weight/100 gms, were compared to the vivarium controls they were 6.7 percent lighter. Although the flight testes were lighter than the synchronous, the difference is not significant. Counts of spermatogonial cells from 5 animals in each group revealed a 4 percent decrease in flight compared to vivarium controls. In both cases the t-Test significance was less than 0.02. The serum testosterone levels of all animals (flight, synchronous and vivarium) were significantly below the basal controls.

Development of new selection tests for air traffic controllers.

DOT National Transportation Integrated Search

1977-12-01

This report describes the development of a new Multiplex Controller Aptitude Test for initial screening of FAA Air Traffic Controller applicants. Its content includes the traditional types of aptitude test items used for today's screening. In additio...

Economic consequences of paratuberculosis control in dairy cattle: A stochastic modeling study.

PubMed

Smith, R L; Al-Mamun, M A; Gröhn, Y T

2017-03-01

The cost of paratuberculosis to dairy herds, through decreased milk production, early culling, and poor reproductive performance, has been well-studied. The benefit of control programs, however, has been debated. A recent stochastic compartmental model for paratuberculosis transmission in US dairy herds was modified to predict herd net present value (NPV) over 25 years in herds of 100 and 1000 dairy cattle with endemic paratuberculosis at initial prevalence of 10% and 20%. Control programs were designed by combining 5 tests (none, fecal culture, ELISA, PCR, or calf testing), 3 test-related culling strategies (all test-positive, high-positive, or repeated positive), 2 test frequencies (annual and biannual), 3 hygiene levels (standard, moderate, or improved), and 2 cessation decisions (testing ceased after 5 negative whole-herd tests or testing continued). Stochastic dominance was determined for each herd scenario; no control program was fully dominant for maximizing herd NPV in any scenario. Use of the ELISA test was generally preferred in all scenarios, but no paratuberculosis control was highly preferred for the small herd with 10% initial prevalence and was frequently preferred in other herd scenarios. Based on their effect on paratuberculosis alone, hygiene improvements were not found to be as cost-effective as test-and-cull strategies in most circumstances. Global sensitivity analysis found that economic parameters, such as the price of milk, had more influence on NPV than control program-related parameters. We conclude that paratuberculosis control can be cost effective, and multiple control programs can be applied for equivalent economic results. Copyright © 2017 Elsevier B.V. All rights reserved.

Lumbopelvic motor control and low back pain in elite soccer players: a cross-sectional study.

PubMed

Grosdent, Stéphanie; Demoulin, Christophe; Rodriguez de La Cruz, Carlos; Giop, Romain; Tomasella, Marco; Crielaard, Jean-Michel; Vanderthommen, Marc

2016-01-01

This study aimed to investigate the relationship between the history of low back pain and quality of lumbopelvic motor control in soccer players. Forty-three male elite soccer players (mean age, 18.2 ± 1.4 years) filled in questionnaires related to low back pain and attended a session to assess lumbopelvic motor control by means of five tests (the bent knee fall out test, the knee lift abdominal test, the sitting knee extension test, the waiter's bow and the transversus abdominis test). A physiotherapist, blinded to the medical history of the participants, scored (0 = failed, 1 = correct) the performance of the players for each of the tests resulting in a lumbopelvic motor control score ranging from 0 to 5. Forty-seven per cent of the soccer players reported a disabling low back pain episode lasting at least two consecutive days in the previous year. These players scored worse lumbopelvic motor control than players without a history of low back pain (lumbopelvic motor control score of 1.8 vs. 3.3, P < 0.01). The between-groups difference was particularly marked for the bent knee fall out test, the knee lift abdominal test and the transversus abdominis test (P < 0.01). In conclusion, most soccer players with a history of low back pain had an altered lumbopelvic motor control. Further research should examine whether lumbopelvic motor control is etiologically involved in low back pain episodes in soccer players.

Quadrocopter Control Design and Flight Operation

NASA Technical Reports Server (NTRS)

Karwoski, Katherine

2011-01-01

A limiting factor in control system design and analysis for spacecraft is the inability to physically test new algorithms quickly and cheaply. Test flights of space vehicles are costly and take much preparation. As such, EV41 recently acquired a small research quadrocopter that has the ability to be a test bed for new control systems. This project focused on learning how to operate, fly, and maintain the quadrocopter, as well as developing and testing protocols for its use. In parallel to this effort, developing a model in Simulink facilitated the design and analysis of simple control systems for the quadrocopter. Software provided by the manufacturer enabled testing of the Simulink control system on the vehicle.

Adaptation of a modern medium helicopter (Sikorsky S-76) to higher harmonic control

NASA Technical Reports Server (NTRS)

Oleary, J. J.; Kottapalli, S. B. R.; Davis, M. W.

1985-01-01

Sikorsky Aircraft has performed analytical studies, design analyses, and risk reduction tests have been performed for Higher Harmonic Control (HHC) on the S-76. The S-76 is an 8 to 10,000 lb helicopter which cruises at 145 kts. Flight test hardware has been assembled, main servo frequency response tested and upgraded, aircraft control system shake tested and verified, open loop controllers designed and fabricated, closed loop controllers defined and evaluated, and rotors turning ground and flight tests planned for the near future. Open loop analysis shows that about 2 deg of higher harmonic feathering at the blade 75% radius will be required to eliminate 4P vibration in the cockpit.

Stepping-Motion Motor-Control Subsystem For Testing Bearings

NASA Technical Reports Server (NTRS)

Powers, Charles E.

1992-01-01

Control subsystem closed-loop angular-position-control system causing motor and bearing under test to undergo any of variety of continuous or stepping motions. Also used to test bearing-and-motor assemblies, motors, angular-position sensors including rotating shafts, and like. Monitoring subsystem gathers data used to evaluate performance of bearing or other article under test. Monitoring subsystem described in article, "Monitoring Subsystem For Testing Bearings" (GSC-13432).

Cognitive performance and psychosocial functioning in patients with bipolar disorder, unaffected siblings, and healthy controls.

PubMed

Vasconcelos-Moreno, Mirela P; Bücker, Joana; Bürke, Kelen P; Czepielewski, Leticia; Santos, Barbara T; Fijtman, Adam; Passos, Ives C; Kunz, Mauricio; Bonnín, Caterina Del Mar; Vieta, Eduard; Kapczinski, Flavio; Rosa, Adriane R; Kauer-Sant'Anna, Marcia

2016-01-01

To assess cognitive performance and psychosocial functioning in patients with bipolar disorder (BD), in unaffected siblings, and in healthy controls. Subjects were patients with BD (n=36), unaffected siblings (n=35), and healthy controls (n=44). Psychosocial functioning was accessed using the Functioning Assessment Short Test (FAST). A sub-group of patients with BD (n=21), unaffected siblings (n=14), and healthy controls (n=22) also underwent a battery of neuropsychological tests: California Verbal Learning Test (CVLT), Stroop Color and Word Test, and Wisconsin Card Sorting Test (WCST). Clinical and sociodemographic characteristics were analyzed using one-way analysis of variance or the chi-square test; multivariate analysis of covariance was used to examine differences in neuropsychological variables. Patients with BD showed higher FAST total scores (23.90±11.35) than healthy controls (5.86±5.47; p < 0.001) and siblings (12.60±11.83; p 0.001). Siblings and healthy controls also showed statistically significant differences in FAST total scores (p = 0.008). Patients performed worse than healthy controls on all CVLT sub-tests (p < 0.030) and in the number of correctly completed categories on WCST (p = 0.030). Siblings did not differ from healthy controls in cognitive tests. Unaffected siblings of patients with BD may show poorer functional performance compared to healthy controls. FAST scores may contribute to the development of markers of vulnerability and endophenotypic traits in at-risk populations.

Wastewater Characterization Survey Victor Valley, Wastewater Reclamation Authority and Hazardous Waste Survey at George AFB, Californi

DTIC Science & Technology

1987-01-01

however, the surfactant used iiffilqueous Film Forming FoanQfe apparently not, ^Recommendations: (1) AFFF ^should never be discharged to the sewer...210 2100 Test: 561 20-25 degrees C Control: 350 Test: 183 Control: 225 Test: 3550 Control: 1840 Test: 26.9 Control: 21.4 Days...Film Forming Foam ( AFFF ) was spilled on the pavement outside the Fire Department. According to standard practice, the spilled AFFF was contained

Development of a Work Control System for Propulsion Testing at Stennis Space Center (SSC)

NASA Technical Reports Server (NTRS)

Messer, Elizabeth A.

2004-01-01

In 1996, Stennis Space Center was given management authority for all Propulsion Testing for NASA. Over the next few years several research and development (R&D) test facilities were completed and brought up to full operation in what is known as the E-Complex Test Facility at Stennis Space Center. This paper will explain the requirements and steps taken to develop the current Test Operations' electronic work control system. The Work Control System developed includes work authorization documents such as test preparation sheets, discrepancy reports, pre-test briefing reports, and test requests.

Flight Test Approach to Adaptive Control Research

NASA Technical Reports Server (NTRS)

Pavlock, Kate Maureen; Less, James L.; Larson, David Nils

2011-01-01

The National Aeronautics and Space Administration s Dryden Flight Research Center completed flight testing of adaptive controls research on a full-scale F-18 testbed. The validation of adaptive controls has the potential to enhance safety in the presence of adverse conditions such as structural damage or control surface failures. This paper describes the research interface architecture, risk mitigations, flight test approach and lessons learned of adaptive controls research.

Aircraft flight test trajectory control

NASA Technical Reports Server (NTRS)

Menon, P. K. A.; Walker, R. A.

1988-01-01

Two control law design techniques are compared and the performance of the resulting controllers evaluated. The design requirement is for a flight test trajectory controller (FTTC) capable of closed-loop, outer-loop control of an F-15 aircraft performing high-quality research flight test maneuvers. The maneuver modeling, linearization, and design methodologies utilized in this research, are detailed. The results of applying these FTTCs to a nonlinear F-15 simulation are presented.

Step 1: Human System Integration Simulation and Flight Test Progress Report

NASA Technical Reports Server (NTRS)

2005-01-01

The Access 5 Human Systems Integration Work Package produced simulation and flight demonstration planning products for use throughout the program. These included: Test Objectives for Command, Control, Communications; Pilot Questionnaire for Command, Control, Communications; Air Traffic Controller Questionnaire for Command, Control, Communications; Test Objectives for Collision Avoidance; Pilot Questionnaire for Collision Avoidance; Plans for Unmanned Aircraft Systems Control Station Simulations Flight Requirements for the Airspace Operations Demonstration

Advanced Photovoltaic Inverter Control Development and Validation in a Controller-Hardware-in-the-Loop Test Bed

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

Prabakar, Kumaraguru; Shirazi, Mariko; Singh, Akanksha

Penetration levels of solar photovoltaic (PV) generation on the electric grid have increased in recent years. In the past, most PV installations have not included grid-support functionalities. But today, standards such as the upcoming revisions to IEEE 1547 recommend grid support and anti-islanding functions-including volt-var, frequency-watt, volt-watt, frequency/voltage ride-through, and other inverter functions. These functions allow for the standardized interconnection of distributed energy resources into the grid. This paper develops and tests low-level inverter current control and high-level grid support functions. The controller was developed to integrate advanced inverter functions in a systematic approach, thus avoiding conflict among the differentmore » control objectives. The algorithms were then programmed on an off-the-shelf, embedded controller with a dual-core computer processing unit and field-programmable gate array (FPGA). This programmed controller was tested using a controller-hardware-in-the-loop (CHIL) test bed setup using an FPGA-based real-time simulator. The CHIL was run at a time step of 500 ns to accommodate the 20-kHz switching frequency of the developed controller. The details of the advanced control function and CHIL test bed provided here will aide future researchers when designing, implementing, and testing advanced functions of PV inverters.« less

46 CFR 160.135-15 - Production inspections, tests, quality control, and conformance of lifeboats.

Code of Federal Regulations, 2013 CFR

2013-10-01

... materials are as per the plans approved under § 160.135-13(h) of this subpart. (2) Post assembly tests and... 46 Shipping 6 2013-10-01 2013-10-01 false Production inspections, tests, quality control, and... Lifeboats (SOLAS) § 160.135-15 Production inspections, tests, quality control, and conformance of lifeboats...

46 CFR 160.135-15 - Production inspections, tests, quality control, and conformance of lifeboats.

Code of Federal Regulations, 2012 CFR

2012-10-01

... materials are as per the plans approved under § 160.135-13(h) of this subpart. (2) Post assembly tests and... 46 Shipping 6 2012-10-01 2012-10-01 false Production inspections, tests, quality control, and... Lifeboats (SOLAS) § 160.135-15 Production inspections, tests, quality control, and conformance of lifeboats...

A magnetic bearing control approach using flux feedback

NASA Technical Reports Server (NTRS)

Groom, Nelson J.

1989-01-01

A magnetic bearing control approach using flux feedback is described and test results for a laboratory model magnetic bearing actuator are presented. Test results were obtained using a magnetic bearing test fixture, which is also described. The magnetic bearing actuator consists of elements similar to those used in a laboratory test model Annular Momentum Control Device (AMCD).

40 CFR 1048.345 - What production-line testing records must I send to EPA?

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD SPARK-IGNITION ENGINES Testing Production-line Engines § 1048.345 What production-line testing records must I send to EPA? (a... procedures for test engines in a way that might affect emission controls. All the information in this report...

40 CFR 1048.345 - What production-line testing records must I send to EPA?

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD SPARK-IGNITION ENGINES Testing Production-line Engines § 1048.345 What production-line testing records must I send to EPA? (a... procedures for test engines in a way that might affect emission controls. All the information in this report...

40 CFR 1048.345 - What production-line testing records must I send to EPA?

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD SPARK-IGNITION ENGINES Testing Production-line Engines § 1048.345 What production-line testing records must I send to EPA? (a... procedures for test engines in a way that might affect emission controls. All the information in this report...

40 CFR 1048.345 - What production-line testing records must I send to EPA?

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD SPARK-IGNITION ENGINES Testing Production-line Engines § 1048.345 What production-line testing records must I send to EPA? (a... procedures for test engines in a way that might affect emission controls. All the information in this report...

40 CFR 1048.345 - What production-line testing records must I send to EPA?

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD SPARK-IGNITION ENGINES Testing Production-line Engines § 1048.345 What production-line testing records must I send to EPA? (a... procedures for test engines in a way that might affect emission controls. All the information in this report...

NASA Tests 2nd RS-25 Flight Engine for Space Launch System

NASA Image and Video Library

2018-01-16

On Jan. 16, 2018, engineers at NASA’s Stennis Space Center in Mississippi conducted a certification test of another RS-25 engine flight controller on the A-1 Test Stand at Stennis Space Center. The 365-second, full-duration test came a month after the space agency capped a year of RS-25 testing with a flight controller test in mid-December. For the “green run” test the flight controller was installed on RS-25 developmental engine E0528 and fired just as during an actual launch. Once certified, the flight controller will be removed and installed on a flight engine for use by NASA’s new deep-space rocket, the Space Launch System (SLS).

Strategies for Controlling Item Exposure in Computerized Adaptive Testing with the Generalized Partial Credit Model

ERIC Educational Resources Information Center

Davis, Laurie Laughlin

2004-01-01

Choosing a strategy for controlling item exposure has become an integral part of test development for computerized adaptive testing (CAT). This study investigated the performance of six procedures for controlling item exposure in a series of simulated CATs under the generalized partial credit model. In addition to a no-exposure control baseline…

30 CFR 28.33 - Quality control test methods, equipment, and records; review by MSHA; revocation of approval.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Quality control test methods, equipment, and... USE WITH DIRECT CURRENT IN PROVIDING SHORT-CIRCUIT PROTECTION FOR TRAILING CABLES IN COAL MINES Quality Control § 28.33 Quality control test methods, equipment, and records; review by MSHA; revocation...

30 CFR 28.33 - Quality control test methods, equipment, and records; review by MSHA; revocation of approval.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Quality control test methods, equipment, and... USE WITH DIRECT CURRENT IN PROVIDING SHORT-CIRCUIT PROTECTION FOR TRAILING CABLES IN COAL MINES Quality Control § 28.33 Quality control test methods, equipment, and records; review by MSHA; revocation...

30 CFR 28.33 - Quality control test methods, equipment, and records; review by MSHA; revocation of approval.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Quality control test methods, equipment, and... USE WITH DIRECT CURRENT IN PROVIDING SHORT-CIRCUIT PROTECTION FOR TRAILING CABLES IN COAL MINES Quality Control § 28.33 Quality control test methods, equipment, and records; review by MSHA; revocation...

30 CFR 28.33 - Quality control test methods, equipment, and records; review by MSHA; revocation of approval.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Quality control test methods, equipment, and... USE WITH DIRECT CURRENT IN PROVIDING SHORT-CIRCUIT PROTECTION FOR TRAILING CABLES IN COAL MINES Quality Control § 28.33 Quality control test methods, equipment, and records; review by MSHA; revocation...

30 CFR 28.33 - Quality control test methods, equipment, and records; review by MSHA; revocation of approval.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Quality control test methods, equipment, and... USE WITH DIRECT CURRENT IN PROVIDING SHORT-CIRCUIT PROTECTION FOR TRAILING CABLES IN COAL MINES Quality Control § 28.33 Quality control test methods, equipment, and records; review by MSHA; revocation...

Compact Analyzer/Controller For Oxygen-Enrichment System

NASA Technical Reports Server (NTRS)

Puster, Richard L.; Singh, Jag J.; Sprinkle, Danny R.

1990-01-01

System controls hypersonic air-breathing engine tests. Compact analyzer/controller developed, built, and tested in small-scale wind tunnel prototype of the 8' HTT (High-Temperature Tunnel). Monitors level of oxygen and controls addition of liquid oxygen to enrich atmosphere for combustion. Ensures meaningful ground tests of hypersonic engines in range of speeds from mach 4 to mach 7.

Advanced Ground Systems Maintenance Cryogenics Test Lab Control System Upgrade Project

NASA Technical Reports Server (NTRS)

Harp, Janice Leshay

2014-01-01

This project will outfit the Simulated Propellant Loading System (SPLS) at KSC's Cryogenics Test Laboratory with a new programmable logic control system. The control system upgrade enables the Advanced Ground Systems Maintenace Element Integration Team and other users of the SPLS to conduct testing in a controls environment similar to that used at the launch pad.

21 CFR 226.58 - Laboratory controls.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Laboratory controls. Laboratory controls shall include the establishment of adequate specifications and test... establishment of master records containing appropriate specifications and a description of the test procedures... necessary laboratory test procedures to check such specifications. (c) Assays which shall be made of...

Design and Testing of Flight Control Laws on the RASCAL Research Helicopter

NASA Technical Reports Server (NTRS)

Frost, Chad R.; Hindson, William S.; Moralez. Ernesto, III; Tucker, George E.; Dryfoos, James B.

2001-01-01

Two unique sets of flight control laws were designed, tested and flown on the Army/NASA Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) JUH-60A Black Hawk helicopter. The first set of control laws used a simple rate feedback scheme, intended to facilitate the first flight and subsequent flight qualification of the RASCAL research flight control system. The second set of control laws comprised a more sophisticated model-following architecture. Both sets of flight control laws were developed and tested extensively using desktop-to-flight modeling, analysis, and simulation tools. Flight test data matched the model predicted responses well, providing both evidence and confidence that future flight control development for RASCAL will be efficient and accurate.

Active vibration control for flexible rotor by optimal direct-output feedback control

NASA Technical Reports Server (NTRS)

Nonami, Kenzou; Dirusso, Eliseo; Fleming, David P.

1989-01-01

Experimental research tests were performed to actively control the rotor vibrations of a flexible rotor mounted on flexible bearing supports. The active control method used in the tests is called optimal direct-output feedback control. This method uses four electrodynamic actuators to apply control forces directly to the bearing housings in order to achieve effective vibration control of the rotor. The force actuators are controlled by an analog controller that accepts rotor displacement as input. The controller is programmed with experimentally determined feedback coefficients; the output is a control signal to the force actuators. The tests showed that this active control method reduced the rotor resonance peaks due to unbalance from approximately 250 micrometers down to approximately 25 micrometers (essentially runout level). The tests were conducted over a speed range from 0 to 10,000 rpm; the rotor system had nine critical speeds within this speed range. The method was effective in significantly reducing the rotor vibration for all of the vibration modes and critical speeds.

Active vibration control for flexible rotor by optimal direct-output feedback control

NASA Technical Reports Server (NTRS)

Nonami, K.; Dirusso, E.; Fleming, D. P.

1989-01-01

Experimental research tests were performed to actively control the rotor vibrations of a flexible rotor mounted on flexible bearing supports. The active control method used in the tests is called optimal direct-output feedback control. This method uses four electrodynamic actuators to apply control forces directly to the bearing housings in order to achieve effective vibration control of the rotor. The force actuators are controlled by an analog controller that accepts rotor displacement as input. The controller is programmed with experimentally determined feedback coefficients; the output is a control signal to the force actuators. The tests showed that this active control method reduced the rotor resonance peaks due to unbalance from approximately 250 microns down to approximately 25 microns (essentially runout level). The tests were conducted over a speed range from 0 to 10,000 rpm; the rotor system had nine critical speeds within this speed range. The method was effective in significantly reducing the rotor vibration for all of the vibration modes and critical speeds.

CR-Calculus and adaptive array theory applied to MIMO random vibration control tests

NASA Astrophysics Data System (ADS)

Musella, U.; Manzato, S.; Peeters, B.; Guillaume, P.

2016-09-01

Performing Multiple-Input Multiple-Output (MIMO) tests to reproduce the vibration environment in a user-defined number of control points of a unit under test is necessary in applications where a realistic environment replication has to be achieved. MIMO tests require vibration control strategies to calculate the required drive signal vector that gives an acceptable replication of the target. This target is a (complex) vector with magnitude and phase information at the control points for MIMO Sine Control tests while in MIMO Random Control tests, in the most general case, the target is a complete spectral density matrix. The idea behind this work is to tailor a MIMO random vibration control approach that can be generalized to other MIMO tests, e.g. MIMO Sine and MIMO Time Waveform Replication. In this work the approach is to use gradient-based procedures over the complex space, applying the so called CR-Calculus and the adaptive array theory. With this approach it is possible to better control the process performances allowing the step-by-step Jacobian Matrix update. The theoretical bases behind the work are followed by an application of the developed method to a two-exciter two-axis system and by performance comparisons with standard methods.

Ground test for vibration control demonstrator

NASA Astrophysics Data System (ADS)

Meyer, C.; Prodigue, J.; Broux, G.; Cantinaud, O.; Poussot-Vassal, C.

2016-09-01

In the objective of maximizing comfort in Falcon jets, Dassault Aviation is developing an innovative vibration control technology. Vibrations of the structure are measured at several locations and sent to a dedicated high performance vibration control computer. Control laws are implemented in this computer to analyse the vibrations in real time, and then elaborate orders sent to the existing control surfaces to counteract vibrations. After detailing the technology principles, this paper focuses on the vibration control ground demonstration that was performed by Dassault Aviation in May 2015 on Falcon 7X business jet. The goal of this test was to attenuate vibrations resulting from fixed forced excitation delivered by shakers. The ground test demonstrated the capability to implement an efficient closed-loop vibration control with a significant vibration level reduction and validated the vibration control law design methodology. This successful ground test was a prerequisite before the flight test demonstration that is now being prepared. This study has been partly supported by the JTI CleanSky SFWA-ITD.

An optimal controller for an electric ventricular-assist device: theory, implementation, and testing.

PubMed

Klute, G K; Tasch, U; Geselowitz, D B

1992-04-01

This paper addresses the development and testing of an optimal position feedback controller for the Penn State electric ventricular-assist device (EVAD). The control law is designed to minimize the expected value of the EVAD's power consumption for a targeted patient population. The closed-loop control law is implemented on an Intel 8096 microprocessor and in vitro test runs show that this controller improves the EVAD's efficiency by 15-21%, when compared with the performance of the currently used feedforward control scheme.

F100 multivariable control synthesis program: Evaluation of a multivariable control using a real-time engine simulation

NASA Technical Reports Server (NTRS)

Szuch, J. R.; Soeder, J. F.; Seldner, K.; Cwynar, D. S.

1977-01-01

The design, evaluation, and testing of a practical, multivariable, linear quadratic regulator control for the F100 turbofan engine were accomplished. NASA evaluation of the multivariable control logic and implementation are covered. The evaluation utilized a real time, hybrid computer simulation of the engine. Results of the evaluation are presented, and recommendations concerning future engine testing of the control are made. Results indicated that the engine testing of the control should be conducted as planned.

Flight control system design factors for applying automated testing techniques

NASA Technical Reports Server (NTRS)

Sitz, Joel R.; Vernon, Todd H.

1990-01-01

Automated validation of flight-critical embedded systems is being done at ARC Dryden Flight Research Facility. The automated testing techniques are being used to perform closed-loop validation of man-rated flight control systems. The principal design features and operational experiences of the X-29 forward-swept-wing aircraft and F-18 High Alpha Research Vehicle (HARV) automated test systems are discussed. Operationally applying automated testing techniques has accentuated flight control system features that either help or hinder the application of these techniques. The paper also discusses flight control system features which foster the use of automated testing techniques.

Closed-Loop Acoustic Control of Reverberant Room for Satellite Environmental Testing

NASA Astrophysics Data System (ADS)

Janssens, Karl; Bianciardi, Fabio; Sabbatini, Danilo; Debille, Jan; Carrella, Alex

2012-07-01

The full satellite acoustic test is an important milestone in a satellite launch survivability verification campaign. This test is required to verify the satellite’s mechanical design against the high-level acoustic loads induced by the launch vehicle during the atmospheric flight. During the test, the satellite is subjected to a broadband diffuse acoustic field, reproducing the pressure levels observed during launch. The excitation is in most cases provided by a combination of horns for the low frequencies and noise generators for the higher frequencies. Acoustic control tests are commonly performed in reverberant rooms, controlling the sound pressure levels in third octave bands over the specified target spectrum. This paper discusses an automatic feedback control system for acoustic control of large reverberation rooms for satellite environmental testing. The acoustic control system consists of parallel third octave PI (Proportional Integral) feedback controllers that take the reverberation characteristics of the room into consideration. The drive output of the control system is shaped at every control step based on the comparison of the average third octave noise spectrum, measured from a number of microphones in the test room, with the target spectrum. Cross-over filters split the output drive into band- limited signals to feed each of the horns. The control system is realized in several steps. In the first phase, a dynamic process model is developed, including the non-linear characteristics of the horns and the reverberant properties of the room. The model is identified from dynamic experiments using system identification techniques. In the next phase, an adequate control strategy is designed which is capable of reaching the target spectrum in the required time period without overshoots. This control strategy is obtained from model-in-the-loop (MIL) simulations, evaluating the performance of various potential strategies. Finally, the proposed strategy is implemented in real-time and its control performance tested and validated.

Non-inferiority tests for anti-infective drugs using control group quantiles.

PubMed

Fay, Michael P; Follmann, Dean A

2016-12-01

In testing for non-inferiority of anti-infective drugs, the primary endpoint is often the difference in the proportion of failures between the test and control group at a landmark time. The landmark time is chosen to approximately correspond to the qth historic quantile of the control group, and the non-inferiority margin is selected to be reasonable for the target level q. For designing these studies, a troubling issue is that the landmark time must be pre-specified, but there is no guarantee that the proportion of control failures at the landmark time will be close to the target level q. If the landmark time is far from the target control quantile, then the pre-specified non-inferiority margin may not longer be reasonable. Exact variable margin tests have been developed by Röhmel and Kieser to address this problem, but these tests can have poor power if the observed control failure rate at the landmark time is far from its historic value. We develop a new variable margin non-inferiority test where we continue sampling until a pre-specified proportion of failures, q, have occurred in the control group, where q is the target quantile level. The test does not require any assumptions on the failure time distributions, and hence, no knowledge of the true [Formula: see text] control quantile for the study is needed. Our new test is exact and has power comparable to (or greater than) its competitors when the true control quantile from the study equals (or differs moderately from) its historic value. Our nivm R package performs the test and gives confidence intervals on the difference in failure rates at the true target control quantile. The tests can be applied to time to cure or other numeric variables as well. A substantial proportion of new anti-infective drugs being developed use non-inferiority tests in their development, and typically, a pre-specified landmark time and its associated difference margin are set at the design stage to match a specific target control quantile. If through changing standard of care or selection of a different population the target quantile for the control group changes from its historic value, then the appropriateness of the pre-specified margin at the landmark time may be questionable. Our proposed test avoids this problem by sampling until a pre-specified proportion of the controls have failed. © The Author(s) 2016.

Accuracy of four commonly used color vision tests in the identification of cone disorders.

PubMed

Thiadens, Alberta A H J; Hoyng, Carel B; Polling, Jan Roelof; Bernaerts-Biskop, Riet; van den Born, L Ingeborgh; Klaver, Caroline C W

2013-04-01

To determine which color vision test is most appropriate for the identification of cone disorders. In a clinic-based study, four commonly used color vision tests were compared between patients with cone dystrophy (n = 37), controls with normal visual acuity (n = 35), and controls with low vision (n = 39) and legal blindness (n = 11). Mean outcome measures were specificity, sensitivity, positive predictive value and discriminative accuracy of the Ishihara test, Hardy-Rand-Rittler (HRR) test, and the Lanthony and Farnsworth Panel D-15 tests. In the comparison between cone dystrophy and all controls, sensitivity, specificity and predictive value were highest for the HRR and Ishihara tests. When patients were compared to controls with normal vision, discriminative accuracy was highest for the HRR test (c-statistic for PD-axes 1, for T-axis 0.851). When compared to controls with poor vision, discriminative accuracy was again highest for the HRR test (c-statistic for PD-axes 0.900, for T-axis 0.766), followed by the Lanthony Panel D-15 test (c-statistic for PD-axes 0.880, for T-axis 0.500) and Ishihara test (c-statistic 0.886). Discriminative accuracies of all tests did not further decrease when patients were compared to controls who were legally blind. The HRR, Lanthony Panel D-15 and Ishihara all have a high discriminative accuracy to identify cone disorders, but the highest scores were for the HRR test. Poor visual acuity slightly decreased the accuracy of all tests. Our advice is to use the HRR test since this test also allows for evaluation of all three color axes and quantification of color defects.

The Effectiveness of Educational Interventions to Enhance the Adoption of Fee-Based Arsenic Testing in Bangladesh: A Cluster Randomized Controlled Trial

PubMed Central

George, Christine Marie; Inauen, Jennifer; Rahman, Sheikh Masudur; Zheng, Yan

2013-01-01

Arsenic (As) testing could help 22 million people, using drinking water sources that exceed the Bangladesh As standard, to identify safe sources. A cluster randomized controlled trial was conducted to evaluate the effectiveness of household education and local media in the increasing demand for fee-based As testing. Randomly selected households (N = 452) were divided into three interventions implemented by community workers: 1) fee-based As testing with household education (HE); 2) fee-based As testing with household education and a local media campaign (HELM); and 3) fee-based As testing alone (Control). The fee for the As test was US$ 0.28, higher than the cost of the test (US$ 0.16). Of households with untested wells, 93% in both intervention groups HE and HELM purchased an As test, whereas only 53% in the control group. In conclusion, fee-based As testing with household education is effective in the increasing demand for As testing in rural Bangladesh. PMID:23716409

The effectiveness of educational interventions to enhance the adoption of fee-based arsenic testing in Bangladesh: a cluster randomized controlled trial.

PubMed

George, Christine Marie; Inauen, Jennifer; Rahman, Sheikh Masudur; Zheng, Yan

2013-07-01

Arsenic (As) testing could help 22 million people, using drinking water sources that exceed the Bangladesh As standard, to identify safe sources. A cluster randomized controlled trial was conducted to evaluate the effectiveness of household education and local media in the increasing demand for fee-based As testing. Randomly selected households (N = 452) were divided into three interventions implemented by community workers: 1) fee-based As testing with household education (HE); 2) fee-based As testing with household education and a local media campaign (HELM); and 3) fee-based As testing alone (Control). The fee for the As test was US$ 0.28, higher than the cost of the test (US$ 0.16). Of households with untested wells, 93% in both intervention groups HE and HELM purchased an As test, whereas only 53% in the control group. In conclusion, fee-based As testing with household education is effective in the increasing demand for As testing in rural Bangladesh.

Engineering Development Tests Airdrop Controlled Exit System (ACES)

DTIC Science & Technology

1980-09-01

AIRDROP CONTROLLED EXIT SYSTEM ( ACES ) RECOVERY PARACHUTES TELEMETERING DATA 20. D5TFAC c• Cat •u•u am revers e• ift n•ceesafy ad Ide•lityf by block...rTECHNICAL REPORT , NATICK /TR-82 /017 f C’n Engineering Development Tests Airdropý Controlled Exit System ( ACES ) COPY CLV40ble to DTIC doe’ io C...and,50.,,,10) s. TYPE OF REPORT A PERIOn COVEnEo Test Report ENCINEERTNG DEVELOPMENT TESTS Oct 79 - Apr 80 AIRDROP CONTROLLED EXIT SYSTEM ( ACES ) 6

A comparative overview of modal testing and system identification for control of structures

NASA Technical Reports Server (NTRS)

Juang, J.-N.; Pappa, R. S.

1988-01-01

A comparative overview is presented of the disciplines of modal testing used in structural engineering and system identification used in control theory. A list of representative references from both areas is given, and the basic methods are described briefly. Recent progress on the interaction of modal testing and control disciplines is discussed. It is concluded that combined efforts of researchers in both disciplines are required for unification of modal testing and system identification methods for control of flexible structures.

Effectiveness of the U.S. National HIV Testing Day Campaigns in Promoting HIV Testing: Evidence from CDC-Funded HIV Testing Sites, 2010

PubMed Central

Mulatu, Mesfin S.

2014-01-01

Objectives We assessed if HIV testing and diagnoses increased during the week of National HIV Testing Day (NHTD) and if characteristics of people who were tested varied compared with control weeks. Methods We analyzed HIV testing data from the 2010 National HIV Prevention Program Monitoring and Evaluation system to compare NHTD week (June 24–30, 2010) with two control weeks (January 7–13, 2010, and August 12–18, 2010) for the number of HIV testing events and new HIV-positive diagnoses, by demographics and other HIV-related variables. Characteristics associated with testing during NHTD week compared with control weeks were identified using Chi-square analyses. Results In 2010, an average of 15,000 more testing events were conducted and 100 more new HIV-positive diagnoses were identified during NHTD week than during the control weeks (p<0.001). Compared with control weeks, people tested during NHTD week were significantly less likely to be aged 20–29 years and non-Hispanic white and significantly more likely to be (1) aged ≥50 years, (2) non-Hispanic black or African American, (3) men who have sex with men, (4) low-risk heterosexuals, (5) tested with a rapid HIV test, or (6) tested in a non-health-care setting. Conclusion In 2010, CDC-funded HIV testing events and new HIV-positive diagnoses increased during NHTD week compared with control weeks. HIV testing programs increased the use of rapid tests and returned a high percentage of test results. NHTD campaigns reached populations disproportionately affected by HIV and further expanded testing to people traditionally less likely to be tested. Incorporating strategies used during NHTD in programs conducted throughout the year may assist in increasing HIV testing and the number of HIV-positive diagnoses. PMID:25177056

[The establishment and application of internal quality control system for real-time quantitative PCR detection of BCR-ABL (P210) transcript levels].

PubMed

Zhong, C Q; He, N; Hua, M Q; Wei, X D; Ma, D X; Ji, C Y

2016-09-14

Objective: To set internal quality control system of BCR-ABL (P210) transcript levels for real-time quantitative PCR (RQ-PCR). Methods: Using K562 cells and HL-60 cells, we prepared high- and low-level BCR-ABL internal quality control substance. The BCR-ABL (P210) transcript levels of internal quality control substance have been determined for 184 times together with clinical samples from August 2013 to October 2015. The slope rate, intercept and correlation coefficient of standard curve were calculated according to different reagent lots (lots number 20130303, 20131212, 20140411 and 20150327 are called R1、R2、R3 and R4 for short respectively), and the detection results of quality control substance were calculated according to different reagent lots and quality control substance lots (lots number 20130725, 20140611 are called Q1、Q2 for short respectively). Then the results were analyzed by Levey-Jennings quality control chart combined with Westgard multi-rules theory. Results: ①We analyzed the slope rate and intercept of standard curve. Fifty-three times of the R1 reagent detection, 80 times of the R3 reagent detection and 14 times of the R4 reagent detection were all under control. For 37 times detection of R2 reagent, the slope rate was out of control for 6 times. It was lower than x - s for the 2-8 tests and upper the average for the 12-37 tests. The intercept was out of control for 9 times, upper the x + s for the 1-8 tests and lower the average for the 12-37 tests. ② According to the detection results of quality control substance, for Q1 quality control substance, 49 tests by R1 reagent were under control, and 1 out of 23 tests by R2 reagent was out of control. For Q2 quality control substance, 14 tests by R2 reagent detection, 72 tests by R3 reagent detection and 14 tests by R4 reagent were all under control. Conclusion: The preparation of high- and low-level quality control substance using K562 and HL-60 cells was convenient and the detection results were reliable and stable. The application of quality control substance combined with slope rate and intercept in the internal quality control may contribute to quality assurance for quantitative detection of BCR-ABL (P210) transcript levels.

Control structural interaction testbed: A model for multiple flexible body verification

NASA Technical Reports Server (NTRS)

Chory, M. A.; Cohen, A. L.; Manning, R. A.; Narigon, M. L.; Spector, V. A.

1993-01-01

Conventional end-to-end ground tests for verification of control system performance become increasingly complicated with the development of large, multiple flexible body spacecraft structures. The expense of accurately reproducing the on-orbit dynamic environment and the attendant difficulties in reducing and accounting for ground test effects limits the value of these tests. TRW has developed a building block approach whereby a combination of analysis, simulation, and test has replaced end-to-end performance verification by ground test. Tests are performed at the component, subsystem, and system level on engineering testbeds. These tests are aimed at authenticating models to be used in end-to-end performance verification simulations: component and subassembly engineering tests and analyses establish models and critical parameters, unit level engineering and acceptance tests refine models, and subsystem level tests confirm the models' overall behavior. The Precision Control of Agile Spacecraft (PCAS) project has developed a control structural interaction testbed with a multibody flexible structure to investigate new methods of precision control. This testbed is a model for TRW's approach to verifying control system performance. This approach has several advantages: (1) no allocation for test measurement errors is required, increasing flight hardware design allocations; (2) the approach permits greater latitude in investigating off-nominal conditions and parametric sensitivities; and (3) the simulation approach is cost effective, because the investment is in understanding the root behavior of the flight hardware and not in the ground test equipment and environment.

Reactor transient control in support of PFR/TREAT TUCOP experiments

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

Burrows, D.R.; Larsen, G.R.; Harrison, L.J.

1984-01-01

Unique energy deposition and experiment control requirements posed bythe PFR/TREAT series of transient undercooling/overpower (TUCOP) experiments resulted in equally unique TREAT reactor operations. New reactor control computer algorithms were written and used with the TREAT reactor control computer system to perform such functions as early power burst generation (based on test train flow conditions), burst generation produced by a step insertion of reactivity following a controlled power ramp, and shutdown (SCRAM) initiators based on both test train conditions and energy deposition. Specialized hardware was constructed to simulate test train inputs to the control computer system so that computer algorithms couldmore » be tested in real time without irradiating the experiment.« less

46 CFR 160.156-15 - Production inspections, tests, quality control, and conformance of rescue boats and fast rescue...

Code of Federal Regulations, 2012 CFR

2012-10-01

... materials are as per the plans approved under § 160.156-13(h) of this subpart. (2) Post assembly tests and... 46 Shipping 6 2012-10-01 2012-10-01 false Production inspections, tests, quality control, and... inspections, tests, quality control, and conformance of rescue boats and fast rescue boats. (a) Unless the...

46 CFR 160.156-15 - Production inspections, tests, quality control, and conformance of rescue boats and fast rescue...

Code of Federal Regulations, 2013 CFR

2013-10-01

... materials are as per the plans approved under § 160.156-13(h) of this subpart. (2) Post assembly tests and... 46 Shipping 6 2013-10-01 2013-10-01 false Production inspections, tests, quality control, and... inspections, tests, quality control, and conformance of rescue boats and fast rescue boats. (a) Unless the...

Many tests of significance: new methods for controlling type I errors.

PubMed

Keselman, H J; Miller, Charles W; Holland, Burt

2011-12-01

There have been many discussions of how Type I errors should be controlled when many hypotheses are tested (e.g., all possible comparisons of means, correlations, proportions, the coefficients in hierarchical models, etc.). By and large, researchers have adopted familywise (FWER) control, though this practice certainly is not universal. Familywise control is intended to deal with the multiplicity issue of computing many tests of significance, yet such control is conservative--that is, less powerful--compared to per test/hypothesis control. The purpose of our article is to introduce the readership, particularly those readers familiar with issues related to controlling Type I errors when many tests of significance are computed, to newer methods that provide protection from the effects of multiple testing, yet are more powerful than familywise controlling methods. Specifically, we introduce a number of procedures that control the k-FWER. These methods--say, 2-FWER instead of 1-FWER (i.e., FWER)--are equivalent to specifying that the probability of 2 or more false rejections is controlled at .05, whereas FWER controls the probability of any (i.e., 1 or more) false rejections at .05. 2-FWER implicitly tolerates 1 false rejection and makes no explicit attempt to control the probability of its occurrence, unlike FWER, which tolerates no false rejections at all. More generally, k-FWER tolerates k - 1 false rejections, but controls the probability of k or more false rejections at α =.05. We demonstrate with two published data sets how more hypotheses can be rejected with k-FWER methods compared to FWER control.

Initial Flight Test of the Production Support Flight Control Computers at NASA Dryden Flight Research Center

NASA Technical Reports Server (NTRS)

Carter, John; Stephenson, Mark

1999-01-01

The NASA Dryden Flight Research Center has completed the initial flight test of a modified set of F/A-18 flight control computers that gives the aircraft a research control law capability. The production support flight control computers (PSFCC) provide an increased capability for flight research in the control law, handling qualities, and flight systems areas. The PSFCC feature a research flight control processor that is "piggybacked" onto the baseline F/A-18 flight control system. This research processor allows for pilot selection of research control law operation in flight. To validate flight operation, a replication of a standard F/A-18 control law was programmed into the research processor and flight-tested over a limited envelope. This paper provides a brief description of the system, summarizes the initial flight test of the PSFCC, and describes future experiments for the PSFCC.

Intertester and intratester reliability of a movement control test battery for patients with knee osteoarthritis and controls

PubMed Central

Kaukinen, P.T.; Arokoski, J.P.; Huber, E.O.; Luomajoki, H.A.

2017-01-01

Objectives: To develop a test battery of movement control (MC) tests and assess its intertester and intratester reliability. Methods: 29 subjects with knee OA with mean age of 64.7 (SD 8.7) years and 12 controls without either knee pain or previous diagnosis of OA (mean age 36.6 (SD 16.2) years) were included. Two experienced physiotherapists rated the filmed test performance of six MC tests blinded to the patients and to each other on 3-point scale as correct, incorrect or failed. Weighted kappa coefficient (wK) with 95% confidence interval (95%CI) and the percentage of agreement were calculated for each test. Results: One-leg stance, one-leg squat 30 degrees and step down tests showed moderate to excellent inter- and intratester reliability with wK ranging between 0.43-0.85 for intertester and 0.51-0.80 for intratester reliability. The reliability of the 90 degrees squat test, small squat and step up tests was poor (wK ranging between 0.09-0.50). Conclusions: One-leg stance test, one-leg squat 30 degrees and step down test are reliable in the subjects with knee OA and controls. Further studies are needed to evaluate the discriminative validity of the reliable tests. PMID:28860422

Preliminary supersonic flight test evaluation of performance seeking control

NASA Technical Reports Server (NTRS)

Orme, John S.; Gilyard, Glenn B.

1993-01-01

Digital flight and engine control, powerful onboard computers, and sophisticated controls techniques may improve aircraft performance by maximizing fuel efficiency, maximizing thrust, and extending engine life. An adaptive performance seeking control system for optimizing the quasi-steady state performance of an F-15 aircraft was developed and flight tested. This system has three optimization modes: minimum fuel, maximum thrust, and minimum fan turbine inlet temperature. Tests of the minimum fuel and fan turbine inlet temperature modes were performed at a constant thrust. Supersonic single-engine flight tests of the three modes were conducted using varied after burning power settings. At supersonic conditions, the performance seeking control law optimizes the integrated airframe, inlet, and engine. At subsonic conditions, only the engine is optimized. Supersonic flight tests showed improvements in thrust of 9 percent, increases in fuel savings of 8 percent, and reductions of up to 85 deg R in turbine temperatures for all three modes. The supersonic performance seeking control structure is described and preliminary results of supersonic performance seeking control tests are given. These findings have implications for improving performance of civilian and military aircraft.

High Stability Engine Control (HISTEC) Flight Test Results

NASA Technical Reports Server (NTRS)

Southwick, Robert D.; Gallops, George W.; Kerr, Laura J.; Kielb, Robert P.; Welsh, Mark G.; DeLaat, John C.; Orme, John S.

1998-01-01

The High Stability Engine Control (HISTEC) Program, managed and funded by the NASA Lewis Research Center, is a cooperative effort between NASA and Pratt & Whitney (P&W). The program objective is to develop and flight demonstrate an advanced high stability integrated engine control system that uses real-time, measurement-based estimation of inlet pressure distortion to enhance engine stability. Flight testing was performed using the NASA Advanced Controls Technologies for Integrated Vehicles (ACTIVE) F-15 aircraft at the NASA Dryden Flight Research Center. The flight test configuration, details of the research objectives, and the flight test matrix to achieve those objectives are presented. Flight test results are discussed that show the design approach can accurately estimate distortion and perform real-time control actions for engine accommodation.

40 CFR 63.4167 - How do I establish the emission capture system and add-on control device operating limits during...

Code of Federal Regulations, 2013 CFR

2013-07-01

... system and add-on control device operating limits during the performance test? 63.4167 Section 63.4167... Emission Rate with Add-on Controls Option § 63.4167 How do I establish the emission capture system and add-on control device operating limits during the performance test? During the performance test required...

A portable hardware-in-the-loop (HIL) device for automotive diagnostic control systems.

PubMed

Palladino, A; Fiengo, G; Lanzo, D

2012-01-01

In-vehicle driving tests for evaluating the performance and diagnostic functionalities of engine control systems are often time consuming, expensive, and not reproducible. Using a hardware-in-the-loop (HIL) simulation approach, new control strategies and diagnostic functions on a controller area network (CAN) line can be easily tested in real time, in order to reduce the effort and the cost of the testing phase. Nowadays, spark ignition engines are controlled by an electronic control unit (ECU) with a large number of embedded sensors and actuators. In order to meet the rising demand of lower emissions and fuel consumption, an increasing number of control functions are added into such a unit. This work aims at presenting a portable electronic environment system, suited for HIL simulations, in order to test the engine control software and the diagnostic functionality on a CAN line, respectively, through non-regression and diagnostic tests. The performances of the proposed electronic device, called a micro hardware-in-the-loop system, are presented through the testing of the engine management system software of a 1.6 l Fiat gasoline engine with variable valve actuation for the ECU development version. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

75 FR 66295 - Fixed Assets, Member Business Loans, and Regulatory Flexibility Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-28

... assets, member business loans (MBL), stress testing of investments, and discretionary control of...) discretionary control of investments; (6) stress testing of investments; (7) zero-coupon securities; (8... fixed assets, MBL, stress testing of investments, and discretionary control of investments provisions of...

How Is Cancer Risk Measured?

MedlinePlus

... more groups. The people in one group (the control group ) may be given a standard screening test (if one exists) or no screening test. The ... for the human papillomavirus (HPV) and those who test negative for HPV. The ... Case-control studies Case-control studies are like cohort studies ...

Thermal Expert System (TEXSYS): Systems automony demonstration project, volume 1. Overview

NASA Technical Reports Server (NTRS)

Glass, B. J. (Editor)

1992-01-01

The Systems Autonomy Demonstration Project (SADP) produced a knowledge-based real-time control system for control and fault detection, isolation, and recovery (FDIR) of a prototype two-phase Space Station Freedom external active thermal control system (EATCS). The Thermal Expert System (TEXSYS) was demonstrated in recent tests to be capable of reliable fault anticipation and detection, as well as ordinary control of the thermal bus. Performance requirements were addressed by adopting a hierarchical symbolic control approach-layering model-based expert system software on a conventional, numerical data acquisition and control system. The model-based reasoning capabilities of TEXSYS were shown to be advantageous over typical rule-based expert systems, particularly for detection of unforeseen faults and sensor failures. Volume 1 gives a project overview and testing highlights. Volume 2 provides detail on the EATCS test bed, test operations, and online test results. Appendix A is a test archive, while Appendix B is a compendium of design and user manuals for the TEXSYS software.

Actively controlled shaft seals for aerospace applications

NASA Astrophysics Data System (ADS)

Salant, Richard F.

The objective of years 4 and 5 of this project (1992 and 1993) is to determine experimentally the behavior and operating characteristics of a controllable mechanical seal, and to identify potential problem areas. A controllable mechanical seal is one in which the thickness of the lubricating film separating the sealing surfaces is adjustable, and can be controlled by an electronic control system, based on information supplied by sensors that monitor the condition of the film. This work builds upon work done during years 1-3, in which a controllable mechanical seal was designed, analyzed, and fabricated. At the beginning of year 4, the mechanical seal and test rig was assembled, and preliminary testing begun. The five major tasks of years 4 and 5 encompass instrumentation, configuration changes of the mechanical seal to optimize its performance, systematic steady state tests, systematic transient tests, and a final report. During this reporting period, significant progress was made on instrumenting the test rig and modifying the design to optimize the seal's performance. Initial steady state tests were also performed.

46 CFR 61.35-3 - Required tests and checks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... controls must control and cycle the unit in the proper manner and sequence. Proper prepurge, ignition...) Limit controls. Shutdown caused by the limit controls must be verified. (9) Water level controls. Water level controls must be tested by slowly lowering the water level in the boiler. Each operating water...

46 CFR 61.35-3 - Required tests and checks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... controls must control and cycle the unit in the proper manner and sequence. Proper prepurge, ignition...) Limit controls. Shutdown caused by the limit controls must be verified. (9) Water level controls. Water level controls must be tested by slowly lowering the water level in the boiler. Each operating water...

46 CFR 61.35-3 - Required tests and checks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... controls must control and cycle the unit in the proper manner and sequence. Proper prepurge, ignition...) Limit controls. Shutdown caused by the limit controls must be verified. (9) Water level controls. Water level controls must be tested by slowly lowering the water level in the boiler. Each operating water...

46 CFR 61.35-3 - Required tests and checks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... controls must control and cycle the unit in the proper manner and sequence. Proper prepurge, ignition...) Limit controls. Shutdown caused by the limit controls must be verified. (9) Water level controls. Water level controls must be tested by slowly lowering the water level in the boiler. Each operating water...

42 CFR 493.1425 - Standard; Testing personnel responsibilities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... laboratory's quality control policies, document all quality control activities, instrument and procedural... HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity Testing § 493.1425 Standard; Testing personnel...

Five different tests of reaction time evaluated in HIV seropositive men.

PubMed

Dunlop, O; Bjørklund, R A; Abdelnoor, M; Myrvang, B

1992-09-01

In an attempt to develop a short neuropsychological test battery five different tests of reaction time were assessed according to their ability to discriminate between HIV seropositive men and healthy controls. In all tests a patient group with clinical symptoms was slower than the control group. In the complex reaction time test, which has a large cognitive aspect, even a clinically "asymptomatic" group was slower than the control group. The movement test, a new test with a large motor component, identified most slow responders, defining approximately half of the patients with clinical symptoms and one third of the "asymptomatic" patients as such. A test battery consisting of three tests is suggested for serial assessment and screening.

The Design of Software for Three-Phase Induction Motor Test System

NASA Astrophysics Data System (ADS)

Haixiang, Xu; Fengqi, Wu; Jiai, Xue

2017-11-01

The design and development of control system software is important to three-phase induction motor test equipment, which needs to be completely familiar with the test process and the control procedure of test equipment. In this paper, the software is developed according to the national standard (GB/T1032-2005) about three-phase induction motor test method by VB language. The control system and data analysis software and the implement about motor test system are described individually, which has the advantages of high automation and high accuracy.

Implementation of an Adaptive Controller System from Concept to Flight Test

NASA Technical Reports Server (NTRS)

Larson, Richard R.; Burken, John J.; Butler, Bradley S.; Yokum, Steve

2009-01-01

The National Aeronautics and Space Administration Dryden Flight Research Center (Edwards, California) is conducting ongoing flight research using adaptive controller algorithms. A highly modified McDonnell-Douglas NF-15B airplane called the F-15 Intelligent Flight Control System (IFCS) is used to test and develop these algorithms. Modifications to this airplane include adding canards and changing the flight control systems to interface a single-string research controller processor for neural network algorithms. Research goals include demonstration of revolutionary control approaches that can efficiently optimize aircraft performance in both normal and failure conditions and advancement of neural-network-based flight control technology for new aerospace system designs. This report presents an overview of the processes utilized to develop adaptive controller algorithms during a flight-test program, including a description of initial adaptive controller concepts and a discussion of modeling formulation and performance testing. Design finalization led to integration with the system interfaces, verification of the software, validation of the hardware to the requirements, design of failure detection, development of safety limiters to minimize the effect of erroneous neural network commands, and creation of flight test control room displays to maximize human situational awareness; these are also discussed.

Impact of providing fee data on laboratory test ordering: a controlled clinical trial.

PubMed

Feldman, Leonard S; Shihab, Hasan M; Thiemann, David; Yeh, Hsin-Chieh; Ardolino, Margaret; Mandell, Steven; Brotman, Daniel J

2013-05-27

Inpatient care providers often order laboratory tests without any appreciation for the costs of the tests. To determine whether we could decrease the number of laboratory tests ordered by presenting providers with test fees at the time of order entry in a tertiary care hospital, without adding extra steps to the ordering process. Controlled clinical trial. Tertiary care hospital. All providers, including physicians and nonphysicians, who ordered laboratory tests through the computerized provider order entry system at The Johns Hopkins Hospital. We randomly assigned 61 diagnostic laboratory tests to an "active" arm (fee displayed) or to a control arm (fee not displayed). During a 6-month baseline period (November 10, 2008, through May 9, 2009), we did not display any fee data. During a 6-month intervention period 1 year later (November 10, 2009, through May 9, 2010), we displayed fees, based on the Medicare allowable fee, for active tests only. We examined changes in the total number of orders placed, the frequency of ordered tests (per patient-day), and total charges associated with the orders according to the time period (baseline vs intervention period) and by study group (active test vs control). For the active arm tests, rates of test ordering were reduced from 3.72 tests per patient-day in the baseline period to 3.40 tests per patient-day in the intervention period (8.59% decrease; 95% CI, -8.99% to -8.19%). For control arm tests, ordering increased from 1.15 to 1.22 tests per patient-day from the baseline period to the intervention period (5.64% increase; 95% CI, 4.90% to 6.39%) (P < .001 for difference over time between active and control tests). Presenting fee data to providers at the time of order entry resulted in a modest decrease in test ordering. Adoption of this intervention may reduce the number of inappropriately ordered diagnostic tests.

ENHANCING TEST SENSITIVITY IN TOXICITY TESTING BY USING A STATISTICAL PERFORMANCE STANDARD

EPA Science Inventory

Previous reports have shown that within-test sensitivity can vary markedly among laboratories. Experts have advocated an empirical approach to controlling test variability based on the MSD, control means, and other test acceptability criteria. (The MSD represents the smallest dif...

Controls in new construction reactors-factory testing of the non-safety portion of the Lungmen nuclear power plant distributed control system

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

Wu, Y. S.; Dick, J. W.; Tetirick, C. W.

2006-07-01

The construction permit for Taipower's Lungmen Nuclear Units 1 and 2, two ABWR plants, was issued on March 17, 1999[1], The construction of these units is progressing actively at site. The digital I and C system supplied by GE, which is designated as the Distributed Control and Information System (DCIS) in this project, is being implemented primarily at one vendor facility. In order to ensure the reliability, safety and availability of the DCIS, it is required to comprehensively test the whole DCIS in factory. This article describes the test requirements and acceptance criteria for functional testing of the Non-Safety Distributedmore » Control and Information system (DCIS) for Taiwan Power's Lungmen Units 1 and 2 GE selected Invensys as the equipment supplier for this Non-Safety portion of DCIS. The DCIS system of the Lungmen Units is a physically distributed control system. Field transmitters are connected to hard I/O terminal inputs on the Invensys I/A system. Once the signal is digitized on FBMs (Field Bus Modules) in Remote Multiplexing Units (RMUs), the signal is passed into an integrated control software environment. Control is based on the concept of compounds and blocks where each compound is a logical collection of blocks that performs a control function. Each point identified by control compound and block can be individually used throughout the DCIS system by referencing its unique name. In the Lungmen Project control logic and HSI (Human System Interface) requirements are divided into individual process systems called MPLs (Master Parts List). Higher-level Plant Computer System (PCS) algorithms access control compounds and blocks in these MPLs to develop functions. The test requirements and acceptance criteria for the DCIS system of the Lungmen Project are divided into three general categories (see 1,2,3 below) of verification, which in turn are divided into several specific tests: 1. DCIS System Physical Checks a) RMU Test - To confirm that the hard I/O database is installed on the DCIS and is physically addressed correctly. Test process is injecting a signal at each DCIS hard I/O terminal boundary and verifying correct receipt on the DCIS. b) DCIS Network Stress Test - Confirms system viability under extreme high load conditions beyond the plant could ever experience. Load conditions include alarm showers on the DCIS system to emulate plant upsets. c) System Hardware Configuration Test - These are typical checks of the DCIS system hardware including fault reporting, redundancy, and normal computer functions. d) Performance Test - Test confirms high level hardware and system capability attributes such as control system time response, 'cold start' reboots, and processor loading e) Electromagnetic compatibility tests - To verify the electromagnetic viability of the system and individual components 2. Implementation of Plant Systems and Systems Integration a) MPL Logic Tests -To confirm control functions implemented to system logic performs as expected, and that parameters are passed correctly between system control schemes. b) Data Link (Gateway) Tests- To verify third party interfaces to the DCIS. c) Plant Computer System (PCS) Logic Tests- Tests to verify that higher-level PCS logic is correctly implemented, performs as expected, and parameters are passed correctly between PCS sub-systems and MPL systems. Included the PCS sub-systems, Safety Parameter Display System, Historian, Alarms, Maintenance monitoring etc. 3. Unique Third Party Interfacing and Integration into the DCIS The set of controls for Automatic Power Regulation, Feedwater, and Recirculation Flow are specific in that these systems are implemented on third party Triple Modular Redundant (TMR) hardware, which was connected to the DCIS and are tested via full simulation. The TMR system is supplied by GE Control Solutions on the Mark Vie platform. (authors)« less

Test and control computer user's guide for a digital beam former test system

NASA Technical Reports Server (NTRS)

Alexovich, Robert E.; Mallasch, Paul G.

1992-01-01

A Digital Beam Former Test System was developed to determine the effects of noise, interferers and distortions, and digital implementations of beam forming as applied to the Tracking and Data Relay Satellite 2 (TDRS 2) architectures. The investigation of digital beam forming with application to TDRS 2 architectures, as described in TDRS 2 advanced concept design studies, was conducted by the NASA/Lewis Research Center for NASA/Goddard Space Flight Center. A Test and Control Computer (TCC) was used as the main controlling element of the digital Beam Former Test System. The Test and Control Computer User's Guide for a Digital Beam Former Test System provides an organized description of the Digital Beam Former Test System commands. It is written for users who wish to conduct tests of the Digital Beam forming Test processor using the TCC. The document describes the function, use, and syntax of the TCC commands available to the user while summarizing and demonstrating the use of the commands wtihin DOS batch files.

Viking 1975 Orbiter Development Test Model/Lander Dynamic Test Model dynamic environmental testing - An overview

NASA Technical Reports Server (NTRS)

Milder, G.

1975-01-01

The current work presents an overview of the Viking 1975 environmental testing from an engineering standpoint. An extremely large vibration test fixture had to be designed, analyzed, and integrated into a test setup that employed hydrostatic bearings in a new fashion. A vibration control system was also required that would allow for thirty-six channels of sine-wave peak select control from acceleration, force-of-strain transducers. In addition, some 68 channels of peak limiting shutdown capability were needed for backup and monitoring of other data during the forced vibration test. Pretesting included analyses of the fixture design, overturning moment, control system capabilities, and response of the entire spacecraft/fixture/exciter system to the test environment. Closed-loop control for acoustic testing was a necessity due to the fact that the Viking spacecraft took up a major portion of the volume of the 10,000 cu ft chamber. The spacecraft emerged from testing undamaged.

Remote telescope control of site testing with ASCOM

NASA Astrophysics Data System (ADS)

Ji, Kaifan; Liang, Bo; Peng, Yajie; Wang, Feng

2012-04-01

Remote telescope control is significant important for the astronomical site testing. Basing on ASCOM standard, a prototype of remote telescope control system has been implemented. In this paper, the details of the system design, both server end and client end, are introduced. We tested the prototype on a narrow-band dial-up networking and controlled a real remote telescope successfully. The result indicates that it is effective to control remote telescope and other devices with ASCOM.

Flight Investigation to Improve the Dynamic Longitudinal Stability and Control-Feel Characteristics of the P-63A-1 Airplane (AAF No. 42-68889) with Closely Balanced Experimental Elevators

NASA Technical Reports Server (NTRS)

Johnson, Harold I.

1946-01-01

Results of flight tests of a control-feel aid presented. This device consisted of a spring and dashpot connected in series between the control stick and airplane structure. The device was tested in combination with an experimental elevator and bobweight which had given unsatisfactory dynamic stability and control-feel characteristics in previous tests. The control-feel aid effected marked improvement in both the control-feel characteristics and the control-feel dynamic longitudinal stability of the airplane.

Aileron controls for wind turbine applications

NASA Technical Reports Server (NTRS)

Miller, D. R.; Putoff, R. L.

1984-01-01

Horizontal axis wind turbines which utilize partial or full variable blade pitch to regulate rotor speed were examined. The weight and costs of these systems indicated a need for alternate methods of rotor control. Aileron control is an alternative which has potential to meet this need. Aileron control rotors were tested on the Mod-O wind turbine to determine their power regulation and shutdown characteristics. Test results for a 20 and 38% chord aileron control rotor are presented. Test is shown that aileron control is a viable method for safety for safely controlling rotor speed, following a loss of general load.

Aileron controls for wind turbine applications

NASA Technical Reports Server (NTRS)

Miller, D. R.; Puthoff, R. L.

1984-01-01

Horizontal axis wind turbines which utilize partial or full variable blade pitch to regulate rotor speed were examined. The weight and costs of these systems indicated a need for alternate methods of rotor control. Aileron control is an alternative which has potential to meet this need. Aileron control rotors were tested on the Mod-O wind turbine to determine their power regulation and shutdown characteristics. Test results for a 20 and 38 percent chord aileron control rotor are presented. Test is shown that aileron control is a viable method for safety for safely controlling rotor speed, following a loss of general load.

49 CFR 236.587 - Departure test.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Inspection and Tests; Locomotive § 236.587 Departure test. (a) The automatic train stop, train control, or cab signal apparatus on each locomotive, except a locomotive or a...

40 CFR 799.9110 - TSCA acute oral toxicity.

Code of Federal Regulations, 2011 CFR

2011-07-01

... number. A system to assign animals to test groups and control groups randomly is required. (E) Housing... randomization in assigning animals to test and control groups. (3) Rationale for selection of species, if other... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

40 CFR 799.9110 - TSCA acute oral toxicity.

Code of Federal Regulations, 2013 CFR

2013-07-01

... number. A system to assign animals to test groups and control groups randomly is required. (E) Housing... randomization in assigning animals to test and control groups. (3) Rationale for selection of species, if other... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

40 CFR 799.9110 - TSCA acute oral toxicity.

Code of Federal Regulations, 2010 CFR

2010-07-01

... number. A system to assign animals to test groups and control groups randomly is required. (E) Housing... randomization in assigning animals to test and control groups. (3) Rationale for selection of species, if other... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

40 CFR 799.9110 - TSCA acute oral toxicity.

Code of Federal Regulations, 2014 CFR

2014-07-01

... number. A system to assign animals to test groups and control groups randomly is required. (E) Housing... randomization in assigning animals to test and control groups. (3) Rationale for selection of species, if other... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

40 CFR 799.9110 - TSCA acute oral toxicity.

Code of Federal Regulations, 2012 CFR

2012-07-01

... number. A system to assign animals to test groups and control groups randomly is required. (E) Housing... randomization in assigning animals to test and control groups. (3) Rationale for selection of species, if other... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

10 CFR 72.162 - Test control.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 2 2013-01-01 2013-01-01 false Test control. 72.162 Section 72.162 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL... Test control. The licensee, applicant for a license, certificate holder, and applicant for a CoC shall...

10 CFR 72.162 - Test control.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Test control. 72.162 Section 72.162 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL... Test control. The licensee, applicant for a license, certificate holder, and applicant for a CoC shall...

10 CFR 72.162 - Test control.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 2 2014-01-01 2014-01-01 false Test control. 72.162 Section 72.162 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL... Test control. The licensee, applicant for a license, certificate holder, and applicant for a CoC shall...

14 CFR 23.683 - Operation tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.683 Operation tests. (a) It must be shown by operation tests that, when the controls are... controls, loads not less than those corresponding to the maximum pilot effort established under § 23.405...

14 CFR 29.683 - Operation tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Control Systems § 29.683 Operation tests. It must be shown by operation tests that, when the controls are operated from the pilot compartment with the control system loaded to correspond with loads specified for the system, the system is free...

14 CFR 23.683 - Operation tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.683 Operation tests. (a) It must be shown by operation tests that, when the controls are... controls, loads not less than those corresponding to the maximum pilot effort established under § 23.405...

14 CFR 23.683 - Operation tests.

Code of Federal Regulations, 2014 CFR

2014-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.683 Operation tests. (a) It must be shown by operation tests that, when the controls are... controls, loads not less than those corresponding to the maximum pilot effort established under § 23.405...

14 CFR 23.683 - Operation tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.683 Operation tests. (a) It must be shown by operation tests that, when the controls are... controls, loads not less than those corresponding to the maximum pilot effort established under § 23.405...

14 CFR 27.683 - Operation tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Control Systems § 27.683 Operation tests. It must be shown by operation tests that, when the controls are operated from the pilot compartment with the control system loaded to correspond with loads specified for the system, the system is free from...

14 CFR 23.683 - Operation tests.

Code of Federal Regulations, 2012 CFR

2012-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.683 Operation tests. (a) It must be shown by operation tests that, when the controls are... controls, loads not less than those corresponding to the maximum pilot effort established under § 23.405...

10 CFR 71.125 - Control of measuring and test equipment.

Code of Federal Regulations, 2010 CFR

2010-01-01

... MATERIAL Quality Assurance § 71.125 Control of measuring and test equipment. The licensee, certificate holder, and applicant for a CoC shall establish measures to assure that tools, gauges, instruments, and other measuring and testing devices used in activities affecting quality are properly controlled...