Interpretation of the results of the CORA-33 dry core BWR test

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

Ott, L.J.; Hagen, S.

All BWR degraded core experiments performed prior to CORA-33 were conducted under ``wet`` core degradation conditions for which water remains within the core and continuous steaming feeds metal/steam oxidation reactions on the in-core metallic surfaces. However, one dominant set of accident scenarios would occur with reduced metal oxidation under ``dry`` core degradation conditions and, prior to CORA-33, this set had been neglected experimentally. The CORA-33 experiment was designed specifically to address this dominant set of BWR ``dry`` core severe accident scenarios and to partially resolve phenomenological uncertainties concerning the behavior of relocating metallic melts draining into the lower regions ofmore » a ``dry`` BWR core. CORA-33 was conducted on October 1, 1992, in the CORA tests facility at KfK. Review of the CORA-33 data indicates that the test objectives were achieved; that is, core degradation occurred at a core heatup rate and a test section axial temperature profile that are prototypic of full-core nuclear power plant (NPP) simulations at ``dry`` core conditions. Simulations of the CORA-33 test at ORNL have required modification of existing control blade/canister materials interaction models to include the eutectic melting of the stainless steel/Zircaloy interaction products and the heat of mixing of stainless steel and Zircaloy. The timing and location of canister failure and melt intrusion into the fuel assembly appear to be adequately simulated by the ORNL models. This paper will present the results of the posttest analyses carried out at ORNL based upon the experimental data and the posttest examination of the test bundle at KfK. The implications of these results with respect to degraded core modeling and the associated safety issues are also discussed.« less

Influence of ceramic dental crown coating substrate thickness ratio on strain energy release rate

NASA Astrophysics Data System (ADS)

Khasnulhadi, K.; Daud, R.; Mat, F.; Noor, S. N. F. M.; Basaruddin, K. S.; Sulaiman, M. H.

2017-10-01

This paper presents the analysis of coating substrate thickness ratio effect on the crown coating fracture behaviour. The bi-layer material is examined under four point bending with pre-crack at the bottom of the core material by using finite element. Three different coating thickness of core/substrate was tested which is 1:1, 1:2 and 2:1. The fracture parameters are analysed based on bilayer and homogenous elastic interaction. The result shows that the ratio thickness of core/veneer provided a significant effect on energy release rate.

Comparison of a newly developed automated and quantitative hepatitis C virus (HCV) core antigen test with the HCV RNA assay for clinical usefulness in confirming anti-HCV results.

PubMed

Kesli, Recep; Polat, Hakki; Terzi, Yuksel; Kurtoglu, Muhammet Guzel; Uyar, Yavuz

2011-12-01

Hepatitis C virus (HCV) is a global health care problem. Diagnosis of HCV infection is mainly based on the detection of anti-HCV antibodies as a screening test with serum samples. Recombinant immunoblot assays are used as supplemental tests and for the final detection and quantification of HCV RNA in confirmatory tests. In this study, we aimed to compare the HCV core antigen test with the HCV RNA assay for confirming anti-HCV results to determine whether the HCV core antigen test may be used as an alternative confirmatory test to the HCV RNA test and to assess the diagnostic values of the total HCV core antigen test by determining the diagnostic specificity and sensitivity rates compared with the HCV RNA test. Sera from a total of 212 treatment-naive patients were analyzed for anti-HCV and HCV core antigen both with the Abbott Architect test and with the molecular HCV RNA assay consisting of a reverse transcription-PCR method as a confirmatory test. The diagnostic sensitivity, specificity, and positive and negative predictive values of the HCV core antigen assay compared to the HCV RNA test were 96.3%, 100%, 100%, and 89.7%, respectively. The levels of HCV core antigen showed a good correlation with those from the HCV RNA quantification (r = 0.907). In conclusion, the Architect HCV antigen assay is highly specific, sensitive, reliable, easy to perform, reproducible, cost-effective, and applicable as a screening, supplemental, and preconfirmatory test for anti-HCV assays used in laboratory procedures for the diagnosis of hepatitis C virus infection.

Analysis of Monolith Cores from an Engineering Scale Demonstration of a Prospective Cast Stone Process

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

Crawford, C. L.; Cozzi, A. D.; Hill, K. A.

2016-06-01

The primary disposition path of Low Activity Waste (LAW) at the DOE Hanford Site is vitrification. A cementitious waste form is one of the alternatives being considered for the supplemental immobilization of the LAW that will not be treated by the primary vitrification facility. Washington River Protection Solutions (WRPS) has been directed to generate and collect data on cementitious or pozzolanic waste forms such as Cast Stone. This report documents the coring and leach testing of monolithic samples cored from an engineering-scale demonstration (ES Demo) with non-radioactive simulants. The ES Demo was performed at SRNL in October of 2013 usingmore » the Scaled Continuous Processing Facility (SCPF) to fill an 8.5 ft. diameter x 3.25 ft. high container with simulated Cast Stone grout. The Cast Stone formulation was chosen from the previous screening tests. Legacy salt solution from previous Hanford salt waste testing was adjusted to correspond to the average LAW composition generated from the Hanford Tank Waste Operation Simulator (HTWOS). The dry blend materials, ordinary portland cement (OPC), Class F fly ash, and ground granulated blast furnace slag (GGBFS or BFS), were obtained from Lafarge North America in Pasco, WA. In 2014 core samples originally obtained approximately six months after filling the ES Demo were tested along with bench scale molded samples that were collected during the original pour. A latter set of core samples were obtained in late March of 2015, eighteen months after completion of the original ES Demo. Core samples were obtained using a 2” diameter x 11” long coring bit. The ES Demo was sampled in three different regions consisting of an outer ring, a middle ring and an inner core zone. Cores from these three lateral zones were further segregated into upper, middle and lower vertical segments. Monolithic core samples were tested using the Environmental Protection Agency (EPA) Method 1315, which is designed to provide mass transfer rates (release rates) of inorganic analytes contained in monolithic material under diffusion controlled release conditions as a function of leaching time. Compressive strength measurements and drying tests were also performed on the 2015 samples. Leachability indices reported are based on analyte concentrations determined from dissolution of the dried samples.« less

Honeycomb Core Permeability Under Mechanical Loads

NASA Technical Reports Server (NTRS)

Glass, David E.; Raman, V. V.; Venkat, Venki S.; Sankaran, Sankara N.

1997-01-01

A method for characterizing the air permeability of sandwich core materials as a function of applied shear stress was developed. The core material for the test specimens was either Hexcel HRP-3/16-8.0 and or DuPont Korex-1/8-4.5 and was nominally one-half inch thick and six inches square. The facesheets where made of Hercules' AS4/8552 graphite/epoxy (Gr/Ep) composites and were nominally 0.059-in. thick. Cytec's Metalbond 1515-3M epoxy film adhesive was used for co-curing the facesheets to the core. The permeability of the specimens during both static (tension) and dynamic (reversed and non-reversed) shear loads were measured. The permeability was measured as the rate of air flow through the core from a circular 1-in2 area of the core exposed to an air pressure of 10.0 psig. In both the static and dynamic testing, the Korex core experienced sudden increases in core permeability corresponding to a core catastrophic failure, while the URP core experienced a gradual increase in the permeability prior to core failure. The Korex core failed at lower loads than the HRP core both in the transverse and ribbon directions.

COBRA-WC pretest predictions and post-test analysis of the FOTA temperature distribution during FFTF natural-circulation transients

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

Khan, E.U.; George, T.L.; Rector, D.R.

The natural circulation tests of the Fast Flux Test Facility (FFTF) demonstrated a safe and stable transition from forced convection to natural convection and showed that natural convection may adequately remove decay heat from the reactor core. The COBRA-WC computer code was developed by the Pacific Northwest laboratory (PNL) to account for buoyancy-induced coolant flow redistribution and interassembly heat transfer, effects that become important in mitigating temperature gradients and reducing reactor core temperatures when coolant flow rate in the core is low. This report presents work sponsored by the US Department of Energy (DOE) with the objective of checking themore » validity of COBRA-WC during the first 220 seconds (sec) of the FFTF natural-circulation (plant-startup) tests using recorded data from two instrumented Fuel Open Test Assemblies (FOTAs). Comparison of COBRA-WC predictions of the FOTA data is a part of the final confirmation of the COBRA-WC methodology for core natural-convection analysis.« less

The feasibility of recharge rate determinations using the steady- state centrifuge method

USGS Publications Warehouse

Nimmo, J.R.; Stonestrom, David A.; Akstin, K.C.

1994-01-01

The establishment of steady unsaturated flow in a centrifuge permits accurate measurement of small values of hydraulic conductivity (K). This method can provide a recharge determination if it is applied to an unsaturated core sample from a depth at which gravity alone drives the flow. A K value determined at the in situ water content indicates the long-term average recharge rate at a point. Tests of this approach have been made at two sites. For sandy core samples a better knowledge of the matric pressure profiles is required before a recharge rate can be determined. Fine-textured cores required new developments of apparatus and procedures, especially for making centrifuge measurements with minimal compaction of the samples. -from Authors

FaceSheet Push-off Tests to Determine Composite Sandwich Toughness at Cryogenic Temperatures

NASA Technical Reports Server (NTRS)

Gates, Thomas S.; Herring, Helen M.

2001-01-01

A new novel test method, associated analysis, and experimental procedures are developed to investigate the toughness of the facesheet-to-core interface of a sandwich material at cryogenic temperatures. The test method is designed to simulate the failure mode associated with facesheet debonding from high levels of gas pressure in the sandwich core. The effects of specimen orientation are considered, and the results of toughness measurements are presented. Comparisons are made between room and liquid nitrogen (-196 C) test temperatures. It was determined that the test method is insensitive to specimen facesheet orientation and strain energy release rate increases with a decrease in the test temperature.

Rating the strength of coal mine roof rocks. Information circular/1996

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

Molinda, G.M.; Mark, C.

1996-05-01

The Ferm pictoral classification of coal measure rocks is widely utilized in coalfield exploration. Although extremely useful as an alternative to conventional geologic description, no material properties are provided that would be suitable for engineering solutions. To remedy this problem, the USBM has tested over 30 common coal measure roof rock types for axial and bedding strength. More than 1,300 individual point load tests have been conducted on core from 8 different coal mines representing the full range of common coal measure rocks. The USBM core and roof exposure properties database has been merged with the picture classification to provide,more » for the first time, a simple, clear guide from field identification of core to the associated mechanical strength of the rock. For 33 of the most common roof rocks, the axial and diametral point load strength, as well as the ultimate unit rating, is overprinted onto the photograph.« less

Application of ATHLET/DYN3D coupled codes system for fast liquid metal cooled reactor steady state simulation

NASA Astrophysics Data System (ADS)

Ivanov, V.; Samokhin, A.; Danicheva, I.; Khrennikov, N.; Bouscuet, J.; Velkov, K.; Pasichnyk, I.

2017-01-01

In this paper the approaches used for developing of the BN-800 reactor test model and for validation of coupled neutron-physic and thermohydraulic calculations are described. Coupled codes ATHLET 3.0 (code for thermohydraulic calculations of reactor transients) and DYN3D (3-dimensional code of neutron kinetics) are used for calculations. The main calculation results of reactor steady state condition are provided. 3-D model used for neutron calculations was developed for start reactor BN-800 load. The homogeneous approach is used for description of reactor assemblies. Along with main simplifications, the main reactor BN-800 core zones are described (LEZ, MEZ, HEZ, MOX, blankets). The 3D neutron physics calculations were provided with 28-group library, which is based on estimated nuclear data ENDF/B-7.0. Neutron SCALE code was used for preparation of group constants. Nodalization hydraulic model has boundary conditions by coolant mass-flow rate for core inlet part, by pressure and enthalpy for core outlet part, which can be chosen depending on reactor state. Core inlet and outlet temperatures were chosen according to reactor nominal state. The coolant mass flow rate profiling through the core is based on reactor power distribution. The test thermohydraulic calculations made with using of developed model showed acceptable results in coolant mass flow rate distribution through the reactor core and in axial temperature and pressure distribution. The developed model will be upgraded in future for different transient analysis in metal-cooled fast reactors of BN type including reactivity transients (control rods withdrawal, stop of the main circulation pump, etc.).

Evaluation of two cold thermoregulatory models for prediction of core temperature during exercise in cold water.

PubMed

Castellani, John W; O'Brien, Catherine; Tikuisis, Peter; Sils, Ingrid V; Xu, Xiaojiang

2007-12-01

Cold thermoregulatory models (CTM) have primarily been developed to predict core temperature (T(core)) responses during sedentary immersion. Few studies have examined their efficacy to predict T(core) during exercise cold exposure. The purpose of this study was to compare observed T(core) responses during exercise in cold water with the predicted T(core) from a three-cylinder (3-CTM) and a six-cylinder (6-CTM) model, adjusted to include heat production from exercise. A matrix of two metabolic rates (0.44 and 0.88 m/s walking), two water temperatures (10 and 15 degrees C), and two immersion depths (chest and waist) were used to elicit different rates of T(core) changes. Root mean square deviation (RMSD) and nonparametric Bland-Altman tests were used to test for acceptable model predictions. Using the RMSD criterion, the 3-CTM did not fit the observed data in any trial, whereas the 6-CTM fit the data (RMSD less than standard deviation) in four of eight trials. In general, the 3-CTM predicted a rapid decline in core temperature followed by a plateau. For the 6-CTM, the predicted T(core) appeared relatively tight during the early part of immersion, but was much lower during the latter portions of immersion, accounting for the nonagreement between RMSD and SD values. The 6-CTM was rerun with no adjustment for exercise metabolism, and core temperature and heat loss predictions were tighter. In summary, this study demonstrated that both thermoregulatory models designed for sedentary cold exposure, currently, cannot be extended for use during partial immersion exercise in cold water. Algorithms need to be developed to better predict heat loss during exercise in cold water.

Humidity effects on soluble core mechanical and thermal properties (polyvinyl alcohol/microballoon composite) type CG extendospheres, volume 2

NASA Technical Reports Server (NTRS)

1993-01-01

This document constitutes the final report for the study of humidity effects and loading rate on soluble core (PVA/MB composite material) mechanical and thermal properties under Contract No. 100345. This report describes test results procedures employed, and any unusual occurrences or specific observations associated with this test program. The primary objective of this work was to determine if cured soluble core filler material regains its tensile and compressive strength after exposure to high humidity conditions and following a drying cycle. Secondary objectives include measurements of tensile and compressive modulus, and Poisson's ratio, and coefficient of thermal expansion (CTE) for various moisture exposure states. A third objective was to compare the mechanical and thermal properties of the composite using 'SG' and 'CG' type extendospheres. The proposed facility for the manufacture of soluble cores at the Yellow Creek site incorporates no capability for the control of humidity. Recent physical property tests performed with the soluble core filler material showed that prolonged exposure to high humidity significantly degradates in strength. The purpose of these tests is to determine if the product, process or facility designs require modification to avoid imparting a high risk condition to the ASRM.

Teacher perceptions of high school students underachievement in science

NASA Astrophysics Data System (ADS)

Gopalsingh, Bhagyalakshmi

Low high school graduation rates continue to be a challenge in American public education. The pressure to meet the demands of adequate yearly progress (AYP) under the No Child Left behind Act of 2001 has led to an achievement gap in student performance between science and other core subjects, namely English, math, and social studies, on the Georgia High School Graduation Test (GHSGT). GHSGT statistics have consistently reflected a lower science pass percentage compared with other core subjects on the test. The objective of this nonexperimental, quantitative study was to analyze teacher perceptions on reasons for student science underachievement on the GHSGT. A self-developed questionnaire based on Bloom's taxonomy model was administered to 115 high school core subject teachers of a single school district. Analyses of variance (ANOVA) and chi-square tests were used to test hypotheses. Results confirmed that teachers perceived that (a) students demonstrated a low rate of proficiency in science because science demands higher cognitive skills, (b) less emphasis was placed on science because it is a non-AYP indicator, and (c) making science an AYP indicator will optimize student science achievement. Based on results, recommendations were made to promote the integration of English, math, and social studies curriculum with science curriculum to enable students to transfer learned skills and information across subjects. The potential benefits of outcome of this study include (a) providing critical insight for policy makers and educational practitioners to understand the impact of science underachievement on graduation rates, and (b) raising student science achievement to improve graduation rates.

Lightweight Low Force Rotary Percussive Coring Tool for Planetary Applications

NASA Technical Reports Server (NTRS)

Hironaka, Ross; Stanley, Scott

2010-01-01

A prototype low-force rotary-percussive rock coring tool for use in acquiring samples for geological surveys in future planetary missions was developed. The coring tool could eventually enable a lightweight robotic system to operate from a relatively small (less than 200 kg) mobile or fixed platform to acquire and cache Mars or other planetary rock samples for eventual return to Earth for analysis. To gain insight needed to design an integrated coring tool, the coring ability of commercially available coring bits was evaluated for effectiveness of varying key parameters: weight-on-bit, rotation speed, percussive rate and force. Trade studies were performed for different methods of breaking a core at its base and for retaining the core in a sleeve to facilitate sample transfer. This led to a custom coring tool design which incorporated coring, core breakage, core retention, and core extraction functions. The coring tool was tested on several types of rock and demonstrated the overall feasibility of this approach for robotic rock sample acquisition.

Improved method for measuring water imbibition rates on low-permeability porous media

USGS Publications Warehouse

Humphrey, M.D.; Istok, J.D.; Flint, L.E.; Flint, A.L.

1996-01-01

Existing methods for measuring water imbibition rates are inadequate when imbibition rates are small (e.g., clay soils and many igneous rocks). We developed an improved laboratory method for performing imbibition measurements on soil or rock cores with a wide range of hydraulic properties. Core specimens are suspended from an electronic strain gauge (load cell) in a closed chamber while maintaining the lower end of the core in contact with a free water surface in a constant water level reservoir. The upper end of the core is open to the atmosphere. During imbibition, mass increase of the core is recorded continuously by a datalogger that converts the load cell voltage signal into mass units using a calibration curve. Computer automation allows imbibition rate measurement on as many as eight cores simultaneously and independently. Performance of each component of the imbibition apparatus was evaluated using a set of rock cores (2.5 cm in diameter and 2-5 cm in length) from a single lithostratigraphic unit composed of non-to-moderately welded ash-flow tuff (a glass-rich pyroclastic rock partially fused by heat and pressure) with porosities ranging from 0.094 to 0.533 m3 m-3. Reproducibility of sample handling and testing procedures was demonstrated using replicate measurements. Precision and accuracy of load cell measurements were assessed using mass balance calculations and indicated agreement within a few tenths of a percent of total mass. Computed values of sorptivity, S, ranged from 8.83 x 10-6 to 4.55 x 10-4 m s-0.5. The developed method should prove useful for measuring imbibition rates on a wide range of porous materials.

Lead Coolant Test Facility Systems Design, Thermal Hydraulic Analysis and Cost Estimate

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

Soli Khericha; Edwin Harvego; John Svoboda

2012-01-01

The Idaho National Laboratory prepared a preliminary technical and functional requirements (T&FR), thermal hydraulic design and cost estimate for a lead coolant test facility. The purpose of this small scale facility is to simulate lead coolant fast reactor (LFR) coolant flow in an open lattice geometry core using seven electrical rods and liquid lead or lead-bismuth eutectic coolant. Based on review of current world lead or lead-bismuth test facilities and research needs listed in the Generation IV Roadmap, five broad areas of requirements were identified as listed: (1) Develop and Demonstrate Feasibility of Submerged Heat Exchanger; (2) Develop and Demonstratemore » Open-lattice Flow in Electrically Heated Core; (3) Develop and Demonstrate Chemistry Control; (4) Demonstrate Safe Operation; and (5) Provision for Future Testing. This paper discusses the preliminary design of systems, thermal hydraulic analysis, and simplified cost estimate. The facility thermal hydraulic design is based on the maximum simulated core power using seven electrical heater rods of 420 kW; average linear heat generation rate of 300 W/cm. The core inlet temperature for liquid lead or Pb/Bi eutectic is 4200 C. The design includes approximately seventy-five data measurements such as pressure, temperature, and flow rates. The preliminary estimated cost of construction of the facility is $3.7M (in 2006 $). It is also estimated that the facility will require two years to be constructed and ready for operation.« less

A new scale for disaster nursing core competencies: Development and psychometric testing.

PubMed

Al Thobaity, Abdulellah; Williams, Brett; Plummer, Virginia

2016-02-01

All nurses must have core competencies in preparing for, responding to and recovering from a disaster. In the Kingdom of Saudi Arabia (KSA), as in many other countries, disaster nursing core competencies are not fully understood and lack reliable, validated tools. Thus, it is imperative to develop a scale for exploring disaster nursing core competencies, roles and barriers in the KSA. This study's objective is to develop a valid, reliable scale that identifies and explores core competencies of disaster nursing, nurses' roles in disaster management and barriers to developing disaster nursing in the KSA. This study developed a new scale testing its validity and reliability. A principal component analysis (PCA) was used to develop and test psychometric properties of the new scale. The PCA used a purposive sample of nurses from emergency departments in two hospitals in the KSA. Participants rated 93 paper-based, self-report questionnaire items from 1 to 10 on a Likert scale. PCA using Varimax rotation was conducted to explore factors emerging from responses. The study's participants were 132 nurses (66% response rate). PCA of the 93 questionnaire items revealed 49 redundant items (which were deleted) and 3 factors with eigenvalues of >1. The remaining 44 items accounted for 77.3% of the total variance. The overall Cronbach's alpha was 0.96 for all factors: 0.98 for Factor 1, 0.92 for Factor 2 and 0.86 for Factor 3. This study provided a validated, reliable scale for exploring nurses' core competencies, nurses' roles and barriers to developing disaster nursing in the KSA. The new scale has many implications, such as for improving education, planning and curricula. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Test prediction for the German PKL Test K5A using RELAP4/MOD6

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

Chen, Y.S.; Haigh, W.S.; Sullivan, L.H.

RELAP4/MOD6 is the most recent modification in the series of RELAP4 computer programs developed to describe the thermal-hydraulic conditions attendant to postulated transients in light water reactor systems. The major new features in RELAP4/MOD6 include best-estimate pressurized water reactor (PWR) reflood transient analytical models for core heat transfer, local entrainment, and core vapor superheat, and a new set of heat transfer correlations for PWR blowdown and reflood. These new features were used for a test prediction of the Kraftwerk Union three-loop PRIMAR KREISLAUF (PKL) Reflood Test K5A. The results of the prediction were in good agreement with the experimental thermalmore » and hydraulic system data. Comparisons include heater rod surface temperature, system pressure, mass flow rates, and core mixture level. It is concluded that RELAP4/MOD6 is capable of accurately predicting transient reflood phenomena in the 200% cold-leg break test configuration of the PKL reflood facility.« less

Atomistic Design of CdSe/CdS Core-Shell Quantum Dots with Suppressed Auger Recombination.

PubMed

Jain, Ankit; Voznyy, Oleksandr; Hoogland, Sjoerd; Korkusinski, Marek; Hawrylak, Pawel; Sargent, Edward H

2016-10-12

We design quasi-type-II CdSe/CdS core-shell colloidal quantum dots (CQDs) exhibiting a suppressed Auger recombination rate. We do so using fully atomistic tight-binding wave functions and microscopic Coulomb interactions. The recombination rate as a function of the core and shell size and shape is tested against experiments. Because of a higher density of deep hole states and stronger hole confinement, Auger recombination is found to be up to six times faster for positive trions compared to negative ones in 4 nm core/10 nm shell CQDs. Soft-confinement at the interface results in weak suppression of Auger recombination compared to same-bandgap sharp-interface CQDs. We find that the suppression is due to increased volume of the core resulting in delocalization of the wave functions, rather than due to soft-confinement itself. We show that our results are consistent with previous effective mass models with the same system parameters. Increasing the dot volume remains the most efficient way to suppress Auger recombination. We predict that a 4-fold suppression of Auger recombination can be achieved in 10 nm CQDs by increasing the core volume by using rodlike cores embedded in thick shells.

Clinical efficacy of anti-glycopeptidolipid-core IgA test for diagnosing Mycobacterium avium complex infection in lung.

PubMed

Numata, Takanori; Araya, Jun; Yoshii, Yutaka; Shimizu, Kenichiro; Hara, Hiromichi; Nakayama, Katsutoshi; Kuwano, Kazuyoshi

2015-11-01

It is difficult to verify the bacteriological diagnosis of Mycobacterium avium complex (MAC) infection. The anti-glycopeptidolipid (GPL)-core IgA antibody test was recently developed as a diagnostic method for MAC pulmonary disease. Only a few studies evaluate its clinical efficacy. We conducted retrospective evaluations of clinical characteristics of patients suspected of MAC infection to explore the usefulness of the anti-GPL-core IgA antibody test. We retrospectively evaluated 296 patients who were suspected to have MAC infection and underwent anti-GPL-core IgA antibody test between March 2013 and July 2014 in Jikei University hospital. A total of 29 patients were diagnosed with 'definite MAC' based on the American Thoracic Society (ATS) criteria with multiple identifications of MAC. On the other hand, 106 patients were diagnosed with other pulmonary diseases than MAC. The sensitivity and specificity of anti-GPL-core IgA antibody test for MAC diagnosis were 58.6% and 98.1%, respectively. The definite MAC group showed no significant differences in strains, treatment history or number of segments involved. The duration of MAC disease in the positive-antibody group was significantly longer than in the negative-antibody group (P = 0.046). A significant increase in the false-negative rate was observed in patients with malignant disease (P = 0.029). The anti-GPL-core IgA antibody test demonstrated high sensitivity and specificity for the diagnosis of MAC infection especially in patients without malignant diseases. © 2015 Asian Pacific Society of Respirology.

Measurement of net nitrogen and phosphorus mineralization in wetland soils using a modification of the resin-core technique

USGS Publications Warehouse

Noe, Gregory B.

2011-01-01

A modification of the resin-core method was developed and tested for measuring in situ soil N and P net mineralization rates in wetland soils where temporal variation in bidirectional vertical water movement and saturation can complicate measurement. The modified design includes three mixed-bed ion-exchange resin bags located above and three resin bags located below soil incubating inside a core tube. The two inner resin bags adjacent to the soil capture NH4+, NO3-, and soluble reactive phosphorus (SRP) transported out of the soil during incubation; the two outer resin bags remove inorganic nutrients transported into the modified resin core; and the two middle resin bags serve as quality-control checks on the function of the inner and outer resin bags. Modified resin cores were incubated monthly for a year along the hydrogeomorphic gradient through a floodplain wetland. Only small amounts of NH4+, NO3-, and SRP were found in the two middle resin bags, indicating that the modified resin-core design was effective. Soil moisture and pH inside the modified resin cores typically tracked changes in the surrounding soil abiotic environment. In contrast, use of the closed polyethylene bag method provided substantially different net P and N mineralization rates than modified resin cores and did not track changes in soil moisture or pH. Net ammonification, nitrifi cation, N mineralization, and P mineralization rates measured using modified resin cores varied through space and time associated with hydrologic, geomorphic, and climatic gradients in the floodplain wetland. The modified resin-core technique successfully characterized spatiotemporal variation of net mineralization fluxes in situ and is a viable technique for assessing soil nutrient availability and developing ecosystem budgets.

Distinct Processes Drive Diversification in Different Clades of Gesneriaceae.

PubMed

Roalson, Eric H; Roberts, Wade R

2016-07-01

Using a time-calibrated phylogenetic hypothesis including 768 Gesneriaceae species (out of [Formula: see text]3300 species) and more than 29,000 aligned bases from 26 gene regions, we test Gesneriaceae for diversification rate shifts and the possible proximal drivers of these shifts: geographic distributions, growth forms, and pollination syndromes. Bayesian Analysis of Macroevolutionary Mixtures analyses found five significant rate shifts in Beslerieae, core Nematanthus, core Columneinae, core Streptocarpus, and Pacific Cyrtandra These rate shifts correspond with shifts in diversification rates, as inferred by Binary State Speciation and Extinction Model and Geographic State Speciation and Extinction model, associated with hummingbird pollination, epiphytism, unifoliate growth, and geographic area. Our results suggest that diversification processes are extremely variable across Gesneriaceae clades with different combinations of characters influencing diversification rates in different clades. Diversification patterns between New and Old World lineages show dramatic differences, suggesting that the processes of diversification in Gesneriaceae are very different in these two geographic regions. © The Author(s) 2016. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of core-to-dentin thickness ratio on the biaxial flexural strength, reliability, and fracture mode of bilayered materials of zirconia core (Y-TZP) and veneer indirect composite resins.

PubMed

Su, Naichuan; Liao, Yunmao; Zhang, Hai; Yue, Li; Lu, Xiaowen; Shen, Jiefei; Wang, Hang

2017-01-01

Indirect composite resins (ICR) are promising alternatives as veneering materials for zirconia frameworks. The effects of core-to-dentin thickness ratio (C/Dtr) on the mechanical property of bilayered veneer ICR/yttria-tetragonal zirconia polycrystalline (Y-TZP) core disks have not been previously studied. The purpose of this in vitro study was to assess the effects of C/Dtr on the biaxial flexural strength, reliability, and fracture mode of bilayered veneer ICR/ Y-TZP core disks. A total of 180 bilayered 0.6-mm-thick composite resin disks in core material and C/Dtr of 2:1, 1:1, and 1:2 were tested with either core material placed up or placed down for piston-on-3-ball biaxial flexural strength. The mean biaxial flexural strength, Weibull modulus, and fracture mode were measured to evaluate the variation trend of the biaxial flexural strength, reliability, and fracture mode of the bilayered disks with various C/Dtr. One-way analysis of variance (ANOVA) and chi-square tests were used to evaluate the variation tendency of fracture mode with the C/Dtr or material placed down during testing (α=.05). Light microscopy was used to identify the fracture mode. The mean biaxial flexural strength and reliability improved with the increase in C/Dtr when specimens were tested with the core material either up and down, and depended on the materials that were placed down during testing. The rates of delamination, Hertzian cone cracks, subcritical radial cracks, and number of fracture fragments partially depended on the C/Dtr and the materials that were placed down during testing. The biaxial flexural strength, reliability, and fracture mode in bilayered structures of Y-TZP core and veneer ICR depend on both the C/Dtr and the material that was placed down during testing. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Changes in heart rate variability during the induction and decay of heat acclimation.

PubMed

Flouris, Andreas D; Poirier, Martin P; Bravi, Andrea; Wright-Beatty, Heather E; Herry, Christophe; Seely, Andrew J; Kenny, Glen P

2014-10-01

We evaluated the changes in core temperature, heart rate, and heart rate variability (HRV) during the induction and decay of heat acclimation. Ten males (23 ± 3 years; 79.5 ± 3.5 kg; 15.2 ± 4.5 percent body fat; 51.13 ± 4.61 mLO(2)∙kg(-1)∙min(-1) peak oxygen uptake) underwent a 14-day heat acclimation protocol comprising of 90-min cycling at ~50 % peak oxygen uptake at 40 °C and ~20 % relative humidity. Core temperature, heart rate, and 102 HRV measures were recorded during a heat tolerance test conducted at baseline (day 0) and at the end of the induction (day 14) and decay (day 28) phases. Heat acclimation resulted in significantly reduced core temperature [rectal (χ (2) = 1298.14, p < 0.001); esophageal (χ (2) = 1069.88, p < 0.001)] and heart rate (χ (2) = 1230.17, p < 0.001). Following the decay phase, 26, 40, and 60 % of the heat acclimation-induced reductions in rectal temperature, esophageal temperature, and heart rate, respectively, were lost. Heat acclimation was accompanied by profound and broad changes in HRV: at the end of the induction phase, 75 of the 102 variability measures computed were significantly different (p < 0.001), compared to only 47 of the 102 at the end of the decay phase. Heat acclimation is accompanied by reduced core temperature, significant bradycardia, and marked alterations in HRV, which we interpret as being related to vagal dominance. The observed changes in core temperature persist for at least 2 weeks of non-exposure to heat, while the changes in heart rate and HRV decay faster and are only partly evident after 2 weeks of non-exposure to heat.

IMPLICATIONS OF RAPID CORE ROTATION IN RED GIANTS FOR INTERNAL ANGULAR MOMENTUM TRANSPORT IN STARS

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

Tayar, Jamie; Pinsonneault, Marc H., E-mail: tayar.1@osu.edu

2013-09-20

Core rotation rates have been measured for red giant stars using asteroseismology. These data, along with helioseismic measurements and open cluster spin-down studies, provide powerful clues about the nature and timescale for internal angular momentum transport in stars. We focus on two cases: the metal-poor red giant KIC 7341231 ({sup O}tto{sup )} and intermediate-mass core helium burning stars. For both, we examine limiting case studies for angular momentum coupling between cores and envelopes under the assumption of rigid rotation on the main sequence. We discuss the expected pattern of core rotation as a function of mass and radius. In themore » case of Otto, strong post-main-sequence coupling is ruled out and the measured core rotation rate is in the range of 23-33 times the surface value expected from standard spin-down models. The minimum coupling timescale (0.17-0.45 Gyr) is significantly longer than that inferred for young open cluster stars. This implies ineffective internal angular momentum transport in early first ascent giants. By contrast, the core rotation rates of evolved secondary clump stars are found to be consistent with strong coupling given their rapid main-sequence rotation. An extrapolation to the white dwarf regime predicts rotation periods between 330 and 0.0052 days, depending on mass and decoupling time. We identify two key ingredients that explain these features: the presence of a convective core and inefficient angular momentum transport in the presence of larger mean molecular weight gradients. Observational tests that can disentangle these effects are discussed.« less

Embedded binaries and their dense cores

NASA Astrophysics Data System (ADS)

Sadavoy, Sarah I.; Stahler, Steven W.

2017-08-01

We explore the relationship between young, embedded binaries and their parent cores, using observations within the Perseus Molecular Cloud. We combine recently published Very Large Array observations of young stars with core properties obtained from Submillimetre Common-User Bolometer Array 2 observations at 850 μm. Most embedded binary systems are found towards the centres of their parent cores, although several systems have components closer to the core edge. Wide binaries, defined as those systems with physical separations greater than 500 au, show a tendency to be aligned with the long axes of their parent cores, whereas tight binaries show no preferred orientation. We test a number of simple, evolutionary models to account for the observed populations of Class 0 and I sources, both single and binary. In the model that best explains the observations, all stars form initially as wide binaries. These binaries either break up into separate stars or else shrink into tighter orbits. Under the assumption that both stars remain embedded following binary break-up, we find a total star formation rate of 168 Myr-1. Alternatively, one star may be ejected from the dense core due to binary break-up. This latter assumption results in a star formation rate of 247 Myr-1. Both production rates are in satisfactory agreement with current estimates from other studies of Perseus. Future observations should be able to distinguish between these two possibilities. If our model continues to provide a good fit to other star-forming regions, then the mass fraction of dense cores that becomes stars is double what is currently believed.

Sizing Single Cantilever Beam Specimens for Characterizing Facesheet/Core Peel Debonding in Sandwich Structure

NASA Technical Reports Server (NTRS)

Ratcliffe, James G.

2010-01-01

This technical publication details part of an effort focused on the development of a standardized facesheet/core peel debonding test procedure. The purpose of the test is to characterize facesheet/core peel in sandwich structure, accomplished through the measurement of the critical strain energy release rate associated with the debonding process. Following an examination of previously developed tests and a recent evaluation of a selection of these methods, a single cantilever beam (SCB) specimen was identified as being a promising candidate for establishing such a standardized test procedure. The objective of the work described here was to begin development of a protocol for conducting a SCB test that will render the procedure suitable for standardization. To this end, a sizing methodology was developed to ensure appropriate SCB specimen dimensions are selected for a given sandwich system. Application of this method to actual sandwich systems yielded SCB specimen dimensions that would be practical for use. This study resulted in the development of a practical SCB specimen sizing method, which should be well-suited for incorporation into a standardized testing protocol.

Core courses in public health laboratory science and practice: findings from 2006 and 2011 surveys.

PubMed

DeBoy, John M; Beck, Angela J; Boulton, Matthew L; Kim, Deborah H; Wichman, Michael D; Luedtke, Patrick F

2013-01-01

We identified academic training courses or topics most important to the careers of U.S. public health, environmental, and agricultural laboratory (PHEAL) scientist-managers and directors, and determined what portions of the national PHEAL workforce completed these courses. We conducted electronic national surveys in 2006 and 2011, and analyzed data using numerical ranking, Chi-square tests comparing rates, and Spearman's formula measuring rank correlation. In 2006, 40 of 50 PHEAL directors identified 56 course topics as either important, useful, or not needed for someone in their position. These course topics were then ranked to provide a list of 31 core courses. In 2011, 1,659 of approximately 5,555 PHEAL scientific and technical staff, using a subset of 25 core courses, evidenced higher core course completion rates associated with higher-level job classification, advanced academic degree, and age. The 2011 survey showed that 287 PHEAL scientist-managers and directors, on average, completed 37.7% (n=5/13) of leadership/managerial core courses and 51.7% (n=6/12) of scientific core courses. For 1,659 laboratorians in all scientific and technical classifications, core-subject completion rates were higher in local laboratories (42.8%, n=11/25) than in state (36.0%, n=9/25), federal (34.4%, n=9/25), and university (31.2%, n=8/25) laboratories. There is a definable range of scientific, leadership, and managerial core courses needed by PHEAL scientist-managers and directors to function effectively in their positions. Potential PHEAL scientist-managers and directors need greater and continuing access to these courses, and academic and practice entities supporting development of this workforce should adopt curricula and core competencies aligned with these course topics.

Core Courses in Public Health Laboratory Science and Practice: Findings from 2006 and 2011 Surveys

PubMed Central

Beck, Angela J.; Boulton, Matthew L.; Kim, Deborah H.; Wichman, Michael D.; Luedtke, Patrick F.

2013-01-01

Objectives We identified academic training courses or topics most important to the careers of U.S. public health, environmental, and agricultural laboratory (PHEAL) scientist-managers and directors, and determined what portions of the national PHEAL workforce completed these courses. Methods We conducted electronic national surveys in 2006 and 2011, and analyzed data using numerical ranking, Chi-square tests comparing rates, and Spearman's formula measuring rank correlation. Results In 2006, 40 of 50 PHEAL directors identified 56 course topics as either important, useful, or not needed for someone in their position. These course topics were then ranked to provide a list of 31 core courses. In 2011, 1,659 of approximately 5,555 PHEAL scientific and technical staff, using a subset of 25 core courses, evidenced higher core course completion rates associated with higher-level job classification, advanced academic degree, and age. The 2011 survey showed that 287 PHEAL scientist-managers and directors, on average, completed 37.7% (n=5/13) of leadership/managerial core courses and 51.7% (n=6/12) of scientific core courses. For 1,659 laboratorians in all scientific and technical classifications, core-subject completion rates were higher in local laboratories (42.8%, n=11/25) than in state (36.0%, n=9/25), federal (34.4%, n=9/25), and university (31.2%, n=8/25) laboratories. Conclusions There is a definable range of scientific, leadership, and managerial core courses needed by PHEAL scientist-managers and directors to function effectively in their positions. Potential PHEAL scientist-managers and directors need greater and continuing access to these courses, and academic and practice entities supporting development of this workforce should adopt curricula and core competencies aligned with these course topics. PMID:23997310

Testing Mechanisms and Scales of Equilibrium Using Textural and Compositional Analysis of Porphyroblasts in Rocks with Heterogeneous Garnet Distributions

NASA Astrophysics Data System (ADS)

Ruthven, R. C.; Ketcham, R. A.; Kelly, E. D.

2015-12-01

Three-dimensional textural analysis of garnet porphyroblasts and electron microprobe analyses can, in concert, be used to pose novel tests that challenge and ultimately increase our understanding of metamorphic crystallization mechanisms. Statistical analysis of high-resolution X-ray computed tomography (CT) data of garnet porphyroblasts tells us the degree of ordering or randomness of garnets, which can be used to distinguish the rate-limiting factors behind their nucleation and growth. Electron microprobe data for cores, rims, and core-to-rim traverses are used as proxies to ascertain porphyroblast nucleation and growth rates, and the evolution of sample composition during crystallization. MnO concentrations in garnet cores serve as a proxy for the relative timing of nucleation, and rim concentrations test the hypothesis that MnO is in equilibrium sample-wide during the final stages of crystallization, and that concentrations have not been greatly altered by intracrystalline diffusion. Crystal size distributions combined with compositional data can be used to quantify the evolution of nucleation rates and sample composition during crystallization. This study focuses on quartzite schists from the Picuris Mountains with heterogeneous garnet distributions consisting of dense and sparse layers. 3D data shows that the sparse layers have smaller, less euhedral garnets, and petrographic observations show that sparse layers have more quartz and less mica than dense layers. Previous studies on rocks with homogeneously distributed garnet have shown that crystallization rates are diffusion-controlled, meaning that they are limited by diffusion of nutrients to growth and nucleation sites. This research extends this analysis to heterogeneous rocks to determine nucleation and growth rates, and test the assumption of rock-wide equilibrium for some major elements, among a set of compositionally distinct domains evolving in mm- to cm-scale proximity under identical P-T conditions.

Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction

NASA Astrophysics Data System (ADS)

Zapartas, E.; de Mink, S. E.; Izzard, R. G.; Yoon, S.-C.; Badenes, C.; Götberg, Y.; de Koter, A.; Neijssel, C. J.; Renzo, M.; Schootemeijer, A.; Shrotriya, T. S.

2017-05-01

Most massive stars, the progenitors of core-collapse supernovae, are in close binary systems and may interact with their companion through mass transfer or merging. We undertake a population synthesis study to compute the delay-time distribution of core-collapse supernovae, that is, the supernova rate versus time following a starburst, taking into account binary interactions. We test the systematic robustness of our results by running various simulations to account for the uncertainties in our standard assumptions. We find that a significant fraction, %, of core-collapse supernovae are "late", that is, they occur 50-200 Myr after birth, when all massive single stars have already exploded. These late events originate predominantly from binary systems with at least one, or, in most cases, with both stars initially being of intermediate mass (4-8 M⊙). The main evolutionary channels that contribute often involve either the merging of the initially more massive primary star with its companion or the engulfment of the remaining core of the primary by the expanding secondary that has accreted mass at an earlier evolutionary stage. Also, the total number of core-collapse supernovae increases by % because of binarity for the same initial stellar mass. The high rate implies that we should have already observed such late core-collapse supernovae, but have not recognized them as such. We argue that φ Persei is a likely progenitor and that eccentric neutron star - white dwarf systems are likely descendants. Late events can help explain the discrepancy in the delay-time distributions derived from supernova remnants in the Magellanic Clouds and extragalactic type Ia events, lowering the contribution of prompt Ia events. We discuss ways to test these predictions and speculate on the implications for supernova feedback in simulations of galaxy evolution.

Using imagery to identify and characterise core beliefs in women with bulimia nervosa, dieting and non-dieting women.

PubMed

Somerville, Kate; Cooper, Myra

2007-12-01

Women with bulimia nervosa (BN), dieters and non-dieting control participants were questioned about spontaneous imagery linked to concern with food and eating, weight and shape. The downward arrow technique was used to access any associated negative or core beliefs, which were examined for belief, distress and content. A semi-structured interview with open and closed questions was used. Negative self (core) beliefs were successfully accessed, and responses to the interview items had good test-retest and good inter-rater reliability. Patients with BN reported significantly more negative self (core) beliefs than those in the other two groups. Only a very small number of core beliefs about other people or the world in general were reported. Emotional belief ratings appeared to be higher overall than rational belief ratings. Patient's negative self-beliefs contained themes of "self-value", followed by "failure", "self-control" and "physical attractiveness", in descending order of frequency. The findings are discussed in relation to existing research, and implications for cognitive theories of bulimia nervosa and clinical practice are briefly discussed.

Spatial and temporal distributions of surface mass balance between Concordia and Vostok stations, Antarctica, from combined radar and ice core data: first results and detailed error analysis

NASA Astrophysics Data System (ADS)

Le Meur, Emmanuel; Magand, Olivier; Arnaud, Laurent; Fily, Michel; Frezzotti, Massimo; Cavitte, Marie; Mulvaney, Robert; Urbini, Stefano

2018-05-01

Results from ground-penetrating radar (GPR) measurements and shallow ice cores carried out during a scientific traverse between Dome Concordia (DC) and Vostok stations are presented in order to infer both spatial and temporal characteristics of snow accumulation over the East Antarctic Plateau. Spatially continuous accumulation rates along the traverse are computed from the identification of three equally spaced radar reflections spanning about the last 600 years. Accurate dating of these internal reflection horizons (IRHs) is obtained from a depth-age relationship derived from volcanic horizons and bomb testing fallouts on a DC ice core and shows a very good consistency when tested against extra ice cores drilled along the radar profile. Accumulation rates are then inferred by accounting for density profiles down to each IRH. For the latter purpose, a careful error analysis showed that using a single and more accurate density profile along a DC core provided more reliable results than trying to include the potential spatial variability in density from extra (but less accurate) ice cores distributed along the profile. The most striking feature is an accumulation pattern that remains constant through time with persistent gradients such as a marked decrease from 26 mm w.e. yr-1 at DC to 20 mm w.e. yr-1 at the south-west end of the profile over the last 234 years on average (with a similar decrease from 25 to 19 mm w.e. yr-1 over the last 592 years). As for the time dependency, despite an overall consistency with similar measurements carried out along the main East Antarctic divides, interpreting possible trends remains difficult. Indeed, error bars in our measurements are still too large to unambiguously infer an apparent time increase in accumulation rate. For the proposed absolute values, maximum margins of error are in the range 4 mm w.e. yr-1 (last 234 years) to 2 mm w.e. yr-1 (last 592 years), a decrease with depth mainly resulting from the time-averaging when computing accumulation rates.

Grinding efficiency of abutment tooth with both dentin and core composite resin on axial plane.

PubMed

Miho, Otoaki; Sato, Toru; Matsukubo, Takashi

2015-01-01

The purpose of this study was to evaluate grinding efficiency in abutment teeth comprising both dentin and core composite resin in the axial plane. Grinding was performed over 5 runs at two loads (0.5 or 0.25 N) and two feed rates (1 or 2 mm/sec). The grinding surface was observed with a 3-D laser microscope. Tomographic images of the grinding surfaces captured perpendicular to the feed direction were also analyzed. Using a non-ground surface as a reference, areas comprising only dentin, both dentin and core composite resin, or only core composite resin were analyzed to determine the angle of the grinding surface. Composite resins were subjected to the Vickers hardness test and scanning electron microscopy. Data were statistically analyzed using a one-way analysis of variance and multiple comparison tests. Multiple regression analysis was performed for load, feed rate, and Vickers hardness of the build-up material depending on number of runs. When grinding was performed at a constant load and feed rate, a greater grinding angle was observed in areas comprising both dentin and composite resin or only composite resin than in areas consisting of dentin alone. A correlation was found between machinability and load or feed rate in areas comprising both dentin and composite resin or composite resin alone, with a particularly high correlation being observed between machinability and load. These results suggest that great caution should be exercised in a clinical setting when the boundary between the dentin and composite resin is to be ground, as the angle of the grinding surface changes when the rotating diamond point begins grinding the composite resin.

AN ADVANCED LEAKAGE SCHEME FOR NEUTRINO TREATMENT IN ASTROPHYSICAL SIMULATIONS

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

Perego, A.; Cabezón, R. M.; Käppeli, R., E-mail: albino.perego@physik.tu-darmstadt.de

We present an Advanced Spectral Leakage (ASL) scheme to model neutrinos in the context of core-collapse supernovae (CCSNe) and compact binary mergers. Based on previous gray leakage schemes, the ASL scheme computes the neutrino cooling rates by interpolating local production and diffusion rates (relevant in optically thin and thick regimes, respectively) separately for discretized values of the neutrino energy. Neutrino trapped components are also modeled, based on equilibrium and timescale arguments. The better accuracy achieved by the spectral treatment allows a more reliable computation of neutrino heating rates in optically thin conditions. The scheme has been calibrated and tested against Boltzmannmore » transport in the context of Newtonian spherically symmetric models of CCSNe. ASL shows a very good qualitative and a partial quantitative agreement for key quantities from collapse to a few hundreds of milliseconds after core bounce. We have proved the adaptability and flexibility of our ASL scheme, coupling it to an axisymmetric Eulerian and to a three-dimensional smoothed particle hydrodynamics code to simulate core collapse. Therefore, the neutrino treatment presented here is ideal for large parameter-space explorations, parametric studies, high-resolution tests, code developments, and long-term modeling of asymmetric configurations, where more detailed neutrino treatments are not available or are currently computationally too expensive.« less

Heat storage in Asian elephants during submaximal exercise: behavioral regulation of thermoregulatory constraints on activity in endothermic gigantotherms.

PubMed

Rowe, M F; Bakken, G S; Ratliff, J J; Langman, V A

2013-05-15

Gigantic size presents both opportunities and challenges in thermoregulation. Allometric scaling relationships suggest that gigantic animals have difficulty dissipating metabolic heat. Large body size permits the maintenance of fairly constant core body temperatures in ectothermic animals by means of gigantothermy. Conversely, gigantothermy combined with endothermic metabolic rate and activity likely results in heat production rates that exceed heat loss rates. In tropical environments, it has been suggested that a substantial rate of heat storage might result in a potentially lethal rise in core body temperature in both elephants and endothermic dinosaurs. However, the behavioral choice of nocturnal activity might reduce heat storage. We sought to test the hypothesis that there is a functionally significant relationship between heat storage and locomotion in Asian elephants (Elephas maximus), and model the thermoregulatory constraints on activity in elephants and a similarly sized migratory dinosaur, Edmontosaurus. Pre- and post-exercise (N=37 trials) measurements of core body temperature and skin temperature, using thermography were made in two adult female Asian elephants at the Audubon Zoo in New Orleans, LA, USA. Over ambient air temperatures ranging from 8 to 34.5°C, when elephants exercised in full sun, ~56 to 100% of active metabolic heat production was stored in core body tissues. We estimate that during nocturnal activity, in the absence of solar radiation, between 5 and 64% of metabolic heat production would be stored in core tissues. Potentially lethal rates of heat storage in active elephants and Edmontosaurus could be behaviorally regulated by nocturnal activity.

Flow tests of a single fuel element coolant channel for a compact fast reactor for space power

NASA Technical Reports Server (NTRS)

Springborn, R. H.

1971-01-01

Water flow tests were conducted on a single-fuel-element cooling channel for a nuclear concept to be used for space power. The tests established a method for measuring coolant flow rate which is applicable to water flow testing of a complete mockup of the reference reactor. The inlet plenum-to-outlet plenum pressure drop, which approximates the overall core pressure drop, was measured and correlated with flow rate. This information can be used for reactor coolant flow and heat transfer calculations. An analytical study of the flow characteristics was also conducted.

Determination of dryout localization using a five-equation model of annular flow for boiling in minichannels

NASA Astrophysics Data System (ADS)

Wajs, Jan; Mikielewicz, Dariusz

2017-03-01

Detailed studies have suggested that the critical heat flux in the form of dryout in minichannels occurs when the combined effects of entrainment, deposition, and evaporation of the film make the film flow rate go gradually and smoothly to zero. Most approaches so far used the mass balance equation for the liquid film with appropriate formulations for the rate of deposition and entrainment respectively. It must be acknowledged that any discrepancy in determination of deposition and entrainment rates, together with cross-correlations between them, leads to the loss of accuracy of model predictions. Conservation equations relating the primary parameters are established for the liquid film and vapor core. The model consists of three mass balance equations, for liquid in the film as well as two-phase core and the gas phase itself. These equations are supplemented by the corresponding momentum equations for liquid in the film and the two-phase core. Applicability of the model has been tested on some experimental data.

The treatment of mixing in core helium-burning models - III. Suppressing core breathing pulses with a new constraint on overshoot

NASA Astrophysics Data System (ADS)

Constantino, Thomas; Campbell, Simon W.; Lattanzio, John C.

2017-12-01

Theoretical predictions for the core helium burning phase of stellar evolution are highly sensitive to the uncertain treatment of mixing at convective boundaries. In the last few years, interest in constraining the uncertain structure of their deep interiors has been renewed by insights from asteroseismology. Recently, Spruit proposed a limit for the rate of growth of helium-burning convective cores based on the higher buoyancy of material ingested from outside the convective core. In this paper we test the implications of such a limit for stellar models with a range of initial mass and metallicity. We find that the constraint on mixing beyond the Schwarzschild boundary has a significant effect on the evolution late in core helium burning, when core breathing pulses occur and the ingestion rate of helium is fastest. Ordinarily, core breathing pulses prolong the core helium burning lifetime to such an extent that models are at odds with observations of globular cluster populations. Across a wide range of initial stellar masses (0.83 ≤ M/M⊙ ≤ 5), applying the Spruit constraint reduces the core helium burning lifetime because core breathing pulses are either avoided or their number and severity reduced. The constraint suggested by Spruit therefore helps to resolve significant discrepancies between observations and theoretical predictions. Specifically, we find improved agreement for R2 (the observed ratio of asymptotic giant branch to horizontal branch stars in globular clusters), the luminosity difference between these two groups, and in asteroseismology, the mixed-mode period spacing detected in red clump stars in the Kepler field.

Posttest data analysis and assessment of TRAC-BD1/MOD1 with data from a Full Integral Simulation Test (FIST) power transient experiment

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

Wheatley, P.D.; Wagner, K.C.

The FIST power transient test 6PMC2 was analyzed to further the understanding of the FIST facility and provide an assessment of TRAC-BD1/MOD1. FIST power transient 6PMC2 investigated the thermal-hydraulic response following inadvertent closure of the main steam isolation valve and the subsequent failure of the reactor to scram. Failure of the high pressure core spray system was also assumed, resulting on only the reactor core isolation cooling flow for inventory makeup during the transient. The experiment was a sensitivity study with relatively high core power and low makeup rates. This study provides one of the first opportunities to assess TRAC-BD1/MOD1more » under power transient and natural circulation conditions with data from a facility with prototypical BWR geometry. The power transient test was analyzed with emphasis on the following phenomena; (a) the system pressure response, (b) the natural circulation flows and rates, and (c) the heater rod cladding temperature response. Based on the results of this study, TRAC-BD1/MOD1 can be expected to calculate the thermal-hydraulic behavior of a BWR during a power transient.« less

Hydro-mechanical properties of pressure core sediments recovered from the Krishna-Godavari Basin during India's National Gas Hydrate Program Expedition NGHP-02

NASA Astrophysics Data System (ADS)

Yoneda, J.; Oshima, M.; Kida, M.; Kato, A.; Konno, Y.; Jin, Y.; Waite, W. F.; Jang, J.; Kumar, P.; Tenma, N.

2017-12-01

Pressure coring and analysis technology allows for gas hydrate to be recovered from the deep seabed, transferred to the laboratory and characterized while continuously maintaining gas hydrate stability. For this study, dozens of hydrate-bearing pressure core sediment subsections recovered from the Krishna-Godavari Basin during India's National Gas Hydrate Program Expedition NGHP-02 were tested with Pressure Core Non-destructive Analysis Tools (PNATs) through a collaboration between Japan and India. PNATs, originally developed by AIST as a part of the Japanese National hydrate research program (MH21, funded by METI) conducted permeability, compression and consolidation tests under various effective stress conditions, including the in situ stress state estimated from downhole bulk density measurements. At the in situ effective stress, gas hydrate-bearing sediments had an effective permeability range of 0.01-10mD even at pore-space hydrate saturations above 60%. Permeability increased by 10 to 100 times after hydrate dissociation at the same effective stress, but these post-dissociation gains were erased when effective stress was increased from in situ values ( 1 MPa) to 10MPa in a simulation of the depressurization method for methane extraction from hydrate. Vertical-to-horizontal permeability anisotropy was also investigated. First-ever multi-stage loading tests and strain-rate alternation compression tests were successfully conducted for evaluating sediment strengthening dependence on the rate and magnitude of effective confining stress changes. In addition, oedometer tests were performed up to 40MPa of consolidation stress to simulate the depressurization method in ultra-deep sea environments. Consolidation curves measured with and without gas hydrate were investigated over a wide range of effective confining stresses. Compression curves for gas hydrate-bearing sediments were convex downward due to high hydrate saturations. Consolidation tests show that, regardless of the consolidation history with hydrate in place, the consolidation behavior after dissociation will first return to, then follow, the original normal consolidation curve for the hydrate-free host sediment.

On Geomagnetism and Paleomagnetism

NASA Technical Reports Server (NTRS)

Voorhies, Coerte V.

1998-01-01

A statistical description of Earth's broad scale, core-source magnetic field has been developed and tested. The description features an expected, or mean, spatial magnetic power spectrum that is neither "flat" nor "while" at any depth, but is akin to spectra advanced by Stevenson and McLeod. This multipole spectrum describes the magnetic energy range; it is not steep enough for Gubbins' magnetic dissipation range. Natural variations of core multipole powers about their mean values are to be expected over geologic time and are described via trial probability distribution functions that neither require nor prohibit magnetic isotropy. The description is thus applicable to core-source dipole and low degree non-dipole fields despite axial dipole anisotropy. The description is combined with main field models of modem satellite and surface geomagnetic measurements to make testable predictions of: (1) the radius of Earth's core, (2) mean paleomagnetic field intensity, and (3) the mean rates and durations of both dipole power excursions and durable axial dipole reversals. The predicted core radius is 0.7% above the 3480 km seismologic value. The predicted root mean square paleointensity (35.6 mu T) and mean Virtual Axial Dipole Moment (about 6.2 lx 1022 Am(exp 2)) are within the range of various mean paleointensity estimates. The predicted mean rate of dipole power excursions, as defined by an absolute dipole moment <20% of the 1980 value, is 9.04/Myr and 14% less than obtained by analysis of a 4 Myr paleointensity record. The predicted mean rate of durable axial dipole reversals (2.26/Myr) is 2.3% more than established by the polarity time-scale for the past 84 Myr. The predicted mean duration of axial dipole reversals (5533 yr) is indistinguishable from an observational value. The accuracy of these predictions demonstrates the power and utility of the description, which is thought to merit further development and testing. It is suggested that strong stable stratification of Earth's uppermost outer core leads to a geologically long interval of no dipole reversals and a very nearly axisymmetric field outside the core. Statistical descriptions of other planetary magnetic fields are outlined.

Psychometric properties of the Finnish version of the Young Person's Clinical Outcomes in Routine Evaluation (YP-CORE) questionnaire.

PubMed

Gergov, Vera; Lahti, Jari; Marttunen, Mauri; Lipsanen, Jari; Evans, Chris; Ranta, Klaus; Laitila, Aarno; Lindberg, Nina

2017-05-01

An increasing need exists for suitable measures to evaluate treatment outcome in adolescents. YP-CORE is a pan-theoretical brief questionnaire developed for this purpose, but it lacks studies in different cultures or languages. To explore the acceptability, factor structure, reliability, validity, and sensitivity to change of the Finnish translation of YP-CORE. The study was conducted at the Department of Adolescent Psychiatry, Helsinki University Central Hospital. A Finnish translation was prepared by a team of professionals and adolescents. A clinical sample of 104 patients was asked to complete the form together with BDI-21 and BAI, and 92 of them filled the forms again after a 3-month treatment. Analysis included acceptability, confirmatory factor analysis, internal and test-re-test reliability, concurrent validity, influence of gender and age, and criteria for reliable change. YP-CORE was well accepted, and the rate of missing values was low. Internal consistency (α = 0.83-.92) and test-re-test reliability were good (r = 0.69), and the results of CFA supported a one-factor model. YP-CORE showed good concurrent validity against two widely used symptom-specific measures (r = 0.62-0.87). Gender had a moderately strong effect on the scores (d = 0.67), but the effect of age was not as evident. The measure was sensitive to change, showing a larger effect size (d = 0.55) than in the BDI-21 and BAI (d = 0.31-0.50). The results show that the translation of YP-CORE into Finnish has been successful, the YP-CORE has good psychometric properties, and the measure could be taken into wider use in clinical settings for outcome measurement in adolescents.

Operational performance of the three bean salad control algorithm on the ACRR (Annular Core Research Reactor)

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

Ball, R.M.; Madaras, J.J.; Trowbridge, F.R. Jr.

Experimental tests on the Annular Core Research Reactor have confirmed that the Three-Bean-Salad'' control algorithm based on the Pontryagin maximum principle can change the power of a nuclear reactor many decades with a very fast startup rate and minimal overshoot. The paper describes the results of simulations and operations up to 25 MW and 87 decades per minute. 3 refs., 4 figs., 1 tab.

Characterizing Mobile/Less-Mobile Porosity and Solute Exchange in Dual-Domain Media Using Tracer Experiments and Electrical Measurements in a Hassler-Type Core Holder

NASA Astrophysics Data System (ADS)

Falzone, S.; Slater, L. D.; Day-Lewis, F. D.; Parker, B. L.; Keating, K.; Robinson, J.

2017-12-01

Mass transfer is the process by which solute is retained in less-mobile porosity domains, and later released into the mobile porosity domain. This process is often responsible for the slow arrival and gradual release of contaminants and solute tracers. Recent studies have outlined methods using dual-domain mass transfer (DDMT) models for characterizing this phenomenon. These models use the non-linear relationship of bulk (σb) and fluid (σf) conductivity, collected from electrical methods during tracer experiments, to characterize the less-mobile/mobile porosity ratio (β) and the mass-transfer rate coefficient (α). DDMT models use the hysteretic σb-σf relationship observed while solute tracers are injected and then flushed from a sample media. Due to limitations in observing the hysteretic σb-σf relationship, this method has not been used to characterize low permeability samples. We have developed an experimental method for testing porous rock cores that allows us to develop a fundamental understanding of contaminant storage and release in consolidated rock. We test the approach on cores from sedimentary rock sites where mass transfer is expected to occur between hydraulically connected fractures and the adjacent low permeability rock matrix. Our method uses a Hassler-type core holder, designed to apply confining pressure around the outside of a sample core, which hydraulically isolates the sample core, allowing water to be injected into it at increased pressures. The experimental apparatus was also designed to measure σb with spectral induced polarization (SIP) measurements, and σf from a sampling port located at the center of the core. Cores were initially saturated with a solution with high electrical conductivity ( 80000 μS/cm). DI water was then injected into the cores at elevated pressures (>60 psi) and the saturating solution was flushed from the cores, in order to generate flow rates fast enough to capture the non-linear σb-σf relationship expected when DDMT occurs. Our initial results demonstrate the existence of a non-linear σb-σf relationship indicative of DDMT for a tight sandstone core from a contaminated fractured rock site. Integrating the electrical results with known physical characteristics of the cores, we are able to quantify the mass transfer characteristics of the cores.

Capabilities and Testing of the Fission Surface Power Primary Test Circuit (FSP-PTC)

NASA Technical Reports Server (NTRS)

Garber, Anne E.

2007-01-01

An actively pumped alkali metal flow circuit, designed and fabricated at the NASA Marshall Space Flight Center, is currently undergoing testing in the Early Flight Fission Test Facility (EFF-TF). Sodium potassium (NaK), which was used in the SNAP-10A fission reactor, was selected as the primary coolant. Basic circuit components include: simulated reactor core, NaK to gas heat exchanger, electromagnetic (EM) liquid metal pump, liquid metal flowmeter, load/drain reservoir, expansion reservoir, test section, and instrumentation. Operation of the circuit is based around a 37-pin partial-array core (pin and flow path dimensions are the same as those in a full core), designed to operate at 33 kWt. NaK flow rates of greater than 1 kg/sec may be achieved, depending upon the power applied to the EM pump. The heat exchanger provides for the removal of thermal energy from the circuit, simulating the presence of an energy conversion system. The presence of the test section increases the versatility of the circuit. A second liquid metal pump, an energy conversion system, and highly instrumented thermal simulators are all being considered for inclusion within the test section. This paper summarizes the capabilities and ongoing testing of the Fission Surface Power Primary Test Circuit (FSP-PTC).

Toward an Improved Hypersonic Engine Seal

NASA Technical Reports Server (NTRS)

Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; DeMange,Jeffrey J.; Taylor, Shawn C.

2003-01-01

High temperature, dynamic seals are required in advanced engines to seal the perimeters of movable engine ramps for efficient, safe operation in high heat flux environments at temperatures from 2000 to 2500 F. Current seal designs do not meet the demanding requirements for future engines, so NASA s Glenn Research Center (GRC) is developing advanced seals to overcome these shortfalls. Two seal designs and two types of seal preloading devices were evaluated in a series of compression tests at room temperature and 2000 F and flow tests at room temperature. Both seals lost resiliency with repeated load cycling at room temperature and 2000 F, but seals with braided cores were significantly more flexible than those with cores composed of uniaxial ceramic fibers. Flow rates for the seals with cores of uniaxial fibers were lower than those for the seals with braided cores. Canted coil springs and silicon nitride compression springs showed promise conceptually as potential seal preloading devices to help maintain seal resiliency.

Results from Testing of Two Rotary Percussive Drilling Systems

NASA Technical Reports Server (NTRS)

Kriechbaum, Kristopher; Brown, Kyle; Cady, Ian; von der Heydt, Max; Klein, Kerry; Kulczycki, Eric; Okon, Avi

2010-01-01

The developmental test program for the MSL (Mars Science Laboratory) rotary percussive drill examined the e ect of various drill input parameters on the drill pene- tration rate. Some of the input parameters tested were drill angle with respect to gravity and percussive impact energy. The suite of rocks tested ranged from a high strength basalt to soft Kaolinite clay. We developed a hole start routine to reduce high sideloads from bit walk. The ongoing development test program for the IMSAH (Integrated Mars Sample Acquisition and Handling) rotary percussive corer uses many of the same rocks as the MSL suite. An additional performance parameter is core integrity. The MSL development test drill and the IMSAH test drill use similar hardware to provide rotation and percussion. However, the MSL test drill uses external stabilizers, while the IMSAH test drill does not have external stabilization. In addition the IMSAH drill is a core drill, while the MSL drill uses a solid powdering bit. Results from the testing of these two related drilling systems is examined.

Novel Method of Estimating Metabolic Rates of Soldiers Engaged in Chemical Biological Defense Training

DTIC Science & Technology

2016-12-01

Simplified example of estimating metabolic rate from core temperature using the SCENARIO thermoregulatory model. 7 4 Edgewood training site, Day 1, core... temperature (TC) and metabolic rate (Ṁ). 10 5 Edgewood training site, Day 2, core temperature (TC) and metabolic rate (Ṁ). 11 6 Hayward...training site, Day 1, core temperature (TC) and metabolic rate (Ṁ). 12 7 Hayward training site, Day 2, core temperature (TC) and metabolic rate (Ṁ). 13

Reference point detection for camera-based fingerprint image based on wavelet transformation.

PubMed

Khalil, Mohammed S

2015-04-30

Fingerprint recognition systems essentially require core-point detection prior to fingerprint matching. The core-point is used as a reference point to align the fingerprint with a template database. When processing a larger fingerprint database, it is necessary to consider the core-point during feature extraction. Numerous core-point detection methods are available and have been reported in the literature. However, these methods are generally applied to scanner-based images. Hence, this paper attempts to explore the feasibility of applying a core-point detection method to a fingerprint image obtained using a camera phone. The proposed method utilizes a discrete wavelet transform to extract the ridge information from a color image. The performance of proposed method is evaluated in terms of accuracy and consistency. These two indicators are calculated automatically by comparing the method's output with the defined core points. The proposed method is tested on two data sets, controlled and uncontrolled environment, collected from 13 different subjects. In the controlled environment, the proposed method achieved a detection rate 82.98%. In uncontrolled environment, the proposed method yield a detection rate of 78.21%. The proposed method yields promising results in a collected-image database. Moreover, the proposed method outperformed compare to existing method.

Preparation of hollow mesoporous carbon spheres and their performances for electrochemical applications

NASA Astrophysics Data System (ADS)

Ariyanto, T.; Zhang, G. R.; Kern, A.; Etzold, B. J. M.

2018-03-01

Hollow carbon materials have received intensive attention for energy storage/conversion applications due to their attractive properties of high conductivity, high surface area, large void and short diffusion pathway. In this work, a novel hollow mesoporous material based on carbide-derived carbon (CDC) is presented. CDC is a new class of carbon material synthesized by the selective extraction of metals from metal carbides. With a two-stage extraction procedure of carbides with chlorine, firstly hybrid core-shell carbon particles were synthesized, i.e. mesoporous/graphitic carbon shells covering microporous/amorphous carbon cores. The amorphous cores were then selectively removed from particles by a careful oxidative treatment utilizing its low thermal characters while the more stable carbon shells remained, thus resulting hollow particles. The characterization methods (e.g. N2 sorption, Raman spectroscopy, temperature-programmed oxidation and SEM) proved the successful synthesis of the aspired material. In electric double-layer capacitor (EDLC) testing, this novel hollow core material showed a remarkable enhancement of EDLC’s rate handling ability (75% at a high scan rate) with respect to an entirely solid-mesoporous material. Furthermore, as a fuel cell catalyst support the material showed higher Pt mass activity (a factor of 1.8) compared to a conventional carbon support for methanol oxidation without noticeably decreasing activity in a long-term testing. Therefore, this carbon nanostructure shows great promises as efficient electrode materials for energy storage and conversion systems.

Oscillatory erosion and transport flume with superimposed unidirectional flow

DOEpatents

Jepsen, Richard A.; Roberts, Jesse D.

2004-01-20

A method and apparatus for measuring erosion rates of sediments and at high shear stresses due to complex wave action with, or without, a superimposed unidirectional current. Water is forced in a channel past an exposed sediment core sample, which erodes sediments when a critical shear stress has been exceeded. The height of the core sample is adjusted during testing so that the sediment surface remains level with the bottom of the channel as the sediments erode. Complex wave action is simulated by driving tandom piston/cylinder mechanisms with computer-controlled stepper motors. Unidirectional flow, forced by a head difference between two open tanks attached to each end of the channel, may be superimposed on to the complex wave action. Sediment traps may be used to collect bedload sediments. The total erosion rate equals the change in height of the sediment core sample divided by a fixed period of time.

Posttest data analysis of FIST experimental TRAC-BD1/MOD1 power transient experiment

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

Wheatley, P.D.; Wagner, K.C.

The FIST power transient test 6PMC2 was analyzed to further the understanding of the FIST facility and provide an assessment of TRAC-BD1/MOD1. FIST power transient 6PMC2 investigated the thermal-hydraulic response following inadvertent closure of the main steam isolation valve and the subsequent failure of the reactor to scram. Failure of the high pressure core spray system was also assumed, resulting in only the reactor core isolation cooling flow for inventory makeup during the transient. The experiment was a sensitivity study with relatively high core power and low makeup rates. This study provides one of the first opportunities to assess TRAC-BD1/MOD1more » under power transient and natural circulation conditions with data from a facility with prototypical BWR geometry. The power transient test was analyzed with emphasis on the following phenomena: (a) the system pressure response, (b) the natural circulation flows and rates, and (c) the heater rod cladding temperature response. Based on the results of this study, TRAC-BD1/MOD1 can be expected to calculate the thermal-hydraulic behavior of a BWR during a power transient.« less

Comparison of fine-needle aspiration and core needle biopsy under ultrasonographic guidance for detecting malignancy and for the tissue-specific diagnosis of salivary gland tumors.

PubMed

Eom, H-J; Lee, J H; Ko, M-S; Choi, Y J; Yoon, R G; Cho, K J; Nam, S Y; Baek, J H

2015-06-01

Diagnostic test accuracy studies for ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy have shown inconclusive results due to their heterogenous study designs. Our aim was to compare the diagnostic accuracy of ultrasonography-guided fine-needle aspiration versus ultrasonography-guided core needle biopsy for detecting malignant tumors of the salivary gland and for the tissue-specific diagnosis of salivary gland tumors in a single tertiary hospital. This retrospective study was approved by our institutional review board and informed consent was waived. Four hundred twelve patients who underwent ultrasonography-guided fine-needle aspiration (n = 155) or ultrasonography-guided core needle biopsy (n = 257) with subsequent surgical confirmation or clinical follow-up were enrolled. We compared the diagnostic accuracy of ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy regarding malignant salivary gland tumors and the correct tissue-specific diagnosis of benign and malignant tumors. We also tested the difference between these procedures according to the operator's experience and lesion characteristics. The inconclusive rates of ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy were 19% and 4%, respectively (P < .001). The overall accuracy of ultrasonography-guided core needle biopsy for diagnosing malignant tumors was significantly higher than that of ultrasonography-guided fine-needle aspiration (P = .024). The correct tissue-specific diagnosis rates of ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy were 95% versus 97% for benign tumors (P = .648) and 67% versus 80% for malignant tumors (P = .310). Trainees showed significantly lower accuracy with ultrasonography-guided fine-needle aspiration than with ultrasonography-guided core needle biopsy for diagnosing malignant tumors (P = .021). There was no difference between the diagnostic accuracy of ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy according to the internal composition of the lesions. There were no complications requiring intervention or hospitalization in our patients. Ultrasonography-guided core needle biopsy is superior to ultrasonography-guided fine-needle aspiration in detecting and characterizing malignant tumors of the salivary gland and could emerge as the diagnostic method of choice for patients presenting with a salivary gland mass. © 2015 by American Journal of Neuroradiology.

Modeling analysis of pulsed magnetization process of magnetic core based on inverse Jiles-Atherton model

NASA Astrophysics Data System (ADS)

Liu, Yi; Zhang, He; Liu, Siwei; Lin, Fuchang

2018-05-01

The J-A (Jiles-Atherton) model is widely used to describe the magnetization characteristics of magnetic cores in a low-frequency alternating field. However, this model is deficient in the quantitative analysis of the eddy current loss and residual loss in a high-frequency magnetic field. Based on the decomposition of magnetization intensity, an inverse J-A model is established which uses magnetic flux density B as an input variable. Static and dynamic core losses under high frequency excitation are separated based on the inverse J-A model. Optimized parameters of the inverse J-A model are obtained based on particle swarm optimization. The platform for the pulsed magnetization characteristic test is designed and constructed. The hysteresis curves of ferrite and Fe-based nanocrystalline cores at high magnetization rates are measured. The simulated and measured hysteresis curves are presented and compared. It is found that the inverse J-A model can be used to describe the magnetization characteristics at high magnetization rates and to separate the static loss and dynamic loss accurately.

Final Research Performance Report - Small Molecular Associative Carbon Dioxide (CO 2) Thickeners for Improved Mobility Control

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

Enick, Robert M.

The initial objective of this project was to promote the application of a CO 2 thickener for improved mobility control during CO 2 EOR based on solubility tests, viscosity tests, and core floods. Ultimately, it was demonstrated that the CO 2-soluble polymeric thickeners are much better suited for use a CO 2-soluble conformance control agents for diverting the flow of CO 2 away from thief zones. Our team generated several effective small molecule CO 2 thickeners with ARPA-e funding. Unfortunately, none of these small molecule thickeners could dissolve in CO 2 without the addition of unacceptably large amounts of hexanemore » or toluene as a co-solvent Therefore none were viable candidates for the core flooding studies associated with NETL award. Therefore during the entire core flood testing program associated with this NETL award, our team used only the most promising polymeric CO 2 thickener, a polyfluoroacrylate (PFA). In order to produce an environmentally benign polymer, the monomer used to make the new polymers used in this study was a fluoroacrylate that contains only six fluorinated carbons. We verified CO 2 solubility with a phase behavior cell. The thickening potential of all polymer samples was substantiated with a falling ball viscometer and a falling cylinder viscometer at Pitt. Two different viscometers were used to determine the increase in CO 2 viscosity that could be achieved via the dissolution of PFA. Praxair, which has an interest in thickening CO 2 for pilot EOR projects and for waterless hydraulic fracturing, agreed to measure the viscosity of CO 2-PFA solutions at no cost to the project. Falling cylinder viscometery was conducted at Pitt in our windowed high pressure phase behavior cell. Both apparatuses indicated that at very low shear rates the CO 2 viscosity increased by a factor of roughly 3.5 when 1wt% PFA was dissolved in the CO 22. Our team also planned thickener concentrations and compositions at Pitt for the core tests that were conducted at Special Core Analysis Laboratories, Inc., (SCAL) in Midland, TX, where the ability for PFA to reduce CO 2 mobility in a core was then tested. During the beginning of these tests, the PFA polymer was then shown to impart reasonable improvements in mobility control during the SCAL core tests; as the CO 2-PFA solution displaced CO 2 from the core at a constant volumetric flow rate, the pressure drop increased as expected. However, as the test progressed, there was clear and surprising evidence of dramatic reductions in core permeability due to PFA adsorption, especially for sandstones. For example, as the CO 2-PFA solution displaced pure CO 2 from sandstone and limestone cores, the pressure drop increased by factors of multiple hundreds to over a thousand. It was subsequently demonstrated that the PFA injected into the core either (a) adsorbed strongly and irreversibly onto the rock surfaces, (b) deposited/precipitated within the rock, thereby blocking pores in a manner that could be dislodged by large changes in flow rate or flow direction, or (c) remained in solution and passed completely through the core. The loss of PFA to the porous media and the unacceptably large increases in pressure drop both indicated that PFA was inappropriate for CO 2 EOR mobility control, where thickener adsorption must be minimized and mobility reductions of only 10-100-fold are typically required. However, we realized that because the CO 2-PFA solution could greatly reduce the permeability of porous media, it could serve as a near wellbore conformance control agent for blocking “thief zones”, where adsorption is acceptable and dramatic increases in pressure drop are desirable. These effects were more dramatic for sandstone than for limestone. Therefore, these PFA fluoroacrylate polymers can serve as a CO 2-soluble conformance control agent for CO 2-EOR, especially in sandstone formations. This injection of a single phase solution of CO 2-PFA for permeability reduction is (to the best of our knowledge) the first report of a CO 2-soluble conformance control additive. We also demonstrated that the optimal strategy for using CO 2-PFA solutions for conformance control is analogous to the application of water-based polymeric gels; the CO 2-PFA solution should first be injected only in an isolated thief zone to induce dramatic reductions in permeability only in that thief zone, and then CO 2 should be injected into all of the zones. Finally, it was noted that given the propensity of PFA to adsorb onto sandstone, the adsorption of PFA from CO 2-PFA solutions onto cement surfaces promote the sealing of extremely fine cracks in casing cement.« less

Plasma core reactor simulations using RF uranium seeded argon discharges

NASA Technical Reports Server (NTRS)

Roman, W. C.

1976-01-01

Experimental results are described in which pure uranium hexafluoride was injected into an argon-confined, steady-state, RF-heated plasma to investigate characteristics of plasma core nuclear reactors. The 80 kW (13.56 MHz) and 1.2 MW (5.51 MHz) rf induction heater facilities were used to determine a test chamber flow scheme which offered best uranium confinement with minimum wall coating. The cylindrical fused-silica test chamber walls were 5.7-cm-ID by 10-cm-long. Test conditions included RF powers of 2-85 kW, chamber pressures of 1-12 atm, and uranium hexafluoride mass-flow rates of 0.005-0.13 g/s. Successful techniques were developed for fluid-mechanical confinement of RF-heated plasmas with pure uranium hexafluoride injection.

Modelling of magnetostriction of transformer magnetic core for vibration analysis

NASA Astrophysics Data System (ADS)

Marks, Janis; Vitolina, Sandra

2017-12-01

Magnetostriction is a phenomenon occurring in transformer core in normal operation mode. Yet in time, it can cause the delamination of magnetic core resulting in higher level of vibrations that are measured on the surface of transformer tank during diagnostic tests. The aim of this paper is to create a model for evaluating elastic deformations in magnetic core that can be used for power transformers with intensive vibrations in order to eliminate magnetostriction as a their cause. Description of the developed model in Matlab and COMSOL software is provided including restrictions concerning geometry and properties of materials, and the results of performed research on magnetic core anisotropy are provided. As a case study modelling of magnetostriction for 5-legged 200 MVA power transformer with the rated voltage of 13.8/137kV is conducted, based on which comparative analysis of vibration levels and elastic deformations is performed.

The failure rate of adhesively retained composite core build-ups in comparison with metal-added glass ionomer core build-ups.

PubMed

Stober, Thomas; Rammelsberg, P

2005-01-01

The purpose of this study was to evaluate the clinical performance of two adhesively retained composite core materials and compare them with a metal-added glass ionomer. The main objective evaluated was total or partial loss of build-ups during the treatment prior to crown cementation. In 187 patients, 315 vital and non-vital teeth were built up after randomisation with either Rebilda D (RD), Rebilda SC (RSC) or Ketac Silver Aplicap (KSA). The composites were applied in the total-etch-technique with the corresponding dentin bonding agent. The metal-added glass ionomer was used with a conditioner. One group of patients was treated by experienced dentists, the other by dental students, in order to evaluate the effects of different levels of experience. Data were analysed using Mann-Whitney-U-Test and binomial logistic regression. The early failure rate (partial or total loss) of core build-ups before crown cementation was significantly higher for KSA (28.8%), as compared to RSC (15.3%, p=0.037) and RD (15%, p=0.025). Most failures were observed during the removal of the temporary crowns. The rate of replacements was between 3.0 (RD/dentists) and 20.4% (KSA/students). Furthermore, we found that build-ups made by students had a significantly higher risk of loss than those made by dentists (p=0.028). Adhesively retained self-curing composites show a better clinical short-term performance and can be recommended as core build-up materials.

Urine tests for Down's syndrome screening.

PubMed

Alldred, S Kate; Guo, Boliang; Takwoingi, Yemisi; Pennant, Mary; Wisniewski, Susanna; Deeks, Jonathan J; Neilson, James P; Alfirevic, Zarko

2015-12-10

Down's syndrome occurs when a person has three copies of chromosome 21, or the specific area of chromosome 21 implicated in causing Down's syndrome, rather than two. It is the commonest congenital cause of mental disability and also leads to numerous metabolic and structural problems. It can be life-threatening, or lead to considerable ill health, although some individuals have only mild problems and can lead relatively normal lives. Having a baby with Down's syndrome is likely to have a significant impact on family life. The risk of a Down's syndrome affected pregnancy increases with advancing maternal age.Noninvasive screening based on biochemical analysis of maternal serum or urine, or fetal ultrasound measurements, allows estimates of the risk of a pregnancy being affected and provides information to guide decisions about definitive testing. Before agreeing to screening tests, parents need to be fully informed about the risks, benefits and possible consequences of such a test. This includes subsequent choices for further tests they may face, and the implications of both false positive and false negative screening tests (i.e. invasive diagnostic testing, and the possibility that a miscarried fetus may be chromosomally normal). The decisions that may be faced by expectant parents inevitably engender a high level of anxiety at all stages of the screening process, and the outcomes of screening can be associated with considerable physical and psychological morbidity. No screening test can predict the severity of problems a person with Down's syndrome will have. To estimate and compare the accuracy of first and second trimester urine markers for the detection of Down's syndrome. We carried out a sensitive and comprehensive literature search of MEDLINE (1980 to 25 August 2011), EMBASE (1980 to 25 August 2011), BIOSIS via EDINA (1985 to 25 August 2011), CINAHL via OVID (1982 to 25 August 2011), The Database of Abstracts of Reviews of Effectiveness (The Cochrane Library 2011, Issue 7), MEDION (25 August 2011), The Database of Systematic Reviews and Meta-Analyses in Laboratory Medicine (25 August 2011), The National Research Register (archived 2007), Health Services Research Projects in Progress database (25 August 2011). We studied reference lists and published review articles. Studies evaluating tests of maternal urine in women up to 24 weeks of gestation for Down's syndrome, compared with a reference standard, either chromosomal verification or macroscopic postnatal inspection. We extracted data as test positive or test negative results for Down's and non-Down's pregnancies allowing estimation of detection rates (sensitivity) and false positive rates (1-specificity). We performed quality assessment according to QUADAS (Quality Assessment of Diagnostic Accuracy Studies) criteria. We used hierarchical summary ROC (receiver operating characteristic) meta-analytical methods to analyse test performance and compare test accuracy. We performed analysis of studies allowing direct comparison between tests. We investigated the impact of maternal age on test performance in subgroup analyses. We included 19 studies involving 18,013 pregnancies (including 527 with Down's syndrome). Studies were generally of high quality, although differential verification was common with invasive testing of only high-risk pregnancies. Twenty-four test combinations were evaluated formed from combinations of the following seven different markers with and without maternal age: AFP (alpha-fetoprotein), ITA (invasive trophoblast antigen), ß-core fragment, free ßhCG (beta human chorionic gonadotrophin), total hCG, oestriol, gonadotropin peptide and various marker ratios. The strategies evaluated included three double tests and seven single tests in combination with maternal age, and one triple test, two double tests and 11 single tests without maternal age. Twelve of the 19 studies only evaluated the performance of a single test strategy while the remaining seven evaluated at least two test strategies. Two marker combinations were evaluated in more than four studies; second trimester ß-core fragment (six studies), and second trimester ß-core fragment with maternal age (five studies).In direct test comparisons, for a 5% false positive rate (FPR), the diagnostic accuracy of the double marker second trimester ß-core fragment and oestriol with maternal age test combination was significantly better (ratio of diagnostic odds ratio (RDOR): 2.2 (95% confidence interval (CI) 1.1 to 4.5), P = 0.02) (summary sensitivity of 73% (CI 57 to 85) at a cut-point of 5% FPR) than that of the single marker test strategy of second trimester ß-core fragment and maternal age (summary sensitivity of 56% (CI 45 to 66) at a cut-point of 5% FPR), but was not significantly better (RDOR: 1.5 (0.8 to 2.8), P = 0.21) than that of the second trimester ß-core fragment to oestriol ratio and maternal age test strategy (summary sensitivity of 71% (CI 51 to 86) at a cut-point of 5% FPR). Tests involving second trimester ß-core fragment and oestriol with maternal age are significantly more sensitive than the single marker second trimester ß-core fragment and maternal age, however, there were few studies. There is a paucity of evidence available to support the use of urine testing for Down's syndrome screening in clinical practice where alternatives are available.

Reconstruction of TiO2/MnO2-C nanotube/nanoflake core/shell arrays as high-performance supercapacitor electrodes

NASA Astrophysics Data System (ADS)

Xiong, Qinqin; Zheng, Cun; Chi, Hongzhong; Zhang, Jun; Ji, Zhenguo

2017-02-01

Construction of electrodes with fast reaction kinetics is of great importance for achieving advanced supercapacitors. Herein we report a facile combined synthetic strategy with atomic layer deposition (ALD) and electrodeposition to rationally fabricate nanotube/nanoflake core/shell arrays. ALD-TiO2 nanotubes are used as the skeleton core for assembly of electrodeposited MnO2-C nanoflake shells forming a core/shell structure. Highly porous architecture and good electrical conductivity are combined in this unique core/shell structure, resulting in fast ion/electron transfer. In tests of electrochemical performance, the TiO2/MnO2-C core/shell arrays are characterized as cathode for asymmetric supecapacitors and exhibit high specific capacitance (880 F g-1 at 2.5 A g-1), excellent rate properties (735 F g-1 at 30 A g-1) and good long-term cycling stability (94.3% capacitance retention after 20 000 cycles). The proposed electrode construction strategy is favorable for fabrication of other advanced supercapacitor electrodes.

Reconstruction of TiO2/MnO2-C nanotube/nanoflake core/shell arrays as high-performance supercapacitor electrodes.

PubMed

Xiong, Qinqin; Zheng, Cun; Chi, Hongzhong; Zhang, Jun; Ji, Zhenguo

2017-02-03

Construction of electrodes with fast reaction kinetics is of great importance for achieving advanced supercapacitors. Herein we report a facile combined synthetic strategy with atomic layer deposition (ALD) and electrodeposition to rationally fabricate nanotube/nanoflake core/shell arrays. ALD-TiO 2 nanotubes are used as the skeleton core for assembly of electrodeposited MnO 2 -C nanoflake shells forming a core/shell structure. Highly porous architecture and good electrical conductivity are combined in this unique core/shell structure, resulting in fast ion/electron transfer. In tests of electrochemical performance, the TiO 2 /MnO 2 -C core/shell arrays are characterized as cathode for asymmetric supecapacitors and exhibit high specific capacitance (880 F g -1 at 2.5 A g -1 ), excellent rate properties (735 F g -1 at 30 A g -1 ) and good long-term cycling stability (94.3% capacitance retention after 20 000 cycles). The proposed electrode construction strategy is favorable for fabrication of other advanced supercapacitor electrodes.

Flow Field and Acoustic Predictions for Three-Stream Jets

NASA Technical Reports Server (NTRS)

Simmons, Shaun Patrick; Henderson, Brenda S.; Khavaran, Abbas

2014-01-01

Computational fluid dynamics was used to analyze a three-stream nozzle parametric design space. The study varied bypass-to-core area ratio, tertiary-to-core area ratio and jet operating conditions. The flowfield solutions from the Reynolds-Averaged Navier-Stokes (RANS) code Overflow 2.2e were used to pre-screen experimental models for a future test in the Aero-Acoustic Propulsion Laboratory (AAPL) at the NASA Glenn Research Center (GRC). Flowfield solutions were considered in conjunction with the jet-noise-prediction code JeNo to screen the design concepts. A two-stream versus three-stream computation based on equal mass flow rates showed a reduction in peak turbulent kinetic energy (TKE) for the three-stream jet relative to that for the two-stream jet which resulted in reduced acoustic emission. Additional three-stream solutions were analyzed for salient flowfield features expected to impact farfield noise. As tertiary power settings were increased there was a corresponding near nozzle increase in shear rate that resulted in an increase in high frequency noise and a reduction in peak TKE. As tertiary-to-core area ratio was increased the tertiary potential core elongated and the peak TKE was reduced. The most noticeable change occurred as secondary-to-core area ratio was increased thickening the secondary potential core, elongating the primary potential core and reducing peak TKE. As forward flight Mach number was increased the jet plume region decreased and reduced peak TKE.

Assessment of multiple sources of anthropogenic and natural chemical inputs to a morphologically complex basin, Lake Mead, USA

USGS Publications Warehouse

Rosen, Michael R.; Van Metre, P.C.

2010-01-01

Lakes with complex morphologies and with different geologic and land-use characteristics in their sub-watersheds could have large differences in natural and anthropogenic chemical inputs to sub-basins in the lake. Lake Mead in southern Nevada and northern Arizona, USA, is one such lake. To assess variations in chemical histories from 1935 to 1998 for major sub-basins of Lake Mead, four sediment cores were taken from three different parts of the reservoir (two from Las Vegas Bay and one from the Overton Arm and Virgin Basin) and analyzed for major and trace elements, radionuclides, and organic compounds. As expected, anthropogenic contaminant inputs are greatest to Las Vegas Bay reflecting inputs from the Las Vegas urban area, although concentrations are low compared to sediment quality guidelines and to other USA lakes. One exception to this pattern was higher Hg in the Virgin Basin core. The Virgin Basin core is located in the main body of the lake (Colorado River channel) and is influenced by the hydrology of the Colorado River, which changed greatly with completion of Glen Canyon Dam upstream in 1963. Major and trace elements in the core show pronounced shifts in the early 1960s and, in many cases, gradually return to concentrations more typical of pre-1960s by the 1980s and 1990s, after the filling of Lake Powell. The Overton Arm is the sub-basin least effected by anthropogenic contaminant inputs but has a complex 137Cs profile with a series of large peaks and valleys over the middle of the core, possibly reflecting fallout from nuclear tests in the 1950s at the Nevada Test Site. The 137Cs profile suggests a much greater sedimentation rate during testing which we hypothesize results from greatly increased dust fall on the lake and Virgin and Muddy River watersheds. The severe drought in the southwestern USA during the 1950s might also have played a role in variations in sedimentation rate in all of the cores. ?? 2009.

Continuous-annealing method for producing a flexible, curved, soft magnetic amorphous alloy ribbon

NASA Astrophysics Data System (ADS)

Francoeur, Bruno; Couture, Pierre

2012-04-01

A method has been developed for continuous annealing of an amorphous alloy ribbon moving forward at several meters per second, giving a curved shape to the ribbon that remains flexible afterward and can be easily wound into a toroidal core with excellent soft magnetic properties. A heat pulse was applied by a compact system on a Metglas 2605HB1 ribbon moving forward at 5 m/s to initiate a thermal treatment at 460 °C, near crystallization onset. The treatment duration was less than 0.1 s, and the heating and cooling rates were above 10 000 °C/s, which helped preserve most of the alloy as-cast ductility state. Such high temperature rates were achieved by forcing a static contact between the moving ribbon and a temperature-controlled roller. A tensile stress and a series of bending configurations were applied on the moving ribbon during the treatment to induce the development of magnetic anisotropy and to obtain the desired natural curvature radius. The core losses at 60 Hz of a toroidal test core wound with the resulting ribbon are lower than the specific values reported by the alloy manufacturer. This method can be implemented at the casting plant for supplying a low-cost, ready-to-use ribbon, easy to handle and cut, for mass production of toroidal cores for distribution transformer kernels (core and coil only), pulse power cores, etc.

Experimental Evaluations of Selected Immersion Hypothermia Protection Equipment.

DTIC Science & Technology

1979-10-12

Temperature Response ............... 30 Figure 1-3 Estimated Survival Times for Average Men ..... 49 Figure 1-4 Metabolic Rate Response :Subject BS...51 Figure 1-5 Metabolic Rate Response : Subject GE ............... 52 Figure 1-6 Selected Elementary Movements ............... 58 Figure 1-7 Fatigue... responses to cold-Immersion, while wearing the test articles, could be observed or-vs over a narrow range of body core temperatures Involving the mildest

Measurements of erosion potential using Gust chamber in Yolo Bypass near Sacramento, California

USGS Publications Warehouse

Work, Paul A.; Schoellhamer, David H.

2018-04-27

This report describes work performed to quantify the erodibility of surface soils in the Yolo Bypass (Bypass) near Sacramento, California, for use in the California Department of Water Resources (DWR) Yolo Bypass D-MCM mercury model. The Bypass, when not serving as a floodway, is heavily utilized for agriculture. During flood events, surface water flows over the soil, resulting in the application of a shear stress to the soil. The shear stress is a function of flow speed and is often assumed to vary as the square of flow speed. Once the shear stress reaches a critical value, erosion commences, and the erosion rate typically increases with applied shear stress. The goal of the work described here was to quantify this process and how it varies throughout the major land uses found in the Yolo Bypass.Each of the major land uses found in the Bypass was targeted for sediment coring and two side-by-side cores, 10 centimeters in diameter, were extracted at each site for testing in a Gust erosion chamber. This device consists of a cylinder with a piston and cap installed to contain a sediment sample and overlying water. In most instances, coring was done with the cylinder, the piston and cap were installed, and testing commenced immediately. The cap at the top of the cylinder contains vanes to induce rotation of the flow and is driven by an electric motor, simulating the bed shear stress experienced by the soil in a flood event. Ambient water is introduced to the cylinder, passes through the device, and carries eroded sediment out of the chamber. The exiting water is tested for turbidity, and water samples obtained to relate turbidity to suspended sediment concentration are used to compute erosion rates for each of the applied shear stresses.The result for each sediment core is (1) definition of the critical shear stress required to initiate sediment erosion and (2) estimation of coefficients required to relate erosion rate to applied shear stress once this critical shear-stress threshold has been exceeded. These quantities were computed for each of the sites sampled. In total, 10 locations were sampled, representing 10 land uses ranging from wild and white rice fields to the flooded Liberty Island and the Toe Drain that receives runoff from much of the cultivated land (table 1).The Gust chamber test causes the erosion of a very small layer of sediment, typically less than a millimeter thick. The strength of the soil within this layer increases with depth, typically, and this soil strength versus depth is measured in the testing process.Results for each land use type tested are presented as the initial critical shear stress at which erosion began and the rate at which erosion increases as shear stress increases (table 2). Of the land use types sampled, irrigated pasture displayed the lowest critical shear stress, meaning that it required the smallest flow speed to initiate erosion. But in this case, the rate of increase of the subsequent erosion, given higher flow speeds, was small. The wild rice field samples exhibited a higher critical shear stress but also exhibited a much higher erosion rate once the critical shear stress was exceeded. The erosion rate for wild rice was about three times greater than that for white rice. Bear in mind that these results are based on only two cores tested per site, and variability between fields with the same crop could be significant. Approved digital data can be viewed and downloaded from ScienceBase, at https://doi.org/10.5066/F7BV7DQC. These results are being used to calculate erosion rates in the DWR Yolo Bypass D-MCM mercury model.The Toe Drain was very difficult to sample, owing to hard, consolidated sediments on the channel bed. On the first visit, two cores were obtained successfully, and testing revealed very different results. A second visit was made, but it was not possible to obtain cores suitable for testing with the coring equipment used. The available results suggest that Toe Drain soil is highly erodible (low critical shear stress and high erosion rate once initiated) despite being difficult to sample. As a collector of runoff, it also has the potential to accumulate soils eroded from adjacent areas, subsequent to storm events, as flows subside. This deposited material will typically be more erodible than the material that it lands on. The deposition and resuspension of material was not simulated in the testing described here because the applied shear stress increases monotonically during testing.The spatial distribution of mean grain size, loss on ignition, and percent fines of Yolo Bypass soils are also presented. Sediment sampling for this effort was performed by DWR; the U.S. Geological Survey (USGS) performed the sample analysis. These data should thus be considered provisional, but the remainder of the data presented here, and this report, have been through the formal U.S. Geological Survey review process.A separate effort has been made by others to develop numerical model results defining the spatially  varying, time-dependent hydrodynamics in the Yolo Bypass. These model results are being used to quantify shear stress on the soil surface, which together with the Gust chamber results shown here, are used for the DWR Yolo Bypass D-MCM mercury transport model to compute erosion rates for each time step.

Determining the Optimal Number of Core Needle Biopsy Passes for Molecular Diagnostics.

PubMed

Hoang, Nam S; Ge, Benjamin H; Pan, Lorraine Y; Ozawa, Michael G; Kong, Christina S; Louie, John D; Shah, Rajesh P

2018-03-01

The number of core biopsy passes required for adequate next-generation sequencing is impacted by needle cut, needle gauge, and the type of tissue involved. This study evaluates diagnostic adequacy of core needle lung biopsies based on number of passes and provides guidelines for other tissues based on simulated biopsies in ex vivo porcine organ tissues. The rate of diagnostic adequacy for pathology and molecular testing from lung biopsy procedures was measured for eight operators pre-implementation (September 2012-October 2013) and post-implementation (December 2013-April 2014) of a standard protocol using 20-gauge side-cut needles for ten core biopsy passes at a single academic hospital. Biopsy pass volume was then estimated in ex vivo porcine muscle, liver, and kidney using side-cut devices at 16, 18, and 20 gauge and end-cut devices at 16 and 18 gauge to estimate minimum number of passes required for adequate molecular testing. Molecular diagnostic adequacy increased from 69% (pre-implementation period) to 92% (post-implementation period) (p < 0.001) for lung biopsies. In porcine models, both 16-gauge end-cut and side-cut devices require one pass to reach the validated volume threshold to ensure 99% adequacy for molecular characterization, while 18- and 20-gauge devices require 2-5 passes depending on needle cut and tissue type. Use of 20-gauge side-cut core biopsy needles requires a significant number of passes to ensure diagnostic adequacy for molecular testing across all tissue types. To ensure diagnostic adequacy for molecular testing, 16- and 18-gauge needles require markedly fewer passes.

Thulium fiber laser lithotripsy using tapered fibers.

PubMed

Blackmon, Richard L; Irby, Pierce B; Fried, Nathaniel M

2010-01-01

The Thulium fiber laser has recently been tested as a potential alternative to the Holmium:YAG laser for lithotripsy. This study explores use of a short taper for expanding the Thulium fiber laser beam at the distal tip of a small-core fiber. Thulium fiber laser radiation with a wavelength of 1,908 nm, 10 Hz pulse rate, 70 mJ pulse energy, and 1-millisecond pulse duration was delivered through a 2-m-length fiber with 150-microm-core-input-end, 300-microm-core-output-end, and 5-mm-length taper, in contact with human uric acid (UA) and calcium oxalate monohydrate (COM) stones, ex vivo (n = 10 each). Stone mass loss, stone crater depths, fiber transmission losses, fiber burn-back, irrigation rates, and deflection through a flexible ureteroscope were measured for the tapered fiber and compared with conventional fibers. After delivery of 1,800 pulses through the tapered fiber, mass loss measured 12.7+/-2.6 mg for UA and 7.2+/-0.8 mg COM stones, comparable to conventional 100-microm-core fibers (12.6+/-2.5 mg for UA and 6.8+/-1.7 mg for COM stones). No transmission losses or burn-back occurred for the tapered fiber after 36,000 pulses, while a conventional 150-microm fiber experienced significant tip degradation after only 1,800 pulses. High irrigation rates were measured with the tapered fiber inserted through the working port of a flexible ureteroscope without hindering its deflection, mimicking that of a conventional 150 microm fiber. The short tapered distal fiber tip allows expansion of the laser beam, resulting in decreased fiber tip damage compared to conventional small-core fibers, without compromising fiber bending, stone vaporization efficiency, or irrigation rates.

Determining Coolant Flow Rate Distribution In The Fuel-Modified TRIGA Plate Reactor

NASA Astrophysics Data System (ADS)

Puji Hastuti, Endiah; Widodo, Surip; Darwis Isnaini, M.; Geni Rina, S.; Syaiful, B.

2018-02-01

TRIGA 2000 reactor in Bandung is planned to have the fuel element replaced, from cylindrical uranium and zirconium-hydride (U-ZrH) alloy to U3Si2-Al plate type of low enriched uranium of 19.75% with uranium density of 2.96 gU/cm3, while the reactor power is maintained at 2 MW. This change is planned to anticipate the discontinuity of TRIGA fuel element production. The selection of this plate-type fuel element is supported by the fact that such fuel type has been produced in Indonesia and used in MPR-30 safely since 2000. The core configuration of plate-type-fuelled TRIGA reactor requires coolant flow rate through each fuel element channel in order to meet its safety function. This paper is aimed to describe the results of coolant flow rate distribution in the TRIGA core that meets the safety function at normal operation condition, physical test, shutdown, and at initial event of loss of coolant flow due power supply interruption. The design analysis to determine coolant flow rate in this paper employs CAUDVAP and COOLODN computation code. The designed coolant flow rate that meets the safety criteria of departure from nucleate boiling ratio (DNBR), onset of flow instability ratio (OFIR), and ΔΤ onset of nucleate boiling (ONB), indicates that the minimum flow rate required to cool the plate-type fuelled TRIGA core at 2 MW is 80 kg/s. Therefore, it can be concluded that the operating limitation condition (OLC) for the minimum flow rate is 80 kg/s; the 72 kg/s is to cool the active core; while the minimum flow rate for coolant flow rate drop is limited to 68 kg/s with the coolant inlet temperature 35°C. This thermohydraulic design also provides cooling for 4 positions irradiation position (IP) utilization and 1 central irradiation position (CIP) with end fitting inner diameter (ID) of 10 mm and 20 mm, respectively.

Laboratory Equipment for Investigation of Coring Under Mars-like Conditions

NASA Astrophysics Data System (ADS)

Zacny, K.; Cooper, G.

2004-12-01

To develop a suitable drill bit and set of operating conditions for Mars sample coring applications, it is essential to make tests under conditions that match those of the mission. The goal of the laboratory test program was to determine the drilling performance of diamond-impregnated bits under simulated Martian conditions, particularly those of low pressure and low temperature in a carbon dioxide atmosphere. For this purpose, drilling tests were performed in a vacuum chamber kept at a pressure of 5 torr. Prior to drilling, a rock, soil or a clay sample was cooled down to minus 80 degrees Celsius (Zacny et al, 2004). Thus, all Martian conditions, except the low gravity were simulated in the controlled environment. Input drilling parameters of interest included the weight on bit and rotational speed. These two independent variables were controlled from a PC station. The dependent variables included the bit reaction torque, the depth of the bit inside the drilled hole and the temperatures at various positions inside the drilled sample, in the center of the core as it was being cut and at the bit itself. These were acquired every second by a data acquisition system. Additional information such as the rate of penetration and the drill power were calculated after the test was completed. The weight of the rock and the bit prior to and after the test were measured to aid in evaluating the bit performance. In addition, the water saturation of the rock was measured prior to the test. Finally, the bit was viewed under the Scanning Electron Microscope and the Stereo Optical Microscope. The extent of the bit wear and its salient features were captured photographically. The results revealed that drilling or coring under Martian conditions in a water saturated rock is different in many respects from drilling on Earth. This is mainly because the Martian atmospheric pressure is in the vicinity of the pressure at the triple point of water. Thus ice, heated by contact with the rotating bit, sublimed and released water vapor. The volumetric expansion of ice turning into a vapor was over 150 000 times. This continuously generated volume of gas effectively cleared the freeze-dried rock cuttings from the bottom of the hole. In addition, the subliming ice provided a powerful cooling effect that kept the bit cold and preserved the core in its original state. Keeping the rock core below freezing also reduced drastically the chances of cross contamination. To keep the bit cool in near vacuum conditions where convective cooling is poor, some intermittent stops would have to be made. Under virtually the same drilling conditions, coring under Martian low temperature and pressure conditions consumed only half the power while doubling the rate of penetration as compared to drilling under Earth atmospheric conditions. However, the rate of bit wear was much higher under Martian conditions (Zacny and Cooper, 2004) References Zacny, K. A., M. C. Quayle, and G. A. Cooper (2004), Laboratory drilling under Martian conditions yields unexpected results, J. Geophys. Res., 109, E07S16, doi:10.1029/2003JE002203. Zacny, K. A., and G. A. Cooper (2004), Investigation of diamond-impregnated drill bit wear while drilling under Earth and Mars conditions, J. Geophys. Res., 109, E07S10, doi:10.1029/2003JE002204. Acknowledgments The research supported by the NASA Astrobiology, Science and Technology Instrument Development (ASTID) program.

OECD 2-D Core Concrete Interaction (CCI) tests : CCI-2 test plan, Rev. 0 January 31, 2004.

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

Farmer, M. T.; Kilsdonk, D. J.; Lomperski, S.

The Melt Attack and Coolability Experiments (MACE) program addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. As a follow-on program to MACE, The Melt Coolability and Concrete Interaction Experiments (MCCI) project is conducting reactor material experiments and associated analysis to achieve the following objectives: (1)more » resolve the ex-vessel debris coolability issue through a program that focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests, and (2) address remaining uncertainties related to long-term two-dimensional molten core-concrete interactions under both wet and dry cavity conditions. Achievement of these two program objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs for future plants. In terms of satisfying these objectives, the Management Board (MB) approved the conduct of two long-term 2-D Core-Concrete Interaction (CCI) experiments designed to provide information in several areas, including: (i) lateral vs. axial power split during dry core-concrete interaction, (ii) integral debris coolability data following late phase flooding, and (iii) data regarding the nature and extent of the cooling transient following breach of the crust formed at the melt-water interface. The first of these two tests, CCI-1, was conducted on December 19, 2003. This test investigated the interaction of a fully oxidized 400 kg PWR core melt, initially containing 8 wt % calcined siliceous concrete, with a specially designed two-dimensional siliceous concrete test section with an initial cross-sectional area of 50 cm x 50 cm. The second of these two planned tests, CCI-2, will be conducted with a nearly identical test facility and experiment boundary conditions, but with a Limestone/Common Sand (LCS) concrete test section to investigate the effect of concrete type on the two-dimensional core-concrete interaction and debris cooling behavior. The objective of this report is to provide the overall test plan for CCI-2 to enable pretest calculations to be carried out. The report begins by providing a summary description of the CCI-2 test apparatus, followed by a description of the planned test operating procedure. Overall specifications for CCI-2 are provided in Table 1-1.« less

Determination of Heritage SSME Pogo Suppressor Resistance and Inertance from Waterflow Pulse Testing

NASA Technical Reports Server (NTRS)

McDougal, Chris; Eberhart, Chad; Lee, Erik

2016-01-01

Waterflow tests of a heritage Space Shuttle Main Engine pogo suppressor were performed to experimentally quantify the resistance and inertance provided by the suppressor. Measurements of dynamic pressure and flow rate in response to pulsing flow were made throughout the test loop. A unique system identification methodology combined all sensor measurements with a one-dimensional perturbational flow model of the complete water flow loop to spatially translate physical measurements to the device under test. Multiple techniques were then employed to extract the effective resistance and inertance for the pogo suppressor. Parameters such as steady flow rate, perturbational flow rate magnitude, and pulse frequency were investigated to assess their influence on the behavior of the pogo suppressor dynamic response. These results support validation of the RS-25 pogo suppressor performance for use on the Space Launch System Core Stage.

Cutaneous vascular and core temperature responses to sustained cold exposure in hypoxia.

PubMed

Simmons, Grant H; Barrett-O'Keefe, Zachary; Minson, Christopher T; Halliwill, John R

2011-10-01

We tested the effect of hypoxia on cutaneous vascular regulation and defense of core temperature during cold exposure. Twelve subjects had two microdialysis fibres placed in the ventral forearm and were immersed to the sternum in a bathtub on parallel study days (normoxia and poikilocapnic hypoxia with an arterial O(2) saturation of 80%). One fibre served as the control (1 mM propranolol) and the other received 5 mM yohimbine (plus 1 mM propranolol) to block adrenergic receptors. Skin blood flow was assessed at each site (laser Doppler flowmetry), divided by mean arterial pressure to calculate cutaneous vascular conductance (CVC), and scaled to baseline. Cold exposure was first induced by a progressive reduction in water temperature from 36 to 23°C over 30 min to assess cutaneous vascular regulation, then by clamping the water temperature at 10°C for 45 min to test defense of core temperature. During normoxia, cold stress reduced CVC in control (-44 ± 4%) and yohimbine sites (-13 ± 7%; both P < 0.05 versus precooling). Hypoxia caused vasodilatation prior to cooling but resulted in greater reductions in CVC in control (-67 ± 7%) and yohimbine sites (-35 ± 11%) during cooling (both P < 0.05 versus precooling; both P < 0.05 versus normoxia). Core cooling rate during the second phase of cold exposure was unaffected by hypoxia (-1.81 ± 0.23°C h(-1) in normoxia versus -1.97 ± 0.33°C h(-1) in hypoxia; P > 0.05). We conclude that hypoxia increases cutaneous (non-noradrenergic) vasoconstriction during prolonged cold exposure, while core cooling rate is not consistently affected.

ACHILLES: Heat Transfer in PWR Core During LOCA Reflood Phase

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

2013-11-01

1. NAME AND TITLE OF DATA LIBRARY ACHILLES -Heat Transfer in PWR Core During LOCA Reflood Phase. 2. NAME AND TITLE OF DATA RETRIEVAL PROGRAMS N/A 3. CONTRIBUTOR AEA Technology, Winfrith Technology Centre, Dorchester DT2 8DH United Kingdom through the OECD Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France. 4. DESCRIPTION OF TEST FACILITY The most important features of the Achilles rig were the shroud vessel, which contained the test section, and the downcomer. These may be thought of as representing the core barrel and the annular downcomer in the reactor pressure vessel. The test section comprises a cluster of 69more » rods in a square array within a circular shroud vessel. The rod diameter and pitch (9.5 mm and 12.6 mm) were typical of PWR dimensions. The internal diameter of the shroud vessel was 128 mm. Each rod was electrically heated over a length of 3.66 m, which is typical of the nuclear heated length in a PWR fuel rod, and each contained 6 internal thermocouples. These were arranged in one of 8 groupings which concentrated the thermocouples in different axial zones. The spacer grids were at prototypic PWR locations. Each grid had two thermocouples attached to its trailing edge at radial locations. The axial power profile along the rods was an 11 step approximation to a "chopped cosine". The shroud vessel had 5 heating zones whose power could be independently controlled. 5. DESCRIPTION OF TESTS The Achilles experiments investigated the heat transfer in the core of a Pressurized Water Reactor during the re-flood phase of a postulated large break loss of coolant accident. The results provided data to validate codes and to improve modeling. Different types of experiments were carried out which included single phase cooling, re-flood under low flow conditions, level swell and re-flood under high flow conditions. Three series of experiments were performed. The first and the third used the same test section but the second used another test section, similar in all respects except that it contained a partial blockage formed by attaching sleeves (or "balloons") to some of the rods. 6. SOURCE AND SCOPE OF DATA Phenomena Tested - Heat transfer in the core of a PWR during a re-flood phase of postulated large break LOCA. Test Designation - Achilles Rig. The programme includes the following types of experiments: - on an unballooned cluster: -- single phase air flow -- low pressure level swell -- low flooding rate re-flood -- high flooding rate re-flood - on a ballooned cluster containing 80% blockage formed by 16 balloon sleeves -- single phase air flow -- low flooding rate re-flood 7. DISCUSSION OF THE DATA RETRIEVAL PROGRAM N/A 8. DATA FORMAT AND COMPUTER Many Computers (M00019MNYCP00). 9. TYPICAL RUNNING TIME N/A 11. CONTENTS OF LIBRARY The ACHILLES package contains test data and associated data processing software as well as the documentation listed above. 12. DATE OF ABSTRACT November 2013. KEYWORDS: DATABASES, BENCHMARKS, HEAT TRANSFER, LOSS-OF-COLLANT ACCIDENT, PWR REACTORS, REFLOODING« less

65nm RadSafe™ Technology for RC64 and Advanced SOCs

NASA Astrophysics Data System (ADS)

Liran, Tuvia; Ginosar, Ran; Lange, Fredy; Mandler, Alberto; Aviely, Peleg; Meirov, Henri; Goldberg, Michael; Meister, Zeev; Oliel, Mickey

2015-09-01

The trend of scaling of microelectronic provides certain advantages for space components, as well as some challenges. It enables implementing highly integrated and high performance ASICs, reducing power, area and weight. Scaling also improves the immunity to TID and SEL in most cases, but increases soft error rate significantly. Ramon Chips adopted the 65nm technology for implementing RC64 [1,2], a 64 core DSP for space applications, and for making other future products. The 65nm process node is widely used, very mature, and supported by wide range of IP providers. Thus the need for full custom design of cores and IPs is minimized, and radiation hardening is achievable by mitigating the radiation effects on the available IPs, and developing proprietary IPs only for complementing the available IPs. The RadSafe_65TM technology includes hardened standard cells and I/O libraries, methods for mitigation of radiation effects in COTS IP cores (SRAM, PLL, SERDES, DDR2/3 interface) and adding unique cores for monitoring radiation effects and junction temperature. We had developed RADIC6, a technology development vehicle, for verification of all hard cores and verification of the methodologies and design flow required for RC64. RADIC6 includes the test structures for characterizing the IP cores for immunity to all radiation effects. This paper describes the main elements and IP cores of RadSafe_65TM, as well as the contents of RADIC6 test chip.

Students' Preferences for Lecturers' Personalities

ERIC Educational Resources Information Center

Tan, Sarah; Mansi, Angela; Furnham, Adrian

2018-01-01

The present study set out to examine students' preferences for lecturers' personality as a function of their classroom behaviour, core self-evaluations and self-rated character strengths. Various hypotheses were tested: first, students' Big Five traits would significantly predict corresponding personality preferences for lecturers (the matching…

A Criterion-Related Validation Study of the Army Core Leader Competency Model

DTIC Science & Technology

2007-04-01

2004). Transformational and transactional leadership: A meta-analytic test of their relative validity. Journal of Applied Psychology , 89, 755- 768...performance criteria in an attempt to adjust ratings for this influence. Leader survey materials were developed and pilot tested at Ft. Drum and Ft... psychological constructs in the behavioral science realm. Numerous theories, popular literature, websites, assessments, and competency models are

Constitutive Modeling of the Facesheet to Core Interface in Honeycomb Sandwich Panels Subject to Mode I Delamination

NASA Technical Reports Server (NTRS)

Hoewer, Daniel; Lerch, Bradley A.; Bednarcyk, Brett A.; Pineda, Evan Jorge; Reese, Stefanie; Simon, Jaan-Willem

2017-01-01

A new cohesive zone traction-separation law, which includes the effects of fiber bridging, has been developed, implemented with a finite element (FE) model, and applied to simulate the delamination between the facesheet and core of a composite honeycomb sandwich panel. The proposed traction-separation law includes a standard initial cohesive component, which accounts for the initial interfacial stiffness and energy release rate, along with a new component to account for the fiber bridging contribution to the delamination process. Single cantilever beam tests on aluminum honeycomb sandwich panels with carbon fiber reinforced polymer facesheets were used to characterize and evaluate the new formulation and its finite element implementation. These tests, designed to evaluate the mode I toughness of the facesheet to core interface, exhibited significant fiber bridging and large crack process zones, giving rise to a concave downward concave upward pre-peak shape in the load-displacement curve. Unlike standard cohesive formulations, the proposed formulation captures this observed shape, and its results have been shown to be in excellent quantitative agreement with experimental load-displacement and apparent critical energy release rate results, representative of a payload fairing structure, as well as local strain fields measured with digital image correlation.

GrowYourIC: an open access Python code to facilitate comparison between kinematic models of inner core evolution and seismic observations

NASA Astrophysics Data System (ADS)

Lasbleis, M.; Day, E. A.; Waszek, L.

2017-12-01

The complex nature of inner core structure has been well-established from seismic studies, with heterogeneities at various length scales, both radially and laterally. Despite this, no geodynamic model has successfully explained all of the observed seismic features. To facilitate comparisons between seismic observations and geodynamic models of inner core growth we have developed a new, open access Python tool - GrowYourIC - that allows users to compare models of inner core structure. The code allows users to simulate different evolution models of the inner core, with user-defined rates of inner core growth, translation and rotation. Once the user has "grown" an inner core with their preferred parameters they can then explore the effect of "their" inner core's evolution on the relative age and growth rate in different regions of the inner core. The code will convert these parameters into seismic properties using either built-in mineral physics models, or user-supplied ones that calculate these seismic properties with users' own preferred mineralogical models. The 3D model of isotropic inner core properties can then be used to calculate the predicted seismic travel time anomalies for a random, or user-specified, set of seismic ray paths through the inner core. A real dataset of inner core body-wave differential travel times is included for the purpose of comparing user-generated models of inner core growth to actual observed travel time anomalies in the top 100km of the inner core. Here, we explore some of the possibilities of our code. We investigate the effect of the limited illumination of the inner core by seismic waves on the robustness of kinematic model interpretation. We test the impact on seismic differential travel time observations of several kinematic models of inner core growth: fast lateral translation; slow differential growth; and inner core super-rotation. We find that a model of inner core evolution incorporating both differential growth and slow super-rotation is able to recreate some of the more intricate details of the seismic observations. Specifically we are able to "grow" an inner core that has an asymmetric shift in isotropic hemisphere boundaries with increasing depth in the inner core.

Magnetic core mesoporous silica nanoparticles doped with dacarbazine and labelled with 99mTc for early and differential detection of metastatic melanoma by single photon emission computed tomography.

PubMed

Portilho, Filipe Leal; Helal-Neto, Edward; Cabezas, Santiago Sánchez; Pinto, Suyene Rocha; Dos Santos, Sofia Nascimento; Pozzo, Lorena; Sancenón, Félix; Martínez-Máñez, Ramón; Santos-Oliveira, Ralph

2018-02-27

Cancer is responsible for more than 12% of all causes of death in the world, with an annual death rate of more than 7 million people. In this scenario melanoma is one of the most aggressive ones with serious limitation in early detection and therapy. In this direction we developed, characterized and tested in vivo a new drug delivery system based on magnetic core-mesoporous silica nanoparticle that has been doped with dacarbazine and labelled with technetium 99 m to be used as nano-imaging agent (nanoradiopharmaceutical) for early and differential diagnosis and melanoma by single photon emission computed tomography. The results demonstrated the ability of the magnetic core-mesoporous silica to be efficiently (>98%) doped with dacarbazine and also efficiently labelled with 99mTc (technetium 99 m) (>99%). The in vivo test, using inducted mice with melanoma, demonstrated the EPR effect of the magnetic core-mesoporous silica nanoparticles doped with dacarbazine and labelled with technetium 99 metastable when injected intratumorally and the possibility to be used as systemic injection too. In both cases, magnetic core-mesoporous silica nanoparticles doped with dacarbazine and labelled with technetium 99 metastable showed to be a reliable and efficient nano-imaging agent for melanoma.

A first step to compare geodynamical models and seismic observations of the inner core

NASA Astrophysics Data System (ADS)

Lasbleis, M.; Waszek, L.; Day, E. A.

2016-12-01

Seismic observations have revealed a complex inner core, with lateral and radial heterogeneities at all observable scales. The dominant feature is the east-west hemispherical dichotomy in seismic velocity and attenuation. Several geodynamical models have been proposed to explain the observed structure: convective instabilities, external forces, crystallisation processes or influence of outer core convection. However, interpreting such geodynamical models in terms of the seismic observations is difficult, and has been performed only for very specific models (Geballe 2013, Lincot 2014, 2016). Here, we propose a common framework to make such comparisons. We have developed a Python code that propagates seismic ray paths through kinematic geodynamical models for the inner core, computing a synthetic seismic data set that can be compared to seismic observations. Following the method of Geballe 2013, we start with the simple model of translation. For this, the seismic velocity is proposed to be function of the age or initial growth rate of the material (since there is no deformation included in our models); the assumption is reasonable when considering translation, growth and super rotation of the inner core. Using both artificial (random) seismic ray data sets and a real inner core data set (from Waszek et al. 2011), we compare these different models. Our goal is to determine the model which best matches the seismic observations. Preliminary results show that super rotation successfully creates an eastward shift in properties with depth, as has been observed seismically. Neither the growth rate of inner core material nor the relationship between crystal size and seismic velocity are well constrained. Consequently our method does not directly compute the seismic travel times. Instead, here we use age, growth rate and other parameters as proxies for the seismic properties, which represent a good first step to compare geodynamical and seismic observations.Ultimately we aim to release our codes to broader scientific community, allowing researchers from all disciplines to test their models of inner core growth against seismic observations or create a kinematic model for the evolution of the inner core which matches new geophysical observations.

Kinetics of heterotrophic biomass and storage mechanism in wetland cores measured by respirometry.

PubMed

Ortigara, A R C; Foladori, P; Andreottola, G

2011-01-01

Although oxygen uptake rate has been widely used in activated sludge for measuring kinetic and stoichiometric parameters or for wastewater characterization, its application in constructed wetlands (CWs) cores has been recently proposed. The aim of this research is to estimate the kinetic and stoichiometric parameters of the heterotrophic biomass in CW cores. Respirometric tests were carried out with pure carbonaceous substrate and real wastewater. Endogenous respiration was about 2 gO2 m(-3) h(-1) (per unit of bed volume), while the kinetic parameters obtained for COD oxidation were very high (maximum rate per unit of bed volume of 10.7-26.8 gCOD m(-3) h(-1)) which indicates high biodegradation potential in fully aerobic environment. Regarding to stoichiometric parameter, the maximum growth yield, Y(H), was 0.56-0.59 mgCOD/mgCOD, while the storage yield, Y(STO), was 0.75-0.77 mgCOD/mgCOD. The storage mechanism was observed in CW cores during COD oxidation, which leads to the transformation of the external soluble substrate in internal storage products, probably as response to intermittent loads applied in CW systems, transient concentrations of readily biodegradable substrate and alternance of feast/famine periods.

Nickel/silicon core/shell nanosheet arrays as electrode materials for lithium ion batteries

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

Huang, X.H., E-mail: drhuangxh@hotmail.com; Zhang, P.; Wu, J.B.

Highlights: • Ni nanosheet arrays is the core and Si layer is the shell. • Ni nanosheet arrays act as a three-dimensional current collector to support Si. • Ni nanosheet arrays can improve the conductivity and stability of the electrode. • Ni/Si nanosheet arrays exhibit excellent cyclic and rate performance. - Abstract: Ni/Si core/shell nanosheet arrays are proposed to enhance the electrochemical lithium-storage properties of silicon. The arrays are characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The arrays are micro-sized in height, which are constructed by interconnected Ni nanosheet as themore » core and Si coating layer as the shell. The electrochemical properties as anode materials of lithium ion batteries are investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge tests. The arrays can achieve high reversible capacity, good cycle stability and high rate capability. It is believed that the enhanced electrochemical performance is attributed to the electrode structure, because the interconnected Ni nanosheet can act as a three-dimensional current collector, and it has the ability of improving the electrode conductivity, enlarging the electrochemical reaction interface, and suppressing the electrode pulverization.« less

Constitutive Behavior Modelling of AA1100-O AT Large Strain and High Strain Rates

NASA Astrophysics Data System (ADS)

Testa, Gabriel; Iannitti, Gianluca; Ruggiero, Andrew; Gentile, Domenico; Bonora, Nicola

2017-06-01

Constitutive behavior of AA1100-O, provided as extruded bar, was investigated. Microscopic observation showed that the cross-section has a peculiar microstructure consisting in the inner core with a large grain size surrounded by an external annulus with finer grains. Low and high strain rates tensile tests were carried out at different temperature ranging from -190 ° C to 100 ° C. Constitutive behavior was modelled using a modified version of Rusinek & Klepaczko model. Parameters were calibrated on tensile test results. Tests and numerical simulations of symmetric Taylor (RoR) and dynamic tensile extrusion (DTE) tests at different impact velocities were carried out in order to validate the model under complex deformation paths.

An evaluation of the performance of concretes containing fly ash and ground slag in bridge decks.

DOT National Transportation Integrated Search

2006-01-01

Cores from 36 bridge decks were evaluated to assess the condition and quality of the concrete by petrographic methods and direct and indirect measures of the transport properties. Transport properties were measured by a rate of absorption test (ASTM ...

ELECTRON-CAPTURE AND β-DECAY RATES FOR sd-SHELL NUCLEI IN STELLAR ENVIRONMENTS RELEVANT TO HIGH-DENSITY O–NE–MG CORES

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

Suzuki, Toshio; Toki, Hiroshi; Nomoto, Ken’ichi, E-mail: suzuki@phys.chs.nihon-u.ac.jp

Electron-capture and β-decay rates for nuclear pairs in the sd-shell are evaluated at high densities and high temperatures relevant to the final evolution of electron-degenerate O–Ne–Mg cores of stars with initial masses of 8–10 M{sub ⊙}. Electron capture induces a rapid contraction of the electron-degenerate O–Ne–Mg core. The outcome of rapid contraction depends on the evolutionary changes in the central density and temperature, which are determined by the competing processes of contraction, cooling, and heating. The fate of the stars is determined by these competitions, whether they end up with electron-capture supernovae or Fe core-collapse supernovae. Since the competing processes aremore » induced by electron capture and β-decay, the accurate weak rates are crucially important. The rates are obtained for pairs with A = 20, 23, 24, 25, and 27 by shell-model calculations in the sd-shell with the USDB Hamiltonian. Effects of Coulomb corrections on the rates are evaluated. The rates for pairs with A = 23 and 25 are important for nuclear Urca processes that determine the cooling rate of the O–Ne–Mg core, while those for pairs with A = 20 and 24 are important for the core contraction and heat generation rates in the core. We provide these nuclear rates at stellar environments in tables with fine enough meshes at various densities and temperatures for studies of astrophysical processes sensitive to the rates. In particular, the accurate rate tables are crucially important for the final fates of not only O–Ne–Mg cores but also a wider range of stars, such as C–O cores of lower-mass stars.« less

New Progress on Radiocarbon Geochronology in Southern Lake Tanganyika (East Africa)

NASA Astrophysics Data System (ADS)

McGlue, M. M.; Soreghan, M. J.

2017-12-01

Our limnogeological research in Lake Tanganyika focuses on elucidating the patterns of sediment accumulation on deepwater horsts, outer platforms, and littoral environments in the lake's southern basin ( 6-8°S latitude). Here, we present new radiocarbon (14C) dates from high-quality surface sediment cores, in order to make comparisons with previously published age models, to address the presence and spatiotemporal variability of a reservoir effect, and to constrain sedimentation rates and facies at sites that may be important targets for future scientific drilling. Plant macrofossils are rare in deepwater sediment cores, so charcoal and bulk organic matter have been the primary materials used for dating. On the Kavala Island Ridge (KIR) horst, initial core descriptions revealed variations in laminae presence, thickness, and chemistry. Sediment cores from the KIR at 172m water depth consist of thickly laminated diatom oozes. Charcoal from the bases of these cores returned median ages of 2.1-2.2 cal ka, suggesting linear accumulation rates on the order of 0.51 mm/yr. By contrast, a core from 420 m water depth on the KIR exhibited very thin laminations and diatom layers were much less prominent. Charcoal at the base of this core produced a median age of 8.1 cal ka, suggesting a linear accumulation rate of 0.11 mm/yr. These initial results suggest that sedimentation rates may vary considerably over sublacustrine horst blocks. We will test this initial discovery with additional sedimentation rate information from the Kalya and Nitiri horsts. In addition, we report new 14C dates made on both dead and live-collected shells of the endemic gastropod Neothauma tanganyicense. These shells form vast accumulations along shallow-water platforms of the lake and form an important substrate for a number of other endemic species. The discovery of living snails in southern Lake Tanganyika may allow for the development of a species-specific reservoir correction. A limited N. tanganyicense shell 14C dataset from the lake's northern basin exhibits time averaged over the past 1600 cal yrs; results from this project will begin to address spatial variability in time averaging, and therefore improve our understanding of shell bed formation and the extent to which anthropogenic sedimentation is impacting shell bed persistence.

Microinjection of muscimol into the dorsomedial hypothalamus suppresses MDMA-evoked sympathetic and behavioral responses

PubMed Central

Rusyniak, Daniel E.; Zaretskaia, Maria V.; Zaretsky, Dmitry V.; DiMicco, Joseph A.

2008-01-01

When given systemically to rats and humans, the drug of abuse 3–4 methylenedioxymethamphetamine (ecstasy, MDMA) elicits hyperthermia, hyperactivity, tachycardia, and hypertension. Chemically stimulating the dorsomedial hypothalamus (DMH), a brain region known to be involved in thermoregulation and in stress responses, causes similar effects. We therefore tested the hypothesis that neuronal activity in the DMH plays a role in MDMA-evoked sympathetic and behavioral responses by microinjecting artificial CSF or muscimol, a neuronal inhibitor, into the DMH prior to intravenous infusion of saline or MDMA in conscious rats. Core temperature, heart rate, mean arterial pressure and locomotor activity were recorded by telemetry every minute for 120 minutes. In rats previously microinjected with CSF, MDMA elicited significant increases from baseline in core temperature (+1.3 ± 0.3°C), locomotion (+50 ± 6 counts/min), heart rate (+142 ± 16 beats/min), and mean arterial pressure (+26 ±3 mmHg). Microinjecting muscimol into the DMH prior to MDMA prevented increases in core temperature and locomotion and attenuated increases in heart rate and mean arterial pressure. These results indicate that neuronal activity in the DMH is necessary for the sympathetic and behavioral responses evoked by MDMA. PMID:18586013

The validity and reliability of a dynamic neuromuscular stabilization-heel sliding test for core stability.

PubMed

Cha, Young Joo; Lee, Jae Jin; Kim, Do Hyun; You, Joshua Sung H

2017-10-23

Core stabilization plays an important role in the regulation of postural stability. To overcome shortcomings associated with pain and severe core instability during conventional core stabilization tests, we recently developed the dynamic neuromuscular stabilization-based heel sliding (DNS-HS) test. The purpose of this study was to establish the criterion validity and test-retest reliability of the novel DNS-HS test. Twenty young adults with core instability completed both the bilateral straight leg lowering test (BSLLT) and DNS-HS test for the criterion validity study and repeated the DNS-HS test for the test-retest reliability study. Criterion validity was determined by comparing hip joint angle data that were obtained from BSLLT and DNS-HS measures. The test-retest reliability was determined by comparing hip joint angle data. Criterion validity was (ICC2,3) = 0.700 (p< 0.05), suggesting a good relationship between the two core stability measures. Test-retest reliability was (ICC3,3) = 0.953 (p< 0.05), indicating excellent consistency between the repeated DNS-HS measurements. Criterion validity data demonstrated a good relationship between the gold standard BSLLT and DNS-HS core stability measures. Test-retest reliability data suggests that DNS-HS core stability was a reliable test for core stability. Clinically, the DNS-HS test is useful to objectively quantify core instability and allow early detection and evaluation.

Interrelating the breakage and composition of mined and drill core coal

NASA Astrophysics Data System (ADS)

Wilson, Terril Edward

Particle size distribution of coal is important if the coal is to be beneficiated, or if a coal sales contract includes particle size specifications. An exploration bore core sample of coal ought to be reduced from its original cylindrical form to a particle size distribution and particle composition that reflects, insofar as possible, a process stream of raw coal it represents. Often, coal cores are reduced with a laboratory crushing machine, the product of which does not match the raw coal size distribution. This study proceeds from work in coal bore core reduction by Australian investigators. In this study, as differentiated from the Australian work, drop-shatter impact breakage followed by dry batch tumbling in steel cylinder rotated about its transverse axis are employed to characterize the core material in terms of first-order and zeroth-order breakage rate constants, which are indices of the propensity of the coal to degrade during excavation and handling. Initial drop-shatter and dry tumbling calibrations were done with synthetic cores composed of controlled low-strength concrete incorporating fly ash (as a partial substitute for Portland cement) in order to reduce material variables and conserve difficult-to-obtain coal cores. Cores of three different coalbeds--Illinois No. 6, Upper Freeport, and Pocahontas No. 5 were subjected to drop-shatter and dry batch tumbling tests to determine breakage response. First-order breakage, characterized by a first-order breakage index for each coal, occurred in the drop-shatter tests. First- and zeroth-order breakage occurred in dry batch tumbling; disappearance of coarse particles and creation of fine particles occurred in a systematic way that could be represented mathematically. Certain of the coal cores available for testing were dry and friable. Comparison of coal preparation plant feed with a crushed bore core and a bore core prepared by drop-shatter and tumbling (all from the same Illinois No.6 coal mining property) indicated that the size distribution and size fraction composition of the drop-shattered/tumbled core more closely resembled the plant feed than the crushed core. An attempt to determine breakage parameters (to allow use of selection and breakage functions and population balance models in the description of bore core size reduction) was initiated. Rank determination of the three coal types was done, indicating that higher rank associates with higher breakage propensity. The two step procedure of drop-shatter and dry batch tumbling simulates the first-order (volume breakage) and zeroth-order (abrasion of particle surfaces) that occur in excavation and handling operations, and is appropriate for drill core reduction prior to laboratory analysis.

An Improved SoC Test Scheduling Method Based on Simulated Annealing Algorithm

NASA Astrophysics Data System (ADS)

Zheng, Jingjing; Shen, Zhihang; Gao, Huaien; Chen, Bianna; Zheng, Weida; Xiong, Xiaoming

2017-02-01

In this paper, we propose an improved SoC test scheduling method based on simulated annealing algorithm (SA). It is our first to disorganize IP core assignment for each TAM to produce a new solution for SA, allocate TAM width for each TAM using greedy algorithm and calculate corresponding testing time. And accepting the core assignment according to the principle of simulated annealing algorithm and finally attain the optimum solution. Simultaneously, we run the test scheduling experiment with the international reference circuits provided by International Test Conference 2002(ITC’02) and the result shows that our algorithm is superior to the conventional integer linear programming algorithm (ILP), simulated annealing algorithm (SA) and genetic algorithm(GA). When TAM width reaches to 48,56 and 64, the testing time based on our algorithm is lesser than the classic methods and the optimization rates are 30.74%, 3.32%, 16.13% respectively. Moreover, the testing time based on our algorithm is very close to that of improved genetic algorithm (IGA), which is state-of-the-art at present.

Results of infiltration tests near Scott City, western Kansas

USGS Publications Warehouse

Gillespie, Joe B.; Hargadine, G.D.

1976-01-01

Several types of ring infiltrometers were used to determine infiltration rates in loessial soil near Scott City, Kansas. Test results were evaluated for consistency, and were compared with infiltration rates in the underlying loess and with hydraulic conductivities in the unsaturated zone.Average daily infiltration rates in the Richfield soil ranged from 3 to 5 feet or 0.9 to 1.5 m (metres) after 16 days using 22-inch or 560mm (millimetre) ring infiltrometers; 2.3 feet (0.7 m) after 68 days using a 10-inch (250-mm) ring infiltrometer; and from 1.3 to 2.2 feet (0.4 to 0.7 m) after 38 days using double-ring infiltrometers. By comparison, the average daily infiltration rate in the underlying Peoria Loess using a 10-inch (250-mm) ring infiltrometer was about 13 feet (4.0 m) after 7 days.Tests using the double-ring infiltrometer, a paraffin seal in the 22-inch (560-mm) infiltrometer, and the measurement of flow through concentric areas of the soil core indicated that leakage of water between the infiltrometer wall and the soil was not significant. Lateral movement of the wetting front extended radially 4.7 feet (1.4 m) from the infiltrometer wall.Laboratory tests of a soil core indicated that the lowest hydraulic conductivity was in the depth interval from 3.9 to 8.6 inches (99 to 218 mm). Soil in this interval, which coincides with the depth of cultivation, evidently limits the rate of infiltration.Air-permeability tests in the unsaturated deposits gave a hydraulic conductivity of 0.2 foot per day (0.1 m/day) for the depth interval from 57 to 75 feet (17.0 to 23.0 m) as compared to a hydraulic conductivity of 1.9 feet per day (0.6 m/day) for the depth interval from 0 to 5 feet (0 to 1.5 m). A perched water table probably would occur above this interval during prolonged infiltration.Infiltration rates determined from the different types of ring infiltrometers were not consistent, but the tests showed that substantial quantities of water could infiltrate the Richfield soil.

Simple Learned Weighted Sums of Inferior Temporal Neuronal Firing Rates Accurately Predict Human Core Object Recognition Performance

PubMed Central

Hong, Ha; Solomon, Ethan A.; DiCarlo, James J.

2015-01-01

To go beyond qualitative models of the biological substrate of object recognition, we ask: can a single ventral stream neuronal linking hypothesis quantitatively account for core object recognition performance over a broad range of tasks? We measured human performance in 64 object recognition tests using thousands of challenging images that explore shape similarity and identity preserving object variation. We then used multielectrode arrays to measure neuronal population responses to those same images in visual areas V4 and inferior temporal (IT) cortex of monkeys and simulated V1 population responses. We tested leading candidate linking hypotheses and control hypotheses, each postulating how ventral stream neuronal responses underlie object recognition behavior. Specifically, for each hypothesis, we computed the predicted performance on the 64 tests and compared it with the measured pattern of human performance. All tested hypotheses based on low- and mid-level visually evoked activity (pixels, V1, and V4) were very poor predictors of the human behavioral pattern. However, simple learned weighted sums of distributed average IT firing rates exactly predicted the behavioral pattern. More elaborate linking hypotheses relying on IT trial-by-trial correlational structure, finer IT temporal codes, or ones that strictly respect the known spatial substructures of IT (“face patches”) did not improve predictive power. Although these results do not reject those more elaborate hypotheses, they suggest a simple, sufficient quantitative model: each object recognition task is learned from the spatially distributed mean firing rates (100 ms) of ∼60,000 IT neurons and is executed as a simple weighted sum of those firing rates. SIGNIFICANCE STATEMENT We sought to go beyond qualitative models of visual object recognition and determine whether a single neuronal linking hypothesis can quantitatively account for core object recognition behavior. To achieve this, we designed a database of images for evaluating object recognition performance. We used multielectrode arrays to characterize hundreds of neurons in the visual ventral stream of nonhuman primates and measured the object recognition performance of >100 human observers. Remarkably, we found that simple learned weighted sums of firing rates of neurons in monkey inferior temporal (IT) cortex accurately predicted human performance. Although previous work led us to expect that IT would outperform V4, we were surprised by the quantitative precision with which simple IT-based linking hypotheses accounted for human behavior. PMID:26424887

43 CFR 3593.1 - Core or test hole cores, samples, cuttings.

Code of Federal Regulations, 2014 CFR

2014-10-01

.... (d) When drilling on lands with potential for encountering high pressure oil, gas or geothermal... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Core or test hole cores, samples, cuttings...) EXPLORATION AND MINING OPERATIONS Bore Holes and Samples § 3593.1 Core or test hole cores, samples, cuttings...

43 CFR 3593.1 - Core or test hole cores, samples, cuttings.

Code of Federal Regulations, 2012 CFR

2012-10-01

.... (d) When drilling on lands with potential for encountering high pressure oil, gas or geothermal... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Core or test hole cores, samples, cuttings...) EXPLORATION AND MINING OPERATIONS Bore Holes and Samples § 3593.1 Core or test hole cores, samples, cuttings...

43 CFR 3593.1 - Core or test hole cores, samples, cuttings.

Code of Federal Regulations, 2013 CFR

2013-10-01

.... (d) When drilling on lands with potential for encountering high pressure oil, gas or geothermal... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Core or test hole cores, samples, cuttings...) EXPLORATION AND MINING OPERATIONS Bore Holes and Samples § 3593.1 Core or test hole cores, samples, cuttings...

43 CFR 3593.1 - Core or test hole cores, samples, cuttings.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... (d) When drilling on lands with potential for encountering high pressure oil, gas or geothermal... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Core or test hole cores, samples, cuttings...) EXPLORATION AND MINING OPERATIONS Bore Holes and Samples § 3593.1 Core or test hole cores, samples, cuttings...

Intracardiac Vortex Dynamics by High-Frame-Rate Doppler Vortography-In Vivo Comparison With Vector Flow Mapping and 4-D Flow MRI.

PubMed

Faurie, Julia; Baudet, Mathilde; Assi, Kondo Claude; Auger, Dominique; Gilbert, Guillaume; Tournoux, Francois; Garcia, Damien

2017-02-01

Recent studies have suggested that intracardiac vortex flow imaging could be of clinical interest to early diagnose the diastolic heart function. Doppler vortography has been introduced as a simple color Doppler method to detect and quantify intraventricular vortices. This method is able to locate a vortex core based on the recognition of an antisymmetric pattern in the Doppler velocity field. Because the heart is a fast-moving organ, high frame rates are needed to decipher the whole blood vortex dynamics during diastole. In this paper, we adapted the vortography method to high-frame-rate echocardiography using circular waves. Time-resolved Doppler vortography was first validated in vitro in an ideal forced vortex. We observed a strong correlation between the core vorticity determined by high-frame-rate vortography and the ground-truth vorticity. Vortography was also tested in vivo in ten healthy volunteers using high-frame-rate duplex ultrasonography. The main vortex that forms during left ventricular filling was tracked during two-three successive cardiac cycles, and its core vorticity was determined at a sampling rate up to 80 duplex images per heartbeat. Three echocardiographic apical views were evaluated. Vortography-derived vorticities were compared with those returned by the 2-D vector flow mapping approach. Comparison with 4-D flow magnetic resonance imaging was also performed in four of the ten volunteers. Strong intermethod agreements were observed when determining the peak vorticity during early filling. It is concluded that high-frame-rate Doppler vortography can accurately investigate the diastolic vortex dynamics.

Flowing gas, non-nuclear experiments on the gas core reactor

NASA Technical Reports Server (NTRS)

Kunze, J. F.; Suckling, D. H.; Copper, C. G.

1972-01-01

Flow tests were conducted on models of the gas core (cavity) reactor. Variations in cavity wall and injection configurations were aimed at establishing flow patterns that give a maximum of the nuclear criticality eigenvalue. Correlation with the nuclear effect was made using multigroup diffusion theory normalized by previous benchmark critical experiments. Air was used to simulate the hydrogen propellant in the flow tests, and smoked air, argon, or freon to simulate the central nuclear fuel gas. All tests were run in the down-firing direction so that gravitational effects simulated the acceleration effect of a rocket. Results show that acceptable flow patterns with high volume fraction for the simulated nuclear fuel gas and high flow rate ratios of propellant to fuel can be obtained. Using a point injector for the fuel, good flow patterns are obtained by directing the outer gas at high velocity along the cavity wall, using louvered or oblique-angle-honeycomb injection schemes.

High resolution optically stimulated luminescence dating of a sediment core from the southwestern Sea of Okhotsk

NASA Astrophysics Data System (ADS)

Sugisaki, S.; Buylaert, J. P.; Murray, A. S.; Harada, N.; Kimoto, K.; Okazaki, Y.; Sakamoto, T.; Iijima, K.; Tsukamoto, S.; Miura, H.; Nogi, Y.

2012-05-01

Optically stimulated luminescence (OSL) dating is now widely accepted as a chronometer for terrestrial sediment. More recently, it has been suggested that OSL may also be useful in the dating of deep-sea marine sediments. In this paper, we test the usefulness of high resolution quartz OSL dating in application to a 19 m marine sediment core (MR0604-PC04A) taken from the southwestern Sea of Okhotsk, immediately to the north of Hokkaido, Japan. Fine-grained quartz (4 to 11μm) was chosen as the dosimeter, and a single-aliquot regenerative-dose protocol was used for the determination of equivalent dose (De), with stimulation by both infrared and blue light. The suitability of the measurement procedure was confirmed using dose recovery tests. A high resolution record (˜2 OSL ages/m) identified clear sedimentation rate changes down the core. The OSL ages are significantly dependent on the water content model chosen; two alternative interpretations are discussed, and the geologically preferred model identified. However, ages resulting from the observed (non-modeled) water content lie closest to the available radiocarbon ages (in the range back to 20 ka). Our OSL ages confirm the known high sedimentation rates in this locality, and for the first time demonstrate clear differences in sedimentation rate before, during and after deglaciation. Although the apparent accuracy of single sample ages is not always consistent with expectations, average ages are accurate, and our data show that OSL dating can be a powerful method for establishing high resolution marine chronologies.

Reservoir characterization of the Mt. Simon Sandstone, Illinois Basin, USA

USGS Publications Warehouse

Frailey, S.M.; Damico, J.; Leetaru, H.E.

2011-01-01

The integration of open hole well log analyses, core analyses and pressure transient analyses was used for reservoir characterization of the Mt. Simon sandstone. Characterization of the injection interval provides the basis for a geologic model to support the baseline MVA model, specify pressure design requirements of surface equipment, develop completion strategies, estimate injection rates, and project the CO2 plume distribution.The Cambrian-age Mt. Simon Sandstone overlies the Precambrian granite basement of the Illinois Basin. The Mt. Simon is relatively thick formation exceeding 800 meters in some areas of the Illinois Basin. In the deeper part of the basin where sequestration is likely to occur at depths exceeding 1000 m, horizontal core permeability ranges from less than 1 ?? 10-12 cm 2 to greater than 1 ?? 10-8 cm2. Well log and core porosity can be up to 30% in the basal Mt. Simon reservoir. For modeling purposes, reservoir characterization includes absolute horizontal and vertical permeability, effective porosity, net and gross thickness, and depth. For horizontal permeability, log porosity was correlated with core. The core porosity-permeability correlation was improved by using grain size as an indication of pore throat size. After numerous attempts to identify an appropriate log signature, the calculated cementation exponent from Archie's porosity and resistivity relationships was used to identify which porosity-permeability correlation to apply and a permeability log was made. Due to the relatively large thickness of the Mt. Simon, vertical permeability is an important attribute to understand the distribution of CO2 when the injection interval is in the lower part of the unit. Only core analyses and specifically designed pressure transient tests can yield vertical permeability. Many reservoir flow models show that 500-800 m from the injection well most of the CO2 migrates upward depending on the magnitude of the vertical permeability and CO2 injection rate (CO2 velocity). Assigning a specific value of vertical permeability to model cells is dependent on the vertical height of the model cell. Measured vertical permeability on core is scale dependent, such that lower vertical permeability is expected over longer core lengths compared to smaller lengths. Consequently, a series of vertical permeability tests were conducted on whole core varying in lengths of samples from 7 cm to 30 cm that showed vertical perm could change by an order of magnitude over a 30 cm height. For one well, the results from a series of pressure transient tests over a perforated interval much smaller than the gross thickness (<2%) confirmed the core-log based geologic model for vertical and horizontal permeability. A partial penetration model was used to estimate the horizontal and vertical permeability over a portion of the modeled area using series and parallel flow averaging techniques. ?? 2011 Published by Elsevier Ltd.

Reactor Simulator Testing Overview

NASA Technical Reports Server (NTRS)

Schoenfeld, Michael P.

2013-01-01

OBJECTIVE: Integrated testing of the TDU components TESTING SUMMARY: a) Verify the operation of the core simulator, the instrumentation and control system, and the ground support gas and vacuum test equipment. b) Thermal test heat regeneration design aspect of a cold trap purification filter. c) Pump performance test at pump voltages up to 150 V (targeted mass flow rate of 1.75 kg/s was not obtained in the RxSim at the originally constrained voltage of 120 V). TESTING HIGHLIGHTS: a) Gas and vacuum ground support test equipment performed effectively for NaK fill, loop pressurization, and NaK drain operations. b) Instrumentation and control system effectively controlled loop temperature and flow rates or pump voltage to targeted settings. c) Cold trap design was able to obtain the targeted cold temperature of 480 K. An outlet temperature of 636 K was obtained which was lower than the predicted 750 K but 156 K higher than the cold temperature indicating the design provided some heat regeneration. d) ALIP produce a maximum flow rate of 1.53 kg/s at 800 K when operated at 150 V and 53 Hz.

Strain-induced structural defects and their effects on the electrochemical performances of silicon core/germanium shell nanowire heterostructures

DOE PAGES

Lin, Yung-Chen; Kim, Dongheun; Li, Zhen; ...

2016-12-14

Here we report on strain-induced structural defect formation in core Si nanowire of Si/Ge core/shell nanowire heterostructure and influences of the structural defects on the electrochemical performances in lithium-ion battery anodes based on Si/Ge core/shell nanowire heterostructures. The induced structural defects consisting of stacking faults and dislocations in the core Si nanowire were observed for the first time. The generation of stacking faults in Si/Ge core/shell nanowire heterostructure is observed to prefer settling in either only Ge shell region or in both Ge shell and Si core regions and is associated with the increase of the shell volume fraction. Themore » relax of misfit strain in [112] oriented core/shell nanowire heterostructure leads to subsequent gliding of Shockley partial dislocations, preferentially forming the twins. The observation of cross-over defect formation is of great importance for the understanding of heteroepitaxy in radial heterostructures at nanoscale and building the three dimensional heterostructures for the various applications. In addition, the effect of the defect formation on nanomaterial’s functionality is investigated by electrochemical performance test. The Si/Ge core/shell nanowire heterostructures enhance the gravimetric capacity of lithium ion battery anodes under fast charging/discharging rates compared to Si nanowires. However, the induced structural defects hamper lithiation of the Si/Ge core/shell nanowire heterostructure.« less

Strain-induced structural defects and their effects on the electrochemical performances of silicon core/germanium shell nanowire heterostructures

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

Lin, Yung-Chen; Kim, Dongheun; Li, Zhen

Here we report on strain-induced structural defect formation in core Si nanowire of Si/Ge core/shell nanowire heterostructure and influences of the structural defects on the electrochemical performances in lithium-ion battery anodes based on Si/Ge core/shell nanowire heterostructures. The induced structural defects consisting of stacking faults and dislocations in the core Si nanowire were observed for the first time. The generation of stacking faults in Si/Ge core/shell nanowire heterostructure is observed to prefer settling in either only Ge shell region or in both Ge shell and Si core regions and is associated with the increase of the shell volume fraction. Themore » relax of misfit strain in [112] oriented core/shell nanowire heterostructure leads to subsequent gliding of Shockley partial dislocations, preferentially forming the twins. The observation of cross-over defect formation is of great importance for the understanding of heteroepitaxy in radial heterostructures at nanoscale and building the three dimensional heterostructures for the various applications. In addition, the effect of the defect formation on nanomaterial’s functionality is investigated by electrochemical performance test. The Si/Ge core/shell nanowire heterostructures enhance the gravimetric capacity of lithium ion battery anodes under fast charging/discharging rates compared to Si nanowires. However, the induced structural defects hamper lithiation of the Si/Ge core/shell nanowire heterostructure.« less

Qualification of CASMO5 / SIMULATE-3K against the SPERT-III E-core cold start-up experiments

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

Grandi, G.; Moberg, L.

SIMULATE-3K is a three-dimensional kinetic code applicable to LWR Reactivity Initiated Accidents. S3K has been used to calculate several international recognized benchmarks. However, the feedback models in the benchmark exercises are different from the feedback models that SIMULATE-3K uses for LWR reactors. For this reason, it is worth comparing the SIMULATE-3K capabilities for Reactivity Initiated Accidents against kinetic experiments. The Special Power Excursion Reactor Test III was a pressurized-water, nuclear-research facility constructed to analyze the reactor kinetic behavior under initial conditions similar to those of commercial LWRs. The SPERT III E-core resembles a PWR in terms of fuel type, moderator,more » coolant flow rate, and system pressure. The initial test conditions (power, core flow, system pressure, core inlet temperature) are representative of cold start-up, hot start-up, hot standby, and hot full power. The qualification of S3K against the SPERT III E-core measurements is an ongoing work at Studsvik. In this paper, the results for the 30 cold start-up tests are presented. The results show good agreement with the experiments for the reactivity initiated accident main parameters: peak power, energy release and compensated reactivity. Predicted and measured peak powers differ at most by 13%. Measured and predicted reactivity compensations at the time of the peak power differ less than 0.01 $. Predicted and measured energy release differ at most by 13%. All differences are within the experimental uncertainty. (authors)« less

Narrow Scale Flow and a Weak Field by the Top of Earth's Core: Evidence from Orsted, Magsat and Secular Variation

NASA Technical Reports Server (NTRS)

Voorhies, Coerte V.

2004-01-01

As Earth's main magnetic field weakens, our magnetic shield against the onslaught of the solar wind thins. And the field strength needed to fend off battering by solar coronal mass ejections is decreasing, just when the delicate complexity of modem, vulnerable, electro-technological systems is increasing at an unprecedented rate. Recently, a working group of distinguished scientist from across the nation has asked NASA's Solid Earth and Natural Hazards program a key question: What are the dynamics of Earth s magnetic field and its interactions with the Earth system? Paleomagnetic studies of crustal rocks magnetized in the geologic past reveal that polarity reversals have occurred many times during Earth s history. Networked super-computer simulations of core field and flow, including effects of gravitational, pressure, rotational Coriolis, magnetic and viscous forces, suggest how this might happen in detail. And space-based measurements of the real, time-varying magnetic field help constrain estimates of the speed and direction of fluid iron flowing near the top of the core and enable tests of some hypotheses about such flow. Now scientists at NASA s Goddard Space Flight Center have developed and applied methods to test the hypotheses of narrow scale flow and of a dynamically weak magnetic field near the top of Earth s core. Using two completely different methods, C. V. Voorhies has shown these hypotheses lead to specific theoretical forms for the "spectrum" of Earth s main magnetic field and the spectrum of its rate of change. Much as solar physicists use a prism to separate sunlight into its spectrum, from long wavelength red to short wavelength blue light, geophysicists use a digital prism, spherical harmonic analysis, to separate the measured geomagnetic field into its spectrum, from long to short wavelength fields. They do this for the rate of change of the field as well.

The effect of prior transfusion history on blood donor anti-hepatitis C virus antibody.

PubMed

Mazda, T; Nakata, K; Ota, K; Kaminuma, Y; Katayama, T

1993-01-01

In Japan, the major transfusion-associated disease is non-A, non-B hepatitis. We studied the relationship between transfusion history and blood donor antibodies to hepatitis C virus (HCV). The positive rate of antibodies to the HCV nonstructural protein (c100-3) depended on age and the time elapsed since transfusion. The anti-c100-3 ratio for subjects with transfusions made prior to 20 years ago was high. One quarter century ago, a change occurred in national blood policy from paid to non-paid voluntary donations. We also have studied the anti-HCV positive rate among donors with prior transfusion using a second generation HCV test kit which includes anti-HCV core antibody detection. The anti-HCV positive rate for the second generation test was higher than that for the anti-c100-3 test. Introduction of the second generation test is therefore more useful in screening than the anti-c100-3 test for blood programs.

A PILOT STUDY OF CORE STABILITY AND ATHLETIC PERFORMANCE: IS THERE A RELATIONSHIP?

PubMed Central

Sharrock, Chris; Cropper, Jarrod; Mostad, Joel; Johnson, Matt

2011-01-01

Study Design: Correlation study Objectives: To objectively evaluate the relationship between core stability and athletic performance measures in male and female collegiate athletes. Background: The relationship between core stability and athletic performance has yet to be quantified in the available literature. The current literature does not demonstrate whether or not core strength relates to functional performance. Questions remain regarding the most important components of core stability, the role of sport specificity, and the measurement of core stability in relation to athletic performance. Methods: A sample of 35 volunteer student athletes from Asbury College (NAIA Division II) provided informed consent. Participants performed a series of five tests: double leg lowering (core stability test), the forty yard dash, the T-test, vertical jump, and a medicine ball throw. Participants performed three trials of each test in a randomized order. Results: Correlations between the core stability test and each of the other four performance tests were determined using a General Linear Model. Medicine ball throw negatively correlated to the core stability test (r –0.389, p=0.023). Participants that performed better on the core stability test had a stronger negative correlation to the medicine ball throw (r =–0.527). Gender was the most strongly correlated variable to core strength, males with a mean measurement of double leg lowering of 47.43 degrees compared to females having a mean of 54.75 degrees. Conclusions: There appears to be a link between a core stability test and athletic performance tests; however, more research is needed to provide a definitive answer on the nature of this relationship. Ideally, specific performance tests will be able to better define and to examine relationships to core stability. Future studies should also seek to determine if there are specific sub-categories of core stability which are most important to allow for optimal training and performance for individual sports. PMID:21713228

NASA's Space Launch System: Progress Report

NASA Technical Reports Server (NTRS)

Cook, Jerry; Lyles, Garry

2017-01-01

NASA and its commercial industry team achieved significant progress in 2016 in manufacturing and testing of the Block 1 vehicle for the first launch of the Space Launch System (SLS). Test and flight article hardware for the liquid hydrogen fuel tank as well as the engine section for the core stage were completed at Michoud Assembly Facility (MAF) in New Orleans. Test stands neared completion at Marshall Space Flight Center for the propellant tanks, engine section, intertank and payload section. Stennis Space Center completed major structural renovations on the B2 test stand, where the core stage "green run" test program will be conducted. The SLS team completed a hotfire test series at Stennis to successfully demonstrate the ability of the RS-25 engine to operate under SLS environments and performance conditions. The team also test fired the second qualification five-segment solid rocket motor and cast the first six motor segments for the first SLS mission. The Interim Cryogenic Propulsion Stage (ICPS) test article was delivered to Marshall for structural tests, and work is nearly finished on the flight stage. Flight software testing completed at Marshall included power quality and command and data handling. In 2017, that work continues. SLS completed Preliminary Design Review (PDR) on the Exploration Upper Stage (EUS), a powerful, human-rated spacecraft that will propel explorers to cis-lunar space. In 2017, hardware will continue to be integrated at MAF for core stage structural test articles and the first two operational flights. RS-25 hotfire testing will continue to explore engine performance, as well as test flight-like software and four new Engine Controller Units (ECUs) for the first mission. Production of development components for a more affordable RS-25 design is underway. Core stage structural test articles have begun arriving at Marshall. While engineering challenges typical of a new development are possible, SLS is working toward launch readiness in late 2018. This paper will discuss these and other technical and programmatic successes and challenges over the past year and provide a preview of work ahead before first flight

The Social Networks and Paradoxes of the Opt-out Movement Amid the Common Core State Standards Implementation: The Case of New York

ERIC Educational Resources Information Center

Wang, Yinying

2017-01-01

Opting out of state standardized tests has recently become a movement--a series of grassroots, organized efforts to refuse to take high-stakes state standardized tests. In particular, the opt-out rates in the state of New York reached 20% in 2015 and 21% in 2016. This study aims to illustrate the social networks and examine the paradoxes that have…

Overview of experimental support for fission-product transport analyses at Oak Ridge National Laboratory

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

Wichner, R.P.

The program was designed to determine fission product and aerosol release rates from irradiated fuel under accident conditions, to identify the chemical forms of the released material, and to correlate the results with experimental and specimen conditions with the data from related experiments. These tests of PWR fuel were conducted and fuel specimen and test operating data are presented. The nature and rate of fission product vapor interaction with aerosols were studied. Aerosol deposition rates and transport in the reactor vessel during LWR core-melt accidents were studied. The Nuclear Safety Pilot Plant is dedicated to developing an expanded data basemore » on the behavior of aerosols generated during a severe accident.« less

Wireless, in-vessel neutron monitor for initial core-loading of advanced breeder reactors

NASA Technical Reports Server (NTRS)

Delorenzo, J. T.; Kennedy, E. J.; Blalock, T. V.; Rochelle, J. M.; Chiles, M. M.; Valentine, K. H.

1981-01-01

An experimental wireless, in-vessel neutron monitor was developed to measure the reactivity of an advanced breeder reactor as the core is loaded for the first time to preclude an accidental critically incident. The environment is liquid sodium at a temperature of approx. 220 C, with negligible gamma or neutron radiation. With ultrasonic transmission of neutron data, no fundamental limitation was observed after tests at 230 C for 2000 h. The neutron sensitivity was approx. 1 count/s-nv, and the potential data transmission rate was approx. 10,000 counts/s.

Photocatalytic hydrogen generation from water under visible light using core/shell nano-catalysts.

PubMed

Wang, X; Shih, K; Li, X Y

2010-01-01

A microemulsion technique was employed to synthesize nano-sized photocatalysts with a core (CdS)/shell (ZnS) structure. The primary particles of the photocatalysts were around 10 nm, and the mean size of the catalyst clusters in water was about 100 nm. The band gaps of the catalysts ranged from 2.25 to 2.46 eV. The experiments of photocatalytic H(2) generation showed that the catalysts (CdS)(x)/(ZnS)(1-x) with x ranging from 0.1 to 1 were able to produce hydrogen from water photolysis under visible light. The catalyst with x=0.9 had the highest rate of hydrogen production. The catalyst loading density also influenced the photo-hydrogen production rate, and the best catalyst concentration in water was 1 g L(-1). The stability of the nano-catalysts in terms of size, morphology and activity was satisfactory during an extended test period for a specific hydrogen production rate of 2.38 mmol g(-1) L(-1) h(-1) and a quantum yield of 16.1% under visible light (165 W Xe lamp, lambda>420 nm). The results demonstrate that the (CdS)/(ZnS) core/shell nano-particles are a novel photo-catalyst for renewable hydrogen generation from water under visible light. This is attributable to the large band-gap ZnS shell that separates the electron/hole pairs generated by the CdS core and hence reduces their recombinations.

[The relevance of core muscles in ice hockey players: a feasibility study].

PubMed

Rogan, S; Blasimann, A; Nyffenegger, D; Zimmerli, N; Radlinger, L

2013-12-01

Good core strength is seen as a condition for high performance in sports. In general, especially maximum voluntary contraction (MVC) and strength endurance (SE) measurements of the core muscles are used. In addition, a few studies can be found that examine the core muscles in terms of MVC, rate of force development (RFD) and SE. Primary aims of this feasibility study were to investigate the feasibility regarding recruiting process, compliance and safety of the testing conditions and raise the force capabilities MVC, RFD and SE of the core muscles in amateur ice hockey players. Secondarily, tendencies of correlations between muscle activity and either shot speed and sprint time shall be examined. In this feasibility study the recruitment process has been approved by 29 ice hockey players, their adherence to the study measurements of trunk muscles, and safety of the measurements was evaluated. To determine the MVC, RFD and SE for the ventral, lateral and dorsal core muscles a dynamic force measurement was performed. To determine the correlation between core muscles and shot speed and 40-m sprint, respectively, the rank correlation coefficient (rho) from Spearman was used. The recruited number of eight field players and one goal-keeper was not very high. The compliance with 100 % was excellent. The players reported no adverse symptoms or injuries after the measurements. The results show median values for the ventral core muscles for MVC with 46.5 kg for RFD with 2.23 m/s2 and 96 s for the SE. For lateral core muscle median values of the lateral core muscles for MVC with 71.10 kg, RFD with 2.59 m/s2 and for SE over 66 s were determined. The dorsal core muscles shows values for MVC 69.7 kg, for RFD 3.39 m/s2 and for SE of 75 s. High correlations between MVC of the ventral core muscles (rho = -0.721, p = 0.021), and between the SE of the ventral core muscles (rho = 0.787, p = 0.012), and the shot velocity rate were determined. Another high correlation between SE of the ventral core muscles and sprint over 40 m (rho = 0.717, p = 0.030) could be demonstrated. This feasibility study has shown that the implementation of the selected design is adapted for future studies. Further studies are needed to better understand the relationship between the velocity rate and the MVC, and the SE respectively, as well as between the sprint and the SE. © Georg Thieme Verlag KG Stuttgart · New York.

Effects of heat acclimation on time perception.

PubMed

Tamm, Maria; Jakobson, Ainika; Havik, Merle; Timpmann, Saima; Burk, Andres; Ööpik, Vahur; Allik, Jüri; Kreegipuu, Kairi

2015-03-01

Cognitive performance is impaired during prolonged exercise in hot environment compared to temperate conditions. These effects are related to both peripheral markers of heats stress and alterations in CNS functioning. Repeated-exposure to heat stress results in physiological adaptations, and therefore improvement in exercise capacity and cognitive functioning are observed. The objective of the current study was to clarify the factors contributing to time perception under heat stress and examine the effect of heat acclimation. 20 young healthy male subjects completed three exercise tests on a treadmill: H1 (at 60% VO(2)peak until exhaustion at 42°C), N (at 22°C; duration equal to H1) and H2 (walk until exhaustion at 42°C) following a 10-day heat acclimation program. Core temperature (T(C)) and heart rate (HR), ratings of perceived fatigue and exertion were obtained continuously during the exercise, and blood samples of hormones were taken before, during and after the exercise test for estimating the prolactin, growth hormone and cortisol response to acute exercise-heat stress. Interval production task was performed before, during and after the exercise test. Lower rate of rise in core temperature, heart rate, hormone response and subjective ratings indicated that the subjects had successfully acclimated. Before heat acclimation, significant distortions in produced intervals occurred after 60 minutes of exercise relative to pre-trial coefficients, indicating speeded temporal processing. However, this effect was absent after in acclimated subjects. Blood prolactin concentration predicted temporal performance in both conditions. Heat acclimation slows down the increase in physiological measures, and improvement in temporal processing is also evident. The results are explained within the internal clock model in terms of the pacemaker-accumulator functioning. Copyright © 2014 Elsevier B.V. All rights reserved.

Coding for parallel execution of hardware-in-the-loop millimeter-wave scene generation models on multicore SIMD processor architectures

NASA Astrophysics Data System (ADS)

Olson, Richard F.

2013-05-01

Rendering of point scatterer based radar scenes for millimeter wave (mmW) seeker tests in real-time hardware-in-the-loop (HWIL) scene generation requires efficient algorithms and vector-friendly computer architectures for complex signal synthesis. New processor technology from Intel implements an extended 256-bit vector SIMD instruction set (AVX, AVX2) in a multi-core CPU design providing peak execution rates of hundreds of GigaFLOPS (GFLOPS) on one chip. Real world mmW scene generation code can approach peak SIMD execution rates only after careful algorithm and source code design. An effective software design will maintain high computing intensity emphasizing register-to-register SIMD arithmetic operations over data movement between CPU caches or off-chip memories. Engineers at the U.S. Army Aviation and Missile Research, Development and Engineering Center (AMRDEC) applied two basic parallel coding methods to assess new 256-bit SIMD multi-core architectures for mmW scene generation in HWIL. These include use of POSIX threads built on vector library functions and more portable, highlevel parallel code based on compiler technology (e.g. OpenMP pragmas and SIMD autovectorization). Since CPU technology is rapidly advancing toward high processor core counts and TeraFLOPS peak SIMD execution rates, it is imperative that coding methods be identified which produce efficient and maintainable parallel code. This paper describes the algorithms used in point scatterer target model rendering, the parallelization of those algorithms, and the execution performance achieved on an AVX multi-core machine using the two basic parallel coding methods. The paper concludes with estimates for scale-up performance on upcoming multi-core technology.

Posttest calculations of bundle quench test CORA-13 with ATHLET-CD

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

Bestele, J.; Trambauer, K.; Schubert, J.D.

Gesellschaft fuer Anlagen- und Reaktorsicherheit is developing, in cooperation with the Institut fuer Kernenergetik und Energiesysteme, Stuttgart, the system code Analysis of Thermalhydraulics of Leaks and Transients with Core Degradation (ATHLET-CD). The code consists of detailed models of the thermal hydraulics of the reactor coolant system. This thermo-fluid dynamics module is coupled with modules describing the early phase of the core degradation, like cladding deformation, oxidation and melt relocation, and the release and transport of fission products. The assessment of the code is being done by the analysis of separate effect tests, integral tests, and plant events. The code willmore » be applied to the verification of severe accident management procedures. The out-of-pile test CORA-13 was conducted by Forschungszentrum Karlsruhe in their CORA test facility. The test consisted of two phases, a heatup phase and a quench phase. At the beginning of the quench phase, a sharp peak in the hydrogen generation rate was observed. Both phases of the test have been calculated with the system code ATHLET-CD. Special efforts have been made to simulate the heat losses and the flow distribution in the test facility and the thermal hydraulics during the quench phase. In addition to previous calculations, the material relocation and the quench phase have been modeled. The temperature increase during the heatup phase, the starting time of the temperature escalation, and the maximum temperatures have been calculated correctly. At the beginning of the quench phase, an increased hydrogen generation rate has been calculated as measured in the experiment.« less

77 FR 36014 - Initial Test Program of Emergency Core Cooling Systems for Boiling-Water Reactors

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-15

... NUCLEAR REGULATORY COMMISSION [NRC-2012-0134] Initial Test Program of Emergency Core Cooling... for public comment draft regulatory guide (DG), DG-1277, ``Initial Test Program of Emergency Core... acceptable to implement with regard to initial testing features of emergency core cooling systems (ECCSs) for...

The Effect of High School Shootings on Schools and Student Performance

ERIC Educational Resources Information Center

Beland, Louis-Philippe; Kim, Dongwoo

2016-01-01

We analyze how fatal shootings in high schools affect schools and students using data from shooting databases, school report cards, and the Common Core of Data. We examine schools' test scores, enrollment, number of teachers, graduation, attendance, and suspension rates at schools that experienced a shooting, employing a difference-in-differences…

Static test-stand performance of the YF-102 turbofan engine with several exhaust configurations for the Quiet Short-Haul Research Aircraft (QSRA)

NASA Technical Reports Server (NTRS)

Mcardle, J. G.; Homyak, L.; Moore, A. S.

1979-01-01

The performance of a YF-102 turbofan engine was measured in an outdoor test stand with a bellmouth inlet and seven exhaust-system configurations. The configurations consisted of three separate-flow systems of various fan and core nozzle sizes and four confluent-flow systems of various nozzle sizes and shapes. A computer program provided good estimates of the engine performance and of thrust at maximum rating for each exhaust configuration. The internal performance of two different-shaped core nozzles for confluent-flow configurations was determined to be satisfactory. Pressure and temperature surveys were made with a traversing probe in the exhaust-nozzle flow for some confluent-flow configurations. The survey data at the mixing plane, plus the measured flow rates, were used to calculate the static-pressure variation along the exhaust nozzle length. The computed pressures compared well with experimental wall static-pressure data. External-flow surveys were made, for some confluent-flow configurations, with a large fixed rake at various locations in the exhaust plume.

Bilayer tablets of Paliperidone for Extended release osmotic drug delivery

NASA Astrophysics Data System (ADS)

Chowdary, K. Sunil; Napoleon, A. A.

2017-11-01

The purpose of this study is to develop and optimize the formulation of paliperidone bilayer tablet core and coating which should meet in vitro performance of trilayered Innovator sample Invega. Optimization of core formulations prepared by different ratio of polyox grades and optimization of coating of (i) sub-coating build-up with hydroxy ethyl cellulose (HEC) and (ii).enteric coating build-up with cellulose acetate (CA). Some important influence factors such as different core tablet compositions and different coating solution ingredients involved in the formulation procedure were investigated. The optimization of formulation and process was conducted by comparing different in vitro release behaviours of Paliperidone. In vitro dissolution studies of Innovator sample (Invega) with formulations of different release rate which ever close release pattern during the whole 24 h test is finalized.

OECD MCCI 2-D Core Concrete Interaction (CCI) tests : CCI-2 test data report-thermalhydraulic results, Rev. 0 October 15, 2004.

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

Farmer, M. T.; Lomperski, S.; Kilsdonk, D. J.

The Melt Attack and Coolability Experiments (MACE) program addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. As a follow-on program to MACE, The Melt Coolability and Concrete Interaction Experiments (MCCI) project is conducting reactor material experiments and associated analysis to achieve the following objectives: (1)more » resolve the ex-vessel debris coolability issue through a program that focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests, and (2) address remaining uncertainties related to long-term two-dimensional molten core-concrete interactions under both wet and dry cavity conditions. Achievement of these two program objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs for future plants. In terms of satisfying these objectives, the Management Board (MB) approved the conduct of two long-term 2-D Core-Concrete Interaction (CCI) experiments designed to provide information in several areas, including: (i) lateral vs. axial power split during dry core-concrete interaction, (ii) integral debris coolability data following late phase flooding, and (iii) data regarding the nature and extent of the cooling transient following breach of the crust formed at the melt-water interface. This data report provides thermal hydraulic test results from the CCI-2 experiment, which was conducted on August 24, 2004. Test specifications for CCI-2 are provided in Table 1-1. This experiment investigated the interaction of a fully oxidized 400 kg PWR core melt, initially containing 8 wt % Limestone/Common Sand (LCS) concrete, with a specially designed two-dimensional LCS concrete test section with an initial cross-sectional area of 50 cm x 50 cm. The report begins by providing a summary description of the CCI-2 test apparatus and operating procedures, followed by presentation of the thermal-hydraulic results. Detailed posttest debris examination results will be provided in a subsequent publication. Observations drawn within this report regarding the overall cavity erosion behavior may be subject to revision once the posttest examinations are completed, since these examinations will fully reveal the final cavity shape.« less

Shock initiated reactions of reactive multi-phase blast explosives

NASA Astrophysics Data System (ADS)

Wilson, Dennis; Granier, John; Johnson, Richard; Littrell, Donald

2017-01-01

This paper describes a new class of non-ideal explosive compositions made of perfluoropolyether (PFPE), nanoaluminum, and a micron-size, high mass density, reactive metal. Unlike high explosives, these compositions release energy via a fast self-oxidized combustion wave rather than a true self-sustaining detonation. Their reaction rates are shock dependent and they can be overdriven to change their energy release rate. These compositions are fuel rich and have an extended aerobic energy release phase. The term "reactive multiphase blast" refers to the post-dispersion blast behavior: multiphase in that there are a gas phase that imparts pressure and a solid (particulate) phase that imparts energy and momentum [1]; and reactive in that the hot metal particles react with atmospheric oxygen and the explosive gas products to give an extended pressure pulse. Tantalum-based RMBX formulations were tested in two spherical core-shell configurations - an RMBX shell exploded by a high explosive core, and an RMBX core imploded by a high explosive shell. The fireball and blast characteristics were compared to a C-4 baseline charge.

Ten-core versus 16-core transrectal ultrasonography guided prostate biopsy for detection of prostatic carcinoma: a prospective comparative study in Indian population

PubMed Central

Prakash, V. Surya; Mohan, G. Chandra; Krishnaiah, S. Venkata; Vijaykumar, V.; Babu, G. Ramesh; Reddy, G. Vijaya Bhaskar; Mahaboob, V. S.

2013-01-01

Purpose: To compare the cancer detection rate in patients with raised serum prostate-specific antigen (PSA) or abnormal digital rectal examination (DRE) results between the 10-core and the 16-core biopsy techniques in an Indian population. Methods: Between November 2010 and November 2012, 95 men aged >50 years who presented to the Urology Department with lower urinary tract symptoms, elevated serum PSA, and/or abnormal DRE findings underwent transrectal ultrasonography (TRUS)-guided prostate biopsy. A total of 53 patients underwent 10-core biopsy and 42 patients underwent 16-core biopsy. Results: Of the 53 men in the 10-core group, 8 had cancer, whereas in the 16-core biopsy group, 23 of 42 men had cancer. Detection of prostate cancer was significantly higher in patients who underwent 16-core biopsy than in those who underwent 10-core biopsy (P<0.001). Among the 95 men, 44 men had abnormal DRE findings (46.3%), of whom 23 showed cancer (52.27%). Of 51 men with normal DRE findings and elevated PSA, 8 men had malignancy with a cancer detection rate of 15.68%. Among 20 men with PSA between 4.1 and 10 ng/mL, 2 (10%) had cancer. In 31 men with PSA between 10.1 and 20 ng/mL, 3 cancers (9.67%) were detected, and in 44 men with PSA >20 ng/mL, 26 cancers were detected (59.09%). Conclusions: The cancer detection rate with 16-core TRUS-guided biopsy is significantly higher than that with 10-core biopsy (54.76% vs. 15.09%, P<0.001). In patients with both normal and abnormal DRE findings, 16-core biopsy has a better detection rate than the 10-core biopsy protocol. With increasing PSA, there is a high rate of detection of prostate cancer in both 10-core and 16-core biopsy patients. PMID:24392441

Ten-core versus 16-core transrectal ultrasonography guided prostate biopsy for detection of prostatic carcinoma: a prospective comparative study in Indian population.

PubMed

Prakash, V Surya; Mohan, G Chandra; Krishnaiah, S Venkata; Vijaykumar, V; Babu, G Ramesh; Reddy, G Vijaya Bhaskar; Mahaboob, V S

2013-01-01

To compare the cancer detection rate in patients with raised serum prostate-specific antigen (PSA) or abnormal digital rectal examination (DRE) results between the 10-core and the 16-core biopsy techniques in an Indian population. Between November 2010 and November 2012, 95 men aged >50 years who presented to the Urology Department with lower urinary tract symptoms, elevated serum PSA, and/or abnormal DRE findings underwent transrectal ultrasonography (TRUS)-guided prostate biopsy. A total of 53 patients underwent 10-core biopsy and 42 patients underwent 16-core biopsy. Of the 53 men in the 10-core group, 8 had cancer, whereas in the 16-core biopsy group, 23 of 42 men had cancer. Detection of prostate cancer was significantly higher in patients who underwent 16-core biopsy than in those who underwent 10-core biopsy (P<0.001). Among the 95 men, 44 men had abnormal DRE findings (46.3%), of whom 23 showed cancer (52.27%). Of 51 men with normal DRE findings and elevated PSA, 8 men had malignancy with a cancer detection rate of 15.68%. Among 20 men with PSA between 4.1 and 10 ng/mL, 2 (10%) had cancer. In 31 men with PSA between 10.1 and 20 ng/mL, 3 cancers (9.67%) were detected, and in 44 men with PSA >20 ng/mL, 26 cancers were detected (59.09%). The cancer detection rate with 16-core TRUS-guided biopsy is significantly higher than that with 10-core biopsy (54.76% vs. 15.09%, P<0.001). In patients with both normal and abnormal DRE findings, 16-core biopsy has a better detection rate than the 10-core biopsy protocol. With increasing PSA, there is a high rate of detection of prostate cancer in both 10-core and 16-core biopsy patients.

The efficacy of a supervised and a home-based core strengthening programme in adults with poor core stability: a three-arm randomised controlled trial.

PubMed

Chuter, V H; de Jonge, X A K Janse; Thompson, B M; Callister, R

2015-03-01

Poor core stability is linked to a range of musculoskeletal pathologies and core-strengthening programmes are widely used as treatment. Treatment outcomes, however, are highly variable, which may be related to the method of delivery of core strengthening programmes. We investigated the effect of identical 8 week core strengthening programmes delivered as either supervised or home-based on measures of core stability. Participants with poor core stability were randomised into three groups: supervised (n=26), home-based (n=26) or control (n=26). Primary outcomes were the Sahrmann test and the Star Excursion Balance Test (SEBT) for dynamic core stability and three endurance tests (side-bridge, flexor and Sorensen) for static core stability. The exercise programme was devised and supervised by an exercise physiologist. Analysis of covariance on the change from baseline over the 8 weeks showed that the supervised group performed significantly better on all core stability measures than both the home-based and control group. The home-based group produced significant improvements compared to the control group in all static core stability tests, but not in most of the dynamic core stability tests (Sahrmann test and two out of three directions of the SEBT). Our results support the use of a supervised core-strengthening programme over a home-based programme to maximise improvements in core stability, especially in its dynamic aspects. Based on our findings in healthy individuals with low core stability, further research is recommended on potential therapeutic benefits of supervised core-strengthening programmes for pathologies associated with low core stability. ACTRN12613000233729. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Relationship between scapular muscle and core endurance in healthy subjects.

PubMed

Hazar Kanik, Zeynep; Pala, Omer Osman; Gunaydin, Gurkan; Sozlu, Ugur; Alkan, Zeynep Beyza; Basar, Selda; Citaker, Seyit

2017-01-01

Scapular muscle endurance and core endurance reportedly influence shoulder injury risk. The exact relationship between scapular muscle endurance and core endurance, and how they impact one another in the healthy subjects remain unclear. To investigate the relationship between scapular muscle endurance and core endurance in healthy subjects. Fifty healthy volunteers (23 males, 27 females; mean age 20.42 ± 1.04 years) were participated in this study. Endurance of the serratus anterior and trapezius muscles was assessed using the scapular muscle endurance test. Sorensen test (endurance of trunk extensor muscles), trunk flexor endurance test, and side bridge test (endurance of lateral core muscles) were conducted to assess the core endurance. Pearson's product moment correlations examined relationships between scapular muscle endurance and each of the core endurance tests scores. Scapular muscle endurance test scores showed a positive correlation with the side bridge test scores (r = 0.414; p = 0.003). No significant correlation was found between scapular muscle endurance test scores and the other core endurance tests scores (p > 0.05). There appears to be a link between the scapular muscle endurance and lateral core muscles in healthy subjects; however, more research is needed to provide a definitive answer on the nature of this relationship. Further studies involving patients with shoulder pathology are warranted.

An electromagnetic microvalve for pneumatic control of microfluidic systems.

PubMed

Liu, Xuling; Li, Songjing

2014-10-01

An electromagnetic microvalve for pneumatic control of microfluidic devices has been designed, fabricated, and tested. The microvalve is composed of two parts: a miniature electromagnetic actuator and a valve body. The electromagnetic actuator consists mainly of a thin polydimethylsiloxane (PDMS)-based elastomer, which acts as the valve diaphragm. The diaphragm, used as a solid hydraulic medium, converts the large contact area of a valve core into a small contact area of valve head while maintaining a large stroking force. This microvalve remains closed because of a compressed mechanical spring force generated by the actuator. On the other hand, when a voltage is applied, the valve core moves up, relaxing the thin PDMS membrane, opening the microvalve. The fast open response (~17 ms) of the valve was achieved with a leak rate as low as 0.026 sccm at 200 KPa (N2) pressure. We tested the pertinent dynamic parameters such as flow rate in on/off mode, flow rate of duty cycles, and actuated frequencies in pulse width modulation (PWM) mode. Our method provides a simple, cheap, and small microvalve that avoids the bulky and expensive external pressure control solenoid manifold. This allows it to be easily integrated into portable and disposable devices. © 2014 Society for Laboratory Automation and Screening.

Circulation system for flowing uranium hexafluoride cavity reactor experiments

NASA Technical Reports Server (NTRS)

Jaminet, J. F.; Kendall, J. S.

1976-01-01

Research related to determining the feasibility of producing continuous power from fissile fuel in the gaseous state is presented. The development of three laboratory-scale flow systems for handling gaseous UF6 at temperatures up to 500 K, pressure up to approximately 40 atm, and continuous flow rates up to approximately 50g/s is presented. A UF6 handling system fabricated for static critical tests currently being conducted is described. The system was designed to supply UF6 to a double-walled aluminum core canister assembly at temperatures between 300 K and 400 K and pressure up to 4 atm. A second UF6 handling system designed to provide a circulating flow of up to 50g/s of gaseous UF6 in a closed-loop through a double-walled aluminum core canister with controlled temperature and pressure is described. Data from flow tests using UF6 and UF6/He mixtures with this system at flow rates up to approximately 12g/s and pressure up to 4 atm are presented. A third UF6 handling system fabricated to provide a continuous flow of UF6 at flow rates up to 5g/s and at pressures up to 40 atm for use in rf-heated, uranium plasma confinement experiments is described.

Conceptual model for transport processes in the Culebra Dolomite Member, Rustler Formation

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

Holt, R.M.

1997-08-01

The Culebra Dolomite Member of the Rustler Formation represents a possible pathway for contaminants from the Waste Isolation Pilot Plant underground repository to the accessible environment. The geologic character of the Culebra is consistent with a double-porosity, multiple-rate model for transport in which the medium is conceptualized as consisting of advective porosity, where solutes are carried by the groundwater flow, and fracture-bounded zones of diffusive porosity, where solutes move through slow advection or diffusion. As the advective travel length or travel time increases, the nature of transport within a double-porosity medium changes. This behavior is important for chemical sorption, becausemore » the specific surface area per unit mass of the diffusive porosity is much greater than in the advective porosity. Culebra transport experiments conducted at two different length scales show behavior consistent with a multiple-rate, double-porosity conceptual model for Culebra transport. Tracer tests conducted on intact core samples from the Culebra show no evidence of significant diffusion, suggesting that at the core scale the Culebra can be modeled as a single-porosity medium where only the advective porosity participates in transport. Field tracer tests conducted in the Culebra show strong double-porosity behavior that is best explained using a multiple-rate model.« less

Detecting the position of the moving-iron solenoid by non-displacement sensor based on parameter identification of flux linkage characteristics

NASA Astrophysics Data System (ADS)

Wang, Xuping; Quan, Long; Xiong, Guangyu

2013-11-01

Currently, most researches use signals, such as the coil current or voltage of solenoid, to identify parameters; typically, parameter identification method based on variation rate of coil current is applied for position estimation. The problem exists in these researches that the detected signals are prone to interference and difficult to obtain. This paper proposes a new method for detecting the core position by using flux characteristic quantity, which adds a new group of secondary winding to the coil of the ordinary switching electromagnet. On the basis of electromagnetic coupling theory analysis and simulation research of the magnetic field regarding the primary and secondary winding coils, and in accordance with the fact that under PWM control mode varying core position and operating current of windings produce different characteristic of flux increment of the secondary winding. The flux increment of the electromagnet winding can be obtained by conducting time domain integration for the induced voltage signal of the extracted secondary winding, and the core position from the two-dimensional fitting curve of the operating winding current and flux-linkage characteristic quantity of solenoid are calculated. The detecting and testing system of solenoid core position is developed based on the theoretical research. The testing results show that the flux characteristic quantity of switching electromagnet magnetic circuit is able to effectively show the core position and thus to accomplish the non-displacement transducer detection of the said core position of the switching electromagnet. This paper proposes a new method for detecting the core position by using flux characteristic quantity, which provides a new theory and method for switch solenoid to control the proportional valve.

Press-coated tablets for time-programmed release of drugs.

PubMed

Conte, U; Maggi, L; Torre, M L; Giunchedi, P; La Manna, A

1993-10-01

A new dry-coated device for the release of drug after a programmable period of time is proposed. It is intended to be used mainly in the therapy of those diseases which depend on circadian rhythms. Some core formulations, characterized by different release rates and mechanisms (containing diltiazem hydrochloride or sodium diclofenac as model drugs), were coated by compression with different polymeric barrier layers (press-coated systems). The shell formulations tested contained either gellable or erodible polymers. The dissolution profiles of uncoated cores and press-coated devices were compared. The gellable and/or erodible characteristics (properties) of the barrier formulations were also examined by means of a penetrometer. The coatings prevent drug release from the core until the polymeric shell is completely eroded or swollen. This delay in release start is not influenced by the core composition and depends only on the shell formulation. Except for the time-lag, the release kinetics of the drug contained in the core are not significantly influenced by the presence of the erodible barrier, but can be widely modulated using a swellable polymeric shell.

Longer biopsy cores do not increase prostate cancer detection rate: A large-scale cohort study refuting cut-off values indicated in the literature

PubMed Central

Yılmaz, Hasan; Yavuz, Ufuk; Üstüner, Murat; Çiftçi, Seyfettin; Yaşar, Hikmet; Müezzinoğlu, Bahar; Uslubaş, Ali Kemal; Dillioğlugil, Özdal

2017-01-01

Objective Only a few papers in the literature aimed to evaluate biopsy core lengths. Additionally, studies evaluated the core length with different approaches. We aimed to determine whether prostate cancer (PCa) detection is affected from core lengths according to three different approaches in a large standard cohort and compare our cut-off values with the published cut-offs. Material and methods We retrospectively analyzed 1,523 initial consecutive transrectal ultrasound-guided 12-core prostate biopsies. Biopsies were evaluated with respect to total core length (total length of each patients’ core) average core length (total core length divided by total number of cores in each patient), and mean core length (mean length of all cores pooled), and compared our cut-off values with the published cut-offs. The prostate volumes were categorized into four groups (<30, 30–59.99, 60–119.99, ≥120 cm3) and PCa detection rates in these categories were examined. Results PCa was found in 41.5% patients. There was no difference between benign and malignant mean core lengths of the pooled cores (p>0.05). Total core length and average core length were not significantly associated with PCa in multivariate logistic regression analyses (p>0.05). The core lengths (mean, average and total core lengths) increased (p<0.001) and PCa rates decreased (p<0.001) steadily with increasing prostate volume categories. PCa percentages decreased in all categories above the utilized cut-offs for mean (p>0.05), average (p<0.05), and total core lengths (p>0.05). Conclusion There was no difference between mean core lengths of benign and malignant cores. Total core length and average core length were not significantly associated with PCa. Contrary to the cut-offs used for mean and average core lengths in the published studies, PCa rates decrease as these core lengths increase. Larger studies are necessary for the determination and acceptance of accurate cut-offs. PMID:28861301

Borehole flowmeter logging for the accurate design and analysis of tracer tests.

PubMed

Basiricò, Stefano; Crosta, Giovanni B; Frattini, Paolo; Villa, Alberto; Godio, Alberto

2015-04-01

Tracer tests often give ambiguous interpretations that may be due to the erroneous location of sampling points and/or the lack of flow rate measurements through the sampler. To obtain more reliable tracer test results, we propose a methodology that optimizes the design and analysis of tracer tests in a cross borehole mode by using vertical borehole flow rate measurements. Experiments using this approach, herein defined as the Bh-flow tracer test, have been performed by implementing three sequential steps: (1) single-hole flowmeter test, (2) cross-hole flowmeter test, and (3) tracer test. At the experimental site, core logging, pumping tests, and static water-level measurements were previously carried out to determine stratigraphy, fracture characteristics, and bulk hydraulic conductivity. Single-hole flowmeter testing makes it possible to detect the presence of vertical flows as well as inflow and outflow zones, whereas cross-hole flowmeter testing detects the presence of connections along sets of flow conduits or discontinuities intercepted by boreholes. Finally, the specific pathways and rates of groundwater flow through selected flowpaths are determined by tracer testing. We conclude that the combined use of single and cross-borehole flowmeter tests is fundamental to the formulation of the tracer test strategy and interpretation of the tracer test results. © 2014, National Ground Water Association.

Retardation of mobile radionuclides in granitic rock fractures by matrix diffusion

NASA Astrophysics Data System (ADS)

Hölttä, P.; Poteri, A.; Siitari-Kauppi, M.; Huittinen, N.

Transport of iodide and sodium has been studied by means of block fracture and core column experiments to evaluate the simplified radionuclide transport concept. The objectives were to examine the processes causing retention in solute transport, especially matrix diffusion, and to estimate their importance during transport in different scales and flow conditions. Block experiments were performed using a Kuru Grey granite block having a horizontally planar natural fracture. Core columns were constructed from cores drilled orthogonal to the fracture of the granite block. Several tracer tests were performed using uranine, 131I and 22Na as tracers at water flow rates 0.7-50 μL min -1. Transport of tracers was modelled by applying the advection-dispersion model based on the generalized Taylor dispersion added with matrix diffusion. Scoping calculations were combined with experiments to test the model concepts. Two different experimental configurations could be modelled applying consistent transport processes and parameters. The processes, advection-dispersion and matrix diffusion, were conceptualized with sufficient accuracy to replicate the experimental results. The effects of matrix diffusion were demonstrated on the slightly sorbing sodium and mobile iodine breakthrough curves.

Integrated modelling of H-mode pedestal and confinement in JET-ILW

NASA Astrophysics Data System (ADS)

Saarelma, S.; Challis, C. D.; Garzotti, L.; Frassinetti, L.; Maggi, C. F.; Romanelli, M.; Stokes, C.; Contributors, JET

2018-01-01

A pedestal prediction model Europed is built on the existing EPED1 model by coupling it with core transport simulation using a Bohm-gyroBohm transport model to self-consistently predict JET-ILW power scan for hybrid plasmas that display weaker power degradation than the IPB98(y, 2) scaling of the energy confinement time. The weak power degradation is reproduced in the coupled core-pedestal simulation. The coupled core-pedestal model is further tested for a 3.0 MA plasma with the highest stored energy achieved in JET-ILW so far, giving a prediction of the stored plasma energy within the error margins of the measured experimental value. A pedestal density prediction model based on the neutral penetration is tested on a JET-ILW database giving a prediction with an average error of 17% from the experimental data when a parameter taking into account the fuelling rate is added into the model. However the model fails to reproduce the power dependence of the pedestal density implying missing transport physics in the model. The future JET-ILW deuterium campaign with increased heating power is predicted to reach plasma energy of 11 MJ, which would correspond to 11-13 MW of fusion power in equivalent deuterium-tritium plasma but with isotope effects on pedestal stability and core transport ignored.

The collapse of a molecular cloud core to stellar densities using radiation non-ideal magnetohydrodynamics

NASA Astrophysics Data System (ADS)

Wurster, James; Bate, Matthew R.; Price, Daniel J.

2018-04-01

We present results from radiation non-ideal magnetohydrodynamics (MHD) calculations that follow the collapse of rotating, magnetized, molecular cloud cores to stellar densities. These are the first such calculations to include all three non-ideal effects: ambipolar diffusion, Ohmic resistivity, and the Hall effect. We employ an ionization model in which cosmic ray ionization dominates at low temperatures and thermal ionization takes over at high temperatures. We explore the effects of varying the cosmic ray ionization rate from ζcr = 10-10 to 10-16 s-1. Models with ionization rates ≳10-12 s-1 produce results that are indistinguishable from ideal MHD. Decreasing the cosmic ray ionization rate extends the lifetime of the first hydrostatic core up to a factor of 2, but the lifetimes are still substantially shorter than those obtained without magnetic fields. Outflows from the first hydrostatic core phase are launched in all models, but the outflows become broader and slower as the ionization rate is reduced. The outflow morphology following stellar core formation is complex and strongly dependent on the cosmic ray ionization rate. Calculations with high ionization rates quickly produce a fast (≈14 km s-1) bipolar outflow that is distinct from the first core outflow, but with the lowest ionization rate, a slower (≈3-4 km s-1) conical outflow develops gradually and seamlessly merges into the first core outflow.

Borehole Tool for the Comprehensive Characterization of Hydrate-bearing Sediments

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

Dai, Sheng; Santamarina, J. Carlos

Reservoir characterization and simulation require reliable parameters to anticipate hydrate deposits responses and production rates. The acquisition of the required fundamental properties currently relies on wireline logging, pressure core testing, and/or laboratory observations of synthesized specimens, which are challenged by testing capabilities and innate sampling disturbances. The project reviews hydrate-bearing sediments, properties, and inherent sampling effects, albeit lessen with the developments in pressure core technology, in order to develop robust correlations with index parameters. The resulting information is incorporated into a tool for optimal field characterization and parameter selection with uncertainty analyses. Ultimately, the project develops a borehole tool formore » the comprehensive characterization of hydrate-bearing sediments at in situ, with the design recognizing past developments and characterization experience and benefited from the inspiration of nature and sensor miniaturization.« less

Quantifying weathering advance rates in basaltic andesite rinds with uranium-series isotopes: a case study from Guadeloupe

NASA Astrophysics Data System (ADS)

Ma, L.; Chabaux, F. J.; Pelt, E.; Granet, M.; Sak, P. B.; Gaillardet, J.; Brantley, S. L.

2010-12-01

Weathering of basaltic rocks plays an important role in many Earth surface processes. It is thus of great interest to quantify their weathering rates. Because of their well-documented behaviors during water-rock interaction, U-series isotopes have been shown to have utility as a potential chronometer to constrain the formation rates of weathering rinds developed on fresh basaltic rocks. In this study, U-series isotopes and trace element concentrations were analyzed in a basaltic andesite weathering rind collected from the Bras David watershed, Guadeloupe. From the clast, core and rind samples were obtained by drilling along a 63.8 mm linear profile across a low curvature segment of the core-rind boundary. Trace element concentrations reveal: significant loss of REE, Y, Rb, Sr, and Ba in the weathering rind; conservative behaviors of Ti and Th; and external addition of U into the rind during clast weathering. Measured (234U/238U) activity ratios of the rind samples are much higher than the core samples and show excess 234U. Measured (238U/232Th) and (230Th/232Th) activity ratios of the core and rind samples increase gradually from the core into the weathering rind. The observed depletion profiles for the trace elements in the clast suggest that the earliest chemical reaction that creates significant porosity is dissolution of plagioclase, consistent with the previous study [Sak et al., 2010, CG, in press]. The porosity growth within the rind allows for an influx of soil solution that carries dissolved U with (234U/238U) activity ratios >1 into the clast. The deposition of U in the rind is most likely associated with precipication of secondary minerals during clast weathering. Such a continuous U addition is responsible for the observed gradual increase of (238U/232Th) activity ratios in the rind. Subsequent production of 230Th in the rind over time from the decay of excess 234U accounts for the observed continuous increase of (230Th/232Th) activity ratios. The U-series activity ratios in the clast were modeled with a weathering advance rate of ~0.3 mm kyr-1. This represents the rind advance rate at the low curvature segment of the core-rind boundary under tropical climate. This rate is consistent with the previously estimated formation rates of basaltic rinds under similar tropic conditions in Costa Rica [Sak et al., 2004, GCA 68, 1453; Pelt et al., 2008, EPSL 276, 98]. This rate is about one order of magnitude greater than those in temperate regions, documenting the important control of temperature on basalt weathering. This work illustrates that the weathering advance rates of rinds can be successfully estimated by U-series isotopes, demonstrating their great potential as dating tools for Earth surface processes. Furthermore, U-series chronometry provides a suitable method for independently testing the hypothesis that rind advance rates around an individual clast increase with increasing interfacial curvature.

A rural, community-based suicide awareness and intervention program.

PubMed

Jones, Sharon; Walker, Coralanne; Miles, Alison C J; De Silva, Eve; Zimitat, Craig

2015-01-01

Suicide is a prominent public health issue in rural Australia and specifically in Tasmania, which has one of the highest suicide rates in the country. The Community Response to Eliminating Suicide (CORES) program was developed in rural Tasmania in response to a significant number of suicides over a short period of time. CORES is unique in that it is both a community-based and gatekeeper education model. CORES aims to build and empower communities to take ownership of suicide prevention strategies. It also aims to increase the individual community member's interpersonal skills and awareness of suicide risks, while building peer support and awareness of suicide prevention support services within the community itself. Pre- and post-test surveys after the CORES 1-day suicide awareness and intervention program (SAIP) showed significant increases in levels of comfort and confidence in discussing suicide with those who may be contemplating that action. CORES builds community capital through establishing new connections within communities. Establishment of local executive groups, funding and SAIP are key activities of successful CORES programs in communities around Australia. Over half of the initial leaders are still actively involved after a decade, which reflects positively on the quality and outcomes of the program. This study supports CORES as a beneficial and feasible community-based suicide intervention program for rural communities.

Simple Learned Weighted Sums of Inferior Temporal Neuronal Firing Rates Accurately Predict Human Core Object Recognition Performance.

PubMed

Majaj, Najib J; Hong, Ha; Solomon, Ethan A; DiCarlo, James J

2015-09-30

To go beyond qualitative models of the biological substrate of object recognition, we ask: can a single ventral stream neuronal linking hypothesis quantitatively account for core object recognition performance over a broad range of tasks? We measured human performance in 64 object recognition tests using thousands of challenging images that explore shape similarity and identity preserving object variation. We then used multielectrode arrays to measure neuronal population responses to those same images in visual areas V4 and inferior temporal (IT) cortex of monkeys and simulated V1 population responses. We tested leading candidate linking hypotheses and control hypotheses, each postulating how ventral stream neuronal responses underlie object recognition behavior. Specifically, for each hypothesis, we computed the predicted performance on the 64 tests and compared it with the measured pattern of human performance. All tested hypotheses based on low- and mid-level visually evoked activity (pixels, V1, and V4) were very poor predictors of the human behavioral pattern. However, simple learned weighted sums of distributed average IT firing rates exactly predicted the behavioral pattern. More elaborate linking hypotheses relying on IT trial-by-trial correlational structure, finer IT temporal codes, or ones that strictly respect the known spatial substructures of IT ("face patches") did not improve predictive power. Although these results do not reject those more elaborate hypotheses, they suggest a simple, sufficient quantitative model: each object recognition task is learned from the spatially distributed mean firing rates (100 ms) of ∼60,000 IT neurons and is executed as a simple weighted sum of those firing rates. Significance statement: We sought to go beyond qualitative models of visual object recognition and determine whether a single neuronal linking hypothesis can quantitatively account for core object recognition behavior. To achieve this, we designed a database of images for evaluating object recognition performance. We used multielectrode arrays to characterize hundreds of neurons in the visual ventral stream of nonhuman primates and measured the object recognition performance of >100 human observers. Remarkably, we found that simple learned weighted sums of firing rates of neurons in monkey inferior temporal (IT) cortex accurately predicted human performance. Although previous work led us to expect that IT would outperform V4, we were surprised by the quantitative precision with which simple IT-based linking hypotheses accounted for human behavior. Copyright © 2015 the authors 0270-6474/15/3513402-17$15.00/0.

Performance of ARCHITECT HCV core antigen test with specimens from US plasma donors and injecting drug users.

PubMed

Mixson-Hayden, Tonya; Dawson, George J; Teshale, Eyasu; Le, Thao; Cheng, Kevin; Drobeniuc, Jan; Ward, John; Kamili, Saleem

2015-05-01

Hepatitis C virus (HCV) core antigen is a serological marker of current HCV infection. The aim of this study was mainly to evaluate the performance characteristics of the ARCHITECT HCV core antigen assay with specimens from US plasma donors and injecting drug users. A total of 551 serum and plasma samples with known anti-HCV and HCV RNA status were tested for HCV core antigen using the Abbott ARCHITECT HCV core antigen test. HCV core antigen was detectable in 100% of US plasma donor samples collected during the pre-seroconversion phase of infection (anti-HCV negative/HCV RNA positive). Overall sensitivity of the HCV core antigen assay was 88.9-94.3% in samples collected after seroconversion. The correlation between HCV core antigen and HCV RNA titers was 0.959. HCV core antigen testing may be reliably used to identify current HCV infection. Published by Elsevier B.V.

Solid-phase microextraction may catalize hydrogenation when using hydrogen as carrier in gas chromatography.

PubMed

Fiorini, D; Boarelli, M C

2016-07-01

When hydrogen is used as carrier gas, carbon-carbon double bonds may be hydrogenated in the hot gas chromatograph (GC) injector if introduced by solid-phase microextraction (SPME). SPME fibers coated with polydimethylsiloxane (PDMS)/carboxen/divinylbenzene (DVB), PDMS/carboxen, polyacrylate, PDMS/DVB and PDMS on fused silica, stableflex or metal alloy core have been tested with fatty acid methyl esters (FAMEs) from olive oil. Using coatings containing DVB, hydrogenation took place with high conversion rates (82.0-92.9%) independently of the core material. With all fibers having a metal core, hydrogenation was observed to a certain extent (27.4-85.3%). PDMS, PDMS/carboxen and polyacrylate coated fibers with a fused silica or stableflex core resulted in negligible hydrogenation (0.2-2.5%). The occurrence of hydrogenation was confirmed also with other substances containing carbon-carbon double bonds (n-alkenes, alkenoic acids, mono- and polyunsaturated fatty acid methyl and ethyl esters). Copyright © 2016 Elsevier B.V. All rights reserved.

Sensitivity of geomagnetic reversal rate on core evolution from numerical dynamos

NASA Astrophysics Data System (ADS)

Driscoll, P. E.; Davies, C. J.

2017-12-01

The paleomagnetic record indicates the geodynamo has evolved from frequently reversing to non-reversing (superchron) magnetic states several times over the Phanerozoic. Previous theoretical studies demonstrated a positive correlation between magnetic reversal rate and core-mantle boundary heat flux. However, attempts to identify such a correlation between reversal rates and proxies for internal cooling rate, such as plume events, superchron cycles, and subduction rates, have been inconclusive. Here we revisit the magnetic reversal occurrence rate in numerical dynamos at low Ekman numbers (faster rotation) and high magnetic Prandtl numbers (ratio of viscous and magnetic diffusivities). We focus on how the correlation between reversal rate and convective power depends on the core evolution rate and on other factors, such as Ek, Pm, and thermal boundary conditions. We apply our results to the seafloor reversal record in an attempt to infer the energetic evolution of the lower mantle and core over that period.

Diagnostic Yield of CT-Guided Percutaneous Transthoracic Needle Biopsy for Diagnosis of Anterior Mediastinal Masses.

PubMed

Petranovic, Milena; Gilman, Matthew D; Muniappan, Ashok; Hasserjian, Robert P; Digumarthy, Subba R; Muse, Victorine V; Sharma, Amita; Shepard, Jo-Anne O; Wu, Carol C

2015-10-01

The purpose of this study was to evaluate the diagnostic yield and accuracy of CT-guided percutaneous biopsy of anterior mediastinal masses and assess prebiopsy characteristics that may help to select patients with the highest diagnostic yield. Retrospective review of all CT-guided percutaneous biopsies of the anterior mediastinum conducted at our institution from January 2003 through December 2012 was performed to collect data regarding patient demographics, imaging characteristics of biopsied masses, presence of complications, and subsequent surgical intervention or medical treatment (or both). Cytology, core biopsy pathology, and surgical pathology results were recorded. A per-patient analysis was performed using two-tailed t test, Fisher's exact test, and Pearson chi-square test. The study cohort included 52 patients (32 men, 20 women; mean age, 49 years) with mean diameter of mediastinal mass of 6.9 cm. Diagnostic yield of CT-guided percutaneous biopsy was 77% (40/52), highest for thymic neoplasms (100% [11/11]). Non-diagnostic results were seen in 12 of 52 patients (23%), primarily in patients with lymphoma (75% [9/12]). Fine-needle aspiration yielded the correct diagnosis in 31 of 52 patients (60%), and core biopsy had a diagnostic rate of 77% (36/47). None of the core biopsies were discordant with surgical pathology. There was no statistically significant difference between the diagnostic and the nondiagnostic groups in patient age, lesion size, and presence of necrosis. The complication rate was 3.8% (2/52), all small self-resolving pneumothoraces. CT-guided percutaneous biopsy is a safe diagnostic procedure with high diagnostic yield (77%) for anterior mediastinal lesions, highest for thymic neoplasms (100%), and can potentially obviate more invasive procedures.

The Effect of Inner Core Translation on Outer Core Flow and the Geomagnetic Field

NASA Astrophysics Data System (ADS)

Mound, J. E.; Davies, C. J.; Silva, L.

2015-12-01

Bulk translation of the inner core has been proposed to explain quasi-hemispheric patterns of seismic heterogeneity. Such a translation would result in differential melting and freezing at the inner core boundary (ICB) and hence a heterogeneous pattern of buoyancy flux that could influence convection in the outer core. This heterogeneous flux at the ICB will tend to promote upwelling on the trailing hemisphere, where enhanced inner core growth results in increased latent heat and light element release, and inhibit upwelling on the leading hemisphere, where melting of the inner core occurs. If this difference in convective driving between the two hemispheres propagated across the thickness of the outer core, then flows near the surface of the core could be linked to the ICB heterogeneity and result in a hemispheric imbalance in the geomagnetic field. We have investigated the influence of such ICB boundary conditions on core flows and magnetic field structure in numerical geodynamo models and analysed the resultant hemispheric imbalance relative to the hemispheric structure in models constructed from observations of Earth's field. Inner core translation at rates consistent with estimates for the Earth produce a strong hemispheric bias in the field, one that should be readily apparent in averages of the field over tens of thousands of years. Current models of the field over the Holocene may be able to rule out the most extreme ICB forcing scenarios, but more information on the dynamic structure of the field over these time scales will be needed to adequately test all cases.

Altering Reservoir Wettability to Improve Production from Single Wells

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

W. W. Weiss

2006-09-30

Many carbonate reservoirs are naturally fractured and typically produce less than 10% original oil in place during primary recovery. Spontaneous imbibition has proven an important mechanism for oil recovery from fractured reservoirs, which are usually weak waterflood candidates. In some situations, chemical stimulation can promote imbibition of water to alter the reservoir wettability toward water-wetness such that oil is produced at an economic rate from the rock matrix into fractures. In this project, cores and fluids from five reservoirs were used in laboratory tests: the San Andres formation (Fuhrman Masho and Eagle Creek fields) in the Permian Basin of Texasmore » and New Mexico; and the Interlake, Stony Mountain, and Red River formations from the Cedar Creek Anticline in Montana and South Dakota. Solutions of nonionic, anionic, and amphoteric surfactants with formation water were used to promote waterwetness. Some Fuhrman Masho cores soaked in surfactant solution had improved oil recovery up to 38%. Most Eagle Creek cores did not respond to any of the tested surfactants. Some Cedar Creek anticline cores had good response to two anionic surfactants (CD 128 and A246L). The results indicate that cores with higher permeability responded better to the surfactants. The increased recovery is mainly ascribed to increased water-wetness. It is suspected that rock mineralogy is also an important factor. The laboratory work generated three field tests of the surfactant soak process in the West Fuhrman Masho San Andres Unit. The flawlessly designed tests included mechanical well clean out, installation of new pumps, and daily well tests before and after the treatments. Treatments were designed using artificial intelligence (AI) correlations developed from 23 previous surfactant soak treatments. The treatments were conducted during the last quarter of 2006. One of the wells produced a marginal volume of incremental oil through October. It is interesting to note that the field tests were conducted in an area of the field that has not met production expectations. The dataset on the 23 Phosphoria well surfactant soaks was updated. An analysis of the oil decline curves indicted that 4.5 lb of chemical produced a barrel of incremental oil. The AI analysis supports the adage 'good wells are the best candidates.' The generally better performance of surfactant in the high permeability core laboratory tests supports this observation. AI correlations were developed to predict the response to water-frac stimulations in a tight San Andres reservoir. The correlations maybe useful in the design of Cedar Creek Anticline surfactant soak treatments planned for next year. Nuclear Magnetic Resonance scans of dolomite cores to measure porosity and saturation during the high temperature laboratory work were acquired. The scans could not be correlated with physical measurement using either conventional or AI methods.« less

Electrosprayed Multi-Core Alginate Microcapsules as Novel Self-Healing Containers

NASA Astrophysics Data System (ADS)

Hia, Iee Lee; Pasbakhsh, Pooria; Chan, Eng-Seng; Chai, Siang-Piao

2016-10-01

Alginate microcapsules containing epoxy resin were developed through electrospraying method and embedded into epoxy matrix to produce a capsule-based self-healing composite system. These formaldehyde free alginate/epoxy microcapsules were characterized via light microscope, field emission scanning electron microscope, fourier transform infrared spectroscopy and thermogravimetric analysis. Results showed that epoxy resin was successfully encapsulated within alginate matrix to form porous (multi-core) microcapsules with pore size ranged from 5-100 μm. The microcapsules had an average size of 320 ± 20 μm with decomposition temperature at 220 °C. The loading capacity of these capsules was estimated to be 79%. Under in situ healing test, impact specimens showed healing efficiency as high as 86% and the ability to heal up to 3 times due to the multi-core capsule structure and the high impact energy test that triggered the released of epoxy especially in the second and third healings. TDCB specimens showed one-time healing only with the highest healing efficiency of 76%. The single healing event was attributed by the constant crack propagation rate of TDCB fracture test. For the first time, a cost effective, environmentally benign and sustainable capsule-based self-healing system with multiple healing capabilities and high healing performance was developed.

Electrosprayed Multi-Core Alginate Microcapsules as Novel Self-Healing Containers.

PubMed

Hia, Iee Lee; Pasbakhsh, Pooria; Chan, Eng-Seng; Chai, Siang-Piao

2016-10-03

Alginate microcapsules containing epoxy resin were developed through electrospraying method and embedded into epoxy matrix to produce a capsule-based self-healing composite system. These formaldehyde free alginate/epoxy microcapsules were characterized via light microscope, field emission scanning electron microscope, fourier transform infrared spectroscopy and thermogravimetric analysis. Results showed that epoxy resin was successfully encapsulated within alginate matrix to form porous (multi-core) microcapsules with pore size ranged from 5-100 μm. The microcapsules had an average size of 320 ± 20 μm with decomposition temperature at 220 °C. The loading capacity of these capsules was estimated to be 79%. Under in situ healing test, impact specimens showed healing efficiency as high as 86% and the ability to heal up to 3 times due to the multi-core capsule structure and the high impact energy test that triggered the released of epoxy especially in the second and third healings. TDCB specimens showed one-time healing only with the highest healing efficiency of 76%. The single healing event was attributed by the constant crack propagation rate of TDCB fracture test. For the first time, a cost effective, environmentally benign and sustainable capsule-based self-healing system with multiple healing capabilities and high healing performance was developed.

Electrosprayed Multi-Core Alginate Microcapsules as Novel Self-Healing Containers

PubMed Central

Hia, Iee Lee; Pasbakhsh, Pooria; Chan, Eng-Seng; Chai, Siang-Piao

2016-01-01

Alginate microcapsules containing epoxy resin were developed through electrospraying method and embedded into epoxy matrix to produce a capsule-based self-healing composite system. These formaldehyde free alginate/epoxy microcapsules were characterized via light microscope, field emission scanning electron microscope, fourier transform infrared spectroscopy and thermogravimetric analysis. Results showed that epoxy resin was successfully encapsulated within alginate matrix to form porous (multi-core) microcapsules with pore size ranged from 5–100 μm. The microcapsules had an average size of 320 ± 20 μm with decomposition temperature at 220 °C. The loading capacity of these capsules was estimated to be 79%. Under in situ healing test, impact specimens showed healing efficiency as high as 86% and the ability to heal up to 3 times due to the multi-core capsule structure and the high impact energy test that triggered the released of epoxy especially in the second and third healings. TDCB specimens showed one-time healing only with the highest healing efficiency of 76%. The single healing event was attributed by the constant crack propagation rate of TDCB fracture test. For the first time, a cost effective, environmentally benign and sustainable capsule-based self-healing system with multiple healing capabilities and high healing performance was developed. PMID:27694922

78 FR 63516 - Initial Test Program of Emergency Core Cooling Systems for New Boiling-Water Reactors

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-24

... NUCLEAR REGULATORY COMMISSION [NRC-2012-0134] Initial Test Program of Emergency Core Cooling....79.1, ``Initial Test Program of Emergency Core Cooling Systems for New Boiling-Water Reactors.'' This... emergency core cooling systems (ECCSs) for boiling- water reactors (BWRs) whose licenses are issued after...

Effects of Oxidation on Oxidation-Resistant Graphite

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

Windes, William; Smith, Rebecca; Carroll, Mark

2015-05-01

The Advanced Reactor Technology (ART) Graphite Research and Development Program is investigating doped nuclear graphite grades that exhibit oxidation resistance through the formation of protective oxides on the surface of the graphite material. In the unlikely event of an oxygen ingress accident, graphite components within the VHTR core region are anticipated to oxidize so long as the oxygen continues to enter the hot core region and the core temperatures remain above 400°C. For the most serious air-ingress accident which persists over several hours or days the continued oxidation can result in significant structural damage to the core. Reducing the oxidationmore » rate of the graphite core material during any air-ingress accident would mitigate the structural effects and keep the core intact. Previous air oxidation testing of nuclear-grade graphite doped with varying levels of boron-carbide (B4C) at a nominal 739°C was conducted for a limited number of doped specimens demonstrating a dramatic reduction in oxidation rate for the boronated graphite grade. This report summarizes the conclusions from this small scoping study by determining the effects of oxidation on the mechanical strength resulting from oxidation of boronated and unboronated graphite to a 10% mass loss level. While the B4C additive did reduce mechanical strength loss during oxidation, adding B4C dopants to a level of 3.5% or more reduced the as-fabricated compressive strength nearly 50%. This effectively minimized any benefits realized from the protective film formed on the boronated grades. Future work to infuse different graphite grades with silicon- and boron-doped material as a post-machining conditioning step for nuclear components is discussed as a potential solution for these challenges in this report.« less

Checkerboard seed-blanket thorium fuel core concepts for heavy water moderated reactors

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

Bromley, B.P.; Hyland, B.

2013-07-01

New reactor concepts to implement thorium-based fuel cycles have been explored to achieve maximum resource utilization. Pressure tube heavy water reactors (PT-HWR) are highly advantageous for implementing the use of thorium-based fuels because of their high neutron economy and on-line re-fuelling capability. The use of heterogeneous seed-blanket core concepts in a PT-HWR where higher-fissile-content seed fuel bundles are physically separate from lower-fissile-content blanket bundles allows more flexibility and control in fuel management to maximize the fissile utilization and conversion of fertile fuel. The lattice concept chosen was a 35-element bundle made with a homogeneous mixture of reactor grade Pu (aboutmore » 67 wt% fissile) and Th, and with a central zirconia rod to help reduce coolant void reactivity. Several checkerboard heterogeneous seed-blanket core concepts with plutonium-thorium-based fuels in a 700-MWe-class PT-HWR were analyzed, using a once-through thorium (OTT) cycle. Different combinations of seed and blanket fuel were tested to determine the impact on core-average burnup, fissile utilization, power distributions, and other performance parameters. It was found that various checkerboard core concepts can achieve a fissile utilization that is up to 26% higher than that achieved in a PT-HWR using more conventional natural uranium fuel bundles. Up to 60% of the Pu is consumed; up to 43% of the energy is produced from thorium, and up to 303 kg/year of Pa-233/U-233/U-235 are produced. Checkerboard cores with about 50% of low-power blanket bundles may require power de-rating (65% to 74%) to avoid exceeding maximum limits for channel and bundle powers and linear element ratings. (authors)« less

Annular seed-blanket thorium fuel core concepts for heavy water moderated reactors

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

Bromley, B.P.; Hyland, B.

2013-07-01

New reactor concepts to implement thorium-based fuel cycles have been explored to achieve maximum resource utilization. Pressure tube heavy water reactors (PT-HWR) are highly advantageous for implementing the use of thorium-based fuels because of their high neutron economy and on-line re-fuelling capability. The use of heterogeneous seed-blanket core concepts in a PT-HWR where higher-fissile-content seed fuel bundles are physically separate from lower-fissile-content blanket bundles allows more flexibility and control in fuel management to maximize the fissile utilization and conversion of fertile fuel. The lattice concept chosen is a 35-element bundle made with a homogeneous mixture of reactor grade Pu andmore » Th, and with a central zirconia rod to help reduce coolant void reactivity. Several annular heterogeneous seed-blanket core concepts with plutonium-thorium-based fuels in a 700-MWe-class PT-HWR were analyzed, using a once-through thorium (OTT) cycle. Different combinations of seed and blanket fuel were tested to determine the impact on core-average burnup, fissile utilization, power distributions, and other performance parameters. It was found that the various core concepts can achieve a fissile utilization that is up to 30% higher than is currently achieved in a PT-HWR using conventional natural uranium fuel bundles. Up to 67% of the Pu is consumed; up to 43% of the energy is produced from thorium, and up to 363 kg/year of U-233 is produced. Seed-blanket cores with ∼50% content of low-power blanket bundles may require power de-rating (∼58% to 65%) to avoid exceeding maximum limits for peak channel power, bundle power and linear element ratings. (authors)« less

Upgrade of ductal carcinoma in situ on core biopsies to invasive disease at final surgery: a retrospective review across the Scottish Breast Screening Programme.

PubMed

Sim, Y T; Litherland, J; Lindsay, E; Hendry, P; Brauer, K; Dobson, H; Cordiner, C; Gagliardi, T; Smart, L

2015-05-01

To identify factors affecting upgrade rates from B5a (non-invasive) preoperative core biopsies to invasive disease at surgery and ways to improve screening performance. This was a retrospective analysis of 1252 cases of B5a biopsies across all six Scottish Breast Screening Programmes (BSPs), ranging between 2004 and 2012. Final surgical histopathology was correlated with radiological and biopsy factors. Data were analysed using basic Microsoft Excel and standard Chi-squared test used for evaluating statistical significance. B5a upgrade rates for the units ranged from 19.2% to 29.2%, with an average of 23.6%. Mean sizes of invasive tumours were small (3-11 mm). The upgrade rate was significantly higher for cases where the main mammographic abnormality was mass, distortion, or asymmetry, compared with micro-calcification alone (33.2% versus 21.7%, p = 0.0004). The upgrade rate was significantly lower with the use of large-volume vacuum-assisted biopsy (VAB) devices than 14 G core needles (19.9% versus 26%, p = 0.013); in stereotactic than ultrasound-guided biopsies (21.2% versus 36.1%, p < 0.001). Heterogeneity of data from different centres limited evaluation of other potential factors. Upgrade rates are lower for cases with micro-calcification as the sole mammographic feature with the use of VAB devices. Nevertheless, there is variation in practice across Scottish BSPs, including first-line biopsy technique and/or device; and it is of interest that a few centres maintain low upgrade rates despite not using VAB routinely for biopsy of micro-calcification. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Control of skin blood flow, sweating, and heart rate - Role of skin vs. core temperature

NASA Technical Reports Server (NTRS)

Wyss, C. R.; Brengelmann, G. L.; Johnson, J. M.; Rowell, L. B.; Niederberger, M.

1974-01-01

A study was conducted to generate quantitative expressions for the influence of core temperature, skin temperature, and the rate of change of skin temperature on sweat rate, skin blood flow, and heart rate. A second goal of the study was to determine whether the use of esophageal temperature rather than the right atrial temperature as a measure of core temperature would lead to different conclusions about the control of measured effector variables.

SPERT Destructive Test - I on Aluminum, Highly Enriched Plate Type Core

ScienceCinema

None

2018-01-16

SPERT - Special Power Excursion Reactor Tests Destructive Test number 1 On Aluminum, Highly Enriched Plate Type Core. A test studying the behavior of the reactor under destructive conditions on a light water moderated pool-type reactor with a plate-type core.

Exploring mechanisms of change in schema therapy for chronic depression.

PubMed

Renner, Fritz; DeRubeis, Robert; Arntz, Arnoud; Peeters, Frenk; Lobbestael, Jill; Huibers, Marcus J H

2018-03-01

The underlying mechanisms of symptom change in schema therapy (ST) for chronic major depressive disorder (cMDD) have not been studied. The aim of this study was to explore the impact of two potentially important mechanisms of symptom change, maladaptive schemas (proxied by negative idiosyncratic core-beliefs) and the therapeutic alliance. We drew data from a single-case series of ST for cMDD. Patients with cMDD (N = 20) received on average 78 repeated weekly assessments over a course of up to 65 individual sessions of ST. Focusing on repeated assessments within-individuals, we used mixed regression to test whether change in core-beliefs and therapeutic alliance preceded, followed, or occurred concurrently with change in depressive symptoms. Changes in core-beliefs did not precede but were concurrently related to changes in symptoms. Repeated goal and task agreement ratings (specific aspects of alliance) of the same session, completed on separate days, were at least in part associated with concurrent changes in symptoms. By design this study had a small sample-size and no control group. Contrary to what would be expected based on theory, our findings suggest that change in core-beliefs does not precede change in symptoms. Instead, change in these variables occurs concurrently. Moreover, alliance ratings seem to be at least in part colored by changes in current mood state. Copyright © 2017 Elsevier Ltd. All rights reserved.

OECD MCCI project 2-D Core Concrete Interaction (CCI) tests : CCI-3 test data report-thermalhydraulic results. Rev. 0 October 15, 2005.

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

Farmer, M. T.; Lomperski, S.; Kilsdonk, D. J.

The Melt Attack and Coolability Experiments (MACE) program addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. As a follow-on program to MACE, The Melt Coolability and Concrete Interaction Experiments (MCCI) project is conducting reactor material experiments and associated analysis to achieve the following objectives: (1)more » resolve the ex-vessel debris coolability issue through a program that focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests, and (2) address remaining uncertainties related to long-term two-dimensional molten core-concrete interactions under both wet and dry cavity conditions. Achievement of these two program objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs for future plants. In terms of satisfying these objectives, the Management Board (MB) approved the conduct of a third long-term 2-D Core-Concrete Interaction (CCI) experiment designed to provide information in several areas, including: (i) lateral vs. axial power split during dry core-concrete interaction, (ii) integral debris coolability data following late phase flooding, and (iii) data regarding the nature and extent of the cooling transient following breach of the crust formed at the melt-water interface. This data report provides thermal hydraulic test results from the CCI-3 experiment, which was conducted on September 22, 2005. Test specifications for CCI-3 are provided in Table 1-1. This experiment investigated the interaction of a fully oxidized 375 kg PWR core melt, initially containing 15 wt% siliceous concrete, with a specially designed two-dimensional siliceous concrete test section with an initial cross-sectional area of 50 cm x 50 cm. The sand and aggregate constituents for this particular siliceous concrete were provided by CEA as an in-kind contribution to the program. The report begins by providing a summary description of the CCI-3 test apparatus and operating procedures, followed by presentation of the thermal-hydraulic results. Detailed posttest debris examination results will be provided in a subsequent publication. Observations drawn within this report regarding the overall cavity erosion behavior may be subject to revision once the posttest examinations are completed, since these examinations will fully reveal the final cavity shape.« less

Determining rates of sediment accumulation on the Mekong shelf: Timescales, steady-state assumptions, and radiochemical tracers

NASA Astrophysics Data System (ADS)

DeMaster, D. J.; Liu, J. P.; Eidam, E.; Nittrouer, C. A.; Nguyen, T. T.

2017-09-01

Thirty-two kasten cores, collected from the proximal Mekong continental shelf, have been analyzed for their excess 210Pb distributions in an effort to establish rates of sediment accumulation over the past 100 years. The length of the cores varied from 0.5 to 3 m, and stations sampled topset, foreset, and bottomset beds (water depths 7-21 m). Apparent excess 210Pb sediment accumulation rates ranged from > 10 cm/y (no down-core decrease of excess activity over 300 cm core length) near the Song Hau river mouth, to 1-3 cm/y in topset and foreset beds within 20-50 km of the river mouth, to rates as low as 0.4 cm/y in cores from bottomset beds. The 210Pb sediment accumulation rates yield an overall sediment burial rate of 6.1 × 1013 g/y for the proximal deltaic deposits, which corresponds to 43% of the total modern Mekong sediment burial on the southern Vietnam shelf (1.4 × 1014 g/y; based on our 210Pb and seismic data and 210Pb data from the literature). This shelf burial rate is in reasonable agreement with current long-term estimates of Mekong River sediment discharge (1.3-1.6 × 1014 g/y) from the literature. The inventory of excess 210Pb in the proximal Mekong deltaic deposits indicates that the shoreward flow of offshore water (entrained during river/ocean mixing) is approximately twice the flow of the Mekong freshwater discharge. Organic-carbon 14C ages were measured on 10 cores from the proximal Mekong delta and compared to 210Pb sediment accumulation rates in the same core. The 210Pb accumulation rates in all 10 cores were considered to be more robust and accurate than the 14C geochronologies, primarily because of down-core variations in the source of organic carbon deposited on the seafloor (old terrestrial carbon versus younger marine carbon). Variations in the source of organic carbon accumulating in the seabed were resolved by measuring the δ13C value of the seabed organic carbon.

Numerical simulation and experimental study of heat-fluid-solid coupling of double flapper-nozzle servo valve

NASA Astrophysics Data System (ADS)

Zhao, Jianhua; Zhou, Songlin; Lu, Xianghui; Gao, Dianrong

2015-09-01

The double flapper-nozzle servo valve is widely used to launch and guide the equipment. Due to the large instantaneous flow rate of servo valve working under specific operating conditions, the temperature of servo valve would reach 120°C and the valve core and valve sleeve deform in a short amount of time. So the control precision of servo valve significantly decreases and the clamping stagnation phenomenon of valve core appears. In order to solve the problem of degraded control accuracy and clamping stagnation of servo valve under large temperature difference circumstance, the numerical simulation of heat-fluid-solid coupling by using finite element method is done. The simulation result shows that zero position leakage of servo valve is basically impacted by oil temperature and change of fit clearance. The clamping stagnation is caused by warpage-deformation and fit clearance reduction of the valve core and valve sleeve. The distribution rules of the temperature and thermal-deformation of shell, valve core and valve sleeve and the pressure, velocity and temperature field of flow channel are also analyzed. Zero position leakage and electromagnet's current when valve core moves in full-stroke are tested using Electro-hydraulic Servo-valve Characteristic Test-bed of an aerospace sciences and technology corporation. The experimental results show that the change law of experimental current at different oil temperatures is roughly identical to simulation current. The current curve of the electromagnet is smooth when oil temperature is below 80°C, but the amplitude of current significantly increases and the hairy appears when oil temperature is above 80°C. The current becomes smooth again after the warped valve core and valve sleeve are reground. It indicates that clamping stagnation is caused by warpage-deformation and fit clearance reduction of valve core and valve sleeve. This paper simulates and tests the heat-fluid-solid coupling of double flapper-nozzle servo valve, and the obtained results provide the reference value for the design of double flapper-nozzle force feedback servo valve.

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

Miller, D. H.; Reigel, M. M.

A full-scale formed core sampler was designed and functionally tested for use in the Saltstone Disposal Facility (SDF). Savannah River National Laboratory (SRNL) was requested to compare properties of the formed core samples and core drilled samples taken from adjacent areas in the full-scale sampler. While several physical properties were evaluated, the primary property of interest was hydraulic conductivity. Differences in hydraulic conductivity between the samples from the formed core sampler and those representing the bulk material were noted with respect to the initial handling and storage of the samples. Due to testing conditions, the site port samples were exposedmore » to uncontrolled temperature and humidity conditions prior to testing whereas the formed core samples were kept in sealed containers with minimal exposure to an uncontrolled environment prior to testing. Based on the results of the testing, no significant differences in porosity or density were found between the formed core samples and those representing the bulk material in the test stand.« less

[Cultural and trivial knowledge among Chilean university students].

PubMed

Vargas C, Nelson A; Pinochet T, Dante; Juárez E, Paula

2010-03-01

Culture is defined by the Webster's dictionary as acquaintance with and taste in fine arts, humanities, and broad aspects of science as distinguished from vocational and technical skills. To assess the general cultural knowledge of university students. A test containing 58 questions about art, national and universal literature, national and universal history, mythology science and trivial national issues was designed and applied to 251 medical students in Santiago (149 from first year and 86 from fifth year, Universidad de Chile) and 138 agronomy students in Valdivia (61 from first year and 77 from fifth year, Universidad Austral de Chile). All students answered the test. Medical students from first and fifth year omitted 19 and 15% of questions respectively The figures for first and fifth year agronomy students were 23% each. The percentage of cored answers among first and fifth year medical students was 50 and 59% respectively. The figures for first and fifth year agronomy students were 39 and 44% respectively. The questions with higher rates of cored answers were those about trivial issues. There was a high rate of omissions and wrong answers about general cultural issues among university students particularly in national cultural subjects.

Comparison of aquifer characterization approaches through steady state groundwater model validation: A controlled laboratory sandbox study

USGS Publications Warehouse

Illman, W.A.; Zhu, J.; Craig, A.J.; Yin, D.

2010-01-01

Groundwater modeling has become a vital component to water supply and contaminant transport investigations. An important component of groundwater modeling under steady state conditions is selecting a representative hydraulic conductivity (K) estimate or set of estimates which defines the K field of the studied region. Currently, there are a number of characterization approaches to obtain K at various scales and in varying degrees of detail, but there is a paucity of information in terms of which characterization approach best predicts flow through aquifers or drawdowns caused by some drawdown inducing events. The main objective of this paper is to assess K estimates obtained by various approaches by predicting drawdowns from independent cross-hole pumping tests and total flow rates through a synthetic heterogeneous aquifer from flow-through tests. Specifically, we (1) characterize a synthetic heterogeneous aquifer built in the sandbox through various techniques (permeameter analyses of core samples, single-hole, cross-hole, and flow-through testing), (2) obtain mean K fields through traditional analysis of test data by treating the medium to be homogeneous, (3) obtain heterogeneous K fields through kriging and steady state hydraulic tomography, and (4) conduct forward simulations of 16 independent pumping tests and six flowthrough tests using these homogeneous and heterogeneous K fields and comparing them to actual data. Results show that the mean K and heterogeneous K fields estimated through kriging of small-scale K data (core and single-hole tests) yield biased predictions of drawdowns and flow rates in this synthetic heterogeneous aquifer. In contrast, the heterogeneous K distribution or ?K tomogram? estimated via steady state hydraulic tomography yields excellent predictions of drawdowns of pumping tests not used in the construction of the tomogram and very good estimates of total flow rates from the flowthrough tests. These results suggest that steady state groundwater model validation is possible in this laboratory sandbox aquifer if the heterogeneous K distribution and forcing functions (boundary conditions and source/sink terms) are characterized sufficiently. ?? 2010 by the American Geophysical Union.

Modelling the impacts of barrier-island transgression and anthropogenic disturbance on blue carbon budgets

NASA Astrophysics Data System (ADS)

Theuerkauf, E. J.; Rodriguez, A. B.

2017-12-01

The size of backbarrier saltmarsh carbon reservoirs are dictated by transgressive processes, such as erosion and overwash, yet these processes are not included in blue carbon budgets. These carbon reservoirs are presumed to increase through time if marsh elevation is keeping pace with sea-level rise. However, changes in marsh width due to erosion and overwash can alter carbon budgets and reservoirs. To explore the impacts of these processes on transgressive barrier island carbon budgets and reservoirs we developed and tested a transect model. The model couples a carbon storage term driven by backbarrier marsh width and a carbon export term driven by ocean and backbarrier shoreline erosion. We tested the model using data collected from two transgressive barrier islands in North Carolina with different backbarrier settings. Core Banks is an undeveloped barrier island with a wide backbarrier marsh and lagoon, hence, landward migration of the island (rollover) is unimpeded. Barrier rollover is impeded at Onslow Beach as there is no backbarrier lagoon and the island is immediately adjacent to steeper mainland topography. Sediment cores were collected to determine carbon storage rates as well as the quantity of carbon exported from eroding marsh. Backbarrier marsh erosion rates, ocean shoreline erosion rates, and changes in marsh width were determined from aerial photographs. Output from the model indicated that hurricane erosion and overwash as well as human disturbance from the construction of the Intracoastal Waterway temporarily transitioned the Onslow Beach sites to carbon sources. Through time, the carbon reservoir at this barrier continued to decrease as carbon export outpaced carbon storage. The carbon reservoir will continue to exhaust as the ocean shoreline migrates landward given the inability for new marsh to form during island rollover. At Core Banks, barrier rollover is unimpeded and new saltmarsh can form during transgression. The Core Banks site only briefly became a carbon source during an erosive period; otherwise the island functioned as a carbon sink and the reservoir increased across the past century. Our model results indicate barrier island setting controls the sustainability of the carbon reservoir and that transgressive processes should be included in coastal carbon budgets.

A genotype independent, full-genome reverse-transcription protocol for HCV genotyping and resistance testing.

PubMed

Walker, Andreas; Bergmann, Matthias; Camdereli, Jennifer; Kaiser, Rolf; Lübke, Nadine; Timm, Jörg

2017-06-01

HCV treatment options and cure rates have tremendously increased in the last decade. Although a pan-genotype HCV treatment has recently been approved, most DAA therapies are still genotype specific. Resistance-associated variants (RAVs) can limit the efficacy of DAA therapy and are associated with increased risk for therapy failure. With the approval of DAA regimens that recommend resistance testing prior to therapy, correct assessment of the genotype and testing for viruses with RAVs is clinically relevant. However, genotyping and resistance testing is generally done in costly and laborious separate reactions. The aim of the study was to establish a genotype-independent full-genome reverse transcription protocol to generate a template for both genotyping and resistance testing and to implement it into our routine diagnostic setup. The complete HCV genome was reverse transcribed with a pan-genotype primer binding at the 3'end of the viral RNA. This cDNA served as template for transcription of the genotyping amplicon in the core region as well as for the resistance testing of NS3, NS5A, and NS5B. With the established RT-protocol the HCV core region was successfully amplified and genotyped from 124 out of 125 (99.2%) HCV-positive samples. The amplification efficiency of RAV containing regions in NS3, NS5A, NS5B was 96.2%, 96.6% and 94.4%, respectively. We developed a method for HCV full-genome cDNA synthesis and implemented it into a routine diagnostic setup. This cDNA can be used as template for genotyping amplicons covering the core or NS5B region as well as for resistance testing amplicons in NS3, NS5A and NS5B. Copyright © 2017 Elsevier B.V. All rights reserved.

SpaceFibre: The Standard, Simulation, IP Cores and Test Equipment

NASA Astrophysics Data System (ADS)

Parkes, Steve; McClements, Chris; McLaren, David; Ferrer Florit, Albert; Gonzalez Villafranca, Alberto

2015-09-01

SpaceFibre is an emerging new standard for spacecraft on-board data-handling networks. Initially targeted to deliver multi-Gbit/s data rates for synthetic aperture radar and high-resolution, multi-spectral imaging instruments, SpaceFibre has developed into a unified network technology that integrates high bandwidth, with low latency, quality of service (QoS) and fault detection, isolation and recovery (FDIR). Furthermore SpaceFibre is backwards compatible with the widely used SpaceWire standard at the network level allowing simple interconnection of existing SpaceWire equipment to a SpaceFibre link or network. Developed by the University of Dundee for the European Space Agency (ESA) SpaceFibre is able to operate over fibre-optic and electrical cable and supports data rates of 2 Gbit/s in the near future and up to 5 Gbit/s long-term. Multi-laning improves the data-rate further to well over 20 Gbits/s. This paper details the current state of SpaceFibre which is now in the process of formal standardisation by the European Cooperation for Space Standardization (ECSS). It describes the SpaceFibre IP core being developed for ESA. The design of a SpaceFibre demonstration board is introduced and available SpaceFibre test and development equipment is described. The way in which several SpaceWire links can be concentrated over a single SpaceFibre link will be explained.

Precession of the Earth as the Cause of Geomagnetism: Experiments lend support to the proposal that precessional torques drive the earth's dynamo.

PubMed

Malkus, W V

1968-04-19

I have proposed that the precessional torques acting on the earth can sustain a turbulent hydromagnetic flow in the molten core. A gross balance of the Coriolis force, the Lorentz force, and the precessional force in the core fluid provided estimates of the fluid velocity and the interior magnetic field characteristic of such flow. Then these numbers and a balance of the processes responsible for the decay and regeneration of the magnetic field provided an estimate of the magnetic field external to the core. This external field is in keeping with the observations, but its value is dependent upon the speculative value for the electrical conductivity of core material. The proposal that turbulent flow due to precession can occur in the core was tested in a study of nonmagnetic laboratory flows induced by the steady precession of fluid-filled rotating spheroids. It was found that these flows exhibit both small wavelike instabilities and violent finite-amplitude instability to turbulent motion above critical values of the precession rate. The observed critical parameters indicate that a laminar flow in the core, due to the earth's precession, would have weak hydrodynamic instabilities at most, but that finite-amplitude hydromagnetic instability could lead to fully turbulent flow.

Determination of mass accumulation rates and sediment radionuclide inventories in the deep Black Sea

NASA Astrophysics Data System (ADS)

Buesseler, Ken O.; Benitez, Claudia R.

1994-11-01

Accumulation rates were determined from a detailed profile of 210Pb excess in the top 3 cm of a box core from the deep waters of the western Black Sea. The data suggest a mass accumulation rate (MAR) of 69 ± 3g m -2y -1, less than half the MAR determined by varve counting. It is concluded that recognizable laminae couplets are not formed annually in these sediments. Further support for this conclusion is provided by the well documented fallout peaks of 239,240Pu and 137Cs from atmospheric nuclear weapons testing in the 1960s and the 1986 Chernobyl reactor accident. The 210Pb derived MAR from the top 3 cm is significantly higher than the long-term MAR determined from 14C data, suggesting an increase in accumulation rates within the past 1000-2000 years. The sedimen inventories of 210Pb excess and 239,240Pu match their expected supply, whereas most of the fallout 137Cs remains in the water column. The measured increase in 226Ra inventory in the top cm of this core matches the previously observed decrease in water column 226Ra during the past 30 years.

Vortex Structures in the Shock-deformed Armor Steels

NASA Astrophysics Data System (ADS)

Atroshenko, Svetlana; Meshcheryakov, Yuri; Natalia, Naumova

2009-06-01

Several kinds of armor steel were tested under uniaxial strain conditions within impact velocity range from 250 to 400 m/s. Using optical and REM microscopy, the post shocked specimens were studied to reveal the kinematical mechanisms of dynamic deformation at the mesoscale. In all the specimens, the cross-section of specimens was found to be filled with rotational cells of very complex space morphology. Each rotation cell consists of central core of 1-2 μm in diameter and family of petals surrounding the core, so the space configuration of eddy is closely remands a fan of total size 6-7 μm. During the deformation, the petals move around the core providing the vortical motion of rotation as a whole. Dependence of rotational cell density on the strain rate changes non-monotonously, maximum density corresponds to maximum macrohardness and maximum of spall-strength of steel.

Modeling of rapid shutdown in the DIII-D tokamak by core deposition of high-Z material

DOE PAGES

Izzo, Valerie A.; Parks, Paul B.

2017-06-22

MHD modeling of shell-pellet injection for disruption mitigation is carried out under the assumption of idealized delivery of the radiating payload to the core, neglecting the physics of shell ablation. The shell pellet method is designed to produce an inside-out thermal quench in which core thermal heat is radiated while outer flux surfaces remain intact, protecting the divertor from large conducted heat loads. In the simulation, good outer surfaces remain until the thermal quench is nearly complete, and a high radiated energy fraction is achieved. As a result, when the outermost surfaces are destroyed, runaway electron test orbits indicate thatmore » the rate of runaway electron loss is very fast compared with prior massive gas injection simulations, which is attributed to the very different current profile evolution that occurs with central cooling.« less

High-dose amrinone is required to accelerate rewarming from deliberate mild intraoperative hypothermia for neurosurgical procedures.

PubMed

Inoue, Satoki; Kawaguchi, Masahiko; Sakamoto, Takanori; Kitaguchi, Katsuyasu; Furuya, Hitoshi; Sakaki, Toshisuke

2002-07-01

Since the time available to provide the cooling and rewarming is limited during deliberate mild hypothermia, the technique to accelerate the cooling and rewarming rate of core temperature has been studied. Amrinone has been reported to accelerate the cooling rate but not the rewarming rate of core temperature during deliberate mild hypothermia. The failure of amrinone effect on the rewarming rate might be due to an insufficient dose of amrinone during hypothermic conditions. The authors therefore tested whether higher doses of amrinone can accelerate the rewarming rate of core temperature during deliberate mild hypothermia for neurosurgery. After institutional approval and informed consent, 30 patients were randomly assigned to one of three groups. Patients in the control group (n = 10) did not receive amrinone; patients in the AMR 15 group (n = 10) received 15 microg x kg(-1) x min(-1) amrinone with a 1.0-mg/kg loading dose of amrinone at the beginning of cooling; and patients in the ReAMR group (n = 10) received 5 microg x kg(-1) x min(-1) amrinone with 1.0-mg/kg loading and reloading doses of amrinone at the beginning of cooling and rewarming, respectively. Administration of amrinone was started just after the induction of cooling and continued until the end of anesthesia. Anesthesia was maintained with nitrous oxide in oxygen, propofol, and fentanyl. After induction of anesthesia, patients were cooled, and tympanic membrane temperature was maintained at 34.5 degrees C. After completion of the main surgical procedures, patients were actively rewarmed and extubated in the operating room. The cooling and rewarming rates of core temperature were both significantly faster in both amrinone groups than in the control group. During the cooling and rewarming periods, forearm minus fingertip temperature gradient was significantly smaller in both amrinone groups than in the control group. During the rewarming period, heart rate and mean arterial pressure in the AMR 15 group were significantly faster and lower, respectively, than in the control group. Systemic vascular resistance in the AMR 15 group was smaller than in the control group throughout the study; on the other hand, only the value after the start of rewarming in the ReAMR group was smaller than in the control group. Amrinone at an infusion rate of 15 or 5 microg x kg(-1) x min(-1) with a reloading at the beginning of rewarming accelerated the rewarming rate of core temperature during deliberate mild hypothermia. This suggests that high-dose amrinone is required to accelerate rewarming from deliberate mild intraoperative hypothermia for neurosurgical procedures.

Developing a set of consensus indicators to support maternity service quality improvement: using Core Outcome Set methodology including a Delphi process.

PubMed

Bunch, K J; Allin, B; Jolly, M; Hardie, T; Knight, M

2018-05-16

To develop a core metric set to monitor the quality of maternity care. Delphi process followed by a face-to-face consensus meeting. English maternity units. Three representative expert panels: service designers, providers and users. Maternity care metrics judged important by participants. Participants were asked to complete a two-phase Delphi process, scoring metrics from existing local maternity dashboards. A consensus meeting discussed the results and re-scored the metrics. In all, 125 distinct metrics across six domains were identified from existing dashboards. Following the consensus meeting, 14 metrics met the inclusion criteria for the final core set: smoking rate at booking; rate of birth without intervention; caesarean section delivery rate in Robson group 1 women; caesarean section delivery rate in Robson group 2 women; caesarean section delivery rate in Robson group 5 women; third- and fourth-degree tear rate among women delivering vaginally; rate of postpartum haemorrhage of ≥1500 ml; rate of successful vaginal birth after a single previous caesarean section; smoking rate at delivery; proportion of babies born at term with an Apgar score <7 at 5 minutes; proportion of babies born at term admitted to the neonatal intensive care unit; proportion of babies readmitted to hospital at <30 days of age; breastfeeding initiation rate; and breastfeeding rate at 6-8 weeks. Core outcome set methodology can be used to incorporate the views of key stakeholders in developing a core metric set to monitor the quality of care in maternity units, thus enabling improvement. Achieving consensus on core metrics for monitoring the quality of maternity care. © 2018 The Authors. BJOG: An International Journal of Obstetrics and Gynaecology published by John Wiley & Sons Ltd on behalf of Royal College of Obstetricians and Gynaecologists.

Reactor Simulator Testing Overview

NASA Technical Reports Server (NTRS)

Schoenfeld, Michael P.

2013-01-01

Test Objectives Summary: a) Verify operation of the core simulator, the instrumentation & control system, and the ground support gas and vacuum test equipment. b) Examine cooling & heat regeneration performance of the cold trap purification. c) Test the ALIP pump at voltages beyond 120V to see if the targeted mass flow rate of 1.75 kg/s can be obtained in the RxSim. Testing Highlights: a) Gas and vacuum ground support test equipment performed effectively for operations (NaK fill, loop pressurization, and NaK drain). b) Instrumentation & Control system effectively controlled loop temperature and flow rates or pump voltage to targeted settings and ramped within prescribed constraints. It effectively interacted with reactor simulator control model and defaulted back to temperature control mode if the transient fluctuations didn't dampen. c) Cold trap design was able to obtain the targeted cold temperature of 480 K. An outlet temperature of 636 K was obtained which was lower than the predicted 750 K but 156 K higher than the minimum temperature indicating the design provided some heat regeneration. d) ALIP produce a maximum flow rate of 1.53 kg/s at 800 K when operated at 150 V and 53 Hz.

Facesheet Delamination of Composite Sandwich Materials at Cryogenic Temperatures

NASA Technical Reports Server (NTRS)

Gates, Thomas S.; Odegard, Gregory M.; Herring, Helen M.

2003-01-01

The next generation of space transportation vehicles will require advances in lightweight structural materials and related design concepts to meet the increased demands on performance. One potential source for significant structural weight reduction is the replacement of traditional metallic cryogenic fuel tanks with new designs for polymeric matrix composite tanks. These new tank designs may take the form of thin-walled sandwich constructed with lightweight core and composite facesheets. Life-time durability requirements imply the materials must safely carry pressure loads, external structural loads, resist leakage and operate over an extremely wide temperature range. Aside from catastrophic events like tank wall penetration, one of the most likely scenarios for failure of a tank wall of sandwich construction is the permeation of cryogenic fluid into the sandwich core and the subsequent delamination of the sandwich facesheet due to the build-up of excessive internal pressure. The research presented in this paper was undertaken to help understand this specific problem of core to facesheet delamination in cryogenic environments and relate this data to basic mechanical properties. The experimental results presented herein provide data on the strain energy release rate (toughness) of the interface between the facesheet and the core of a composite sandwich subjected to simulated internal pressure. A unique test apparatus and associated test methods are described and the results are presented to highlight the effects of cryogenic temperature on the measured material properties.

Pole-strength of the earth from Magsat and magnetic determination of the core radius

NASA Technical Reports Server (NTRS)

Voorhies, G. V.; Benton, E. R.

1982-01-01

A model based on two days of Magsat data is used to numerically evaluate the unsigned magnetic flux linking the earth's surface, and a comparison of the 16.054 GWb value calculated with values from earlier geomagnetic field models reveals a smooth, monotonic, and recently-accelerating decrease in the earth's pole strength at a 50-year average rate of 8.3 MWb, or 0.052%/year. Hide's (1978) magnetic technique for determining the radius of the earth's electrically-conducting core is tested by (1) extrapolating main field models for 1960 and 1965 downward through the nearly-insulating mantle, and then separately comparing them to equivalent, extrapolated models of Magsat data. The two unsigned fluxes are found to equal the Magsat values at a radius which is within 2% of the core radius; and (2) the 1960 main field and secular variation and acceleration coefficients are used to derive models of 1930, 1940 and 1950. The same core magnetic radius value, within 2% of the seismic value, is obtained. It is concluded that the mantle is a nearly-perfect insulator, while the core is a perfect conductor, on the decade time scale.

OECD MMCI 2-D Core Concrete Interaction (CCI) tests : CCCI-1 test data report-thermalhydraulic results. Rev 0 January 31, 2004.

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

Farmer, M. T.; Lomperski, S.; Aeschlimann, R. W.

The Melt Attack and Coolability Experiments (MACE) program addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. As a follow-on program to MACE, The Melt Coolability and Concrete Interaction Experiments (MCCI) project is conducting reactor material experiments and associated analysis to achieve the following objectives: (1)more » resolve the ex-vessel debris coolability issue through a program that focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests, and (2) address remaining uncertainties related to long-term two-dimensional molten coreconcrete interactions under both wet and dry cavity conditions. Achievement of these two program objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs for future plants. In terms of satisfying these objectives, the Management Board (MB) approved the conduct of two long-term 2-D Core-Concrete Interaction (CCI) experiments designed to provide information in several areas, including: (i) lateral vs. axial power split during dry core-concrete interaction, (ii) integral debris coolability data following late phase flooding, and (iii) data regarding the nature and extent of the cooling transient following breach of the crust formed at the melt-water interface. This data report provides thermal hydraulic test results from the CCI-1 experiment, which was conducted on December 19, 2003. Test specifications for CCI-1 are provided in Table 1-1. This experiment investigated the interaction of a fully oxidized 400 kg PWR core melt, initially containing 8 wt % calcined siliceous concrete, with a specially designed two-dimensional siliceous concrete test section with an initial cross-sectional area of 50 cm x 50 cm. The report begins by providing a summary description of the CCI-1 test apparatus and operating procedures, followed by presentation of the thermal-hydraulic results. The posttest debris examination results will be provided in a subsequent publication. Observations drawn within this report regarding the overall cavity erosion behavior may be subject to revision once the posttest examinations are completed, since these examinations will fully reveal the final cavity shape.« less

Diurnal effects of prior heat stress exposure on sprint and endurance exercise capacity in the heat.

PubMed

Otani, Hidenori; Kaya, Mitsuharu; Tamaki, Akira; Goto, Heita; Goto, Takayuki; Shirato, Minayuki

2018-03-21

Active individuals often perform exercises in the heat following heat stress exposure (HSE) regardless of the time-of-day and its variation in body temperature. However, there is no information concerning the diurnal effects of a rise in body temperature after HSE on subsequent exercise performance in a hot environnment. This study therefore investigated the diurnal effects of prior HSE on both sprint and endurance exercise capacity in the heat. Eight male volunteers completed four trials which included sprint and endurance cycling tests at 30 °C and 50% relative humidity. At first, volunteers completed a 30-min pre-exercise routine (30-PR): a seated rest in a temperate environment in AM (AmR) or PM (PmR) (Rest trials); and a warm water immersion at 40 °C to induce a 1 °C increase in core temperature in AM (AmW) or PM (PmW) (HSE trials). Volunteers subsequently commenced exercise at 0800 h in AmR/AmW and at 1700 h in PmR/PmW. The sprint test determined a 10-sec maximal sprint power at 5 kp. Then, the endurance test was conducted to measure time to exhaustion at 60% peak oxygen uptake. Maximal sprint power was similar between trials (p = 0.787). Time to exhaustion in AmW (mean±SD; 15 ± 8 min) was less than AmR (38 ± 16 min; p < 0.01) and PmR (43 ± 24 min; p < 0.01) but similar with PmW (24 ± 9 min). Core temperature was higher from post 30-PR to 6 min into the endurance test in AmW and PmW than AmR and PmR (p < 0.05) and at post 30-PR and the start of the endurance test in PmR than AmR (p < 0.05). The rate of rise in core temperature during the endurance test was greater in AmR than AmW and PmW (p < 0.05). Mean skin temperature was higher from post 30-PR to 6 min into the endurance test in HSE trials than Rest trials (p < 0.05). Mean body temperature was higher from post 30-PR to 6 min into the endurance test in AmW and PmW than AmR and PmR (p < 0.05) and the start to 6 min into the endurance test in PmR than AmR (p < 0.05). Convective, radiant, dry and evaporative heat losses were greater on HSE trials than on Rest trials (p < 0.001). Heart rate and cutaneous vascular conductance were higher at post 30-PR in HSE trials than Rest trials (p < 0.05). Thermal sensation was higher from post 30-PR to the start of the endurance test in AmW and PmW than AmR and PmR (p < 0.05). Perceived exertion from the start to 6 min into the endurance test was higher in HSE trials than Rest trials (p < 0.05). This study demonstrates that an approximately 1 °C increase in core temperature by prior HSE has the diurnal effects on endurance exercise capacity but not on sprint exercise capacity in the heat. Moreover, prior HSE reduces endurance exercise capacity in AM, but not in PM. This reduction is associated with a large difference in pre-exercise core temperature between AM trials which is caused by a relatively lower body temperature in the morning due to the time-of-day variation and contributes to lengthening the attainment of high core temperature during exercise in AmR.

Energy Efficient Engine core design and performance report

NASA Technical Reports Server (NTRS)

Stearns, E. Marshall

1982-01-01

The Energy Efficient Engine (E3) is a NASA program to develop fuel saving technology for future large transport aircraft engines. Testing of the General Electric E3 core showed that the core component performance and core system performance necessary to meet the program goals can be achieved. The E3 core design and test results are described.

The Impact of Nuclear Reaction Rate Uncertainties on the Evolution of Core-collapse Supernova Progenitors

NASA Astrophysics Data System (ADS)

Fields, C. E.; Timmes, F. X.; Farmer, R.; Petermann, I.; Wolf, William M.; Couch, S. M.

2018-02-01

We explore properties of core-collapse supernova progenitors with respect to the composite uncertainties in the thermonuclear reaction rates by coupling the probability density functions of the reaction rates provided by the STARLIB reaction rate library with MESA stellar models. We evolve 1000 models of 15{M}ȯ from the pre-main sequence to core O-depletion at solar and subsolar metallicities for a total of 2000 Monte Carlo stellar models. For each stellar model, we independently and simultaneously sample 665 thermonuclear reaction rates and use them in a MESA in situ reaction network that follows 127 isotopes from 1H to 64Zn. With this framework we survey the core mass, burning lifetime, composition, and structural properties at five different evolutionary epochs. At each epoch we measure the probability distribution function of the variations of each property and calculate Spearman rank-order correlation coefficients for each sampled reaction rate to identify which reaction rate has the largest impact on the variations on each property. We find that uncertainties in the reaction rates of {}14{{N}}{({{p}},γ )}15{{O}}, triple-α, {}12{{C}}{(α ,γ )}16{{O}}, 12C(12C,p)23Na, 12C(16O, p)27Al, 16O(16O,n)31S, 16O(16O, p)31P, and 16O(16O,α)28Si dominate the variations of the properties surveyed. We find that variations induced by uncertainties in nuclear reaction rates grow with each passing phase of evolution, and at core H-, He-depletion they are of comparable magnitude to the variations induced by choices of mass resolution and network resolution. However, at core C-, Ne-, and O-depletion, the reaction rate uncertainties can dominate the variation, causing uncertainty in various properties of the stellar model in the evolution toward iron core-collapse.

Selective pH-Responsive Core-Sheath Nanofiber Membranes for Chem/Bio/Med Applications: Targeted Delivery of Functional Molecules.

PubMed

Han, Daewoo; Steckl, Andrew J

2017-12-13

Core-sheath fibers using different Eudragit materials were successfully produced, and their controlled multi-pH responses have been demonstrated. Core-sheath fibers made of Eudragit L 100 (EL100) core and Eudragit S 100 (ES100) sheath provide protection and/or controlled release of core material at pH 6 by adjusting the sheath thickness (controlled by the flow rate of source polymer solution). The thickest sheath (∼250 nm) provides the least core release ∼1.25%/h, while the thinnest sheath (∼140 nm) provides much quicker release ∼16.75%/h. Furthermore, switching core and sheath material dramatically altered the pH response. Core-sheath fibers made of ES100 core and EL100 sheath can provide a consistent core release rate, while the sheath release rate becomes higher as the sheath layer becomes thinner. For example, the thinnest sheath (∼120 nm) provides a core and sheath release ratio of 1:2.5, while the thickest sheath (∼200 nm) shows only a ratio of 1:1.7. All core-sheath Eudragit fibers show no noticeable release at pH 5, while they are completely dissolved at pH 7. Extremely high surface area in the porous network of the fiber membranes provides much faster (>30 times) response to external pH changes as compared to that of equivalent cast films.

Replication of Annual Cycles in Mn in Hudson River Cores: Mn Peaks During High Water Flow

NASA Astrophysics Data System (ADS)

Abbott, D. H.; Hutson, D.; Marrero, A. M.; Block, K. A.; Chang, C.; Cai, Y.

2017-12-01

Using the results from an ITRAX, XRF scanner, we previously reported apparent annual cycles in Mn in a single, high sedimentation rate Hudson River core, LWB1-8, taken off Yonkers, NY (Carlson et al., 2016). We replicated these results in three more high sedimentation rate cores and found stratigraphic markers that verify our inferences about the annual nature of the Mn cycles. The three new cores are LWB4-5 taken off Peekskill, NY, and LWB3-44 and LWB3-25, both taken in Haverstraw Bay. The cores are from water depths of 7-9 meters and all have high magnetic susceptibilities (typically > 30 cgs units) in their upper 1 to 2 meters. The high susceptibilities are primarily produced by magnetite from modern industrial combustion. One core, LWB1-8, has reconnaissance Cs dates that verify the annual nature of the cycles. More Cs dates are expected before the meeting. We developed several new methods of verifying the annual nature of our layer counts. The first is looking at the grain size distribution and age of layers with unusually high Mn peaks. Peaks in Si, Ni and Ti and peaks in percentage of coarse material typically accompany the peaks in Mn. Some are visible as yellow sandy layers. The five highest peaks in Mn in LWB1-8 have layer counted ages that correspond (within 1 year in the top meter and within 2 years in the bottom meter) to 1996, 1948, 1913, 1857 and 1790. The latter three events are the three largest historical spring freshets on the Hudson. 1996 is a year of unusually high flow rate during the spring freshet. Based on our work and previous work on Mn cycling in rivers, we infer that the peaks in Mn are produced by extreme erosional events that erode sediment and release pore water Mn into the water column. The other methods of testing our chronology involve marine storms that increase Ca and Sr and a search for fragments of the Peekskill meteorite that fell in October 1992. More information on the latter will be available by the meeting.

False Operation of Static Random Access Memory Cells under Alternating Current Power Supply Voltage Variation

NASA Astrophysics Data System (ADS)

Sawada, Takuya; Takata, Hidehiro; Nii, Koji; Nagata, Makoto

2013-04-01

Static random access memory (SRAM) cores exhibit susceptibility against power supply voltage variation. False operation is investigated among SRAM cells under sinusoidal voltage variation on power lines introduced by direct RF power injection. A standard SRAM core of 16 kbyte in a 90 nm 1.5 V technology is diagnosed with built-in self test and on-die noise monitor techniques. The sensitivity of bit error rate is shown to be high against the frequency of injected voltage variation, while it is not greatly influenced by the difference in frequency and phase against SRAM clocking. It is also observed that the distribution of false bits is substantially random in a cell array.

Degradation of Si/Ge core/shell nanowire heterostructures during lithiation and delithiation at 0.8 and 20 A g −1

DOE PAGES

Kim, Dongheun; Li, Nan; Sheehan, Chris J.; ...

2018-01-01

The charging rate-dependent degradation of lithium ion battery anodes based on Si/Ge core/shell nanowire heterostructure was observed. Si/Ge core/shell structure was preserved at the charging rate of 0.8 A g −1 . On the other hand, compositional intermixing and loss of Si occurs at the charging rate of 20 A g −1 .

Degradation of Si/Ge core/shell nanowire heterostructures during lithiation and delithiation at 0.8 and 20 A g −1

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

Kim, Dongheun; Li, Nan; Sheehan, Chris J.

The charging rate-dependent degradation of lithium ion battery anodes based on Si/Ge core/shell nanowire heterostructure was observed. Si/Ge core/shell structure was preserved at the charging rate of 0.8 A g −1 . On the other hand, compositional intermixing and loss of Si occurs at the charging rate of 20 A g −1 .

Torque Balances on the Taylor Cylinders in the Geomagnetic Data Assimilation

NASA Technical Reports Server (NTRS)

Kuang, Weijia; Tangborn, Andrew

2004-01-01

In this presentation we report on our continuing effort in geomagnetic data assimilation, aiming at understanding and predicting geomagnetic secular variation on decadal time scales. In particular, we focus on the effect of the torque balances on the cylindrical surfaces in the core co-axial with the Earth's rotation axis (the Taylor cylinders) on the time evolution of assimilated solutions. We use our MoSST core dynamics,model and observed geomagnetic field at the Earth's surface derived via Comprehensive Field Model (CFM) for the geomagnetic data assimilation. In our earlier studies, a model solution is selected randomly from our numerical database. It is then assimilated with the observations such that the poloidal field possesses the same field tomography on the core-mantel boundary (CMB) continued downward from surface observations. This tomography change is assumed to be effective through out the outer core. While this approach allows rapid convergence between model solutions and the observations, it also generates sevee numerical instabilities: the delicate balance between weak fluid inertia and the magnetic torques on the Taylor cylinders are completely altered. Consequently, the assimilated solution diverges quickly (in approximately 10% of the magnetic free-decay time in the core). To improve the assimilation, we propose a partial penetration of the assimilation from the CMB: The full-scale modification at the CMB decreases linearly and vanish at an interior radius r(sub a). We shall examine from our assimilation tests possible relationships between the convergence rate of the model solutions to observations and the cut-off radius r(sub a). A better assimilation shall serve our nudging tests in near future.

Torque Balances on the Taylor Cylinders in the Geomagnetic Data Assimilation

NASA Astrophysics Data System (ADS)

Kuang, W.; Tangborn, A.

2004-05-01

In this presentation we report on our continuing effort in geomagnetic data assimilation, aiming at understanding and predicting geomagnetic secular variation on decadal time scales. In particular, we focus on the effect of the torque balances on the cylindrical surfaces in the core co-axial with the Earth's rotation axis (the Taylor cylinders) on the time evolution of assimilated solutions. We use our MoSST core dynamics model and observed geomagnetic field at the Earth's surface derived via Comprehensive Field Model (CFM) for the geomagnetic data assimilation. In our earlier studies, a model solution is selected randomly from our numerical database. It is then assimilated with the observations such that the poloidal field possesses the same field tomography on the core-mantel boundary (CMB) continued downward from surface observations. This tomography change is assumed to be effective through out the outer core. While this approach allows rapid convergence between model solutions and the observations, it also generates sever numerical instabilities: the delicate balance between weak fluid inertia and the magnetic torques on the Taylor cylinders are completely altered. Consequently, the assimilated solution diverges quickly (in approximately 10% of the magnetic free-decay time in the core). To improve the assimilation, we propose a partial penetration of the assimilation from the CMB: The full-scale modification at the CMB decreases linearly and vanish at an interior radius ra. We shall examine from our assimilation tests possible relationships between the convergence rate of the model solutions to observations and the cut-off radius ra. A better assimilation shall serve our nudging tests in near future.

Emotional exhaustion and cognitive performance in apparently healthy teachers: a longitudinal multi-source study.

PubMed

Feuerhahn, Nicolas; Stamov-Roßnagel, Christian; Wolfram, Maren; Bellingrath, Silja; Kudielka, Brigitte M

2013-10-01

We investigate how emotional exhaustion (EE), the core component of burnout, relates to cognitive performance, job performance and health. Cognitive performance was assessed by self-rated cognitive stress symptoms, self-rated and peer-rated cognitive impairments in everyday tasks and a neuropsychological test of learning and memory (LGT-3); job performance and physical health were gauged by self-reports. Cross-sectional linear regression analyses in a sample of 100 teachers confirm that EE is negatively related to cognitive performance as assessed by self-rating and peer-rating as well as neuropsychological testing (all p < .05). Longitudinal linear regression analyses confirm similar trends (p < .10) for self-rated and peer-rated cognitive performance. Executive control deficits might explain impaired cognitive performance in EE. In longitudinal analyses, EE also significantly predicts physical health. Contrary to our expectations, EE does not affect job performance. When reversed causation is tested, none of the outcome variables at Time 1 predict EE at Time 2. This speaks against cognitive dysfunctioning serving as a vulnerability factor for exhaustion. In sum, results underpin the negative consequences of EE for cognitive performance and health, which are relevant for individuals and organizations alike. In this way, findings might contribute to the understanding of the burnout syndrome. Copyright © 2012 John Wiley & Sons, Ltd.

What is the correlation of in vivo wear and damage patterns with in vitro TDR motion response?

PubMed Central

Kurtz, Steven M.; Patwardhan, Avinash; MacDonald, Daniel; Ciccarelli, Lauren; van Ooij, André; Lorenz, Mark; Zindrick, Michael; O’Leary, Patrick; Isaza, Jorge; Ross, Raymond

2008-01-01

Background Context Total disc replacements (TDRs) have been used to reduce pain and preserve motion. However, the comparison of polyethylene wear following long-term implantation to those tested using an in vitro model had not yet been investigated. Purpose The purpose of this study was to correlate wear and damage patterns in retrieved TDRs with motion patterns observed in a clinically validated in vitro lumbar spine model. We also sought to determine whether one-sided wear and motion patterns were associated with greater in vivo wear. Study Design This two-part study combined the evaluation of retrieved total disc replacements with a biomechanical study using human lumbar spines. Patient Sample 38 CHARITÉ lumbar artificial discs were retrieved from 32 patients (24 female, 75%) after 7.3 years average implantation (range: 1.8 to 16.1y). The components were implanted at L2/L3 (n=1), L3/L4 (n=2), L4/L5 (n=20), and L5/S1 (n=15). All the implants were removed due to intractable back pain and/or facet degeneration. In addition, they were removed due to subsidence (n=10), anterior migration (n=3), core dislocation (n=2), lateral subluxation (n=1), endplate loosening (n = 2), and osteolysis (n=1). In parallel, 7 new implants were evaluated at L4-L5 and 13 implants at L5-S1 in an in vitro lumbar spine model. Outcome Measures Retrieval analysis included evaluation of clinical data, dimensional measurements and assessment of the extent and severity of PE surface damage mechanisms. In vitro testing involved the observation of motion patterns during physiological loading. Methods For the retrievals, each side of the PE core was independently analyzed at the rim and dome for the presence of machining marks, wear, and fracture. 35 cores were further analyzed using MicroCT to determine whether the wear was one-sided, or symmetrically distributed. For the in vitro study the new implants were tested under physiologic loads (flexion-extension with a compressive follower preload) using a validated cadaveric lumbar spine model. The center of the prosthesis was 2 mm posterior to the mid-point of the vertebral body endplate in mid-sagittal plane. Motion patterns of the in vitro-tested implants were tracked using sequential video-flouroscopy. Results Substantial variability was observed in the wear patterns of the retrievals. 15/35 retrieved cores (43%) displayed one-sided wear patterns. The median dome penetration was 0.2 mm (range: 0.06 to 0.9 mm) and the median penetration rate was 0.04 mm/y (range: 0.01 to 0.2 mm/y). No significant difference in penetration or penetration rate was observed between retrievals with one-sided and symmetric wear patterns (p >0.05). Significant correlations were observed between implantation time and penetration (rho = 0.46, p = 0.004) and penetration rate (rho = −0.48, p = 0.003). In the in vitro study, there was clear visual evidence of motion at both articulations in 8/20 implantations. In additional 8/20 cases, there was some evidence of motion at both articulations; however, the predominant motion occurred at the top articulation. In 4/20 implantations motion could be visually detected only at the top articulation. Core entrapment and pinching was observed in 7/20 cases as the segment was extended, and was associated with visual evidence of core bending or deformation in 5/20 cases. PMID:18317190

Identifying Core Concepts of Cybersecurity: Results of Two Delphi Processes

ERIC Educational Resources Information Center

Parekh, Geet; DeLatte, David; Herman, Geoffrey L.; Oliva, Linda; Phatak, Dhananjay; Scheponik, Travis; Sherman, Alan T.

2018-01-01

This paper presents and analyzes results of two Delphi processes that polled cybersecurity experts to rate cybersecurity topics based on importance, difficulty, and timelessness. These ratings can be used to identify core concepts--cross-cutting ideas that connect knowledge in the discipline. The first Delphi process identified core concepts that…

76 FR 63910 - Notice of Availability for Exclusive, Non-Exclusive, or Partially-Exclusive Licensing of an...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-14

..., or Partially-Exclusive Licensing of an Invention Concerning Method for Estimating Core Body... Serial No. 61/572,677, entitled ``Method for Estimating Core Body Temperature from Heart Rate,'' filed on... core temperature from heart rate. The invention further relates to a method of determining impending...

Count every newborn; a measurement improvement roadmap for coverage data.

PubMed

Moxon, Sarah G; Ruysen, Harriet; Kerber, Kate J; Amouzou, Agbessi; Fournier, Suzanne; Grove, John; Moran, Allisyn C; Vaz, Lara M E; Blencowe, Hannah; Conroy, Niall; Gülmezoglu, A; Vogel, Joshua P; Rawlins, Barbara; Sayed, Rubayet; Hill, Kathleen; Vivio, Donna; Qazi, Shamim A; Sitrin, Deborah; Seale, Anna C; Wall, Steve; Jacobs, Troy; Ruiz Peláez, Juan; Guenther, Tanya; Coffey, Patricia S; Dawson, Penny; Marchant, Tanya; Waiswa, Peter; Deorari, Ashok; Enweronu-Laryea, Christabel; Arifeen, Shams; Lee, Anne C C; Mathai, Matthews; Lawn, Joy E

2015-01-01

The Every Newborn Action Plan (ENAP), launched in 2014, aims to end preventable newborn deaths and stillbirths, with national targets of ≤12 neonatal deaths per 1000 live births and ≤12 stillbirths per 1000 total births by 2030. This requires ambitious improvement of the data on care at birth and of small and sick newborns, particularly to track coverage, quality and equity. In a multistage process, a matrix of 70 indicators were assessed by the Every Newborn steering group. Indicators were graded based on their availability and importance to ENAP, resulting in 10 core and 10 additional indicators. A consultation process was undertaken to assess the status of each ENAP core indicator definition, data availability and measurement feasibility. Coverage indicators for the specific ENAP treatment interventions were assigned task teams and given priority as they were identified as requiring the most technical work. Consultations were held throughout. ENAP published 10 core indicators plus 10 additional indicators. Three core impact indicators (neonatal mortality rate, maternal mortality ratio, stillbirth rate) are well defined, with future efforts needed to focus on improving data quantity and quality. Three core indicators on coverage of care for all mothers and newborns (intrapartum/skilled birth attendance, early postnatal care, essential newborn care) have defined contact points, but gaps exist in measuring content and quality of the interventions. Four core (antenatal corticosteroids, neonatal resuscitation, treatment of serious neonatal infections, kangaroo mother care) and one additional coverage indicator for newborns at risk or with complications (chlorhexidine cord cleansing) lack indicator definitions or data, especially for denominators (population in need). To address these gaps, feasible coverage indicator definitions are presented for validity testing. Measurable process indicators to help monitor health service readiness are also presented. A major measurement gap exists to monitor care of small and sick babies, yet signal functions could be tracked similarly to emergency obstetric care. The ENAP Measurement Improvement Roadmap (2015-2020) outlines tools to be developed (e.g., improved birth and death registration, audit, and minimum perinatal dataset) and actions to test, validate and institutionalise proposed coverage indicators. The roadmap presents a unique opportunity to strengthen routine health information systems, crosslinking these data with civil registration and vital statistics and population-based surveys. Real measurement change requires intentional transfer of leadership to countries with the greatest disease burden and will be achieved by working with centres of excellence and existing networks.

Nitrogen fluxes across hydrogeomorphic zones in coastal deltaic floodplain using flow-through technique

NASA Astrophysics Data System (ADS)

Li, S.; Twilley, R.; Christensen, A.

2017-12-01

Coastal floodplain deltas are the region of continental margins of major river basins that can remove excess nitrogen before entering the coastal ocean. We propose that the processing of nitrogen in active deltaic wetlands varies with soil organic content in response to different hydrogeomorphic zones. Continuous flow-through core system was used to incubate sediment cores from supratidal, intertidal, and subtidal hydrogeomorphic zones along a chronosequence in Wax Lake Delta during summer of 2017. Ambient water from Wax Lake Outlet was continuously pumped through sealed cores to estimate fluxes of inorganic nitrogen and phosphorus across the sediment-water interface by calculating the difference between inflow and outflow concentrations. The average respiration rate of sediment cores from intertidal zone was about 1.5 g m-2 d-1 while the rate in supratidal zone was more than doubled to 3.7 g m-2 d-1. Under the constant inflow concentration of nitrate (about 107.1 umol/L), sediment cores in supratidal zone exhibited greater NO3- uptake (1329.7 umol m-2 h-1) and N2 release (499.0 umol N m-2 h-1) than that in intertidal zone (421.5 umol m-2 h-1 of NO3- uptake and 67.6 umol N m-2 h-1 of N2 flux respectively). These results indicate greater rate of net denitrification in supratidal zone than intertidal zone in the older chronosequence of the active delta (which formed approximately in 1980). Also, lower NH4 flux (mean 70.0 umol m-2 h-1) from sediment to water column in supratidal zone together with higher NO2- flux (mean 94.2 umol m-2 h-1) illustrated strong signal of nitrification. In conclusion, sediment cores at the intertidal zone helped to remove 12% of NO3- from the water column while cores at supratidal zone removed 35% of NO3-. Based on the correlation between NO3- and N2 fluxes, about 60% of NO3- removed could be converted to N2 under sediment organic concentrations of about 12%. Comparisons of NO3 removal and conversion to N2 by denitrification will be compared along the chronosequence to test the effects of shifts from mineral to organic soils as active deltas develop at the mouths of major river basins.

Operational performance of the three bean salad control algorithm on the ACRR

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

Ball, R.M.; Madaras, J.J.; Trowbridge, F.R. Jr.

Experimental tests on the Annular Core Research Reactor have confirmed that the Three-Bean-Salad'' control algorithm based on the Pontryagin maximum principle can change the power of a nuclear reactor many decades with a very fast startup rate and minimal overshoot. The paper describes the results of simulations and operations up to 25 MW and 87 decades per minute.

Operational performance of the three bean salad control algorithm on the ACRR

NASA Astrophysics Data System (ADS)

Ball, Russell M.; Madaras, John J.; Trowbridge, F. Ray; Talley, Darren G.; Parma, Edward J.

1991-01-01

Experimental tests on the Annular Core Research Reactor have confirmed that the ``Three-Bean-Salad'' control algorithm based on the Pontryagin maximum principle can change the power of a nuclear reactor many decades with a very fast startup rate and minimal overshoot. The paper describes the results of simulations and operations up to 25 MW and 87 decades per minute.

How Do the Different Components of Episodic Memory Develop? Role of Executive Functions and Short-Term Feature-Binding Abilities

ERIC Educational Resources Information Center

Picard, Laurence; Cousin, Sidonie; Guillery-Girard, Berenere; Eustache, Francis; Piolino, Pascale

2012-01-01

This study investigated the development of all 3 components of episodic memory (EM), as defined by Tulving, namely, core factual content, spatial context, and temporal context. To this end, a novel, ecologically valid test was administered to 109 participants aged 4-16 years. Results showed that each EM component develops at a different rate.…

Column Testing and 1D Reactive Transport Modeling to Evaluate Uranium Plume Persistence Processes

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

Johnson, Raymond H.; Morrison, Stan; Morris, Sarah

Motivation for Study: Natural flushing of contaminants at various U.S. Department of Energy Office of Legacy Management sites is not proceeding as quickly as predicted (plume persistence) Objectives: Help determine natural flushing rates using column tests. Use 1D reactive transport modeling to better understand the major processes that are creating plume persistence Approach: Core samples from under a former mill tailings area Tailings have been removed. Column leaching using lab-prepared water similar to nearby Gunnison River water. 1D reactive transport modeling to evaluate processes

JAERI instrumented spool piece performance in two-phase flow

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

Colson, J.B.; Gilbert, J.V.

1979-01-01

Instrumented spool pieces to be installed in horizontal piping on the Cylindrical Core Test Facility (CCTF) at the Japanese Atomic Energy Institute (JAERI) have been designed and tested. The instrumented spool pieces will provide measurements from which mass flow rates can be computed. The primary instruments included in the spool pieces are a full-flow turbine, a full-flow perforated drag plate, and a low energy three-beam photon densitometer. Secondary instruments are provided to measured absolute pressure, fluid temperature, and differential pressure across the full-flow perforated drag plate.

Neighborhood sampling: how many streets must an auditor walk?

PubMed

McMillan, Tracy E; Cubbin, Catherine; Parmenter, Barbara; Medina, Ashley V; Lee, Rebecca E

2010-03-12

This study tested the representativeness of four street segment sampling protocols using the Pedestrian Environment Data Scan (PEDS) in eleven neighborhoods surrounding public housing developments in Houston, TX. The following four street segment sampling protocols were used (1) all segments, both residential and arterial, contained within the 400 meter radius buffer from the center point of the housing development (the core) were compared with all segments contained between the 400 meter radius buffer and the 800 meter radius buffer (the ring); all residential segments in the core were compared with (2) 75% (3) 50% and (4) 25% samples of randomly selected residential street segments in the core. Analyses were conducted on five key variables: sidewalk presence; ratings of attractiveness and safety for walking; connectivity; and number of traffic lanes. Some differences were found when comparing all street segments, both residential and arterial, in the core to the ring. Findings suggested that sampling 25% of residential street segments within the 400 m radius of a residence sufficiently represents the pedestrian built environment. Conclusions support more cost effective environmental data collection for physical activity research.

Neighborhood sampling: how many streets must an auditor walk?

PubMed Central

2010-01-01

This study tested the representativeness of four street segment sampling protocols using the Pedestrian Environment Data Scan (PEDS) in eleven neighborhoods surrounding public housing developments in Houston, TX. The following four street segment sampling protocols were used (1) all segments, both residential and arterial, contained within the 400 meter radius buffer from the center point of the housing development (the core) were compared with all segments contained between the 400 meter radius buffer and the 800 meter radius buffer (the ring); all residential segments in the core were compared with (2) 75% (3) 50% and (4) 25% samples of randomly selected residential street segments in the core. Analyses were conducted on five key variables: sidewalk presence; ratings of attractiveness and safety for walking; connectivity; and number of traffic lanes. Some differences were found when comparing all street segments, both residential and arterial, in the core to the ring. Findings suggested that sampling 25% of residential street segments within the 400 m radius of a residence sufficiently represents the pedestrian built environment. Conclusions support more cost effective environmental data collection for physical activity research. PMID:20226052

Tracking recent climate and anthropogenic change in Central America in sediments form the lower fan of the Rio Yaqui, Gulf of California, Mexico

NASA Astrophysics Data System (ADS)

Aiello, I. W.; Ravelo, A. C.; Moraes, R.; Swarzenski, P. W.

2015-12-01

We report the results of preliminary sedimentologic analyses of a ~3.3m long piston core (P13) collected in the lower fan of the Rio Yaqui (Guaymas Basin, Gulf of California; depth, 1859m) by UNAM's (Universidad Nacional Autónoma de México) research ship El Puma in 2014. The core was collected to test the potential for high-resolution reconstructions of basin-scale paleoclimate in the Pacific and the Mesoamerican region. Shipboard and post-cruise analyses include magnetic susceptibility (MS), smear slide counts and laser diffraction particle size analysis. The core is being analyzed for X-Ray Fluorescence (XRF) and color reflectance, and a 210Pb age model is being constructed. Preliminary results show that Rio Yaqui lower fan sediment differs significantly from that in the Guaymas Basin, which is dominantly diatom ooze. The lower ~2m of core P13 show prominent alternations (~10-20cm) between very-fine-grained, clay intervals characterized by higher MS and mixed diatom and clay intervals, with coarser grain size and lower MS values. In contrast, the upper ~1m has distinctive high MS sand turbidites alternating with diatom-rich layers. Previous core studies from nearby ODP Leg 64 site show sedimentation rates of ~1.2 m/ka; as these sites are further away from the Yaqui delta the sedimentation rates for core P13 should be higher possibly recording only the last few hundred years of sedimentation. Clay/diatom cycles in the lower part of the core could record decadal- or ENSO-scale wet/aridity cycles in the Sonoran Mainland. Conversely, the coarser siliciclastic intervals and the diatom layers in the upper part of the core could reflect the last few decades of land usage in the watershed of the Rio Yaqui, the most important river in the state of Sonora, Mexico. These include large modifications to the river's hydrography (e.g. construction of dams and aqueducts), rapidly expanding mass agricultural practices in the region, and increased eutrophication in the Gulf.

Detectability and Uncertainties of the Supernova Relic Neutrino Background

NASA Astrophysics Data System (ADS)

Nakazato, Ken'ichiro; Mochida, Eri; Niino, Yuu; Suzuki, Hideyuki

The spectrum of the supernova relic neutrino (SRN) background from past stellar core collapses is calculated and its detectability at SK-Gd (Super-Kamiokande experiment with gadolinium-loaded water) is investigated. Several uncertainties on the flux of SRNs are considered. The core collapse rate at each redshift depends on the cosmic star formation rate, initial mass function and mass range of progenitors that end with a core collapse. The shock revival time is introduced as a parameter that should depend on the still unknown explosion mechanism of core collapse supernovae. Furthermore, since the neutrino luminosity of black-hole-forming failed supernovae is higher than that of ordinary supernovae, their contribution to SRNs is quantitatively estimated. Assuming the mass and metallicity ranges of their progenitors, the redshift dependence of the black hole formation rate is considered on the basis of the metallicity evolution of galaxies. As a result, it is found that the expected event rate of SRNs is comparable with other backgrounds at SK-Gd. Therefore, the required observation time to detect SRNs at SK-Gd depends strongly on the core collapse rate and it is 10-300 years.

Performance evaluation of a direct-conversion flat-panel detector system in imaging and quality assurance for a high-dose-rate 192Ir source

NASA Astrophysics Data System (ADS)

Miyahara, Yoshinori; Hara, Yuki; Nakashima, Hiroto; Nishimura, Tomonori; Itakura, Kanae; Inomata, Taisuke; Kitagaki, Hajime

2018-03-01

In high-dose-rate (HDR) brachytherapy, a direct-conversion flat-panel detector (d-FPD) clearly depicts a 192Ir source without image halation, even under the emission of high-energy gamma rays. However, it was unknown why iridium is visible when using a d-FPD. The purpose of this study was to clarify the reasons for visibility of the source core based on physical imaging characteristics, including the modulation transfer functions (MTF), noise power spectral (NPS), contrast transfer functions, and linearity of d-FPD to high-energy gamma rays. The acquired data included: x-rays, [X]; gamma rays, [γ] dual rays (X  +  γ), [D], and subtracted data for depicting the source ([D]  -  [γ]). In the quality assurance (QA) test for the positional accuracy of a source core, the coordinates of each dwelling point were compared between the planned and actual source core positions using a CT/MR-compatible ovoid applicator and a Fletcher-Williamson applicator. The profile curves of [X] and ([D]  -  [γ]) matched well on MTF and NPS. The contrast resolutions of [D] and [X] were equivalent. A strongly positive linear correlation was found between the output data of [γ] and source strength (r 2  >  0.99). With regard to the accuracy of the source core position, the largest coordinate difference (3D distance) was noted at the maximum curvature of the CT/MR-compatible ovoid and Fletcher-Williamson applicators, showing 1.74  ±  0.02 mm and 1.01  ±  0.01 mm, respectively. A d-FPD system provides high-quality images of a source, even when high-energy gamma rays are emitted to the detector, and positional accuracy tests with clinical applicators are useful in identifying source positions (source movements) within the applicator for QA.

210Pb and 137Cs as chronometers for salt marsh accretion in the Venice Lagoon - links to flooding frequency and climate change.

PubMed

Bellucci, L G; Frignani, M; Cochran, J K; Albertazzi, S; Zaggia, L; Cecconi, G; Hopkins, H

2007-01-01

Five salt marsh sediment cores from different parts of the Venice Lagoon were studied to determine their depositional history and its relationship with the environmental changes occurred during the past approximately 100 years. X-radiographs of the cores show no disturbance related to particle mixing. Accretion rates were calculated using a constant flux model applied to excess (210)Pb distributions in the cores. The record of (137)Cs fluxes to the sites, determined from (137)Cs profiles and the (210)Pb chronologies, shows inputs from the global fallout of (137)Cs in the late 1950s to early 1960s and the Chernobyl accident in 1986. Average accretion rates in the cores are comparable to the long-term average rate of mean sea level rise in the Venice Lagoon ( approximately 0.25 cm y(-1)) except for a core collected in a marsh presumably affected by inputs from the Dese River. Short-term variations in accretion rate are correlated with the cumulative frequency of flooding, as determined by records of Acqua Alta, in four of the five cores, suggesting that variations in the phenomena causing flooding (such as wind patterns, storm frequency and NAO) are short-term driving forces for variations in marsh accretion rate.

Enhanced capabilities of separation in Sequential Injection Chromatography--fused-core particle column and its comparison with narrow-bore monolithic column.

PubMed

Chocholouš, Petr; Kosařová, Lucie; Satínský, Dalibor; Sklenářová, Hana; Solich, Petr

2011-08-15

In the Sequential Injection Chromatography (SIC) only monolithic columns for chromatographic separations have been used so far. This article presents the first use of fused-core particle packed column in an attempt to extend of the chromatographic capabilities of the SIC system. A new fused-core particle column (2.7 μm) Ascentis(®) Express C18 (Supelco™ Analytical) 30 mm × 4.6 mm brings high separation efficiency within flow rates and pressures comparable to monolithic column Chromolith(®) Performance RP-18e 100-3 (Merck(®)) 100 mm × 3 mm. Both columns matches the conditions of the commercially produced SIC system - SIChrom™ (8-port high-pressure selection valve and medium-pressure Sapphire™ syringe pump with 4 mL reservoir - maximal work pressure 1000 PSI) (FIAlab(®), USA). The system was tested by the separation of four estrogens with similar structure and an internal standard - ethylparaben. The mobile phase composed of acetonitrile/water (40/60 (v/v)) was pumped isocratic at flow rate 0.48 mL min(-1). Spectrophotometric detection was performed at wavelength of 225 nm and injected volume of sample solutions was 10 μL. The chromatographic characteristics of both columns were compared. Obtained results and conclusions have shown that both fused-core particle column and longer narrow shaped monolithic column bring benefits into the SIC method. Copyright © 2011 Elsevier B.V. All rights reserved.

Modelling the carbonation of cementitious matrixes by means of the unreacted-core model, UR-CORE

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

Castellote, M.; Andrade, C.

This paper presents a model for the carbonation of cementitious matrixes (UR-CORE). The model is based on the principles of the 'unreacted-core' systems, typical of chemical engineering processes, in which the reacted product remains in the solid as a layer of inert ash, adapted for the specific case of carbonation. Development of the model has been undertaken in three steps: 1) Establishment of the controlling step in the global carbonation rate, by using data of fractional conversion of different phases of the cementitious matrixes, obtained by the authors through neutron diffraction data experiments, and reported in [M. Castellote, C. Andrade,more » X. Turrillas, J. Campo, G. Cuello, Accelerated carbonation of cement pastes in situ monitored by neutron diffraction, Cem. Concr. Res. (2008), doi:10.1016/j.cemconres.2008.07.002]. 2) Then, the model has been adapted and applied to the cementitious materials using different concentrations of CO{sub 2}, with the introduction of the needed assumptions and factors. 3) Finally, the model has been validated with laboratory data at different concentrations (taken from literature) and for long term natural exposure of concretes. As a result, the model seems to be reliable enough to be applied to cementitious materials, being able to extrapolate the results from accelerated tests in any conditions to predict the rate of carbonation in natural exposure, being restricted, at present stage, to conditions with a constant relative humidity.« less

Hydro-geophysical responses to the injection of CO2 in core plugs of Berea sandstone

NASA Astrophysics Data System (ADS)

Song, I.; Park, K. G.

2017-12-01

We have built a laboratory-scale core flooding system to measure the relative permeability of a core sample and the acoustic response to the CO2 saturation degree at in situ condition of pressure and temperature down to a few kilometer depths. The system consisted of an acoustic velocity core holder (AVC model from the Core Laboratories) between upstream where CO2 and H2O were injected separately and downstream where the mixed fluids came out of a core sample. Core samples with 4 cm in diameter and 5 cm in length of Berea sandstone were in turn placed in the core holder for confining and axial pressures. The flooding operations of the multiphase fluids were conducted through the sample at 40ºC in temperature and 8 MPa in backpressure. CO2 and H2O in the physical condition were injected separately into a sample at constant rate with various ratios. The two phases were mixed during flowing through the sample. The mixed fluids out of the sample were separated again by their different densities in a chamber equipped with a level gauge of the interface. From the level change of the water in the separator, we measured the volume of water coming out of the sample for each test with a constant ratio of the injection rates. Then it was possible to calculate the saturation degree of CO2 from the difference between input volume and output volume of water. The differential pressure between upstream and downstream was directly measured to calculate the relative permeability as a function of the CO2 saturation degree. We also conducted ultrasonic measurements using piezoelectric sensors on the end plugs. An electric pulse was given to a sensor on one end of sample, and then ultrasonic waves were recorded from the other end. The various ratios of injection rate of CO2 and H2O into Berea sandstone yielded a range of 0.1-0.7 in CO2 saturation degree. The relative permeability was obtained at the condition of steady-state flow for given stages from the velocity of each phase and the pressure gradient. The arrival time of P-wave became retarded and its amplitude became smaller as the degree of CO2 saturation increases. However no change was observed in S-wave in both characters. According to our results, time-lapse measurements of P-wave signals can be a monitoring tool of the subsurface migration of CO2, thus of detecting even its leakage.

Dynamical Processes Near the Super Massive Black Hole at the Galactic Center

NASA Astrophysics Data System (ADS)

Antonini, Fabio

2011-01-01

Observations of the stellar environment near the Galactic center provide the strongest empirical evidence for the existence of massive black holes in the Universe. Theoretical models of the Milky Way nuclear star cluster fail to explain numerous properties of such environment, including the presence of very young stars close to the super massive black hole (SMBH) and the more recent discovery of a parsec-scale core in the central distribution of the bright late-type (old) stars. In this thesis we present a theoretical study of dynamical processes near the Galactic center, strongly related to these issues. Using different numerical techniques we explore the close environment of a SMBH as catalyst for stellar collisions and mergers. We study binary stars that remain bound for several revolutions around the SMBH, finding that in the case of highly inclined binaries the Kozai resonance can lead to large periodic oscillations in the internal binary eccentricity and inclination. Collisions and mergers of the binary elements are found to increase significantly for multiple orbits around the SMBH. In collisions involving a low-mass and a high-mass star, the merger product acquires a high core hydrogen abundance from the smaller star, effectively resetting the nuclear evolution clock to a younger age. This process could serve as an important source of young stars at the Galactic center. We then show that a core in the old stars can be naturally explained in a scenario in which the Milky Way nuclear star cluster (NSC) is formed via repeated inspiral of globular clusters into the Galactic center. We present results from a set of N -body simulations of this process, which show that the fundamental properties of the NSC, including its mass, outer density profile and velocity structure, are also reproduced. Chandrasekhar's dynamical friction formula predicts no frictional force on a test body in a low-density core, regardless of its density, due to the absence of stars moving more slowly than the local circular velocity. We have tested this prediction using large-scale N -body experiments. The rate of orbital decay never drops precisely to zero, because stars moving faster than the test body also contribute to the frictional force. When the contribution from the fast-moving stars is included in the expression for the dynamical friction force, and the changes induced by the massive body on the stellar distribution are taken into account, Chandrasekhar's theory is found to reproduce the rate of orbital decay remarkably well. However, this rate is still substantially smaller than the rate predicted by Chandrasekhar's formula in its most widely-used forms, implying longer time scales for inspiral. Motivated by recent observations that suggest a parsec-scale core around the Galactic center SMBH, we investigated the evolution of a population of stellar-mass black holes (BHs) as they spiral in to the center of the Galaxy. After ˜ 10 Gyr, we find that the density of BHs can remain substantially less than the density in stars at all radii; we conclude that it would be unjustified to assume that the spatial distribution of BHs at the Galactic center is well described by steady-state models.

Reactor Simulator Testing

NASA Technical Reports Server (NTRS)

Schoenfeld, Michael P.; Webster, Kenny L.; Pearson, Boise J.

2013-01-01

As part of the Nuclear Systems Office Fission Surface Power Technology Demonstration Unit (TDU) project, a reactor simulator test loop (RxSim) was design & built to perform integrated testing of the TDU components. In particular, the objectives of RxSim testing was to verify the operation of the core simulator, the instrumentation and control system, and the ground support gas and vacuum test equipment. In addition, it was decided to include a thermal test of a cold trap purification design and a pump performance test at pump voltages up to 150 V since the targeted mass flow rate of 1.75 kg/s was not obtained in the RxSim at the originally constrained voltage of 120 V. This paper summarizes RxSim testing. The gas and vacuum ground support test equipment performed effectively in NaK fill, loop pressurization, and NaK drain operations. The instrumentation and control system effectively controlled loop temperature and flow rates or pump voltage to targeted settings. The cold trap design was able to obtain the targeted cold temperature of 480 K. An outlet temperature of 636 K was obtained which was lower than the predicted 750 K but 156 K higher than the cold temperature indicating the design provided some heat regeneration. The annular linear induction pump (ALIP) tested was able to produce a maximum flow rate of 1.53 kg/s at 800 K when operated at 150 V and 53 Hz.

Reactor Simulator Integration and Testing

NASA Technical Reports Server (NTRS)

Schoenfield, M. P.; Webster, K. L.; Pearson, J. B.

2013-01-01

As part of the Nuclear Systems Office Fission Surface Power Technology Demonstration Unit (TDU) project, a reactor simulator (RxSim) test loop was designed and built to perform integrated testing of the TDU components. In particular, the objectives of RxSim testing were to verify the operation of the core simulator, the instrumentation and control system, and the ground support gas and vacuum test equipment. In addition, it was decided to include a thermal test of a cold trap purification design and a pump performance test at pump voltages up to 150 V because the targeted mass flow rate of 1.75 kg/s was not obtained in the RxSim at the originally constrained voltage of 120 V. This Technical Memorandum summarizes RxSim testing. The gas and vacuum ground support test equipment performed effectively in NaK fill, loop pressurization, and NaK drain operations. The instrumentation and control system effectively controlled loop temperature and flow rates or pump voltage to targeted settings. The cold trap design was able to obtain the targeted cold temperature of 480 K. An outlet temperature of 636 K was obtained, which was lower than the predicted 750 K but 156 K higher than the cold temperature, indicating the design provided some heat regeneration. The annular linear induction pump tested was able to produce a maximum flow rate of 1.53 kg/s at 800 K when operated at 150 V and 53 Hz.

Aiming for the stomach and hitting the heart: Dissociable triggers and sources for disgust reactions

PubMed Central

Shenhav, Amitai; Mendes, Wendy Berry

2014-01-01

Disgust reactions can be elicited using stimuli that engender orogastric rejection (e.g., pus and vomit; Core Disgust stimuli), but also using images of bloody injuries or medical procedures (e.g., surgeries; Blood-[Body] Boundary Violation [B-BV] Disgust stimuli). These two types of disgust reaction are believed to be connected by a common evolutionary function of avoiding either food- or blood-borne contaminants. However, reactions to the category of bloody injuries are typically conflated with reactions to the potential pain being experienced by the victim. This may explain why the two forms of ‘disgust,’ though similarly communicated (through self-report and facial expressions) evince different patterns of physiological reactivity. We therefore tested whether the communicative similarities and physiological dissimilarities would hold when markers of potential contamination in the latter category are removed, leaving only painful injuries that lack blood or explicit body-envelope violations. Participants viewed films that depicted imagery associated with (1) core disgust, (2) painful injuries, or (3) neutral scenes while we measured facial, cardiovascular, and gastric reactivity, respectively. Whereas communicative measures (self-report and facial muscles) suggested that participants experienced increased disgust for both core disgust and painful injuries, peripheral physiology dissociated the two: core disgust decreased normal gastric activity and painful-injury disgust decelerated heart rate and increased heart rate variability. These findings suggest that expressions of disgust toward bodily injuries may reflect a fundamentally different affective response than those evoked by core disgust, and that this (cardiovascularly-mediated) response may in fact be more closely tied to pain-perceptions (or empathy) rather than contaminant-laden stimuli. PMID:24219399

The Effect of an Amino Acid Infusion on Central Thermoregulatory Control in Humans

PubMed Central

Nakajima, Yasufumi; Takamata, Akira; Matsukawa, Takashi; Sessler, Daniel I.; Kitamura, Yoshihiro; Ueno, Hiroshi; Tanaka, Yoshifumi; Mizobe, Toshiki

2005-01-01

Background Administration of protein or amino acids enhances thermogenesis, presumably by stimulating oxidative metabolism. However, hyperthermia results even when thermoregulatory responses are intact, suggesting that amino acids also alter central thermoregulatory control. We thus tested the hypothesis that amino acid infusion increases the thermoregulatory setpoint. Methods Nine male volunteers each participated on four study days in randomized order: 1) intravenous amino acids infused at 4 kJ·kg−1·hr−1 for 2.5 h combined with skin-surface warming; 2) amino acid infusion combined with cutaneous cooling; 3) a saline infusion combined with skin-surface warming; and, 4) saline infusion combined with cutaneous cooling. Results Amino acid infusion increased resting core temperature by 0.3 ± 0.1°C (mean ± SD) and oxygen consumption by 18 ± 12%. Furthermore, amino acid infusion increased the calculated core temperature threshold (triggering core temperature at a designated mean-skin temperature of 34°C) for active cutaneous vasodilation by 0.3 ± 0.3°C, for sweating by 0.2 ± 0.2°C, for thermoregulatory vasoconstriction by 0.3 ± 0.3°C, and for thermogenesis by 0.4 ± 0.5°C. Amino acid infusion did not alter the incremental response intensity (i.e., gain) of thermoregulatory defenses. Conclusions Amino acid infusion increased the metabolic rate and resting core temperature. However, amino acids also produced a synchronous increase in all major autonomic thermoregulatory defense thresholds; the increase in core temperature was identical to the setpoint increase — even in a cold environment with amble potential to dissipate heat. In subjects with intact thermoregulatory defenses, amino acid-induced hyperthermia appears to result from an elevated setpoint increase rather than increased metabolic rate per se. PMID:15108979

Thermophysiological responses caused by ballistic bullet-proof vests.

PubMed

Lehmacher, E J; Jansing, P; Küpper, T

2007-01-01

Little data is available concerning the heat stress experienced by members of staff who wear bullet-proof vests in a warm or hot environment. For this reason, knowledge is limited and, consequently, preventative advice on how to avoid heat sickness or hyperthermia is required. Skin and body temperatures, fluid loss and the heart rate of 30 persons (15 test persons versus 15 control persons) were measured in three situations typical of the test participants' job situations. Environmental data (wind velocity, air humidity, air temperature) were measured during the tests as well. Whereas there was a significant increase in skin temperatures, there was no difference in the core body temperatures of both groups. Maximum core body temperature remained well below 38 degrees C in all subjects. Test persons wearing vests showed a fluid loss of 1.1 l on average (non-vest wearers in the control group 1.0 l). There is no increased risk of heat stroke or hyperthermia for employees wearing bullet-proof vests in comparison with employees who do not wear them. Both groups, however, should be advised to ensure an adequate intake of fluid to maintain a healthy body fluid balance when working in hot environments.

Characterizing Facesheet/Core Disbonding in Honeycomb Core Sandwich Structure

NASA Technical Reports Server (NTRS)

Rinker, Martin; Ratcliffe, James G.; Adams, Daniel O.; Krueger, Ronald

2013-01-01

Results are presented from an experimental investigation into facesheet core disbonding in carbon fiber reinforced plastic/Nomex honeycomb sandwich structures using a Single Cantilever Beam test. Specimens with three, six and twelve-ply facesheets were tested. Specimens with different honeycomb cores consisting of four different cell sizes were also tested, in addition to specimens with three different widths. Three different data reduction methods were employed for computing apparent fracture toughness values from the test data, namely an area method, a compliance calibration technique and a modified beam theory method. The compliance calibration and modified beam theory approaches yielded comparable apparent fracture toughness values, which were generally lower than those computed using the area method. Disbonding in the three-ply facesheet specimens took place at the facesheet/core interface and yielded the lowest apparent fracture toughness values. Disbonding in the six and twelve-ply facesheet specimens took place within the core, near to the facesheet/core interface. Specimen width was not found to have a significant effect on apparent fracture toughness. The amount of scatter in the apparent fracture toughness data was found to increase with honeycomb core cell size.

Pretest analysis of natural circulation on the PWR model PACTEL with horizontal steam generators

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

Kervinen, T.; Riikonen, V.; Ritonummi, T.

A new tests facility - parallel channel tests loop (PACTEL)- has been designed and built to simulate the major components and system behavior of pressurized water reactors (PWRs) during postulated small- and medium-break loss-of-coolant accidents. Pretest calculations have been performed for the first test series, and the results of these calculations are being used for planning experiments, for adjusting the data acquisition system, and for choosing the optimal position and type of instrumentation. PACTEL is a volumetrically scaled (1:305) model of the VVER-440 PWR. In all the calculated cases, the natural circulation was found to be effective in removing themore » heat from the core to the steam generator. The loop mass flow rate peaked at 60% mass inventory. The straightening of the loop seals increased the mass flow rate significantly.« less

Building on previous OSL dating techniques for gypsum: a case study from Salt Basin playa, New Mexico and Texas

USGS Publications Warehouse

Mahan, Shannon; Kay, John

2012-01-01

The long term stability and reliability of the luminescence signal for gypsum has not been well documented or systematically measured until just recently. A review of the current literature for luminescence dating of gypsum is compiled here along with original efforts at dating an intact and in-situ bed of selenite gypsum at Salt Basin Playa, New Mexico and Texas. This effort differs from other documented luminescence dating efforts because the gypsum is not powdery or redistributed from its original growth patterns within the playa basin but is instead of a crystalline form. Sixteen ages from eight cores were ultimately produced with seven of the ages coming from rare detrital quartz encased in or with the gypsum crystals while the remaining ages are from the crystalline gypsum. As far as can be ascertained, the quartz was measured separately from the gypsum and no contaminants were noted in any of the aliquots. Some basic and preliminary tests of signal stability were measured and found to be mitigated by lessening of pre-heat protocols. Ages ranged from 8 ka to 10 ka in the shallow cores and 16 ka to 22 ka in the deeper cores. These ages will be useful in determining rates of gypsum growth within a sequence of evaporates which, in turn, will help to better document historic rates of evaporation and thus estimate, with more precision, the corresponding annual evaporation rates.

Degradation of Si/Ge core/shell nanowire heterostructures during lithiation and delithiation at 0.8 and 20 A g-1.

PubMed

Kim, Dongheun; Li, Nan; Sheehan, Chris J; Yoo, Jinkyoung

2018-04-26

Si/Ge core/shell nanowire heterostructures have been expected to provide high energy and power densities for lithium ion battery anodes due to the large capacity of Si and the high electrical and ionic conductivities of Ge. Although the battery anode performances of Si/Ge core/shell nanowire heterostructures have been characterized, the degradation of Si/Ge core/shell nanowire heterostructures has not been thoroughly investigated. Here we report the compositional and structural changes of the Si/Ge core/shell nanowire heterostructure over cycling of lithiation and delithiation at different charging rates. The Si/Ge core/shell nanowire heterostructure holds the core and shell structure at a charging rate of 0.8 A g-1 up to 50 cycles. On the other hand, compositional intermixing and loss of Si occur at a charging rate of 20 A g-1 within 50 cycles. The operation condition-dependent degradation provides a new aspect of materials research for the development of high performance lithium ion battery anodes with a long cycle life.

Behavior of a high-temperature superconducting conductor on a round core cable at current ramp rates as high as 67.8 kA s-1 in background fields of up to 19 T

NASA Astrophysics Data System (ADS)

Michael, P. C.; Bromberg, L.; van der Laan, D. C.; Noyes, P.; Weijers, H. W.

2016-04-01

High temperature superconducting (HTS) conductor-on-round-core (CORC®) cables have been developed for use in power transmission systems and large high-field magnets. The use of high-current conductors for large-scale magnets reduces system inductance and limits the peak voltage needed for ramped field operation. A CORC® cable contains a large number of RE-Ba2Cu3O7-δ (RE = rare earth) (REBCO) coated conductors, helically wound in multiple layers on a thin, round former. Large-scale applications, such as fusion and accelerator magnets, require current ramp rates of several kilo-Amperes per second during pulsed operation. This paper presents results that demonstrate the electromagnetic stability of a CORC® cable during transient conditions. Measurements were performed at 4.2 K using a 1.55 m long CORC® cable in background fields of up to 19 T. Repeated current pulses in a background field of 19 T at current ramp rates of up to 67.8 kA s-1 to approximately 90% of the cable’s quench current at that field, did not show any sign of degradation in cable performance due to excessive ac loss or electromagnetic instability. The very high current ramp rates applied during these tests were used to compensate, to the extent possible, the limited cable length accommodated by the test facility, assuming that the measured results could be extrapolated to longer length cables operated at proportionally lower current ramp rates. No shift of the superconducting transition to lower current was measured when the current ramp rate was increased from 25 A s-1 to 67.8 kA s-1. These results demonstrate the viability of CORC® cables for use in low-inductance magnets that operate at moderate to high current ramp rates.

Enhanced Product Stability in the Hammerhead Ribozyme†

PubMed Central

Shepotinovskaya, Irina; Uhlenbeck, Olke C.

2010-01-01

The rate of dissociation of P1, the 5′ product of hammerhead cleavage, is 100–300-fold slower in full-length hammerheads than in hammerheads that either lack or have disrupting mutations in the loop-loop tertiary interaction. The added stability requires the presence of residue 17 at the 3′ terminus of P1 but not the 2′, 3′ terminal phosphate. Since residue 17 is buried within the catalytic core of the hammerhead in the x-ray structure, we propose that the enhanced P1 stability is the result of the cooperative folding of the hammerhead around this residue. However, since the P1 is fully stabilized above 2.5 mM MgCl2 while hammerhead activity continues to increase with increasing MgCl2, it is clear that the hammerhead structure in the transition state must differ from that of the product complex. The product stabilization assay is used to test our earlier proposal that different tertiary interactions modulate the cleavage rate by differentially stabilizing the core. PMID:20423112

Exploiting current-generation graphics hardware for synthetic-scene generation

NASA Astrophysics Data System (ADS)

Tanner, Michael A.; Keen, Wayne A.

2010-04-01

Increasing seeker frame rate and pixel count, as well as the demand for higher levels of scene fidelity, have driven scene generation software for hardware-in-the-loop (HWIL) and software-in-the-loop (SWIL) testing to higher levels of parallelization. Because modern PC graphics cards provide multiple computational cores (240 shader cores for a current NVIDIA Corporation GeForce and Quadro cards), implementation of phenomenology codes on graphics processing units (GPUs) offers significant potential for simultaneous enhancement of simulation frame rate and fidelity. To take advantage of this potential requires algorithm implementation that is structured to minimize data transfers between the central processing unit (CPU) and the GPU. In this paper, preliminary methodologies developed at the Kinetic Hardware In-The-Loop Simulator (KHILS) will be presented. Included in this paper will be various language tradeoffs between conventional shader programming, Compute Unified Device Architecture (CUDA) and Open Computing Language (OpenCL), including performance trades and possible pathways for future tool development.

High-speed OH* chemiluminescence imaging of ignition through a shock tube end-wall

NASA Astrophysics Data System (ADS)

Troutman, V. A.; Strand, C. L.; Campbell, M. F.; Tulgestke, A. M.; Miller, V. A.; Davidson, D. F.; Hanson, R. K.

2016-03-01

A high-speed OH* chemiluminescence imaging diagnostic was developed to image the structure and homogeneity of combustion events behind reflected shock waves in the Stanford Constrained Reaction Volume Shock Tube. An intensified high-repetition-rate imaging system was used to acquire images of OH* chemiluminescence (near 308 nm) through a fused quartz shock tube end-wall window at 10-33 kHz during the combustion of n-heptane (21 % O2/Ar, φ = 0.5). In general, the imaging technique enabled observation of the main ignition event in the core of the shock tube that corresponded to typical markers of ignition (e.g., pressure rise), as well as localized ignition near the wall that preceded the main core ignition event for some conditions. Case studies were performed to illustrate the utility of this novel imaging diagnostic. First, by comparing localized wall ignition events to the core ignition event, the temperature homogeneity of the post-reflected shock gas near the end-wall was estimated to be within 0.5 % for the test condition presented (T=1159 hbox {K}, P=0.25 hbox {MPa}). Second, the effect of a recession in the shock tube wall, created by an observation window, on the combustion event was visualized. Localized ignition was observed near the window, but this disturbance did not propagate to the core of the shock tube before the main ignition event. Third, the effect of shock tube cleanliness was investigated by conducting tests in which the shock tube was not cleaned for multiple consecutive runs. For tests after no cleaning was performed, ignition events were concentrated in the lower half of the shock tube. In contrast, when the shock tube was cleaned, the ignition event was distributed around the entire circumference of the shock tube; validating the cleaning procedure.

Thermoregulatory and Orthostatic Responses to Wearing the Advanced Crew Escape Suit

NASA Technical Reports Server (NTRS)

Lee, Stuart M. C.; Jacobs, Tamara N.; McDaniel, Angela; Schneider, Suzanne M.

2006-01-01

Current NASA flight rules limit the maximum cabin temperature (23.9 C) during re-entry and landing to protect crewmembers from heat stress while wearing the Advanced Crew Escape Suit (ACES) and Liquid Cooling Garment (LCG). The primary purpose of this ground-based project was to determine whether the LCG could provide adequate cooling if ambient temperature reached 26.7 "C. The secondary objective was to determine whether there would be a graded effect of ambient temperature profiles with maximum temperatures of 23.9 (LO), 26.7 (MPD), and 29.4 C (HI). METHODS: Eight subjects underwent a 5-h temperature profile (22.8,26.7 C) in an environmental chamber while wearing the ACES and LCG. Subjects controlled the amount of cooling provided by the LCG. Core (T(sub core)),skin temperatures (T(sub sk)) and heart rate (HR) were measured every 15-min. A 10-minute stand test was administered pre- and post-chamber. Additionally, 4 subjects underwent the three 5-h temperature profiles (LO, MID, and HI) with the same measurements. RESULTS: In the 8 subjects completing the MID profile, T(sub core), and T(sub sk) decreased from the start' to the end of the chamber stay. Subjects completed the stand test without signs of orthostatic intolerance. In the 4 subjects who underwent all 3 profiles, there was no discernible pattern in T(sub core), T(sub sk), and HR responses across the temperature profiles. CONCLUSIONS: In the range of temperatures tested, subjects were able to sufficiently utilize the self-selected cooling to avoid any potential deleterious effects of wearing the ACES. However, these subjects were not microgravity exposed, which has been suggested to impair thermoregulation.

SLS Test Stand Site Selection

NASA Technical Reports Server (NTRS)

Crowe, Kathryn; Williams, Michael

2015-01-01

Test site selection is a critical element of the design, development and production of a new system. With the advent of the new Space Launch System (SLS), the National Aeronautics and Space Administration (NASA) had a number of test site selection decisions that needed to be made early enough in the Program to support the planned Launch Readiness Date (LRD). This case study focuses on decisions that needed to be made in 2011 and 2012 in preparation for the April 2013 DPMC decision about where to execute the Main Propulsion Test that is commonly referred to as "Green Run." Those decisions relied upon cooperative analysis between the Program, the Test Lab and Center Operations. The SLS is a human spaceflight vehicle designed to carry a crew farther into space than humans have previously flown. The vehicle consists of four parts: the crew capsule, the upper stage, the core stage, and the first stage solid rocket boosters. The crew capsule carries the astronauts, while the upper stage, the core stage, and solid rocket boosters provide thrust for the vehicle. In other words, the stages provide the "lift" part of the lift vehicle. In conjunction with the solid rocket boosters, the core stage provides the initial "get-off-the-ground" thrust to the vehicle. The ignition of the four core stage engines and two solid rocket boosters is the first step in the launch portion of the mission. The solid rocket boosters burn out after about 2 minutes of flight, and are then jettisoned. The core stage provides thrust until the vehicle reaches a specific altitude and speed, at which point the core stage is shut off and jettisoned, and the upper stage provides vehicle thrust for subsequent mission trajectories. The integrated core stage primarily consists of a liquid oxygen tank, a liquid hydrogen tank, and the four core stage engines. For the SLS program, four RS-25 engines were selected as the four core stage engines. The RS-25 engine is the same engine that was used for Space Shuttle. The test plan for the integrated core stage was broken down into several segments: Component testing, system level testing, and element level testing. In this context, components are items such as valves, controllers, sensors, etc. Systems are items such as an entire engine, a tank, or the outer stage body. The core stage itself is considered to be an element. The rocket engines are also considered an element. At the program level, it was decided to perform a single green run test on the integrated core stage prior to shipment of it to Kennedy Space Center (KSC) for use in the EM-1 test flight of the SLS vehicle. A green run test is the first live fire of the new integrated core stage and engine elements - without boosters of course. The SLS Program had to decide where to perform SLS green run testing.

[Contribution of HCV core antigen testing in HCV diagnosis by test from the company Abbott Laboratories].

PubMed

Trbusek, J

2009-11-01

Detection of HCV core antigen as direct marker of hepatitis C infection clearly improves diagnosis of this disease (especially reduction of window period) and brings broad clinical utilization. The company Abbott Laboratories offers fully automated laboratory test for measurement of HCV core antigen on ARCHITECT analyzers.

Cone Calorimeter Analysis of FRT Intumescent and Untreated Foam Core Particleboards

Treesearch

Mark A. Dietenberger; Ali Shalbafan; Johannes Welling; Charles Boardman

2012-01-01

The effectiveness of treatments of the surface layer of novel foam core particleboards were evaluated by means of Cone calorimeter tests. Foam core particleboards with variations of surface layer treatment, adhesives and surface layer thicknesses under similar processing conditions were used to produce the test specimen for the Cone calorimeter tests. Ignitability,...

[Comparison of clinical effects of Co-Cr alloy cast post-core and everStick fiber post in restoration of labially or lingually inclined maxillary central incisor].

PubMed

Qian, Yu-Mei; Zhong, Qun; Chen, Shuang

2017-02-01

To compare the clinical effect of Co-Cr alloy cast post-core and everStick fiber post in restoration of maxillary central incisor with labial or lingual inclination, and provide theoretical basis for clinical application. Ninety-seven labially or lingually inclined maxillary central incisors were treated in our hospital from March 2012 to March 2014. The patients were randomly divided into group A (n=49) and group B (n=48), and received post -core and crown restoration. Patients in group A underwent Co-Cr alloy cast post and core restoration and patients in group B underwent everStick fiber post and core restoration. After two-year of follow-up, root fracture, post break, crown or post dislodgment and gingival marginal discoloration were recorded and analyzed using SPSS 19.0 software package. Chi-square test showed that the success rate of restoration was significantly different between 2 groups (P<0.05). The incidence of root fracture and gingival marginal discoloration of Co-Cr alloy cast post-core was higher than that of everStick fiber post, but there was no significant difference in the incidence of post break, crown or post dislodgment. EverStick fiber post is better than Co-Cr alloy cast post and core to prevent root fracture and gingival marginal discoloration. Its fracture pattern is repairable and favorable for preserving tooth.

Electromyographic response of global abdominal stabilizers in response to stable- and unstable-base isometric exercise.

PubMed

Atkins, Stephen J; Bentley, Ian; Brooks, Darrell; Burrows, Mark P; Hurst, Howard T; Sinclair, Jonathan K

2015-06-01

Core stability training traditionally uses stable-base techniques. Less is known as to the use of unstable-base techniques, such as suspension training, to activate core musculature. This study sought to assess the neuromuscular activation of global core stabilizers when using suspension training techniques, compared with more traditional forms of isometric exercise. Eighteen elite level, male youth swimmers (age, 15.5 ± 2.3 years; stature, 163.3 ± 12.7 cm; body mass, 62.2 ± 11.9 kg) participated in this study. Surface electromyography (sEMG) was used to determine the rate of muscle contraction in postural musculature, associated with core stability and torso bracing (rectus abdominus [RA], external obliques [EO], erector spinae [ES]). A maximal voluntary contraction test was used to determine peak amplitude for all muscles. Static bracing of the core was achieved using a modified "plank" position, with and without a Swiss ball, and held for 30 seconds. A mechanically similar "plank" was then held using suspension straps. Analysis of sEMG revealed that suspension produced higher peak amplitude in the RA than using a prone or Swiss ball "plank" (p = 0.04). This difference was not replicated in either the EO or ES musculature. We conclude that suspension training noticeably improves engagement of anterior core musculature when compared with both lateral and posterior muscles. Further research is required to determine how best to activate both posterior and lateral musculature when using all forms of core stability training.

3D Printed "Earable" Smart Devices for Real-Time Detection of Core Body Temperature.

PubMed

Ota, Hiroki; Chao, Minghan; Gao, Yuji; Wu, Eric; Tai, Li-Chia; Chen, Kevin; Matsuoka, Yasutomo; Iwai, Kosuke; Fahad, Hossain M; Gao, Wei; Nyein, Hnin Yin Yin; Lin, Liwei; Javey, Ali

2017-07-28

Real-time detection of basic physiological parameters such as blood pressure and heart rate is an important target in wearable smart devices for healthcare. Among these, the core body temperature is one of the most important basic medical indicators of fever, insomnia, fatigue, metabolic functionality, and depression. However, traditional wearable temperature sensors are based upon the measurement of skin temperature, which can vary dramatically from the true core body temperature. Here, we demonstrate a three-dimensional (3D) printed wearable "earable" smart device that is designed to be worn on the ear to track core body temperature from the tympanic membrane (i.e., ear drum) based on an infrared sensor. The device is fully integrated with data processing circuits and a wireless module for standalone functionality. Using this smart earable device, we demonstrate that the core body temperature can be accurately monitored regardless of the environment and activity of the user. In addition, a microphone and actuator are also integrated so that the device can also function as a bone conduction hearing aid. Using 3D printing as the fabrication method enables the device to be customized for the wearer for more personalized healthcare. This smart device provides an important advance in realizing personalized health care by enabling real-time monitoring of one of the most important medical parameters, core body temperature, employed in preliminary medical screening tests.

Collection, analysis, and age-dating of sediment cores from 56 U.S. lakes and reservoirs sampled by the U.S. Geological Survey, 1992-2001

USGS Publications Warehouse

Van Metre, Peter; Wilson, Jennifer T.; Fuller, Christopher C.; Callender, Edward; Mahler, Barbara J.

2004-01-01

The U.S. Geological Survey Reconstructed Trends National Synthesis study collected sediment cores from 56 lakes and reservoirs between 1992 and 2001 across the United States. Most of the sampling was conducted as part of the National Water-Quality Assessment (NAWQA) Program. The primary objective of the study was to determine trends in particle-associated contaminants in response to urbanization; 47 of the 56 lakes are in or near one of 20 U.S. cities. Sampling was done with gravity, piston, and box corers from boats and push cores from boats or by wading, depending on the depth of water and thickness of sediment being sampled. Chemical analyses included major and trace elements, organochlorine pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, cesium-137, and lead-210. Age-dating of the cores was done on the basis of radionuclide analyses and the position of the pre-reservoir land surface in the reservoir and, in a few cases, other chemical or lithologic depth-date markers. Dates were assigned in many cores on the basis of assumed constant mass accumulation between known depth-date markers. Dates assigned were supported using a variety of other date markers including first occurrence and peak concentrations of DDT and polychlorinated biphenyls and peak concentration of lead. A qualitative rating was assigned to each core on the basis of professional judgment to indicate the reliability of age assignments. A total of 122 cores were collected from the 56 lakes and age dates were assigned to 113 of them, representing 54 of the 56 lakes. Seventy-four of the 122 cores (61 percent) received a good rating for the assigned age dates, 28 cores (23 percent) a fair rating, and 11 cores (9 percent) a poor rating; nine cores (7 percent) had no dates assigned. An analysis of the influence of environmental factors on the apparent quality of age-dating of the cores concluded that the most important factor was the mass accumulation rate (MAR) of sediment: the greater the MAR, the better the temporal discretization in the samples and the less important the effects of postdepositional sediment disturbance. These age-dated sediment cores provide the basis for local-, regional-, and national-scale interpretations of water-quality trends.

Probability-of-success studies for geothermal projects: from subsurface data to geological risk analysis

NASA Astrophysics Data System (ADS)

Schumacher, Sandra; Pierau, Roberto; Wirth, Wolfgang

2017-04-01

In recent years, the development of geothermal plants in Germany has increased significantly due to a favorable political setting and resulting financial incentives. However, most projects are developed by local communities or private investors, which cannot afford a project to fail. To cover the risk of total loss if the geothermal well should not provide the energy output necessary for an economically viable project, investors try to procure insurances for this worst case scenario. In order to issue such insurances, the insurance companies insist on so called probability-of-success studies (POS studies), in which the geological risk for not achieving the necessary temperatures and/or flow rates for an economically successful project is quantified. Quantifying the probability of reaching a minimum temperature, which has to be defined by the project investors, is relatively straight forward as subsurface temperatures in Germany are comparatively well known due tens of thousands of hydrocarbon wells. Moreover, for the German Molasse Basin a method to characterize the hydraulic potential of a site based on pump test analysis has been developed and refined in recent years. However, to quantify the probability of reaching a given flow rate with a given drawdown is much more challenging in areas where pump test data are generally not available (e.g. the North German Basin). Therefore, a new method based on log and core derived porosity and permeability data was developed to quantify the geological risk of reaching a determined flow rate in such areas. We present both methods for POS studies and show how subsurface data such as pump tests or log and core measurements can be used to predict the chances of a potential geothermal project from a geological point of view.

Rigid versus flexible dentine-like endodontic posts--clinical testing of a biomechanical concept: seven-year results of a randomized controlled clinical pilot trial on endodontically treated abutment teeth with severe hard tissue loss.

PubMed

Sterzenbach, Guido; Franke, Alexandra; Naumann, Michael

2012-12-01

This is the first clinical long-term pilot study that tested the biomimetic concept of using more flexible, dentine-like (low Young modulus) glass fiber-reinforced epoxy resin posts (GFREPs) compared with rather rigid, stiff (higher Young modulus) titanium posts (TPs) in order to improve the survival rate of severely damaged endodontically treated teeth. Ninety-one subjects in need of postendodontic restorations in teeth with 2 or less remaining cavity walls were randomly assigned to receive either a tapered TP (n = 46) or a tapered GFREP (n = 45). The posts were adhesively luted using self-adhesive resin cement. The composite core build-ups were prepared ensuring a circumferential 2-mm ferrule. The primary endpoint was a loss of restoration for any reason. To study group differences, the log-rank test was calculated (P < .05). Hazard plots were constructed. After 84 months of observation (mean = 71.2 months), 7 restorations failed (ie, 4 GFREPs and 3 TPs). The failure modes were as follows: GFREP:root fracture (n = 3), core fracture (n = 1) and TP:endodontic failure (n = 3). No statistical difference was found between the survival rates (GFREPs = 90.2%, TPs = 93.5%, P = .642). The probability of no failure was comparable for both post materials (risk ratio; 95% confidence interval, 0.965-0.851/1.095). When using self-adhesive luted prefabricated posts in severely destroyed abutment teeth with 2 or less cavity walls and a 2-mm ferrule, postendodontic restorations achieved high long-term survival rates irrespective of the post material used (ie, glass fiber vs titanium). Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The Interior Angular Momentum of Core Hydrogen Burning Stars from Gravity-mode Oscillations

NASA Astrophysics Data System (ADS)

Aerts, C.; Van Reeth, T.; Tkachenko, A.

2017-09-01

A major uncertainty in the theory of stellar evolution is the angular momentum distribution inside stars and its change during stellar life. We compose a sample of 67 stars in the core hydrogen burning phase with a {log} g value from high-resolution spectroscopy, as well as an asteroseismic estimate of the near-core rotation rate derived from gravity-mode oscillations detected in space photometry. This assembly includes 8 B-type stars and 59 AF-type stars, covering a mass range from 1.4 to 5 M ⊙, I.e., it concerns intermediate-mass stars born with a well-developed convective core. The sample covers projected surface rotation velocities v\\sin I\\in [9,242] km s-1 and core rotation rates up to 26 μHz, which corresponds to 50% of the critical rotation frequency. We find deviations from rigid rotation to be moderate in the single stars of this sample. We place the near-core rotation rates in an evolutionary context and find that the core rotation must drop drastically before or during the short phase between the end of the core hydrogen burning and the onset of core helium burning. We compute the spin parameter, which is the ratio of twice the rotation rate to the mode frequency (also known as the inverse Rossby number), for 1682 gravity modes and find the majority (95%) to occur in the sub-inertial regime. The 10 stars with Rossby modes have spin parameters between 14 and 30, while the gravito-inertial modes cover the range from 1 to 15.

Long-term survival of endodontically treated, maxillary anterior teeth restored with either tapered or parallel-sided glass-fiber posts and full-ceramic crown coverage.

PubMed

Signore, Antonio; Benedicenti, Stefano; Kaitsas, Vassilios; Barone, Michele; Angiero, Francesca; Ravera, Giambattista

2009-02-01

This retrospective study investigated the clinical effectiveness over up to 8 years of parallel-sided and of tapered glass-fiber posts, in combination with either hybrid composite or dual-cure composite resin core material, in endodontically treated, maxillary anterior teeth covered with full-ceramic crowns. The study population comprised 192 patients and 526 endodontically treated teeth, with various degrees of hard-tissue loss, restored by the post-and-core technique. Four groups were defined based on post shape and core build-up materials, and within each group post-and-core restorations were assigned randomly with respect to root morphology. Inclusion criteria were symptom-free endodontic therapy, root-canal treatment with a minimum apical seal of 4mm, application of rubber dam, need for post-and-core complex because of coronal tooth loss, and tooth with at least one residual coronal wall. Survival rate of the post-and-core restorations was determined using Kaplan-Meier statistical analysis. The restorations were examined clinically and radiologically; mean observation period was 5.3 years. The overall survival rate of glass-fiber post-and-core restorations was 98.5%. The survival rate for parallel-sided posts was 98.6% and for tapered posts was 96.8%. Survival rates for core build-up materials were 100% for dual-cure composite and 96.8% for hybrid light-cure composite. For both glass-fiber post designs and for both core build-up materials, clinical performance was satisfactory. Survival was higher for teeth retaining four and three coronal walls.

Mechanical and photoelastic analysis of conventional screws and cannulated screws for sagittal split osteotomy fixation: a comparative study.

PubMed

Lima, Cristina Jardelino de; Falci, Saulo Gabriel Moreira; Rodrigues, Danillo Costa; Marchiori, Érica Cristina; Moreira, Roger Willian Fernandes

2015-12-01

The aim of the present study was to use mechanical and photoelastic tests to compare the performance of cannulated screws with solid-core screws in sagittal split osteotomy fixation. Ten polyurethane mandibles, with a prefabricated sagittal split ramus osteotomy, were fixed with an L inverted technique and allocated to each group as follows: cannulated screw group (CSG), fixed with three 2.3-cannulated screws; and solid-core screw group (SCSG), fixed with three 2.3-solid-core screws. Vertical linear loading tests were performed. The differences between mean values were analyzed through T test for independent samples. The photoelastic test was carried out using a polariscope. The results revealed differences between the two groups only at 1 mm of displacement, in which the cannulated-screw revealed more resistance. Photoelastic test showed higher stress concentration close to mandibular branch in the solid-core group. Cannulated screws performed better than solid-core ones in a mechanical test at 1-mm displacement and photoelastic tests.

Evidence for Cluster to Cluster Variations in Low-mass Stellar Rotational Evolution

NASA Astrophysics Data System (ADS)

Coker, Carl T.; Pinsonneault, Marc; Terndrup, Donald M.

2016-12-01

The concordance model for angular momentum evolution postulates that star-forming regions and clusters are an evolutionary sequence that can be modeled with assumptions about protostar-disk coupling, angular momentum loss from magnetized winds that saturates in a mass-dependent fashion at high rotation rates, and core-envelope decoupling for solar analogs. We test this approach by combining established data with the large h Per data set from the MONITOR project and new low-mass Pleiades data. We confirm prior results that young low-mass stars can be used to test star-disk coupling and angular momentum loss independent of the treatment of internal angular momentum transport. For slow rotators, we confirm the need for star-disk interactions to evolve the ONC to older systems, using h Per (age 13 Myr) as our natural post-disk case. There is no evidence for extremely long-lived disks as an alternative to core-envelope decoupling. However, our wind models cannot evolve rapid rotators from h Per to older systems consistently, and we find that this result is robust with respect to the choice of angular momentum loss prescription. We outline two possible solutions: either there is cosmic variance in the distribution of stellar rotation rates in different clusters or there are substantially enhanced torques in low-mass rapid rotators. We favor the former explanation and discuss observational tests that could be used to distinguish them. If the distribution of initial conditions depends on environment, models that test parameters by assuming a universal underlying distribution of initial conditions will need to be re-evaluated.

Repellent activity screening of 11 kinds of essential oils against Aedes albopictus Skuse: microcapsule preparation of Herba Schizonepetae oil and repellent bioassay on hand skin.

PubMed

Wu, H; Fu, C C; Yu, D D; Feng, J T; Zhang, X; Ma, Z Q

2013-08-01

The main ingredient of most repellents on the market is DEET, an effective compound that has the disadvantages of toxic reactions as well as damaging effects on plastic and synthetic fabric. DEET alternatives are urgently needed. The repellent activities of 11 kinds of essential oils were tested against Aedes albopictus Skuse by a Y-tube olfactometer. Using essential oils with high repellent activity as core material and gelatin and gum arabic as wall materials, we prepared microcapsules of essential oils and optimized the preparation process. The microcapsule formulation was then subjected to repellent bioassay on hand skin. when the dosage of essential oils was 5 µL, the cinnamon oil repellent rate was 87.5% within 10 min and the Herba Schizonepetae oil (HSO) repellent rate was 98.0% within 3 min. Up to 1.5% (w/v) gelatin and 1.5% (w/v) gum arabic (as wall materials), and HSO (as core material) were used to form microcapsules with a 1:1 ratio of core material to wall material. The ointment preparations effectively protected hand skin exposed to a high-density A. albopictus Skuse rearing cage for 4-5 h. The HSO microcapsule repellent has broad application and development prospects.

Time and frequency structure of causal correlation networks in the China bond market

NASA Astrophysics Data System (ADS)

Wang, Zhongxing; Yan, Yan; Chen, Xiaosong

2017-07-01

There are more than eight hundred interest rates published in the China bond market every day. Identifying the benchmark interest rates that have broad influences on most other interest rates is a major concern for economists. In this paper, a multi-variable Granger causality test is developed and applied to construct a directed network of interest rates, whose important nodes, regarded as key interest rates, are evaluated with CheiRank scores. The results indicate that repo rates are the benchmark of short-term rates, the central bank bill rates are in the core position of mid-term interest rates network, and treasury bond rates lead the long-term bond rates. The evolution of benchmark interest rates from 2008 to 2014 is also studied, and it is found that SHIBOR has generally become the benchmark interest rate in China. In the frequency domain we identify the properties of information flows between interest rates, and the result confirms the existence of market segmentation in the China bond market.

Reconstructing historical atmospheric mercury deposition in Western Europe using: Misten peat bog cores, Belgium.

PubMed

Allan, Mohammed; Le Roux, Gael; Sonke, Jeroen E; Piotrowska, Natalia; Streel, Maurice; Fagel, Nathalie

2013-01-01

Four sediment cores were collected in 2008 from the Misten ombrotrophic peat bog in the Northern part of the Hautes Fagnes Plateau in Belgium. Total mercury (Hg) concentrations were analyzed to investigate the intra-site variability in atmospheric Hg deposition over the past 1,500 years. Mercury concentrations in the four cores ranged from 16 to 1,100 μg kg(-1), with the maxima between 840 and 1,100 μg kg(-1). A chronological framework was established using radiometric (210)Pb and (14)C dating of two cores (M1 and M4). Pollen horizons from these two cores were correlated with data from two additional cores, providing a consistent dating framework between all the sites. There was good agreement between atmospheric Hg accumulation rates in the four cores over time based on precise age dating and pollen chronosequences. The average Hg accumulation rate before the influence of human activities (from 500 to 1,300 AD) was 1.8 ± 1 μg m(-2)y(-1) (2SD). Maximum Hg accumulation rates ranged from 90 to 200 μg m(-2)y(-1) between 1930 and 1980 AD. During the European-North American Industrial Revolution, the mean Hg accumulation rate exceeded the pre-Industrial values by a factor of 63. Based on comparisons with historical records of anthropogenic activities in Europe and Belgium, the predominant regional anthropogenic sources of Hg during and after the Industrial Revolution were coal burning and smelter Hg emissions. Mercury accumulation rates and chronologies in the Misten cores were consistent with those reported for other European peat records. Copyright © 2012 Elsevier B.V. All rights reserved.

Efficiency of static core turn-off in a system-on-a-chip with variation

DOEpatents

Cher, Chen-Yong; Coteus, Paul W; Gara, Alan; Kursun, Eren; Paulsen, David P; Schuelke, Brian A; Sheets, II, John E; Tian, Shurong

2013-10-29

A processor-implemented method for improving efficiency of a static core turn-off in a multi-core processor with variation, the method comprising: conducting via a simulation a turn-off analysis of the multi-core processor at the multi-core processor's design stage, wherein the turn-off analysis of the multi-core processor at the multi-core processor's design stage includes a first output corresponding to a first multi-core processor core to turn off; conducting a turn-off analysis of the multi-core processor at the multi-core processor's testing stage, wherein the turn-off analysis of the multi-core processor at the multi-core processor's testing stage includes a second output corresponding to a second multi-core processor core to turn off; comparing the first output and the second output to determine if the first output is referring to the same core to turn off as the second output; outputting a third output corresponding to the first multi-core processor core if the first output and the second output are both referring to the same core to turn off.

CF6 jet engine performance improvement program. Short core exhaust nozzle performance improvement concept. [specific fuel consumption reduction

NASA Technical Reports Server (NTRS)

Fasching, W. A.

1979-01-01

The short core exhaust nozzle was evaluated in CF6-50 engine ground tests including performance, acoustic, and endurance tests. The test results verified the performance predictions from scale model tests. The short core exhaust nozzle provides an internal cruise sfc reduction of 0.9 percent without an increase in engine noise. The nozzle hardware successfully completed 1000 flight cycles of endurance testing without any signs of distress.

Contamination Control of Freeze Shoe Coring System for Collection of Aquifer Sands

NASA Astrophysics Data System (ADS)

Homola, K.; van Geen, A.; Spivack, A. J.; Grzybowski, B.; Schlottenmier, D.

2017-12-01

We have developed and tested an original device, the freeze-shoe coring system, designed to recover undisturbed samples of water contained in sand-dominated aquifers. Aquifer sands are notoriously difficult to collect together with porewater from coincident depths, as high hydraulic permeability leads to water drainage and mixing during retrieval. Two existing corer designs were reconfigured to incorporate the freeze-shoe system; a Hydraulic Piston (HPC) and a Rotary (RC) Corer. Once deployed, liquid CO­2 contained in an interior tank is channeled to coils at the core head where it changes phase, rapidly cooling the deepest portion of the core. The resulting frozen core material impedes water loss during recovery. We conducted contamination tests to examine the integrity of cores retrieved during a March 2017 yard test deployment. Perfluorocarbon tracer (PFC) was added to the drill fluid and recovered cores were subsampled to capture the distribution of PFC throughout the core length and interior. Samples were collected from two HPC and one RC core and analyzed for PFC concentrations. The lowest porewater contamination, around 0.01% invasive fluid, occurs in the center of both HPC cores. The greatest contamination (up to 10%) occurs at the disturbed edges where core material contacts drill fluid. There was lower contamination in the core interior than top, bottom, and edges, as well as significantly lower contamination in HPC cores that those recovered with the RC. These results confirm that the freeze-shoe system, proposed for field test deployments in West Bengal, India, can successfully collect intact porewater and sediment material with minimal if any contamination from drill fluid.

Does Core Area Theory Apply to STIs in Rural Environments?

PubMed Central

Gesink, Dionne C; Sullivan, Ashleigh B; Norwood, Todd; Serre, Marc L; Miller, William C

2012-01-01

Background Our objective was to determine the extent to which geographical core areas for gonorrhea and syphilis are located in rural areas, as compared to urban areas. Methods Incident gonorrhea (January 1, 2005 to December 31, 2010) and syphilis (January 1, 1999 to December 31, 2010) rates were estimated and mapped by census tract and quarter. Rurality was measured using percent rural and rural-urban commuting area (RUCA; rural, small town, micropolitan, or urban). SaTScan was used to identify spatiotemporal clusters of significantly elevated rates of infection. Clusters lasting five years or longer were considered core areas; clusters of shorter duration were considered outbreaks. Clusters were overlaid on maps of rurality and qualitatively assessed for correlation. Results Twenty gonorrhea core areas were identified; 65% in urban centers, 25% in micropolitan areas, and the remaining 10% were geographically large capturing combinations of urban, micropolitan, small town and rural environments. Ten syphilis core areas were identified with 80% in urban centers and 20% capturing two or more RUCAs. All ten of the syphilis core areas (100%) overlapped with gonorrhea core areas. Conclusions Gonorrhea and syphilis rates were high for rural parts of North Carolina; however, no core areas were identified exclusively for small towns or rural areas. The main pathway of rural STI transmission may be through the interconnectedness of urban, micropolitan, small town and rural areas. Directly addressing STIs in urban and micropolitan communities may also indirectly help address STI rates in rural and small town communities. PMID:23254115

Biocompatible core-shell magnetic nanoparticles for cancer treatment

NASA Astrophysics Data System (ADS)

Sharma, Amit; Qiang, You; Meyer, Daniel; Souza, Ryan; Mcconnaughoy, Alan; Muldoon, Leslie; Baer, Donald

2008-04-01

Nontoxic magnetic nanoparticles (MNPs) have expanded treatment delivery options in the medical world. With a size range from 2to200nm, MNPs can be compiled with most of the small cells and tissues in the living body. Monodispersive iron-iron oxide core-shell nanoparticles were prepared by our novel cluster deposition system. This unique method of preparing core-shell MNPs gives the nanoparticles a very high magnetic moment. We tested the nontoxicity and uptake of MNPs coated with/without dextrin by incubating them with rat LX-1 small cell lung cancer cells. Since core iron enhances the heating effect [L. Baker, Q. Zeing, W. Li, and S. Sullivan, J. Appl. Phys. 99, 08H106 (2006)], the rate of oxidation of iron nanoparticles was also tested in de-ionized water at a certain time interval. Both coated and noncoated MNPs were successfully uptaken by the cells, indicating that the nanoparticles were not toxic. The stability of MNPs was verified by x-ray diffraction scan after 0, 24, 48, 96, and 204h. Due to the high magnetic moment offered by MNPs produced in our laboratory, we predict that even at low applied external alternating field, the desired temperature could be reached in cancer cells in comparison to the commercially available nanoparticles. Moreover our MNPs do not require additional transfection agent, providing a cost effective means of treatment with significantly lower dosage in the body in comparison to commercially available nanoparticles.

Sport-specific endurance plank test for evaluation of global core muscle function.

PubMed

Tong, Tom K; Wu, Shing; Nie, Jinlei

2014-02-01

To examine the validity and reliability of a sports-specific endurance plank test for the evaluation of global core muscle function. Repeated-measures study. Laboratory environment. Twenty-eight male and eight female young athletes. Surface electromyography (sEMG) of selected trunk flexors and extensors, and an intervention of pre-fatigue core workout were applied for test validation. Intraclass correlation coefficient (ICC), coefficient of variation (CV), and the measurement bias ratio */÷ ratio limits of agreement (LOA) were calculated to assess reliability and measurement error. Test validity was shown by the sEMG of selected core muscles, which indicated >50% increase in muscle activation during the test; and the definite discrimination of the ∼30% reduction in global core muscle endurance subsequent to a pre-fatigue core workout. For test-retest reliability, when the first attempt of three repeated trials was considered as familiarisation, the ICC was 0.99 (95% CI: 0.98-0.99), CV was 2.0 ± 1.56% and the measurement bias ratio */÷ ratio LOA was 0.99 */÷ 1.07. The findings suggest that the sport-specific endurance plank test is a valid, reliable and practical method for assessing global core muscle endurance in athletes given that at least one familiarisation trial takes place prior to measurement. Copyright © 2013 Elsevier Ltd. All rights reserved.

Influence of PBL with open-book tests on knowledge retention measured with progress tests.

PubMed

Heijne-Penninga, M; Kuks, J B M; Hofman, W H A; Muijtjens, A M M; Cohen-Schotanus, J

2013-08-01

The influence of problem-based learning (PBL) and open-book tests on long-term knowledge retention is unclear and subject of discussion. Hypotheses were that PBL as well as open-book tests positively affect long-term knowledge retention. Four progress test results of fifth and sixth-year medical students (n = 1,648) of three medical schools were analyzed. Two schools had PBL driven curricula, and the third one had a traditional curriculum (TC). One of the PBL schools (PBLob) used a combination of open-book (assessing backup knowledge) and closed-book tests (assessing core knowledge); the other two schools (TC and PBLcb) only used closed-book tests. The items of the progress tests were divided into core and backup knowledge. T tests (with Bonferroni correction) were used to analyze differences between curricula. PBL students performed significantly better than TC students on core knowledge (average effect size (av ES) = 0.37-0.74) and PBL students tested with open-book tests scored somewhat higher than PBL students tested without such tests (av ES = 0.23-0.30). Concerning backup knowledge, no differences were found between the scores of the three curricula. Students of the two PBL curricula showed a substantially better long-term knowledge retention than TC students. PBLob students performed somewhat better on core knowledge than PBLcb students. These outcomes suggest that a problem-based instructional approach in particular can stimulate long-term knowledge retention. Distinguishing knowledge into core and backup knowledge and using open-book tests alongside closed-book tests could enhance long-term core knowledge retention.

Soil strength and macropore volume limit root elongation rates in many UK agricultural soils.

PubMed

Valentine, Tracy A; Hallett, Paul D; Binnie, Kirsty; Young, Mark W; Squire, Geoffrey R; Hawes, Cathy; Bengough, A Glyn

2012-07-01

Simple indicators of crop and cultivar performance across a range of soil types and management are needed for designing and testing sustainable cropping practices. This paper determined the extent to which soil chemical and physical properties, particularly soil strength and pore-size distribution influences root elongation in a wide range of agricultural top soils, using a seedling-based indicator. Intact soil cores were sampled from the topsoil of 59 agricultural fields in Scotland, representing a wide geographic spread, range of textures and management practices. Water release characteristics, dry bulk density and needle penetrometer resistance were measured on three cores from each field. Soil samples from the same locations were sieved, analysed for chemical characteristics, and packed to dry bulk density of 1.0 g cm(-3) to minimize physical constraints. Root elongation rates were determined for barley seedlings planted in both intact field and packed soil cores at a water content close to field capacity (-20 kPa matric potential). Root elongation in field soil was typically less than half of that in packed soils. Penetrometer resistance was typically between 1 and 3 MPa for field soils, indicating the soils were relatively hard, despite their moderately wet condition (compared with <0.2 MPa for packed soil). Root elongation was strongly linked to differences in physical rather than chemical properties. In field soil root elongation was related most closely to the volume of soil pores between 60 µm and 300 µm equivalent diameter, as estimated from water-release characteristics, accounting for 65.7 % of the variation in the elongation rates. Root elongation rate in the majority of field soils was slower than half of the unimpeded (packed) rate. Such major reductions in root elongation rates will decrease rooting volumes and limit crop growth in soils where nutrients and water are scarce.

Testing the dynamic coupling of the core-mantle and inner core boundaries

NASA Astrophysics Data System (ADS)

Driscoll, Peter E.

2015-07-01

The proposal that the seismically observed hemispherical asymmetry of Earth's inner core is controlled by the heat flux structure imposed on the outer core by the lower mantle is tested with numerical dynamo models driven by mixed thermochemical convection. We find that models driven by a single core-mantle boundary (CMB) spherical harmonic of degree and mode 2, the dominant mode in lower mantle seismic shear velocity tomography, produce a similar structure at the inner core boundary (ICB) shifted 30∘ westward. The sensitivity of the ICB to the CMB is further tested by increasing the CMB heterogeneity amplitude. In addition, two seismic tomographic models are tested: first with CMB resolution up to degree and order 4, and second with resolution up to degree and order 8. We find time-averaged ICB heat flux in these cases to be similar at large scale, with small-scale differences due to higher CMB harmonics (above degree 4). The tomographic models produce "Earth-like" magnetic fields, while similar models with twice the CMB heat flow amplitudes produce less Earth-like fields, implying that increasing CMB heterogeneity forces the model out of an Earth-like regime. The dynamic ICB heat fluxes are compared to the proposed translation mode of the inner core to test whether the CMB controls inner core growth and structure. This test indicates that, although CMB tomography is unlikely to be driving inner core translation, the ICB heat flux response is weak enough to not interfere with the most unstable translation mode, if it is occurring.

Frictional and hydraulic behaviour of carbonate fault gouge during fault reactivation - An experimental study

NASA Astrophysics Data System (ADS)

Delle Piane, Claudio; Giwelli, Ausama; Clennell, M. Ben; Esteban, Lionel; Nogueira Kiewiet, Melissa Cristina D.; Kiewiet, Leigh; Kager, Shane; Raimon, John

2016-10-01

We present a novel experimental approach devised to test the hydro-mechanical behaviour of different structural elements of carbonate fault rocks during experimental re-activation. Experimentally faulted core plugs were subject to triaxial tests under water saturated conditions simulating depletion processes in reservoirs. Different fault zone structural elements were created by shearing initially intact travertine blocks (nominal size: 240 × 110 × 150 mm) to a maximum displacement of 20 and 120 mm under different normal stresses. Meso-and microstructural features of these sample and the thickness to displacement ratio characteristics of their deformation zones allowed to classify them as experimentally created damage zones (displacement of 20 mm) and fault cores (displacement of 120 mm). Following direct shear testing, cylindrical plugs with diameter of 38 mm were drilled across the slip surface to be re-activated in a conventional triaxial configuration monitoring the permeability and frictional behaviour of the samples as a function of applied stress. All re-activation experiments on faulted plugs showed consistent frictional response consisting of an initial fast hardening followed by apparent yield up to a friction coefficient of approximately 0.6 attained at around 2 mm of displacement. Permeability in the re-activation experiments shows exponential decay with increasing mean effective stress. The rate of permeability decline with mean effective stress is higher in the fault core plugs than in the simulated damage zone ones. It can be concluded that the presence of gouge in un-cemented carbonate faults results in their sealing character and that leakage cannot be achieved by renewed movement on the fault plane alone, at least not within the range of slip measureable with our apparatus (i.e. approximately 7 mm of cumulative displacement). Additionally, it is shown that under sub seismic slip rates re-activated carbonate faults remain strong and no frictional weakening was observed during re-activation.

Experiment data report for Semiscale Mod-1 Test S-05-1 (alternate ECC injection test)

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

Feldman, E. M.; Patton, Jr., M. L.; Sackett, K. E.

Recorded test data are presented for Test S-05-1 of the Semiscale Mod-1 alternate ECC injection test series. These tests are among several Semiscale Mod-1 experiments conducted to investigate the thermal and hydraulic phenomena accompanying a hypothesized loss-of-coolant accident in a pressurized water reactor (PWR) system. Test S-05-1 was conducted from initial conditions of 2263 psia and 544/sup 0/F to investigate the response of the Semiscale Mod-1 system to a depressurization and reflood transient following a simulated double-ended offset shear of the cold leg broken loop piping. During the test, cooling water was injected into the vessel lower plenum to simulatemore » emergency core coolant injection in a PWR, with the flow rate based on system volume scaling.« less

In vitro evaluation of five core materials.

PubMed

Gu, Steven; Rasimick, Brian J; Deutsch, Allan S; Musikant, Barry L

2007-01-01

This in vitro study determined the fracture strength of five core materials supported by two different endodontic dowels. Diametral tensile strength and microhardness of the three resin composite core materials used in this study were also tested. The fracture strength study used one lanthanide-reinforced flowable resin composite (Ti-Core Auto E), one titanium- and lanthanide-reinforced composite (Ti-Core), one lanthanide-reinforced composite (Ti-Core Natural), and two metal-reinforced glass ionomer core materials (Ketac Silver and GC Miracle Mix). Two types of dowels were used: a multitiered, split-shank threaded dowel with a flange (#1 Flexi-Flange) and one without a flange design (#1 Flexi-Post). The specimens were divided into ten groups. Each tooth/dowel and core specimen was placed in a special jig at 45 degrees and subjected to a load by a universal testing machine. The diametral tensile strength and the microhardness of the three resin composite core materials were measured by a universal testing machine and Barcol hardness tester, respectively. All test groups contained ten specimens. The fracture strength value of the resin composite core materials was significantly larger ( p < 0.0001) than those for the metal-reinforced glass-ionomer core materials. Analysis of variance (ANOVA) also showed that the Flexi-Flange dowel interacted with Ti-Core and Ti-Core Auto E to significantly ( p < 0.0013) increase the fracture strength relative to the Flexi-Post. One-way ANOVA revealed that there were no significant differences between them in terms of diametral tensile strength. The Barcol hardness values of the composite core materials were statistically different ( p < 0.0001), with the Ti-Core the highest, followed by Ti-Core Natural, then Ti-Core Auto E. Resin composite core material performed better than glass ionomer material in this in vitro study. The flowable composite core material performed about the same in terms of fracture strength and diametral tensile strength compared with nonflowable composites. Combined with certain core materials, the flange design increased the fracture strength of the tooth/dowel and core combination.

Efficacy of core muscle strengthening exercise in chronic low back pain patients.

PubMed

Kumar, Tarun; Kumar, Suraj; Nezamuddin, Md; Sharma, V P

2015-01-01

Low back pain is a common health problem in human being and about 5 to 15% will develop chronic low back pain (CLBP). The clinical findings of CLBP suggest that lumbar mobility is decreased and recruitment order of core muscles is altered. In literature, there is no data about the effect of core muscles strengthening in the chronicity (short duration, long duration) of CLBP. This study evaluated the effect of core muscle strengthening intervention on chronicity of chronic low back pain. Thirty patients were recruited from the outpatient department of the National Institute for the Orthopaedically Handicapped. These 30 patients divided into two groups: A and B on the basis of duration of low back pain. Group-A patients complain about pain duration for more than twelve months and Group B complains about pain duration from three to twelve months. Both the groups were received same intervention for six weeks. Assessment was done pre intervention and post intervention after six weeks for both the groups. %For both the groups the assessment was done after six weeks for pre and post intervention. The result described both the groups showed improvement in all the outcome measures including pain as well as in function using Numerical pain rating scale, Oswestry Disability Index, Sorensen test, Gluteus Maximus Strength, Activation of transversus abdominis and Modified-Modified Schober's Test. The improvement was statistically non-significant with inter groups and significant within group. This study concludes that core muscle strengthening exercise along with lumbar flexibility and gluteus maximus strengthening is an effective rehabilitation technique for all chronic low back pain patients irrespective of duration (less than one year and more than one year) of their pain.

[Effect of Core Muscle Strengthening Exercises (Including Plank and Side Plank) on Injury Rate in Male Adult Soccer Players: A Systematic Review].

PubMed

Blasimann, Angela; Eberle, Simon; Scuderi, Manuel Markus

2018-03-01

 Soccer is seen as highly intensive sport with an increased injury rate. Male adults are the players with the highest injury incidence. Accordingly, the importance of core muscle strengthening to prevent injury has increased in the past few years. Up to date, core muscle strengthening plays an important role in different prevention programs, such as the "FIFA 11 +". The aim of this systematic review was to investigate the effect of core muscle strengthening on injury rate in male adult soccer players, including at least the known and easy exercises "plank" and "side plank", on injury rate in male adult soccer players.  The databases PubMed, PEDro, Cochrane Library, SPORTDiscus and Cinahl were searched systematically. Included studies had to comprise exercises for core muscles as an intervention (as a part of a prevention program) for adult male soccer players. The control group had to continue their usual exercise routine. The exercises "plank" and "side plank" were mandatory elements of the training program. The number of injuries and/or the injury rate (per 1000 hours) were defined as outcomes. The quality of the included studies was assessed with the PEDro scale and the Risk of Bias tool.  Seven studies with 2491 participants in total could be included. Two studies found a significant decrease in the injury rate in the intervention group (p < 0.05, p < 0.001 respectively). In two studies, no significance level was reported, but the training showed preventive effects in the intervention group. In the other three studies, no significant changes in the injury rate were found (p > 0.05).  The seven included studies differed greatly with respect to the applied methods, the chosen interventions and the obtained results. Furthermore, core muscles were never trained separately but were always part of a program containing other preventive elements. Therefore, it was difficult to compare the studies. However, prevention programs including strengthening exercises for core muscles tend to positively affect the injury rate. Based on the literature found, the research question cannot definitively be answered. In the future, further studies are needed which investigate the effect of isolated core muscle training on the injury rate of soccer players. © Georg Thieme Verlag KG Stuttgart · New York.

Delivery of prazosin hydrochloride from osmotic pump system prepared by coating the core tablet with an indentation.

PubMed

Liu, Longxiao; Wang, Jinchao; Zhu, Suyan

2007-04-01

The preparation of an osmotic pump tablet was simplified by elimination of laser drilling using prazosin hydrochloride as the model drug. The osmotic pump system was obtained by coating the indented core tablet compressed by the punch with a needle. A multiple regression equation was achieved with the experimental data of core tablet formulations, and then the formulation was optimized. The influences of the indentation size of the core tablet, environmental media, and agitation rate on drug release profile were investigated. The optimal osmotic pump tablet was found to deliver prazosin hydrochloride at an approximately constant rate up to 24 hr, and independent on both release media and agitation rate. Indentation size of core tablet hardly affected drug release in the range of 0.80-1.15 mm. The method that is simplified by elimination of laser drilling may be promising for preparation of an osmotic pump tablet.

A novel structure of transmission line pulse transformer with mutually coupled windings.

PubMed

Yu, Binxiong; Su, Jiancang; Li, Rui; Zhao, Liang; Zhang, Xibo; Wang, Junjie

2014-03-01

A novel structure of transmission line transformer (TLT) with mutually coupled windings is described in this paper. All transmission lines except the first stage of the transformer are wound on a common ferrite core for the TLT with this structure. A referral method was introduced to analyze the TLT with this structure, and an analytic expression of the step response was derived. It is shown that a TLT with this structure has a significantly slower droop rate than a TLT with other winding structures and the number of ferrite cores needed is largely reduced. A four-stage TLT with this structure was developed, whose input and output impedance were 4.2 Ω and 67.7 Ω, respectively. A frequency response test of the TLT was carried out. The test results showed that pulse response time of the TLT is several nanoseconds. The TLT described in this paper has the potential to be used as a rectangle pulse transformer with very fast response time.

Impact of the High Flux Isotope Reactor HEU to LEU Fuel Conversion on Cold Source Nuclear Heat Generation Rates

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

Chandler, David

2014-03-01

Under the sponsorship of the US Department of Energy National Nuclear Security Administration, staff members at the Oak Ridge National Laboratory have been conducting studies to determine whether the High Flux Isotope Reactor (HFIR) can be converted from high enriched uranium (HEU) fuel to low enriched uranium (LEU) fuel. As part of these ongoing studies, an assessment of the impact that the HEU to LEU fuel conversion has on the nuclear heat generation rates in regions of the HFIR cold source system and its moderator vessel was performed and is documented in this report. Silicon production rates in the coldmore » source aluminum regions and few-group neutron fluxes in the cold source moderator were also estimated. Neutronics calculations were performed with the Monte Carlo N-Particle code to determine the nuclear heat generation rates in regions of the HFIR cold source and its vessel for the HEU core operating at a full reactor power (FP) of 85 MW(t) and the reference LEU core operating at an FP of 100 MW(t). Calculations were performed with beginning-of-cycle (BOC) and end-of-cycle (EOC) conditions to bound typical irradiation conditions. Average specific BOC heat generation rates of 12.76 and 12.92 W/g, respectively, were calculated for the hemispherical region of the cold source liquid hydrogen (LH2) for the HEU and LEU cores, and EOC heat generation rates of 13.25 and 12.86 W/g, respectively, were calculated for the HEU and LEU cores. Thus, the greatest heat generation rates were calculated for the EOC HEU core, and it is concluded that the conversion from HEU to LEU fuel and the resulting increase of FP from 85 MW to 100 MW will not impact the ability of the heat removal equipment to remove the heat deposited in the cold source system. Silicon production rates in the cold source aluminum regions are estimated to be about 12.0% greater at BOC and 2.7% greater at EOC for the LEU core in comparison to the HEU core. Silicon is aluminum s major transmutation product and affects mechanical properties of aluminum including density, neutron irradiation hardening, swelling, and loss of ductility. Because slightly greater quantities of silicon will be produced in the cold source moderator vessel for the LEU core, these effects will be slightly greater for the LEU core than for the HEU core. Three-group (thermal, epithermal, and fast) neutron flux results tallied in the cold source LH2 hemisphere show greater values for the LEU core under both BOC and EOC conditions. The thermal neutron flux in the LH2 hemisphere for the LEU core is about 12.4% greater at BOC and 2.7% greater at EOC than for the HEU core. Therefore, cold neutron scattering will not be adversely affected and the 4 12 neutrons conveyed to the cold neutron guide hall for research applications will be enhanced.« less

Effects of pre-cooling procedures on intermittent-sprint exercise performance in warm conditions.

PubMed

Duffield, Rob; Marino, Frank E

2007-08-01

The aim of this study was to determine whether pre-cooling procedures improve both maximal sprint and sub-maximal work during intermittent-sprint exercise. Nine male rugby players performed a familiarisation session and three testing sessions of a 2 x 30-min intermittent sprint protocol, which consisted of a 15-m sprint every min separated by free-paced hard-running, jogging and walking in 32 degrees C and 30% humidity. The three sessions included a control condition, Ice-vest condition and Ice-bath/Ice-vest condition, with respective cooling interventions imposed for 15-min pre-exercise and 10-min at half-time. Performance measures of sprint time and % decline and distance covered during sub-maximal exercise were recorded, while physiological measures of core temperature (T (core)), mean skin temperature (T (skin)), heart rate, heat storage, nude mass, rate of perceived exertion, rate of thermal comfort and capillary blood measures of lactate [La(-)], pH, Sodium (Na(+)) and Potassium (K(+)) were recorded. Results for exercise performance indicated no significant differences between conditions for the time or % decline in 15-m sprint efforts or the distance covered during sub-maximal work bouts; however, large effect size data indicated a greater distance covered during hard running following Ice-bath cooling. Further, lowered T (core), T (skin), heart rate, sweat loss and thermal comfort following Ice-bath cooling than Ice-vest or Control conditions were present, with no differences present in capillary blood measures of [La(-)], pH, K(+) or Na(+). As such, the ergogenic benefits of effective pre-cooling procedures in warm conditions for team-sports may be predominantly evident during sub-maximal bouts of exercise.

On relative supernova rates and nucleosynthesis roles

NASA Technical Reports Server (NTRS)

Arnett, W. David; Schramm, David N.; Truran, James W.

1988-01-01

It is shown that the Ni-56-Fe-56 observed in SN 1987A argues that core collapse supernovae may be responsible for more that 50 percent of the iron in the galaxy. Furthermore it is argued that the time averaged rate of thermonuclear driven Type I supernovae may be at least an order of magnitude lower than the average rate of core collapse supernovae. The present low rate of Type II supernovae (below their time averaged rate of approx. 1/10 yr) is either because the past rate was much higher because many core collapse supernovae are dim like SN 1987A. However, even in this latter case they are only an order of magnitude dimmer that normal Type II's due to the contribution of Ni-56 decay to the light curve.

Synthetic seismograms and spectral cycles on the Andvord and Schollaert Drifts: Antarctic Peninsula

USGS Publications Warehouse

Manley, P.L.; Brachfeld, S.

2007-01-01

(Schollaert Drift) and the mouth of Andvord Bay (Andvord Drift) has been examined using synthetic seismograms. The seismograms generated from the physical properties in jumbo piston cores taken at each of these drifts (28JPC and 18JPC respectively) show good agreement with the field seismic profiles when core disturbance is taken into consideration. Both cores suggest an under-sampling of up to 30% (or compaction) during coring. This leads to inaccuracy in the evaluation of past sedimentation rates and thus interpretations on these rates may be biased.

A novel approach to a fine particle coating using porous spherical silica as core particles.

PubMed

Ishida, Makoto; Uchiyama, Jumpei; Isaji, Keiko; Suzuki, Yuta; Ikematsu, Yasuyuki; Aoki, Shigeru

2014-08-01

Abstract The applicability of porous spherical silica (PSS) was evaluated as core particles for pharmaceutical products by comparing it with commercial core particles such as mannitol (NP-108), sucrose and microcrystalline cellulose spheres. We investigated the physical properties of core particles, such as particle size distribution, flow properties, crushing strength, plastic limit, drying rate, hygroscopic property and aggregation degree. It was found that PSS was a core particle of small particle size, low friability, high water adsorption capacity, rapid drying rate and lower occurrence of particle aggregation, although wettability is a factor to be carefully considered. The aggregation and taste-masking ability using PSS and NP-108 as core particles were evaluated at a fluidized-bed coating process. The functional coating under the excess spray rate shows different aggregation trends and dissolution profiles between PSS and NP-108; thereby, exhibiting the formation of uniform coating under the excess spray rate in the case of PSS. This expands the range of the acceptable spray feed rates to coat fine particles, and indicates the possibility of decreasing the coating time. The results obtained in this study suggested that the core particle, which has a property like that of PSS, was useful in overcoming such disadvantages as large particle size, which feels gritty in oral cavity; particle aggregation; and the long coating time of the particle coating process. These results will enable the practical fine particle coating method by increasing the range of optimum coating conditions and decreasing the coating time in fluidized bed technology.

Cardiovascular effects of Zumba® performed in a virtual environment using XBOX Kinect

PubMed Central

Neves, Luceli Eunice Da Silva; Cerávolo, Mariza Paver Da Silva; Silva, Elisangela; De Freitas, Wagner Zeferino; Da Silva, Fabiano Fernandes; Higino, Wonder Passoni; Carvalho, Wellington Roberto Gomes; De Souza, Renato Aparecido

2015-01-01

[Purpose] This study evaluated the acute cardiovascular responses during a session of Zumba® Fitness in a virtual reality environment. [Subjects] Eighteen healthy volunteers were recruited. [Methods] The following cardiovascular variables: heart rate, systolic blood pressure, diastolic blood pressure, and double product were assessed before and after the practice of virtual Zumba®, which was performed as a continuous sequence of five choreographed movements lasting for 22 min. The game Zumba Fitness Core®, with the Kinect-based virtual reality system for the XBOX 360, was used to create the virtual environment. Comparisons were made among mean delta values (delta=post-Zumba® minus pre-Zumba® values) for systolic and diastolic blood pressure, heart rate, and double product using Student’s t-test for paired samples. [Results] After a single session, a significant increase was noted in all the analyzed parameters (Systolic blood pressure=18%; Diastolic blood pressure=13%; Heart rate=67%; and Double product=97%). [Conclusion] The results support the feasibility of the use of Zumba Fitness Core® with the Kinect-based virtual reality system for the XBOX 360 in physical activity programs and further favor its indication for this purpose. PMID:26504312

An examination of impact damage in glass-phenolic and aluminum honeycomb core composite panels

NASA Technical Reports Server (NTRS)

Nettles, A. T.; Lance, D. G.; Hodge, A. J.

1990-01-01

An examination of low velocity impact damage to glass-phenolic and aluminum core honeycomb sandwich panels with carbon-epoxy facesheets is presented. An instrumented drop weight impact test apparatus was utilized to inflict damage at energy ranges between 0.7 and 4.2 joules. Specimens were checked for extent of damage by cross sectional examination. The effect of core damage was assessed by subjecting impact-damaged beams to four-point bend tests. Skin-only specimens (facings not bonded to honeycomb) were also tested for comparison purposes. Results show that core buckling is the first damage mode, followed by delaminations in the facings, matrix cracking, and finally fiber breakage. The aluminum honeycomb panels exhibited a larger core damage zone and more facing delaminations than the glass-phenolic core, but could withstand more shear stress when damaged than the glass-phenolic core specimens.

MEGA-CC: computing core of molecular evolutionary genetics analysis program for automated and iterative data analysis.

PubMed

Kumar, Sudhir; Stecher, Glen; Peterson, Daniel; Tamura, Koichiro

2012-10-15

There is a growing need in the research community to apply the molecular evolutionary genetics analysis (MEGA) software tool for batch processing a large number of datasets and to integrate it into analysis workflows. Therefore, we now make available the computing core of the MEGA software as a stand-alone executable (MEGA-CC), along with an analysis prototyper (MEGA-Proto). MEGA-CC provides users with access to all the computational analyses available through MEGA's graphical user interface version. This includes methods for multiple sequence alignment, substitution model selection, evolutionary distance estimation, phylogeny inference, substitution rate and pattern estimation, tests of natural selection and ancestral sequence inference. Additionally, we have upgraded the source code for phylogenetic analysis using the maximum likelihood methods for parallel execution on multiple processors and cores. Here, we describe MEGA-CC and outline the steps for using MEGA-CC in tandem with MEGA-Proto for iterative and automated data analysis. http://www.megasoftware.net/.

Bone Formation is Affected by Matrix Advanced Glycation End Products (AGEs) In Vivo.

PubMed

Yang, Xiao; Mostafa, Ahmed Jenan; Appleford, Mark; Sun, Lian-Wen; Wang, Xiaodu

2016-10-01

Advanced glycation end products (AGEs) accumulate in bone extracellular matrix as people age. Although previous evidence shows that the accumulation of AGEs in bone matrix may impose significant effects on bone cells, the effect of matrix AGEs on bone formation in vivo is still poorly understood. To address this issue, this study used a unique rat model with autograft implant to investigate the in vivo response of bone formation to matrix AGEs. Fluorochrome biomarkers were sequentially injected into rats to label the dynamic bone formation in the presence of elevated levels of matrix AGEs. After sacrificing animals, dynamic histomorphometry was performed to determine mineral apposition rate (MAR), mineralized surface per bone surface (MS/BS), and bone formation rate (BFR). Finally, nanoindentation tests were performed to assess mechanical properties of newly formed bone tissues. The results showed that MAR, MS/BS, and BFR were significantly reduced in the vicinity of implant cores with high concentration of matrix AGEs, suggesting that bone formation activities by osteoblasts were suppressed in the presence of elevated matrix AGEs. In addition, MAR and BFR were found to be dependent on the surrounding environment of implant cores (i.e., cortical or trabecular tissues). Moreover, MS/BS and BFR were also dependent on how far the implant cores were away from the growth plate. These observations suggest that the effect of matrix AGEs on bone formation is dependent on the biological milieu around the implants. Finally, nanoindentation test results indicated that the indentation modulus and hardness of newly formed bone tissues were not affected by the presence of elevated matrix AGEs. In summary, high concentration of matrix AGEs may slow down the bone formation process in vivo, while imposing little effects on bone mineralization.

Control of the Speed of a Light-Induced Spin Transition through Mesoscale Core-Shell Architecture.

PubMed

Felts, Ashley C; Slimani, Ahmed; Cain, John M; Andrus, Matthew J; Ahir, Akhil R; Abboud, Khalil A; Meisel, Mark W; Boukheddaden, Kamel; Talham, Daniel R

2018-05-02

The rate of the light-induced spin transition in a coordination polymer network solid dramatically increases when included as the core in mesoscale core-shell particles. A series of photomagnetic coordination polymer core-shell heterostructures, based on the light-switchable Rb a Co b [Fe(CN) 6 ] c · mH 2 O (RbCoFe-PBA) as core with the isostructural K j Ni k [Cr(CN) 6 ] l · nH 2 O (KNiCr-PBA) as shell, are studied using temperature-dependent powder X-ray diffraction and SQUID magnetometry. The core RbCoFe-PBA exhibits a charge transfer-induced spin transition (CTIST), which can be thermally and optically induced. When coupled to the shell, the rate of the optically induced transition from low spin to high spin increases. Isothermal relaxation from the optically induced high spin state of the core back to the low spin state and activation energies associated with the transition between these states were measured. The presence of a shell decreases the activation energy, which is associated with the elastic properties of the core. Numerical simulations using an electro-elastic model for the spin transition in core-shell particles supports the findings, demonstrating how coupling of the core to the shell changes the elastic properties of the system. The ability to tune the rate of optically induced magnetic and structural phase transitions through control of mesoscale architecture presents a new approach to the development of photoswitchable materials with tailored properties.

Results of NanTroSEIZE Expeditions Stages 1 & 2: Deep-sea Coring Operations on-board the Deep-sea Drilling Vessel Chikyu and Development of Coring Equipment for Stage 3

NASA Astrophysics Data System (ADS)

Shinmoto, Y.; Wada, K.; Miyazaki, E.; Sanada, Y.; Sawada, I.; Yamao, M.

2010-12-01

The Nankai-Trough Seismogenic Zone Experiment (NanTroSEIZE) has carried out several drilling expeditions in the Kumano Basin off the Kii-Peninsula of Japan with the deep-sea scientific drilling vessel Chikyu. Core sampling runs were carried out during the expeditions using an advanced multiple wireline coring system which can continuously core into sections of undersea formations. The core recovery rate with the Rotary Core Barrel (RCB) system was rather low as compared with other methods such as the Hydraulic Piston Coring System (HPCS) and Extended Shoe Coring System (ESCS). Drilling conditions such as hole collapse and sea conditions such as high ship-heave motions need to be analyzed along with differences in lithology, formation hardness, water depth and coring depth in order to develop coring tools, such as the core barrel or core bit, that will yield the highest core recovery and quality. The core bit is especially important in good recovery of high quality cores, however, the PDC cutters were severely damaged during the NanTroSEIZE Stages 1 & 2 expeditions due to severe drilling conditions. In the Stage 1 (riserless coring) the average core recovery was rather low at 38 % with the RCB and many difficulties such as borehole collapse, stick-slip and stuck pipe occurred, causing the damage of several of the PDC cutters. In Stage 2, a new design for the core bit was deployed and core recovery was improved at 67 % for the riserless system and 85 % with the riser. However, due to harsh drilling conditions, the PDC core bit and all of the PDC cutters were completely worn down. Another original core bit was also deployed, however, core recovery performance was low even for plate boundary core samples. This study aims to identify the influence of the RCB system specifically on the recovery rates at each of the holes drilled in the NanTroSEIZE coring expeditions. The drilling parameters such as weight-on-bit, torque, rotary speed and flow rate, etc., were analyzed and conditions such as formation, tools, and sea conditions which directly affect core recovery have been categorized. Also discussed will be the further development of such coring equipment as the core bit and core barrel for the NanTroSEIZE Stage 3 expeditions, which aim to reach a depth of 7000 m-below the sea floor into harder formations under extreme drilling conditions.

A tale of two cores: Evaluation of 210Pb dating methods of salt marsh sediments for two cores collected 30 years apart

NASA Astrophysics Data System (ADS)

Fuller, C.; Drexler, J. Z.

2016-12-01

210Pb dating of wetland sediments is commonly used to constrain recent C accumulation rates and contaminant input histories. However, uncertainties in 210Pb-derived rates and validation of accumulation and accretion rates using an independent tracer are often not reported. We describe here 210Pb and 137Cs profiles in two cores from a salt marsh in south San Francisco Bay, California, collected in 1981 and 2011 within 5 m of each other, to compare and evaluate 210Pb dating methods. In the 1981 core, unsupported 210Pb (210PbXS) was detected to 12 cm and yielded mass accumulation rates (MAR) of 0.043 and 0.036 g/cm2/y using the Constant Flux-Constant Sedimentation method (CF:CS) and Constant Rate of Supply (CRS) methods, respectively. Accretion rates (S) of 0.17 (CF:CS) and 0.12 cm/y (CRS) were calculated from these MARs. The distinct 137Cs peak at 4-6 cm in the 1981 core is in good agreement with the210Pb-based 1963 depth (3.4 and 4 cm, CF:CS and CRS, respectively). 210PbXS was detectable to 18 cm in the 2011 core, and yielded a CF:CS MAR (0.077 g/cm2/y; S = 0.35 cm/y) that is about two times greater than the mass-weighted average CRS MAR (0.044 g/cm2/y; S = 0.16 cm/y). Broad subsurface maxima in 137Cs and 239Pu were observed between 16 and 24 cm in the 2011 core, which are 5 to 11 cm deeper than the 1963 depth calculated by the 2011 and 1981 210Pb-derived MARs. The apparent migration and broadening of bomb-fallout radionuclide peaks over 30 years negates their use in validating 210Pb dating. Because of low 210PbXS activities in both cores, the base of the 210PbXS profile and integrated activity used in CRS are underestimated, resulting in the lower CRS MARs that decrease with increasing depth. The range of MARs determined for two cores within 5 m but separated by 30 years will be used as an example to evaluate the uncertainties that need to be reported with C accumulation rates and contaminant histories derived from 210Pb dating of sediment archives.

Mode I Toughness Measurements of Core/Facesheet Bonds in Honeycomb Sandwich Structures

NASA Technical Reports Server (NTRS)

Nettles, Alan T.; Ratcliffe, James G.

2006-01-01

Composite sandwich structures will be used in many future applications in aerospace, marine and offshore industries due to the fact that the strength and stiffness to mass ratios surpass any other structural type. Sandwich structure also offers advantages over traditional stiffened panels such as ease of manufacturing and repair. During the last three decades, sandwich structure has been used extensively for secondary structure in aircraft (fuselage floors, rudders and radome structure). Sandwich structure is also used as primary structure in rotorcraft, the most common example being the trailing edge of rotor blades. As with other types of composite construction, sandwich structure exhibits several types of failure mode such as facesheet wrinkling, core crushing and sandwich buckling. Facesheet/core debonding has also been observed in the marine and aerospace industry. During this failure mode, peel stresses applied to an existing facesheet/core debond or an interface low in toughness, results in the facesheet being peeled from the core material, possibly leading to a significant loss in structural integrity of the sandwich panel. In an incident during a test on a liquid hydrogen fuel tank of the X-33 prototype vehicle, the outer graphite/epoxy facesheet and honeycomb core became debonded from the inner facesheet along significant areas, leading to failure of the tank. As a consequence of the accident; significant efforts were made to characterize the toughness of the facesheet/core bond. Currently, the only standardized method available for assessing the quality of the facesheet/core interface is the climbing drum peel test (ASTM D1781). During this test a sandwich beam is removed from a panel and the lip of one of the facesheets is attached to a drum, as shown in Fig. 1. The drum is then rotated along the sandwich beam, causing the facesheet to peel from the core. This method has two major drawbacks. First, it is not possible to obtain quantitative fracture data from the test and so the results can only be used in a qualitative manner. Second, only sandwich structure with thin facesheets can be tested (to facilitate wrapping of the facesheet around the climbing drum). In recognition of the need for a more quantitative facesheet/core fracture test, several workers have devised experimental techniques for characterizing the toughness of the facesheet/core interface. In all of these cases, the tests are designed to yield a mode I-dominated fracture toughness of the facesheet/core interface in a manner similar to that used to determine mode I fracture toughness of composite laminates. In the current work, a modified double cantilever beam is used to measure the mode I-dominated fracture toughness of the interface in a sandwich consisting of glass/phenolic honeycomb core reinforced with graphite epoxy facesheets. Two specimen configurations were tested as shown in Fig 2. The first configuration consisted of reinforcing the facesheets with aluminum blocks (Fig. 2a). In the second configuration unreinforced specimens were tested (Fig. 2b). Climbing drum peel tests were also conducted to compare the fracture behavior observed between this test and the modified double cantilever beam. This paper outlines the test procedures and data reduction strategies used to compute fracture toughness values from the tests. The effect of specimen reinforcement on fracture toughness of the facesheet/core interface is discussed.

The development and reliability of a simple field based screening tool to assess core stability in athletes.

PubMed

O'Connor, S; McCaffrey, N; Whyte, E; Moran, K

2016-07-01

To adapt the trunk stability test to facilitate further sub-classification of higher levels of core stability in athletes for use as a screening tool. To establish the inter-tester and intra-tester reliability of this adapted core stability test. Reliability study. Collegiate athletic therapy facilities. Fifteen physically active male subjects (19.46 ± 0.63) free from any orthopaedic or neurological disorders were recruited from a convenience sample of collegiate students. The intraclass correlation coefficients (ICC) and 95% Confidence Intervals (CI) were computed to establish inter-tester and intra-tester reliability. Excellent ICC values were observed in the adapted core stability test for inter-tester reliability (0.97) and good to excellent intra-tester reliability (0.73-0.90). While the 95% CI were narrow for inter-tester reliability, Tester A and C 95% CI's were widely distributed compared to Tester B. The adapted core stability test developed in this study is a quick and simple field based test to administer that can further subdivide athletes with high levels of core stability. The test demonstrated high inter-tester and intra-tester reliability. Copyright © 2015 Elsevier Ltd. All rights reserved.

Experimental Study of the Compression Response of Fluted-Core Composite Panels with Joints

NASA Technical Reports Server (NTRS)

Schultz, Marc R.; Rose, Cheryl A.; Guzman, J. Carlos; McCarville, Douglas; Hilburger, Mark W.

2012-01-01

Fluted-core sandwich composites consist of integral angled web members spaced between laminate face sheets, and may have the potential to provide benefits over traditional sandwich composites for certain aerospace applications. However, fabrication of large autoclave-cured fluted-core cylindrical shells with existing autoclaves will require that the shells be fabricated in segments, and joined longitudinally to form a complete barrel. Two different longitudinal fluted-core joint designs were considered experimentally in this study. In particular, jointed fluted-core-composite panels were tested in longitudinal compression because longitudinal compression is the primary loading condition in dry launch-vehicle barrel sections. One of the joint designs performed well in comparison with unjointed test articles, and the other joint design failed at loads approximately 14% lower than unjointed test articles. The compression-after-impact (CAI) performance of jointed fluted-core composites was also investigated by testing test articles that had been subjected to 6 ft-lb impacts. It was found that such impacts reduced the load-carrying capability by 9% to 40%. This reduction is dependent on the joint concept, component flute size, and facesheet thickness.

Core Cutting Test with Vertical Rock Cutting Rig (VRCR)

NASA Astrophysics Data System (ADS)

Yasar, Serdar; Osman Yilmaz, Ali

2017-12-01

Roadheaders are frequently used machines in mining and tunnelling, and performance prediction of roadheaders is important for project economics and stability. Several methods were proposed so far for this purpose and, rock cutting tests are the best choice. Rock cutting tests are generally divided into two groups which are namely, full scale rock cutting tests and small scale rock cutting tests. These two tests have some superiorities and deficiencies over themselves. However, in many cases, where rock sampling becomes problematic, small scale rock cutting test (core cutting test) is preferred for performance prediction, since small block samples and core samples can be conducted to rock cutting testing. Common problem for rock cutting tests are that they can be found in very limited research centres. In this study, a new mobile rock cutting testing equipment, vertical rock cutting rig (VRCR) was introduced. Standard testing procedure was conducted on seven rock samples which were the part of a former study on cutting rocks with another small scale rock cutting test. Results showed that core cutting test can be realized successfully with VRCR with the validation of paired samples t-test.

Tory II-A: a nuclear ramjet test reactor

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

Hadley, J.W.

Declassified 28 Nov 1973. The first test reactor in the Pluto program, leading to development of a nuclear ramjet engine, is called Tory II-A. While it is not an actual prototype engine, this reactor embodies a core design which is considered feasible for an engine, and operation of the reactor will provide a test of that core type as well as more generalized values in reactor design and testing. The design of Tory II-A and construction of the reactor and of its test facility are described. Operation of the Tory II-A core at a total power of 160 megawatts, withmore » 800 pounds of air per second passing through the core and emerging at a temperature of 2000 deg F, is the central objective of the test program. All other reactor and facility components exist to support operation of the core, and preliminary steps in the test program itself will be directed primarily toward ensuring attalnment of full-power operation and collection of meaningful data on core behavior during that operation. The core, 3 feet in diameter and 41/2 feet long, will be composed of bundled ceramic tubes whose central holes will provide continuous air passages from end to end of the reactor. These tubes are to be composed of a homogeneous mixture of UO/sub 2/ fuel and BeO moderator, compacted and sintered to achieve high strength and density. (30 references) (auth)« less

Parallel efficient rate control methods for JPEG 2000

NASA Astrophysics Data System (ADS)

Martínez-del-Amor, Miguel Á.; Bruns, Volker; Sparenberg, Heiko

2017-09-01

Since the introduction of JPEG 2000, several rate control methods have been proposed. Among them, post-compression rate-distortion optimization (PCRD-Opt) is the most widely used, and the one recommended by the standard. The approach followed by this method is to first compress the entire image split in code blocks, and subsequently, optimally truncate the set of generated bit streams according to the maximum target bit rate constraint. The literature proposes various strategies on how to estimate ahead of time where a block will get truncated in order to stop the execution prematurely and save time. However, none of them have been defined bearing in mind a parallel implementation. Today, multi-core and many-core architectures are becoming popular for JPEG 2000 codecs implementations. Therefore, in this paper, we analyze how some techniques for efficient rate control can be deployed in GPUs. In order to do that, the design of our GPU-based codec is extended, allowing stopping the process at a given point. This extension also harnesses a higher level of parallelism on the GPU, leading to up to 40% of speedup with 4K test material on a Titan X. In a second step, three selected rate control methods are adapted and implemented in our parallel encoder. A comparison is then carried out, and used to select the best candidate to be deployed in a GPU encoder, which gave an extra 40% of speedup in those situations where it was really employed.

The Effect of Birthrate Granularity on the Release- to- Birth Ratio for the AGR-1 In-core Experiment

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

Dawn Scates; John Walter

The AGR-1 Advanced Gas Reactor (AGR) tristructural-isotropic-particle fuel experiment underwent 13 irradiation intervals from December 2006 until November 2009 within the Idaho National Laboratory Advanced Test Reactor in support of the Next Generation Nuclear Power Plant program. During this multi-year experiment, release-to-birth rate ratios were computed at the end of each operating interval to provide information about fuel performance. Fission products released during irradiation were tracked daily by the Fission Product Monitoring System using 8-hour measurements. Birth rates calculated by MCNP with ORIGEN for as-run conditions were computed at the end of each irradiation interval. Each time step in MCNPmore » provided neutron flux, reaction rates and AGR-1 compact composition, which were used to determine birth rates using ORIGEN. The initial birth-rate data, consisting of four values for each irradiation interval at the beginning, end, and two intermediate times, were interpolated to obtain values for each 8-hour activity. The problem with this method is that any daily changes in heat rates or perturbations, such as shim control movement or core/lobe power fluctuations, would not be reflected in the interpolated data and a true picture of the system would not be presented. At the conclusion of the AGR-1 experiment, great efforts were put forth to compute daily birthrates, which were reprocessed with the 8-hour release activity. The results of this study are presented in this paper.« less

The effect of birthrate granularity on the release-to-birth ratio for the AGR-1 in-core experiment

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

D. M. Scates; J. B. Walter; J. T. Maki

The AGR-1 Advanced Gas Reactor (AGR) tristructural-isotropic-particle fuel experiment underwent 13 irradiation intervals from December 2006 until November 2009 within the Idaho National Laboratory Advanced Test Reactor in support of the Next Generation Nuclear Power Plant program. During this multi-year experiment, release-to-birth rate ratios were computed at the end of each operating interval to provide information about fuel performance. Fission products released during irradiation were tracked daily by the Fission Product Monitoring System using 8-h measurements. Birth rate calculated by MCNP with ORIGEN for as-run conditions were computed at the end of each irradiation interval. Each time step in MCNPmore » provided neutron flux, reaction rates and AGR-1 compact composition, which were used to determine birth rate using ORIGEN. The initial birth-rate data, consisting of four values for each irradiation interval at the beginning, end, and two intermediate times, were interpolated to obtain values for each 8-h activity. The problem with this method is that any daily changes in heat rates or perturbations, such as shim control movement or core/lobe power fluctuations, would not be reflected in the interpolated data and a true picture of the system would not be presented. At the conclusion of the AGR-1 experiment, great efforts were put forth to compute daily birthrates, which were reprocessed with the 8-h release activity. The results of this study are presented in this paper.« less

Is the core top modern? Observations from the eastern equatorial Pacific

NASA Astrophysics Data System (ADS)

Mekik, Figen; Anderson, Robert

2018-04-01

A compilation of ages from 67 core tops in the eastern equatorial Pacific (EEP) does not display an easily discernible regional pattern. The ages range from 790 to over 15,000 years. The youngest core tops with the highest sediment focusing factors are located in the Panama Basin. There are weak but statistically significant inverse relationships between core top age and age-model based mass accumulation rates, bioturbation depth, linear sedimentation rate and sediment focusing factors. However, we found no statistically significant relationship between core top age and calcite dissolution in sediments or 230Th-normalized mass accumulation rates. We found evidence suggesting that greater amount of sediment focusing helps to preserve the carbonate fraction of the sediment where focusing is taking place. When focusing factors are plotted against percent calcite dissolved, we observe a strong inverse relationship, and core tops younger than 4500 years tend to occur where focusing factors are high and percent calcite dissolved values are low. Using labile organic carbon fluxes to estimate bioturbation depth in the sediments results in the observation that where bioturbation depth is shallow (<4 cm), the core top age has a strong, inverse relationship with sediment accumulation rate. We used the Globorotalia menardii Fragmentation Index (MFI) as an indicator of percent calcite dissolved in deep sea sediments. There is a distinct pattern to core top calcite dissolution in the EEP which delineates bands of high surface ocean productivity as well as the clear increase in dissolution downward on the flanks of the East Pacific Rise.

Does core stability exercise improve lumbopelvic stability (through endurance tests) more than general exercise in chronic low back pain? A quasi-randomized controlled trial.

PubMed

Shamsi, Mohammad Bagher; Rezaei, Mandana; Zamanlou, Mehdi; Sadeghi, Mehdi; Pourahmadi, Mohammad Reza

2016-01-01

The aim was to compare core stability and general exercises (GEs) in chronic low back pain (LBP) patients based on lumbopelvic stability (LPS) assessment through three endurance core stability tests. There is a controversy about preference of core stability exercise (CSE) over other types of exercise for chronic LBP. Studies which have compared these exercises used other outcomes than those related to LPS. As it is claimed that CSE enhances back stability, endurance tests for LPS were used. A 16-session CSE program and a GE program with the same duration were conducted for two groups of participants. Frequency of interventions for both groups was three times a week. Forty-three people (aged 18-60 years) with chronic non-specific LBP were alternately allocated to core stability (n = 22) or GE group (n = 21) when admitted. The primary outcomes were three endurance core stability tests including: (1) trunk flexor; (2) trunk extensor; and (3) side bridge tests. Secondary outcomes were disability and pain. Measurements were taken at baseline and the end of the intervention. After the intervention, test times increased and disability and pain decreased within groups. There was no significant difference between two groups in increasing test times (p = 0.23 to p = 0.36) or decreasing disability (p = 0.16) and pain (p = 0.73). CSE is not more effective than GE for improving endurance core stability tests and reducing disability and pain in chronic non-specific LBP patients.

Proposal for a candidate core-set of fitness and strength tests for patients with childhood or adult idiopathic inflammatory myopathies

PubMed Central

van der Stap, Djamilla K.D.; Rider, Lisa G.; Alexanderson, Helene; Huber, Adam M.; Gualano, Bruno; Gordon, Patrick; van der Net, Janjaap; Mathiesen, Pernille; Johnson, Liam G.; Ernste, Floranne C.; Feldman, Brian M.; Houghton, Kristin M.; Singh-Grewal, Davinder; Kutzbach, Abraham Garcia; Munters, Li Alemo; Takken, Tim

2015-01-01

OBJECTIVES Currently there are no evidence-based recommendations regarding which fitness and strength tests to use for patients with childhood or adult idiopathic inflammatory myopathies (IIM). This hinders clinicians and researchers in choosing the appropriate fitness- or muscle strength-related outcome measures for these patients. Through a Delphi survey, we aimed to identify a candidate core-set of fitness and strength tests for children and adults with IIM. METHODS Fifteen experts participated in a Delphi survey that consisted of five stages to achieve a consensus. Using an extensive search of published literature and through the expertise of the experts, a candidate core-set based on expert opinion and clinimetric properties was developed. Members of the International Myositis Assessment and Clinical Studies Group (IMACS) were invited to review this candidate core-set during the final stage, which led to a final candidate core-set. RESULTS A core-set of fitness- and strength-related outcome measures was identified for children and adults with IIM. For both children and adults, different tests were identified and selected for maximal aerobic fitness, submaximal aerobic fitness, anaerobic fitness, muscle strength tests and muscle function tests. CONCLUSIONS The core-set of fitness and strength-related outcome measures provided by this expert consensus process will assist practitioners and researchers in deciding which tests to use in IIM patients. This will improve the uniformity of fitness and strength tests across studies, thereby facilitating the comparison of study results and therapeutic exercise program outcomes among patients with IIM. PMID:26568594

Photogrammetric technique for in-flight ranging of trailing vortices using entrained balloons

NASA Technical Reports Server (NTRS)

Snow, Walter L.; Burner, Alpheus W.; Goad, William K.

1989-01-01

A method for experimentally determining the radial distance of a probe aircraft from a trailing vortex is described. The method relies on photogrammetric triangulation of targets entrained in the vortex core. The theory and preliminary testing were described using laboratory mock-ups. Solid state video cameras were to provide data at 300 Hz rates. Practical methods for seeding the vortex are under separate investigation and are not addressed.

A History of Warming Sea Surface Temperature and Ocean Acidification Recorded by Planktonic Foraminifera Geochemistry from the Santa Barbara Basin, California

NASA Astrophysics Data System (ADS)

Osborne, E.; Thunell, R.; Bizimis, M.; Buckley, W. P., Jr.; benitez-Nelson, C. R.; Chartier, C. J.

2015-12-01

The geochemistry of foraminiferal shells has been widely used to reconstruct past conditions of the ocean and climate. Since the onset of the Industrial Revolution, anthropogenically produced CO2 has resulted in an increase in global temperatures and a decline in the mean pH of the world's oceans. The California Current System is a particularly susceptible region to ocean acidification due to natural upwelling processes that also cause a reduction in seawater pH. The trace element concentration of magnesium and boron in planktonic foraminiferal shells are used here as proxies for temperature and carbonate ion concentration ([CO32-]), respectively. Newly developed calibrations relating Mg/Ca ratios to temperature (R2 0.91) and B/Ca ratios to [CO32-] (R2 0.84) for the surface-mixed layer species Globogerina bulloides were generated using material collected in the Santa Barbara Basin sediment trap time-series. Using these empirical relationships, temperature and [CO32-] are reconstructed using a 0.5 meter long multi-core collected within the basin. 210Pb activities were used to determine a sedimentation rate for the core to estimate ages for core samples (sedimentation rate: 0.341 cm/yr). A spike in 137Cs activity is used as a tie-point to the year 1965 coinciding with the peak of nuclear bomb testing. Our down-core record extends through the mid-19th century to create a history of rising sea surface temperatures and declining [CO32-] as a result of anthropogenic CO2 emissions.

Testing for Controlled Rapid Pressurization

DOE Data Explorer

Steven Knudsen

2014-09-03

Borehole W1 is a NQ core hole drilled at our test site in Socorro. The rock is rhyolite. Borehole W1 which was used to test gas-gas explosive mixtures is 55 feet deep with casing (pinkish in the drawing) set to 35 feet. The model is a representation of the borehole and the holes we cored around the central borehole after the test. The brown colored core holes showed dye when we filled W1 with water and slightly pressurized it. This indicates there was some path between W1 and the colored core hole. The core holes are shown to their TD in the drawing. The green plane is a fracture plane which we believe is the result of the explosions of the gas mixture in W1. Data resource is a 2D .pdf Solid Works Drawing of borehole w-1

Upgrade of Irradiation Test Capability of the Experimental Fast Reactor Joyo

NASA Astrophysics Data System (ADS)

Sekine, Takashi; Aoyama, Takafumi; Suzuki, Soju; Yamashita, Yoshioki

2003-06-01

The JOYO MK-II core was operated from 1983 to 2000 as fast neutron irradiation bed. In order to meet various requirements for irradiation tests for development of FBRs, the JOYO upgrading project named MK-III program was initiated. The irradiation capability in the MK-III core will be about four times larger than that of the MK-II core. Advanced irradiation test subassemblies such as capsule type subassembly and on-line instrumentation rig are planned. As an innovative reactor safety system, the irradiation test of Self-Actuated Shutdown System (SASS) will be conducted. In order to improve the accuracy of neutron fluence, the core management code system was upgraded, and the Monte Carlo code and Helium Accumulation Fluence Monitor (HAFM) were applied. The MK-III core is planned to achieve initial criticality in July 2003.

Societal and individual burden of illness among fibromyalgia patients in France: Association between disease severity and OMERACT core domains

PubMed Central

2012-01-01

Background Patients with fibromyalgia (FM) report widespread pain, fatigue, and other functional limitations. This study aimed to provide an assessment of the burden of illness associated with FM in France and its association with disease severity and core domains as defined by Outcome Measures in Rheumatology Clinical Trials (OMERACT) for FM. Methods This cross-sectional, observational study recruited patients with a prior diagnosis of FM from 18 community-based physician offices in France. Patients completed questions about FM impact (Fibromyalgia-Impact Questionnaire [FIQ]), core symptoms (defined by OMERACT), health-related quality of life (EQ-5D), current overall health status (rated on a scale from 0 to 100), productivity, treatment satisfaction, and out-of-pocket expenses related to FM. Site staff recorded patients' treatment and health resource use based on medical record review. Costs were extrapolated from 4-week patient-reported data and 3-month clinical case report form data and calculated in 2008 Euros using a societal perspective. Tests of significance used the Kruskal-Wallis test or Fisher's Exact test where P < 0.05 was considered significant. Results Eighty-eight patients (mean 55.2 y; female:male 74:14) were recruited. The majority of patients (84.1%) were prescribed medications for FM. Patients mainly described medications as a little/not at all effective (40.0%) or somewhat effective (52.9%). Current Overall Health rating was 52.9 (± 17.8) and FIQ total score was 54.8 (± 17.3). FIQ total score was used to define FM severity, and 17 patients scored 0- < 39 (mild FM), 33 patients 39- < 59 (moderate FM), and 38 scored 59-100 (severe FM). As FM severity level worsened, patients had poorer overall health status and perceived their prescription medications to be less effective. Average cost/FM patient was higher for severe (€10,087) vs. moderate (€6,633) or mild FM (€5,473); however, the difference was not significant. Conclusions In a sample of 88 patients with FM from France, we found that FM poses a substantial economic and human burden on patients and society. FM severity level was significantly associated with patients' health status and core symptom domains. PMID:22340435

Consensus development of core competencies in intensive and critical care medicine training in China.

PubMed

Hu, Xiaoyun; Xi, Xiuming; Ma, Penglin; Qiu, Haibo; Yu, Kaijiang; Tang, Yaoqing; Qian, Chuanyun; Fang, Qiang; Wang, Yushan; Yu, Xiangyou; Xu, Yuan; Du, Bin

2016-10-16

The aim of this study is to develop consensus on core competencies required for postgraduate training in intensive care medicine. We used a combination of a modified Delphi method and a nominal group technique to create and modify the list of core competencies to ensure maximum consensus. Ideas were generated modified from Competency Based Training in Intensive Care Medicine in Europe collaboration (CoBaTrICE) core competencies. An online survey invited healthcare professionals, educators, and trainees to rate and comment on these competencies. The output from the online survey was edited and then reviewed by a nominal group of 13 intensive care professionals to identify each competence for importance. The resulting list was then recirculated in the nominal group for iterative rating. The online survey yielded a list of 199 competencies for nominal group reviewing. After five rounds of rating, 129 competencies entered the final set defined as core competencies. We have generated a set of core competencies using a consensus technique which can serve as an indicator for training program development.

Reactor Simulator Testing

NASA Technical Reports Server (NTRS)

Schoenfeld, Michael P.; Webster, Kenny L.; Pearson, Boise Jon

2013-01-01

As part of the Nuclear Systems Office Fission Surface Power Technology Demonstration Unit (TDU) project, a reactor simulator test loop (RxSim) was design & built to perform integrated testing of the TDU components. In particular, the objectives of RxSim testing was to verify the operation of the core simulator, the instrumentation and control system, and the ground support gas and vacuum test equipment. In addition, it was decided to include a thermal test of a cold trap purification design and a pump performance test at pump voltages up to 150 V since the targeted mass flow rate of 1.75 kg/s was not obtained in the RxSim at the originally constrained voltage of 120 V. This paper summarizes RxSim testing. The gas and vacuum ground support test equipment performed effectively in NaK fill, loop pressurization, and NaK drain operations. The instrumentation and control system effectively controlled loop temperature and flow rates or pump voltage to targeted settings. The cold trap design was able to obtain the targeted cold temperature of 480 K. An outlet temperature of 636 K was obtained which was lower than the predicted 750 K but 156 K higher than the cold temperature indicating the design provided some heat regeneration. The annular linear induction pump (ALIP) tested was able to produce a maximum flow rate of 1.53 kg/s at 800 K when operated at 150 V and 53 Hz. Keywords: fission, space power, nuclear, liquid metal, NaK.

Examining High-Stakes Testing--Forum. "Education Next" Talks with Joshua P. Starr and Margaret Spellings

ERIC Educational Resources Information Center

Starr, Joshua P.; Spellings, Margaret

2014-01-01

More than 40 states plan to assess student performance with new tests tied to the Common Core State Standards. In summer 2013, results from Common Core-aligned tests in New York showed a steep decline in outcomes. Common Core advocates hailed the scores as an honest accounting of school and student performance, while others worried that they…

Count every newborn; a measurement improvement roadmap for coverage data

PubMed Central

2015-01-01

Background The Every Newborn Action Plan (ENAP), launched in 2014, aims to end preventable newborn deaths and stillbirths, with national targets of ≤12 neonatal deaths per 1000 live births and ≤12 stillbirths per 1000 total births by 2030. This requires ambitious improvement of the data on care at birth and of small and sick newborns, particularly to track coverage, quality and equity. Methods In a multistage process, a matrix of 70 indicators were assessed by the Every Newborn steering group. Indicators were graded based on their availability and importance to ENAP, resulting in 10 core and 10 additional indicators. A consultation process was undertaken to assess the status of each ENAP core indicator definition, data availability and measurement feasibility. Coverage indicators for the specific ENAP treatment interventions were assigned task teams and given priority as they were identified as requiring the most technical work. Consultations were held throughout. Results ENAP published 10 core indicators plus 10 additional indicators. Three core impact indicators (neonatal mortality rate, maternal mortality ratio, stillbirth rate) are well defined, with future efforts needed to focus on improving data quantity and quality. Three core indicators on coverage of care for all mothers and newborns (intrapartum/skilled birth attendance, early postnatal care, essential newborn care) have defined contact points, but gaps exist in measuring content and quality of the interventions. Four core (antenatal corticosteroids, neonatal resuscitation, treatment of serious neonatal infections, kangaroo mother care) and one additional coverage indicator for newborns at risk or with complications (chlorhexidine cord cleansing) lack indicator definitions or data, especially for denominators (population in need). To address these gaps, feasible coverage indicator definitions are presented for validity testing. Measurable process indicators to help monitor health service readiness are also presented. A major measurement gap exists to monitor care of small and sick babies, yet signal functions could be tracked similarly to emergency obstetric care. Conclusions The ENAP Measurement Improvement Roadmap (2015-2020) outlines tools to be developed (e.g., improved birth and death registration, audit, and minimum perinatal dataset) and actions to test, validate and institutionalise proposed coverage indicators. The roadmap presents a unique opportunity to strengthen routine health information systems, crosslinking these data with civil registration and vital statistics and population-based surveys. Real measurement change requires intentional transfer of leadership to countries with the greatest disease burden and will be achieved by working with centres of excellence and existing networks. PMID:26391444

Cooling System to Treat Exercise-Induced Hyperthermia

DTIC Science & Technology

2016-06-01

temperatures . Additionally, individual variations in sweat rates, ventilation rates, fitness levels, and oxygen consumption were not...gastrointestinal MHR maximum heart rate NASA National Aeronautics and Space Administration Tc core temperature UCHS uncompensated heat stress VO2peak peak oxygen consumption ...the effectiveness of a cooling pump based patient thermal management system supplied by Aspen Systems on lowering core body temperature

SMALLER FOOTPRINT DRILLING SYSTEM FOR DEEP AND HARD ROCK ENVIRONMENTS; FEASIBILITY OF ULTRA-HIGH SPEED DIAMOND DRILLING

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

Alan Black; Arnis Judzis

2004-10-01

The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high (greater than 10,000 rpm) rotational speeds. The work includes a feasibility of concept research effort aimed at development and test results that will ultimately result in the ability to reliably drill ''faster and deeper'' possibly with rigs having a smaller footprint to be more mobile. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration rockmore » cutting with substantially lower inputs of energy and loads. The project draws on TerraTek results submitted to NASA's ''Drilling on Mars'' program. The objective of that program was to demonstrate miniaturization of a robust and mobile drilling system that expends small amounts of energy. TerraTek successfully tested ultrahigh speed ({approx}40,000 rpm) small kerf diamond coring. Adaptation to the oilfield will require innovative bit designs for full hole drilling or continuous coring and the eventual development of downhole ultra-high speed drives. For domestic operations involving hard rock and deep oil and gas plays, improvements in penetration rates is an opportunity to reduce well costs and make viable certain field developments. An estimate of North American hard rock drilling costs is in excess of $1,200 MM. Thus potential savings of $200 MM to $600 MM are possible if drilling rates are doubled [assuming bit life is reasonable]. The net result for operators is improved profit margin as well as an improved position on reserves. The significance of the ''ultra-high rotary speed drilling system'' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology. The highest rotary speed systems in oil field and mining drilling and coring today run less than 10,000 rpm--usually well below 5,000 rpm. This document details the progress to date on the program entitled ''SMALLER FOOTPRINT DRILLING SYSTEM FOR DEEP AND HARD ROCK ENVIRONMENTS; FEASIBILITY OF ULTRA-HIGH SPEED DIAMOND DRILLING'' for the period starting June 23, 2003 through September 30, 2004. TerraTek has reviewed applicable literature and documentation and has convened a project kick-off meeting with Industry Advisors in attendance. TerraTek has designed and planned Phase I bench scale experiments. Some difficulties in obtaining ultra-high speed motors for this feasibility work were encountered though they were sourced mid 2004. TerraTek is progressing through Task 3 ''Small-scale cutting performance tests''. Some improvements over early NASA experiments have been identified.« less

SMALLER FOOTPRINT DRILLING SYSTEM FOR DEEP AND HARD ROCK ENVIRONMENTS; FEASIBILITY OF ULTRA-HIGH SPEED DIAMOND DRILLING

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

Alan Black; Arnis Judzis

2004-10-01

The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high (greater than 10,000 rpm) rotational speeds. The work includes a feasibility of concept research effort aimed at development and test results that will ultimately result in the ability to reliably drill ''faster and deeper'' possibly with rigs having a smaller footprint to be more mobile. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration rockmore » cutting with substantially lower inputs of energy and loads. The project draws on TerraTek results submitted to NASA's ''Drilling on Mars'' program. The objective of that program was to demonstrate miniaturization of a robust and mobile drilling system that expends small amounts of energy. TerraTek successfully tested ultrahigh speed ({approx}40,000 rpm) small kerf diamond coring. Adaptation to the oilfield will require innovative bit designs for full hole drilling or continuous coring and the eventual development of downhole ultra-high speed drives. For domestic operations involving hard rock and deep oil and gas plays, improvements in penetration rates is an opportunity to reduce well costs and make viable certain field developments. An estimate of North American hard rock drilling costs is in excess of $1,200 MM. Thus potential savings of $200 MM to $600 MM are possible if drilling rates are doubled [assuming bit life is reasonable]. The net result for operators is improved profit margin as well as an improved position on reserves. The significance of the ''ultra-high rotary speed drilling system'' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology. The highest rotary speed systems in oil field and mining drilling and coring today run less than 10,000 rpm--usually well below 5,000 rpm. This document details the progress to date on the program entitled ''SMALLER FOOTPRINT DRILLING SYSTEM FOR DEEP AND HARD ROCK ENVIRONMENTS; FEASIBILITY OF ULTRA-HIGH SPEED DIAMOND DRILLING'' for the period starting June 23, 2003 through September 30, 2004. (1) TerraTek has reviewed applicable literature and documentation and has convened a project kick-off meeting with Industry Advisors in attendance. (2) TerraTek has designed and planned Phase I bench scale experiments. Some difficulties in obtaining ultra-high speed motors for this feasibility work were encountered though they were sourced mid 2004. (3) TerraTek is progressing through Task 3 ''Small-scale cutting performance tests''. Some improvements over early NASA experiments have been identified.« less

Preliminary Assessment of the Impact on Reactor Vessel dpa Rates Due to Installation of a Proposed Low Enriched Uranium (LEU) Core in the High Flux Isotope Reactor (HFIR)

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

Daily, Charles R.

2015-10-01

An assessment of the impact on the High Flux Isotope Reactor (HFIR) reactor vessel (RV) displacements-per-atom (dpa) rates due to operations with the proposed low enriched uranium (LEU) core described by Ilas and Primm has been performed and is presented herein. The analyses documented herein support the conclusion that conversion of HFIR to low-enriched uranium (LEU) core operations using the LEU core design of Ilas and Primm will have no negative impact on HFIR RV dpa rates. Since its inception, HFIR has been operated with highly enriched uranium (HEU) cores. As part of an effort sponsored by the National Nuclearmore » Security Administration (NNSA), conversion to LEU cores is being considered for future HFIR operations. The HFIR LEU configurations analyzed are consistent with the LEU core models used by Ilas and Primm and the HEU balance-of-plant models used by Risner and Blakeman in the latest analyses performed to support the HFIR materials surveillance program. The Risner and Blakeman analyses, as well as the studies documented herein, are the first to apply the hybrid transport methods available in the Automated Variance reduction Generator (ADVANTG) code to HFIR RV dpa rate calculations. These calculations have been performed on the Oak Ridge National Laboratory (ORNL) Institutional Cluster (OIC) with version 1.60 of the Monte Carlo N-Particle 5 (MCNP5) computer code.« less

Core and peripheral criteria of video game addiction in the game addiction scale for adolescents.

PubMed

Brunborg, Geir Scott; Hanss, Daniel; Mentzoni, Rune Aune; Pallesen, Ståle

2015-05-01

Assessment of video game addiction often involves measurement of peripheral criteria that indicate high engagement with games, and core criteria that indicate problematic use of games. A survey of the Norwegian population aged 16-74 years (N=10,081, response rate 43.6%) was carried out in 2013, which included the Gaming Addiction Scale for Adolescents (GAS). Confirmatory factor analysis showed that a two-factor structure, which separated peripheral criteria from core criteria, fitted the data better (CFI=0.963; RMSEA=0.058) compared to the original one-factor solution where all items are determined to load only on one factor (CFI=0.905, RMSEA=0.089). This was also found when we analyzed men aged ≤33 years, men aged >33 years, women aged ≤33 years, and women aged >33 years separately. This indicates that the GAS measures both engagement and problems related to video games. Multi-group measurement invariance testing showed that the factor structure was valid in all four groups (configural invariance) for the two-factor structure but not for the one-factor structure. A novel approach to categorization of problem gamers and addicted gamers where only the core criteria items are used (the CORE 4 approach) was compared to the approach where all items are included (the GAS 7 approach). The current results suggest that the CORE 4 approach might be more appropriate for classification of problem gamers and addicted gamers compared to the GAS 7 approach.

Free Electrons to Molecular Bonds and Back: Closing the Energetic Oxygen Reduction (ORR)-Oxygen Evolution (OER) Cycle Using Core-Shell Nanoelectrocatalysts.

PubMed

Strasser, Peter

2016-11-15

Nanomaterial science and electrocatalytic science have entered a successful "nanoelectrochemical" symbiosis, in which novel nanomaterials offer new frontiers for studies on electrocatalytic charge transfer, while electrocatalytic processes give meaning and often practical importance to novel nanomaterial concepts. Examples of this fruitful symbiosis are dealloyed core-shell nanoparticle electrocatalysts, which often exhibit enhanced kinetic charge transfer rates at greatly improved atom-efficiency. As such, they represent ideal electrocatalyst architectures for the acidic oxygen reduction reaction to water (ORR) and the acidic oxygen evolution reaction from water (OER) that require scarce Pt- and Ir-based catalysts. Together, these two reactions constitute the "O-cycle", a key elemental process loop in the field of electrochemical energy interconversion between electricity (free electrons) and molecular bonds (H 2 O/O 2 ), realized in the combination of water electrolyzers and hydrogen/oxygen fuel cells. In this Account, we describe our recent efforts to design, synthesize, understand, and test noble metal-poor dealloyed Pt and Ir core-shell nanoparticles for deployment in acidic polymer electrolyte membrane (PEM) electrolyzers and PEM fuel cells. Spherical dealloyed Pt core-shell particles, derived from PtNi 3 precursor alloys, showed favorable ORR activity. More detailed size-activity correlation studies further revealed that the 6-8 nm diameter range is a most desirable initial particle size range in order to maximize the particle Ni content after ORR testing and to preserve performance stability. Similarly, dealloyed and oxidized IrO x core-shell particles derived from Ni-rich Ir-Ni precursor particles proved highly efficient oxygen evolution reaction (OER) catalysts in acidic conditions. In addition to the noble metal savings in the particle cores, the Pt core-shell particles are believed to benefit in terms of their mass-based electrochemical kinetics from surface lattice strain effects that tune the adsorption energies and barriers of elementary steps. The molecular mechanism of the kinetic benefit of the dealloyed IrO x particle needs more attention, but there is mounting evidence for ligand hole effects in defect-rich IrO x shells that generate preactive oxygen centers.

Constraints on The Coupled Thermal Evolution of the Earth's Core and Mantle, The Age of The Inner Core, And The Origin of the 186Os/188Os Core(?) Signal in Plume-Derived Lavas

NASA Astrophysics Data System (ADS)

Lassiter, J. C.

2005-12-01

Thermal and chemical interaction between the core and mantle has played a critical role in the thermal and chemical evolution of the Earth's interior. Outer core convection is driven by core cooling and inner core crystallization. Core/mantle heat transfer also buffers mantle potential temperature, resulting in slower rates of mantle cooling (~50-100 K/Ga) than would be predicted from the discrepancy between current rates of surface heat loss (~44 TW) and internal radioactive heat production (~20 TW). Core/mantle heat transfer may also generate thermal mantle plumes responsible for ocean island volcanic chains such as the Hawaiian Islands. Several studies suggest that mantle plumes, in addition to transporting heat from the core/mantle boundary, also carry a chemical signature of core/mantle interaction. Elevated 186Os/188Os ratios in lavas from Hawaii, Gorgona, and in the 2.8 Ga Kostomuksha komatiites have been interpreted as reflecting incorporation of an outer core component with high time-integrated Pt/Os and Re/Os ( Brandon et al., 1999, 2003; Puchtel et al., 2005). Preferential partitioning of Os relative to Re and Pt into the inner core during inner core growth may generate elevated Re/Os and Pt/Os ratios in the residual outer core. Because of the long half-life of 190Pt (the parent of 186Os, t1/2 = 489 Ga), an elevated 186Os/188Os outer core signature in plume lavas requires that inner core crystallization began early in Earth history, most likely prior to 3.5 Ga. This in turn requires low time-averaged core/mantle heat flow (<~2.5 TW) or large quantities of heat-producing elements in the core. Core/mantle heat flow may be estimated using boundary-layer theory, by measuring the heat transported in mantle plumes, by estimating the heat transported along the outer core adiabat, or by comparing the rates of heat production, surface heat loss, and secular cooling of the mantle. All of these independent methods suggest time-averaged core/mantle heat flow of ~5-14 TW. In the absence of heat-producing elements in the core, such high heat flow rates require an inner core younger than ~1 Ga and preclude the development of significant 186Os enrichment in the outer core. Experimental studies suggest that potassium may partition into Fe-S-O liquids during core formation. Radioactive decay of potassium in the core could provide an additional heat source and reconcile geophysical evidence for high core/mantle heat flow with apparent geochemical evidence for an ancient inner core. However, high concentrations of chalcophile elements such as Cu in the mantle are inconsistent with significant segregation of a S-rich liquid during core formation, precluding K partitioning into the core by this mechanism. Furthermore, core formation scenarios that would lead to high K content in the core (e.g., core formation prior to terrestrial volatile depletion) also result in high core Pb concentrations. Core/mantle interaction would then produce strong negative correlations between 186Os/188Os and 207Pb/204Pb ratios, but such correlations are not observed. In summary, elevated 186Os/188Os ratios in some plume-derived lavas are unlikely to reflect core/mantle interaction because the inner core is too young for this isotopic signature to have developed in the outer core. Melt generation from pyroxenite or fractionation of PGEs between sulfide melts and monosulfide solid solutions provide alternative mechanisms for generating ancient mantle reservoirs with elevated Pt/Os and 186Os/188Os.

Impulse Flashover Tests at Edgar Beauchamp High Voltage Test Facility, Dixon, California, in Support of Cutler Insulator Failure Investigation

DTIC Science & Technology

2006-07-01

sites. The strength member of the safety core insulators is a fiberglass belt wrapped around pins in the end fittings. Porcelain tubes cover the belt... porcelain tube and heavily tracked the fiberglass belt but left the belt intact structurally (Figure 1). Figure 1. Cutler safety core insulator ...fail-safe insulators . For these tests, the porcelain tube of the safety core insulator was replaced with a plastic see-through tube. The test report [5

Test Anxiety, Computer-Adaptive Testing and the Common Core

ERIC Educational Resources Information Center

Colwell, Nicole Makas

2013-01-01

This paper highlights the current findings and issues regarding the role of computer-adaptive testing in test anxiety. The computer-adaptive test (CAT) proposed by one of the Common Core consortia brings these issues to the forefront. Research has long indicated that test anxiety impairs student performance. More recent research indicates that…

Damage Tolerance of Sandwich Plates with Debonded Face Sheets

NASA Technical Reports Server (NTRS)

Avery, John L., III; Sankar, Bhavani V.

1998-01-01

Axial compression tests were performed on debonded sandwich composites made of graphite/epoxy face-sheets and aramid fiber honeycomb core. The sandwich beams were manufactured using a vacuum baccrin2 process. The face-sheet and the sandwich beam were co-cured. Delamination between one of the face sheets and the core was introduced by using a Teflon layer during the curing process. Axial compression tests were performed to determine the ultimate load carrying capacity of the debonded beams. Flatwise tension tests and Double Cantilever Beam tests were performed to determine. respectively, the strength and fracture toughness of the face-sheet/core interface. From the test results semi-empirical formulas were derived for the fracture toughness and ultimate compressive load carrying capacity in terms of the core density. core thickness. face-sheet thickness and debond length. Four different failure modes and their relation to the structural properties were identified. Linear buckling analysis was found to be inadequate in predicting the compressive load carrying capacity of the debonded sandwich composites.

Multiple Days of Heat Exposure on Firefighters' Work Performance and Physiology.

PubMed

Larsen, Brianna; Snow, Rod; Vincent, Grace; Tran, Jacqueline; Wolkow, Alexander; Aisbett, Brad

2015-01-01

This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36) were matched and allocated to either the CON (19°C) or HOT (33°C) condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area) to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc), and skin temperature (Tsk) were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG) analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants' doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants' work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of physiological responses (e.g., heart rate, core temperature).

Multiple Days of Heat Exposure on Firefighters’ Work Performance and Physiology

PubMed Central

Larsen, Brianna; Snow, Rod; Vincent, Grace; Tran, Jacqueline; Wolkow, Alexander; Aisbett, Brad

2015-01-01

This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36) were matched and allocated to either the CON (19°C) or HOT (33°C) condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area) to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc), and skin temperature (Tsk) were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG) analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants’ doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants’ work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of physiological responses (e.g., heart rate, core temperature). PMID:26379284

Fructose Administration Increases Intraoperative Core Temperature by Augmenting Both Metabolic Rate and the Vasoconstriction Threshold

PubMed Central

Mizobe, Toshiki; Nakajima, Yasufumi; Ueno, Hiroshi; Sessler, Daniel I.

2006-01-01

Background We tested the hypothesis that intravenous fructose ameliorates intraoperative hypothermia both by increasing metabolic rate and the vasoconstriction threshold (triggering core temperature) Methods 40 patients scheduled for open abdominal surgery were divided into two equal groups and randomly assigned to intravenous fructose infusion (0.5 g·kg−1·h−1 for 4 h, starting 3 h before induction of anesthesia and continuing for 4 hours) or an equal volume of saline. Each treatment group was subdivided: esophageal core temperature, thermoregulatory vasoconstriction, and plasma concentrations were determined in half, and oxygen consumption was determined in the remainder. Patients were monitored for 3 h after induction of anesthesia. Results Patient characteristics, anesthetic management, and circulatory data were similar in the four groups. Mean final core temperature (3 h after induction of anesthesia) was 35.7±0.4°C (mean ± SD) in the fructose group and 35.1±0.4°C in the saline group (P=0.001). The vasoconstriction threshold was greater in the fructose (36.2±0.3°C) than in the saline group (35.6±0.3°C; P<0.001). Oxygen consumption immediately before anesthesia induction in the fructose group (214±18 ml/min) was significantly greater than in the saline group (181±8 ml/min, P<0.001). Oxygen consumption was 4.0 L greater in the fructose patients during 3 hours of anesthesia; the predicted difference in mean-body temperature based only on the difference in metabolic rates was thus only 0.4°C. Epinephrine, norepinephrine, and angiotensin II concentrations, and plasma renin activity were similar in each treatment group. Conclusions Preoperative fructose infusion helped maintain normothermia by augmenting both metabolic heat production and increasing the vasoconstriction threshold. PMID:16732081

Peat Accumulation in the Everglades (USA) during the Past 4000 Years: Rates, Drivers, and Sources of Error

NASA Astrophysics Data System (ADS)

Glaser, P. H.; Volin, J. C.; Givnish, T. J.; Hansen, B. C.; Stricker, C. A.

2012-12-01

Tropical and sub-tropical wetlands are considered to be globally important sources for greenhouse gases but their capacity to store carbon is presumably limited by warm soil temperatures and high rates of decomposition. Unfortunately, these assumptions can be difficult to test across long timescales because the chronology, cumulative mass, and completeness of a sedimentary profile are often difficult to establish. We therefore made a detailed analysis of a core from the principal drainage outlet of the Everglades of South Florida, to assess these problems and determine the factors that could govern carbon accumulation in this large sub-tropical wetland. AMS-14C dating provided direct evidence for both hard-water and open-system sources of dating errors, whereas cumulative mass varied depending upon the type of method used. Radiocarbon dates of gastropod shells, nevertheless, seemed to provide a reliable chronology for this core once the hard-water error was quantified and subtracted. Long-term accumulation rates were then calculated to be 12.1 g m-2 yr-1 for carbon, which is less than half the average rate reported for northern and tropical peatlands. Moreover, accumulation rates remained slow and relatively steady for both organic and inorganic strata, and the slow rate of sediment accretion ( 0.2 mm yr-1) tracked the correspondingly slow rise in sea level (0.35 mm yr-1 ) reported for South Florida over the past 4000 years. These results suggest that sea level and the local geologic setting may impose long-term constraints on rates of sediment and carbon accumulation in the Everglades and other wetlands

EVIDENCE FOR CLUSTER TO CLUSTER VARIATIONS IN LOW-MASS STELLAR ROTATIONAL EVOLUTION

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

Coker, Carl T.; Pinsonneault, Marc; Terndrup, Donald M., E-mail: coker@astronomy.ohio-state.edu, E-mail: pinsono@astronomy.ohio-state.edu, E-mail: terndrup@astronomy.ohio-state.edu

2016-12-10

The concordance model for angular momentum evolution postulates that star-forming regions and clusters are an evolutionary sequence that can be modeled with assumptions about protostar–disk coupling, angular momentum loss from magnetized winds that saturates in a mass-dependent fashion at high rotation rates, and core-envelope decoupling for solar analogs. We test this approach by combining established data with the large h Per data set from the MONITOR project and new low-mass Pleiades data. We confirm prior results that young low-mass stars can be used to test star–disk coupling and angular momentum loss independent of the treatment of internal angular momentum transport.more » For slow rotators, we confirm the need for star–disk interactions to evolve the ONC to older systems, using h Per (age 13 Myr) as our natural post-disk case. There is no evidence for extremely long-lived disks as an alternative to core-envelope decoupling. However, our wind models cannot evolve rapid rotators from h Per to older systems consistently, and we find that this result is robust with respect to the choice of angular momentum loss prescription. We outline two possible solutions: either there is cosmic variance in the distribution of stellar rotation rates in different clusters or there are substantially enhanced torques in low-mass rapid rotators. We favor the former explanation and discuss observational tests that could be used to distinguish them. If the distribution of initial conditions depends on environment, models that test parameters by assuming a universal underlying distribution of initial conditions will need to be re-evaluated.« less

10 CFR Appendix A to Part 50 - General Design Criteria for Nuclear Power Plants

Code of Federal Regulations, 2012 CFR

2012-01-01

... Heat Removal 34 Emergency Core Cooling 35 Inspection of Emergency Core Cooling System 36 Testing of Emergency Core Cooling System 37 Containment Heat Removal 38 Inspection of Containment Heat Removal System 39 Testing of Containment Heat Removal System 40 Containment Atmosphere Cleanup 41 Inspection of...

10 CFR Appendix A to Part 50 - General Design Criteria for Nuclear Power Plants

Code of Federal Regulations, 2011 CFR

2011-01-01

... Heat Removal 34 Emergency Core Cooling 35 Inspection of Emergency Core Cooling System 36 Testing of Emergency Core Cooling System 37 Containment Heat Removal 38 Inspection of Containment Heat Removal System 39 Testing of Containment Heat Removal System 40 Containment Atmosphere Cleanup 41 Inspection of...

Fundamentals of Marketing Core Curriculum. Test Items and Assessment Techniques.

ERIC Educational Resources Information Center

Smith, Clifton L.; And Others

This document contains multiple choice test items and assessment techniques for Missouri's fundamentals of marketing core curriculum. The core curriculum is divided into these nine occupational duties: (1) communications in marketing; (2) economics and marketing; (3) employment and advancement; (4) human relations in marketing; (5) marketing…

Tuned Chamber Core Panel Acoustic Test Results

NASA Technical Reports Server (NTRS)

Schiller, Noah H.; Allen, Albert R.

2016-01-01

This report documents acoustic testing of tuned chamber core panels, which can be used to supplement the low-frequency performance of conventional acoustic treatment. The tuned chamber core concept incorporates low-frequency noise control directly within the primary structure and is applicable to sandwich constructions with a directional core, including corrugated-, truss-, and fluted-core designs. These types of sandwich structures have long, hollow channels (or chambers) in the core. By adding small holes through one of the facesheets, the hollow chambers can be utilized as an array of low-frequency acoustic resonators. These resonators can then be used to attenuate low-frequency noise (below 400 Hz) inside a vehicle compartment without increasing the weight or size of the structure. The results of this test program demonstrate that the tuned chamber core concept is effective when used in isolation or combined with acoustic foam treatments. Specifically, an array of acoustic resonators integrated within the core of the panels was shown to improve both the low-frequency absorption and transmission loss of the structure in targeted one-third octave bands.

Development of lightweight graphite/polyimide sandwich panels, phases 3, 4 and 5

NASA Technical Reports Server (NTRS)

Merlette, J. B.

1972-01-01

Work performed in the last three phases of the program included: (1) face sheet processing; (2) honeycomb core manufacture; (3) face sheet-to-core bonding development; and (4) sandwich panel fabrication and testing. Resin cure studies were a major portion of this effort since processing problems traced to the polyimide matrix resin had to be resolved before quality core and face sheets could be fabricated. Honeycomb core fabrication and testing were conducted by Hexcel Corporation. A total of four graphite/polyimide resin composite cores were fabricated, tested, and reported. Two sandwich panels weighing .48 and .58 lb/sq ft, respectively were designed and fabricated which meet the support structure loads for the shuttle orbiter thermal protection system.

Improving nurse practitioners' competence with genetics: Effectiveness of an online course.

PubMed

Whitt, Karen J; Macri, Charles; O'Brien, Travis J; Wright, Stephanie

2016-03-01

The purpose of this study was to assess the effectiveness of an online genetics course for improving nurse practitioners' knowledge, competence, and comfort with genetic principles and their application to clinical practice. A genetics knowledge test and survey were administered to 232 nurse practitioner students, between 2011 and 2013, before and after completing a 15-week online genetics course taught by a multidisciplinary team of instructors at a private east coast U.S. university. The 65-item survey allowed participants to rate competence regarding genetic principles, diseases, and terminology, as well as comfort performing various clinical tasks related to genetics. The 21-item knowledge test contained multiple choice questions regarding core competencies in genetics. Paired t-tests were used to compare mean pre- and postscores. Participants significantly increased postcourse knowledge (p < .001) and comfort with genetic core competencies and clinical skills related to genetics (p < .001). This study demonstrates the effectiveness of an online genetics course for increasing nurse practitioners' knowledge, competence, and confidence with genetics and identifies specific topics educators should consider when designing curricula for nurse practitioners. Findings from this study can improve genetics education for nurse practitioners, which will in turn improve patient health. ©2015 American Association of Nurse Practitioners.

Diagnostic performance of power doppler and ultrasound contrast agents in early imaging-based diagnosis of organ-confined prostate cancer: Is it possible to spare cores with contrast-guided biopsy?

PubMed

Delgado Oliva, F; Arlandis Guzman, S; Bonillo García, M; Broseta Rico, E; Boronat Tormo, F

2016-10-01

To evaluate the diagnostic performance of gray scale transrectal ultrasound-B-mode US (BMUS), power Doppler (PDUS), and sonographic contrast (CEUS) in early imaging-based diagnosis of localized prostate cancer (PCa) and to compare the diagnostic profitability of randomized biopsy (RB), US-targeted prostate biopsy by means of PDUS and CEUS. A single-center, prospective, transversal, epidemiological study was conducted from January 2010 to January 2014. We consecutively included patients who an imaging study of the prostate with BMUS, PDUS, and CEUS was performed, followed by prostate biopsy due to clinical suspicion of prostate cancer (PSA 4-20ng/mL and/or rectal exam suggestive of malignancy). The diagnostic performance of BMUS, PDUS, and CEUS was determined by calculating the Sensitivity (S), Specificity (Sp), Predictive values (PV), and diagnostic odds ratio (OR) of the diagnosis tests and, for these variables, in the population general and based on their clinical stage according to rectal exam (cT1 and cT2). PCa detection rates determined by means of a randomized 10-core biopsy scheme were compared with detection rates of CEUS-targeted (SonoVue) 2-core biopsies. Of the initial 984 patients, US contrast SonoVue was administered to 179 (18.2%). The PCa detection rate by organ of BMUS/PDUS in the global population was 38% versus 43% in the subpopulation with CEUS. The mean age of the patients was 64.3±7.01years (95% CI, 63.75-64.70); mean total PSA was 8.9±3.61ng/mL (95% CI, 8.67-9.13) and the mean prostate volume was 56.2±29cc (95% CI, 54.2-58.1). The detection rate by organ of targeted biopsy with BMUS, PDUS, and CEUS were as follows: Global population (10.6, 8.2, 24.5%), stage cT1 (5.6, 4.2, 16.4%), and stage cT2 (32.4, 22.3, 43.5%). Comparing the detection rates of the CEUS-targeted biopsy and randomized biopsy, the following results were obtained: Global population (24.5% vs. 41.8%), stage cT1 (16% vs. 35%), and stage cT2 (43.5% vs. 66.6%), with a p value<0.05. Following the "core-by-core" analysis, the detection rates by core of CEUS-targeted biopsy versus randomized biopsy were: Global population (16% vs. 13%), stage cT1 (30.3% vs. 28%), and stage cT2 (48% vs. 37%), with a p value>0.05. The NNT for CEUS-targeted biopsy was 83.3. The low sensitivity, specificity, positive predictive and negative predictive values of gray scale-B-mode, PDUS and CEUS represent scant diagnostic performance of these variables in prostate cancer detection. Prostate cancer detection rates yielded by randomized biopsy were superior than the detection rate of targeted biopsy using B-mode, PDUS and CEUS; as a result, randomized biopsy versus CEUS-targeted biopsies cannot be excluded from biopsy strategy plans for the diagnosis of prostate cancer. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Perkins Core Performance Measures: Results and Targets, 1999-2000.

ERIC Educational Resources Information Center

McHewitt, Earl R.; Taylor, Garry

This document describes the Virginia Community College System (VCCS) Core Indicators for the Perkins III Core Performance Standards and Measures. Core indicators and measures include: (1) student attainment, measured by academic and technical skills; (2) completion, measured by graduation rate; (3) placement and persistence, measured by placement,…

Plasma Hsp72 (HSPA1A) and Hsp27 (HSPB1) expression under heat stress: influence of exercise intensity.

PubMed

Périard, Julien D; Ruell, Patricia; Caillaud, Corinne; Thompson, Martin W

2012-05-01

Extracellular heat-shock protein 72 (eHsp72) expression during exercise-heat stress is suggested to increase with the level of hyperthermia attained, independent of the rate of heat storage. This study examined the influence of exercise at various intensities to elucidate this relationship, and investigated the association between eHsp72 and eHsp27. Sixteen male subjects cycled to exhaustion at 60% and 75% of maximal oxygen uptake in hot conditions (40°C, 50% RH). Core temperature, heart rate, oxidative stress, and blood lactate and glucose levels were measured to determine the predictor variables associated with eHsp expression. At exhaustion, heart rate exceeded 96% of maximum in both conditions. Core temperature reached 39.7°C in the 60% trial (58.9 min) and 39.0°C in the 75% trial (27.2 min) (P < 0.001). The rate of rise in core temperature was 2.1°C h(-1) greater in the 75% trial than in the 60% trial (P < 0.001). A significant increase and correlation was observed between eHsp72 and eHsp27 concentrations at exhaustion (P < 0.005). eHsp72 was highly correlated with the core temperature attained (60% trial) and the rate of increase in core temperature (75% trial; P < 0.05). However, no common predictor variable was associated with the expression of both eHsps. The similarity in expression of eHsp72 and eHsp27 during moderate- and high-intensity exercise may relate to the duration (i.e., core temperature attained) and intensity (i.e., rate of increase in core temperature) of exercise. Thus, the immuno-inflammatory release of eHsp72 and eHsp27 in response to exercise in the heat may be duration and intensity dependent.

Quaternary displacement rates on the Meeman‐Shelby fault and Joiner ridge horst, eastern Arkansas: Results from coring Mississippi River alluvium

USGS Publications Warehouse

Ward, Alex; Counts, Ronald C.; Van Arsdale, Roy; Larsen, Daniel; Mahan, Shannon

2017-01-01

This research used coring and optically stimulated luminescence (OSL) dating of displaced, deeply buried Quaternary alluvium to determine vertical displacement rates for the Meeman‐Shelby fault and the Joiner ridge horst, two structures in northeastern Arkansas that have no modern seismicity associated with them. We drilled continuous cores of the entire alluvial section in the hanging wall of each structure, performed detailed core descriptions and analyses, and obtained three OSL ages from each core. The Meeman‐Shelby fault core consists of 36 m of 4.3–5.2‐ka Holocene alluvium overlying 4 m of 14.3‐ka Kennett alluvium that in turn overlies the upper part of Eocene Claiborne Group sediments at a depth of 41 m. Seismic reflection indicates that the basal (Kennett) alluvium at the Meeman‐Shelby fault is displaced ∼28  m across the Meeman‐Shelby fault, which equates to a time‐averaged vertical displacement rate of 2  mm/yr within the last 14.3 ka. The Joiner ridge horst core consists, in descending order, of 11 m of 6.3‐ka Holocene alluvium, 14 m of 11.5‐ka Morehouse alluvium, a paleosol, 6 m of Kennett alluvium, and 4 m of 20.3‐ka Sikeston alluvium that in turn overlies the upper part of Eocene Claiborne Group sediments at a depth of 36 m. Lignite exploration drilling conducted in the 1970s indicates that basal (Sikeston) alluvium is displaced ∼20  m across the eastern bounding fault of the Joiner ridge horst, resulting in a time‐averaged vertical displacement rate of ∼1  mm/yr within the last 20.3 ka. These late Quaternary displacement rates are comparable to time‐averaged displacement rates of faults within the active New Madrid seismic zone.

Double-diffusive translation of Earth's inner core

NASA Astrophysics Data System (ADS)

Deguen, R.; Alboussiére, T.; Labrosse, S.

2018-03-01

The hemispherical asymmetry of the inner core has been interpreted as resulting form a high-viscosity mode of inner core convection, consisting in a translation of the inner core. A thermally driven translation, as originally proposed, is unlikely if the currently favoured high values of the thermal conductivity of iron at core conditions are correct. We consider here the possibility that inner core translation results from an unstable compositional gradient, which would develop either because the light elements present in the core become increasingly incompatible as the inner core grows, or because of a possibly positive feedback of the development of the F-layer on inner core convection. Though the magnitude of the destabilising effect of the compositional field is predicted to be similar to or smaller than the stabilising effect of the thermal field, the huge difference between thermal and chemical diffusivities implies that double-diffusive instabilities can still arise even if the net buoyancy increases upward. Using linear stability analysis and numerical simulations, we demonstrate that a translation mode can indeed exist if the compositional field is destabilising, even if the temperature profile is subadiabatic, and irrespectively of the relative magnitudes of the composition and potential temperature gradients. The existence of this double diffusive mode of translation requires that the following conditions are met: (i) the compositional profile within the inner core is destabilising, and remains so for a duration longer than the destabilisation timescale (on the order of 200 My, but strongly dependent on the magnitude of the initial perturbation); and (ii) the inner core viscosity is sufficiently large, the required value being a strongly increasing function of the inner core size (e.g. 1017 Pa.s when the inner core was 200 km in radius, and ≃ 3 × 1021 Pa.s at the current inner core size). If these conditions are met, the predicted inner core translation rate is found to be similar to the inner core growth rate, which is more consistent with inferences from the geomagnetic field morphology and secular variation than the higher translation rate predicted for a thermally driven translation.

Oximetry in children recovering from deep hypothermia for cardiac surgery.

PubMed

Macnab, A J; Baker-Brown, G; Anderson, E E

1990-10-01

Although pulse oximetry is a potentially useful diagnostic tool in the treatment of children after major open heart surgery, there are concerns regarding its reliability for measuring oxygen saturation (SaO2) in hypothermic or low perfusion states. To test pulse oximeter reliability in children under these conditions, our study compared 187 SaO2 pulse oximeter readings (Biox 3700) with simultaneous hemoximeter (OSM2, Radiometer) readings from 56 children rewarming after open heart surgery. Ages ranged from 4 months to 18 yr; temperatures ranged from 23.5 degrees to 38 degrees C (toe) and 31.3 degrees to 40.8 degrees C (core). The mean pulse oximeter SaO2 reading was 94.90% (SD 7.18, range 54% to 100%), mean hemoximeter reading was 96.07% (SD 7.06; minimum 54%; maximum 100%). The correlation between the readings was high (r = .88, p less than .005), and was not affected by low core temperature. When oximeter and cardiac monitor pulse rates coincided, the oximeter SaO2 value was within +/- 5% (p less than .05). We conclude that the Biox 3700 oximeter is reliable for noninvasive SaO2 monitoring in mild to moderately hypothermic children after open heart surgery, particularly when oximeter and cardiac heart rates coincide. Further studies are needed to confirm our findings in children with core temperatures less than 31.3 degrees C, and when other oximeters are used.

Quantifying soil surface photolysis under conditions simulating water movement in the field: a new laboratory test design.

PubMed

Hand, Laurence H; Nichols, Carol; Kuet, Sui F; Oliver, Robin G; Harbourt, Christopher M; El-Naggar, Essam M

2015-10-01

Soil surface photolysis can be a significant dissipation pathway for agrochemicals under field conditions, although it is assumed that such degradation ceases once the agrochemical is transported away from the surface following rainfall or irrigation and subsequent drainage of soil porewater. However, as both downward and upward water movements occur under field conditions, relatively mobile compounds may return to the surface, prolonging exposure to ultraviolet light and increasing the potential for degradation by photolysis. To test this hypothesis, a novel experimental system was used to quantify the contribution of photolysis to the overall dissipation of a new herbicide, bicyclopyrone, under conditions that mimicked field studies more closely than the standard laboratory test guidance. Soil cores were taken from 3 US field study sites, and the surfaces were treated with [(14) C]-bicyclopyrone. The radioactivity was redistributed throughout the cores using a simulated rainfall event, following which the cores were incubated under a xenon-arc lamp with continuous provision of moisture from below and a wind simulator to induce evaporation. After only 2 d, most of the test compound had returned to the soil surface. Significantly more degradation was observed in the irradiated samples than in a parallel dark control sample. Degradation rates were very similar to those observed in both the thin layer photolysis study and the field dissipation studies and significantly faster than in the soil metabolism studies conducted in the dark. Thus, for highly soluble, mobile agrochemicals, such as bicyclopyrone, photolysis is not terminated permanently by rainfall or irrigation but can resume following transport to the surface in evaporating water. © 2015 SETAC.

Deuterium chemistry in the young massive protostellar core NGC 2264 CMM3

NASA Astrophysics Data System (ADS)

Awad, Z.; Shalabiea, O. M.

2018-01-01

In this work we present the first attempt of modelling the deuterium chemistry in the massive young protostellar core NGC 2264 CMM3. We investigated the sensitivity of this chemistry to the physical conditions in its surrounding environment. The results showed that deuteration, in the protostellar gas, is affected by variations in the core density, the amount of gas depletion onto grain surfaces, the CR ionisation rate, but it is insensitive to variations in the H2 ortho-to-para ratio. Our results, also, showed that deuteration is often enhanced in less-dense, partially depleted (<85%), or cores that are exerted to high CR ionisation rates (≥6.5×10^{-17} s^{-1}). However, in NGC 2264 CMM3, decreasing the amount of gas depleted onto grains and enhancing the CR ionisation rate are often overestimating the observed values in the core. The best fit time to observations occurs around (1-5) × 104 yrs for core densities in the range (1-5)×106 cm^{-3} with CR ionisation rate between (1.7-6.5)×10^{-17} s^{-1}. These values are in agreement with the results of the most recent theoretical chemical model of CMM3, and the time range of best fit is, also, in-line with the estimated age of young protostellar objects. We conclude that deuterium chemistry in protostellar cores is: (i) sensitive to variations in the physical conditions in its environment, (ii) insensitive to changes in the H2 ortho-to-para ratio. We also conclude that the core NGC 2264 CMM3 is in its early stages of chemical evolution with an estimated age of (1-5)×104 yrs.

Large-scale drivers of Caucasus climate variability in meteorological records and Mt El'brus ice cores

NASA Astrophysics Data System (ADS)

Kozachek, Anna; Mikhalenko, Vladimir; Masson-Delmotte, Valérie; Ekaykin, Alexey; Ginot, Patrick; Kutuzov, Stanislav; Legrand, Michel; Lipenkov, Vladimir; Preunkert, Susanne

2017-05-01

A 181.8 m ice core was recovered from a borehole drilled into bedrock on the western plateau of Mt El'brus (43°20'53.9'' N, 42°25'36.0'' E; 5115 m a.s.l.) in the Caucasus, Russia, in 2009 (Mikhalenko et al., 2015). Here, we report on the results of the water stable isotope composition from this ice core with additional data from the shallow cores. The distinct seasonal cycle of the isotopic composition allows dating by annual layer counting. Dating has been performed for the upper 126 m of the deep core combined with 20 m from the shallow cores. The whole record covers 100 years, from 2013 back to 1914. Due to the high accumulation rate (1380 mm w.e. year-1) and limited melting, we obtained isotopic composition and accumulation rate records with seasonal resolution. These values were compared with available meteorological data from 13 weather stations in the region and also with atmosphere circulation indices, back-trajectory calculations, and Global Network of Isotopes in Precipitation (GNIP) data in order to decipher the drivers of accumulation and ice core isotopic composition in the Caucasus region. In the warm season (May-October) the isotopic composition depends on local temperatures, but the correlation is not persistent over time, while in the cold season (November-April), atmospheric circulation is the predominant driver of the ice core's isotopic composition. The snow accumulation rate correlates well with the precipitation rate in the region all year round, which made it possible to reconstruct and expand the precipitation record at the Caucasus highlands from 1914 until 1966, when reliable meteorological observations of precipitation at high elevation began.

High performance carbon nanotube-Si core-shell wires with a rationally structured core for lithium ion battery anodes.

PubMed

Fan, Yu; Zhang, Qing; Lu, Congxiang; Xiao, Qizhen; Wang, Xinghui; Tay, Beng Kang

2013-02-21

Core-shell Si nanowires are very promising anode materials. Here, we synthesize vertically aligned carbon nanotubes (CNTs) with relatively large diameters and large inter-wire spacing as core wires and demonstrate a CNT-Si core-shell wire composite as a lithium ion battery (LIB) anode. Owing to the rationally engineered core structure, the composite shows good capacity retention and rate performance. The excellent performance is superior to most core-shell nanowires previously reported.

Evaluation of Ceramic Honeycomb Core Compression Behavior at Room Temperature

NASA Technical Reports Server (NTRS)

Bird, Richard K.; Lapointe, Thomas S.

2013-01-01

Room temperature flatwise compression tests were conducted on two varieties of ceramic honeycomb core specimens that have potential for high-temperature structural applications. One set of specimens was fabricated using strips of a commercially-available thin-gage "ceramic paper" sheet molded into a hexagonal core configuration. The other set was fabricated by machining honeycomb core directly from a commercially available rigid insulation tile material. This paper summarizes the results from these tests.

Masking of the circadian rhythms of heart rate and core temperature by the rest-activity cycle in man

NASA Technical Reports Server (NTRS)

Gander, Philippa H.; Connell, Linda J.; Graeber, R. Curtis

1986-01-01

Experiments were conducted to estimate the magnitude of the masking effect produced in humans by alternate periods of physical activity and rest or sleep on the circadian rhythms of heart rate and core temperature. The heart rate, rectal temperature, and nondominant wrist activity were monitored in 12 male subjects during 6 days of normal routine at home and during 6 days of controlled bed-rest regimen. The comparisons of averaged waveforms for the activity, heart rate, and temperature indicated that about 45 percent of the range of the circadian heart rate rhythm during normal routine and about 14 percent of the range of the circadian temperature rhythm were attributable to the effects of activity. The smaller effect of activity on the temperature rhythm may be partially attributable to the fact that core temperature is being more rigorously conserved than heart rate, at least during moderate exercise.

Laboratory Mid-frequency (Kilohertz) Range Seismic Property Measurements and X-ray CT Imaging of Fractured Sandstone Cores During Supercritical CO2 Injection

NASA Astrophysics Data System (ADS)

Nakagawa, S.; Kneafsey, T. J.; Chang, C.; Harper, E.

2014-12-01

During geological sequestration of CO2, fractures are expected to play a critical role in controlling the migration of the injected fluid in reservoir rock. To detect the invasion of supercritical (sc-) CO2 and to determine its saturation, velocity and attenuation of seismic waves can be monitored. When both fractures and matrix porosity connected to the fractures are present, wave-induced dynamic poroelastic interactions between these two different types of rock porosity—high-permeability, high-compliance fractures and low-permeability, low-compliance matrix porosity—result in complex velocity and attenuation changes of compressional waves as scCO2 invades the rock. We conducted core-scale laboratory scCO2 injection experiments on small (diameter 1.5 inches, length 3.5-4 inches), medium-porosity/permeability (porosity 15%, matrix permeability 35 md) sandstone cores. During the injection, the compressional and shear (torsion) wave velocities and attenuations of the entire core were determined using our Split Hopkinson Resonant Bar (short-core resonant bar) technique in the frequency range of 1-2 kHz, and the distribution and saturation of the scCO2 determined via X-ray CT imaging using a medical CT scanner. A series of tests were conducted on (1) intact rock cores, (2) a core containing a mated, core-parallel fracture, (3) a core containing a sheared core-parallel fracture, and (4) a core containing a sheared, core-normal fracture. For intact cores and a core containing a mated sheared fracture, injections of scCO2 into an initially water-saturated sample resulted in large and continuous decreases in the compressional velocity as well as temporary increases in the attenuation. For a sheared core-parallel fracture, large attenuation was also observed, but almost no changes in the velocity occurred. In contrast, a sample containing a core-normal fracture exhibited complex behavior of compressional wave attenuation: the attenuation peaked as the leading edge of the scCO2 approached the fracture; followed by an immediate drop as scCO2 invaded the fracture; and by another, gradual increase as the scCO2 infiltrated into the other side of the fracture. The compressional wave velocity declined monotonically, but the rate of velocity decrease changed with the changes in attenuation.

[Change of citizen's expectations for health activity in transition to a "Core City": focus on newly established public health centers].

PubMed

Hoshiko, Michiko; Hara, Kunio; Ishitake, Tatsuya

2010-01-01

This article aims to predict the future course of city administration and public health centers through clarifying the actual state and local residents' expectations of new public health centers on becoming a "Core City". Online questionnaire surveys targeting Kurume City residents were conducted in March 2008 (before becoming a Core City) and in October 2008, six months after becoming a Core City. Questions involved awareness of the Core City concept and the expectations for administration of the Core City and its new public health centers. The recognition rate for the Core City concept was 62.6% in the first questionnaire survey and 78.9% in the second survey, demonstrating a significant increase (P < 0.001). The expectations for the Core City centered on "Vitalization of the city" in both surveys. However, in the second survey results, "Nothing in particular" accounted for 81.2% of the responses for what the residents felt as a change after becoming a Core City. On the other hand, "Vitalization of the city" recorded 5.5% for the same question, showing a low rate. "Health promotion, Cancer check-ups, and Vaccination" were the most commonly chosen responses regarding expectations of the new public health centers in both surveys, accounting for approximately 30%. Nonetheless, the response to a question asking about actual utilization of the public health centers revealed a high rate of 83.4% for "Nothing in particular" in the second survey result. The recognition rate for the "Health Promotional Members" system implemented by the Kurume City public health centers from 2007 was a low 6.5%. Furthermore, the responses to the "District-Assigned Public Health Service" system to be introduced from 2009 were: In favor 52.6%, Opposed 3.0%, and Neither 44.3%. Although residents' expectations of public health centers are high, the surveys revealed that the health promotional activities provided by the public health centers were not fully utilized. In the future, the recognition rate of the "District-Assigned Public Health Service" starting in 2009 should be improved as quickly as possible to enhance the support system to accommodate individual health needs.

Impact compressive and bending behaviour of rocks accompanied by electromagnetic phenomena.

PubMed

Kobayashi, Hidetoshi; Horikawa, Keitaro; Ogawa, Kinya; Watanabe, Keiko

2014-08-28

It is well known that electromagnetic phenomena are often observed preceding earthquakes. However, the mechanism by which these electromagnetic waves are generated during the fracture and deformation of rocks has not been fully identified. Therefore, in order to examine the relationship between the electromagnetic phenomena and the mechanical properties of rocks, uniaxial compression and three-point bending tests for two kinds of rocks with different quartz content, granite and gabbro, have been carried out at quasi-static and dynamic rates. Especially, in the bending tests, pre-cracked specimens of granite were also tested. Using a split Hopkinson pressure bar and a ferrite-core antenna in close proximity to the specimens, both the stress-strain (load-displacement) curve and simultaneous electromagnetic wave magnitude were measured. It was found that the dynamic compressive and bending strengths and the stress increase slope of both rocks were higher than those observed in static tests; therefore, there is a strain-rate dependence in their strength and stress increase rate. It was found from the tests using the pre-cracked bending specimens that the intensity of electromagnetic waves measured during crack extension increased almost proportionally to the increase of the maximum stress intensity factor of specimens. This tendency was observed in both the dynamic and quasi-static three-point bending tests for granite. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Single rotating stars and the formation of bipolar planetary nebula

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

García-Segura, G.; Villaver, E.; Langer, N.

2014-03-10

We have computed new stellar evolution models that include the effects of rotation and magnetic torques under different hypotheses. The goal is to test whether a single star can sustain the rotational velocities needed in the envelope for magnetohydrodynamical(MHD) simulations to shape bipolar planetary nebulae (PNe) when high mass-loss rates take place. Stellar evolution models with main sequence masses of 2.5 and 5 M {sub ☉} and initial rotational velocities of 250 km s{sup –1} have been followed through the PNe formation phase. We find that stellar cores have to be spun down using magnetic torques in order to reproducemore » the rotation rates observed for white dwarfs. During the asymptotic giant branch phase and beyond, the magnetic braking of the core has a practically null effect on increasing the rotational velocity of the envelope since the stellar angular momentum is efficiently removed by the wind. We have also tested the best possible case scenarios in rather non-physical contexts to give enough angular momentum to the envelope. We find that we cannot get the envelope of a single star to rotate at the speeds needed for MHD simulations to form bipolar PNe. We conclude that single stellar rotators are unlikely to be the progenitors of bipolar PNe under the current MHD model paradigm.« less

Three nested randomized controlled trials of peer-only or multiple stakeholder group feedback within Delphi surveys during core outcome and information set development.

PubMed

Brookes, Sara T; Macefield, Rhiannon C; Williamson, Paula R; McNair, Angus G; Potter, Shelley; Blencowe, Natalie S; Strong, Sean; Blazeby, Jane M

2016-08-17

Methods for developing a core outcome or information set require involvement of key stakeholders to prioritise many items and achieve agreement as to the core set. The Delphi technique requires participants to rate the importance of items in sequential questionnaires (or rounds) with feedback provided in each subsequent round such that participants are able to consider the views of others. This study examines the impact of receiving feedback from different stakeholder groups, on the subsequent rating of items and the level of agreement between stakeholders. Randomized controlled trials were nested within the development of three core sets each including a Delphi process with two rounds of questionnaires, completed by patients and health professionals. Participants rated items from 1 (not essential) to 9 (absolutely essential). For round 2, participants were randomized to receive feedback from their peer stakeholder group only (peer) or both stakeholder groups separately (multiple). Decisions as to which items to retain following each round were determined by pre-specified criteria. Whilst type of feedback did not impact on the percentage of items for which a participant subsequently changed their rating, or the magnitude of change, it did impact on items retained at the end of round 2. Each core set contained discordant items retained by one feedback group but not the other (3-22 % discordant items). Consensus between patients and professionals in items to retain was greater amongst those receiving multiple group feedback in each core set (65-82 % agreement for peer-only feedback versus 74-94 % for multiple feedback). In addition, differences in round 2 scores were smaller between stakeholder groups receiving multiple feedback than between those receiving peer group feedback only. Variability in item scores across stakeholders was reduced following any feedback but this reduction was consistently greater amongst the multiple feedback group. In the development of a core outcome or information set, providing feedback within Delphi questionnaires from all stakeholder groups separately may influence the final core set and improve consensus between the groups. Further work is needed to better understand how participants rate and re-rate items within a Delphi process. The three randomized controlled trials reported here were each nested within the development of a core information or outcome set to investigate processes in core outcome and information set development. Outcomes were not health-related and therefore trial registration was not applicable.

Tretinoin-loaded lipid-core nanocapsules decrease reactive oxygen species levels and improve bovine embryonic development during in vitro oocyte maturation.

PubMed

Lucas, Caroline Gomes; Remião, Mariana Härter; Komninou, Eliza Rossi; Domingues, William Borges; Haas, Cristina; Leon, Priscila Marques Moura de; Campos, Vinicius Farias; Ourique, Aline; Guterres, Silvia S; Pohlmann, Adriana R; Basso, Andrea Cristina; Seixas, Fabiana Kömmling; Beck, Ruy Carlos Ruver; Collares, Tiago

2015-12-01

In vitro oocyte maturation (IVM) protocols can be improved by adding chemical supplements to the culture media. Tretinoin is considered an important retinoid in embryonic development and its association with lipid-core nanocapsules (TTN-LNC) represents an innovative way of improving its solubility, and chemical stability, and reducing its toxicity. The effects of supplementing IVM medium with TTN-LNC was evaluated by analyzing production of reactive oxygen species (ROS), S36-phosphorilated-p66Shc levels and caspase activity in early embryonic development, and expression of apoptosis and pluripotency genes in blastocysts. The lowest concentration tested (0.25μM) of TTN-LNC generated higher blastocyst rate, lower ROS production and S36-p66Shc amount. Additionally, expression of BAX and SHC1 were lower in both non-encapsulated tretinoin (TTN) and TTN-LNC-treated groups. Nanoencapsulation allowed the use of smaller concentrations of tretinoin to supplement IVM medium thus reducing toxic effects related with its use, decreasing ROS levels and apoptose frequency, and improving the blastocyst rates. Copyright © 2015 Elsevier Inc. All rights reserved.

Modeling and Detection of Ice Particle Accretion in Aircraft Engine Compression Systems

NASA Technical Reports Server (NTRS)

May, Ryan D.; Simon, Donald L.; Guo, Ten-Huei

2012-01-01

The accretion of ice particles in the core of commercial aircraft engines has been an ongoing aviation safety challenge. While no accidents have resulted from this phenomenon to date, numerous engine power loss events ranging from uneventful recoveries to forced landings have been recorded. As a first step to enabling mitigation strategies during ice accretion, a detection scheme must be developed that is capable of being implemented on board modern engines. In this paper, a simple detection scheme is developed and tested using a realistic engine simulation with approximate ice accretion models based on data from a compressor design tool. These accretion models are implemented as modified Low Pressure Compressor maps and have the capability to shift engine performance based on a specified level of ice blockage. Based on results from this model, it is possible to detect the accretion of ice in the engine core by observing shifts in the typical sensed engine outputs. Results are presented in which, for a 0.1 percent false positive rate, a true positive detection rate of 98 percent is achieved.

Self-immunity microcapsules for corrosion protection of steel bar in reinforced concrete

NASA Astrophysics Data System (ADS)

Wang, Yanshuai; Fang, Guohao; Ding, Weijian; Han, Ningxu; Xing, Feng; Dong, Biqin

2015-12-01

A novel microcapsule-based self-immunity system for reinforced concrete is proposed. Its feasibility for hindering the corrosion of steel rebar by means of lifting the threshold value of [Cl-]/[OH-] is discussed. Precisely controlled release behavior enables corrosion protection in the case of depassivation. The release process is characterized over a designated range of pH values, and its release characteristics of the microcapsules, triggered by decreasing pH value, are captured by observing that the core crystals are released when exposed to a signal (stimulus). The aim of corrosion protection of steel bar is achieved through the constantly-stabilized passive film, and its stability is promoted using continuous calcium hydroxide released from the microcapsule, restoring alkaline conditions. The test results exhibited that the release process of the microcapsules is a function of time. Moreover, the release rate of core materials could interact with environmental pH value, in which the release rate is found to increase remarkably with decreasing pH value, but is inhibited by high pH levels.

Self-immunity microcapsules for corrosion protection of steel bar in reinforced concrete.

PubMed

Wang, Yanshuai; Fang, Guohao; Ding, Weijian; Han, Ningxu; Xing, Feng; Dong, Biqin

2015-12-17

A novel microcapsule-based self-immunity system for reinforced concrete is proposed. Its feasibility for hindering the corrosion of steel rebar by means of lifting the threshold value of [Cl(-)]/[OH(-)] is discussed. Precisely controlled release behavior enables corrosion protection in the case of depassivation. The release process is characterized over a designated range of pH values, and its release characteristics of the microcapsules, triggered by decreasing pH value, are captured by observing that the core crystals are released when exposed to a signal (stimulus). The aim of corrosion protection of steel bar is achieved through the constantly-stabilized passive film, and its stability is promoted using continuous calcium hydroxide released from the microcapsule, restoring alkaline conditions. The test results exhibited that the release process of the microcapsules is a function of time. Moreover, the release rate of core materials could interact with environmental pH value, in which the release rate is found to increase remarkably with decreasing pH value, but is inhibited by high pH levels.

Nanoscale Engineering of Efficient Oxygen Reduction Electrocatalysts by Tailoring the Local Chemical Environment of Pt Surface Sites

DOE PAGES

Cleve, Tim Van; Moniri, Saman; Belok, Gabrielle; ...

2016-11-16

The oxygen reduction reaction is the limiting half-reaction in hydrogen fuel cells. While Pt is the most active single component electrocatalyst for the reaction, it is hampered by high cost and low reaction rates. Most research to overcome these limitations has focused on Pt/3d alloys, which offer higher rates and lower cost. Here, we have synthesized, characterized, and tested alloy materials belonging to a multilayer family of electrocatalysts. The multilayer alloy materials contain an AuCu alloy core of precise composition, surrounded by Au layers and covered by a catalytically active Pt surface layer. Their performance relative to that of themore » commercial Pt standards reaches up to 4 times improved area-specific activity. Characterization studies support the hypothesis that the activity improvement originates from a combination of Au–Pt ligand effects and local strain effects manipulated through the AuCu alloy core. The approach we present to control the strain and ligand effects in the synthesis of Pt-based alloys for the ORR is very general and could lead to promising alloy materials.« less

Comparison of Series of Vugs and Non-vuggy Synthetic Porous Media on Formation Damage

NASA Astrophysics Data System (ADS)

Khan, H.; DiCarlo, D. A.; Prodanovic, M.

2017-12-01

Produced water reinjection (PWRI) is an established cost-effective oil field practice where produced water is injected without any cleanup, for water flooding or disposal. Resultantly the cost of fresh injection fluid and/or processing produced water is saved. A common problem with injection of unprocessed water is formation damage in the near injection zone due to solids (fines) entrapment, causing a reduction in permeability and porosity of the reservoir. Most studies have used homogeneous porous media with unimodal grain sizes, while real world porous media often has a wide range of pores, up to and including vugs in carbonaceous rocks. Here we fabricate a series of vugs in synthetic porous media by sintering glass beads with large dissolvable inclusions. The process is found to be repeatable, allowing a similar vug configuration to be tested for different flow conditions. Bi-modal glass bead particles (25 & 100 micron) are injected at two different flow rates and three different injection concentrations. Porosity, permeability and effluent concentration are determined using CT scanning, pressure measurements and particle counting (Coulter counter), respectively. Image analysis is performed on the CT images to determine the change in vug size for each flow condition. We find that for the same flow conditions, heterogeneous media with series of vugs have an equal or greater permeability loss compared to homogeneous porous media. A significant change in permeability is observed at the highest concentration and flow rate as more particles approach the filter quickly, resulting in a greater loss in permeability in the lower end of the core. Image analysis shows the highest loss in vug size occurs at the low flow rate and highest concentration. The lower vug is completely blocked for this flow case. For all flow cases lower values of porosity are observed after the core floods. At low flow rate and medium concentration, a drastic loss in porosity is observed in the lower part of the core, after the vuggy zone. This trough is also distinctly clear in the homogeneous core for the same flow conditions. This study focuses on understanding the effect of pore heterogeneity on formation damage. We conclude that more damage is done deeper in vuggy formations at high flow rates, resulting in shorter injection cycle prior to clean up.

HTGR fuels and core development program. Quarterly progress report for the period ending August 31, 1975

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

None

1975-09-30

Studies of reactions between core materials and coolant impurities, basic fission product transport mechanisms, core graphite development and testing, the development and testing of recyclable fuel systems, and physics and fuel management studies are described. Materials studies include irradiation capsule tests of both fuel and graphite. Experimental procedures and results are discussed and, where appropriate, the data are presented in tables, graphs, and photographs. (auth)

TRAC-PD2 posttest analysis of CCTF Test C1-16 (Run 025). [Cylindrical Core Test Facility

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

Sugimoto, J.

The TRAC-PD2 code version was used to analyze CCTF Test C1-16 (Run 025). The results indicate that the core heater rod temperatures, the liquid mass in the vessel, and differential pressures in the primary loop are predicted well, but the void fraction distribution in the core and water accumulation in the upper plenum are not in good agreement with the data.

13.1 Foot Diameter Fluted-Core Sandwich Composite Test Article

NASA Image and Video Library

2013-09-26

White light shape and measurement of a 13.1 Foot diameter fluted-core sandwich composite test article designed by LaRC and fabricated by Boeing Under Space Act Agreement SAA1-737, Annex 14. to be tested in LaRC's combined Loads Testing System (COLTS).

13.1 Foot Diameter Fluted-Core Sandwich Composite Test Article

NASA Image and Video Library

2013-09-25

White light shape and measurement of a 13.1 Foot diameter fluted-core sandwich composite test article designed by LaRC and fabricated by Boeing Under Space Act Agreement SAA1-737, Annex 14. to be tested in LaRC's combined Loads Testing System (COLTS).

Development of a single-shot CCD-based data acquisition system for time-resolved X-ray photoelectron spectroscopy at an X-ray free-electron laser facility

PubMed Central

Oura, Masaki; Wagai, Tatsuya; Chainani, Ashish; Miyawaki, Jun; Sato, Hiromi; Matsunami, Masaharu; Eguchi, Ritsuko; Kiss, Takayuki; Yamaguchi, Takashi; Nakatani, Yasuhiro; Togashi, Tadashi; Katayama, Tetsuo; Ogawa, Kanade; Yabashi, Makina; Tanaka, Yoshihito; Kohmura, Yoshiki; Tamasaku, Kenji; Shin, Shik; Ishikawa, Tetsuya

2014-01-01

In order to utilize high-brilliance photon sources, such as X-ray free-electron lasers (XFELs), for advanced time-resolved photoelectron spectroscopy (TR-PES), a single-shot CCD-based data acquisition system combined with a high-resolution hemispherical electron energy analyzer has been developed. The system’s design enables it to be controlled by an external trigger signal for single-shot pump–probe-type TR-PES. The basic performance of the system is demonstrated with an offline test, followed by online core-level photoelectron and Auger electron spectroscopy in ‘single-shot image’, ‘shot-to-shot image (image-to-image storage or block storage)’ and ‘shot-to-shot sweep’ modes at soft X-ray undulator beamline BL17SU of SPring-8. In the offline test the typical repetition rate for image-to-image storage mode has been confirmed to be about 15 Hz using a conventional pulse-generator. The function for correcting the shot-to-shot intensity fluctuations of the exciting photon beam, an important requirement for the TR-PES experiments at FEL sources, has been successfully tested at BL17SU by measuring Au 4f photoelectrons with intentionally controlled photon flux. The system has also been applied to hard X-ray PES (HAXPES) in ‘ordinary sweep’ mode as well as shot-to-shot image mode at the 27 m-long undulator beamline BL19LXU of SPring-8 and also at the SACLA XFEL facility. The XFEL-induced Ti 1s core-level spectrum of La-doped SrTiO3 is reported as a function of incident power density. The Ti 1s core-level spectrum obtained at low power density is consistent with the spectrum obtained using the synchrotron source. At high power densities the Ti 1s core-level spectra show space-charge effects which are analysed using a known mean-field model for ultrafast electron packet propagation. The results successfully confirm the capability of the present data acquisition system for carrying out the core-level HAXPES studies of condensed matter induced by the XFEL. PMID:24365935

Advanced Marketing Core Curriculum. Test Items and Assessment Techniques.

ERIC Educational Resources Information Center

Smith, Clifton L.; And Others

This document contains duties and tasks, multiple-choice test items, and other assessment techniques for Missouri's advanced marketing core curriculum. The core curriculum begins with a list of 13 suggested textbook resources. Next, nine duties with their associated tasks are given. Under each task appears one or more citations to appropriate…

Heat Pipe Reactor Dynamic Response Tests: SAFE-100 Reactor Core Prototype

NASA Technical Reports Server (NTRS)

Bragg-Sitton, Shannon M.

2005-01-01

The SAFE-I00a test article at the NASA Marshall Space Flight Center was used to simulate a variety of potential reactor transients; the SAFEl00a is a resistively heated, stainless-steel heat-pipe (HP)-reactor core segment, coupled to a gas-flow heat exchanger (HX). For these transients the core power was controlled by a point kinetics model with reactivity feedback based on core average temperature; the neutron generation time and the temperature feedback coefficient are provided as model inputs. This type of non-nuclear test is expected to provide reasonable approximation of reactor transient behavior because reactivity feedback is very simple in a compact fast reactor (simple, negative, and relatively monotonic temperature feedback, caused mostly by thermal expansion) and calculations show there are no significant reactivity effects associated with fluid in the HP (the worth of the entire inventory of Na in the core is .

Effect of core strength training on dynamic balance and agility in adolescent badminton players.

PubMed

Ozmen, Tarik; Aydogmus, Mert

2016-07-01

The aim of the present study was to investigate effect of core strength training (CST) on core endurance, dynamic balance and agility in adolescent badminton players. Twenty adolescent (age = 10.8 ± 0.3 years; height = 140.6 ± 4.4 cm, weight = 33.9 ± 5.8 kg) badminton players were randomly divided into two groups as training group (TG) and control (CG) group. All subjects were evaluated with Star Excursion Balance Test (SEBT), Illinois Agility Test, and the core endurance tests. The TG completed CST twice a week, for 6 weeks. There were significant increases in (p < 0.05) directions of SEBT and core endurance tests (p < 0.05). However, no significant change was observed for agility (p > 0.05). The CST resulted in significant gains in directions of the SEBT and core endurances in adolescent badminton players, but not in agility. Copyright © 2015 Elsevier Ltd. All rights reserved.

Isothermic and fixed intensity heat acclimation methods induce similar heat adaptation following short and long-term timescales.

PubMed

Gibson, Oliver R; Mee, Jessica A; Tuttle, James A; Taylor, Lee; Watt, Peter W; Maxwell, Neil S

2015-01-01

Heat acclimation requires the interaction between hot environments and exercise to elicit thermoregulatory adaptations. Optimal synergism between these parameters is unknown. Common practise involves utilising a fixed workload model where exercise prescription is controlled and core temperature is uncontrolled, or an isothermic model where core temperature is controlled and work rate is manipulated to control core temperature. Following a baseline heat stress test; 24 males performed a between groups experimental design performing short term heat acclimation (STHA; five 90 min sessions) and long term heat acclimation (LTHA; STHA plus further five 90 min sessions) utilising either fixed intensity (50% VO2peak), continuous isothermic (target rectal temperature 38.5 °C for STHA and LTHA), or progressive isothermic heat acclimation (target rectal temperature 38.5 °C for STHA, and 39.0 °C for LTHA). Identical heat stress tests followed STHA and LTHA to determine the magnitude of adaptation. All methods induced equal adaptation from baseline however isothermic methods induced adaptation and reduced exercise durations (STHA = -66% and LTHA = -72%) and mean session intensity (STHA = -13% VO2peak and LTHA = -9% VO2peak) in comparison to fixed (p < 0.05). STHA decreased exercising heart rate (-10 b min(-1)), core (-0.2 °C) and skin temperature (-0.51 °C), with sweat losses increasing (+0.36 Lh(-1)) (p<0.05). No difference between heat acclimation methods, and no further benefit of LTHA was observed (p > 0.05). Only thermal sensation improved from baseline to STHA (-0.2), and then between STHA and LTHA (-0.5) (p<0.05). Both the continuous and progressive isothermic methods elicited exercise duration, mean session intensity, and mean T(rec) analogous to more efficient administration for maximising adaptation. Short term isothermic methods are therefore optimal for individuals aiming to achieve heat adaptation most economically, i.e. when integrating heat acclimation into a pre-competition taper. Fixed methods may be optimal for military and occupational applications due to lower exercise intensity and simplified administration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Genesis of Pre-Hurricane Felix (2007). Part 2; Warm Core Formation, Precipitation Evolution, and Predictability

NASA Technical Reports Server (NTRS)

Wang, zhuo; Montgomery M. T.; Dunkerton, T. J.

2010-01-01

This is the second of a two-part study examining the simulated formation of Atlantic Hurricane Felix (2007) in a cloud-representing framework. Here several open issues are addressed concerning the formation of the storm's warm core, the evolution and respective contribution of stratiform versus convective precipitation within the parent wave's pouch, and the sensitivity of the development pathway reported in Part I to different model physics options and initial conditions. All but one of the experiments include ice microphysics as represented by one of several parameterizations, and the partition of convective versus stratiform precipitation is accomplished using a standard numerical technique based on the high-resolution control experiment. The transition to a warm-core tropical cyclone from an initially cold-core, lower tropospheric wave disturbance is analyzed first. As part of this transformation process, it is shown that deep moist convection is sustained near the pouch center. Both convective and stratiform precipitation rates increase with time. While stratiform precipitation occupies a larger area even at the tropical storm stage, deep moist convection makes a comparable contribution to the total rain rate at the pregenesis stage, and a larger contribution than stratiform processes at the storm stage. The convergence profile averaged near the pouch center is found to become dominantly convective with increasing deep moist convective activity there. Low-level convergence forced by interior diabatic heating plays a key role in forming and intensifying the near-surface closed circulation, while the midlevel convergence associated with stratiform precipitation helps to increase the midlevel circulation and thereby contributes to the formation and upward extension of a tropospheric-deep cyclonic vortex. Sensitivity tests with different model physics options and initial conditions demonstrate a similar pregenesis evolution. These tests suggest that the genesis location of a tropical storm is largely controlled by the parent wave's critical layer, whereas the genesis time and intensity of the protovortex depend on the details of the mesoscale organization, which is less predictable. Some implications of the findings are discussed.

Amino acid epimerization implies rapid sedimentation rates in Arctic Ocean cores

USGS Publications Warehouse

Sejrup, H.P.; Miller, G.H.; Brigham-Grette, J.; Lovlie, R.; Hopkins, D.

1984-01-01

The palaeooceanography of the Arctic Ocean is less well known than any other ocean basin, due to difficulties in obtaining cores and in providing a secure chronological framework for those cores that have been raised. Most recent investigators have suggested that low sedimentation rates (0.05-0.1 cm kyr-1) have characterized the deep basins over the past 5 Myr (refs 1,2) despite the glacial-marine character of the sediment and proximity to major centres of shelf glaciation. These calculations have been primarily based on the down-core pattern in the inclination of magnetic minerals, supported by uranium-series, 14C and micropalaeontological evidence. Here we analyse amino acid diagnesis in foraminifera from two gravity cores raised from the floor of the Arctic Ocean, our results suggest that these cores span <200 kyr., conflicting with the earlier estimate of 3 Myr based on palaeomagnetic data. The chronology of other Arctic Ocean cores and previous palaeoenvironmental interpretations need re-evaluation. ?? 1984 Nature Publishing Group.

TRAC analyses for CCTF and SCTF tests and UPTF design/operation. [Cylindrical Core Test Facility; Slab Core Test Facility; Upper Plenum Test Facility

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

Spore, J.W.; Cappiello, M.W.; Dotson, P.J.

The analytical support in 1985 for Cylindrical Core Test Facility (CCTF), Slab Core Test Facility (SCTF), and Upper Plenum Test Facility (UPTF) tests involves the posttest analysis of 16 tests that have already been run in the CCTF and the SCTF and the pretest analysis of 3 tests to be performed in the UPTF. Posttest analysis is used to provide insight into the detailed thermal-hydraulic phenomena occurring during the refill and reflood tests performed in CCTF and SCTF. Pretest analysis is used to ensure that the test facility is operated in a manner consistent with the expected behavior of anmore » operating full-scale plant during an accident. To obtain expected behavior of a plant during an accident, two plant loss-of-coolant-accident (LOCA) calculations were performed: a 200% cold-leg-break LOCA calculation for a 2772 MW(t) Babcock and Wilcox plant and a 200% cold-leg-break LOCA calculation for a 3315 MW(t) Westinghouse plant. Detailed results are presented for several CCTF UPI tests and the Westinghouse plant analysis.« less

Implementation of testing equipment for asphalt materials.

DOT National Transportation Integrated Search

2009-05-01

Three new automated methods for related asphalt testing were evaluated under this study in an effort to save time and reduce variability in testing. The Therymolyne SSDetect, Instrotek CoreLok and Instrotek CoreDry devices were evaluated throughout t...

Implementation of Testing Equipment for Asphalt Materials

DOT National Transportation Integrated Search

2009-05-01

Three new automated methods for related asphalt testing were evaluated under this study in an effort to save time and reduce variability in testing. The Therymolyne SSDetect, Instrotek CoreLok and Instrotek CoreDry devices were evaluated throughout t...

Arctic Circle Traverse 2010 (ACT-10): South East Greenland snow accumulation variability from firn coring and ice sounding radar

NASA Astrophysics Data System (ADS)

Forster, R. R.; Miege, C.; Box, J. E.; McConnell, J.; Spikes, V. B.; Burgess, E. W.

2010-12-01

The Greenland Ice Sheet plays an important role in Earth’s climate system evolution. The snow accumulation rate is the largest single mass budget term. With only 14% of the ice sheet area, Southeast Greenland contains the highest accumulation rates, accounting for one third of the total snow accumulation and annual variability. The high accumulation rates have made the region less desirable for long climate record ice cores and therefore, contain relatively very few in situ measurements to constrain the ice sheet mass budget. We present annual snow accumulation rates from the Arctic Circle Traverse 2010 (ACT-10). During April and May 2010 we acquired three 50 m firn cores connected by surface-based 400 MHz ground penetrating radar (GPR) in Southeast Greenland. The traverse repeated and extended the original Arctic Circle Traverse in 2004 (Spikes et al., 2004). Dating is achieved using geochemical analysis of the cores to identify isochronal layers detected by the GPR yielding annual accumulation estimates along the traverse between the core sites. The 300 km ACT-10 GPR snowmobile traverse extended the ACT-04 path 80 km to the lowest elevation core site at 1776 m. Meanwhile, airborne radars, operating as part of NASA’s Operation IceBridge also acquired data over the full length of the ACT-10 path, simultaneously with a portion of the traverse and within days for the remaining segments. The IceBridge and ACT-10 data are to be combined in a calibration effort such that snow accumulation rates may be mapped elsewhere in Greenland and even in Antarctica.

Pricing the Services of Scientific Cores. Part I: Charging Subsidized and Unsubsidized Users.

ERIC Educational Resources Information Center

Fife, Jerry; Forrester, Robert

2002-01-01

Explaining that scientific cores at research institutions support shared resources and facilities, discusses devising a method of charging users for core services and controlling and managing the rates. Proposes the concept of program-based management to cover sources of core support that are funding similar work. (EV)

Validation of the MCNP computational model for neutron flux distribution with the neutron activation analysis measurement

NASA Astrophysics Data System (ADS)

Tiyapun, K.; Chimtin, M.; Munsorn, S.; Somchit, S.

2015-05-01

The objective of this work is to demonstrate the method for validating the predication of the calculation methods for neutron flux distribution in the irradiation tubes of TRIGA research reactor (TRR-1/M1) using the MCNP computer code model. The reaction rate using in the experiment includes 27Al(n, α)24Na and 197Au(n, γ)198Au reactions. Aluminium (99.9 wt%) and gold (0.1 wt%) foils and the gold foils covered with cadmium were irradiated in 9 locations in the core referred to as CT, C8, C12, F3, F12, F22, F29, G5, and G33. The experimental results were compared to the calculations performed using MCNP which consisted of the detailed geometrical model of the reactor core. The results from the experimental and calculated normalized reaction rates in the reactor core are in good agreement for both reactions showing that the material and geometrical properties of the reactor core are modelled very well. The results indicated that the difference between the experimental measurements and the calculation of the reactor core using the MCNP geometrical model was below 10%. In conclusion the MCNP computational model which was used to calculate the neutron flux and reaction rate distribution in the reactor core can be used for others reactor core parameters including neutron spectra calculation, dose rate calculation, power peaking factors calculation and optimization of research reactor utilization in the future with the confidence in the accuracy and reliability of the calculation.

Physical and Biological Regulation of Carbon Sequestration in Tidal Marshes

NASA Astrophysics Data System (ADS)

Morris, J. T.; Callaway, J.

2017-12-01

The rate of carbon sequestration in tidal marshes is regulated by complex feedbacks among biological and physical factors including the rate of sea-level rise (SLR), biomass production, tidal amplitude, and the concentration of suspended sediment. We used the Marsh Equilibrium Model (MEM) to explore the effects on C-sequestration across a wide range of permutations of these variables. C-sequestration increased with the rate of SLR to a maximum, then down to a vanishing point at higher SLR when marshes convert to mudflats. An acceleration in SLR will increase C-sequestration in marshes that can keep pace, but at high rates of SLR this is only possible with high biomass and suspended sediment concentrations. We found that there were no feasible solutions at SLR >13 mm/yr for permutations of variables that characterize the great majority of tidal marshes, i.e., the equilibrium elevation exists below the lower vertical limit for survival of marsh vegetation. The rate of SLR resulting in maximum C-sequestration varies with biomass production. C-sequestration rates at SLR=1 mm/yr averaged only 36 g C m-2 yr-1, but at the highest maximum biomass tested (5000 g/m2) the mean C-sequestration reached 399 g C m-2 yr-1 at SLR = 14 mm/yr. The empirical estimate of C-sequestration in a core dated 50-years overestimates the theoretical long-term rate by 34% for realistic values of decomposition rate and belowground production. The overestimate of the empirical method arises from the live and decaying biomass contained within the carbon inventory above the marker horizon, and overestimates were even greater for shorter surface cores.

Testing and Evaluation of the EOSDIS Core System: An ECS Science Advisor Proposal

NASA Technical Reports Server (NTRS)

Welch, Ronald M.; Christopher, Sundar A.

1997-01-01

The major goal of this project was to: 1) perform hands on testing of the evaluation packages, 2) provide feedback in the design of the EOSDIS Core System, and 3) test the effectiveness of the DAAC's by acquiring and testing remote sensing data sets.

Posttest TRAC-PD2/MOD1 predictions for FLECHT SEASET test 31504. [PWR

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

Booker, C.P.

TRAC-PD2/MOD1 is a publicly released version of TRAC that is used primarily to analyze large-break loss-of-coolant accidents in pressurized-water reactors (PWRs). TRAC-PD2 can calculate, among other things, reflood phenomena. TRAC posttest predictions are compared with test 31504 reflood data from the Full-Length Emergency Core Heat Transfer (FLECHT) System Effects and Separate Effects Tests (SEASET) facility. A false top-down quench is predicted near the top of the core and the subcooling is underpredicted at the bottom of the core. However, the overall TRAC predictions are good, especially near the center of the core.

Investigation of mechanical properties of hydrate-bearing pressure core sediments recovered from the Eastern Nankai Trough using transparent acrylic cell triaxial testing system (TACTT-system)

NASA Astrophysics Data System (ADS)

Yoneda, J.; Masui, A.; Konno, Y.; Jin, Y.; Kida, M.; Suzuki, K.; Nakatsuka, Y.; Tenma, N.; Nagao, J.

2014-12-01

Natural gas hydrate-bearing pressure core sediments have been sheared in compression using a newly developed Transparent Acrylic Cell Triaxial Testing (TACTT) system to investigate the geophysical and geomechanical behavior of sediments recovered from the deep seabed in the Eastern Nankai Trough, the first Japanese offshore production test region. The sediments were recovered by hybrid pressure core system (hybrid PCS) and pressure cores were cut by pressure core analysis tools (PCATs) on board. These pressure cores were transferred to the AIST Hokkaido centre and trimmed by pressure core non-destructive analysis tools (PNATs) for TACTT system which maintained the pressure and temperature conditions within the hydrate stability boundary, through the entire process of core handling from drilling to the end of laboratory testing. An image processing technique was used to capture the motion of sediment in a transparent acrylic cell, and digital photographs were obtained at every 0.1% of vertical strain during the test. Analysis of the optical images showed that sediments with 63% hydrate saturation exhibited brittle failure, although nonhydrate-bearing sediments exhibited ductile failure. In addition, the increase in shear strength with hydrate saturation increase of natural gas hydrate is in agreement with previous data from synthetic gas hydrate. This research was financially supported by the Research Consortium for Methane Hydrate Resources in Japan (MH21 Research Consortium) that carries out Japan's Methane Hydrate R&D Program by the Ministry of Economy, Trade and Industry (METI).

An update on the prevalence of HIV/AIDS in Bangladesh.

PubMed

Islam, M M; Karim, E; Mian, M A; Kristensen, S; Chowdhury, M R; Vermund, S H

1999-06-01

The National AIDS Committee was formed in 1985 to develop and support policies that prevent transmission of human immunodeficiency virus (HIV). In 1990, the Institute of Epidemiology, Disease Control and Research in the Ministry of Health began sero-surveillance for AIDS/HIV infection. Convenience sampling was conducted among prisoners, sailors, truckers, antenatal attendees, repatriated Bangladeshi workers, and brothel-based prostitutes in Dhaka. In 1994, commercial sex workers in other high-risk areas were included in surveillance activities. Among over 75,700 HIV tests through 1998, 119 have been confirmed positive for HIV. While the cumulative HIV prevalence rate was only 1.5/1,000 tests, it was significantly higher among men (p < 0.0001) than among women. The rates among men were as high as 28/1,000 tests in 1996 and 21/1,000 tests in 1997. Almost 50% of the reported HIV cases are from cities on the border of India and Myanmar. It is anticipated that HIV transmission will increase further given the high prevalence of risk behaviors, core high-risk groups, and extreme poverty.

Clinical audit of core podiatry treatment in the NHS.

PubMed

Farndon, Lisa; Barnes, Andrew; Littlewood, Keith; Harle, Justine; Beecroft, Craig; Burnside, Jaclyn; Wheeler, Tracey; Morris, Selwyn; Walters, Stephen J

2009-03-13

Core podiatry involves treatment of the nails, corns and callus and also giving footwear and foot health advice. Though it is an integral part of current podiatric practice little evidence is available to support its efficacy in terms of research and audit data. This information is important in order to support the current NHS commissioning process where services are expected to provide data on standards including outcomes. This study aimed to increase the evidence base for this area of practice by conducting a multi-centre audit in 8 NHS podiatry departments over a 1-year period. The outcome measure used in this audit was the Podiatry Health Questionnaire which is a self completed short measure of foot health including a pain visual analogue scale and a section for the podiatrist to rate an individual's foot health based on their podiatric problems. The patient questionnaire was completed by individuals prior to receiving podiatry care and then 2 weeks after treatment to assess the effect of core podiatry in terms of pain and foot health. 1047 patients completed both questionnaires, with an age range from 26-95 years and a mean age of 72.9 years. The podiatrists clinical rating at baseline showed 75% of patients had either slight or moderate podiatric problems. The differences in questionnaire and visual analogue scores before and after treatment were determined according to three categories - better, same, worse and 75% of patients' scores either remained the same or improved after core podiatry treatment. A student t-test showed a statistical significant difference in pre and post treatment scores where P < 0.001, though the confidence interval indicated that the improvement was relatively small. Core podiatry has been shown to sustain or improve foot health and pain in 75% of the patients taking part in the audit. Simple outcome measures including pain scales should be used routinely in podiatric practice to assess the affect of different aspects of treatments and improve the evidence base for podiatry.

Measurement and simulation of thermal neutron flux distribution in the RTP core

NASA Astrophysics Data System (ADS)

Rabir, Mohamad Hairie B.; Jalal Bayar, Abi Muttaqin B.; Hamzah, Na'im Syauqi B.; Mustafa, Muhammad Khairul Ariff B.; Karim, Julia Bt. Abdul; Zin, Muhammad Rawi B. Mohamed; Ismail, Yahya B.; Hussain, Mohd Huzair B.; Mat Husin, Mat Zin B.; Dan, Roslan B. Md; Ismail, Ahmad Razali B.; Husain, Nurfazila Bt.; Jalil Khan, Zareen Khan B. Abdul; Yakin, Shaiful Rizaide B. Mohd; Saad, Mohamad Fauzi B.; Masood, Zarina Bt.

2018-01-01

The in-core thermal neutron flux distribution was determined using measurement and simulation methods for the Malaysian’s PUSPATI TRIGA Reactor (RTP). In this work, online thermal neutron flux measurement using Self Powered Neutron Detector (SPND) has been performed to verify and validate the computational methods for neutron flux calculation in RTP calculations. The experimental results were used as a validation to the calculations performed with Monte Carlo code MCNP. The detail in-core neutron flux distributions were estimated using MCNP mesh tally method. The neutron flux mapping obtained revealed the heterogeneous configuration of the core. Based on the measurement and simulation, the thermal flux profile peaked at the centre of the core and gradually decreased towards the outer side of the core. The results show a good agreement (relatively) between calculation and measurement where both show the same radial thermal flux profile inside the core: MCNP model over estimation with maximum discrepancy around 20% higher compared to SPND measurement. As our model also predicts well the neutron flux distribution in the core it can be used for the characterization of the full core, that is neutron flux and spectra calculation, dose rate calculations, reaction rate calculations, etc.

Encapsulation of Anticancer Drugs (5-Fluorouracil and Paclitaxel) into Polycaprolactone (PCL) Nanofibers and In Vitro Testing for Sustained and Targeted Therapy

PubMed Central

Iqbal, Sakib; Rashid, Mohammad H.; Arbab, Ali S.; Khan, Mujibur

2017-01-01

We report a continuous nanoscale encapsulation of cancer drugs 5-Fluorouracil (FU) and Paclitaxel into biocompatible polycaprolactone (PCL) nanofibers (NFs) using core-sheath electrospinning process. A high potential electric field of 19–23.2 kV was used to draw a compound solution jet from a specialized coaxial spinneret. Using of DMF in both core and Sheath resulted in NFs within 50–160 nm along with large beaded structures. Addition of Trichloromethane (TCM) or Trifluoroethanol (TFE) in sheath turned NFs in more uniform and thin fiber structure. The diameter range for paclitaxel encapsulated fibers was 22–90 nm with encapsulation efficiency of 77.5% and the amount of drug was only 4 to 5% of sheath polymer. Addition of PVA within core resulted drug nanocrystal formation outside of sheath and poor encapsulation efficiency (52%) with rapid initial release (52–53%) in first 3 days. Drug release test of NFs in different pH exhibited increase of release rate with the decrease of media pH. In-vitro cell viability test with FU encapsulated NFs in human prostatic cancer PC3 cells exhibited 38% alive cells at 5 μM concentration while in pristine FU 43% cells were alive. Paclitaxel encapsulated NFs with breast cancer cells also exhibited increased efficacy in comparison to pristine anticancer drugs. Continuous decrease of cell density indicated the slow release of cancer drugs from the NFs. Both PCL+Paclitaxel and PCL+5FU treated conditions caused breast cancer cell death between 40% to 50%. PMID:28845137

Encapsulation of Anticancer Drugs (5-Fluorouracil and Paclitaxel) into Polycaprolactone (PCL) Nanofibers and In Vitro Testing for Sustained and Targeted Therapy.

PubMed

Iqbal, Sakib; Rashid, Mohammad H; Arbab, Ali S; Khan, Mujibur

2017-04-01

We report a continuous nanoscale encapsulation of cancer drugs 5-Fluorouracil (FU) and Paclitaxel into biocompatible polycaprolactone (PCL) nanofibers (NFs) using core-sheath electrospinning process. A high potential electric field of 19-23.2 kV was used to draw a compound solution jet from a specialized coaxial spinneret. Using of DMF in both core and Sheath resulted in NFs within 50-160 nm along with large beaded structures. Addition of Trichloromethane (TCM) or Trifluoroethanol (TFE) in sheath turned NFs in more uniform and thin fiber structure. The diameter range for paclitaxel encapsulated fibers was 22-90 nm with encapsulation efficiency of 77.5% and the amount of drug was only 4 to 5% of sheath polymer. Addition of PVA within core resulted drug nanocrystal formation outside of sheath and poor encapsulation efficiency (52%) with rapid initial release (52-53%) in first 3 days. Drug release test of NFs in different pH exhibited increase of release rate with the decrease of media pH. In-vitro cell viability test with FU encapsulated NFs in human prostatic cancer PC3 cells exhibited 38% alive cells at 5 μM concentration while in pristine FU 43% cells were alive. Paclitaxel encapsulated NFs with breast cancer cells also exhibited increased efficacy in comparison to pristine anticancer drugs. Continuous decrease of cell density indicated the slow release of cancer drugs from the NFs. Both PCL+Paclitaxel and PCL+5FU treated conditions caused breast cancer cell death between 40% to 50%.

Chloe's Law: A Powerful Legislative Movement Challenging a Core Ethical Norm of Genetic Testing.

PubMed

Caplan, Arthur L

2015-08-01

Since the early 1970s, the ethical norm governing counselors involved in testing and screening for genetic conditions related to reproduction has been strict neutrality. Counseling about reproductive genetics was to be patient centered but nondirective. Many advocates for people with Down syndrome believe that high abortion rates following a diagnosis of this condition show an unfounded bias against those with Down syndrome. These advocates have succeeded in enacting federal and state legislation that requires women who receive a prenatal diagnosis of Down syndrome to receive positive information about the condition, thereby ending the nominal goal of value-neutral counseling and setting the stage for further normative shifts in clinical reproductive genetics as counseling expands because of cell-free testing.

Pretest and posttest calculations of Semiscale Test S-07-10D with the TRAC computer program. [PWR

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

Duerre, K.H.; Cort, G.E.; Knight, T.D.

The Transient Reactor Analysis Code (TRAC) developed at the Los Alamos National Laboratory was used to predict the behavior of the small-break experiment designated Semiscale S-07-10D. This test simulates a 10 per cent communicative cold-leg break with delayed Emergency Core Coolant injection and blowdown of the broken-loop steam generator secondary. Both pretest calculations that incorporated measured initial conditions and posttest calculations that incorporated measured initial conditions and measured transient boundary conditions were completed. The posttest calculated parameters were generally between those obtained from pretest calculations and those from the test data. The results are strongly dependent on depressurization rate and,more » hence, on break flow.« less

Value of cytopathologist-performed ultrasound-guided fine-needle aspiration as a screening test for ultrasound-guided core-needle biopsy in nonpalpable breast masses.

PubMed

Lieu, David

2009-04-01

Fine-needle aspiration (FNA) of breast masses in the United States has been on the decline for the last decade and has been largely replaced by ultrasound-guided core-needle biopsy (UG-CNB). Some studies show core-needle biopsy (CNB) is superior to FNA in terms of absolute sensitivity, specificity, and inadequate rate. However, the importance of a skilled aspirator, experienced cytopathologist, and immediate cytological evaluation (ICE) in FNA is often not considered. CNB is more expensive, invasive, risky, and painful than FNA. This prospective study examines the value of cytopathologist-performed ultrasound-guided FNA (UG-FNA) with ICE as a screening test for cytopathologist-performed UG-CNB on nonpalpable or difficult-to-palpate solid breast masses visible on ultrasound. One hundred twenty consecutive nonpalpable or difficult-to-palpate presumably solid breast masses in 109 female patients from January2, 2008 to June 30, 2008 underwent cytopathologist-performed UG-FNA with ICE. Twenty cases were converted to cytopathologist-performed UG-CNB because ICE was inadequate, hypocellular, atypical, suspicious, or malignant. Patients with clearly benign cytology did not undergo UG-CNB. UG-FNA with ICE reduced the percentage of patients undergoing UG-CNB by 87%. A new role for cytopathologist-performed UG-FNA of nonpalpable breast masses has been identified.

Discordance between location of positive cores in biopsy and location of positive surgical margin following radical prostatectomy.

PubMed

Kim, Ji Won; Park, Hyoung Keun; Kim, Hyeong Gon; Ham, Dong Yeub; Paick, Sung Hyun; Lho, Yong Soo; Choi, Woo Suk

2015-10-01

We compared location of positive cores in biopsy and location of positive surgical margin (PSM) following radical prostatectomy. This retrospective analysis included patients who were diagnosed as prostate cancer by standard 12-core transrectal ultrasonography guided prostate biopsy, and who have PSM after radical prostatectomy. After exclusion of number of biopsy cores <12, and lack of biopsy location data, 46 patients with PSM were identified. Locations of PSM in pathologic specimen were reported as 6 difference sites (apex, base and lateral in both sides). Discordance of biopsy result and PSM was defined when no positive cores in biopsy was identified at the location of PSM. Most common location of PSM were right apex (n=21) and left apex (n=15). Multiple PSM was reported in 21 specimens (45.7%). In 32 specimens (69.6%) with PSM, one or more concordant positive biopsy cores were identified, but 14 specimens (28%) had no concordant biopsy cores at PSM location. When discordant rate was separated by locations of PSM, right apex PSM had highest rate of discordant (38%). The discordant group had significantly lower prostate volume and lower number of positive cores in biopsy than concordant group. This study showed that one fourth of PSM occurred at location where tumor was not detected at biopsy and that apex PSM had highest rate of discordant. Careful dissection to avoid PSM should be performed in every location, including where tumor was not identified in biopsy.

Effects of voluntary wheel running on heart rate, body temperature, and locomotor activity in response to acute and repeated stressor exposures in rats.

PubMed

Masini, Cher V; Nyhuis, Tara J; Sasse, Sarah K; Day, Heidi E W; Campeau, Serge

2011-05-01

Stress often negatively impacts physical and mental health but it has been suggested that voluntary physical activity may benefit health by reducing some of the effects of stress. The present experiments tested whether voluntary exercise can reduce heart rate, core body temperature and locomotor activity responses to acute (novelty or loud noise) or repeated stress (loud noise). After 6 weeks of running-wheel access, rats exposed to a novel environment had reduced heart rate, core body temperature, and locomotor activity responses compared to rats housed under sedentary conditions. In contrast, none of these measures were different between exercised and sedentary rats following acute 30-min noise exposures, at either 85 or 98 dB. Following 10 weeks of running-wheel access, both groups displayed significant habituation of all these responses to 10 consecutive daily 30-min presentations of 98 dB noise stress. However, the extent of habituation of all three responses was significantly enhanced in exercised compared to sedentary animals on the last exposure to noise. These results suggest that in physically active animals, under some conditions, acute responses to stress exposure may be reduced, and response habituation to repeated stress may be enhanced, which ultimately may reduce the negative and cumulative impact of stress.

Effects of voluntary wheel running on heart rate, body temperature, and locomotor activity in response to acute and repeated stressor exposures in rats

PubMed Central

MASINI, CHER V.; NYHUIS, TARA J.; SASSE, SARAH K.; DAY, HEIDI E. W.; CAMPEAU, SERGE

2015-01-01

Stress often negatively impacts physical and mental health but it has been suggested that voluntary physical activity may benefit health by reducing some of the effects of stress. The present experiments tested whether voluntary exercise can reduce heart rate, core body temperature and locomotor activity responses to acute (novelty or loud noise) or repeated stress (loud noise). After 6 weeks of running-wheel access, rats exposed to a novel environment had reduced heart rate, core body temperature, and locomotor activity responses compared to rats housed under sedentary conditions. In contrast, none of these measures were different between exercised and sedentary rats following acute 30-min noise exposures, at either 85 or 98 dB. Following 10 weeks of running-wheel access, both groups displayed significant habituation of all these responses to 10 consecutive daily 30-min presentations of 98 dB noise stress. However, the extent of habituation of all three responses was significantly enhanced in exercised compared to sedentary animals on the last exposure to noise. These results suggest that in physically active animals, under some conditions, acute responses to stress exposure may be reduced, and response habituation to repeated stress may be enhanced, which ultimately may reduce the negative and cumulative impact of stress. PMID:21438772

Application of a Virtual Reactivity Feedback Control Loop in Non-Nuclear Testing of a Fast Spectrum Reactor

NASA Technical Reports Server (NTRS)

Bragg-Sitton, Shannon M.; Forsbacka, Matthew

2004-01-01

For a compact, fast-spectrum reactor, reactivity feedback is dominated by core deformation at elevated temperature. Given the use of accurate deformation measurement techniques, it is possible to simulate nuclear feedback in non-nuclear electrically heated reactor tests. Implementation of simulated reactivity feedback in response to measured deflection is being tested at the NASA Marshall Space Flight Center Early Flight Fission Test Facility (EFF-TF). During tests of the SAFE-100 reactor prototype, core deflection was monitored using a high resolution camera. "virtual" reactivity feedback was accomplished by applying the results of Monte Carlo calculations (MCNPX) to core deflection measurements; the computational analysis was used to establish the reactivity worth of van'ous core deformations. The power delivered to the SAFE-100 prototype was then dusted accordingly via kinetics calculations, The work presented in this paper will demonstrate virtual reactivity feedback as core power was increased from 1 kilowatt(sub t), to 10 kilowatts(sub t), held approximately constant at 10 kilowatts (sub t), and then allowed to decrease based on the negative thermal reactivity coefficient.

Testing of an Integrated Reactor Core Simulator and Power Conversion System with Simulated Reactivity Feedback

NASA Technical Reports Server (NTRS)

Bragg-Sitton, Shannon M.; Hervol, David S.; Godfroy, Thomas J.

2009-01-01

A Direct Drive Gas-Cooled (DDG) reactor core simulator has been coupled to a Brayton Power Conversion Unit (BPCU) for integrated system testing at NASA Glenn Research Center (GRC) in Cleveland, OH. This is a closed-cycle system that incorporates an electrically heated reactor core module, turbo alternator, recuperator, and gas cooler. Nuclear fuel elements in the gas-cooled reactor design are replaced with electric resistance heaters to simulate the heat from nuclear fuel in the corresponding fast spectrum nuclear reactor. The thermodynamic transient behavior of the integrated system was the focus of this test series. In order to better mimic the integrated response of the nuclear-fueled system, a simulated reactivity feedback control loop was implemented. Core power was controlled by a point kinetics model in which the reactivity feedback was based on core temperature measurements; the neutron generation time and the temperature feedback coefficient are provided as model inputs. These dynamic system response tests demonstrate the overall capability of a non-nuclear test facility in assessing system integration issues and characterizing integrated system response times and response characteristics.

Testing of an Integrated Reactor Core Simulator and Power Conversion System with Simulated Reactivity Feedback

NASA Technical Reports Server (NTRS)

Bragg-Sitton, Shannon M.; Hervol, David S.; Godfroy, Thomas J.

2010-01-01

A Direct Drive Gas-Cooled (DDG) reactor core simulator has been coupled to a Brayton Power Conversion Unit (BPCU) for integrated system testing at NASA Glenn Research Center (GRC) in Cleveland, Ohio. This is a closed-cycle system that incorporates an electrically heated reactor core module, turboalternator, recuperator, and gas cooler. Nuclear fuel elements in the gas-cooled reactor design are replaced with electric resistance heaters to simulate the heat from nuclear fuel in the corresponding fast spectrum nuclear reactor. The thermodynamic transient behavior of the integrated system was the focus of this test series. In order to better mimic the integrated response of the nuclear-fueled system, a simulated reactivity feedback control loop was implemented. Core power was controlled by a point kinetics model in which the reactivity feedback was based on core temperature measurements; the neutron generation time and the temperature feedback coefficient are provided as model inputs. These dynamic system response tests demonstrate the overall capability of a non-nuclear test facility in assessing system integration issues and characterizing integrated system response times and response characteristics.

Evaluation of the Transient Liquid Phase (TLP) Bonding Process for Ti3Al-Based Honeycomb Core Sandwich Structure

NASA Technical Reports Server (NTRS)

Bird, R. Keith; Hoffman, Eric K.

1998-01-01

The suitability of using transient liquid phase (TLP) bonding to fabricate honeycomb core sandwich panels with Ti-14Al-21Nb (wt%) titanium aluminide (T3Al) face sheets for high-temperature hypersonic vehicle applications was evaluated. Three titanium alloy honeycomb cores and one Ti3Al alloy honeycomb core were investigated. Edgewise compression (EWC) and flatwise tension (FWT) tests on honeycomb core sandwich specimens and tensile tests of the face sheet material were conducted at temperatures ranging from room temperature to 1500 F. EWC tests indicated that the honeycomb cores and diffusion bonded joints were able to stabilize the face sheets up to and beyond the face sheet compressive yield strength for all temperatures investigated. The specimens with the T3Al honeycomb core produced the highest FWT strengths at temperatures above 1000 F. Tensile tests indicated that TLP processing conditions resulted in decreases in ductility of the Ti-14Al-21Nb face sheets. Microstructural examination showed that the side of the face sheets to which the filler metals had been applied was transformed from equiaxed alpha2 grains to coarse plates of alpha2 with intergranular Beta. Fractographic examination of the tensile specimens showed that this transformed region was dominated by brittle fracture.

Differential catalytic promiscuity of the alkaline phosphatase superfamily bimetallo core reveals mechanistic features underlying enzyme evolution

DOE PAGES

Sunden, Fanny; AlSadhan, Ishraq; Lyubimov, Artem; ...

2017-10-25

Members of enzyme superfamilies specialize in different reactions but often exhibit catalytic promiscuity for one another's reactions, consistent with catalytic promiscuity as an important driver in the evolution of new enzymes. Wanting to understand how catalytic promiscuity and other factors may influence evolution across a superfamily, we turned to the well-studied alkaline phosphatase (AP) superfamily, comparing three of its members, two evolutionarily distinct phosphatases and a phosphodiesterase. Here, we mutated distinguishing active-site residues to generate enzymes that had a common Zn 2+ bimetallo core but little sequence similarity and different auxiliary domains. We then tested the catalytic capabilities of thesemore » pruned enzymes with a series of substrates. A substantial rate enhancement of ~1011-fold for both phosphate mono- and diester hydrolysis by each enzyme indicated that the Zn 2+ bimetallo core is an effective mono/di-esterase generalist and that the bimetallo cores were not evolutionarily tuned to prefer their cognate reactions. In contrast, our pruned enzymes were ineffective sulfatases, and this limited promiscuity may have provided a driving force for founding the distinct one-metal-ion branch that contains all known AP superfamily sulfatases. Finally, our pruned enzymes exhibited 10 7–10 8-fold phosphotriesterase rate enhancements, despite absence of such enzymes within the AP superfamily. We speculate that the superfamily active-site architecture involved in nucleophile positioning prevents accommodation of the additional triester substituent. Overall, we suggest that catalytic promiscuity, and the ease or difficulty of remodeling and building onto existing protein scaffolds, have greatly influenced the course of enzyme evolution. Uncovering principles and properties of enzyme function, promiscuity, and repurposing provides lessons for engineering new enzymes.« less

Inferring the lithology of borehole rocks by applying neural network classifiers to downhole logs: an example from the Ocean Drilling Program

NASA Astrophysics Data System (ADS)

Benaouda, D.; Wadge, G.; Whitmarsh, R. B.; Rothwell, R. G.; MacLeod, C.

1999-02-01

In boreholes with partial or no core recovery, interpretations of lithology in the remainder of the hole are routinely attempted using data from downhole geophysical sensors. We present a practical neural net-based technique that greatly enhances lithological interpretation in holes with partial core recovery by using downhole data to train classifiers to give a global classification scheme for those parts of the borehole for which no core was retrieved. We describe the system and its underlying methods of data exploration, selection and classification, and present a typical example of the system in use. Although the technique is equally applicable to oil industry boreholes, we apply it here to an Ocean Drilling Program (ODP) borehole (Hole 792E, Izu-Bonin forearc, a mixture of volcaniclastic sandstones, conglomerates and claystones). The quantitative benefits of quality-control measures and different subsampling strategies are shown. Direct comparisons between a number of discriminant analysis methods and the use of neural networks with back-propagation of error are presented. The neural networks perform better than the discriminant analysis techniques both in terms of performance rates with test data sets (2-3 per cent better) and in qualitative correlation with non-depth-matched core. We illustrate with the Hole 792E data how vital it is to have a system that permits the number and membership of training classes to be changed as analysis proceeds. The initial classification for Hole 792E evolved from a five-class to a three-class and then to a four-class scheme with resultant classification performance rates for the back-propagation neural network method of 83, 84 and 93 per cent respectively.

Exploration drilling and reservoir model of the Platanares geothermal system, Honduras, Central America

USGS Publications Warehouse

Goff, F.; Goff, S.J.; Kelkar, S.; Shevenell, L.; Truesdell, A.H.; Musgrave, J.; Rufenacht, H.; Flores, W.

1991-01-01

Results of drilling, logging, and testing of three exploration core holes, combined with results of geologic and hydrogeochemical investigations, have been used to present a reservoir model of the Platanares geothermal system, Honduras. Geothermal fluids circulate at depths ??? 1.5 km in a region of active tectonism devoid of Quaternary volcanism. Large, artesian water entries of 160 to 165??C geothermal fluid in two core holes at 625 to 644 m and 460 to 635 m depth have maximum flow rates of roughly 355 and 560 l/min, respectively, which are equivalent to power outputs of about 3.1 and 5.1 MW(thermal). Dilute, alkali-chloride reservoir fluids (TDS ??? 1200 mg/kg) are produced from fractured Miocene andesite and Cretaceous to Eocene redbeds that are hydrothermally altered. Fracture permeabillity in producing horizons is locally greater than 1500 and bulk porosity is ??? 6%. A simple, fracture-dominated, volume-impedance model assuming turbulent flow indicates that the calculated reservoir storage capacity of each flowing hole is approximately 9.7 ?? 106 l/(kg cm-2), Tritium data indicate a mean residence time of 450 yr for water in the reservoir. Multiplying the natural fluid discharge rate by the mean residence time gives an estimated water volume of the Platanares system of ??? 0.78 km3. Downward continuation of a 139??C/km "conductive" gradient at a depth of 400 m in a third core hole implies that the depth to a 225??C source reservoir (predicted from chemical geothermometers) is at least 1.5 km. Uranium-thorium disequilibrium ages on calcite veins at the surface and in the core holes indicate that the present Platanares hydrothermal system has been active for the last 0.25 m.y. ?? 1991.

Differential catalytic promiscuity of the alkaline phosphatase superfamily bimetallo core reveals mechanistic features underlying enzyme evolution

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

Sunden, Fanny; AlSadhan, Ishraq; Lyubimov, Artem

Members of enzyme superfamilies specialize in different reactions but often exhibit catalytic promiscuity for one another's reactions, consistent with catalytic promiscuity as an important driver in the evolution of new enzymes. Wanting to understand how catalytic promiscuity and other factors may influence evolution across a superfamily, we turned to the well-studied alkaline phosphatase (AP) superfamily, comparing three of its members, two evolutionarily distinct phosphatases and a phosphodiesterase. Here, we mutated distinguishing active-site residues to generate enzymes that had a common Zn 2+ bimetallo core but little sequence similarity and different auxiliary domains. We then tested the catalytic capabilities of thesemore » pruned enzymes with a series of substrates. A substantial rate enhancement of ~1011-fold for both phosphate mono- and diester hydrolysis by each enzyme indicated that the Zn 2+ bimetallo core is an effective mono/di-esterase generalist and that the bimetallo cores were not evolutionarily tuned to prefer their cognate reactions. In contrast, our pruned enzymes were ineffective sulfatases, and this limited promiscuity may have provided a driving force for founding the distinct one-metal-ion branch that contains all known AP superfamily sulfatases. Finally, our pruned enzymes exhibited 10 7–10 8-fold phosphotriesterase rate enhancements, despite absence of such enzymes within the AP superfamily. We speculate that the superfamily active-site architecture involved in nucleophile positioning prevents accommodation of the additional triester substituent. Overall, we suggest that catalytic promiscuity, and the ease or difficulty of remodeling and building onto existing protein scaffolds, have greatly influenced the course of enzyme evolution. Uncovering principles and properties of enzyme function, promiscuity, and repurposing provides lessons for engineering new enzymes.« less

Use of the [(14)C]leucine incorporation technique to measure bacterial production in river sediments and the epiphyton.

PubMed

Fischer, H; Pusch, M

1999-10-01

Bacterial production is a key parameter for the understanding of carbon cycling in aquatic ecosystems, yet it remains difficult to measure in many aquatic habitats. We therefore tested the applicability of the [(14)C]leucine incorporation technique for the measurement of bulk bacterial production in various habitats of a lowland river ecosystem. To evaluate the method, we determined (i) extraction efficiencies of bacterial protein from the sediments, (ii) substrate saturation of leucine in sediments, the biofilms on aquatic plants (epiphyton), and the pelagic zone, (iii) bacterial activities at different leucine concentrations, (iv) specificity of leucine uptake by bacteria, and (v) the effect of the incubation technique (perfused-core incubation versus slurry incubation) on leucine incorporation into protein. Bacterial protein was best extracted from sediments and precipitated by hot trichloroacetic acid treatment following ultrasonication. For epiphyton, an alkaline-extraction procedure was most efficient. Leucine incorporation saturation occurred at 1 microM in epiphyton and 100 nM in the pelagic zone. Saturation curves in sediments were difficult to model but showed the first level of leucine saturation at 50 microM. Increased uptake at higher leucine concentrations could be partly attributed to eukaryotes. Addition of micromolar concentrations of leucine did not enhance bacterial electron transport activity or DNA replication activity. Similar rates of leucine incorporation into protein calculated for whole sediment cores were observed after slurry and perfused-core incubations, but the rates exhibited strong vertical gradients after the core incubation. We conclude that the leucine incorporation method can measure bacterial production in a wide range of aquatic habitats, including fluvial sediments, if substrate saturation and isotope dilution are determined.

Use of the [14C]Leucine Incorporation Technique To Measure Bacterial Production in River Sediments and the Epiphyton

PubMed Central

Fischer, Helmut; Pusch, Martin

1999-01-01

Bacterial production is a key parameter for the understanding of carbon cycling in aquatic ecosystems, yet it remains difficult to measure in many aquatic habitats. We therefore tested the applicability of the [14C]leucine incorporation technique for the measurement of bulk bacterial production in various habitats of a lowland river ecosystem. To evaluate the method, we determined (i) extraction efficiencies of bacterial protein from the sediments, (ii) substrate saturation of leucine in sediments, the biofilms on aquatic plants (epiphyton), and the pelagic zone, (iii) bacterial activities at different leucine concentrations, (iv) specificity of leucine uptake by bacteria, and (v) the effect of the incubation technique (perfused-core incubation versus slurry incubation) on leucine incorporation into protein. Bacterial protein was best extracted from sediments and precipitated by hot trichloroacetic acid treatment following ultrasonication. For epiphyton, an alkaline-extraction procedure was most efficient. Leucine incorporation saturation occurred at 1 μM in epiphyton and 100 nM in the pelagic zone. Saturation curves in sediments were difficult to model but showed the first level of leucine saturation at 50 μM. Increased uptake at higher leucine concentrations could be partly attributed to eukaryotes. Addition of micromolar concentrations of leucine did not enhance bacterial electron transport activity or DNA replication activity. Similar rates of leucine incorporation into protein calculated for whole sediment cores were observed after slurry and perfused-core incubations, but the rates exhibited strong vertical gradients after the core incubation. We conclude that the leucine incorporation method can measure bacterial production in a wide range of aquatic habitats, including fluvial sediments, if substrate saturation and isotope dilution are determined. PMID:10508068

Physiological Responses and Physical Performance during Football in the Heat

PubMed Central

Mohr, Magni; Nybo, Lars; Grantham, Justin; Racinais, Sebastien

2012-01-01

Purpose To examine the impact of hot ambient conditions on physical performance and physiological responses during football match-play. Methods Two experimental games were completed in temperate (∼21°C; CON) and hot ambient conditions (∼43°C; HOT). Physical performance was assessed by match analysis in 17 male elite players during the games and a repeated sprint test was conducted after the two game trials. Core and muscle temperature were measured and blood samples were obtained, before and after the games. Results Muscle and core temperatures were ∼1°C higher (P<0.05) in HOT (40.3±0.1 and 39.5±0.1°C, respectively) compared to CON (39.2±0.1 and 38.3±0.1°C). Average heart rate, plasma lactate concentration, body weight loss as well as post-game sprint performance were similar between the two conditions. Total game distance declined (P<0.05) by 7% and high intensity running (>14 km⋅h−1) by 26% in HOT compared to CON), but peak sprint speed was 4% higher (P<0.05) in HOT than in CON, while there were no differences in the quantity or length of sprints (>24 km⋅h−1) between CON and HOT. In HOT, success rates for passes and crosses were 8 and 9% higher (P<0.05), respectively, compared to CON. Delta increase in core temperature and absolute core temperature in HOT were correlated to total game distance in the heat (r = 0.85 and r = 0.53, respectively; P<0.05), whereas, total and high intensity distance deficit between CON and HOT were not correlated to absolute or delta changes in muscle or core temperature. Conclusion Total game distance and especially high intensity running were lower during a football game in the heat, but these changes were not directly related to the absolute or relative changes in core or muscle temperature. However, peak sprinting speed and execution of successful passes and crosses were improved in the HOT condition. PMID:22723963

Exploring coral reef responses to millennial-scale climatic forcings: insights from the 1-D numerical tool pyReef-Core v1.0

NASA Astrophysics Data System (ADS)

Salles, Tristan; Pall, Jodie; Webster, Jody M.; Dechnik, Belinda

2018-06-01

Assemblages of corals characterise specific reef biozones and the environmental conditions that change spatially across a reef and with depth. Drill cores through fossil reefs record the time and depth distribution of assemblages, which captures a partial history of the vertical growth response of reefs to changing palaeoenvironmental conditions. The effects of environmental factors on reef growth are well understood on ecological timescales but are poorly constrained at centennial to geological timescales. pyReef-Core is a stratigraphic forward model designed to solve the problem of unobservable environmental processes controlling vertical reef development by simulating the physical, biological and sedimentological processes that determine vertical assemblage changes in drill cores. It models the stratigraphic development of coral reefs at centennial to millennial timescales under environmental forcing conditions including accommodation (relative sea-level upward growth), oceanic variability (flow speed, nutrients, pH and temperature), sediment input and tectonics. It also simulates competitive coral assemblage interactions using the generalised Lotka-Volterra system of equations (GLVEs) and can be used to infer the influence of environmental conditions on the zonation and vertical accretion and stratigraphic succession of coral assemblages over decadal timescales and greater. The tool can quantitatively test carbonate platform development under the influence of ecological and environmental processes and efficiently interpret vertical growth and karstification patterns observed in drill cores. We provide two realistic case studies illustrating the basic capabilities of the model and use it to reconstruct (1) the Holocene history (from 8500 years to present) of coral community responses to environmental changes and (2) the evolution of an idealised coral reef core since the last interglacial (from 140 000 years to present) under the influence of sea-level change, subsidence and karstification. We find that the model reproduces the details of the formation of existing coral reef stratigraphic sequences both in terms of assemblages succession, accretion rates and depositional thicknesses. It can be applied to estimate the impact of changing environmental conditions on growth rates and patterns under many different settings and initial conditions.

Ice Cores Dating With a New Inverse Method Taking Account of the Flow Modeling Errors

NASA Astrophysics Data System (ADS)

Lemieux-Dudon, B.; Parrenin, F.; Blayo, E.

2007-12-01

Deep ice cores extracted from Antarctica or Greenland recorded a wide range of past climatic events. In order to contribute to the Quaternary climate system understanding, the calculation of an accurate depth-age relationship is a crucial point. Up to now ice chronologies for deep ice cores estimated with inverse approaches are based on quite simplified ice-flow models that fail to reproduce flow irregularities and consequently to respect all available set of age markers. We describe in this paper, a new inverse method that takes into account the model uncertainty in order to circumvent the restrictions linked to the use of simplified flow models. This method uses first guesses on two flow physical entities, the ice thinning function and the accumulation rate and then identifies correction functions on both flow entities. We highlight two major benefits brought by this new method: first of all the ability to respect large set of observations and as a consequence, the feasibility to estimate a synchronized common ice chronology for several cores at the same time. This inverse approach relies on a bayesian framework. To respect the positive constraint on the searched correction functions, we assume lognormal probability distribution on one hand for the background errors, but also for one particular set of the observation errors. We test this new inversion method on three cores simultaneously (the two EPICA cores : DC and DML and the Vostok core) and we assimilate more than 150 observations (e.g.: age markers, stratigraphic links,...). We analyze the sensitivity of the solution with respect to the background information, especially the prior error covariance matrix. The confidence intervals based on the posterior covariance matrix calculation, are estimated on the correction functions and for the first time on the overall output chronologies.

Variations in soil detachment rates after wildfire as a function of soil depth, flow properties, and root properties

USGS Publications Warehouse

Moody, John A.; Nyman, Peter

2013-01-01

Wildfire affects hillslope erosion through increased surface runoff and increased sediment availability, both of which contribute to large post-fire erosion events. Relations between soil detachment rate, soil depth, flow and root properties, and fire impacts are poorly understood and not represented explicitly in commonly used post-fire erosion models. Detachment rates were measured on intact soil cores using a modified tilting flume. The cores were mounted flush with the flume-bed and a measurement was made on the surface of the core. The core was extruded upward, cut off, and another measurement was repeated at a different depth below the original surface of the core. Intact cores were collected from one site burned by the 2010 Fourmile Canyon (FMC) fire in Colorado and from one site burned by the 2010 Pozo fire in California. Each site contained contrasting vegetation and soil types. Additional soil samples were collected alongside the intact cores and were analyzed in the laboratory for soil properties (organic matter, bulk density, particle-size distribution) and for root properties (root density and root-length density). Particle-size distribution and root properties were different between sites, but sites were similar in terms of bulk density and organic matter. Soil detachment rates had similar relations with non-uniform shear stress and non-uniform unit stream power. Detachment rates within single sampling units displayed a relatively weak and inconsistent relation to flow variables. When averaged across all clusters, the detachment rate displayed a linear relation to shear stress, but variability in soil properties meant that the shear stress accounted for only a small proportion of the overall variability in detachment rates (R2 = 0.23; R2 is the coefficient of determination). Detachment rate was related to root-length density in some clusters (R2 values up to 0.91) and unrelated in others (R2 values 2 value improved and the range of exponents became narrower by applying a multivariate regression model where boundary shear stress and root-length density were included as explanatory variables. This suggests that an erodibility parameter which incorporates the effects of both flow and root properties on detachment could improve the representation of sediment availability after wildfire.

An experimental study of relative permeability hysteresis, capillary trapping characteristics, and capillary pressure of CO2/brine systems at reservoir conditions

NASA Astrophysics Data System (ADS)

Akbarabadi, Morteza

We present the results of an extensive experimental study on the effects of hysteresis on permanent capillary trapping and relative permeability of CO2/brine and supercritical (sc)CO2+SO2/brine systems. We performed numerous unsteady- and steady-state drainage and imbibition full-recirculation flow experiments in three different sandstone rock samples, i.e., low and high-permeability Berea, Nugget sandstones, and Madison limestone carbonate rock sample. A state-of-the-art reservoir conditions core-flooding system was used to perform the tests. The core-flooding apparatus included a medical CT scanner to measure in-situ saturations. The scanner was rotated to the horizontal orientation allowing flow tests through vertically-placed core samples with about 3.8 cm diameter and 15 cm length. Both scCO2 /brine and gaseous CO2 (gCO2)/brine fluid systems were studied. The gaseous and supercritical CO2/brine experiments were carried out at 3.46 and 11 MPa back pressures and 20 and 55°C temperatures, respectively. Under the above-mentioned conditions, the gCO2 and scCO2 have 0.081 and 0.393 gr/cm3 densities, respectively. During unsteady-state tests, the samples were first saturated with brine and then flooded with CO2 (drainage) at different maximum flow rates. The drainage process was then followed by a low flow rate (0.375 cm 3/min) imbibition until residual CO2 saturation was achieved. Wide flow rate ranges of 0.25 to 20 cm3/min for scCO2 and 0.125 to 120 cm3min for gCO2 were used to investigate the variation of initial brine saturation (Swi) with maximum CO2 flow rate and variation of trapped CO2 saturation (SCO2r) with Swi. For a given Swi, the trapped scCO2 saturation was less than that of gCO2 in the same sample. This was attributed to brine being less wetting in the presence of scCO2 than in the presence of gCO 2. During the steady-state experiments, after providing of fully-brine saturated core, scCO2 was injected along with brine to find the drainage curve and as a consequence the Swi, then it was followed by the imbibition process to measure SCO2r. We performed different cycles of relative permeability experiments to investigate the effect of hysteresis. The Swi and SCO2r varied from 0.525 to 0.90 and 0.34 to 0.081, respectively. Maximum CO2 and brine relative permeabilities at the end of drainage and imbibition and also variation of brine relative permeability due to post-imbibition CO2 dissolution during unsteady-state experiment were also studied. We co-injected SO2 with CO2 and brine into the Madison limestone core sample. The sample was acquired from the Rock Springs Uplift in southwest Wyoming. The temperature and pressure of the experiments were 60°C and 19.16 MPa, respectively. Each drainage-imbibition cycle was followed by a dissolution process to establish Sw=1. The results showed that about 76% of the initial CO2 was trapped by capillary trapping mechanism at the end of imbibition test. We also investigated the scCO2+SO2/brine capillary pressure versus saturation relationship through performing primary drainage, imbibition, and secondary drainage experiments. The results indicated that the wettability of the core sample might have been altered owing to being in contact with the scCO 2+SO2/brine system. During primary drainage CO2 displaced 52.5% of brine, i.e., Swi = 0.475. The subsequent imbibition led to 0.329 CO2 saturation. For all series of experiments, the ratio of SCO2r to initial CO2 saturation (1- S wi) was found to be much higher for low initial CO2 saturations. This means that greater fractions of injected CO2 can be permanently trapped at higher initial brine saturations. The results illustrated that very promising fractions (about 49 to 83 %) of the initial CO2 saturation can be trapped permanently. (Abstract shortened by UMI.).

Does oxygen exposure time control the extent of organic matter decomposition in peatlands?

NASA Astrophysics Data System (ADS)

Philben, Michael; Kaiser, Karl; Benner, Ronald

2014-05-01

The extent of peat decomposition was investigated in four cores collected along a latitudinal gradient from 56°N to 66°N in the West Siberian Lowland. The acid:aldehyde ratios of lignin phenols were significantly higher in the two northern cores compared with the two southern cores, indicating peats at the northern sites were more highly decomposed. Yields of hydroxyproline, an amino acid found in plant structural glycoproteins, were also significantly higher in northern cores compared with southern cores. Hydroxyproline-rich glycoproteins are not synthesized by microbes and are generally less reactive than bulk plant carbon, so elevated yields indicated that northern cores were more extensively decomposed than the southern cores. The southern cores experienced warmer temperatures, but were less decomposed, indicating that temperature was not the primary control of peat decomposition. The plant community oscillated between Sphagnum and vascular plant dominance in the southern cores, but vegetation type did not appear to affect the extent of decomposition. Oxygen exposure time appeared to be the strongest control of the extent of peat decomposition. The northern cores had lower accumulation rates and drier conditions, so these peats were exposed to oxic conditions for a longer time before burial in the catotelm, where anoxic conditions prevail and rates of decomposition are generally lower by an order of magnitude.

Influence of core thickness and artificial aging on the biaxial flexural strength of different all-ceramic materials: An in-vitro study.

PubMed

Dikicier, Sibel; Ayyildiz, Simel; Ozen, Julide; Sipahi, Cumhur

2017-05-31

The purpose of this study was to investigate the flexural strength of all-ceramics with varying core thicknesses submitted to aging. In-Ceram Alumina (IC), IPS e.max Press (EM) and Katana (K) (n=40), were selected. Each group contained two core groups based on the core thickness as follows: IC/0.5, IC/0.8, EM/0.5, EM/0.8, K/0.5 and K/0.8 mm in thickness (n=20 each). Ten specimens from each group were subjected to aging and all specimens were tested for strength in a testing machine either with or without being subjected aging. The mean strength of the K were higher (873.05 MPa) than that of the IC (548.28 MPa) and EM (374.32 MPa) regardless of core thickness. Strength values increased with increasing core thickness for all IC, EM and K regardless of aging. Results of this study concluded that strength was not significantly affected by aging. Different core thicknesses affected strength of the all-ceramic materials tested (p<0.05).

30 CFR 784.22 - Geologic information.

Code of Federal Regulations, 2014 CFR

2014-07-01

... be collected and analyzed from test borings; drill cores; or fresh, unweathered, uncontaminated... not be removed, samples shall be collected and analyzed from test borings or drill cores to provide...

30 CFR 784.22 - Geologic information.

Code of Federal Regulations, 2013 CFR

2013-07-01

... be collected and analyzed from test borings; drill cores; or fresh, unweathered, uncontaminated... not be removed, samples shall be collected and analyzed from test borings or drill cores to provide...

EBUS-TBNA Provides Highest RNA Yield for Multiple Biomarker Testing from Routinely Obtained Small Biopsies in Non-Small Cell Lung Cancer Patients - A Comparative Study of Three Different Minimal Invasive Sampling Methods

PubMed Central

Schmid-Bindert, Gerald; Wang, Yongsheng; Jiang, Hongbin; Sun, Hui; Henzler, Thomas; Wang, Hao; Pilz, Lothar R.; Ren, Shengxiang; Zhou, Caicun

2013-01-01

Background Multiple biomarker testing is necessary to facilitate individualized treatment of lung cancer patients. More than 80% of lung cancers are diagnosed based on very small tumor samples. Often there is not enough tissue for molecular analysis. We compared three minimal invasive sampling methods with respect to RNA quantity for molecular testing. Methods 106 small biopsies were prospectively collected by three different methods forceps biopsy, endobronchial ultrasound (EBUS) guided transbronchial needle aspiration (TBNA), and CT-guided core biopsy. Samples were split into two halves. One part was formalin fixed and paraffin embedded for standard pathological evaluation. The other part was put in RNAlater for immediate RNA/DNA extraction. If the pathologist confirmed the diagnosis of non-small cell lung cancer(NSCLC), the following molecular markers were tested: EGFR mutation, ERCC1, RRM1 and BRCA1. Results Overall, RNA-extraction was possible in 101 out of 106 patients (95.3%). We found 49% adenocarcinomas, 38% squamouscarcinomas, and 14% non-otherwise-specified(NOS). The highest RNA yield came from endobronchial ultrasound guided needle aspiration, which was significantly higher than bronchoscopy (37.74±41.09 vs. 13.74±15.53 ng respectively, P = 0.005) and numerically higher than CT-core biopsy (37.74±41.09 vs. 28.72±44.27 ng respectively, P = 0.244). EGFR mutation testing was feasible in 100% of evaluable patients and its incidence was 40.8%, 7.9% and 14.3% in adenocarcinomas, squamouscarcinomas and NSCLC NOS subgroup respectively. There was no difference in the feasibility of molecular testing between the three sampling methods with feasibility rates for ERCC1, RRM1 and BRCA1 of 91%, 87% and 81% respectively. Conclusion All three methods can provide sufficient tumor material for multiple biomarkers testing from routinely obtained small biopsies in lung cancer patients. In our study EBUS guided needle aspiration provided the highest amount of tumor RNA compared to bronchoscopy or CT guided core biopsy. Thus EBUS should be considered as an acceptable option for tissue acquisition for molecular testing. PMID:24205040

Mineralization and nitrification patterns at eight northeastern USA forested research sites

USGS Publications Warehouse

Ross, D.S.; Lawrence, G.B.; Fredriksen, G.

2004-01-01

Nitrogen transformation rates in eight northeastern US research sites were measured in soil samples taken in the early season of 2000 and the late season of 2001. Net mineralization and nitrification rates were determined on Oa or A horizon samples by two different sampling methods - intact cores and repeated measurements on composite samples taken from around the cores. Net rates in the composite samples (n=30) showed three different temporal patterns: high net nitrification with minimal NH4+ accumulation, high net nitrification and high NH4+ accumulation, and minimal net nitrification and moderate NH4+ accumulation. The 4-week net rates in intact cores were about half that of the rates from the composite samples but were well related (R2 > 0.70). Composite samples from sites that exhibited high net nitrification were incubated with acetylene and net nitrification was completely stopped, suggesting an autotrophic pathway. Gross mineralization and nitrification (2000 only) rates were estimated using the isotope dilution technique. Gross rates of nitrification and consumption in intact cores were relatively low. Gross rates of mineralization and net rates of nitrification were both related to the soil C/N ratio, with higher rates generally occurring in sites containing Acer saccharum as a dominant or co-dominant species. The comparison of methods suggests that all provide a similar hierarchy of potential rates but that the degree of net nitrification is strongly influenced by the degree of sample disturbance. Differences between sites appear to be related to an interaction of soil (C/N) and vegetation (A. saccharum contribution) characteristics. ?? 2003 Elsevier B.V. All rights reserved.

Permeability and compressibility of resedimented Gulf of Mexico mudrock

NASA Astrophysics Data System (ADS)

Betts, W. S.; Flemings, P. B.; Schneider, J.

2011-12-01

We use a constant-rate-of strain consolidation test on resedimented Gulf of Mexico mudrock to determine the compression index (Cc) to be 0.618 and the expansion index (Ce) to be 0.083. We used crushed, homogenized Pliocene and Pleistocene mudrock extracted from cored wells in the Eugene Island block 330 oil field. This powdered material has a liquid limit (LL) of 87, a plastic limit (PL) of 24, and a plasticity index (PI) of 63. The particle size distribution from hydrometer analyses is approximately 65% clay-sized particles (<2 μm) with the remainder being less than 70 microns in diameter. Resedimented specimens have been used to characterize the geotechnical and geophysical behavior of soils and mudstones independent of the variability of natural samples and without the effects of sampling disturbance. Previous investigations of resedimented offshore Gulf of Mexico sediments (e.g. Mazzei, 2008) have been limited in scope. This is the first test of the homogenized Eugene Island core material. These results will be compared to in situ measurements to determine the controls on consolidation over large stress ranges.

Thermonuclear reactions probed at stellar-core conditions with laser-based inertial-confinement fusion

DOE PAGES

Casey, D. T.; Sayre, D. B.; Brune, C. R.; ...

2017-08-07

Stars are giant thermonuclear plasma furnaces that slowly fuse the lighter elements in the universe into heavier elements, releasing energy, and generating the pressure required to prevent collapse. To understand stars, we must rely on nuclear reaction rate data obtained, up to now, under conditions very different from those of stellar cores. Here we show thermonuclear measurements of the 2H(d, n) 3He and 3H(t,2n) 4He S-factors at a range of densities (1.2–16 g cm –3) and temperatures (2.1–5.4 keV) that allow us to test the conditions of the hydrogen-burning phase of main-sequence stars. The relevant conditions are created using inertial-confinementmore » fusion implosions at the National Ignition Facility. Here, our data agree within uncertainty with previous accelerator-based measurements and establish this approach for future experiments to measure other reactions and to test plasma-nuclear effects present in stellar interiors, such as plasma electron screening, directly in the environments where they occur.« less

Continuous measurement of tympanic temperature with a new infrared method using an optical fiber.

PubMed

Shibasaki, M; Kondo, N; Tominaga, H; Aoki, K; Hasegawa, E; Idota, Y; Moriwaki, T

1998-09-01

The purpose of this study was to investigate the utility of an infrared tympanic thermometry by using an optical fiber for measuring tympanic temperature (Tty). In the head cooling and facial fanning tests during normothermia, right Tty measured by this method (infrared-Tty) and esophageal temperature (Tes) were not affected by decreased temple and forehead skin temperatures, suggesting that the infrared sensor in this system measured the infrared radiation from the tympanic membrane selectively. Eight male subjects took part in passive-heat-stress and progressive-exercise tests. No significant differences among infrared-Tty, the left Tty measured by thermistor (contact-Tty), and Tes were observed at rest or at the end of each experiment, and there was no significant difference in the increase in these core temperatures from rest to the end. Furthermore, there were no significant differences in the core temperature threshold at the onset of sweating and slope (the relationship of sweating rate vs. infrared-Tty and vs. contact-Tty). These results suggest that this method makes it possible to measure Tty accurately, continuously, and more safely.

Investigation of the Profile Control Mechanisms of Dispersed Particle Gel

PubMed Central

Zhao, Guang; Dai, Caili; Zhao, Mingwei

2014-01-01

Dispersed particle gel (DPG) particles of nano- to micron- to mm-size have been prepared successfully and will be used for profile control treatment in mature oilfields. The profile control and enhanced oil recovery mechanisms of DPG particles have been investigated using core flow tests and visual simulation experiments. Core flow test results show that DPG particles can easily be injected into deep formations and can effectively plug the high permeability zones. The high profile improvement rate improves reservoir heterogeneity and diverts fluid into the low permeability zone. Both water and oil permeability were reduced when DPG particles were injected, but the disproportionate permeability reduction effect was significant. Water permeability decreases more than the oil permeability to ensure that oil flows in its own pathways and can easily be driven out. Visual simulation experiments demonstrate that DPG particles can pass directly or by deformation through porous media and enter deep formations. By retention, adsorption, trapping and bridging, DPG particles can effectively reduce the permeability of porous media in high permeability zones and divert fluid into a low permeability zone, thus improving formation profiles and enhancing oil recovery. PMID:24950174

A low-power high-speed ultra-wideband pulse radio transmission system.

PubMed

Wei Tang; Culurciello, E

2009-10-01

We present a low-power high-speed ultra-wideband (UWB) transmitter with a wireless transmission test platform. The system is specifically designed for low-power high-speed wireless implantable biosensors. The integrated transmitter consists of a compact pulse generator and a modulator. The circuit is fabricated in the 0.5-mum silicon-on-sapphire process and occupies 420 mum times 420 mum silicon area. The transmitter is capable of generating pulses with 1-ns width and the pulse rate can be controlled between 90 MHz and 270 MHz. We built a demonstration/testing system for the transmitter. The transmitter achieves a 14-Mb/s data rate. With 50% duty cycle data, the power consumption of the chip is between 10 mW and 21 mW when the transmission distance is from 3.2 to 4 m. The core circuit size is 70 mum times 130 mum.

UNIT OPERATIONS SECTION MONTHLY PROGRESS REPORT, OCTOBER 1961

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

Whatley, M.E.; Haas, P.A.; Horton, R.W.

1962-04-01

Additional runs were made in the 6-in.-dia. separation column. The kinetics of the methane --copper oxide reaction was investigated in deep bed tests. The work on the development of the shear included a satisfactory method of ng, preliminary test of an outer gag faced with rubber, and a metallic inner gsg contoured to the shape of a sheared assembly. The mechanical dejacketing of the SRE Core I fuel, NaK-bonded, stainless steel-clad uranium slugs, was successfully completed. The effective therrnal conductivity of a packed bed of 0.023-in. steel shot was approximately 0.33 Btu/hr- deg Fft at 200 deg F. Flow capacitymore » for the compound extraction scrub column equipped with sieve plates (0.125-in.-dia. was determined. Average waste calcination rates for Purex were higher by a factor of 1.5 to 2.0 than rates for TBP-25. (auth)« less

The effects of 6-week training programs on throwing accuracy, proprioception, and core endurance in baseball.

PubMed

Lust, Kathleen R; Sandrey, Michelle A; Bulger, Sean M; Wilder, Nathan

2009-08-01

With a limited number of outcomes-based studies, only recommendations for strength-training and rehabilitation programs can be made. To determine the extent to which throwing accuracy, core stability, and proprioception improved after completion of a 6-week training program that included open kinetic chain (OKC), closed kinetic chain (CKC), and/or core-stability exercises. A 2 x 3 factorial design. Division III college. 19 healthy baseball athletes with a control group of 15. Two 6-week programs including OKC, CKC, and core-stabilization exercises that were progressed each week. Functional throwing-performance index, closed kinetic chain upper extremity stability test, back-extensor test, 45 degrees abdominal-fatigue test, and right- and left-side bridging test. There was no significant difference between groups. An increase was evident in all pretest-to-posttest results, with improvement ranging from 1.36% to 140%. Both of the 6-week training programs could be used to increase throwing accuracy, core stability, and proprioception in baseball.

Ultrasound-guided fine needle aspiration versus core needle biopsy: comparison of post-biopsy hematoma rates and risk factors.

PubMed

Chae, In Hye; Kim, Eun-Kyung; Moon, Hee Jung; Yoon, Jung Hyun; Park, Vivian Y; Kwak, Jin Young

2017-07-01

To compare post-biopsy hematoma rates between ultrasound guided-fine needle aspiration and ultrasound guided-core needle biopsy, and to investigate risk factors for post-biopsy hematoma. A total of 5304 thyroid nodules which underwent ultrasound guided biopsy were included in this retrospective study. We compared clinical and US features between patients with and without post-biopsy hematoma. Associations between these features and post-biopsy hematoma were analyzed. Post-biopsy hematoma rate was 0.8% (43/5121) for ultrasound guided-fine needle aspiration and 4.9% (9/183) for ultrasound guided-core needle biopsy (P < 0.001). For ultrasound guided-fine needle aspiration, gender, age, size, presence of vascularity, and suspicious US features were not associated with post-biopsy hematoma according to experience level. Post-biopsy hematoma occurred significantly more with ultrasound guided-core needle biopsy (9/179, 5.0%) than with ultrasound guided-fine needle aspiration (9/1138, 0.8%) (P < 0.001) in experienced performers and ultrasound guided-core needle biopsy was the only significant risk factor for post-biopsy hematoma (adjusted Odds Ratio, 6.458, P < 0.001). Post-biopsy hematoma occurred significantly more in ultrasound guided-core needle biopsy than in ultrasound guided-fine needle aspiration and ultrasound guided-core needle biopsy was the only independent factor of post-biopsy hematoma in thyroid nodules.

Conceptualization and Pilot Testing of a Core Competency-Based Training Workshop in Suicide Risk Assessment and Management: Notes From the Field.

PubMed

Cramer, Robert J; Bryson, Claire N; Eichorst, Morgam K; Keyes, Lee N; Ridge, Brittany E

2017-03-01

As professional psychology training programs and continuing education have moved toward competency based approaches, it has become equally important to develop uniform, evidence-based approaches for suicide risk assessment and management. The present article presents a workshop curriculum based on established core competencies in suicide risk assessment and management. Drawing on theories suicide risk formation, the workshop features an integration of didactic, process, and experiential components. We present pilot data from 2 small group workshops (n = 17): 1 from a clinical psychology doctoral program and 1 from a university counseling center. Workshop participation yielded increases in (a) the ability to recognize appropriate clinician responses to suicidal client statements, (b) self-perceptions of general capacity to interface with suicidal patients and mastery of the 10 core competencies, (c) factual knowledge concerning suicide risk assessment and management, and (d) the self-rated ability to assess and manage a suicidal patient. We discuss statistical and generalizability limitations as well as implications for future modification, implementation, and provision of this training method. © 2016 Wiley Periodicals, Inc.

Shock Initiated Reactions of Reactive Multiphase Blast Explosives

NASA Astrophysics Data System (ADS)

Wilson, Dennis; Granier, John; Johnson, Richard; Littrell, Donald

2015-06-01

This paper describes a new class of reactive multiphase blast explosives (RMBX) and characterization of their blast characteristics. These RMBXs are non-ideal explosive compositions of perfluoropolyether (PFPE), nano aluminum, and a micron-size high-density reactive metal - Tantalum, Zirconium, or Zinc in mass loadings of 66 to 83 percent. Unlike high explosives, these PFPE-metal compositions release energy via a fast self-oxidized combustion wave (rather than a true self-sustaining detonation) that is shock dependent, and can be overdriven to control energy release rate. The term ``reactive multiphase blast'' refers to the post-dispersion blast behavior: multiphase in that there are a gas phase that imparts pressure and a solid (particulate) phase that imparts momentum; and reactive in that the hot metal particles react with atmospheric oxygen and the explosive gas products to give an extended pressure pulse. The RMBX formulations were tested in two spherical core-shell geometries - an RMBX shell exploded by a high explosive core, and an RMBX core imploded by a high explosive shell. The fireball and blast characteristics were compared to a C-4 baseline charge.

Structural empowerment and burnout among Portuguese nursing staff: An explicative model.

PubMed

Orgambídez-Ramos, Alejandro; Borrego-Alés, Yolanda; Vázquez-Aguado, Octavio; March-Amegual, Jaume

2017-11-01

Kanter's structural empowerment model was used to assess the influence of access to opportunities, resources, information and support on core burnout through global empowerment in a nursing sample in Portugal. The empowerment experience increases the levels of nursing professionals' satisfaction and performance preventing the emergence of burnout. However, the relationship between structural empowerment and burnout has been scarcely studied in Portugal. We conducted a cross-sectional correlational study assessing a final sample of 297 participants (62.13% response rate, 63.64% women). Model fit and mediation test were examined using structural equation modelling (path analysis). Access to opportunities and access to support had direct impact, through global empowerment, on core burnout, whereas access to resources had both direct and indirect impact on core burnout. The results validated the structural empowerment model and its application in nursing staff in Portugal. Professional training plans, the development of formal and informal support networks, and the availability of resources increase the levels of empowerment and decrease the likelihood of experiencing burnout in nursing professionals. © 2017 John Wiley & Sons Ltd.

Ontogenetic scaling of metabolism, growth, and assimilation: testing metabolic scaling theory with Manduca sexta larvae.

PubMed

Sears, Katie E; Kerkhoff, Andrew J; Messerman, Arianne; Itagaki, Haruhiko

2012-01-01

Metabolism, growth, and the assimilation of energy and materials are essential processes that are intricately related and depend heavily on animal size. However, models that relate the ontogenetic scaling of energy assimilation and metabolism to growth rely on assumptions that have yet to be rigorously tested. Based on detailed daily measurements of metabolism, growth, and assimilation in tobacco hornworms, Manduca sexta, we provide a first experimental test of the core assumptions of a metabolic scaling model of ontogenetic growth. Metabolic scaling parameters changed over development, in violation of the model assumptions. At the same time, the scaling of growth rate matches that of metabolic rate, with similar scaling exponents both across and within developmental instars. Rates of assimilation were much higher than expected during the first two instars and did not match the patterns of scaling of growth and metabolism, which suggests high costs of biosynthesis early in development. The rapid increase in size and discrete instars observed in larval insect development provide an ideal system for understanding how patterns of growth and metabolism emerge from fundamental cellular processes and the exchange of materials and energy between an organism and its environment.

RELAP5 Analyses of OECD/NEA ROSA-2 Project Experiments on Intermediate-Break LOCAs at Hot Leg or Cold Leg

NASA Astrophysics Data System (ADS)

Takeda, Takeshi; Maruyama, Yu; Watanabe, Tadashi; Nakamura, Hideo

Experiments simulating PWR intermediate-break loss-of-coolant accidents (IBLOCAs) with 17% break at hot leg or cold leg were conducted in OECD/NEA ROSA-2 Project using the Large Scale Test Facility (LSTF). In the hot leg IBLOCA test, core uncovery started simultaneously with liquid level drop in crossover leg downflow-side before loop seal clearing (LSC) induced by steam condensation on accumulator coolant injected into cold leg. Water remained on upper core plate in upper plenum due to counter-current flow limiting (CCFL) because of significant upward steam flow from the core. In the cold leg IBLOCA test, core dryout took place due to rapid liquid level drop in the core before LSC. Liquid was accumulated in upper plenum, steam generator (SG) U-tube upflow-side and SG inlet plenum before the LSC due to CCFL by high velocity vapor flow, causing enhanced decrease in the core liquid level. The RELAP5/MOD3.2.1.2 post-test analyses of the two LSTF experiments were performed employing critical flow model in the code with a discharge coefficient of 1.0. In the hot leg IBLOCA case, cladding surface temperature of simulated fuel rods was underpredicted due to overprediction of core liquid level after the core uncovery. In the cold leg IBLOCA case, the cladding surface temperature was underpredicted too due to later core uncovery than in the experiment. These may suggest that the code has remaining problems in proper prediction of primary coolant distribution.

Psychometric properties of the Chinese version of the Pediatric Quality Of Life Inventory 4.0 Generic Core scales among pediatric cancer patients.

PubMed

Yeung, Nelson C Y; Lau, Joseph T F; Yu, Xiao-nan; Chu, Yvonne; Shing, Matthew M K; Leung, Ting Fan; Li, Chi Kong; Fok, Tai Fai; Mak, Winnie W S

2013-01-01

The Pediatric Quality of Life Inventory (PedsQL) 4.0 Generic Core Scales are commonly used to assess health-related quality of life of healthy children and pediatric patients. Validation of the Generic Core Scales among Chinese pediatric cancer patients has not been reported in the literature. The scales can serve to measure different quality-of-life domains that are not captured by the PedsQL Cancer Module. Psychometric properties of the Chinese version of the PedsQL 4.0 among pediatric cancer patients and their caretakers were examined. The Generic Core Scales were administered to 335 pairs of pediatric cancer patients (aged 8-18 years) and their caretakers in Hong Kong. A 5-factor structure (physical, emotional, social, school-related cognitive function, and missed school) was identified in the patient and proxy versions of the scales using confirmatory factor analysis. Both versions of the total scale reported Cronbach α's of .90 or greater, with almost all subscales reporting α's of .70 or greater. Test-retest reliability at 2 weeks was acceptable (intraclass correlations ≥0.60) for a majority of subscales. Agreement between patients' and caretakers' ratings was medium. The scales demonstrated acceptable psychometric properties and construct validity. This study validated the Chinese version of the Generic Core Scales among pediatric cancer patients and their caretakers, which supports the future use of the scales in clinical settings. The Generic Core Scales can also be supplementary to the PedsQL Cancer Module for measuring multiple domains of quality of life in cancer population.

Pebble Accretion in Turbulent Protoplanetary Disks

NASA Astrophysics Data System (ADS)

Xu, Ziyan; Bai, Xue-Ning; Murray-Clay, Ruth A.

2017-09-01

It has been realized in recent years that the accretion of pebble-sized dust particles onto planetary cores is an important mode of core growth, which enables the formation of giant planets at large distances and assists planet formation in general. The pebble accretion theory is built upon the orbit theory of dust particles in a laminar protoplanetary disk (PPD). For sufficiently large core mass (in the “Hill regime”), essentially all particles of appropriate sizes entering the Hill sphere can be captured. However, the outer regions of PPDs are expected to be weakly turbulent due to the magnetorotational instability (MRI), where turbulent stirring of particle orbits may affect the efficiency of pebble accretion. We conduct shearing-box simulations of pebble accretion with different levels of MRI turbulence (strongly turbulent assuming ideal magnetohydrodynamics, weakly turbulent in the presence of ambipolar diffusion, and laminar) and different core masses to test the efficiency of pebble accretion at a microphysical level. We find that accretion remains efficient for marginally coupled particles (dimensionless stopping time {τ }s˜ 0.1{--}1) even in the presence of strong MRI turbulence. Though more dust particles are brought toward the core by the turbulence, this effect is largely canceled by a reduction in accretion probability. As a result, the overall effect of turbulence on the accretion rate is mainly reflected in the changes in the thickness of the dust layer. On the other hand, we find that the efficiency of pebble accretion for strongly coupled particles (down to {τ }s˜ 0.01) can be modestly reduced by strong turbulence for low-mass cores.

Laboratory ultrasonic pulse velocity logging for determination of elastic properties from rock core

NASA Astrophysics Data System (ADS)

Blacklock, Natalie Erin

During the development of deep underground excavations spalling and rockbursting have been recognized as significant mechanisms of violent brittle failure. In order to predict whether violent brittle failure will occur, it is important to identify the location of stiffness transitions that are associated with geologic structure. One approach to identify the effect of geologic structures is to apply borehole geophysical tools ahead of the tunnel advance. Stiffness transitions can be identified using mechanical property analysis surveys that combine acoustic velocity and density data to calculate acoustic estimates of elastic moduli. However, logistical concerns arise since the approach must be conducted at the advancing tunnel face. As a result, borehole mechanical property analyses are rarely used. Within this context, laboratory ultrasonic pulse velocity testing has been proposed as a potential alternative to borehole mechanical property analysis since moving the analysis to the laboratory would remove logistical constraints and improve safety for the evaluators. In addition to the traditional method of conducting velocity testing along the core axis, two new methodologies for point-focused testing were developed across the core diameter, and indirectly along intact lengths of drill core. The indirect test procedure was implemented in a continuous ultrasonic velocity test program along 573m of drill core to identify key geologic structures that generated transitions in ultrasonic elastic moduli. The test program was successful at identifying the location of geologic contacts, igneous intrusions, faults and shear structures. Ultrasonic values of Young's modulus and bulk modulus were determined at locations of significant velocity transitions to examine the potential for energy storage and energy release. Comparison of results from different ultrasonic velocity test configurations determined that the indirect test configuration provided underestimates for values of Young's modulus. This indicated that the test procedure will require modifications to improve coupling of the transducers to the core surface. In order to assess whether laboratory testing can be an alternative to borehole surveys, laboratory velocity testing must be directly assessed with results from acoustic borehole logging. There is also potential for the laboratory velocity program to be used to assess small scale stiffness changes, differences in mineral composition and the degree of fracturing of drill core.

A hybrid rocket engine design for simple low cost sounding rocket use

NASA Astrophysics Data System (ADS)

Grubelich, Mark; Rowland, John; Reese, Larry

1993-06-01

Preliminary test results on a nitrous oxide/HTPB hybrid rocket engine suitable for powering a small sounding rocket to altitudes of 50-100 K/ft are presented. It is concluded that the advantage of the N2O hybrid engine over conventional solid propellant rocket motors is the ability to obtain long burn times with core burning geometries due to the low regression rate of the fuel. Long burn times make it possible to reduce terminal velocity to minimize air drag losses.

Particle bed reactor modeling

NASA Technical Reports Server (NTRS)

Sapyta, Joe; Reid, Hank; Walton, Lew

1993-01-01

The topics are presented in viewgraph form and include the following: particle bed reactor (PBR) core cross section; PBR bleed cycle; fuel and moderator flow paths; PBR modeling requirements; characteristics of PBR and nuclear thermal propulsion (NTP) modeling; challenges for PBR and NTP modeling; thermal hydraulic computer codes; capabilities for PBR/reactor application; thermal/hydralic codes; limitations; physical correlations; comparison of predicted friction factor and experimental data; frit pressure drop testing; cold frit mask factor; decay heat flow rate; startup transient simulation; and philosophy of systems modeling.

Simulation numerique de l'effet du reflecteur radial sur les cellules rep en utilisant les codes DRAGON et DONJON

NASA Astrophysics Data System (ADS)

Bejaoui, Najoua

The pressurized water nuclear reactors (PWRs) is the largest fleet of nuclear reactors in operation around the world. Although these reactors have been studied extensively by designers and operators using efficient numerical methods, there are still some calculation weaknesses, given the geometric complexity of the core, still unresolved such as the analysis of the neutron flux's behavior at the core-reflector interface. The standard calculation scheme is a two steps process. In the first step, a detailed calculation at the assembly level with reflective boundary conditions, provides homogenized cross-sections for the assemblies, condensed to a reduced number of groups; this step is called the lattice calculation. The second step uses homogenized properties in each assemblies to calculate reactor properties at the core level. This step is called the full-core calculation or whole-core calculation. This decoupling of the two calculation steps is the origin of methodological bias particularly at the interface core reflector: the periodicity hypothesis used to calculate cross section librairies becomes less pertinent for assemblies that are adjacent to the reflector generally represented by these two models: thus the introduction of equivalent reflector or albedo matrices. The reflector helps to slowdown neutrons leaving the reactor and returning them to the core. This effect leads to two fission peaks in fuel assemblies localised at the core/reflector interface, the fission rate increasing due to the greater proportion of reentrant neutrons. This change in the neutron spectrum arises deep inside the fuel located on the outskirts of the core. To remedy this we simulated a peripheral assembly reflected with TMI-PWR reflector and developed an advanced calculation scheme that takes into account the environment of the peripheral assemblies and generate equivalent neutronic properties for the reflector. This scheme is tested on a core without control mechanisms and charged with fresh fuel. The results of this study showed that explicit representation of reflector and calculation of peripheral assembly with our advanced scheme allow corrections to the energy spectrum at the core interface and increase the peripheral power by up to 12% compared with that of the reference scheme.

A dissolution model that accounts for coverage of mineral surfaces by precipitation in core floods

NASA Astrophysics Data System (ADS)

Pedersen, Janne; Jettestuen, Espen; Madland, Merete V.; Hildebrand-Habel, Tania; Korsnes, Reidar I.; Vinningland, Jan Ludvig; Hiorth, Aksel

2016-01-01

In this paper, we propose a model for evolution of reactive surface area of minerals due to surface coverage by precipitating minerals. The model is used to interpret results from an experiment where a chalk core was flooded with MgCl2 for 1072 days, giving rise to calcite dissolution and magnesite precipitation. The model successfully describes both the long-term behavior of the measured effluent concentrations and the more or less homogeneous distribution of magnesite found in the core after 1072 days. The model also predicts that precipitating magnesite minerals form as larger crystals or aggregates of smaller size crystals, and not as thin flakes or as a monomolecular layer. Using rate constants obtained from literature gave numerical effluent concentrations that diverged from observed values only after a few days of flooding. To match the simulations to the experimental data after approximately 1 year of flooding, a rate constant that is four orders of magnitude lower than reported by powder experiments had to be used. We argue that a static rate constant is not sufficient to describe a chalk core flooding experiment lasting for nearly 3 years. The model is a necessary extension of standard rate equations in order to describe long term core flooding experiments where there is a large degree of textural alteration.

Inner core rotation from event-pair analysis

NASA Astrophysics Data System (ADS)

Song, Xiaodong; Poupinet, Georges

2007-09-01

The last decade has witnessed an animated debate on whether the inner core rotation is a fact or an artifact. Here we examine the temporal change of inner core waves using a technique that compares differential travel times at the same station but between two events. The method does not require precise knowledge of earthquake locations and earth models. The pairing of the events creates a large data set for the application of statistical tools. Using measurements from 87 events in the South Sandwich Islands recorded at College, Alaska station, we conclude the temporal change is robust. The estimates of the temporal change range from about 0.07 to 0.10 s/decade over the past 50 yr. If we used only pairs with small inter-event distances, which reduce the influence of mantle heterogeneity, the rates range from 0.084 to 0.098 s/decade, nearly identical to the rate inferred by Zhang et al. [Zhang, J., Song, X.D., Li, Y.C., Richards, P.G., Sun, X.L., Waldhauser, F., Inner core differential motion confirmed by earthquake waveform doublets, Science 309 (5739) (2005) 1357-1360.] from waveform doublets. The rate of the DF change seems to change with time, which may be explained by lateral variation of the inner core structure or the change in rotation rate on decadal time scale.

Core-shell-structured nanothermites synthesized by atomic layer deposition

NASA Astrophysics Data System (ADS)

Qin, Lijun; Gong, Ting; Hao, Haixia; Wang, Keyong; Feng, Hao

2013-12-01

Thermite materials feature very exothermic solid-state redox reactions. However, the energy release rates of traditional thermite mixtures are limited by the reactant diffusion velocities. In this work, atomic layer deposition (ALD) is utilized to synthesize thermite materials with greatly enhanced reaction rates. By depositing certain types of metal oxides (oxidizers) onto a commercial Al nanopowder, core-shell-structured nanothermites can be produced. The average film deposition rate on the Al nanopowder is 0.17 nm/cycle for ZnO and 0.031 nm/cycle for SnO2. The thickness of the oxidizer layer can be precisely controlled by adjusting the ALD cycle number. The compositions, morphologies, and structures of the ALD nanothermites are characterized by X-ray photoelectron spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy. The characterization results reveal nearly perfect coverage of the Al nanoparticles by uniform ALD oxidizer layers and confirm the formation of core-shell nanoparticles. Combustion properties of the nanothermites are probed by laser ignition technique. Reactions of the core-shell-structured nanothermites are several times faster than the mixture of nanopowders. The promoted reaction rate is mostly attributed to the uniform distribution of reactants on the nanometer scale. These core-shell-structured nanothermites provide a potential pathway to control and enhance thermite reactions.

Publications - GMC 412 | Alaska Division of Geological & Geophysical

Science.gov Websites

Spectrometer) data of core from the East Simpson Test Well #1, Ikpikpuk Test Well #1, Inigok Test Well #1, and Peard Test Well #1 wells Authors: Gottlieb, E. Publication Date: Nov 2012 Publisher: Alaska Division of , LaserChron (Nu Instruments High Resolution ICP Mass Spectrometer) data of core from the East Simpson Test

Narcotics reduction, quality and safety in gynecologic oncology surgery in the first year of enhanced recovery after surgery protocol implementation.

PubMed

Bergstrom, Jennifer E; Scott, Marla E; Alimi, Yewande; Yen, Ting-Tai; Hobson, Deborah; Machado, Karime K; Tanner, Edward J; Fader, Amanda N; Temkin, Sarah M; Wethington, Stephanie; Levinson, Kimberly; Sokolinsky, Sam; Lau, Brandyn; Stone, Rebecca L

2018-06-01

Enhanced Recovery After Surgery (ERAS) programs are mechanisms for achieving value-based improvements in surgery. This report provides a detailed analysis of the impact of an ERAS program on patient outcomes as well as quality and safety measures during implementation on a gynecologic oncology service at a major academic medical center. A retrospective review of gynecologic oncology patients undergoing elective laparotomy during the implementation phase of an ERAS program (January 2016 through December 2016) was performed. Patient demographics, surgical variables, postoperative outcomes, and adherence to core safety measures, including antimicrobial and venous thromboembolism (VTE) prophylaxis, were compared to a historical patient cohort (January 2015 through December 2015). Statistical analyses were performed using t-tests, Wilcoxon rank sum tests, and Chi squared tests. The inaugural 109 ERAS program participants were compared to a historical patient cohort (n=158). There was no difference in BMI, race, malignancy, or complexity of procedure between cohorts. ERAS patients required less narcotics (70.7 vs 127.4, p=0.007, oral morphine equivalents) and PCA use (32.1% vs. 50.6%, p=0.002). Despite this substantial reduction in narcotics, ERAS patients did not report more pain and in fact reported significantly less pain by postoperative day 3. There were no differences in length of stay (5days), complication rates (13.8% vs. 20.3%, p=0.17) or 30-day readmission rates (9.5 vs 11.9%, p=0.54) between ERAS and historical patients, respectively. Compliance with antimicrobial prophylaxis was 97.2%. However, 33.9% of ERAS patients received substandard preoperative VTE prophylaxis. ERAS program implementation resulted in reductions in narcotic requirements and PCA use without changes in length of stay or readmission rates. Compliance should be diligently audited during the implementation phase of ERAS programs, with special attention to adherence to pre-existing core safety measures. Copyright © 2018 Elsevier Inc. All rights reserved.

Antarctic Testing of the European Ultrasonic Planetary Core Drill (UPCD)

NASA Astrophysics Data System (ADS)

Timoney, R.; Worrall, K.; Li, X.; Firstbrook, D.; Harkness, P.

2018-04-01

An overview of a series of field testing in Antarctica where the Ultrasonic Planetary Core Drill (UPCD) architecture was tested. The UPCD system is the product an EC FP7 award to develop a Mars Sample Return architecture based around the ultrasonic technique.

Impact of HFIR LEU Conversion on Beryllium Reflector Degradation Factors

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

Ilas, Dan

2013-10-01

An assessment of the impact of low enriched uranium (LEU) conversion on the factors that may cause the degradation of the beryllium reflector is performed for the High Flux Isotope Reactor (HFIR). The computational methods, models, and tools, comparisons with previous work, along with the results obtained are documented and discussed in this report. The report documents the results for the gas and neutronic poison production, and the heating in the beryllium reflector for both the highly enriched uranium (HEU) and LEU HFIR configurations, and discusses the impact that the conversion to LEU may have on these quantities. A time-averagingmore » procedure was developed to calculate the isotopic (gas and poisons) production in reflector. The sensitivity of this approach to different approximations is gauged and documented. The results show that the gas is produced in the beryllium reflector at a total rate of 0.304 g/cycle for the HEU configuration; this rate increases by ~12% for the LEU case. The total tritium production rate in reflector is 0.098 g/cycle for the HEU core and approximately 11% higher for the LEU core. A significant increase (up to ~25%) in the neutronic poisons production in the reflector during the operation cycles is observed for the LEU core, compared to the HEU case, for regions close to the core s horizontal midplane. The poisoning level of the reflector may increase by more than two orders of magnitude during long periods of downtime. The heating rate in the reflector is estimated to be approximately 20% lower for the LEU core than for the HEU core. The decrease is due to a significantly lower contribution of the heating produced by the gamma radiation for the LEU core. Both the isotopic (gas and neutronic poisons) production and the heating rates are spatially non-uniform throughout the beryllium reflector volume. The maximum values typically occur in the removable reflector and close to the midplane.« less

Static and Wind Tunnel Aero-Performance Tests of NASA AST Separate Flow Nozzle Noise Reduction Configurations

NASA Technical Reports Server (NTRS)

Mikkelsen, Kevin L.; McDonald, Timothy J.; Saiyed, Naseem (Technical Monitor)

2001-01-01

This report presents the results of cold flow model tests to determine the static and wind tunnel performance of several NASA AST separate flow nozzle noise reduction configurations. The tests were conducted by Aero Systems Engineering, Inc., for NASA Glenn Research Center. The tests were performed in the Channels 14 and 6 static thrust stands and the Channel 10 transonic wind tunnel at the FluiDyne Aerodynamics Laboratory in Plymouth, Minnesota. Facility checkout tests were made using standard ASME long-radius metering nozzles. These tests demonstrated facility data accuracy at flow conditions similar to the model tests. Channel 14 static tests reported here consisted of 21 ASME nozzle facility checkout tests and 57 static model performance tests (including 22 at no charge). Fan nozzle pressure ratio varied from 1.4 to 2.0, and fan to core total pressure ratio varied from 1.0 to 1.19. Core to fan total temperature ratio was 1.0. Channel 10 wind tunnel tests consisted of 15 tests at Mach number 0.28 and 31 tests at Mach 0.8. The sting was checked out statically in Channel 6 before the wind tunnel tests. In the Channel 6 facility, 12 ASME nozzle data points were taken and 7 model data points were taken. In the wind tunnel, fan nozzle pressure ratio varied from 1.73 to 2.8, and fan to core total pressure ratio varied from 1.0 to 1.19. Core to fan total temperature ratio was 1.0. Test results include thrust coefficients, thrust vector angle, core and fan nozzle discharge coefficients, total pressure and temperature charging station profiles, and boat-tail static pressure distributions in the wind tunnel.

The novel nomogram of Gleason sum upgrade: possible application for the eligible criteria of low dose rate brachytherapy.

PubMed

Budäus, Lars; Graefen, Markus; Salomon, Georg; Isbarn, Hendrik; Lughezzani, Giovanni; Sun, Maxine; Chun, Felix K H; Schlomm, Thorsten; Steuber, Thomas; Haese, Alexander; Koellermann, Jens; Sauter, Guido; Fisch, Margit; Heinzer, Hans; Huland, Hartwig; Karakiewicz, Pierre I

2010-10-01

To examine the rate of Gleason sum upgrading (GSU) from a sum of 6 to a Gleason sum of ≥7 in patients undergoing radical prostatectomy (RP), who fulfilled the recommendations for low dose rate brachytherapy (Gleason sum 6, prostate-specific antigen ≤10 ng/mL, clinical stage ≤T2a and prostate volume ≤50 mL), and to test the performance of an existing nomogram for prediction of GSU in this specific cohort of patients. The analysis focused on 414 patients, who fulfilled the European Society for Therapeutic Radiation and Oncology and American Brachytherapy Society criteria for low dose rate brachytherapy (LD-BT) and underwent a 10-core prostate biopsy followed by RP. The rate of GSU was tabulated and the ability of available clinical and pathological parameters for predicting GSU was tested. Finally, the performance of an existing GSU nomogram was explored. The overall rate of GSU was 35.5%. When applied to LD-BT candidates, the existing nomogram was 65.8% accurate versus 70.8% for the new nomogram. In decision curve analysis tests, the new nomogram fared substantially better than the assumption that no patient is upgraded and better than the existing nomogram. GSU represents an important issue in LD-BT candidates. The new nomogram might improve patient selection for LD-BT and cancer control outcome by excluding patients with an elevated probability of GSU. © 2010 The Japanese Urological Association.

Carbon and sediment accumulation in the Everglades (USA) during the past 4000 years: rates, drivers, and sources of error

USGS Publications Warehouse

Glaser, Paul H.; Volin, John C.; Givnish, Thomas J.; Hansen, Barbara C. S.; Stricker, Craig A.

2012-01-01

Tropical and sub-tropical wetlands are considered to be globally important sources for greenhouse gases but their capacity to store carbon is presumably limited by warm soil temperatures and high rates of decomposition. Unfortunately, these assumptions can be difficult to test across long timescales because the chronology, cumulative mass, and completeness of a sedimentary profile are often difficult to establish. We therefore made a detailed analysis of a core from the principal drainage outlet of the Everglades of South Florida, to assess these problems and determine the factors that could govern carbon accumulation in this large sub-tropical wetland. Accelerator mass spectroscopy dating provided direct evidence for both hard-water and open-system sources of dating errors, whereas cumulative mass varied depending upon the type of method used. Radiocarbon dates of gastropod shells, nevertheless, seemed to provide a reliable chronology for this core once the hard-water error was quantified and subtracted. Long-term accumulation rates were then calculated to be 12.1 g m-2 yr-1 for carbon, which is less than half the average rate reported for northern and tropical peatlands. Moreover, accumulation rates remained slow and relatively steady for both organic and inorganic strata, and the slow rate of sediment accretion ( 0.2 mm yr-1) tracked the correspondingly slow rise in sea level (0.35 mm yr-1 ) reported for South Florida over the past 4000 years. These results suggest that sea level and the local geologic setting may impose long-term constraints on rates of sediment and carbon accumulation in the Everglades and other wetlands.

Permeability, porosity, and mineral surface area changes in basalt cores induced by reactive transport of CO2-rich brine

NASA Astrophysics Data System (ADS)

Luhmann, Andrew J.; Tutolo, Benjamin M.; Bagley, Brian C.; Mildner, David F. R.; Seyfried, William E.; Saar, Martin O.

2017-03-01

Four reactive flow-through laboratory experiments (two each at 0.1 mL/min and 0.01 mL/min flow rates) at 150°C and 150 bar (15 MPa) are conducted on intact basalt cores to assess changes in porosity, permeability, and surface area caused by CO2-rich fluid-rock interaction. Permeability decreases slightly during the lower flow rate experiments and increases during the higher flow rate experiments. At the higher flow rate, core permeability increases by more than one order of magnitude in one experiment and less than a factor of two in the other due to differences in preexisting flow path structure. X-ray computed tomography (XRCT) scans of pre- and post-experiment cores identify both mineral dissolution and secondary mineralization, with a net decrease in XRCT porosity of ˜0.7%-0.8% for the larger pores in all four cores. (Ultra) small-angle neutron scattering ((U)SANS) data sets indicate an increase in both (U)SANS porosity and specific surface area (SSA) over the ˜1 nm to 10 µm scale range in post-experiment basalt samples, with differences due to flow rate and reaction time. Net porosity increases from summing porosity changes from XRCT and (U)SANS analyses are consistent with core mass decreases. (U)SANS data suggest an overall preservation of the pore structure with no change in mineral surface roughness from reaction, and the pore structure is unique in comparison to previously published basalt analyses. Together, these data sets illustrate changes in physical parameters that arise due to fluid-basalt interaction in relatively low pH environments with elevated CO2 concentration, with significant implications for flow, transport, and reaction through geologic formations.

Are concurrent systematic cores needed at the time of targeted biopsy in patients with prior negative prostate biopsies?

PubMed

Albisinni, S; Aoun, F; Noel, A; El Rassy, E; Lemort, M; Paesmans, M; van Velthoven, R; Roumeguère, T; Peltier, A

2018-01-01

MRI-guided targeted biopsies are advised in patients who have undergone an initial series of negative systematic biopsies, in whom prostate cancer (PCa) suspicion remains elevated. The aim of the study was to evaluate whether, in men with prior negative prostate biopsies, systematic cores are also warranted at the time of an MRI-targeted repeat biopsy. We enrolled patients with prior negative biopsy undergoing real time MRI/TRUS fusion guided prostate biopsy at our institute between 2014 and 2016. Patients with at least one index lesion on multiparametric MRI were included. All eligible patients underwent both systematic random biopsies (12-14 cores) and targeted biopsies (2-4 cores). The study included 74 men with a median age of 65 years, PSA level of 9.27ng/mL, and prostatic volume of 45ml. The overall PCa detection rate and the clinically significant cancer detection rate were 56.7% and 39.2%, respectively. Targeted cores demonstrated similar clinically significant PCa detection rate compared to systematic cores (33.8% vs. 28.4%, P=0.38) with significantly less tissue sampling. Indeed, a combination approach was significantly superior to a targeted-only in overall PCa detection (+16.7% overall detection rate, P=0.007). Although differences in clinically significant PCa detection were statistically non-significant (P=0.13), a combination approach did allow detecting 7 extra clinically significant PCas (+13.8%). In patients with elevated PSA and prior negative biopsies, concurrent systematic sampling may be needed at the time of targeted biopsy in order to maximize PCa detection rate. Larger studies are needed to validate our findings. 4. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Impact and Blast Resistance of Sandwich Plates

NASA Astrophysics Data System (ADS)

Dvorak, George J.; Bahei-El-Din, Yehia A.; Suvorov, Alexander P.

Response of conventional and modified sandwich plate designs is examined under static load, impact by a rigid cylindrical or flat indenter, and during and after an exponential pressure impulse lasting for 0.05 ms, at peak pressure of 100 MPa, simulating a nearby explosion. The conventional sandwich design consists of thin outer (loaded side) and inner facesheets made of carbon/epoxy fibrous laminates, separated by a thick layer of structural foam core. In the three modified designs, one or two thin ductile interlayers are inserted between the outer facesheet and the foam core. Materials selected for the interlayers are a hyperelas-tic rate-independent polyurethane;a compression strain and strain rate dependent, elastic-plastic polyurea;and an elastomeric foam. ABAQUS and LS-Dyna software were used in various response simulations. Performance comparisons between the enhanced and conventional designs show that the modified designs provide much better protection against different damage modes under both load regimes. After impact, local facesheet deflection, core compression, and energy release rate of delamination cracks, which may extend on hidden interfaces between facesheet and core, are all reduced. Under blast or impulse loads, reductions have been observed in the extent of core crushing, facesheet delaminations and vibration amplitudes, and in overall deflections. Similar reductions were found in the kinetic energy and in the stored and dissipated strain energy. Although strain rates as high as 10-4/s1 are produced by the blast pressure, peak strains in the interlayers were too low to raise the flow stress in the polyurea to that in the polyurethane, where a possible rate-dependent response was neglected. Therefore, stiff polyurethane or hard rubber interlayers materials should be used for protection of sandwich plate foam cores against both impact and blast-induced damage.

Holocene Accumulation and Ice Flow near the West Antarctic Ice Sheet Divide Ice Core Site

NASA Technical Reports Server (NTRS)

Koutnik, Michelle R.; Fudge, T.J.; Conway, Howard; Waddington, Edwin D.; Neumann, Thomas A.; Cuffey, Kurt M.; Buizert, Christo; Taylor, Kendrick C.

2016-01-01

The West Antarctic Ice Sheet Divide Core (WDC) provided a high-resolution climate record from near the Ross-Amundsen Divide in Central West Antarctica. In addition, radar-detected internal layers in the vicinity of the WDC site have been dated directly from the ice core to provide spatial variations in the age structure of the region. Using these two data sets together, we first infer a high-resolution Holocene accumulation-rate history from 9.2 thousand years of the ice-core timescale and then confirm that this climate history is consistent with internal layers upstream of the core site. Even though the WDC was drilled only 24 kilometers from the modern ice divide, advection of ice from upstream must be taken into account. We evaluate histories of accumulation rate by using a flowband model to generate internal layers that we compare to observed layers. Results show that the centennially averaged accumulation rate was over 20 percent lower than modern at 9.2 thousand years before present (B.P.), increased by 40 percent from 9.2 to 2.3 thousand years B.P., and decreased by at least 10 percent over the past 2 thousand years B.P. to the modern values; these Holocene accumulation-rate changes in Central West Antarctica are larger than changes inferred from East Antarctic ice-core records. Despite significant changes in accumulation rate, throughout the Holocene the regional accumulation pattern has likely remained similar to today, and the ice-divide position has likely remained on average within 5 kilometers of its modern position. Continent-scale ice-sheet models used for reconstructions of West Antarctic ice volume should incorporate this accumulation history.

Mercury accumulation in Devils Lake, North Dakota effects of environmental variation in closed-basin lakes on mercury chronologies

USGS Publications Warehouse

Lent, R.M.; Alexander, C.R.

1997-01-01

Sediment cores were collected from lakes in the Devils Lake Basin in North Dakota to determine if mercury (Hg) accumulation chronologies from sediment-core data are good indicators of variations in Hg accumulation rates in saline lakes. Sediment cores from Creel Bay and Main Bay, Devils Lake were selected for detailed analysis and interpretation. The maximum Hg concentration in the Creel Bay core was 0.15 micrograms per gram at 8 to 9 centimeters. The maximum Hg concentration in the Main Bay core was 0.07 micrograms per gram at 5 to 7 centimeters. The general decreases in Hg concentrations with depth are attributed to historic variations in atmospheric Hg deposition rate. Hg stratigraphies combined with 210Pb and 137Cs dating analyses yield Hg chronologies that indicate a general increase in Hg accumulation rates in Devils Lake since the middle of the 19th century. Mean modern Hg accumulation rates in Creel Bay were 4.9 nanograms per square centimeter per year, and rates in Main Bay were 1.8 nanograms per square centimeter per year. Mean preindustrial Hg accumulation rates in Creel Bay were 1.2 nanograms per square centimeter per year, and rates in Main Bay were 1.6 nanograms per square centimeter per year. Relatively low Hg concentrations in recent sediments in the Devils Lake Basin, along with similarities in Hg accumulation rates between lakes in the Devils Lake Basin and other lakes in the northern interior of North America, indicate that local sources of Hg are not important sources of Hg. Results of the study indicate that accurate Hg chronologies are discernible in sediment cores collected from saline lakes. However, spatial and temporal variations in lake level and water chemistry common to saline lakes make interpretation of radioisotopic and geochemical chronologies difficult. Hg geochemistry in Devils Lake, and presumably in other saline lakes, is dynamic. The results of this study indicate that the absolute amount of sediment transported to Devils Lake, along with the associated Hg and total organic carbon, and the distribution of sedimentation patterns in Devils Lake may be affected by changing lake levels.

International consensus on preliminary definitions of improvement in adult and juvenile myositis.

PubMed

Rider, Lisa G; Giannini, Edward H; Brunner, Hermine I; Ruperto, Nicola; James-Newton, Laura; Reed, Ann M; Lachenbruch, Peter A; Miller, Frederick W

2004-07-01

To use a core set of outcome measures to develop preliminary definitions of improvement for adult and juvenile myositis as composite end points for therapeutic trials. Twenty-nine experts in the assessment of myositis achieved consensus on 102 adult and 102 juvenile paper patient profiles as clinically improved or not improved. Two hundred twenty-seven candidate definitions of improvement were developed using the experts' consensus ratings as a gold standard and their judgment of clinically meaningful change in the core set of measures. Seventeen additional candidate definitions of improvement were developed from classification and regression tree analysis, a data-mining decision tree tool analysis. Six candidate definitions specifying percentage change or raw change in the core set of measures were developed using logistic regression analysis. Adult and pediatric working groups ranked the 13 top-performing candidate definitions for face validity, clinical sensibility, and ease of use, in which the sensitivity and specificity were >/=75% in adult, pediatric, and combined data sets. Nominal group technique was used to facilitate consensus formation. The definition of improvement (common to the adult and pediatric working groups) that ranked highest was 3 of any 6 of the core set measures improved by >/=20%, with no more than 2 worse by >/=25% (which could not include manual muscle testing to assess strength). Five and 4 additional preliminary definitions of improvement for adult and juvenile myositis, respectively, were also developed, with several definitions common to both groups. Participants also agreed to prospectively test 6 logistic regression definitions of improvement in clinical trials. Consensus preliminary definitions of improvement were developed for adult and juvenile myositis, and these incorporate clinically meaningful change in all myositis core set measures in a composite end point. These definitions require prospective validation, but they are now proposed for use as end points in all myositis trials.

Six weeks of core stability training improves landing kinetics among female capoeira athletes: a pilot study.

PubMed

Araujo, Simone; Cohen, Daniel; Hayes, Lawrence

2015-03-29

Core stability training (CST) has increased in popularity among athletes and the general fitness population despite limited evidence CST programmes alone lead to improved athletic performance. In female athletes, neuromuscular training combining balance training and trunk and hip/pelvis dominant CST is suggested to reduce injury risk, and specifically peak vertical ground reaction forces (vGRF) in a drop jump landing task. However, the isolated effect of trunk dominant core stability training on vGRF during landing in female athletes had not been evaluated. Therefore, the objective of this study was to evaluate landing kinetics during a drop jump test following a CST intervention in female capoeira athletes. After giving their informed written consent, sixteen female capoeira athletes (mean ± SD age, stature, and body mass of 27.3 ± 3.7 years, 165.0 ± 4.0 cm, and 59.7 ± 6.3 kg, respectively) volunteered to participate in the training program which consisted of static and dynamic CST sessions, three times per week for six weeks. The repeated measures T-test revealed participants significantly reduced relative vGRF from pre- to post-intervention for the first (3.40 ± 0.78 vs. 2.85 ± 0.52 N·NBW-1, respectively [p<0.05, effect size = 0.60]), and second landing phase (5.09 ± 1.17 vs. 3.02 ± 0.41 N·NBW-1, respectively [p<0.001, effect size = 0.87]). The average loading rate was reduced from pre- to post-intervention during the second landing phase (30.96 ± 18.84 vs. 12.06 ± 9.83 N·NBW·s-1, respectively [p<0.01, effect size = 0.68]). The peak loading rate was reduced from pre- to post-intervention during the first (220.26 ± 111.51 vs. 120.27 ± 64.57 N·NBW·s-1 respectively [p<0.01, effect size = 0.64]), and second (99.52 ± 54.98 vs. 44.71 ± 30.34 N·NBW·s-1 respectively [p<0.01, effect size = 0.70]) landing phase. Body weight, average loading rate during the first landing phase, and jump height were not significantly different between week 0 and week 6 (p=0.528, p=0.261, and p=0.877, respectively). This study provides evidence that trunk dominant core stability training improves landing kinetics without improving jump height, and may reduce lower extremity injury risk in female athletes.

CT-guided transthoracic needle biopsy: a comparison between automated biopsy gun and fine needle aspiration.

PubMed

Arakawa, H; Nakajima, Y; Kurihara, Y; Niimi, H; Ishikawa, T

1996-07-01

We retrospectively investigated the diagnostic accuracy and complication rate of transthoracic core biopsy using an automated biopsy gun and compared the findings with those of aspiration needle biopsy. Seventy-three patients underwent 74 core biopsy procedures and 50 patients underwent 52 aspiration biopsy procedures. Of these, a final diagnosis was obtained in 107 lesions with surgery or clinical course. Fifteen patients in which a final diagnosis was not obtained were excluded from the study on diagnostic accuracy. Thus, in the study of diagnostic accuracy, 63 core biopsy procedures for 62 lesions are included. Core biopsy was performed with an 18 G cutting needle using an automated biopsy gun. Aspiration biopsy was performed with a 20 G aspiration needle. Core biopsy yielded sufficient material in 57/63 procedures (90.5%). A correct diagnosis was obtained in 36 procedures (85.7%) for malignant leisons and a specific benign diagnosis was obtained in 11 procedures (52.4%). Aspiration biopsy yielded a correct diagnosis in 26 procedures (81.3%) for malignant leisons and in seven (46.7%) for benign lesions. The overall correct diagnosis were 75.8% and 71.7% with core biopsy and aspiration biopsy, respectively. Core biopsy gave a higher predictive rate than that of aspiration biopsy for both benign and malignant lessons (P < 0.02). Pneumothorax occurred in 18/74 (24.3%) patients with core biopsy and in 18/45 (40.0%) patients with aspiration biopsy. Of these, three with core biopsy and two with aspiration biopsy needed tube drainage. The other complication was haemoptysis, which occurred in six patients following core biopsy and in three after aspiration biopsy. All nine cases subsided spontaneously. There were no fatal complications. Core biopsy with a biopsy gun increase the diagnostic accuracy with a higher histologic predictive rate and no obvious additional risk of complications.

Utility of bioassays (lettuce, red clover, red fescue, Microtox, MetSTICK, Hyalella, bait lamina) in ecological risk screening of acid metal (Zn) contaminated soil.

PubMed

Chapman, E Emily V; Hedrei Helmer, Stephanie; Dave, Göran; Murimboh, John D

2012-06-01

The objective of this study was to assess selected bioassays and ecological screening tools for their suitability in a weight of evidence risk screening process of acidic metal contaminated soil. Intact soil cores were used for the tests, which minimizes changes in pH and metal bioavailability that may result from homogenization and drying of the soil. Soil cores were spiked with ZnCl(2) or CaCl(2). Leachate collected from the soil cores was used to account for the exposure pathways through pore water and groundwater. Tests assessed included MetSTICK in soil cores and Microtox in soil leachate, lettuce (Lactuca sativa), red fescue (Festuca rubra) and red clover (Trifolium pratense) in the soil cores and lettuce and red clover in soil leachate, Hyallella azteca in soil leachate, and an ecological soil function test using Bait Lamina in soil cores. Microtox, H. azteca, lettuce and red fescue showed higher sensitivity to low pH than to Zn concentrations and are therefore not recommended as tests on intact acidic soil cores and soil leachate. The Bait Lamina test appeared sensitive to pH levels below 3.7 but should be investigated further as a screening tool in less acidic soils. Among the bioassays, the MetSTICK and the T. pratense bioassays in soil cores were the most sensitive to Zn, with the lowest nominal NOEC of 200 and 400mg Zn/kg d.w., respectively. These bioassays were also tolerant of low pH, which make them suitable for assessing hazards of metal contaminated acid soils. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of an adhesive resin luting agent on the dowel-head retention of three different core materials.

PubMed

Aksoy, Gokhan; Cotert, H Serdar; Korkut, Levent

2005-05-01

A dowel-and-core restoration may fail due to failure at either the dowel-tooth or dowel head-core material interface. Long-term clinical success of a dowel-and-core restoration depends on retention of both the dowel to the tooth and the dowel head to the core material. Thus, strengthening of the dowel head-core interface is important. This study evaluated the retention between a prefabricated dowel and 3 different core materials with or without a dual-polymerized adhesive resin luting agent. Sixty prefabricated dowels (Gold Plated Anchorage Post) were divided into 3 groups (n=20) consisting of 1 of 3 core materials, amalgam (Standalloy F), light-polymerized resin composite (Clearfil Ray), or glass ionomer (Chelon-Silver). Each core group was divided into 2 subgroups (n=10), and a dual-polymerized adhesive resin luting agent (Panavia F) was applied to the dowel heads of 1 of these subgroups before application of the core material. The manufacturing procedure was standardized by using a plastic index (4.5-mm internal diameter and 5-mm height) and a custom-made dowel holder, which held the dowel head. Prepared specimens were stored in water at room temperature for 3 months and then loaded to fracture in a universal testing machine with a crosshead speed of 0.05 mm/min until failure. Bond strengths were recorded (MPa). Data were analyzed with 2-way analysis of variance (ANOVA) in a 2 x 3 factorial randomized design (alpha=.05). Afterward, core material differences were computed with 1-way ANOVA for both of the bonded and nonbonded groups. Post hoc multiple comparisons were made with the Dunnett C multiple range test. Dowel-head retention values (MPa) of the tested core materials (mean +/- SD) from the highest to the lowest were as follows: bonded amalgam core, 296.1 +/- 108; bonded composite core, 284.3 +/- 38.3; nonbonded composite core, 177.0 +/- 53.7; nonbonded amalgam core, 128.5 +/- 35.0; bonded glass-ionomer core (GIC), 128.0 +/- 24.5; nonbonded GIC, 61.8 +/- 13.3. Two-way ANOVA revealed significant differences between the core material groups and between the bonded and nonbonded groups (P <.001). The interaction between the core material and bond variables was also significant (P =.018). One-way ANOVA revealed statistically significant differences between the bonded (P <.001) and also between the nonbonded core material groups (P <.001). Post hoc multiple comparisons showed that the dowel-head retention of the GIC was significantly weaker than the post-head retention for amalgam and resin composite, whether bonded or not. Within the limitations of this study, the adhesive resin luting agent tested appeared to have a significant strengthening effect on the dowel-head retention of the core materials.

Visible CWDM system design for Multi-Gbit/s transmission over SI-POF

NASA Astrophysics Data System (ADS)

Vázquez, Carmen; Pinzón, Plinio Jesús; Pérez, Isabel

2015-01-01

In order to increase the data rates of Multi-Gbit/s links based on large core step index (SI) plastic optical fibers (POF), different modulation scenes have been proposed. Another option is to use multiple optical carriers for parallel transmission of communication channels over the same fiber. Some designs to reach data rates of 14.77 Gb/s in 50 m, with 4 channels have been developed by off line processing. In this work, designs to test the potential of real Multi- Gbit/s transmission systems using commercial products are reported. Special care in designing low insertion loss multiplexers and demultiplexers is carried out to allow for greener solutions in terms of power consumption.

Chandra Observations of MS0440.5+0204 & MS0839.9+2938: Cooling Flow Clusters in Formation?

NASA Astrophysics Data System (ADS)

McNamara, Brian

2000-09-01

We propose to observe two redshift z~0.2 clusters, MS0839.9+2938 and MS0440+0204, discovered as bright X-ray sources in the Einstein Medium Sensitivity Survey. The cluster cores are structured in the X-ray and optical bands, and they harbor large cooling flows. Their central cluster galaxies contain luminous nebular emission systems, active star formation, and strong radio sources. Using the Chandra data, we will determine whether the large discrepancies between the X-ray cooling rates and optical star formation rates can be reconciled, and we will test the hypothesis that cooling flows form as cool, dense groups accrete into massive clusters.

Pore-water extraction from unsaturated tuff by triaxial and one-dimensional compression methods, Nevada Test Site, Nevada

USGS Publications Warehouse

Mower, Timothy E.; Higgins, Jerry D.; Yang, In C.; Peters, Charles A.

1994-01-01

Study of the hydrologic system at Yucca Mountain, Nevada, requires the extraction of pore-water samples from welded and nonwelded, unsaturated tuffs. Two compression methods (triaxial compression and one-dimensional compression) were examined to develop a repeatable extraction technique and to investigate the effects of the extraction method on the original pore-fluid composition. A commercially available triaxial cell was modified to collect pore water expelled from tuff cores. The triaxial cell applied a maximum axial stress of 193 MPa and a maximum confining stress of 68 MPa. Results obtained from triaxial compression testing indicated that pore-water samples could be obtained from nonwelded tuff cores that had initial moisture contents as small as 13 percent (by weight of dry soil). Injection of nitrogen gas while the test core was held at the maximum axial stress caused expulsion of additional pore water and reduced the required initial moisture content from 13 to 11 percent. Experimental calculations, together with experience gained from testing moderately welded tuff cores, indicated that the triaxial cell used in this study could not apply adequate axial or confining stress to expel pore water from cores of densely welded tuffs. This concern led to the design, fabrication, and testing of a one-dimensional compression cell. The one-dimensional compression cell used in this study was constructed from hardened 4340-alloy and nickel-alloy steels and could apply a maximum axial stress of 552 MPa. The major components of the device include a corpus ring and sample sleeve to confine the sample, a piston and base platen to apply axial load, and drainage plates to transmit expelled water from the test core out of the cell. One-dimensional compression extracted pore water from nonwelded tuff cores that had initial moisture contents as small as 7.6 percent; pore water was expelled from densely welded tuff cores that had initial moisture contents as small as 7.7 percent. Injection of nitrogen gas at the maximum axial stress did not produce additional pore water from nonwelded tuff cores, but was critical to recovery of pore water from densely welded tuff cores. Gas injection reduced the required initial moisture content in welded tuff cores from 7.7 to 6.5 percent. Based on the mechanical ability of a pore-water extraction method to remove water from welded and nonwelded tuff cores, one-dimensional compression is a more effective extraction method than triaxial compression. However, because the effects that one-dimensional compression has on pore-water chemistry are not completely understood, additional testing will be needed to verify that this method is suitable for pore-water extraction from Yucca Mountain tuffs.

Core-Sheath Paraffin-Wax-Loaded Nanofibers by Electrospinning for Heat Storage.

PubMed

Lu, Yuan; Xiao, Xiudi; Zhan, Yongjun; Huan, Changmeng; Qi, Shuai; Cheng, Haoliang; Xu, Gang

2018-04-18

Paraffin wax (PW) is widely used for smart thermoregulation materials due to its good thermal performance. However, the leakage and low thermal conductivity of PW hinder its application in the heat storage field. Accordingly, developing effective methods to address these issues is of great importance. In this study, we explored a facile approach to obtain PW-loaded core-sheath structured flexible nanofibers films via coaxial electrospinning technique. The PW as the core layer was successfully encapsulated by the sheath-layer poly(methyl methacrylate). The diameter of the fiber core increased from 395 to 848 nm as the core solution speed rate increased from 0.1 to 0.5 mL/h. In addition, it can be seen that higher core solution speed rate could lead to higher PW encapsulation efficiency according to the transmission electron microscopy results. The core-sheath nanofiber films, moreover, possessed the highest latent heat of 58.25 J/g and solidifying enthalpy of -56.49 J/g. In addition, we found that after 200 thermal cycles, there was little change in latent heat, which demonstrated that it is beneficial for the PW-loaded core-sheath structure to overcome the leakage issue and enhance thermal stability properties for the thermoregulation film.

7 CFR 1755.903 - Fiber optic service entrance cables.

Code of Federal Regulations, 2010 CFR

2010-01-01

... group or core designs must consist of 12 fibers or less. (3) When threads or tapes are used as core...: Cable designs must meet the requirements of Part 7, Testing and Test Methods, of ICEA S-110-717... testing. (1) The tests described in this section are intended for acceptance of cable designs and major...

7 CFR 1755.903 - Fiber optic service entrance cables.

Code of Federal Regulations, 2012 CFR

2012-01-01

... group or core designs must consist of 12 fibers or less. (3) When threads or tapes are used as core...: Cable designs must meet the requirements of Part 7, Testing and Test Methods, of ICEA S-110-717... testing. (1) The tests described in this section are intended for acceptance of cable designs and major...

7 CFR 1755.903 - Fiber optic service entrance cables.

Code of Federal Regulations, 2014 CFR

2014-01-01

... group or core designs must consist of 12 fibers or less. (3) When threads or tapes are used as core...: Cable designs must meet the requirements of Part 7, Testing and Test Methods, of ICEA S-110-717... testing. (1) The tests described in this section are intended for acceptance of cable designs and major...

7 CFR 1755.903 - Fiber optic service entrance cables.

Code of Federal Regulations, 2011 CFR

2011-01-01

... group or core designs must consist of 12 fibers or less. (3) When threads or tapes are used as core...: Cable designs must meet the requirements of Part 7, Testing and Test Methods, of ICEA S-110-717... testing. (1) The tests described in this section are intended for acceptance of cable designs and major...

7 CFR 1755.903 - Fiber optic service entrance cables.

Code of Federal Regulations, 2013 CFR

2013-01-01

... group or core designs must consist of 12 fibers or less. (3) When threads or tapes are used as core...: Cable designs must meet the requirements of Part 7, Testing and Test Methods, of ICEA S-110-717... testing. (1) The tests described in this section are intended for acceptance of cable designs and major...

Test Scheduling for Core-Based SOCs Using Genetic Algorithm Based Heuristic Approach

NASA Astrophysics Data System (ADS)

Giri, Chandan; Sarkar, Soumojit; Chattopadhyay, Santanu

This paper presents a Genetic algorithm (GA) based solution to co-optimize test scheduling and wrapper design for core based SOCs. Core testing solutions are generated as a set of wrapper configurations, represented as rectangles with width equal to the number of TAM (Test Access Mechanism) channels and height equal to the corresponding testing time. A locally optimal best-fit heuristic based bin packing algorithm has been used to determine placement of rectangles minimizing the overall test times, whereas, GA has been utilized to generate the sequence of rectangles to be considered for placement. Experimental result on ITC'02 benchmark SOCs shows that the proposed method provides better solutions compared to the recent works reported in the literature.

Prokaryotic Abundance and Activity in Permafrost of the Northern Victoria Land and Upper Victoria Valley (Antarctica).

PubMed

La Ferla, Rosabruna; Azzaro, Maurizio; Michaud, Luigi; Caruso, Gabriella; Lo Giudice, Angelina; Paranhos, Rodolfo; Cabral, Anderson S; Conte, Antonella; Cosenza, Alessandro; Maimone, Giovanna; Papale, Maria; Rappazzo, Alessandro Ciro; Guglielmin, Mauro

2017-08-01

Victoria Land permafrost harbours a potentially large pool of cold-affected microorganisms whose metabolic potential still remains underestimated. Three cores (BC-1, BC-2 and BC-3) drilled at different depths in Boulder Clay (Northern Victoria Land) and one sample (DY) collected from a core in the Dry Valleys (Upper Victoria Valley) were analysed to assess the prokaryotic abundance, viability, physiological profiles and potential metabolic rates. The cores drilled at Boulder Clay were a template of different ecological conditions (different temperature regime, ice content, exchanges with atmosphere and with liquid water) in the same small basin while the Dry Valleys site was very similar to BC-2 conditions but with a complete different geological history and ground ice type. Image analysis was adopted to determine cell abundance, size and shape as well as to quantify the potential viable and respiring cells by live/dead and 5-cyano-2,3-ditolyl-tetrazolium chloride staining, respectively. Subpopulation recognition by apparent nucleic acid contents was obtained by flow cytometry. Moreover, the physiological profiles at community level by Biolog-Ecoplate™ as well as the ectoenzymatic potential rates on proteinaceous (leucine-aminopeptidase) and glucidic (ß-glucosidase) organic matter and on organic phosphates (alkaline-phosphatase) by fluorogenic substrates were tested. The adopted methodological approach gave useful information regarding viability and metabolic performances of microbial community in permafrost. The occurrence of a multifaceted prokaryotic community in the Victoria Land permafrost and a large number of potentially viable and respiring cells (in the order of 10 4 -10 5 ) were recognised. Subpopulations with a different apparent DNA content within the different samples were observed. The physiological profiles stressed various potential metabolic pathways among the samples and intense utilisation rates of polymeric carbon compounds and carbohydrates, mainly in deep samples. The measured enzymatic activity rates suggested the potential capability of the microbial community to decompose proteins and polysaccharides. The microbial community seems to be appropriate to contribute to biogeochemical cycling in this extreme environment.

Performance Prediction Toolkit

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

Chennupati, Gopinath; Santhi, Nanadakishore; Eidenbenz, Stephen

The Performance Prediction Toolkit (PPT), is a scalable co-design tool that contains the hardware and middle-ware models, which accept proxy applications as input in runtime prediction. PPT relies on Simian, a parallel discrete event simulation engine in Python or Lua, that uses the process concept, where each computing unit (host, node, core) is a Simian entity. Processes perform their task through message exchanges to remain active, sleep, wake-up, begin and end. The PPT hardware model of a compute core (such as a Haswell core) consists of a set of parameters, such as clock speed, memory hierarchy levels, their respective sizes,more » cache-lines, access times for different cache levels, average cycle counts of ALU operations, etc. These parameters are ideally read off a spec sheet or are learned using regression models learned from hardware counters (PAPI) data. The compute core model offers an API to the software model, a function called time_compute(), which takes as input a tasklist. A tasklist is an unordered set of ALU, and other CPU-type operations (in particular virtual memory loads and stores). The PPT application model mimics the loop structure of the application and replaces the computational kernels with a call to the hardware model's time_compute() function giving tasklists as input that model the compute kernel. A PPT application model thus consists of tasklists representing kernels and the high-er level loop structure that we like to think of as pseudo code. The key challenge for the hardware model's time_compute-function is to translate virtual memory accesses into actual cache hierarchy level hits and misses.PPT also contains another CPU core level hardware model, Analytical Memory Model (AMM). The AMM solves this challenge soundly, where our previous alternatives explicitly include the L1,L2,L3 hit-rates as inputs to the tasklists. Explicit hit-rates inevitably only reflect the application modeler's best guess, perhaps informed by a few small test problems using hardware counters; also, hard-coded hit-rates make the hardware model insensitive to changes in cache sizes. Alternatively, we use reuse distance distributions in the tasklists. In general, reuse profiles require the application modeler to run a very expensive trace analysis on the real code that realistically can be done at best for small examples.« less

Failure Mechanisms of Thermomechanically Loaded SnAgCu/Plastic Core Solder Ball Composite Joints in Low-Temperature Co-Fired Ceramic/Printed Wiring Board Assemblies

NASA Astrophysics Data System (ADS)

Nousiainen, O.; Putaala, J.; Kangasvieri, T.; Rautioaho, R.; Vähäkangas, J.

2007-03-01

The thermal fatigue endurance of completely lead-free 95.5Sn4Ag0.7Cu/plastic core solder ball (PCSB) composite joint structures in low-temperature Co-fired ceramic/printed wiring board (LTCC/PWB) assemblies was investigated using thermal cycling tests over the temperature ranges of -40°C 125°C and 0°C 100°C. Two separate creep/fatigue failures initiated and propagated in the joints during the tests: (1) a crack along the intermetallic compound (IMC)/solder interface on the LTCC side of the joint, which formed at the high-temperature extremes; and (2) a crack in the solder near the LTCC solder land, which formed at the low-temperature extremes. Moreover, localized recrystallization was detected at the outer edge of the joints that were tested in the harsh (-40°C 125°C) test conditions. The failure mechanism was creep/fatigue-induced mixed intergranular and transgranular cracking in the recrystallized zone, but it was dominated by transgranular thermal fatigue failure beyond the recrystallized zone. The change in the failure mechanism increased the rate of crack growth. When the lower temperature extreme was raised from -40°C to 0°C, no recrystallized zone was detected and the failure was due to intergranular cracks.

[Core muscle chains activation during core exercises determined by EMG-a systematic review].

PubMed

Rogan, Slavko; Riesen, Jan; Taeymans, Jan

2014-10-15

Good core muscles strength is essential for daily life and sports activities. However, the mechanism how core muscles may be effectively triggered by exercises is not yet precisely described in the literature. The aim of this systematic review was to evaluate the rate of activation as measured by electromyography of the ventral, lateral and dorsal core muscle chains during core (trunk) muscle exercises. A total of 16 studies were included. Exercises with a vertical starting position, such as the deadlift or squat activated significantly more core muscles than exercises in the horizontal initial position.

Aerial View: SLS Intertank Arrives at Marshall for Critical Structural Testing

NASA Image and Video Library

2018-03-08

A structural test version of the intertank for NASA's new deep-space rocket, the Space Launch System, arrives at NASA’s Marshall Space Flight Center in Huntsville, Alabama, March 4, aboard the barge Pegasus. The intertank is the second piece of structural hardware for the massive SLS core stage built at NASA's Michoud Assembly Facility in New Orleans delivered to Marshall for testing. The structural test article will undergo critical testing as engineers push, pull and bend the hardware with millions of pounds of force to ensure it can withstand the forces of launch and ascent. The test hardware is structurally identical to the flight version of the intertank that will connect the core stage's two colossal propellant tanks, serve as the upper-connection point for the two solid rocket boosters and house critical avionics and electronics. Pegasus, originally used during the Space Shuttle Program, has been redesigned and extended to accommodate the SLS rocket's massive, 212-foot-long core stage -- the backbone of the rocket. The 310-foot-long barge will ferry the flight core stage from Michoud to other NASA centers for tests and launch.

Prediction of corrosion rates of water distribution pipelines according to aggressive corrosive water in Korea.

PubMed

Chung, W S; Yu, M J; Lee, H D

2004-01-01

The drinking water network serving Korea has been used for almost 100 years. Therefore, pipelines have suffered various degrees of deterioration due to aggressive environments. The pipe breaks were caused by in-external corrosion, water hammer, surface loading, etc. In this paper, we focused on describing corrosion status in water distribution pipes in Korea and reviewing some methods to predict corrosion rates. Results indicate that corrosive water of lakes was more aggressive than river water and the winter was more aggressive compared to other seasons. The roughness growth rates of Dongbok lake showed 0.23 mm/year. The high variation of corrosion rates is controlled by the aging pipes and smaller diameter. Also the phenolphthalein test on a cementitious core of cement mortar lined ductile cast iron pipe indicated the pipes over 15 years old had lost 50-100% of their lime active cross sectional area.

Preparing to Test for Deep Space

NASA Image and Video Library

2015-07-15

A structural steel section is lifted into place atop the B-2 Test Stand at NASA’s Stennis Space Center as part of modification work to prepare for testing the core stage of NASA’s new Space Launch System. The section is part of the Main Propulsion Test Article (MPTA) framework, which will support the SLS core stage for testing. The existing framework was installed on the stand in the late 1970s to test the shuttle MPTA. However, that framework had to be repositioned and modified to accommodate the larger SLS stage. About 1 million pounds of structural steel has been added, extending the framework about 100 feet higher and providing a new look to the Stennis skyline. Stennis will test the actual flight core stage for the first uncrewed SLS mission, Exploration Mission-1.

Performance of High-frequency High-flux Magnetic Cores at Cryogenic Temperatures

NASA Technical Reports Server (NTRS)

Gerber, Scott S.; Hammoud, Ahmad; Elbuluk, Malik E.; Patterson, Richard L.

2002-01-01

Three magnetic powder cores and one ferrite core, which are commonly used in inductor and transformer design for switch mode power supplies, were selected for investigation at cryogenic temperatures. The powder cores are Molypermalloy Core (MPC), High Flux Core (HFC), and Kool Mu Core (KMC). The performance of four inductors utilizing these cores has been evaluated as a function of temperature from 20 C to -180 C. All cores were wound with the same wire type and gauge to obtain equal values of inductance at room temperature. Each inductor was evaluated in terms of its inductance, quality (Q) factor, resistance, and dynamic hysteresis characteristics (B-H loop) as a function of temperature and frequency. Both sinusoidal and square wave excitations were used in these investigations. Measured data obtained on the inductance showed that both the MPC and the HFC cores maintain a constant inductance value, whereas with the KMC and ferrite core hold a steady value in inductance with frequency but decrease as temperature is decreased. All cores exhibited dependency, with varying degrees, in their quality factor and resistance on test frequency and temperature. Except for the ferrite, all cores exhibited good stability in the investigated properties with temperature as well as frequency. Details of the experimental procedures and test results are presented and discussed in the paper.

NASA Electronic Parts and Packaging Field Programmable Gate Array Single Event Effects Test Guideline Update

NASA Technical Reports Server (NTRS)

Berg, Melanie D.; LaBel, Kenneth A.

2018-01-01

The following are updated or new subjects added to the FPGA SEE Test Guidelines manual: academic versus mission specific device evaluation, single event latch-up (SEL) test and analysis, SEE response visibility enhancement during radiation testing, mitigation evaluation (embedded and user-implemented), unreliable design and its affects to SEE Data, testing flushable architectures versus non-flushable architectures, intellectual property core (IP Core) test and evaluation (addresses embedded and user-inserted), heavy-ion energy and linear energy transfer (LET) selection, proton versus heavy-ion testing, fault injection, mean fluence to failure analysis, and mission specific system-level single event upset (SEU) response prediction. Most sections within the guidelines manual provide information regarding best practices for test structure and test system development. The scope of this manual addresses academic versus mission specific device evaluation and visibility enhancement in IP Core testing.

NASA Electronic Parts and Packaging (NEPP) Field Programmable Gate Array (FPGA) Single Event Effects (SEE) Test Guideline Update

NASA Technical Reports Server (NTRS)

Berg, Melanie D.; LaBel, Kenneth A.

2018-01-01

The following are updated or new subjects added to the FPGA SEE Test Guidelines manual: academic versus mission specific device evaluation, single event latch-up (SEL) test and analysis, SEE response visibility enhancement during radiation testing, mitigation evaluation (embedded and user-implemented), unreliable design and its affects to SEE Data, testing flushable architectures versus non-flushable architectures, intellectual property core (IP Core) test and evaluation (addresses embedded and user-inserted), heavy-ion energy and linear energy transfer (LET) selection, proton versus heavy-ion testing, fault injection, mean fluence to failure analysis, and mission specific system-level single event upset (SEU) response prediction. Most sections within the guidelines manual provide information regarding best practices for test structure and test system development. The scope of this manual addresses academic versus mission specific device evaluation and visibility enhancement in IP Core testing.

Fabrication and Testing of a Modular Micro-Pocket Fission Detector Instrumentation System for Test Nuclear Reactors

NASA Astrophysics Data System (ADS)

Reichenberger, Michael A.; Nichols, Daniel M.; Stevenson, Sarah R.; Swope, Tanner M.; Hilger, Caden W.; Roberts, Jeremy A.; Unruh, Troy C.; McGregor, Douglas S.

2018-01-01

Advancements in nuclear reactor core modeling and computational capability have encouraged further development of in-core neutron sensors. Measurement of the neutron-flux distribution within the reactor core provides a more complete understanding of the operating conditions in the reactor than typical ex-core sensors. Micro-Pocket Fission Detectors have been developed and tested previously but have been limited to single-node operation and have utilized highly specialized designs. The development of a widely deployable, multi-node Micro-Pocket Fission Detector assembly will enhance nuclear research capabilities. A modular, four-node Micro-Pocket Fission Detector array was designed, fabricated, and tested at Kansas State University. The array was constructed from materials that do not significantly perturb the neutron flux in the reactor core. All four sensor nodes were equally spaced axially in the array to span the fuel-region of the reactor core. The array was filled with neon gas, serving as an ionization medium in the small cavities of the Micro-Pocket Fission Detectors. The modular design of the instrument facilitates the testing and deployment of numerous sensor arrays. The unified design drastically improved device ruggedness and simplified construction from previous designs. Five 8-mm penetrations in the upper grid plate of the Kansas State University TRIGA Mk. II research nuclear reactor were utilized to deploy the array between fuel elements in the core. The Micro-Pocket Fission Detector array was coupled to an electronic support system which has been specially developed to support pulse-mode operation. The Micro-Pocket Fission Detector array composed of four sensors was used to monitor local neutron flux at a constant reactor power of 100 kWth at different axial locations simultaneously. The array was positioned at five different radial locations within the core to emulate the deployment of multiple arrays and develop a 2-dimensional measurement of neutron flux in the reactor core.

The 25-KVA amorphous metal-core transformer developmental test report

NASA Astrophysics Data System (ADS)

Urata, G. V.; Franchi, J. O.; Franchi, P. E.

1989-08-01

NCEL has completed a test and evaluation program for 25-kVA amorphous metal-core transformers. These transformers save energy by reducing no-load losses by 60 to 70 percent. No-load losses are estimated to cost the Navy millions annually and if all of the Navy transformers were replaced by amorphous metal-core transformers, the Navy would save millions a year. The program objective was to evaluate the electrical performance and operational reliability of the amorphous metal-core transformers compared to conventional silicon-steel transformers.

Neutron dose rate analysis on HTGR-10 reactor using Monte Carlo code

NASA Astrophysics Data System (ADS)

Suwoto; Adrial, H.; Hamzah, A.; Zuhair; Bakhri, S.; Sunaryo, G. R.

2018-02-01

The HTGR-10 reactor is cylinder-shaped core fuelled with kernel TRISO coated fuel particles in the spherical pebble with helium cooling system. The outlet helium gas coolant temperature outputted from the reactor core is designed to 700 °C. One advantage HTGR type reactor is capable of co-generation, as an addition to generating electricity, the reactor was designed to produce heat at high temperature can be used for other processes. The spherical fuel pebble contains 8335 TRISO UO2 kernel coated particles with enrichment of 10% and 17% are dispersed in a graphite matrix. The main purpose of this study was to analysis the distribution of neutron dose rates generated from HTGR-10 reactors. The calculation and analysis result of neutron dose rate in the HTGR-10 reactor core was performed using Monte Carlo MCNP5v1.6 code. The problems of double heterogeneity in kernel fuel coated particles TRISO and spherical fuel pebble in the HTGR-10 core are modelled well with MCNP5v1.6 code. The neutron flux to dose conversion factors taken from the International Commission on Radiological Protection (ICRP-74) was used to determine the dose rate that passes through the active core, reflectors, core barrel, reactor pressure vessel (RPV) and a biological shield. The calculated results of neutron dose rate with MCNP5v1.6 code using a conversion factor of ICRP-74 (2009) for radiation workers in the radial direction on the outside of the RPV (radial position = 220 cm from the center of the patio HTGR-10) provides the respective value of 9.22E-4 μSv/h and 9.58E-4 μSv/h for enrichment 10% and 17%, respectively. The calculated values of neutron dose rates are compliant with BAPETEN Chairman’s Regulation Number 4 Year 2013 on Radiation Protection and Safety in Nuclear Energy Utilization which sets the limit value for the average effective dose for radiation workers 20 mSv/year or 10μSv/h. Thus the protection and safety for radiation workers to be safe from the radiation source has been fulfilled. From the result analysis, it can be concluded that the model of calculation result of neutron dose rate for HTGR-10 core has met the required radiation safety standards.

Radiocarbon Evidence of Active Endolithic Microbial Communities in the Hyperarid Core of the Atacama Desert

PubMed Central

Wierzchos, Jacek; Davila, Alfonso F.; Slater, Gregory F.

2013-01-01

Abstract The hyperarid core of the Atacama Desert is one of the driest and most inhospitable places on Earth, where life is most commonly found in the interior of rocks (i.e., endolithic habitats). Due to the extreme dryness, microbial activity in these habitats is expected to be low; however, the rate of carbon cycling within these microbial communities remains unknown. We address this issue by characterizing the isotopic composition (13C and 14C) of phospholipid fatty acids (PLFA) and glycolipid fatty acids (GLFA) in colonized rocks from four different sites inside the hyperarid core. δ13C results suggest that autotrophy and/or quantitative conversion of organic matter to CO2 are the dominant processes occurring with the rock. Most Δ14C signatures of PLFA and GLFA were consistent with modern atmospheric CO2, indicating that endoliths are using atmospheric carbon as a primary carbon source and are also cycling carbon quickly. However, at one site the PLFA contained 14C from atmospheric nuclear weapons testing that occurred during the 1950s and 1960s, indicating a decadal rate of carbon cycling. At the driest site (Yungay), based on the relative abundance and 14C content of GLFA and PLFA, there was evidence of possible preservation. Hence, in low-moisture conditions, glycolipids may persist while phospholipids are preferentially hydrolyzed. Key Words: Endoliths—Extremophile—Carbon isotopes—Radiocarbon—Lipids. Astrobiology 13, 607–616. PMID:23848470

ATR LEU Fuel and Burnable Absorber Neutronics Performance Optimization by Fuel Meat Thickness Variation

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

G. S. Chang

2007-09-01

The Advanced Test Reactor (ATR) is a high power density and high neutron flux research reactor operating in the United States. Powered with highly enriched uranium (HEU), the ATR has a maximum thermal power rating of 250 MWth. Because of the large test volumes located in high flux areas, the ATR is an ideal candidate for assessing the feasibility of converting an HEU driven reactor to a low-enriched core. The present work investigates the necessary modifications and evaluates the subsequent operating effects of this conversion. A detailed plate-by-plate MCNP ATR 1/8th core model was developed and validated for a fuelmore » cycle burnup comparison analysis. Using the current HEU U 235 enrichment of 93.0 % as a baseline, an analysis can be performed to determine the low-enriched uranium (LEU) density and U-235 enrichment required in the fuel meat to yield an equivalent K-eff between the HEU core and the LEU core versus effective full power days (EFPD). The MCNP ATR 1/8th core model will be used to optimize the U-235 loading in the LEU core, such that the differences in K-eff and heat flux profile between the HEU and LEU core can be minimized. The depletion methodology MCWO was used to calculate K-eff versus EFPDs in this paper. The MCWO-calculated results for the LEU cases with foil (U-10Mo) types demonstrated adequate excess reactivity such that the K-eff versus EFPDs plot is similar to the reference ATR HEU case. Each HEU fuel element contains 19 fuel plates with a fuel meat thickness of 0.508 mm. In this work, the proposed LEU (U-10Mo) core conversion case with a nominal fuel meat thickness of 0.508 mm and the same U-235 enrichment (15.5 wt%) can be used to optimize the radial heat flux profile by varying the fuel plate thickness from 0.254 to 0.457 mm at the inner 4 fuel plates (1-4) and outer 4 fuel plates (16-19). In addition, a 0.7g of burnable absorber Boron-10 was added in the inner and outer plates to reduce the initial excess reactivity, and the inner/outer heat flux more effectively. The optimized LEU relative radial fission heat flux profile is bounded by the reference ATR HEU case. However, to demonstrate that the LEU core fuel cycle performance can meet the Updated Final Safety Analysis Report (UFSAR) safety requirements, additional studies will be necessary to evaluate and compare safety parameters such as void reactivity and Doppler coefficients, control components worth (outer shim control cylinders, safety rods and regulating rod), and shutdown margins between the HEU and LEU cores.« less

The rotational shear in pre-collapse cores of massive stars

NASA Astrophysics Data System (ADS)

Zilberman, Noa; Gilkis, Avishai; Soker, Noam

2018-02-01

We evolve stellar models to study the rotational profiles of the pre-explosion cores of single massive stars that are progenitors of core collapse supernovae (CCSNe), and find large rotational shear above the iron core that might play an important role in the jet feedback explosion mechanism by amplifying magnetic fields before and after collapse. Initial masses of 15 and 30 M⊙ and various values of the initial rotation velocity are considered, as well as a reduced mass-loss rate along the evolution and the effect of core-envelope coupling through magnetic fields. We find that the rotation profiles just before core collapse differ between models, but share the following properties. (1) There are narrow zones of very large rotational shear adjacent to convective zones. (2) The rotation rate of the inner core is slower than required to form a Keplerian accretion disc. (3) The outer part of the core and the envelope have non-negligible specific angular momentum compared to the last stable orbit around a black hole (BH). Our results suggest the feasibility of magnetic field amplification which might aid a jet-driven explosion leaving behind a neutron star. Alternatively, if the inner core fails in exploding the star, an accretion disc from the outer parts of the core might form and lead to a jet-driven CCSN which leaves behind a BH.

Pulse repetition rate multiplication by Talbot effect in a coaxial fiber

NASA Astrophysics Data System (ADS)

Dhingra, Nikhil; Saxena, Geetika Jain; Anand, Jyoti; Sharma, Enakshi K.

2018-03-01

We use a coaxial fiber, which is a cylindrical coupled waveguide structure consisting of two concentric cores, the inner rod and an outer ring core as a first order dispersive media to achieve temporal Talbot effect for pulse repetition rate multiplication (PRRM) in high bit rate optical fiber communication. It is observed that for an input Gaussian pulse train with pulse width, 2τ0=1ps at a repetition rate of 40 Gbps (repetition period, T=25ps), an output repetition rate of 640 Gbps can be achieved without significant distortion at a length of 40.92 m.

Fracture resistance of five pin-retained core build-up materials on teeth with and without extracoronal preparation.

PubMed

Burke, F J; Shaglouf, A G; Combe, E C; Wilson, N H

2000-01-01

Core build-ups should provide satisfactory strength and resistance to fracture both before and after crown preparation. This paper examines the resistance to fracture of core build-ups in different materials and the fracture resistance of core build-ups when these have been reduced for full crown preparation. Standardized core build-ups were made on groups of extracted molar teeth of similar size, with 10 teeth per group. Three resin-composite (prisma APH: Dentsply, Weybridge, UK; Ti-Core, Essential Dental Systems, NJ, US and Coradent, Vivadent, Liechtenstein), one cermet (Ketac-Silver, ESPE GmbH, Seefeld, Germany) and one amalgam material (Duralloy, Degussa Ltd, Cheshire, UK). These specimens were subjected to compressive force on a universal testing machine and the force at fracture noted. Standardized full crown preparations were made on a further five groups of core build-up specimens using the same materials as above. These prepared specimens were subjected to compressive force on a universal testing machine and the force to fracture noted. The results indicated that amalgam core build-ups demonstrated higher fracture resistance than the other materials examined. There was a general decrease in the fracture strength of the specimens following crown preparation, with the teeth restored with the amalgam core build-ups showing a greater percentage reduction in fracture strength than the other materials tested. Prepared core build-ups in a hybrid composite material provided the highest fracture resistance. The cermet material used provided the lowest resistance to fracture in both the core build-up and crown preparation specimens. In terms of fracture resistance, no advantage was apparent in using the two composite materials designated as being specifically appropriate for core build-ups.

Improved Thermoplastic/Iron-Particle Transformer Cores

NASA Technical Reports Server (NTRS)

Wincheski, Russell A.; Bryant, Robert G.; Namkung, Min

2004-01-01

A method of fabricating improved transformer cores from composites of thermoplastic matrices and iron-particles has been invented. Relative to commercially available laminated-iron-alloy transformer cores, the cores fabricated by this method weigh less and are less expensive. Relative to prior polymer-matrix/ iron-particle composite-material transformer cores, the cores fabricated by this method can be made mechanically stronger and more magnetically permeable. In addition, whereas some prior cores have exhibited significant eddy-current losses, the cores fabricated by this method exhibit very small eddy-current losses. The cores made by this method can be expected to be attractive for use in diverse applications, including high-signal-to-noise transformers, stepping motors, and high-frequency ignition coils. The present method is a product of an experimental study of the relationships among fabrication conditions, final densities of iron particles, and mechanical and electromagnetic properties of fabricated cores. Among the fabrication conditions investigated were molding pressures (83, 104, and 131 MPa), and molding temperatures (250, 300, and 350 C). Each block of core material was made by uniaxial-compression molding, at the applicable pressure/temperature combination, of a mixture of 2 weight percent of LaRC (or equivalent high-temperature soluble thermoplastic adhesive) with 98 weight percent of approximately spherical iron particles having diameters in the micron range. Each molded block was cut into square cross-section rods that were used as core specimens in mechanical and electromagnetic tests. Some of the core specimens were annealed at 900 C and cooled slowly before testing. For comparison, a low-carbon-steel core was also tested. The results of the tests showed that density, hardness, and rupture strength generally increased with molding pressure and temperature, though the correlation was rather weak. The weakness of the correlation was attributed to the pores in the specimens. The maximum relative permeabilities of cores made without annealing ranged from 30 to 110, while those of cores made with annealing ranged from 900 to 1,400. However, the greater permeabilities of the annealed specimens were not associated with noticeably greater densities. The major practical result of the investigation was the discovery of an optimum distribution of iron-particle sizes: It was found that eddy-current losses in the molded cores were minimized by using 100 mesh (corresponding to particles with diameters less than or equal to 100 m) iron particles. The effect of optimization of particle sizes on eddy-current losses is depicted in the figure.

Fast reactor core concepts to improve transmutation efficiency

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

Fujimura, Koji; Kawashima, Katsuyuki; Itooka, Satoshi

Fast Reactor (FR) core concepts to improve transmutation efficiency were conducted. A heterogeneous MA loaded core was designed based on the 1000MWe-ABR breakeven core. The heterogeneous MA loaded core with Zr-H loaded moderated targets had a better transmutation performance than the MA homogeneous loaded core. The annular pellet rod design was proposed as one of the possible design options for the MA target. It was shown that using annular pellet MA rods mitigates the self-shielding effect in the moderated target so as to enhance the transmutation rate.

Roles of nuclear weak rates on the evolution of degenerate cores in stars

NASA Astrophysics Data System (ADS)

Suzuki, Toshio; Tsunodaa, Naofumi; Tsunoda, Yuhsuke; Shimizu, Noritaka; Otsuka, Takaharu

2018-01-01

Electron-capture and β-decay rates in stellar environments are evaluated with the use of new shell-model Hamiltonians for sd-shell and pf-shell nuclei as well as for nuclei belonging to the island of inversion. Important role of the nuclear weak rates on the final evolution of stellar degenerate cores is presented. The weak interaction rates for sd-shell nuclei are calculated to study nuclear Urca processes in O-Ne-Mg cores of stars with 8-10 M⊙ (solar mass) and their effects on the final fate of the stars. Nucleosynthesis of iron-group elements in Type Ia supernova explosions are studied with the weak rates for pf-shell nuclei. The problem of the neutron-rich iron-group isotope over-production compared to the solar abundances is shown to be nearly solved with the use of the new rates and explosion model of slow defraglation with delayed detonation. Evaluation of the weak rates is extended to the island of inversion and the region of neutron-rich nuclei near 78Ni, where two major shells contribute to their configurations.

Tailored Core Shell Cathode Powders for Solid Oxide Fuel Cells

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

Swartz, Scott

2015-03-23

In this Phase I SBIR project, a “core-shell” composite cathode approach was evaluated for improving SOFC performance and reducing degradation of lanthanum strontium cobalt ferrite (LSCF) cathode materials, following previous successful demonstrations of infiltration approaches for achieving the same goals. The intent was to establish core-shell cathode powders that enabled high performance to be obtained with “drop-in” process capability for SOFC manufacturing (i.e., rather than adding an infiltration step to the SOFC manufacturing process). Milling, precipitation and hetero-coagulation methods were evaluated for making core-shell composite cathode powders comprised of coarse LSCF “core” particles and nanoscale “shell” particles of lanthanum strontiummore » manganite (LSM) or praseodymium strontium manganite (PSM). Precipitation and hetero-coagulation methods were successful for obtaining the targeted core-shell morphology, although perfect coverage of the LSCF core particles by the LSM and PSM particles was not obtained. Electrochemical characterization of core-shell cathode powders and conventional (baseline) cathode powders was performed via electrochemical impedance spectroscopy (EIS) half-cell measurements and single-cell SOFC testing. Reliable EIS testing methods were established, which enabled comparative area-specific resistance measurements to be obtained. A single-cell SOFC testing approach also was established that enabled cathode resistance to be separated from overall cell resistance, and for cathode degradation to be separated from overall cell degradation. The results of these EIS and SOFC tests conclusively determined that the core-shell cathode powders resulted in significant lowering of performance, compared to the baseline cathodes. Based on the results of this project, it was concluded that the core-shell cathode approach did not warrant further investigation.« less

Effect of a core conditioning intervention on tests of trunk muscular endurance in school-aged children.

PubMed

Allen, Brett A; Hannon, James C; Burns, Ryan D; Williams, Skip M

2014-07-01

Trunk and core muscular development has been advocated to increase athletic performance and for maintenance of musculoskeletal health, especially related to the prevention of low back pain (LBP). The purpose of this study was to examine the effects of a simple core conditioning routine on tests of trunk and core muscular endurance in school-aged children. Participants included 164 students (86 girls, 78 boys; mean age, 11.5 ± 2.5 years) recruited from a grade school in a metropolitan area located in the southwestern United States. Students performed an equipment-free, moderate-to-high intensity, dynamic core conditioning warm-up routine once a week for a period of 6 weeks during the start of their physical education classes. The intervention consisted of 10 different dynamic core conditioning exercises performed at a 30-second duration per exercise totaling 5 minutes per session. Pre- and post-assessments of muscular endurance consisted of 5 different trunk and core muscular endurance tests: Parallel Roman Chair Dynamic Back Extension, Prone Plank, Lateral Plank, Dynamic Curl-Up, and Static Curl-up. A generalized estimation equation was used to analyze differences in pre- and post-intervention muscular fitness assessments controlling for gender and grade level. Analysis of the data revealed significant increases in muscular fitness test performance for each of the 5 measured outcomes (p < 0.001). Because risk factors of LBP are thought to commence during childhood, results of this study suggest that it may be desirable for children and adolescents to perform moderate-to-high intensity dynamic core exercises during physical education warm-up to improve trunk and core muscular endurance.

Consent-based access to core EHR information. Collaborative approaches in Norway.

PubMed

Heimly, Vigdis; Berntsen, Kirsti E

2009-01-01

Lack of access to updated drug information is a challenge for healthcare providers in Norway. Drug charts are updated in separate EHR systems but exchange of drug information between them is lacking. In order to provide ready access to updated medication information, a project for consent-based access to a core EHR has been established. End users have developed requirements for additions to the medication modules in the EHR systems in cooperation with vendors, researchers and standardization workers. The modules are then implemented by the vendors, tested in the usability lab, and finally tested by the national testing and approval service before implementation. An ethnographic study, with focus on future users and their interaction with other actors regarding medicines and medication, has included semi-/unstructured interviews with the involved organizational units. The core EHR uses the EHR kept by the patient's regular GP as the main source of information. A server-based solution has been chosen in order to keep the core EHR accessible outside the GP's regular work hours. The core EHR is being tested, and the EHR-vendors are implementing additions to their systems in order to facilitate communication with the core EHR. All major EHR-system vendors in Norway participate in the project. The core EHR provides a generic basis that may be used as a pilot for a national patient summary. Examples of a wider use of the core EHR can be: shared individual plans to support continuity of care, summary of the patient's contacts with health providers in different organizations, and core EHR information such as important diagnoses, allergies and contact information. Extensive electronic cooperation and communication requires that all partners adjust their documentation practices to fit with other actors' needs. The implementation effects on future work practices will be followed by researchers.

Long-term reliability study and failure analysis of quantum cascade lasers

NASA Astrophysics Data System (ADS)

Xie, Feng; Nguyen, Hong-Ky; Leblanc, Herve; Hughes, Larry; Wang, Jie; Miller, Dean J.; Lascola, Kevin

2017-02-01

Here we present lifetime test results of 4 groups of quantum cascade lasers (QCL) under various aging conditions including an accelerated life test. The total accumulated life time exceeds 1.5 million device·hours, which is the largest QCL reliability study ever reported. The longest single device aging time was 46.5 thousand hours (without failure) in the room temperature test. Four failures were found in a group of 19 devices subjected to the accelerated life test with a heat-sink temperature of 60 °C and a continuous-wave current of 1 A. Visual inspection of the laser facets of failed devices revealed an astonishing phenomenon, which has never been reported before, which manifested as a dark belt of an unknown substance appearing on facets. Although initially assumed to be contamination from the environment, failure analysis revealed that the dark substance is a thermally induced oxide of InP in the buried heterostructure semiinsulating layer. When the oxidized material starts to cover the core and blocks the light emission, it begins to cause the failure of QCLs in the accelerated test. An activation energy of 1.2 eV is derived from the dependence of the failure rate on laser core temperature. With the activation energy, the mean time to failure of the quantum cascade lasers operating at a current density of 5 kA/cm2 and heat-sink temperature of 25°C is expected to be 809 thousand hours.

Assessment of nitrification potential in ground water using short term, single-well injection experiments

USGS Publications Warehouse

Smith, R.L.; Baumgartner, L.K.; Miller, D.N.; Repert, D.A.; Böhlke, J.K.

2006-01-01

Nitrification was measured within a sand and gravel aquifer on Cape Cod, MA, using a series of single-well injection tests. The aquifer contained a wastewater-derived contaminant plume, the core of which was anoxic and contained ammonium. The study was conducted near the downgradient end of the ammonium zone, which was characterized by inversely trending vertical gradients of oxygen (270 to 0 μM) and ammonium (19 to 625 μM) and appeared to be a potentially active zone for nitrification. The tests were conducted by injecting a tracer solution (ambient ground water + added constituents) into selected locations within the gradients using multilevel samplers. After injection, the tracers moved by natural ground water flow and were sampled with time from the injection port. Rates of nitrification were determined from changes in nitrate and nitrite concentration relative to bromide. Initial tests were conducted with 15N-enriched ammonium; subsequent tests examined the effect of adding ammonium, nitrite, or oxygen above background concentrations and of adding difluoromethane, a nitrification inhibitor. In situ net nitrate production exceeded net nitrite production by 3- to 6- fold and production rates of both decreased in the presence of difluoromethane. Nitrification rates were 0.02–0.28 μmol (L aquifer)−1 h−1 with in situ oxygen concentrations and up to 0.81 μmol (L aquifer)−1 h−1 with non-limiting substrate concentrations. Geochemical considerations indicate that the rates derived from single-well injection tests yielded overestimates of in situ rates, possibly because the injections promoted small-scale mixing within a transport-limited reaction zone. Nonetheless, these tests were useful for characterizing ground water nitrification in situ and for comparing potential rates of activity when the tracer cloud included non-limiting ammonium and oxygen concentrations.

Use of thermal imagery for estimation of core body temperature during precooling, exertion, and recovery in wildland firefighter protective clothing.

PubMed

Bourlai, Thirimachos; Pryor, Riana R; Suyama, Joe; Reis, Steven E; Hostler, David

2012-01-01

Monitoring core body temperature to identify heat stress in first responders and in individuals participating in mass gatherings (e.g., marathons) is difficult. This study utilized high-sensitivity thermal imaging technology to predict the core temperature of human subjects at a distance while performing simulated field operations wearing thermal protective garments. Six male subjects participating in a study of precooling prior to exertion in wildland firefighter thermal protective clothing had thermal images of the face captured with a high-resolution thermal imaging camera concomitant with measures of core and skin temperature before, during, and after treadmill exercise in a heated room. Correlations and measures of agreement between core temperature and thermal imaging-based temperature were performed. The subjects walked an average (± standard deviation) of 42.6 (±5.9) minutes and a distance of 4.2 (±0.6) km on the treadmill. Mean heart rate at the end of exercise was 152 (±33) bpm and core body temperature at the end of exercise was 38.3°C (±0.7°C). A visual relationship and a strong correlation between core temperature and thermal imaging of the face were identified in all subjects, with the closest relationship and best agreement occurring during exercise. The Bland-Altman test of agreement during exercise revealed the majority of measurement pairs to be within two standard deviations of the measured temperature. High-resolution thermal imaging in the middle-wave infrared spectrum (3-5 μm) can be used to accurately estimate core body temperature during exertion in a hot room while participants are wearing wildland firefighting garments. Although this technology is promising, it must be refined. Using alternative measurement sites such as the skin over the carotid artery, using multiple measurement sites, or adding pulse detection may improve the estimation of body temperature by thermal imagery.

Modified Y-TZP Core Design Improves All-ceramic Crown Reliability

PubMed Central

Silva, N.R.F.A.; Bonfante, E.A.; Rafferty, B.T.; Zavanelli, R.A.; Rekow, E.D.; Thompson, V.P.; Coelho, P.G.

2011-01-01

This study tested the hypothesis that all-ceramic core-veneer system crown reliability is improved by modification of the core design. We modeled a tooth preparation by reducing the height of proximal walls by 1.5 mm and the occlusal surface by 2.0 mm. The CAD-based tooth preparation was replicated and positioned in a dental articulator for core and veneer fabrication. Standard (0.5 mm uniform thickness) and modified (2.5 mm height lingual and proximal cervical areas) core designs were produced, followed by the application of veneer porcelain for a total thickness of 1.5 mm. The crowns were cemented to 30-day-aged composite dies and were either single-load-to-failure or step-stress-accelerated fatigue-tested. Use of level probability plots showed significantly higher reliability for the modified core design group. The fatigue fracture modes were veneer chipping not exposing the core for the standard group, and exposing the veneer core interface for the modified group. PMID:21057036

Physiological responses during graded treadmill exercise in chemical-resistant personal protective equipment.

PubMed

Northington, William E; Suyama, Joe; Goss, Fredric L; Randall, Colby; Gallagher, Michael; Hostler, David

2007-01-01

As the likelihood of terrorist acts increases, prehospital personnel have been forced to train in the proper use of chemical-resistant personal protective equipment (PPE). This protective ensemble has been reported to be physiologically taxing for the wearer, imposing an additional thermal load resulting in hypohydration, hyperthermia, and reduced work time. Victim extrication, the rescue-the-rescuer role of the rapid intervention team and rapid self-extrication, typically requires high-intensity work that can be maintained only for short time intervals. The additional physiological burden imparted by the level C PPE during high-intensity work is unknown. We hypothesized that the added thermal burden resulting from work in PPE would shorten work time and result in a higher core temperature during incremental treadmill exercise. In this prospective, crossover, laboratory study, EMS providers (n = 8, 5 male) completed a Bruce treadmill test on two occasions: once in a chemical-resistant coverall and air-purifying respirator (PPE) and once in shorts and t-shirt (CON). Oxygen consumption, vital signs, core and skin temperature, and perceptual measures of exertion, thermal sensation, and comfort were monitored throughout the test. Subjects achieved maximal oxygen consumption and more than 90% of age-predicted maximum heart rate in both conditions. Heart rate, skin temperature, and measures of perceived exertion, comfort, and thermal sensation increased during the treadmill exercise but did not differ between the PPE and CON conditions. Core temperature increased in both the CON and PPE conditions (0.8 +/- 0.5 vs. 0.7 +/- 0.3, p = 0.40). High-intensity work in level C PPE is primarily limited by cardiovascular capacity. The thermal burden associated with this short bout of work in PPE (approximately 10 minutes) is not different than high-intensity work in short pants and cotton t-shirt. Consideration should be given to cardiorespiratory fitness when assigning providers to work in chemical-resistant PPE, especially on tasks that require high-intensity work.

When the Earth's Inner Core Shuffles

NASA Astrophysics Data System (ADS)

Tkalcic, H.; Young, M. K.; Bodin, T.; Ngo, S.; Sambridge, M.

2011-12-01

Shuffling is a tribal dance recently adapted by teenagers as a street dance. In one of the most popular moves, the so-called "Running Man", a stomp forward on one foot, shifted without being lifted from the ground, is followed by a change of position backwards on the same foot. Here, we present strong observational evidence from a newly observed collection of earthquake doublets that the Earth's inner core "shuffles" exhibiting both prograde and retrograde rotation in the reference frame of the mantle. This discovery is significant on several levels. First, the observed pattern consists of intermittent intervals of quasi-locked and differentially rotating inner core with respect to the Earth's mantle. This means that the angular alignment of the inner core and mantle oscillates in time over the past five decades. Jolting temporal changes are revealed, indicating that during the excursions from the quasi-locked state, the Earth's inner core can rotate both faster and slower than the rest of the planet, thus exhibiting both eastward and westward rotation. According to our results, a short time interval (on the order of one to two years) is needed for the inner core to accelerate to a differential rotation rate of several degrees per year, and typically a slightly longer time is needed to decelerate down to a negligibly small differential rotation rate. These time scales are in agreement with experimental spin-up times obtained when the magnetic torque alone is used to accelerate the inner core. Second, when we integrate the rotation rate over different time intervals, it is possible to explain discrepancies between the body wave and normal modes results for the rate of the inner core differential rotation found by previous authors. We show that the integrated shift in angular alignment and average rotation rates (previously determined to be constant) in normal mode studies are much smaller that those for the body waves. The repeating earthquakes from the South Atlantic generate elastic waves that traverse the Earth's mantle and core, and are recorded by the seismographs located in the northern hemisphere. The waveform doublets produced by repeating earthquakes present a reliable probe, which can reveal temporal changes exhibited by the inner core due to the fact that the mantle effects are minimized. We observe new waveform-doublets at the College station, Alaska, and analyse all existing doublets recorded at that station using state of the art mathematical methods. The complex temporal pattern of differences in travel times between the first and the second event of a doublet is impossible to explain with a simple linear-fit approach. An ensemble approach utilizing transdimensional and hierarchical Bayesian analysis proves to be a powerful approach in this case, relaxing the choices on model parameterization and revealing hitherto unseen complex dynamics of the Earth's inner core.

Effects of core strength training using stable versus unstable surfaces on physical fitness in adolescents: a randomized controlled trial.

PubMed

Granacher, Urs; Schellbach, Jörg; Klein, Katja; Prieske, Olaf; Baeyens, Jean-Pierre; Muehlbauer, Thomas

2014-01-01

It has been demonstrated that core strength training is an effective means to enhance trunk muscle strength (TMS) and proxies of physical fitness in youth. Of note, cross-sectional studies revealed that the inclusion of unstable elements in core strengthening exercises produced increases in trunk muscle activity and thus provide potential extra training stimuli for performance enhancement. Thus, utilizing unstable surfaces during core strength training may even produce larger performance gains. However, the effects of core strength training using unstable surfaces are unresolved in youth. This randomized controlled study specifically investigated the effects of core strength training performed on stable surfaces (CSTS) compared to unstable surfaces (CSTU) on physical fitness in school-aged children. Twenty-seven (14 girls, 13 boys) healthy subjects (mean age: 14 ± 1 years, age range: 13-15 years) were randomly assigned to a CSTS (n = 13) or a CSTU (n = 14) group. Both training programs lasted 6 weeks (2 sessions/week) and included frontal, dorsal, and lateral core exercises. During CSTU, these exercises were conducted on unstable surfaces (e.g., TOGU© DYNAIR CUSSIONS, THERA-BAND© STABILITY TRAINER). Significant main effects of Time (pre vs. post) were observed for the TMS tests (8-22%, f = 0.47-0.76), the jumping sideways test (4-5%, f = 1.07), and the Y balance test (2-3%, f = 0.46-0.49). Trends towards significance were found for the standing long jump test (1-3%, f = 0.39) and the stand-and-reach test (0-2%, f = 0.39). We could not detect any significant main effects of Group. Significant Time x Group interactions were detected for the stand-and-reach test in favour of the CSTU group (2%, f = 0.54). Core strength training resulted in significant increases in proxies of physical fitness in adolescents. However, CSTU as compared to CSTS had only limited additional effects (i.e., stand-and-reach test). Consequently, if the goal of training is to enhance physical fitness, then CSTU has limited advantages over CSTS. ClinicalTrials.gov Identifier: NCT02290457 Registered 13 November 2014.

Acrylonitrile Quenching of Trp Phosphorescence in Proteins: A Probe of the Internal Flexibility of the Globular Fold

PubMed Central

Strambini, Giovanni B.; Gonnelli, Margherita

2010-01-01

Quenching of Trp phosphorescence in proteins by diffusion of solutes of various molecular sizes unveils the frequency-amplitude of structural fluctuations. To cover the sizes gap between O2 and acrylamide, we examined the potential of acrylonitrile to probe conformational flexibility of proteins. The distance dependence of the through-space acrylonitrile quenching rate was determined in a glass at 77 K, with the indole analog 2-(3-indoyl) ethyl phenyl ketone. Intensity and decay kinetics data were fitted to a rate, k(r) = k0 exp[−(r − r0)/re], with an attenuation length re = 0.03 nm and a contact rate k0 = 3.6 × 1010 s−1. At ambient temperature, the bimolecular quenching rate constant (kq) was determined for a series of proteins, appositely selected to test the importance of factors such as the degree of Trp burial and structural rigidity. Relative to kq = 1.9 × 109 M−1s−1 for free Trp in water, in proteins kq ranged from 6.5 × 106 M−1s−1 for superficial sites to 1.3 × 102 M−1s−1 for deep cores. The short-range nature of the interaction and the direct correlation between kq and structural flexibility attest that in the microsecond-second timescale of phosphorescence acrylonitrile readily penetrates even compact protein cores and exhibits significant sensitivity to variations in dynamical structure of the globular fold. PMID:20682273

Rocket Based Combined Cycle Exchange Inlet Performance Estimation at Supersonic Speeds

NASA Astrophysics Data System (ADS)

Murzionak, Aliaksandr

A method to estimate the performance of an exchange inlet for a Rocket Based Combined Cycle engine is developed. This method is to be used for exchange inlet geometry optimization and as such should be able to predict properties that can be used in the design process within a reasonable amount of time to allow multiple configurations to be evaluated. The method is based on a curve fit of the shocks developed around the major components of the inlet using solutions for shocks around sharp cones and 2D estimations of the shocks around wedges with blunt leading edges. The total pressure drop across the estimated shocks as well as the mass flow rate through the exchange inlet are calculated. The estimations for a selected range of free-stream Mach numbers between 1.1 and 7 are compared against numerical finite volume method simulations which were performed using available commercial software (Ansys-CFX). The total pressure difference between the two methods is within 10% for the tested Mach numbers of 5 and below, while for the Mach 7 test case the difference is 30%. The mass flow rate on average differs by less than 5% for all tested cases with the maximum difference not exceeding 10%. The estimation method takes less than 3 seconds on 3.0 GHz single core processor to complete the calculations for a single flight condition as oppose to over 5 days on 8 cores at 2.4 GHz system while using 3D finite volume method simulation with 1.5 million elements mesh. This makes the estimation method suitable for the use with exchange inlet geometry optimization algorithm.

Effect of interactions between multiple interfaces on the rheological characteristics of double emulsions

NASA Astrophysics Data System (ADS)

Choi, Se Bin; Park, Jae Yong; Moon, Ji Young; Lee, Joon Sang

2018-06-01

In this study, we analyzed the rheological characteristics of double emulsions by using a three-dimensional lattice Boltzmann model. Numerical simulations indicate that interactions between multiple interfaces play a vital role in determining the shear stress on interfaces and affect deformations, which influence the relative viscosity of double emulsions. The large shear stress induced by droplets in contact increases the relative viscosity for high volume fractions. The double emulsions also show shear-thinning behavior, which corresponds with the Carreau model. The interfacial interference between the core and the deforming shell cause the relative viscosity to increase with increasing core-droplet radius. Finally, we investigated the dependence of the double-emulsion viscosity on the core-droplet viscosity. At high shear rates, the relative viscosity increases with increasing core-droplet viscosity. However, the trend is opposite at low shear rates, which results from the high inward flow (Marangoni flow) at low core-droplet viscosity.

Improving tree age estimates derived from increment cores: a case study of red pine

Treesearch

Shawn Fraver; John B. Bradford; Brian J. Palik

2011-01-01

Accurate tree ages are critical to a range of forestry and ecological studies. However, ring counts from increment cores, if not corrected for the years between the root collar and coring height, can produce sizeable age errors. The magnitude of errors is influenced by both the height at which the core is extracted and the growth rate. We destructively sampled saplings...

Isolating active ingredients in a parent-mediated social communication intervention for toddlers with autism spectrum disorder.

PubMed

Gulsrud, Amanda C; Hellemann, Gerhard; Shire, Stephanie; Kasari, Connie

2016-05-01

Behavioral interventions are commonplace in the treatment of autism spectrum disorders, yet relatively little is known about how and why these interventions work. This study tests the relationship between isolated core components of a packaged social communication intervention and the primary outcome, joint engagement, to better understand how the intervention is affecting change in individuals. A total of 86 toddlers and their parents were enrolled in the study and randomized to one of two treatments, the joint attention, symbolic play, engagement, and regulation (JASPER) parent-mediated intervention or a psychoeducational intervention. Measures regarding the parent's use of intervention strategies were collected before and after the 10-week intervention. Additional measures of child and parent joint engagement were also collected. A significant effect of treatment was found for all four of the core strategies of the intervention, favoring a larger increase in the JASPER condition. A hierarchical linear regression revealed several individual predictors of joint engagement, including parent-rated buy-in, interventionist-rated parent involvement, and parental use of strategies. To complement the hierarchical analysis, we also tested the potential mediating effect the strategies may have on the relationship between treatment and joint engagement. Results showed that the strategy of mirrored pacing mediated the relationship between treatment and joint engagement in the positive direction. These results strongly suggest that the mirrored pacing strategy is an active ingredient of the JASPER treatment. © 2015 Association for Child and Adolescent Mental Health.

Evaluation of Contemporary Holmium Laser Fibers for Performance Characteristics.

PubMed

Lusch, Achim; Heidari, Emon; Okhunov, Zhamshid; Osann, Kathryn; Landman, Jaime

2016-05-01

Several holmium:YAG laser fibers for urologic applications are currently commercially available. We compared contemporary holmium laser fibers with different core sizes for performance characteristics, including energy transmission, fiber failure, fiber flexibility, and core diameter. Single-use fibers from Cook, Boston Scientific, and Storz were tested in small (200 and 272/273 μm), medium (365 μm), and large (550 and 940/1000 μm) core sizes. Fibers were tested in straight and deflected configurations. All fibers were evaluated for flexibility, true fiber diameter, energy transmission, and fiber failure. For energy transmission, fibers were tested at a pulse energy of 1 J and a frequency of 10 Hz for 30 seconds. All tests were performed on a 30 W holmium laser. For the small core fibers, Storz, Cook OptiLite, and Smart Sync had the smallest core diameter (p < 0.005). In the large core group, Cook OptiLite and Boston Scientific AccuMax showed the smallest diameter. Among the small core fibers, Storz and Cook Smart Sync showed a significant higher deflection, whereas in the 550 μm group, Boston Scientific AccuMax and Cook Smart Sync were the most flexible fibers. In the large and medium core groups, Boston Scientific AccuMax showed superior energy transmission (p = 0.007 and p = 0.001, respectively), whereas in the small core group, there was no significant difference between the fibers, except for 272/3 μm (Storz was inferior compared with the competitors [p < 0.0005]). For fiber failure, Storz, Cook OptiLite, and BS AccuTrac completed all testing without failing (200 μm, bending radius <0.5 cm). In the 365 μm group, Cook OptiLite showed superior results, whereas in the large core group, Boston Scientific AccuMax was superior. Performance characteristics differ significantly between different laser fiber diameters and manufacturers, and fiber choice should depend on specific surgical requirements. There is a trend for less fiber fracture at long pulse, high energy, and low frequency, but this finding will require further investigation.

Computer Simulation To Assess The Feasibility Of Coring Magma

NASA Astrophysics Data System (ADS)

Su, J.; Eichelberger, J. C.

2017-12-01

Lava lakes on Kilauea Volcano, Hawaii have been successfully cored many times, often with nearly complete recovery and at temperatures exceeding 1100oC. Water exiting nozzles on the diamond core bit face quenches melt to glass just ahead of the advancing bit. The bit readily cuts a clean annulus and the core, fully quenched lava, passes smoothly into the core barrel. The core remains intact after recovery, even when there are comparable amounts of glass and crystals with different coefficients of thermal expansion. The unique resulting data reveal the rate and sequence of crystal growth in cooling basaltic lava and the continuous liquid line of descent as a function of temperature from basalt to rhyolite. Now that magma bodies, rather than lava pooled at the surface, have been penetrated by geothermal drilling, the question arises as to whether similar coring could be conducted at depth, providing fundamentally new insights into behavior of magma. This situation is considerably more complex because the coring would be conducted at depths exceeding 2 km and drilling fluid pressures of 20 MPa or more. Criteria that must be satisfied include: 1) melt is quenched ahead of the bit and the core itself must be quenched before it enters the barrel; 2) circulating drilling fluid must keep the temperature of the coring assembling cooled to within operational limits; 3) the drilling fluid column must nowhere exceed the local boiling point. A fluid flow simulation was conducted to estimate the process parameters necessary to maintain workable temperatures during the coring operation. SolidWorks Flow Simulation was used to estimate the effect of process parameters on the temperature distribution of the magma immediately surrounding the borehole and of drilling fluid within the bottom-hole assembly (BHA). A solid model of the BHA was created in SolidWorks to capture the flow behavior around the BHA components. Process parameters used in the model include the fluid properties and temperature of magma, coolant flow rate, rotation speed, and rate of penetration (ROP). The modeling results indicate that there are combinations of process parameters that will provide sufficient cooling to enable the desired coring process in magma.

The earth's C21 and S21 gravity coefficients and the rotation of the core

NASA Technical Reports Server (NTRS)

Wahr, John M.

1987-01-01

Observational results for the earth's C21 and S21 gravity coefficients can be used to constrain the mean equatorial rotation of the core with respect to the mantle. Current satellite gravity solutions suggest the equatorial rotation rate is no larger than 1 x 10 to the -7th times the earth's diurnal spin rate, a limit more than one order of magnitude smaller than the polar rotation rate inferred from the westward drift of the earth's magnetic field. The next generation gravity solutions should improve this constraint by more than one order of magnitude. Implications for the fluid pressure at the core-mantle boundary and for the shape of that boundary are discussed.

Publications - GMC 146 | Alaska Division of Geological & Geophysical

Science.gov Websites

concentrates from the following 2 NPRA core tuff samples: U.S. Navy Umiat Test #1 (510.5 feet); Umiat Test #11 geochronology studies on biotite concentrates from the following 2 NPRA core tuff samples: U.S. Navy Umiat Test #1 (510.5 feet); Umiat Test #11 (488 feet): Alaska Division of Geological & Geophysical Surveys

Preliminary data for northern Great Plains test well 1, quarter NE quarter Sec. 11, T.55N., R.77W., Sheridan County, Wyoming

USGS Publications Warehouse

Lobmeyer, D.H.; Anna, L.O.; Busby, J.F.

1982-01-01

This report documents the preliminary data obtained from Northern Great Plains test well 1 and describes the preliminary results and future testing plans. The intended audience includes hydrologists, local water users, drilling contractors, and water managers. The test well was drilled as part of the study to determine the water resource potential of the regional aquifer system in the Northern Great Plains, an area of about 250,000 sq mi. The well is 4,485 ft deep; nine cores were drilled totaling 182 ft; 157.42 ft of core were recovered. Sidewall cores were obtained from 24 horizons. Gamma and density scans of the cores were made, and selected parts were tested for density, porosity, and vertical and horizontal permeability. Eight zones were perforated and tested using conventional drill-stem tests and swabbing. Water samples were obtained from seven zones. No major potential sources of groundwater were penetrated by the test well. Estimated yields from selected zones range from about 240 gal/min with 400 ft of drawdown to about 5 gal/min flow at the surface. Dissolved-solids concentrations ranged from about 1,800 to 3,000 mg/l. (USGS)

James Webb Space Telescope Core 2 Test - Cryogenic Thermal Balance Test of the Observatorys Core Area Thermal Control Hardware

NASA Technical Reports Server (NTRS)

Cleveland, Paul; Parrish, Keith; Thomson, Shaun; Marsh, James; Comber, Brian

2016-01-01

The James Webb Space Telescope (JWST), successor to the Hubble Space Telescope, will be the largest astronomical telescope ever sent into space. To observe the very first light of the early universe, JWST requires a large deployed 6.5-meter primary mirror cryogenically cooled to less than 50 Kelvin. Three scientific instruments are further cooled via a large radiator system to less than 40 Kelvin. A fourth scientific instrument is cooled to less than 7 Kelvin using a combination pulse-tube Joule-Thomson mechanical cooler. Passive cryogenic cooling enables the large scale of the telescope which must be highly folded for launch on an Ariane 5 launch vehicle and deployed once on orbit during its journey to the second Earth-Sun Lagrange point. Passive cooling of the observatory is enabled by the deployment of a large tennis court sized five layer Sunshield combined with the use of a network of high efficiency radiators. A high purity aluminum heat strap system connects the three instrument's detector systems to the radiator systems to dissipate less than a single watt of parasitic and instrument dissipated heat. JWST's large scale features, while enabling passive cooling, also prevent the typical flight configuration fully-deployed thermal balance test that is the keystone of most space missions' thermal verification plans. This paper describes the JWST Core 2 Test, which is a cryogenic thermal balance test of a full size, high fidelity engineering model of the Observatory's 'Core' area thermal control hardware. The 'Core' area is the key mechanical and cryogenic interface area between all Observatory elements. The 'Core' area thermal control hardware allows for temperature transition of 300K to approximately 50 K by attenuating heat from the room temperature IEC (instrument electronics) and the Spacecraft Bus. Since the flight hardware is not available for test, the Core 2 test uses high fidelity and flight-like reproductions.

Hypervelocity Impact Evaluation of Metal Foam Core Sandwich Structures

NASA Technical Reports Server (NTRS)

Yasensky, John; Christiansen, Eric L.

2007-01-01

A series of hypervelocity impact (HVI) tests were conducted by the NASA Johnson Space Center (JSC) Hypervelocity Impact Technology Facility (HITF) [1], building 267 (Houston, Texas) between January 2003 and December 2005 to test the HVI performance of metal foams, as compared to the metal honeycomb panels currently in service. The HITF testing was conducted at the NASA JSC White Sands Testing Facility (WSTF) at Las Cruces, New Mexico. Eric L. Christiansen, Ph.D., and NASA Lead for Micro-Meteoroid Orbital Debris (MMOD) Protection requested these hypervelocity impact tests as part of shielding research conducted for the JSC Center Director Discretionary Fund (CDDF) project. The structure tested is a metal foam sandwich structure; a metal foam core between two metal facesheets. Aluminum and Titanium metals were tested for foam sandwich and honeycomb sandwich structures. Aluminum honeycomb core material is currently used in Orbiter Vehicle (OV) radiator panels and in other places in space structures. It has many desirable characteristics and performs well by many measures, especially when normalized by density. Aluminum honeycomb does not perform well in Hypervelocity Impact (HVI) Testing. This is a concern, as honeycomb panels are often exposed to space environments, and take on the role of Micrometeoroid / Orbital Debris (MMOD) shielding. Therefore, information on possible replacement core materials which perform adequately in all necessary functions of the material would be useful. In this report, HVI data is gathered for these two core materials in certain configurations and compared to gain understanding of the metal foam HVI performance.

Acetate concentrations and oxidation in salt marsh sediments

NASA Technical Reports Server (NTRS)

1992-01-01

Acetate concentrations and rates of acetate oxidation and sulfate reduction were measured in S. alterniflora sediments in New Hampshire and Massachusetts. Pore water extracted from cores by squeezing or centrifugation contained in greater than 0.1 mM acetate and, in some instances, greater than 1.0 mM. Pore water sampled nondestructively contained much less acetate, often less than 0.01 mM. Acetate was associated with roots, and concentrations varied with changes in plant physiology. Acetate turnover was very low whether whole core or slurry incubations were used. Radiotracers injected directly into soils yielded rates of sulfate reduction and acetate oxidation not significantly different from core incubation techniques. Regardless of incubation method, acetate oxidation did not account for a substantial percentage of sulfate reduction. These results differ markedly from data for unvegetated coastal sediments where acetate levels are low, oxidation rate constants are high, and acetate oxication rates greatly exceed rates of sulfate reduction. The discrepancy between rates of acetate oxidation and sulfate reduction in these marsh soils may be due either to the utilization of substrates other than acetate by sulfate reducers or artifacts associated with measurements of organic utilization by rhizosphere bacteria. Care must be taken when interpreting data from salt marsh sediments since the release of material from roots during coring may affect the concentrations of certain compounds as well as influencing results obtained when sediment incubations are employed.

Simulation of two-dimensional adjustable liquid gradient refractive index (L-GRIN) microlens

NASA Astrophysics Data System (ADS)

Le, Zichun; Wu, Xiang; Sun, Yunli; Du, Ying

2017-07-01

In this paper, a two-dimensional liquid gradient refractive index (L-GRIN) microlens is designed which can be used in adjusting focusing direction and focal spot of light beam. Finite element method (FEM) is used to simulate the convection diffusion process happening in core inlet flow and cladding inlet flow. And the ray tracing method shows us the light beam focusing effect including the extrapolation of focal length and output beam spot size. When the flow rates of the core and cladding fluids are held the same between the internal and external, left and right, and upper and lower inlets, the focal length varied from 313 μm to 53.3 μm while the flow rate of liquids ranges from 500 pL/s to 10,000 pL/s. While the core flow rate is bigger than the cladding inlet flow rate, the light beam will focus on a light spot with a tunable size. By adjusting the ratio of cladding inlet flow rate including Qright/Qleft and Qup/Qdown, we get the adjustable two-dimensional focus direction rather than the one-dimensional focusing. In summary, by adjusting the flow rate of core inlet and cladding inlet, the focal length, output beam spot and focusing direction of the input light beam can be manipulated. We suppose this kind of flexible microlens can be used in integrated optics and lab-on-a-chip system.

A Pilot RCT of an Internet Intervention to Reduce the Risk of Alcohol-Exposed Pregnancy.

PubMed

Ingersoll, Karen; Frederick, Christina; MacDonnell, Kirsten; Ritterband, Lee; Lord, Holly; Jones, Brogan; Truwit, Lauren

2018-06-01

Preventing alcohol-exposed pregnancies (AEPs) could reduce the incidence of fetal alcohol spectrum disorders. Previous face-to-face interventions significantly reduced risk for AEP, but a scalable intervention is needed to reach more women at risk. This study compared a 6 Core automated, interactive, and tailored Internet intervention, the Contraception and Alcohol Risk Reduction Internet Intervention (CARRII), to a static patient education (PE) website for its effect on AEP risk. Participants were recruited online to a pilot randomized clinical trial (RCT) with baseline, 9 weeks posttreatment, and 6-month (6-M) follow-up assessments. Seventy-one women completed online questionnaires and telephone interviews and were randomized to CARRII (n = 36) or PE (n = 35). Primary outcomes were rates of risky drinking, unprotected sex episodes, and AEP risk, collected from online prospective diaries. CARRII participants showed significant reductions in rate of unprotected sex from pretreatment (88.9%) to posttreatment (70.6%) (p < 0.04) and to 6-M follow-up (51.5%) (p = 0.001); rate of risky drinking from pretreatment (75.0%) to posttreatment (50.0%) (p < 0.02), but insignificant change from pretreatment to 6-M follow-up (57.6%) (p < 0.09); and rate of AEP risk from pretreatment (66.7%) to posttreatment (32.4%) (p = 0.001) and to 6-M follow-up (30.3%) (p = 0.005). PE participants demonstrated no significant changes on all 3 variables across all time points. Intent-to-treat group-by-time tests were not significant, but power was limited by missing diaries. Over 72% of CARRII participants completed all 6 Cores. Exploratory analyses suggest that higher program utilization is related to change. These data show that CARRII was acceptable, feasible, promising to reduce AEP risk, and merits further testing in a fully powered RCT. Copyright © 2018 by the Research Society on Alcoholism.

Sediment Relative Paleointensity Record With Slow-sedimentation Rates: Implication For a Chronological Tool In The Slow-sedimentation Sequence

NASA Astrophysics Data System (ADS)

Kanamatsu, T.

2006-12-01

Usefulness of paleointensity records with high-sedimentation rates in stratigraphic correlation have been proved (e.g. Stoner et al., 1998, Laj et al., 2000, Stoner et al., 2000), because the sediment geomagnetic paleointensity data makes possible the fine time correlation between cores on the older sediment than the range of AMS 14C. As father application of the sediment paleointensity for chronological tool, we examined the paleointensity record of much slower sedimentation rate. The paleointensity record of the slower sedimentation sequence is supposed to show the convoluted record by the filtering effect of the post- depositional remanent magnetization, then a unique and different pattern depending on the sedimentation rate (e.g. Guyodo and Channell, 2002). We studied the record of the cores obtained from the West Philippine Sea Basin (Water depth ca. 5000 to 6000 m). The analyses of paleomagnetic direction proved that the cores contain Jaramillo and Olduvai Events. The sedimentation rates of cores estimated from magnetostratigraphy are less than 1cm/kyr (0.6-0.4 cm/kyr). Proxy of paleointensity (NRM20mT/ARM20mT) applied to cores reveals the variations in the records are dominate in c.a. 100 ky cycle. Comparing to other published paleointensity record, it is clear that the record includes ca.100-ky cycle in spite of slower sedimentation rates, although other high frequency records were not identified. It is suggests that geomagnetic events of a few to several kys are recordable in the sediment. The paleointensity in the slow-sedimentation record is still useful for the age control utilizing the lower frequency signal, especially for investigating of less age information sequence such as the deep sea sediment below CCD, but not for fine correlation by high frequency data.