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Sample records for liss core study

  1. The lisse effect revisited

    USGS Publications Warehouse

    Weeks, E.P.

    2002-01-01

    The Lisse effect is a rarely noted phenomenon occurring when infiltration caused by intense rain seals the surface soil layer to airflow, trapping air in the unsaturated zone. Compression of air by the advancing front results in a pressure increase that produces a water-level rise in an observation well screened below the water table that is several times as large as the distance penetrated by the wetting front. The effect is triggered by intense rains and results in a very rapid water-level rise, followed by a recession lasting a few days. The Lisse effect was first noted and explained by Thal Larsen in 1932 from water-level observations obtained in a shallow well in the village of Lisse, Holland. The original explanation does not account for the increased air pressure pushing up on the bottom of the wetting front. Analysis of the effect of this upward pressure indicates that a negative pressure head at the base of the wetting front, ??f, analogous to that postulated by Green and Ampt (1911) to explain initially rapid infiltration rates into unsaturated soils, is involved in producing the Lisse effect. Analysis of recorded observations of the Lisse effect by Larsen and others indicates that the water-level rise, which typically ranges from 0.10 to 0.55 m, should be only slightly larger than |??f| and that the depth of penetration of the wetting front is no more than several millimeters.

  2. Rain-induced subsurface airflow and Lisse effect

    USGS Publications Warehouse

    Guo, H.; Jiao, J.J.; Weeks, E.P.

    2008-01-01

    Water-level increase after rainfall is usually indicative of rainfall recharge to groundwater. This, however, may not be true if the Lisse effect occurs. This effect represents the water-level increase in a well driven by airflow induced by an advancing wetting front during highly intensive rains. The rainwater, which may behave like a low-permeability lid, seals the ground surface so that the air pressure beneath the wetting front is increased because of air compression due to downward movement of the wetting front. A rapid and substantial rise of the water level in the well screened below water table, which bears no relationship to groundwater recharge, can be induced when various factors such as soil properties and the rain-runoff condition combine favorably. A transient, three-dimensional and variably saturated flow model was employed to study the air and groundwater flows in the soil under rain conditions. The objectives of this paper are two-fold: to evaluate the reliability of the theory of the Lisse effect presented by Weeks to predict its magnitude in modeled situations that mimic the physical complexity of real aquifers, and to conduct parametric studies on the sensitivity of the water-level rise in the well to soil properties and the rain event. The simulation results reveal that the magnitude of the Lisse effect increases with the ponding depth. Soil permeability plays a key role in generating the Lisse effect. The water-level rise in the well is delayed relative to the air-pressure rise in the unsaturated zone when the soil permeability is low, and the maximum water-level rise is less than the maximum air pressure induced by rain infiltration. The simulation also explores the sensitivity of the Lisse effect to the van Genuchten parameters and the water table depth. Copyright 2008 by the American Geophysical Union.

  3. A comparative analysis of Resourcesat-2 LISS-3 and Landast-8 OLI imagery

    NASA Astrophysics Data System (ADS)

    Venkateswarlu, E.; Sivannarayana, T.; Ratna Kumar, K. V.

    2014-11-01

    Linear Imaging Self Scanning Sensor (LISS-3) onboard Resoucesat-1 and 2 Satellites have been used extensively for various land cover-land use applications. In this study, we examined the potential of using Resourcesat-2 LISS-3 images in the absence of LANDSAT-8 Operational Land Imager (OLI) images. This paper compares the capabilities of LISS-3 sensor with OLI sensor. LISS-3 images were selected for comparison because of their close resemblance in electromagnetic spectrum range with LS-8 OLI images. Images of LS-8 OLI and RS-2 LISS-3 of the same area in Andhra Pradesh were used to evaluate the comparative performances based on the intra-inter band correlation, spectral vegetation indices and land cover classification. The results showed that in most cases the LS-8 OLI and the RS-2 LISS-3 images are comparable. This study also indicated that LISS-3 images could fill the data gaps in OLI images for land-cover studies, vice versa.

  4. Investigating the Capability of IRS-P6-LISS IV Satellite Image for Pistachio Forests Density Mapping (case Study: Northeast of Iran)

    NASA Astrophysics Data System (ADS)

    Hoseini, F.; Darvishsefat, A. A.; Zargham, N.

    2012-07-01

    In order to investigate the capability of satellite images for Pistachio forests density mapping, IRS-P6-LISS IV data were analyzed in an area of 500 ha in Iran. After geometric correction, suitable training areas were determined based on fieldwork. Suitable spectral transformations like NDVI, PVI and PCA were performed. A ground truth map included of 34 plots (each plot 1 ha) were prepared. Hard and soft supervised classifications were performed with 5 density classes (0-5%, 5-10%, 10-15%, 15-20% and > 20%). Because of low separability of classes, some classes were merged and classifications were repeated with 3 classes. Finally, the highest overall accuracy and kappa coefficient of 70% and 0.44, respectively, were obtained with three classes (0-5%, 5-20%, and > 20%) by fuzzy classifier. Considering the low kappa value obtained, it could be concluded that the result of the classification was not desirable. Therefore, this approach is not appropriate for operational mapping of these valuable Pistachio forests.

  5. Loss of enzyme-sensitive antigens due to the presence of leukocytes, neomycin sulfate, and LISS.

    PubMed

    Velliquette, R W; Howard, P; Malyska, H; Reid, M E

    2003-01-01

    Previous studies have shown that RBCs with residual WBCs stored in LISS and neomycin sulfate develop characteristics associated with enzyme-treated RBCs. During a mass screening program to antigen type donor RBCs, we observed that the Fya antigens on a RBC sample from an in-house panel became non-detectable with anti-Fya after incubation overnight in Diluent 2 from Micro Typing Systems, Inc. (MTS, Pompano Beach, FL). In response to this observation, we initiated an investigation to determine the cause. Tests were performed according to the manfacturer's instructions in MTS neutral gel cards or gel cards containing anti-IgG. We found that a reduction or loss of the Fya, Fyb, and M antigens occurs when RBCs were prepared from samples containing residual WBCs (as a source of enzymes) and subsequently incubated in media containing neomycin sulfate and LISS. We showed that the effect did not occur in the absence of neomycin sulfate. RBC antigens can be altered in LISS if they have first been exposed to neomycin. We recommend restricting the use of RBCs suspended in MTS Diluent 2 to the day of dilution (as indicated in the package insert) if preparing reagent RBCs from sources that were not leukoreduced and were stored in the presence of neomycin.

  6. Classification of Liss IV Imagery Using Decision Tree Methods

    NASA Astrophysics Data System (ADS)

    Verma, Amit Kumar; Garg, P. K.; Prasad, K. S. Hari; Dadhwal, V. K.

    2016-06-01

    Image classification is a compulsory step in any remote sensing research. Classification uses the spectral information represented by the digital numbers in one or more spectral bands and attempts to classify each individual pixel based on this spectral information. Crop classification is the main concern of remote sensing applications for developing sustainable agriculture system. Vegetation indices computed from satellite images gives a good indication of the presence of vegetation. It is an indicator that describes the greenness, density and health of vegetation. Texture is also an important characteristics which is used to identifying objects or region of interest is an image. This paper illustrate the use of decision tree method to classify the land in to crop land and non-crop land and to classify different crops. In this paper we evaluate the possibility of crop classification using an integrated approach methods based on texture property with different vegetation indices for single date LISS IV sensor 5.8 meter high spatial resolution data. Eleven vegetation indices (NDVI, DVI, GEMI, GNDVI, MSAVI2, NDWI, NG, NR, NNIR, OSAVI and VI green) has been generated using green, red and NIR band and then image is classified using decision tree method. The other approach is used integration of texture feature (mean, variance, kurtosis and skewness) with these vegetation indices. A comparison has been done between these two methods. The results indicate that inclusion of textural feature with vegetation indices can be effectively implemented to produce classifiedmaps with 8.33% higher accuracy for Indian satellite IRS-P6, LISS IV sensor images.

  7. Core Outlet Temperature Study

    SciTech Connect

    Moisseytsev, A.; Hoffman, E.; Majumdar, S.

    2008-07-28

    It is a known fact that the power conversion plant efficiency increases with elevation of the heat addition temperature. The higher efficiency means better utilization of the available resources such that higher output in terms of electricity production can be achieved for the same size and power of the reactor core or, alternatively, a lower power core could be used to produce the same electrical output. Since any nuclear power plant, such as the Advanced Burner Reactor, is ultimately built to produce electricity, a higher electrical output is always desirable. However, the benefits of the higher efficiency and electricity production usually come at a price. Both the benefits and the disadvantages of higher reactor outlet temperatures are analyzed in this work.

  8. Emulation of LISS III images for high temporal resolution at larger swath

    NASA Astrophysics Data System (ADS)

    Rao, C. V.; Malleswara Rao, J.; Senthil Kumar, A.; Lakshmi, B.; Dadhwal, V. K.

    2014-11-01

    Space borne sensors have limited capability to acquire images at high spatial and high temporal resolutions with larger swath simultaneously. In this paper, we propose alternatives to overcome this limitation by emulating such images at ground data processing system. Resourcesat-2, one of the Indian Space Research Organization's (ISRO) mission carries Linear Imaging Self-Scanners (LISS III and LISS-IV) and an Advanced Wide-Field Sensor (AWiFS) onboard. The spatial and temporal resolutions of LISS III are 23.5 m and 24 days, and those of AWiFS are 56 m and 5 days, respectively. The 141 km swath of LISS III data is overlapped with the 740 km swath of AWiFS data at centre portion in simultaneous acquisition. Two novel approaches are proposed to emulate the LISS III image with 740 km swath at 23.5 m spatial and 5-days temporal resolutions. First approach is to emulate the synthetic LISS III images at 23.5 m spatial and 5-days temporal resolutions. Mosaic such images to cover the full 740 km swath of AWiFS for a given date. First approach is achieved through a spatio-temporal data fusion technique which depends on the previously acquired single AWiFS-LISS III image pair. Second approach assumes that the non-overlapping region of AWiFS contains similar Earth's surface features of LISS III overlapping region; then it is possible to enhance the spatial resolution of AWiFS to the spatial resolution of LISS III in the nonoverlapping region. It is achieved through a single-image-super resolution technique over Non-sub sampled Contourlet Transform. First approach is computationally efficient but it requires prior knowledge of a single AWiFS-LISS III image pair for each emulated LISS III image. That image pair is acquired before or after the prediction date. Also, first approach faces radiometric issues in the mosaic process. Second approach has high computational complexity. But it works well for the data sets which are satisfying the above basic assumption. An accuracy of

  9. Comparison of FLAASH and QUAC atmospheric correction methods for Resourcesat-2 LISS-IV data

    NASA Astrophysics Data System (ADS)

    Saini, V.; Tiwari, R. K.; Gupta, R. P.

    2016-05-01

    The LISS-IV sensor aboard Resourcesat-2 is a modern relatively high resolution multispectral sensor having immense potential for generation of good quality land use land cover maps. It generates data in high (10-bit) radiometric resolution and 5.8 m spatial resolution and has three bands in the visible-near infrared region. This is of particular importance to global community as the data are provided at highly competitive prices. However, no literature describing the atmospheric correction of Resourcesat-2-LISS-IV data could be found. Further, without atmospheric correction full radiometric potential of any remote sensing data remains underutilized. The FLAASH and QUAC module of ENVI software are highly used by researchers for atmospheric correction of popular remote sensing data such as Landsat, SPOT, IKONOS, LISS-I, III etc. This article outlines a methodology for atmospheric correction of Resourcesat-2-LISS-IV data. Also, a comparison of reflectance from different atmospheric correction modules (FLAASH and QUAC) with TOA and standard data has been made to determine the best suitable method for reflectance estimation for this sensor.

  10. The Core Journal Concept in Black Studies

    ERIC Educational Resources Information Center

    Weissinger, Thomas

    2010-01-01

    Black Studies scholars have shown interest in the core journal concept. Indeed, the idea of core journals for the study of the Black experience has changed several times since 1940. While Black Studies scholars are citing Black Studies journals with frequency, they also cite traditional disciplinary journals a great deal of the time. However,…

  11. Pre-flight radiometric and spectral calibration of Resourcesat-2A-LISS3* payload

    NASA Astrophysics Data System (ADS)

    Seth, Harish; Detroja, M. P.; Padmanabhan, Deepa; Raj, Vedant; Kumar, Anil; Sarkar, S. S.

    2016-05-01

    Resourcesat-2A is a follow-on mission of Resourcesat-2, belongs to Indian Remote Sensing Program. It is expected to be launched in 2016 and is dedicated mainly to agricultural applications. One of the payloads, LISS3* is a medium resolution (23.5 m) sensor having four multispectral bands from 450 to 1650 nm. These spectral bands are named as B2 (550 nm), B3 (650 nm), B4 (815 nm) and B5 (1625 nm) respectively covering Visible, Near Infrared (NIR) and Short Wave Infrared (SWIR) regions. In order to provide quality data to the user community for long term scientific applications pre-flight ground calibration is carried out. This paper describes pre-flight spectral and radiometric calibration of LISS3* payload and its performance evaluation. Since it is a continuity mission to Resourcesat-2, which was launched in April 2011 so for generating long-term data record and correlation with previous observations, its parameters are compared with Resourcesat-2 LISS3* payload. The main spectral parameters like central wavelength, and pass band is determined using system level spectral response and compared for both the mission and differences are outlined. The next important exercise is pre-flight radiometric calibration, which was carried out in laboratory using a standard integrating sphere traceable to NIST standards. This paper highlights the technique adopted during pre-flight calibration of the radiometric response and performance assessment of all 4 bands of LISS3* in terms of major electro-optical parameters like Signal to Noise Ratio (SNR), Saturation Radiance (SR) etc. The observed SR shows that the sensor can measure spectral radiance from Earth up to 100% albedo.

  12. Improving classification accuracy using multi-date IRS/LISS data and development of thermal stress index for Asiatic lion habitat

    NASA Astrophysics Data System (ADS)

    Gupta, Rajendra Kumar

    The increase in lion and leopard population in the GIR wild life sanctuary and National Park (Gir Protected Area) demands periodic and precision monitoring of habitat at close intervals using space based remote sensing data. Besides characterizing the different forest classes, remote sensing needs to support for the assessment of thermal stress zones and identification of possible corridors for lion dispersion to new home ranges. The study focuses on assessing the thematic forest classification accuracies in percentage terms(CA) attainable using single date post-monsoon (CA=60, kappa = 0.514) as well as leaf shedding (CA=48.4, kappa = 0.372) season data in visible and Near-IR spectral bands of IRS/LISS-III at 23.5 m spatial resolution; and improvement of CA by using joint two date (multi-temporal) data sets (CA=87.2, kappa = 0.843) in the classification. The 188 m spatial resolution IRS/WiFS and 23.5 m spatial resolution LISS-III data were used to study the possible corridors for dispersion of Lions from GIR protected areas (PA). A relative thermal stress index (RTSI) for Gir PA has been developed using NOAA/ AVHRR data sets of post-monsoon, leaf shedded and summer seasons. The paper discusses the role of RTSI as a tool to work out forest management plans using leaf shedded season data to combat the thermal stress in the habitat, by identifying locations for artificial water holes during the ensuing summer season.

  13. Assessment of water quality parameters of the Harike wetland in India, a Ramsar site, using IRS LISS IV satellite data.

    PubMed

    Mabwoga, Samson Okongo; Chawla, Amit; Thukral, Ashwani Kumar

    2010-11-01

    This study aims at the classification and water quality assessment of Harike wetland (Ramsar site) in India using satellite images from the Indian Remote Sensing satellite, Resourcesat (IRS P6). The Harike wetland is a converging zone of two rivers, Beas and Sutlej. The satellite images of IRS Linear Imaging Self Scanner (LISS) IV multispectral sensor with three bands (green, red, and near infrared (NIR)) and a spatial resolution of 5.8 m were classified using supervised image classification techniques. Field points for image classification and water sampling were recorded using a Garmin eTrex Global Positioning System. The water quality parameters assessed were dissolved oxygen, conductivity, pH, turbidity, total and suspended solids (SS), chemical oxygen demand, and Secchi disk transparency (SDT). Correlations were established between turbidity and SS, SS and SDT, and total solids and turbidity. Using reflectance values from the green, red, and NIR bands, we then plotted the water quality parameters with the mean digital number values from the satellite imagery. The NIR band correlated significantly with the water quality parameters, whereas, using SDT values, it was observed that the green and the red reflectance bands were able to distinguish the waters from the two rivers, which have different water qualities. PMID:19882220

  14. Automated Registration of Images from Multiple Bands of Resourcesat-2 Liss-4 camera

    NASA Astrophysics Data System (ADS)

    Radhadevi, P. V.; Solanki, S. S.; Jyothi, M. V.; Varadan, G.

    2014-11-01

    Continuous and automated co-registration and geo-tagging of images from multiple bands of Liss-4 camera is one of the interesting challenges of Resourcesat-2 data processing. Three arrays of the Liss-4 camera are physically separated in the focal plane in alongtrack direction. Thus, same line on the ground will be imaged by extreme bands with a time interval of as much as 2.1 seconds. During this time, the satellite would have covered a distance of about 14 km on the ground and the earth would have rotated through an angle of 30". A yaw steering is done to compensate the earth rotation effects, thus ensuring a first level registration between the bands. But this will not do a perfect co-registration because of the attitude fluctuations, satellite movement, terrain topography, PSM steering and small variations in the angular placement of the CCD lines (from the pre-launch values) in the focal plane. This paper describes an algorithm based on the viewing geometry of the satellite to do an automatic band to band registration of Liss-4 MX image of Resourcesat-2 in Level 1A. The algorithm is using the principles of photogrammetric collinearity equations. The model employs an orbit trajectory and attitude fitting with polynomials. Then, a direct geo-referencing with a global DEM with which every pixel in the middle band is mapped to a particular position on the surface of the earth with the given attitude. Attitude is estimated by interpolating measurement data obtained from star sensors and gyros, which are sampled at low frequency. When the sampling rate of attitude information is low compared to the frequency of jitter or micro-vibration, images processed by geometric correction suffer from distortion. Therefore, a set of conjugate points are identified between the bands to perform a relative attitude error estimation and correction which will ensure the internal accuracy and co-registration of bands. Accurate calculation of the exterior orientation parameters with

  15. Social Studies Core Curriculum, K-6.

    ERIC Educational Resources Information Center

    Utah State Office of Education, Salt Lake City.

    This guide outlines the core social studies course standards for Utah elementary schools. Using a graphic format, the guide delineates each course--beginning with Kindergarten and concluding with Level 6. It describes the course; lists column headings for time, people, and places; cites the appropriate standard; and educational objectives to be…

  16. Monitoring Environment with GIS for Part of Thiruvallur Town Using Cartosat 1 Stereo, Pan & Resourcesat Liss 4 MSS Merged Data

    NASA Astrophysics Data System (ADS)

    Mohamed, G. S.; Venkatchalam, R. V.; Ramamurthhy, M.; Gummidipoondi, R. J.; Ramillah, M.

    2012-07-01

    Thiruvallur town is about 44 km from Chennai in Tamil nadu state of India with a population of 130000 , covering 10.75 sq km area. It is about 2km from Sri Venkateswara College of Engineering and Technology. It was Taluk (Sub Division'.s) head quarters and from 1991 it was upgraded as District head quarters after the formation of Thiruvallur District. With rapid growth of town the Population density of Thiruvallur has increased in the past three decades from 300 persons/sq.km in 1951, to 6000 persons/sq.km in 1981 and now it is 12925 persons/sq.km in 2011. The creation of District administrative collector office, headquarters offices for police, judicial courts and Tamil Nadu and Federal Government development department's offices, establishment of multinationals major industries like Caterpillar, Kingfishers,Hindustan Motors, Mahendra Automobiles, Coco cola, Japanese Glass industry, Korean LOTO etc apart from mushrooming growth of about 41 Engineering, Nursing, Education, Medical, Naval, Arts and Science colleges, International Public schools,Governmentt, Private schools and Polytechnics added to the population of this Town. It is well connected by National Highways and Railways and upgraded as District Municipality. This resulted in urban drainage problem and conversion of Agriculture land and lakes for housing, establishment of major Govt and Private Hospitals including special units for Eye care, Cardiology, and Health Clinics, pharmacies etc. The effect of urbanization on environment of this once silent rural temple town which was supporting intensive agriculture activities , green with paddy fields is studied with high resolution satellite data is know the impact on health and environment changes from 2008 to 2011, using 2.5m resolution PAN stereo data of Cartosat 1 merged with 5.8 m resolution Multi Spectral data of LISS 4 of Resourcesat 1 of Indian Remote sensing satellites and Geo Eye satellite image of 2011 from Google Earth web site for the western part

  17. Cardiovascular Deconditioning in Humans: Human Studies Core

    NASA Technical Reports Server (NTRS)

    Williams, Gordon

    1999-01-01

    Major cardiovascular problems, secondary to cardiovascular deconditioning, may occur on extended space missions. While it is generally assumed that the microgravity state is the primary cause of cardiovascular deconditioning, sleep deprivation and disruption of diurnal rhythms may also play an important role. Factors that could be modified by either or both of these perturbations include: autonomic function and short-term cardiovascular reflexes, vasoreactivity, circadian rhythm of cardiovascular hormones (specifically the renin-angiotensin system) and renal sodium handling and hormonal influences on that process, venous compliance, cardiac mass, and cardiac conduction processes. The purpose of the Human Studies Core is to provide the infrastructure to conduct human experiments which will allow for the assessment of the likely role of such factors in the space travel associated cardiovascular deconditioning process and to develop appropriate countermeasures. The Core takes advantage of a newly-created Intensive Physiologic Monitoring (IPM) Unit at the Brigham and Women's Hospital, Boston, MA, to perform these studies. The Core includes two general experimental protocols. The first protocol involves a head down tilt bed-rest study to simulate microgravity. The second protocol includes the addition of a disruption of circadian rhythms to the simulated microgravity environment. Before and after each of these environmental manipulations, the subjects will undergo acute stressors simulating changes in volume and/or stress, which could occur in space and on return to Earth. The subjects are maintained in a rigidly controlled environment with fixed light/dark cycles, activity pattern, and dietary intake of nutrients, fluids, ions and calories.

  18. Magnetic core studies at LBNL and LLNL

    SciTech Connect

    Molvik, A.W.; Faltens, A.; Reginato, L.; Blaszkiewicz, M.; Smith, C.; Wood, R.

    1997-09-20

    The objective of this work is to minimize the cost of the materials and maximize the performance of magnetic cores, a major cost component of a Heavy-Ion-Fusion, HIF, induction accelerator driver. This includes selection of the alloy for cost and performance, and maximizing the performance of each alloy evaluated. The two major performance parameters are the magnetic flux swing and the energy loss. The volt seconds of the cores, obtained from the flux swing with Faraday's Law, determines the beam energy and duration. Core losses from forming domains and moving their boundaries are a major factor in determining the efficiency of an induction accelerator.

  19. Preserving Social Studies as Core Curricula in an Era of Common Core Reform

    ERIC Educational Resources Information Center

    Denton, David W.; Sink, Cindy

    2015-01-01

    Education reform over the last two decades has changed perceptions of core curricula. Although social studies has traditionally been part of the core, emphasis on standards-based teaching and learning, along with elaborate accountability schemes, is causing unbalanced treatment of subjects. While the research literature indicates teachers are…

  20. Core compressor exit stage study, 2

    NASA Technical Reports Server (NTRS)

    Behlke, R. F.; Burdsall, E. A.; Canal, E., Jr.; Korn, N. D.

    1979-01-01

    A total of two three-stage compressors were designed and tested to determine the effects of aspect ratio on compressor performance. The first compressor was designed with an aspect ratio of 0.81; the other, with an aspect ratio of 1.22. Both compressors had a hub-tip ratio of 0.915, representative of the rear stages of a core compressor, and both were designed to achieve a 15.0% surge margin at design pressure ratios of 1.357 and 1.324, respectively, at a mean wheel speed of 167 m/sec. At design speed the 0.81 aspect ratio compressor achieved a pressure ratio of 1.346 at a corrected flow of 4.28 kg/sec and an adiabatic efficiency of 86.1%. The 1.22 aspect ratio design achieved a pressure ratio of 1.314 at 4.35 kg/sec flow and 87.0% adiabatic efficiency. Surge margin to peak efficiency was 24.0% with the lower aspect ratio blading, compared with 12.4% with the higher aspect ratio blading.

  1. Pre-conceptual design study of ASTRID core

    SciTech Connect

    Varaine, F.; Marsault, P.; Chenaud, M. S.; Bernardin, B.; Conti, A.; Sciora, P.; Venard, C.; Fontaine, B.; Devictor, N.; Martin, L.; Scholer, A. C.; Verrier, D.

    2012-07-01

    In the framework of the ASTRID project at CEA, core design studies are performed at CEA with the AREVA and EDF support. At the stage of the project, pre-conceptual design studies are conducted in accordance with GEN IV reactors criteria, in particularly for safety improvements. An improved safety for a sodium cooled reactor requires revisiting many aspects of the design and is a rather lengthy process in current design approach. Two types of cores are under evaluation, one classical derived from the SFR V2B and one more challenging called CFV (low void effect core) with a large gain on the sodium void effect. The SFR V2b core have the following specifications: a very low burn-up reactivity swing (due to a small cycle reactivity loss) and a reduced sodium void effect with regard to past designs such as the EFR (around 2$ minus). Its performances are an average burn-up of 100 GWd/t, and an internal conversion ratio equal to one given a very good behavior of this core during a control rod withdrawal transient). The CFV with its specific design offers a negative sodium void worth while maintaining core performances. In accordance of ASTRID needs for demonstration those cores are 1500 MWth power (600 MWe). This paper will focus on the CFV pre-conceptual design of the core and S/A, and the performances in terms of safety will be evaluated on different transient scenario like ULOF, in order to assess its intrinsic behavior compared to a more classical design like V2B core. The gap in term of margin to a severe accident due to a loss of flow initiator underlines the potential capability of this type of core to enhance prevention of severe accident in accordance to safety demonstration. (authors)

  2. Feasibility study of full-reactor gas core demonstration test

    NASA Technical Reports Server (NTRS)

    Kunze, J. F.; Lofthouse, J. H.; Shaffer, C. J.; Macbeth, P. J.

    1973-01-01

    Separate studies of nuclear criticality, flow patterns, and thermodynamics for the gas core reactor concept have all given positive indications of its feasibility. However, before serious design for a full scale gas core application can be made, feasibility must be shown for operation with full interaction of the nuclear, thermal, and hydraulic effects. A minimum sized, and hence minimum expense, test arrangement is considered for a full gas core configuration. It is shown that the hydrogen coolant scattering effects dominate the nuclear considerations at elevated temperatures. A cavity diameter of somewhat larger than 4 ft (122 cm) will be needed if temperatures high enough to vaporize uranium are to be achieved.

  3. Genomic and Proteomic Studies on Plesiomonas shigelloides Lipopolysaccharide Core Biosynthesis

    PubMed Central

    Aquilini, Eleonora; Merino, Susana; Regué, Miguel

    2014-01-01

    We report here the identification of waa clusters with the genes required for the biosynthesis of the core lipopolysaccharides (LPS) of two Plesiomonas shigelloides strains. Both P. shigelloides waa clusters shared all of the genes besides the ones flanking waaL. In both strains, all of the genes were found in the waa gene cluster, although one common core biosynthetic gene (wapG) was found in a different chromosome location outside the cluster. Since P. shigelloides and Klebsiella pneumoniae share a core LPS carbohydrate backbone extending up at least to the second outer-core residue, the functions of the common P. shigelloides genes were elucidated by genetic complementation studies using well-defined K. pneumoniae mutants. The function of strain-specific inner- or outer-core genes was identified by using as a surrogate acceptor LPS from three well-defined K. pneumoniae core LPS mutants. Using this strategy, we were able to assign a proteomic function to all of the P. shigelloides waa genes identified in the two strains encoding six new glycosyltransferases (WapA, -B, -C, -D, -F, and -G). P. shigelloides demonstrated an important variety of core LPS structures, despite being a single species of the genus, as well as high homologous recombination in housekeeping genes. PMID:24244003

  4. Genomic and proteomic studies on Plesiomonas shigelloides lipopolysaccharide core biosynthesis.

    PubMed

    Aquilini, Eleonora; Merino, Susana; Regué, Miguel; Tomás, Juan M

    2014-02-01

    We report here the identification of waa clusters with the genes required for the biosynthesis of the core lipopolysaccharides (LPS) of two Plesiomonas shigelloides strains. Both P. shigelloides waa clusters shared all of the genes besides the ones flanking waaL. In both strains, all of the genes were found in the waa gene cluster, although one common core biosynthetic gene (wapG) was found in a different chromosome location outside the cluster. Since P. shigelloides and Klebsiella pneumoniae share a core LPS carbohydrate backbone extending up at least to the second outer-core residue, the functions of the common P. shigelloides genes were elucidated by genetic complementation studies using well-defined K. pneumoniae mutants. The function of strain-specific inner- or outer-core genes was identified by using as a surrogate acceptor LPS from three well-defined K. pneumoniae core LPS mutants. Using this strategy, we were able to assign a proteomic function to all of the P. shigelloides waa genes identified in the two strains encoding six new glycosyltransferases (WapA, -B, -C, -D, -F, and -G). P. shigelloides demonstrated an important variety of core LPS structures, despite being a single species of the genus, as well as high homologous recombination in housekeeping genes.

  5. Evaluation of Catrosat 1PAN Stereo and Resourcesat Liss 4 MSS Merged Data for Morphometric Analysis, Delineation of Drainage Basins and Codification in Tamil Nadu, India and Australia

    NASA Astrophysics Data System (ADS)

    Mohamed, G. S.; Srinivasan, S.; Pandian, R.; Gummidipoondi, R. J.; Venkatchalam, R. V.; Swaminathan. S, S.

    2012-07-01

    The Topographic maps and Aerial Photographs are used for morphometric analysis of drainage basins and mapping contours with drainage. The stereo pairs of 2.5 m resolution Cartosat 1, Indian satellite 2 and merged data with 5.5 m resolution P6 Resourcesat 1 LISS 4 Indian satellite of 2001 is used to map, rills, gullies, and streams of first order to evaluate part of drainage basin of Cooum and Poondi Reservoir in Thiruvallur taluk of Tamil Nadu state. The Geo Eye latest 2011data is also used with Catrosat 1Stereo data to study present morphology of tiny micro watersheds to study the use of High resolution data for delineation and codification of watersheds. This study area is in an inter fluvial drainage basin of Cooum and Kusasthalai rivers. Kusasthalai river drains in Poondi reservoir which is about 50 km from Chennai. The excess water from Kosasthalai is also diverted through Kesawaram weir to Cooum river which passes through Thiruvallur and Chennai city before it's confluence with Bay of Benegal in the east. As Cooum basin is at higher elevation, water for irrigation is again diverted through chain of tanks to Kusasthalai river basin to drain in Poondi reservoir. Delineation of water sheds in this fluvial basin is difficult by manual survey as man made irrigation channels, natural drainage streams etc., have to be clearly identified. The streams of various orders are identified based on Strahler stream order hierarchy of tributaries, slops and contours using large scale satellite data. The micro water sheds are delinated identifying the ridges from Catrosat data for this interfluves basin which has mild slop. To illustrate this research, parts of two micro watersheds which were delineated using 1:50000 data for Tamil Nadu watershed Atlas up to 7th order streams are taken up for a detailed study using high resolution data. 19 Micro watersheds with streams up to 10th order are mapped. The capability of high resolution satellite data for digital as well as visual

  6. Core compressor exit stage study, volume 6

    NASA Technical Reports Server (NTRS)

    Wisler, D. C.

    1981-01-01

    Rear stage blading designs that have lower losses in their endwall boundary layer regions were studied. A baseline Stage A was designed as a low-speed model of stage 7 of a 10-stage compressor. Candidate rotors and stators were designed which have the potential of reducing endwall losses relative to the baseline. Rotor B uses a type of meanline in the tip region that unloads the leading edge and loads the trailing edge relative to the baseline rotor A designs. Rotor C incorporates a more skewed (hub strong) radial distribution of total pressure and smoother distribution of static pressure on the rotor tip than those of rotor B. Candidate stator B embodies twist gradients in the endwall region. Stator C embodies airfoil sections near the endwalls that have reduced trailing edge loading relative to stator A. The baseline and candidate bladings were tested using four identical stages to produce a true multistage environment. Single-stage tests were also conducted. The test data were analyzed and performances were compared. Several of the candidate configurations showed a performance improvement relative to the baseline.

  7. Implications of Common Core State Standards on the Social Studies

    ERIC Educational Resources Information Center

    Kenna, Joshua L.; Russell, William B., III.

    2014-01-01

    Social studies teachers have often been on the outside looking in during much of the era billed as the standards-based educational reform (SBER), but with the adoption and implementation of the Common Core State Standards (CCSS), social studies teachers seem to have been invited back inside. Yet, how will the standards impact social studies…

  8. Core design studies for advanced burner test reactor.

    SciTech Connect

    Yang, W. S.; Kim, T. K.; Hill, R. N.; Nuclear Engineering Division

    2008-01-01

    The U.S. government announced in February 2006 the Global Nuclear Energy Partnership (GNEP) to expand the use of nuclear energy to meet increasing global energy demand, to address nuclear waste management concerns and to promote non-proliferation. The advanced burner reactor (ABR) based on a fast spectrum is one of the three major technologies to be demonstrated in GNEP. In FY06, a pre-conceptual design study was performed to develop an advanced burner test reactor (ABTR) that supports development of a prototype full-scale ABR, which would be followed by commercial deployment of ABRs. The primary objectives of the ABTR were (1) to demonstrate reactor-based transmutation of transuranics (TRU) as part of an advanced fuel cycle, (2) to qualify the TRU-containing fuels and advanced structural materials needed for a full-scale ABR, (3) to support the research, development and demonstration required for certification of an ABR standard design by the U.S. Nuclear Regulatory Commission. Based on these objectives, core design and fuel cycle studies were performed to develop ABTR core designs, which can accommodate the expected changes of the TRU feed and the conversion ratio. Various option and trade-off studies were performed to determine the appropriate power level and conversion ratio. Both ternary metal alloy (U-TRU-10Zr) and mixed oxide (UO{sub 2}-TRUO{sub 2}) fuel forms have been considered with TRU feeds from weapons-grade plutonium (WG-Pu) and TRU recovered from light water reactor spent fuel (LWR-SF). Reactor performances were evaluated in detail including equilibrium cycle core parameters, mass flow, power distribution, kinetic parameters, reactivity feedback coefficient, reactivity control requirements and shutdown margins, and spent fuel characteristics. Trade-off studies on power level suggested that about 250 MWt is a reasonable compromise to allow a low project cost, at the same time providing a reasonable prototypic irradiation environment for demonstrating

  9. A Numerical Study on Possible Driving Mechanisms of Core Convection

    NASA Astrophysics Data System (ADS)

    Breuer, M.; Harder, H.; Hansen, U.

    2005-12-01

    We present a numerical study on core convection based on a model of a rotating spherical shell where different driving mechanisms are investigated. Two different sources are potentially available to act as driving forces. The first is based on the super adiabatic temperature gradient in the outer core. The second is of chemical nature and is derived from light elements which emerge at the boundary between the inner and the outer core as a result of the freezing process of the outer core. So far it is uncertain if the convective flow in the outer core is dominated by thermal or by chemical buoyancy. Dynamically, both components differ mainly in terms of their diffusional time scales, whereas the chemical component diffuses much faster than the thermal one. To investigate the influence of the driving mechanisms on the convective flow pattern we considered different scenarios including the two extreme cases of purely thermal and purely chemical driven convection and the more likely situation of a joint action of both sources. We focused on the question how the driving mechanisms affects the differential rotation and the spatial distribution of helicity which are particularly important for the dynamo process.

  10. Social Studies Core Curriculum in Fieldston Lower School.

    ERIC Educational Resources Information Center

    Kuhmerker, Lisa, Ed.

    1983-01-01

    An overview is presented of an elementary-level social studies core curriculum at Fieldston Lower School (in New York City) in which the moral and ethical development of students is seen as a priority. Fieldston Lower School is one of three branches of the Ethical Culture Schools. Article 1 focuses on the modification of the traditional elementary…

  11. Core Curriculum for Social Studies Education K-12.

    ERIC Educational Resources Information Center

    Utah State Office of Education, Salt Lake City. Office of Curriculum and Instruction.

    The Utah social studies curriculum for grades K-12 is divided into three levels: K-6, 7-8, and 9-12. For K-6, mastery of core concepts is required; for grades 7-8, 1.5 units of United States History and Utah studies are required; and for grades 9-12, three units of world cultural geography, ancient world civilizations, European history, United…

  12. Paleomagnetic Study of Core MD012380 from Banda Sea

    NASA Astrophysics Data System (ADS)

    Lee, T.; Huang, Y.; Chen, C.; Yang, T.; Hsu, S.; Wei, K.

    2003-12-01

    This study presents the paleomagnetic results of core MD012380 taken from Banda Sea during IMAGES VII cruise in 2001. The locality of the coring site is 126o 54.25­ÝE and 5o45.64­ÝS, and the water depth is about 3232m. The total recovered length of this core is 39.9 m. The simulated paleo-intensity pattern is well correlated to that of the SINT 800 (Guyodo and Valet, 1999). Several magnetic events and excursions, such as Blake, Jarmaica, Lavantine, Big Lost Emperor, Delta and B/M Boundary could be identified. These events appeared at the depths of about 13.84 m, 18.05 m, 22.75 m, 31.81 m, 35.89 m, 38.70 m, respectively. Paleoinclination data also indicate that the boundary of Brunhes and Matuyama epochs appeared at the depth of 38.7 m. So, the paleomagnetic result is used to construct the age model of this core. Then, apply it to the studied oxygen isotope pattern and compare to that proposed by Bassinot et al. (1994), they are well correlated. In addition, the LAD of P. lacunosa is found at the depth of 28.4 m, which also supports the proposed age model. Result of magnetic susceptibility (c) shows several high peaks, especially at the bottom portion, which might relate to the volcanic activity in the surrounding area. Generally, high values occurred at the interglacial periods and low values appeared at the interglacial periods. However, magnetic susceptibility has a special increasing trend from stage 8 to the early stage 5. It may be worthy of further study.

  13. Neutrino oscillation studies with IceCube-DeepCore

    NASA Astrophysics Data System (ADS)

    Aartsen, M. G.; Abraham, K.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Altmann, D.; Anderson, T.; Ansseau, I.; Archinger, M.; Arguelles, C.; Arlen, T. C.; Auffenberg, J.; Bai, X.; Barwick, S. W.; Baum, V.; Bay, R.; Beatty, J. J.; Becker Tjus, J.; Becker, K.-H.; Beiser, E.; Berghaus, P.; Berley, D.; Bernardini, E.; Bernhard, A.; Besson, D. Z.; Binder, G.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Börner, M.; Bos, F.; Bose, D.; Böser, S.; Botner, O.; Braun, J.; Brayeur, L.; Bretz, H.-P.; Buzinsky, N.; Casey, J.; Casier, M.; Cheung, E.; Chirkin, D.; Christov, A.; Clark, K.; Classen, L.; Coenders, S.; Collin, G. H.; Conrad, J. M.; Cowen, D. F.; Cruz Silva, A. H.; Daughhetee, J.; Davis, J. C.; Day, M.; de André, J. P. A. M.; De Clercq, C.; del Pino Rosendo, E.; Dembinski, H.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de Wasseige, G.; de With, M.; DeYoung, T.; Díaz-Vélez, J. C.; di Lorenzo, V.; Dumm, J. P.; Dunkman, M.; Eberhardt, B.; Ehrhardt, T.; Eichmann, B.; Euler, S.; Evenson, P. A.; Fahey, S.; Fazely, A. R.; Feintzeig, J.; Felde, J.; Filimonov, K.; Finley, C.; Flis, S.; Fösig, C.-C.; Fuchs, T.; Gaisser, T. K.; Gaior, R.; Gallagher, J.; Gerhardt, L.; Ghorbani, K.; Gier, D.; Gladstone, L.; Glagla, M.; Glüsenkamp, T.; Goldschmidt, A.; Golup, G.; Gonzalez, J. G.; Góra, D.; Grant, D.; Griffith, Z.; Groß, A.; Ha, C.; Haack, C.; Haj Ismail, A.; Hallgren, A.; Halzen, F.; Hansen, E.; Hansmann, B.; Hanson, K.; Hebecker, D.; Heereman, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hignight, J.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Holzapfel, K.; Homeier, A.; Hoshina, K.; Huang, F.; Huber, M.; Huelsnitz, W.; Hulth, P. O.; Hultqvist, K.; In, S.; Ishihara, A.; Jacobi, E.; Japaridze, G. S.; Jeong, M.; Jero, K.; Jones, B. J. P.; Jurkovic, M.; Kappes, A.; Karg, T.; Karle, A.; Kauer, M.; Keivani, A.; Kelley, J. L.; Kemp, J.; Kheirandish, A.; Kiryluk, J.; Klein, S. R.; Kohnen, G.; Koirala, R.; Kolanoski, H.; Konietz, R.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krings, K.; Kroll, G.; Kroll, M.; Krückl, G.; Kunnen, J.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Lanfranchi, J. L.; Larson, M. J.; Lesiak-Bzdak, M.; Leuermann, M.; Leuner, J.; Lu, L.; Lünemann, J.; Madsen, J.; Maggi, G.; Mahn, K. B. M.; Mandelartz, M.; Maruyama, R.; Mase, K.; Matis, H. S.; Maunu, R.; McNally, F.; Meagher, K.; Medici, M.; Meli, A.; Menne, T.; Merino, G.; Meures, T.; Miarecki, S.; Middell, E.; Mohrmann, L.; Montaruli, T.; Morse, R.; Nahnhauer, R.; Naumann, U.; Neer, G.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Obertacke Pollmann, A.; Olivas, A.; Omairat, A.; O'Murchadha, A.; Palczewski, T.; Pandya, H.; Pankova, D. V.; Paul, L.; Pepper, J. A.; Pérez de los Heros, C.; Pfendner, C.; Pieloth, D.; Pinat, E.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Quinnan, M.; Raab, C.; Rädel, L.; Rameez, M.; Rawlins, K.; Reimann, R.; Relich, M.; Resconi, E.; Rhode, W.; Richman, M.; Richter, S.; Riedel, B.; Robertson, S.; Rongen, M.; Rott, C.; Ruhe, T.; Ryckbosch, D.; Sabbatini, L.; Sander, H.-G.; Sandrock, A.; Sandroos, J.; Sarkar, S.; Schatto, K.; Schimp, M.; Schmidt, T.; Schoenen, S.; Schöneberg, S.; Schönwald, A.; Schulte, L.; Schumacher, L.; Seckel, D.; Seunarine, S.; Soldin, D.; Song, M.; Spiczak, G. M.; Spiering, C.; Stahlberg, M.; Stamatikos, M.; Stanev, T.; Stasik, A.; Steuer, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Ström, R.; Strotjohann, N. L.; Sullivan, G. W.; Sutherland, M.; Taavola, H.; Taboada, I.; Tatar, J.; Ter-Antonyan, S.; Terliuk, A.; Tešić, G.; Tilav, S.; Toale, P. A.; Tobin, M. N.; Toscano, S.; Tosi, D.; Tselengidou, M.; Turcati, A.; Unger, E.; Usner, M.; Vallecorsa, S.; Vandenbroucke, J.; van Eijndhoven, N.; Vanheule, S.; van Santen, J.; Veenkamp, J.; Vehring, M.; Voge, M.; Vraeghe, M.; Walck, C.; Wallace, A.; Wallraff, M.; Wandkowsky, N.; Weaver, Ch.; Wendt, C.; Westerhoff, S.; Whelan, B. J.; Wiebe, K.; Wiebusch, C. H.; Wille, L.; Williams, D. R.; Wills, L.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, D. L.; Xu, X. W.; Xu, Y.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zoll, M.

    2016-07-01

    IceCube, a gigaton-scale neutrino detector located at the South Pole, was primarily designed to search for astrophysical neutrinos with energies of PeV and higher. This goal has been achieved with the detection of the highest energy neutrinos to date. At the other end of the energy spectrum, the DeepCore extension lowers the energy threshold of the detector to approximately 10 GeV and opens the door for oscillation studies using atmospheric neutrinos. An analysis of the disappearance of these neutrinos has been completed, with the results produced being complementary with dedicated oscillation experiments. Following a review of the detector principle and performance, the method used to make these calculations, as well as the results, is detailed. Finally, the future prospects of IceCube-DeepCore and the next generation of neutrino experiments at the South Pole (IceCube-Gen2, specifically the PINGU sub-detector) are briefly discussed.

  14. Structural and spectral studies of sunspots. [umbral core modelling

    NASA Technical Reports Server (NTRS)

    Wyller, A. A.

    1974-01-01

    Observations of umbral cores, both by multicolor photometry and by narrow band photometry in the vicinity of the sodium D lines, are described, and evidence is given which supports the validity of many umbral models, each of which describes different aspects of the observed umbral cores. Theoretical studies carried on at the observatory include the following: (1) Zeeman profiles of the sodium D sub 2 line and other lines; (2) turbulent heat conduction, sound waves, and the missing flux in sunspots; (3) chromospheric heating above spots by Alfven waves; (4) magnetic convection in the sun and solar neutrinos; (5) models of starspots on flare stars; (5) starspots on the primaries of contact binary systems; and (6) implications of starspots on red dwarfs.

  15. Multi-Core Processor Memory Contention Benchmark Analysis Case Study

    NASA Technical Reports Server (NTRS)

    Simon, Tyler; McGalliard, James

    2009-01-01

    Multi-core processors dominate current mainframe, server, and high performance computing (HPC) systems. This paper provides synthetic kernel and natural benchmark results from an HPC system at the NASA Goddard Space Flight Center that illustrate the performance impacts of multi-core (dual- and quad-core) vs. single core processor systems. Analysis of processor design, application source code, and synthetic and natural test results all indicate that multi-core processors can suffer from significant memory subsystem contention compared to similar single-core processors.

  16. Spectroscopic studies of Synechococcus sp PCC 7002 phycobilisome core mutants

    SciTech Connect

    Gindt, Y.M.

    1993-04-01

    The role of the L[sub cm] (I), [beta][sup 18] (II), and [alpha][sup AP-B] (III) chromoproteins in the phycobilisome (PBS) core was investigated using genetically engineered strains of Synechococcus missing different polypeptides. Intact cells, isolated PBS, and subcore preparations for each mutant were studied to determine the effect of that mutation on energy transfer within the PBS core and to the reaction centers. Three mutants lacked the II and/or III polypeptides, while the I chromophore was altered in others. A lower energy absorbing chromophore, A[sub max] = 695 nm, was substituted for the I chromophore. The deletion of the II and III subunits had no discernible effect on energy transfer from the PBS to PSII. In cells and isolated PBS, the altered I chromophore acts to quench the PBS complex and to redirect the energy which would be transferred to PSII. In the PBS and subcore preparations, deletion of the III subunit did not alter energy transfer within the core. The deletion of the II subunit from the PBS caused a small decrease in the excited state lifetimes of the final emitters indicating more disorder within the core. The I chromophore was found to absorb at 670nm and to emit at 683nm within the intact PBS. The II chromophore emits at 679nm while the III chromophore emits at 682nm. A strong interaction exists between the I chromophore and the II subunit. Upon deletion of the II subunit from the PBS core, the I chromophore emits at a higher energy. The II subunit could act to stabilize the I chromophore-binding pocket, or exciton coupling could be occurring between the two. The role of the III chromophore is still unclear at this time. The III chromophore does contribute to the RT emission of the isolated PBS, but it transfers energy to I at 77 K. One can conclude that the III subunit is adjacent to the trimer containing the I polypeptide.

  17. Spectroscopic studies of Synechococcus sp PCC 7002 phycobilisome core mutants

    SciTech Connect

    Gindt, Y.M.

    1993-04-01

    The role of the L{sub cm} (I), {beta}{sup 18} (II), and {alpha}{sup AP-B} (III) chromoproteins in the phycobilisome (PBS) core was investigated using genetically engineered strains of Synechococcus missing different polypeptides. Intact cells, isolated PBS, and subcore preparations for each mutant were studied to determine the effect of that mutation on energy transfer within the PBS core and to the reaction centers. Three mutants lacked the II and/or III polypeptides, while the I chromophore was altered in others. A lower energy absorbing chromophore, A{sub max} = 695 nm, was substituted for the I chromophore. The deletion of the II and III subunits had no discernible effect on energy transfer from the PBS to PSII. In cells and isolated PBS, the altered I chromophore acts to quench the PBS complex and to redirect the energy which would be transferred to PSII. In the PBS and subcore preparations, deletion of the III subunit did not alter energy transfer within the core. The deletion of the II subunit from the PBS caused a small decrease in the excited state lifetimes of the final emitters indicating more disorder within the core. The I chromophore was found to absorb at 670nm and to emit at 683nm within the intact PBS. The II chromophore emits at 679nm while the III chromophore emits at 682nm. A strong interaction exists between the I chromophore and the II subunit. Upon deletion of the II subunit from the PBS core, the I chromophore emits at a higher energy. The II subunit could act to stabilize the I chromophore-binding pocket, or exciton coupling could be occurring between the two. The role of the III chromophore is still unclear at this time. The III chromophore does contribute to the RT emission of the isolated PBS, but it transfers energy to I at 77 K. One can conclude that the III subunit is adjacent to the trimer containing the I polypeptide.

  18. Isotope Fractionation Studies in Prestellar Cores: The Case of Nitrogen

    NASA Technical Reports Server (NTRS)

    Milam, Stefanie N.; Charnley, Steven B.

    2011-01-01

    Isotopically fractionated material is found in many solar system objects, including meteorites and comets. It is considered, in some cases, to trace interstellar material that was incorporated into the solar system without undergoing significant processing, thus preserving the fractionation. In interstellar molecular clouds, ion-molecule chemistry continually cycles nitrogen between the two main reservoirs - N and N2 - leading to only minor N-15 enrichments. Charnley and Rodgers showed that depletion of CO removes oxygen from the gas and weakens this cycle such that significant N-15 fractionation can occur for N2 and other N-bearing species in such cores. Observations are being conducted at millimeter and submillimeter wavelengths employing various facilities in order to both spatially and spectrally, resolve emission from these cores. A preliminary study to obtain the N-14/N-15 ratio in nitriles (HCN and HNC) was conducted at the Arizona Radio Observatory's 12m telescope on Kitt Peak, AZ. Spectra were obtained at high resolution (0.08 km/s) in order to resolve dynamic properties of each source as well as to resolve hyperfine structure present in certain isotopologues. This study included four dark cloud cores, observed to have varying levels of molecular depletion: L1521E, L1498, L1544, and L1521F. Previous studies of the N-14/N-15 ratio towards LI544 were obtained with N2H+ and NIH3, yielding ratios of 446 and >700, respectively. The discrepancy observed in these two measurements suggests a strong chemical dependence on the fractionation of nitrogen. Ratios (C,N, and D) obtained from isotopologues for a particular molecule are likely tracing the same chemical heritage and are directly comparable within a given source. Results and comparisons between the protostellar evolutionary state and isomer isotope fractionation as well as between other N-bearing species will be presented.

  19. Modes of Planetary Reshaping During Core Formation: Numerical Study

    NASA Astrophysics Data System (ADS)

    Lin, J.; Gerya, T. V.; Tackley, P. J.; Yuen, D. A.

    2007-12-01

    The early stages of terrestrial planetary accretion and differentiation related to core formation are largely enigmatic and require extensive realistic numerical modelling efforts especially in 2D(a cross-section of a spherical planet) and 3D geometries. One early stage of terrestrial planets was assumed to have a gravitationally unstable three-layer structure, the innermost undifferentiated solid core, the intermediate metal-melt layer, and the outermost silicate-melt layer, which leads to a Rayleigh-Taylor instability of various orders. We have developed a 2D thermomechanical numerical model for studying core formation in a self-gravitating planetary body surrounded by mass-less weak medium by using a combination of finite-differences with a Lagrangian marker-in-cell technique on a fully staggered Cartesian grid. We include a free planetary surface, spontaneously evolving gravity field, visco(elasto)plastic rheology of materials and feedback from shear heating. Benchmarking of this novel numerical method against available analytical solutions (Ida et al., 1987, Earth Moon Planets, 44, 149-174) has demonstrated high accuracy of the numerical results in the non inertial reshaping regime. Assuming the three-layered model (primordial protocore, metal and silicate layers) we investigated the influence of the viscosity contrast between the layers on the geometrical mode of planetary reshaping. In contrast to a previously conducted numerical study (Honda et al., 1993, JGR, 98, 2075-2089) we explored a broad range of viscosity ratios between the metallic layer and the protocore (0.001-1000) as well as between the silicate layer and the protocore (0.001-1000). A new important prediction from our study is that realistic modes of planetary reshaping characterized by a high viscosity contrast between the cold protocore and hot molten silicate layer always results in the transient exposure of the prorotocore to the planetary surface during the early stages of core formation

  20. Preliminary design study of advanced multistage axial flow core compressors

    NASA Technical Reports Server (NTRS)

    Wisler, D. C.; Koch, C. C.; Smith, L. H., Jr.

    1977-01-01

    A preliminary design study was conducted to identify an advanced core compressor for use in new high-bypass-ratio turbofan engines to be introduced into commercial service in the 1980's. An evaluation of anticipated compressor and related component 1985 state-of-the-art technology was conducted. A parametric screening study covering a large number of compressor designs was conducted to determine the influence of the major compressor design features on efficiency, weight, cost, blade life, aircraft direct operating cost, and fuel usage. The trends observed in the parametric screening study were used to develop three high-efficiency, high-economic-payoff compressor designs. These three compressors were studied in greater detail to better evaluate their aerodynamic and mechanical feasibility.

  1. Doppler Scanning of Sediment Cores: A Useful Method for Studying Sedimentary Structures and Defining the Cutting Angle for Half Cores

    NASA Astrophysics Data System (ADS)

    Acar, Dursun; Cagatay, Namik; Biltekin, Demet; Eris, Kadir; Albut, Gulum; Ogretmen, Nazik; Arslan, Tugce; Sari, Erol

    2014-05-01

    We tested the doppler ultrasound scanning of sediment cores in PVC liners using 8 megahertz ultrasonic waves for detection of angular laminations. The method was tested with artificially prepared cores as well as marine and lake sediment cores, and proven to be a useful and fast technique for imaging and determining the vertical angularity of sedimentary structures, such as laminations and beddings. Random cutting axes provide two angularities on X and Y dimensions. In this study, the main scientific problem is 'sequential angular disconformity'. Importance of detection of these anomalies on whole cores before dividing into half cores based on determining the right cutting axes. Successful imaging was obtained from top three centimeter depth of the sediments below the PVC liner, using a linear Doppler probe. Other Doppler probes (e.g., convex probe) did not work for core scanning because of their wave-form and reflection characteristics. Longitudinal and rotational scanning with gap filler and ultrasonic wave conductive gel material for keeping energy range of wave is necessary for detecting the variation in the dip of the bedding and laminae in the cores before separation. Another angular reasoned problem is about horizontal surface and can be easily solved with adjustable position of sensor or ray source placement. Border of sampling points between two different lithology must be stay with regard to neighbour sediment angles. Vertical angularity correction is not easy and its effect on signal propagation, detection biases and effectible to mixed samples contamination during physical sampling (particle size analyzing). Determining the attitude of angled bedding before core splitting is important for further core analyses such as elemental analysis and digital X-ray radiography. After Doppler scanning, the splitting direction (i.e., vertical to bedding and lamination) can be determined. The method is cheap, quick and non- hazardous to health, unlike the x

  2. Experimental study of the Biot coefficient of Bakken cores

    NASA Astrophysics Data System (ADS)

    Ma, X.; Zoback, M. D.

    2015-12-01

    We have performed a series of exhaustive experiments to measure the Biot coefficient (α) of the tight cores from the Bakken shale oil play. Five distinct, bedding-normal cores from a vertical well were tested, covering the sequences of Three Forks, Lower, Middle, and Upper Bakken, and Lodgepole. The scope of this laboratory study is two-fold: (1) to obtain realistic Biot coefficient for modeling reservoir stress changes due to depletion and injection; (2) to characterize the poromechanical properties in relation to rock's mineral composition and microstructure. The experiments were carried out as follows: Argon-saturated specimen (1-inch length, 1-inch diameter) was subjected to hydrostatic confining pressure under drained conditions. Pore pressure was regulated as Argon was injected into both ends of the specimen. We drilled multiple non-through-going boreholes (1-mm diameter) in the specimen to facilitate pressure equilibrium, without compromising its integrity. The specimen was put through a loading path to experience confining pressure and pore pressure up to 70 and 60 MPa, respectively. Axial and lateral strains were recorded and used to calculate the rock's bulk stiffness, and subsequently the static Biot coefficient, which is related to reservoir deformation and associated stress changes. Results of all five cores unanimously show that α is less than unity and is a function of both confining and pore pressure. α generally varies between 0.3 and 0.9 for the pressure levels we applied. This implies that models of reservoir deformation and its stress change using Terzaghi's simple effective stress law (α = 1) or a constant α less than 1 may be erroneous. Typically, α rises significantly with pore pressure, but declines with confining pressure to the degree that is dependent on rock's bulk stiffness. We found the stiffness of these rocks does not correlate well with the content of compliant components (e.g., clay and kerogen), and the drastic difference in

  3. Study on Spatial Cultural Heritage Integrated into the Core Curriculum

    NASA Astrophysics Data System (ADS)

    Hsu, W. H.; Lai, Y. P.

    2015-08-01

    These Many countries have put a lot of efforts, promoting education of cultural heritage, to raise the conservation awareness and increase people's participation. However, the development of Taiwan's higher education about cultural heritage has not shown a significant growth, so it didn't train talents with enough cultural heritage awareness. In the workplace, these professionals will inevitably lack of comprehensions and the appropriate professional assessments for cultural heritage. Hence, the main objective of this paper is to study and combine these concepts into the core curriculum of Department of Construction and Spatial Design at Tungnan University. It takes the local "Shenkeng historic cultural district" as a case study, and will gradually develop an proper interdisciplinary course in order to help local residents implement projects of conserving cultural heritage. This plan not only can increase schools' engagements toward communities, with an ability of social civilization, but also it can encourage the conservation and maintenance of cultural heritages.

  4. Core Outcomes for Colorectal Cancer Surgery: A Consensus Study

    PubMed Central

    Whistance, Robert N.; Forsythe, Rachael O.; Macefield, Rhiannon; Pullyblank, Anne M.; Avery, Kerry N. L.; Brookes, Sara T.; Thomas, Michael G.; Sylvester, Paul A.; Russell, Ann; Oliver, Alfred; Morton, Dion; Kennedy, Robin; Jayne, David G.; Huxtable, Richard; Hackett, Roland; Card, Mia; Brown, Julia; Blazeby, Jane M.

    2016-01-01

    Background Colorectal cancer (CRC) is a major cause of worldwide morbidity and mortality. Surgical treatment is common, and there is a great need to improve the delivery of such care. The gold standard for evaluating surgery is within well-designed randomized controlled trials (RCTs); however, the impact of RCTs is diminished by a lack of coordinated outcome measurement and reporting. A solution to these issues is to develop an agreed standard “core” set of outcomes to be measured in all trials to facilitate cross-study comparisons, meta-analysis, and minimize outcome reporting bias. This study defines a core outcome set for CRC surgery. Methods and Findings The scope of this COS includes clinical effectiveness trials of surgical interventions for colorectal cancer. Excluded were nonsurgical oncological interventions. Potential outcomes of importance to patients and professionals were identified through systematic literature reviews and patient interviews. All outcomes were transcribed verbatim and categorized into domains by two independent researchers. This informed a questionnaire survey that asked stakeholders (patients and professionals) from United Kingdom CRC centers to rate the importance of each domain. Respondents were resurveyed following group feedback (Delphi methods). Outcomes rated as less important were discarded after each survey round according to predefined criteria, and remaining outcomes were considered at three consensus meetings; two involving international professionals and a separate one with patients. A modified nominal group technique was used to gain the final consensus. Data sources identified 1,216 outcomes of CRC surgery that informed a 91 domain questionnaire. First round questionnaires were returned from 63 out of 81 (78%) centers, including 90 professionals, and 97 out of 267 (35%) patients. Second round response rates were high for all stakeholders (>80%). Analysis of responses lead to 45 and 23 outcome domains being retained

  5. From the Common Core to the Classroom: A Professional Development Efficacy Study for the Common Core State Standards for Mathematics

    ERIC Educational Resources Information Center

    Rimbey, Kimberly A.

    2013-01-01

    In this mixed-methods study, I examined the relationship between professional development based on the Common Core State Standards for Mathematics and teacher knowledge, classroom practice, and student learning. Participants were randomly assigned to experimental and control groups. The 50-hour professional development treatment was administered…

  6. Secondary Social Studies Teachers' Experiences Implementing Common Core State Literacy Standards: A Phenomenological Study

    ERIC Educational Resources Information Center

    Webb, Krista Faith Huskey

    2014-01-01

    The purpose of this phenomenological study was to examine the experiences of secondary social studies teachers who implemented Common Core State Standards for English Language Arts & Literacy in history/social studies, science and technical subjects in social studies courses requiring End of Course Tests at secondary schools in one suburban…

  7. Monitoring of Western Corn Rootworm Damage in Maize Fields by Using Integrated Radar (ALOS PALSAR) and Optical (IRS LISS, AWiFS) Satellite Data

    NASA Astrophysics Data System (ADS)

    Nador, Gizella; Fenyes, Diana; Surek, Gyorgy; Vasas, Laszlo

    2008-11-01

    The gradual dispersion of western corn rootworm (WCR) is becoming a serious maize pest in Europe, and all over the world. In 2008 using remote sensing data, the Remote Sensing Centre of Institute of Geodesy, Cartography and Remote Sensing (FÖMI RSC) carried out this project to identify WCR larval damage. Our goal with the present project is to assess and identify the disorder and structural changes caused by WCR larvae using optical (IRS-P6 AWiFS, IRS-P6 LISS, SPOT4 and SPOT5) and polarimetic radar (ALOS PALSAR) satellite images. The project aims to identify the extent of WCR damaged cornfields using both polarimetic radar images and optical satellite data time series. Findings were tested against on-the-spot ground assessments. Using radar polarimetry increased the accuracy significantly. The final results have implications for plant protection strategy, farming practices, pesticide producers, state authorities and research institutes.

  8. A Pilot Study for Integrating Volunteers with Core Psychiatry Faculty

    ERIC Educational Resources Information Center

    Dunstone, David

    2005-01-01

    Objective: Among psychiatric educators of medical students and residents are those who are referred to as volunteer faculty. Their unpaid status, limited time to devote to teaching, and isolation from most of the core faculty present us with the challenge of better integrating them with the team of educators. The author describes a faculty…

  9. Soft-core processor study for node-based architectures.

    SciTech Connect

    Van Houten, Jonathan Roger; Jarosz, Jason P.; Welch, Benjamin James; Gallegos, Daniel E.; Learn, Mark Walter

    2008-09-01

    Node-based architecture (NBA) designs for future satellite projects hold the promise of decreasing system development time and costs, size, weight, and power and positioning the laboratory to address other emerging mission opportunities quickly. Reconfigurable Field Programmable Gate Array (FPGA) based modules will comprise the core of several of the NBA nodes. Microprocessing capabilities will be necessary with varying degrees of mission-specific performance requirements on these nodes. To enable the flexibility of these reconfigurable nodes, it is advantageous to incorporate the microprocessor into the FPGA itself, either as a hardcore processor built into the FPGA or as a soft-core processor built out of FPGA elements. This document describes the evaluation of three reconfigurable FPGA based processors for use in future NBA systems--two soft cores (MicroBlaze and non-fault-tolerant LEON) and one hard core (PowerPC 405). Two standard performance benchmark applications were developed for each processor. The first, Dhrystone, is a fixed-point operation metric. The second, Whetstone, is a floating-point operation metric. Several trials were run at varying code locations, loop counts, processor speeds, and cache configurations. FPGA resource utilization was recorded for each configuration. Cache configurations impacted the results greatly; for optimal processor efficiency it is necessary to enable caches on the processors. Processor caches carry a penalty; cache error mitigation is necessary when operating in a radiation environment.

  10. Synthetic studies on lemonomycin: construction of the tetracyclic core.

    PubMed

    Jiménez-Somarribas, Alberto; Williams, Robert M

    2013-09-01

    A substrate-induced stereocontrol strategy was used to gain access to the tetracyclic core of (-)-lemonomycin. An advanced intermediate was prepared from a known substituted tyrosinol through a 16-step sequence, which involved a Pictet-Spengler reaction, a [3+2] dipolar cycloaddition and an enamide hydrogenation. PMID:25083002

  11. Numerical studies of the margin of vortices with decaying cores

    NASA Technical Reports Server (NTRS)

    Liu, G. C.; Ting, L.

    1986-01-01

    The merging of vortices to a single one is a canonical incompressible viscous flow problem. The merging process begins when the core sizes or the vortices are comparable to their distances and ends when the contour lines of constant vorticity lines are circularized around one center. Approximate solutions to this problem are constructed by adapting the asymptotic solutions for distinct vortices. For the early stage of merging, the next-order terms in the asymptotic solutions are added to the leading term. For the later stage of merging, the vorticity distribution is reinitialized by vortices with overlapping core structures guided by the 'rule of merging' and the velocity of the 'vortex centers' are then defined by a minimum principle. To show the accuracy of the approximate solution, it is compared with the finite-difference solution.

  12. The hypotonic infant: case study of central core disease.

    PubMed

    Castrodale, Val

    2003-01-01

    Causes of hypotonia in the newborn can be broadly categorized into two classifications. Hypotonia with a supraspinal origin may be seen with systemic disease, hypoxic ischemic encephalopathy, cerebral malformations, syndromes (for example: Down, Prader-Willi, Lowe, Zellweger, Smith-Lemli-Opitz), and c-spine injury. Disorders of the motor unit that present with hypotonia in the newborn period include SMA, congenital myotonic dystrophy, congenital myasthenia gravis, and congenital myopathies. Central core disease is one of the classic congenital myopathies that can be differentiated based on characteristic histologic findings. Muscle fiber samples from patients with central core disease possess distinct morphology that can be diagnostic. Many infants may not exhibit muscle weakness in the newborn period, although there have been rare cases of profound hypotonia and respiratory failure. Clearly, muscle biopsy is the gold standard and is indicated for any infant with marked hypotonia that is not thought to be supraspinal in origin. PMID:12597091

  13. Core compressor exit stage study. 1: Aerodynamic and mechanical design

    NASA Technical Reports Server (NTRS)

    Burdsall, E. A.; Canal, E., Jr.; Lyons, K. A.

    1979-01-01

    The effect of aspect ratio on the performance of core compressor exit stages was demonstrated using two three stage, highly loaded, core compressors. Aspect ratio was identified as having a strong influence on compressors endwall loss. Both compressors simulated the last three stages of an advanced eight stage core compressor and were designed with the same 0.915 hub/tip ratio, 4.30 kg/sec (9.47 1bm/sec) inlet corrected flow, and 167 m/sec (547 ft/sec) corrected mean wheel speed. The first compressor had an aspect ratio of 0.81 and an overall pressure ratio of 1.357 at a design adiabatic efficiency of 88.3% with an average diffusion factor or 0.529. The aspect ratio of the second compressor was 1.22 with an overall pressure ratio of 1.324 at a design adiabatic efficiency of 88.7% with an average diffusion factor of 0.491.

  14. Feasibility study on nuclear core design for soluble boron free small modular reactor

    SciTech Connect

    Rabir, Mohamad Hairie Hah, Chang Joo; Ju, Cho Sung

    2015-04-29

    A feasibility study on nuclear core design of soluble boron free (SBF) core for small size (150MWth) small modular reactor (SMR) was investigated. The purpose of this study was to design a once through cycle SMR core, where it can be used to supply electricity to a remote isolated area. PWR fuel assembly design with 17×17 arrangement, with 264 fuel rods per assembly was adopted as the basis design. The computer code CASMO-3/MASTER was used for the search of SBF core and fuel assembly analysis for SMR design. A low critical boron concentration (CBC) below 200 ppm core with 4.7 years once through cycle length was achieved using 57 fuel assemblies having 170 cm of active height. Core reactivity controlled using mainly 512 number of 4 wt% and 960 12 wt% Gd rods.

  15. Feasibility study on nuclear core design for soluble boron free small modular reactor

    NASA Astrophysics Data System (ADS)

    Rabir, Mohamad Hairie; Hah, Chang Joo; Ju, Cho Sung

    2015-04-01

    A feasibility study on nuclear core design of soluble boron free (SBF) core for small size (150MWth) small modular reactor (SMR) was investigated. The purpose of this study was to design a once through cycle SMR core, where it can be used to supply electricity to a remote isolated area. PWR fuel assembly design with 17×17 arrangement, with 264 fuel rods per assembly was adopted as the basis design. The computer code CASMO-3/MASTER was used for the search of SBF core and fuel assembly analysis for SMR design. A low critical boron concentration (CBC) below 200 ppm core with 4.7 years once through cycle length was achieved using 57 fuel assemblies having 170 cm of active height. Core reactivity controlled using mainly 512 number of 4 wt% and 960 12 wt% Gd rods.

  16. Social Studies. Levels 7-12. Revised. Secondary Core Curriculum Standards.

    ERIC Educational Resources Information Center

    Utah State Board of Education, Salt Lake City.

    The Utah 1991 revised social studies core curriculum guide specifies standards that must be completed by all students in grades 7-12 in order to meet Utah graduation standards. A review of the K-6 social studies curriculum also is included. The core curriculum is intended to represent ideas, concepts, and skills that provide a basic social studies…

  17. Social Studies Core Curriculum Standards: Grades 7-12. Revised 1991.

    ERIC Educational Resources Information Center

    Utah State Board of Education, Salt Lake City.

    The social studies core curriculum presented in this guide represents those standards of learning that are essential for all grade 7-12 students in the state of Utah. For each secondary social studies course, core standards are established, as well as the objectives that should be used to meet the standards. The following courses are covered for…

  18. Lessons Learned in Conducting a Lottery-Based Study of Core Knowledge Charter Schools

    ERIC Educational Resources Information Center

    White, Thomas G.; Grissmer, David W.; Altenhofen, Shannon; Larson, Jennifer

    2013-01-01

    The authors are presently in the fourth year of a six-year, lottery-based randomized control trial (RCT) studying the effectiveness of nine Colorado charter schools that have implemented Core Knowledge®. Core Knowledge (CK) is a comprehensive K-8 curriculum for language arts, math, science, social studies, visual arts, and music that is intended…

  19. System Study: High-Pressure Core Spray 1998-2014

    SciTech Connect

    Schroeder, John Alton

    2015-12-01

    This report presents an unreliability evaluation of the high-pressure core spray (HPCS) at eight U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCS results.

  20. System Study: High-Pressure Core Spray 1998–2012

    SciTech Connect

    T. E. Wierman

    2013-10-01

    This report presents an unreliability evaluation of the high-pressure core spray (HPCS) at 8 U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2012 for selected components were obtained from the Equipment Performance and Information Exchange (EPIX). The unreliability results are trended for the most recent 10 year period while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCS results.

  1. System Study: Reactor Core Isolation Cooling 1998–2012

    SciTech Connect

    T. E. Wierman

    2013-10-01

    This report presents an unreliability evaluation of the reactor core isolation cooling (RCIC) system at 31 U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2012 for selected components were obtained from the Equipment Performance and Information Exchange (EPIX). The unreliability results are trended for the most recent 10 year period while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing trend was identified in the HPCI results. Statistically significant decreasing trends were identified for RCIC start-only and 8-hour trends.

  2. System Study: Reactor Core Isolation Cooling 1998-2014

    SciTech Connect

    Schroeder, John Alton

    2015-12-01

    This report presents an unreliability evaluation of the reactor core isolation cooling (RCIC) system at 31 U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant trends were identified in the RCIC results.

  3. System Study: High-Pressure Core Spray 1998–2013

    SciTech Connect

    Schroeder, John Alton

    2015-01-31

    This report presents an unreliability evaluation of the high-pressure core spray (HPCS) at eight U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2013 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCS results.

  4. System Study: Reactor Core Isolation Cooling 1998–2013

    SciTech Connect

    Schroeder, John Alton

    2015-01-31

    This report presents an unreliability evaluation of the reactor core isolation cooling (RCIC) system at 31 U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2013 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant trends were identified in the RCIC results.

  5. Conceptual Reactor Design Study of Very High Temperature Reactor (VHTR) with Prismatic-Type Core

    NASA Astrophysics Data System (ADS)

    Nakano, Masaaki; Tsuji, Nobumasa; Tazawa, Yujiro

    The preliminary conceptual design study of prismatic-type Very High Temperature Reactor (VHTR) has been performed with 950°C outlet coolant temperature for higher efficient hydrogen and electricity production. First, the core internals that enable higher outlet temperature are considered in the viewpoint of reduction of core bypass flow. Three-dimensional thermal and hydraulic analyses are carried out and show that the 950°C outlet temperature requires approximately 90% fuel flow fraction and it can be achieved with the installation of the seals in bottom blocks, the coolant tubes in the permanent side reflectors and the core restraint devices. Next, the core and fission product (FP) release analyses are performed. The analysis methods that have been developed for the pin-in-block fuel, one type of prismatic VHTR cores, can be applied to multi-hole fuel, another type of the cores, with some adjustments of the analytical models.

  6. Issues of Sustainable Redevelopment of City Core: A Study of Developed and Developing Countries

    NASA Astrophysics Data System (ADS)

    Munoth, N.; Jain, R. K.; Raheja, G.; Brar, T. S.

    2013-05-01

    The inner city core has undergone maximum misuse and transformation in the absence of building bye laws and regulation, resulting in decay and dilapidated buildings. These city core areas have been places of life, vitality, wealth, power, enlightenment and culture. However these inner city areas have become marginalized in the process of urban growth and has problems related to decay, dwindling economic conditions and dilapidation leading to migration of the population to better and modern areas. This study intends to investigate the impacts of redevelopment within the core area of developed and developing countries, involving environmental, technical, socioeconomic and legal issues that may influence the attainment of sustainable targets for city core redevelopment.

  7. Fluorescence studies of cyanobacterial phycobiliproteins: I. Spectroscopy of allophycocyanin core complexes. II. Spectroscopy of two phycobilisome core insertion mutants

    SciTech Connect

    Maxson, P.

    1988-10-01

    The work described here relates to the mechanisms governing energy transfer in the core polypeptides of the cyanobacterial phycobilisome. Two approaches are represented: measurements were made on isolated core components for which a great deal of structural information is available; and the fluorescence properties were characterized for the whole phycobilisome from two phycobilisome core insertion mutants. 130 refs.

  8. A Study of Core Journals Used by Agricultural and Extension Educators.

    ERIC Educational Resources Information Center

    Radhakrishna, Rama B.

    A research study had three objectives: to identify the core journals in the agricultural and extension education discipline, determine the importance of journals as a medium of scholarly communication in agricultural and extension education, and determine the subject matter areas published in the field's "core" journal, the "Journal of…

  9. Identifying Core Mobile Learning Faculty Competencies Based Integrated Approach: A Delphi Study

    ERIC Educational Resources Information Center

    Elbarbary, Rafik Said

    2015-01-01

    This study is based on the integrated approach as a concept framework to identify, categorize, and rank a key component of mobile learning core competencies for Egyptian faculty members in higher education. The field investigation framework used four rounds Delphi technique to determine the importance rate of each component of core competencies…

  10. Revisiting Traveling Books: Early Literacy, Social Studies, and the Common Core

    ERIC Educational Resources Information Center

    Swain, Holly Hilboldt; Coleman, Julianne

    2015-01-01

    With the development and institution of the Common Core Standards, teachers must be prepared to integrate content areas such as social studies within the language arts curriculum. Teachers following the suggestions of the Common Core Standards should develop practical and meaningful strategies within their classrooms that encourage and support…

  11. Secondary Social Studies Teachers' Time Commitment When Addressing the Common Core State Standards

    ERIC Educational Resources Information Center

    Kenna, Joshua L.; Russell, William Benedict, III

    2015-01-01

    In 2010 the Common Core State Standards (CCSS) were officially released in America for mathematics and English language arts and soon adopted by 45 of the 50 states. However, within the English langue arts domain there were standards intended for secondary social studies teachers under the title, Common Core State Standards for English Language…

  12. Synthesis and microarray-assisted binding studies of core xylose and fucose containing N-glycans.

    PubMed

    Brzezicka, Katarzyna; Echeverria, Begoña; Serna, Sonia; van Diepen, Angela; Hokke, Cornelis H; Reichardt, Niels-Christian

    2015-05-15

    The synthesis of a collection of 33 xylosylated and core-fucosylated N-glycans found only in nonmammalian organisms such as plants and parasitic helminths has been achieved by employing a highly convergent chemo-enzymatic approach. The influence of these core modifications on the interaction with plant lectins, with the human lectin DC-SIGN (Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Nonintegrin), and with serum antibodies from schistosome-infected individuals was studied. Core xylosylation markedly reduced or completely abolished binding to several mannose-binding plant lectins and to DC-SIGN, a C-type lectin receptor present on antigen presenting cells. Employing the synthetic collection of core-fucosylated and core-xylosylated N-glycans in the context of a larger glycan array including structures lacking these core modifications, we were able to dissect core xylose and core fucose specific antiglycan antibody responses in S. mansoni infection sera, and we observed clear and immunologically relevant differences between children and adult groups infected with this parasite. The work presented here suggests that, quite similar to bisecting N-acetylglucosamine, core xylose distorts the conformation of the unsubstituted glycan, with important implications for the immunogenicity and protein binding properties of complex N-glycans.

  13. Cross-calibration of the Landsat-7 ETM+ and Landsat-5 TM with the ResourceSat-1 (IRS-P6) AWiFS and LISS-III sensors

    USGS Publications Warehouse

    Chander, G.; Scaramuzza, P.L.

    2006-01-01

    Increasingly, data from multiple sensors are used to gain a more complete understanding of land surface processes at a variety of scales. The Landsat suite of satellites has collected the longest continuous archive of multispectral data. The ResourceSat-1 Satellite (also called as IRS-P6) was launched into the polar sunsynchronous orbit on Oct 17, 2003. It carries three remote sensing sensors: the High Resolution Linear Imaging Self-Scanner (LISS-IV), Medium Resolution Linear Imaging Self-Scanner (LISS-III), and the Advanced Wide Field Sensor (AWiFS). These three sensors are used together to provide images with different resolution and coverage. To understand the absolute radiometric calibration accuracy of IRS-P6 AWiFS and LISS-III sensors, image pairs from these sensors were compared to the Landsat-5 TM and Landsat-7 ETM+ sensors. The approach involved the calibration of nearly simultaneous surface observations based on image statistics from areas observed simultaneously by the two sensors.

  14. Cross-calibration of the Landsat-7 ETM+ and Landsat-5 TM with the ResourceSat-1 (IRS-P6) AWiFS and LISS-III sensors

    NASA Astrophysics Data System (ADS)

    Chander, Gyanesh; Scaramuzza, Pat L.

    2006-12-01

    Increasingly, data from multiple sensors are used to gain a more complete understanding of land surface processes at a variety of scales. The Landsat suite of satellites has collected the longest continuous archive of multispectral data. The ResourceSat-1 Satellite (also called as IRS-P6) was launched into the polar sun-synchronous orbit on Oct 17, 2003. It carries three remote sensing sensors: the High Resolution Linear Imaging Self-Scanner (LISS-IV), Medium Resolution Linear Imaging Self-Scanner (LISS-III), and the Advanced Wide Field Sensor (AWiFS). These three sensors are used together to provide images with different resolution and coverage. To understand the absolute radiometric calibration accuracy of IRS-P6 AWiFS and LISS-III sensors, image pairs from these sensors were compared to the Landsat-5 TM and Landsat-7 ETM+ sensors. The approach involved the calibration of nearly simultaneous surface observations based on image statistics from areas observed simultaneously by the two sensors.

  15. Reactor pulse repeatability studies at the annular core research reactor

    SciTech Connect

    DePriest, K.R.; Trinh, T.Q.; Luker, S. M.

    2011-07-01

    The Annular Core Research Reactor (ACRR) at Sandia National Laboratories is a water-moderated pool-type reactor designed for testing many types of objects in the pulse and steady-state mode of operations. Personnel at Sandia began working to improve the repeatability of pulse operations for experimenters in the facility. The ACRR has a unique UO{sub 2}-BeO fuel that makes the task of producing repeatable pulses difficult with the current operating procedure. The ACRR produces a significant quantity of photoneutrons through the {sup 9}Be({gamma}, n){sup 8}Be reaction in the fuel elements. The photoneutrons are the result of the gammas produced during fission and in fission product decay, so their production is very much dependent on the reactor power history and changes throughout the day/week of experiments in the facility. Because the photoneutrons interfere with the delayed-critical measurements required for accurate pulse reactivity prediction, a new operating procedure was created. The photoneutron effects at delayed critical are minimized when using the modified procedure. In addition, the pulse element removal time is standardized for all pulse operations with the modified procedure, and this produces less variation in reactivity removal times. (authors)

  16. First-principles study of the influence of different interfaces and core types on the properties of CdSe/CdS core-shell nanocrystals

    PubMed Central

    Kocevski, V.; Rusz, J.; Eriksson, O.; Sarma, D.D.

    2015-01-01

    With the expanding field of nanoengineering and the production of nanocrystals (NCs) with higher quality and tunable size, having reliable theoretical calculations to complement the experimental results is very important. Here we present such a study of CdSe/CdS core-shell NCs using density functional theory, where we focus on dependence of the properties of these NCs on core types and interfaces between the core and the shell, as well as on the core/shell ratio. We show that the density of states and the absorption indices depend rather weakly on the type of interface and core type. We demonstrate that the HOMO wavefunction is mainly localised in the core of the nanocrystal, depending primarily on the core/shell ratio. On the other hand the LUMO wavefunction spreads more into the shell of the nanocrystal, where its confinement in the core is almost the same in each of the studied structural models. Furthermore, we show that the radiative lifetimes decrease with increasing core sizes due to changes in the dipolar overlap integral of the HOMO and LUMO wavefunctions. In addition, the electron-hole Coulomb interaction energies follow a similar pattern as the localisation of the wavefunctions, with the smaller NCs having higher Coulomb interaction energies. PMID:26039582

  17. Experimental study of the mechanical behaviour of pin reinforced foam core sandwich materials under shear load

    NASA Astrophysics Data System (ADS)

    Dimassi, M. A.; Brauner, C.; Herrmann, A. S.

    2016-03-01

    Sandwich structures with a lightweight closed cell hard foam core have the potential to be used in primary structures of commercial aircrafts. Compared to honeycomb core sandwich, the closed cell foam core sandwich overcomes the issue of moisture take up and makes the manufacturing of low priced and highly integrated structures possible. However, lightweight foam core sandwich materials are prone to failure by localised external loads like low velocity impacts. Invisible cracks could grow in the foam core and threaten the integrity of the structure. In order to enhance the out-of-plane properties of foam core sandwich structures and to improve the damage tolerance (DT) dry fibre bundles are inserted in the foam core. The pins are infused with resin and co-cured with the dry fabric face sheets in an out-of-autoclave process. This study presents the results obtained from shear tests following DIN 53294-standard, on flat sandwich panels. All panels were manufactured with pin-reinforcement manufactured with the Tied Foam Core Technology (TFC) developed by Airbus. The effects of pin material (CFRP and GFRP) and pin volume fraction on the shear properties of the sandwich structure and the crack propagation were investigated and compared to a not pinned reference. It has been concluded that the pin volume fraction has a remarkable effect on the shear properties and damage tolerance of the observed structure. Increasing the pin volume fraction makes the effect of crack redirection more obvious and conserves the integrity of the structure after crack occurrence.

  18. Small Angle Neutron-Scattering Studies of the Core Structure of Intact Neurosecretory Vesicles.

    NASA Astrophysics Data System (ADS)

    Krueger, Susan Takacs

    Small angle neutron scattering (SANS) was used to study the state of the dense cores within intact neurosecretory vesicles. These vesicles transport the neurophysin proteins, along with their associated hormones, oxytocin or vasopressin, from the posterior pituitary gland to the bloodstream, where the entire vesicle contents are released. Knowledge of the vesicle core structure is important in developing an understanding of this release mechanism. Since the core constituents exist in a dense state at concentrations which cannot be reproduced (in solution) in the laboratory, a new method was developed to determine the core structure from SANS experiments performed on intact neurosecretory vesicles. These studies were complemented by biochemical assays performed to determine the role, if any, played by phospholipids in the interactions between the core constituents. H_2O/D_2 O ratio in the solvent can be adjusted, using the method of contrast variation, such that the scattering due to the vesicle membranes is minimized, thus emphasizing the scattering originating from the cores. The applicability of this method for examining the interior of biological vesicles was tested by performing an initial study on human red blood cells, which are similar in structure to other biological vesicles. Changes in intermolecular hemoglobin interactions, occurring when the ionic strength of the solvent was varied or when the cells were deoxygenated, were examined. The results agreed with those expected for dense protein solutions, indicating that the method developed was suitable for the study of hemoglobin within the cells. Similar SANS studies were then performed on intact neurosecretory vesicles. The experimental results were inconsistent with model calculations which assumed that the cores consisted of small, densely-packed particles or large, globular aggregates. Although a unique model could not be determined, the data suggest that the core constituents form long aggregates of

  19. Procedures for use of, and drill cores and cuttings available for study at, the Lithologic Core Storage Library, Idaho National Engineering Laboratory, Idaho

    SciTech Connect

    Davis, L.C.; Hannula, S.R.; Bowers, B.

    1997-03-01

    In 1990, the US Geological Survey, in cooperation with the US Department of Energy, Idaho Operations Office, established the Lithologic Core Storage Library at the Idaho National Engineering Laboratory (INEL). The facility was established to consolidate, catalog, and permanently store nonradioactive drill cores and cuttings from investigations of the subsurface conducted at the INEL, and to provide a location for researchers to examine, sample, and test these materials. The facility is open by appointment to researchers for examination, sampling, and testing of cores and cuttings. This report describes the facility and cores and cuttings stored at the facility. Descriptions of cores and cuttings include the well names, well locations, and depth intervals available. Most cores and cuttings stored at the facility were drilled at or near the INEL, on the eastern Snake River Plain; however, two cores drilled on the western Snake River Plain are stored for comparative studies. Basalt, rhyolite, sedimentary interbeds, and surficial sediments compose the majority of cores and cuttings, most of which are continuous from land surface to their total depth. The deepest core stored at the facility was drilled to 5,000 feet below land surface. This report describes procedures and researchers` responsibilities for access to the facility, and examination, sampling, and return of materials.

  20. Study of photodynamic activity of Au@SiO2 core-shell nanoparticles in vitro.

    PubMed

    Meena, K S; Dhanalekshmi, K I; Jayamoorthy, K

    2016-06-01

    Metal-semiconductor core-shell type Au@SiO2 nanoparticles were prepared by Stober's method. They were characterized by absorption, XRD, HR-TEM and EDAX techniques. The resulting modified core-shell nanoparticles shows that the formation of singlet oxygen, which was confirmed by ESR technique. The photohemolysis studies were carried out under two different experimental conditions. It is observed that the photohemolysis increases with concentration as well as light dose. Cell viability of the core-shell nanoparticles against HeLa cell lines were studied by MTT assay method. The outcomes of the present study indicate that, the Au@SiO2 core-shell nanoparticles are extremely stable with a very high photodynamic efficiency under visible light illumination.

  1. Identifying and Tracking Individual Updraft Cores using Cluster Analysis: A TWP-ICE case study

    NASA Astrophysics Data System (ADS)

    Li, X.; Tao, W.; Collis, S. M.; Varble, A.

    2013-12-01

    Cumulus parameterizations in GCMs depend strongly on the vertical velocity structures of convective updraft cores, or plumes. There hasn't been an accurate way of identifying these cores. The majority of previous studies treat the updraft as a single grid column entity, thus missing many intrinsic characteristics, e.g., the size, strength and spatial orientation of an individual core, its life cycle, and the time variations of the entrainment/detrainment rates associated with its life cycle. In this study, we attempt to apply an innovative algorithm based on the centroid-based k-means cluster analysis to improve our understanding of convection and its associated updraft cores. Both 3-D Doppler radar retrievals and cloud-resolving model simulations of a TWP-ICE campaign case during the monsoon period will be used to test and improve this algorithm. This will provide for more in-depth comparisons between CRM simulations and observations that were not possible previously using the traditional piecewise analysis with each updraft column. The first step is to identify the strongest cores (maximum velocity >10 m/s), since they are well defined and produce definite answers when the cluster analysis algorithm is applied. The preliminary results show that the radar retrieved updraft cores are smaller in size and with the maximum velocity located uniformly at higher levels compared with model simulations. Overall, the model simulations produce much stronger cores compared with the radar retrievals. Within the model simulations, the bulk microphysical scheme simulation produces stronger cores than the spectral bin microphysical scheme. Planned researches include using high temporal-resolution simulations to further track the life cycle of individual updraft cores and study their characteristics.

  2. Study of the F ring core at high and low resolutions with Cassini ISS

    NASA Astrophysics Data System (ADS)

    Deau, Estelle

    2014-11-01

    Saturn’s F ring evolution is still a mystery since its discovery by Pioneer 11. This ring is unique by its changing appearance, its spiral shape, its shepherd satellites Prometheus and Pandora, its ephemeral satellites, and its chaotic behavior. We focus here on the brightest and central region of the F ring called the core. Using Voyager data, the core was primarily believed to be one of the four strands of the F ring (Murray et al., 1997, Icarus, vol.129, p.304-316). However, the core is very different from the other stands, because we have demonstrated previously that the core reconnects on itself over 360 degrees, while the strands don't (Charnoz et al. 2005, Science, vol.310, p.1300-1304). Indeed, the strands originate from the core and are connected between themselves in a single feature that is a spiral, as explained in our previous works (Charnoz et al. 2005, Science, vol.310, p.1300-1304, Deau, 2007, PhD thesis University Paris 7 Denis Diderot). Our present study focus on the F ring core. We have established a protocol in (Deau, 2007, PhD thesis University Paris 7 Denis Diderot) to calculate the radial width and the radial local variations of the core using a Gaussian model. We use this method on Cassini ISS data to derive azimuthal profiles of core's radial width and local kicks. Our study shows that the F ring core is very stable on scale of several months, as suggested by the recent chaos theory of Cuzzi et al. (2014, Icarus, vol.232, p.157-175), while the spiral has a much smaller timescale, i.e. the order of a few weeks.

  3. Star formation in Chamaeleon I and III: a molecular line study of the starless core population

    NASA Astrophysics Data System (ADS)

    Tsitali, A. E.; Belloche, A.; Garrod, R. T.; Parise, B.; Menten, K. M.

    2015-03-01

    Context. The Chamaeleon dark molecular clouds are excellent nearby targets for low-mass star formation studies. Even though they belong to the same cloud complex, Cha I and II are actively forming stars while Cha III shows no sign of ongoing star formation. Aims: We aim to determine the driving factors that have led to the very different levels of star formation activity in Cha I and III and examine the dynamical state and possible evolution of the starless cores within them. Methods: Observations were performed in various molecular transitions with the APEX and Mopra telescopes. We examine the kinematics of the starless cores in the clouds through a virial analysis, a search for contraction motions, and velocity gradients. The chemical differences in the two clouds are explored through their fractional molecular abundances, derived from a non-LTE analysis, and comparison to predictions of chemical models. Results: Five cores are gravitationally bound in Cha I and one in Cha III. The so-called infall signature indicating contraction motions is seen toward 8-17 cores in Cha I and 2-5 cores in Cha III, which leads to a range of 13-28% of the cores in Cha I and 10-25% of the cores in Cha III that are contracting and may become prestellar. There is no significant difference in the turbulence level in the two clouds. Future dynamical interactions between the cores will not be dynamically significant in either Cha I or III, but the subregion Cha I North may experience collisions between cores within ~0.7 Myr. Turbulence dissipation in the cores of both clouds is seen in the high-density tracers N2H+ 1-0 and HC3N 10-9 which have lower non-thermal velocity dispersions compared to C17O 2-1, C18O 2-1, and C34S 2-1. Evidence of depletion in the Cha I core interiors is seen in the abundance distributions of the latter three molecules. The median fractional abundance of C18O is lower in Cha III than Cha I by a factor of ~2. The median abundances of most molecules (except

  4. An experimental study of miscible displacements in heterogeneous carbonate cores using X-ray CT

    SciTech Connect

    Hicks, P.J. Jr. ); Narayanan, K.R. ); Deans, H.A. )

    1994-03-01

    Heterogeneous carbonate formations present many difficult problems in understanding flow and oil recovery from such reservoirs. The purpose of this work is to demonstrate the feasibility and limitations of X-ray CT as a method for measuring fluid saturations in three dimensions during floods in heterogeneous carbonate cores. Porosity and residual oil saturation (ROS) distribution measurements were reported previously for these cores and are summarized here. Simple simulation models are tested to see how well they match the experimental results. This method averages on the millimeter scale and has minimal physical effects on the core. The authors studied heterogeneous carbonate cores. Many investigators have used CT for other types of oilfield laboratory experiments, but little work has been published on CT studies in carbonates.

  5. Multifrequency studies of massive cores with complex spatial and kinematic structures

    NASA Astrophysics Data System (ADS)

    Pirogov, L. E.; Shul'ga, V. M.; Zinchenko, I. I.; Zemlyanukha, P. M.; Patoka, A. N.; Tomasson, M.

    2016-10-01

    Five regions of massive-star formation have been observed in various molecular lines in the frequency range˜85-89 GHz. The studied regions comprise dense cores, which host young stellar objects. The physical parameters of the cores are estimated, including the kinetic temperatures (˜20-40 K), the sizes of the emitting regions (˜0.1-0.6 pc), and the virial masses (˜40-500 M ⊙). The column densities and abundances of various molecules are calculated assuming Local Thermodynamical Equilibrium(LTE). The core in 99.982+4.17, which is associated with the weakest IRAS source, is characterized by reduced molecular abundances. The molecular line widths decrease with increasing distance from the core centers ( b). For b ≳ 0.1 pc, the dependences Δ V ( b) are close to power laws (∝ b - p ), where p varies from ~0.2 to ~0.5, depending on the object. In four cores, the asymmetries of the optically thick HCN(1-0) and HCO+(1-0) lines indicates systematicmotions along the line of sight: collapse in two cores and expansion in two others. Approximate estimates of the accretion rates in the collapsing cores indicate that the forming stars have masses exceeding the solar mass.

  6. Nondestructive observation of teeth post core space using optical coherence tomography: a pilot study.

    PubMed

    Minamino, Takuya; Mine, Atsushi; Omiya, Kouta; Matsumoto, Mariko; Nakatani, Hayaki; Iwashita, Taichi; Ohmi, Masato; Awazu, Kunio; Yatani, Hirofumi

    2014-04-01

    Coronal tooth lesions, such as caries, enamel cracking, and composite resin restoration cavities, have been observed by optical coherence tomography (OCT). This pilot study was performed to verify whether OCT could reveal details of root canals filled with resin core build-up. A dual-cure, one-step, self-etch adhesive system-bonding agent (Clearfil Bond SE ONE, Kuraray Noritake Dental) and dual-cure resin composite core material (Clearfil DC Core Automix ONE, Kuraray Noritake Dental) were used according to the manufacturer's instructions in root canals. OCT was performed at three stages of the core build-up: after the post space preparation, after bonding application, and after resin core fabrication. The cementum was removed in the cementum absent group and the root was left untreated in the cementum present group. Bubbles were observed in the resin cores and gaps formed between the resin core and dentin. In the cementum absent group, the internal structure of the root could be visualized clearly compared with the cementum present group. The root internal structure could be observed by OCT and the image became clearer when cementum was removed.

  7. Core competencies for UK occupational health nurses: a Delphi study

    PubMed Central

    Demou, E.; Kiran, S.; Gaffney, M.; Stevenson, M.; Macdonald, E. B.

    2016-01-01

    Background Occupational health nurses (OHNs) play a pivotal role in the delivery of occupational health (OH) services. Specific competency guidance has been developed in a number of countries, including the UK. While it is acknowledged that UK OHN practice has evolved in recent years, there has been no formal research to capture these developments to ensure that training and curricula remain up-to-date and reflect current practice. Aims To identify current priorities among UK OHNs of the competencies required for OH practice. Methods A modified Delphi study undertaken among representative OHN networks in the UK. This formed part of a larger study including UK and international occupational physicians. The study was conducted in two rounds using a questionnaire based on available guidance on training competencies for OH practice, the published literature, expert panel reviews and conference discussions. Results Consensus among OHNs was high with 7 out of the 12 domains scoring 100% in rating. ‘Good clinical care’ was the principal domain ranked most important, followed by ‘general principles of assessment & management of occupational hazards to health’. ‘Research methods’ and ‘teaching & educational supervision’ were considered least important. Conclusions This study has established UK OHNs’ current priorities on the competencies required for OH practice. The timing of this paper is opportune with the formal launch of the Faculty of Occupational Health Nursing planned in 2018 and should inform the development of competency requirements as part of the Faculty’s goals for standard setting in OHN education and training. PMID:27492470

  8. Core Practice Outcomes for Clinical Nurse Specialists: A Revalidation Study.

    PubMed

    Fulton, Janet S; Mayo, Ann M; Walker, Jane A; Urden, Linda D

    2016-01-01

    Measuring outcomes of clinical nurse specialist (CNS) practice is essential for demonstrating accountability. Literature is limited with respect to the scope of reported CNS outcomes. The National Association of Clinical Nurse Specialists' (NACNS) published listing of CNS outcomes could serve as an outcome measurement framework. Revalidation of these outcomes is an important step in creating a structured outcome measurement approach. The purpose of this descriptive study was to assess CNSs' perceptions of the ongoing validity of NACNS published outcomes. A Web-based survey asked participants to describe, for each of 42 outcomes, the frequency of outcome accountability, importance to practice, and frequency of monitoring. Of the 427 surveys returned, 347 (81%) were included in analysis. Findings demonstrated concordance between identified outcomes and actual CNS practice. When job descriptions included the CNS outcomes, more CNSs reported using the outcomes in practice. Both accountability and importance predicted the monitoring of outcomes (p < .001). This study demonstrated the ongoing validity of NACNS outcomes. Nurse educators must ensure that CNS program curricula are based on the NACNS framework and that successful achievement of program outcomes are congruent with the framework. These outcomes have potential for use as a conceptual framework for guiding future CNS outcome investigations and ongoing monitoring systems. Finally, the findings of this study give voice to CNS practice and provide knowledge about expectations for practice outcomes. PMID:27424927

  9. Interstitial water studies on small core samples, Leg 15

    USGS Publications Warehouse

    Sayles, Fred L.; Manheim, Frank T.; Waterman, Lee S.

    1973-01-01

    Analyses of pore fluids from reducing environments demonstrate that reduction of SO4 is accompanied by large increases in alkalinity and strong depletion of Ca and Mg. The data are compatible with a model of replacement of Fe3+ in clay lattices by Mg from the interstitial solutions and the precipitation of pyrite. Depletions of Na in the interstitial solutions are related to Mg losses by a ratio of approximately 1:3. Pore fluids from oxidizing pelagic sediments exhibit little SO4 depletion. Losses of Mg are accompanied by the addition of Ca to the pore solutions on a nearly 1:1 basis. Strong Sr enrichment is also found in these solutions. The magnitude of the Sr increase suggests that considerable carbonate recrystallization has occurred. As part of an extensive interlaboratory and analytical calibration, the effect of squeezing sediment at different temperatures has been studied in depth. Samples of a variety of lithologies have been included. Enrichment of K by as much as 24 percent and depletion of Mg and Ca by up to 7 percent occurs during warming. However, no significant effect upon Cl and SO4 could be detected. The strongest effects are seen in the minor constituents studied. On warming, Sr, Si, and B are enriched as much as 19, 40, and 60 percent, respectively. The size of the observed concentration changes varies with the mineralogy of the sediment, but is significant in all types studied, particularly with regards to Mg and K.

  10. Core and Refueling Design Studies for the Advanced High Temperature Reactor

    SciTech Connect

    Holcomb, David Eugene; Ilas, Dan; Varma, Venugopal Koikal; Cisneros, Anselmo T; Kelly, Ryan P; Gehin, Jess C

    2011-09-01

    The Advanced High Temperature Reactor (AHTR) is a design concept for a central generating station type [3400 MW(t)] fluoride-salt-cooled high-temperature reactor (FHR). The overall goal of the AHTR development program is to demonstrate the technical feasibility of FHRs as low-cost, large-size power producers while maintaining full passive safety. This report presents the current status of ongoing design studies of the core, in-vessel structures, and refueling options for the AHTR. The AHTR design remains at the notional level of maturity as important material, structural, neutronic, and hydraulic issues remain to be addressed. The present design space exploration, however, indicates that reasonable options exist for the AHTR core, primary heat transport path, and fuel cycle provided that materials and systems technologies develop as anticipated. An illustration of the current AHTR core, reactor vessel, and nearby structures is shown in Fig. ES1. The AHTR core design concept is based upon 252 hexagonal, plate fuel assemblies configured to form a roughly cylindrical core. The core has a fueled height of 5.5 m with 25 cm of reflector above and below the core. The fuel assembly hexagons are {approx}45 cm across the flats. Each fuel assembly contains 18 plates that are 23.9 cm wide and 2.55 cm thick. The reactor vessel has an exterior diameter of 10.48 m and a height of 17.7 m. A row of replaceable graphite reflector prismatic blocks surrounds the core radially. A more complete reactor configuration description is provided in Section 2 of this report. The AHTR core design space exploration was performed under a set of constraints. Only low enrichment (<20%) uranium fuel was considered. The coated particle fuel and matrix materials were derived from those being developed and demonstrated under the Department of Energy Office of Nuclear Energy (DOE-NE) advanced gas reactor program. The coated particle volumetric packing fraction was restricted to at most 40%. The pressure

  11. Magnetic studies of erosion in a Scottish lake catchment. 1. Core chronology and correlation

    SciTech Connect

    Appleby, P.G.; Dearing J.A.; Oldfield, F.

    1985-11-01

    Magnetic susceptibility, /sup 210/Pb, /sup 137/Cs, /sup 14/C, and paleomagnetic secular variation are used to establish the chronology of sedimentation in a set of cores from Loch Frisa in western Scotland. The /sup 14/C dates obtained are not compatible with the chronology derived from all the other techniques and this is ascribed to inwash of old particulate carbon from the watershed. Central cores show little evidence of changes in sedimentation rate over the last 150 years whereas marginal cores contain evidence of major increases arising from ploughing and from drainage associated with catchment afforestation since 1935. The results illustrate the value of a multiple core approach to sedimentation and erosion studies even where complex lake morphometry precludes calculation of sediment budgets.

  12. A Global Study of Inner Core Boundary Topography and its Temporal Variations

    NASA Astrophysics Data System (ADS)

    Ibourichene, A.; Romanowicz, B. A.

    2015-12-01

    The inner core boundary (ICB) separates the solid inner core from the surrounding liquid outer core. Its detailed properties, such as its shape, the density jump across it or its topography are key for understanding the dynamics of the core and, ultimately, the generation and sustained character of the Earth's magnetic field. The determination of the ICB topography and its variation with time could also enhance our understanding of the inner core growth and its past history.Seismology makes use of two phases to study the shallow inner core : the PKiKP, reflected at the ICB and the PKIKP, refracted into the inner core. The PKiKP/PKIKP amplitude ratio and the travel time residual of these phases characterize the vicinity of the ICB and may help constrain ICB topography. Different studies propose various wavelengths for this topography: from hundreds of meters to tens of kilometers. Several parameters can affect PKiKP/PKIKP amplitude ratios and the corresponding differential travel time, such as the quality factor of the shallow inner core, the density jump at the ICB, the geometry of the ray paths or even the reflection coefficient at the ICB. We present a global map of PKiKP/PKIKP amplitude ratios and differential travel times filtered in different pass-bands, with regional densification based, in particular, on the relatively short wavelength sampling afforded by large aperture broadband arrays, such as USArray, and discuss their spatial variability and interpretation in terms of ICB topography, as appropriate.We also have assembled a catalog of high quality doublets which provide a reference for the stability of the measurements, and point to possible time variability of the topography.

  13. Cycle 0(CY1991) NLS trade studies and analyses report. Book 1: Structures and core vehicle

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This report (SR-1: Structures, Trades, and Analysis), documents the Core Tankage Trades and analyses performed in support of the National Launch System (NLS) Cycle 0 preliminary design activities. The report covers trades that were conducted on the Vehicle Assembly, Fwd Skirt, LO2 Tank, Intertank, LH2 Tank, and Aft Skirt of the NLS Core Tankage. For each trade study, a two page executive summary and the detail trade study are provided. The trade studies contain study results, recommended changes to the Cycle 0 Baselines, and suggested follow on tasks to be performed during Cycle 1.

  14. Relationship of Core Self-Evaluation (CSE) to Approaches to Student Learning and Studying

    ERIC Educational Resources Information Center

    Starcher, Keith

    2015-01-01

    Insights on the use of the Core Self-Evaluation (CSE) and Study Process Questionnaire (SPQ) instruments are presented. The relationship of students' CSE with their approach to studying and learning is explored. Differences in approach to studying are also analyzed based on several categorical variables.

  15. The paleoclimatic and geochronologic utility of coring red beds and evaporites: a case study from the RKB core (Permian, Kansas, USA)

    NASA Astrophysics Data System (ADS)

    Soreghan, Gerilyn S.; Benison, Kathleen C.; Foster, Tyler M.; Zambito, Jay; Soreghan, Michael J.

    2015-09-01

    Drill core is critical for robust and high-resolution reconstructions of Earth's climate record, as well demonstrated from both marine successions and modern long-lived lake systems. Deep-time climate reconstructions increasingly require core-based data, but some facies, notably red beds and evaporites, have garnered less attention for both paleoclimatic and geochronologic analyses. Here, we highlight studies from the Rebecca K. Bounds (RKB) core, a nearly continuous, >1.6 km drill core extending from the Cretaceous to the Mississippian, recovered from the US Midcontinent by Amoco Production Company in 1988, and serendipitously made available for academic research. Recent research conducted on this core illustrates the potential to recover high-resolution data for geochronologic and climatic reconstructions from both the fine-grained red bed strata, which largely represent paleo-loess deposits, and associated evaporite strata. In this case, availability of core was instrumental for (1) accessing a continuous vertical section that establishes unambiguous superposition key to both magnetostratigraphic and paleoclimatic analyses, and (2) providing pristine sample material from friable, soluble, and/or lithofacies and mineralogical species otherwise poorly preserved in surface exposures. The potential for high-resolution paleoclimatic reconstruction from coring of deep-time loess strata in particular remains severely underutilized.

  16. A study of the structural efficiency of fluted core graphite-epoxy panels

    NASA Technical Reports Server (NTRS)

    Jegley, Dawn C.

    1990-01-01

    The structural efficiency of compression-loaded graphite-epoxy sandwich panels with fluted cores is studied to determine their weight saving potential. Graphite-epoxy equilateral triangular elements are used to construct the fluted cores for the sandwich panels. Two panel configurations are considered. One configuration has two layers of triangular elements in the fluted core and the second configuration has only one layer of triangular elements in the core. An optimization code is used to find the minimum weight design for each panel configuration. Laminate ply orientations are limited to approx. 45, 0, and 90 deg. A constraint on the axial stiffness is included in the design process so the panel will conform to typical constraints for aircraft wing structures. Minimum thickness requirements for each laminate and maximum allowable strains are also included. A comparison is made of the calculated structural efficiency of the fluted core panels to the structural efficiency of aluminum transport aircraft structures and simple blade-stiffened graphite-epoxy panels. Limited experimental results are also included for comparison with the analytical predictions and to identify the critical failure mechanisms of graphite-epoxy fluted-core sandwich panels.

  17. Study on Ultra-Long Life,Small U-Zr Metallic Fuelled Core With Burnable Poison

    SciTech Connect

    Kenji Tsuji; Hiromitsu Inagaki; Akira Nishikawa; Hisato Matsumiya; Yoshiaki Sakashita; Yasuyuki Moriki; Mitsuaki Yamaoka; Norihiko Handa

    2002-07-01

    A conceptual design for a 50 MWe sodium cooled, U-Pu-Zr metallic fuelled, fast reactor core, which aims at a core lifetime of 30 years, has been performed [1]. As for the compensation for a large burn-up reactivity through 30 years, an axially movable reflector, which is located around the core, carries the major part of it and a burnable poison does the rest. This concept has achieved not only a long core lifetime but also a high discharged burn-up. On this study, a conceptual design for a small fast reactor loading U-Zr metallic fuelled core instead of U-Pu-Zr fuelled core has been conducted, based on the original core arrangement of 4S reactor [2]. Within the range of this study including safety requirements, adopting the burnable poison would be effective to construct a core concept that achieves both a long lifetime and a high discharged burn-up. (authors)

  18. High School Teachers' Perspectives on the English Language Arts Common Core State Standards: An Exploratory Study

    ERIC Educational Resources Information Center

    Ajayi, Lasisi

    2016-01-01

    This was an exploratory study that examined high school teachers' perspectives about their early experiences with the English language arts Common Core State Standards. The sources of data for the study included a survey and structured interviews. Twenty-three high school ELA teachers from one unified school district in Southern California…

  19. A Chandra Study of the Image Power Spectra of 41 Cool Core and Non-cool Core Galaxy Clusters

    NASA Astrophysics Data System (ADS)

    Zhang, Chenhao; Xu, Haiguang; Zhu, Zhenghao; Li, Weitian; Hu, Dan; Wang, Jingying; Gu, Junhua; Gu, Liyi; Zhang, Zhongli; Liu, Chengze; Zhu, Jie; Wu, Xiang-Ping

    2016-06-01

    In this work we propose a new diagnostic to segregate cool core (CC) clusters from non-CC (NCC) clusters by studying the two-dimensional power spectra of the X-ray images observed with the Chandra X-ray observatory. Our sample contains 41 members (z=0.01{--}0.54) which are selected from the Chandra archive when a high photon count, an adequate angular resolution, a relatively complete detector coverage, and coincident CC-NCC classifications derived with three traditional diagnostics are simultaneously guaranteed. We find that in the log-log space the derived image power spectra can be well represented by a constant model component at large wavenumbers, while at small wavenumbers a power excess beyond the constant component appears in all clusters, with a clear tendency that the excess is stronger in CC clusters. By introducing a new CC diagnostic parameter, i.e., the power excess index (PEI), we classify the clusters in our sample and compare the results with those obtained with three traditional CC diagnostics. We find that the results agree with each other very well. By calculating the PEI values of the simulated clusters, we find that the new diagnostic works well at redshifts up to 0.5 for intermediately sized and massive clusters with a typical Chandra or XMM-Newton pointing observation. The new CC diagnostic has several advantages over its counterparts, e.g., it is free of the effects of the commonly seen centroid shift of the X-ray halo caused by merger event, and the corresponding calculation is straightforward, almost irrelevant to the complicated spectral analysis.

  20. Effect of bombesin on core temperature in rats: studies involving radiotelemetry.

    PubMed

    Persaud, R A; Coen, C W

    1994-03-21

    The effect of centrally administered bombesin on core temperature was investigated in rats which had been chronically fitted with a cannula in the third cerebral ventricle and with an intraperitoneal temperature-monitoring radiotransmitter. Intracerebroventricularly administered bombesin (0.01, 0.1 or 1 microgram) resulted in hypothermia, the duration and depth of the effect being a function of the dose. The use of telemetry minimized experimental interventions in this study; the results demonstrate that the hypothermic response to bombesin is not dependent upon exposure to a low ambient temperature, food restriction or insulin treatment as suggested by previous studies involving measurement of core temperature by a rectal probe.

  1. Critical look at studies of radionuclide migration in fractured granite cores

    SciTech Connect

    Isherwood, D.; Failor, R.

    1983-05-01

    A series of laboratory experiments studying radionuclide migration were conducted on eleven fractured granite cores from the Climax Stock at the Nevada Test Site. Failor et al (1982) discuss the equipment used, the preparation of the core, the experimental procedure, the data reduction, and the experimental results. They give estimates of the average fracture apertures, retardation values of /sup 85/Sr, /sup 95m/Tc, and /sup 137/Cs relative to /sup 3/H, and the percentage of each radionuclide retained in the core after each run. To determine the effect of fracture fill material and solution composition on radionuclide migration, they studied both natural and artificial fractures using either natural Climax ground water or distilled water. The results are summarized below along with a discussion of the problems inherent in the experiments and suggestions to minimize these problems.

  2. Studies of mixed HEU-LEU-MTR cores using 3D models

    SciTech Connect

    Haenggi, P.; Lehmann, E.; Hammer, J.; Christen, R.

    1997-08-01

    Several different core loadings were assembled at the SAPHIR research reactor in Switzerland combining the available types of MTR-type fuel elements, consisting mainly of both HEU and LEU fuel. Bearing in mind the well known problems which can occur in such configurations (especially power peaking), investigations have been carried out for each new loading with a 2D neutron transport code (BOXER). The axial effects were approximated by a global buckling value and therefore the radial effects could be studied in considerably detail. Some of the results were reported at earlier RERTR meetings and were compared to those obtained by other methods and with experimental values. For the explicit study of the third dimension of the core, another code (SILWER), which has been developed in PSI for LWR power plant cores, has been selected. With the help of an adapted model for the MTR-core of SAPHIR, several important questions have been addressed. Among other aspects, the estimation of the axial contribution to the hot channel factors, the influence of the control rod position and of the Xe-poisoning on the power distribution were studied. Special attention was given to a core position where a new element was assumed placed near a empty, water filled position. The comparison of elements of low and high enrichments at this position was made in terms of the induced power peaks, with explicit consideration of axial effects. The program SILWER has proven to be applicable to MTR-cores for the investigation of axial effects. For routine use as for the support of reactor operation, this 3D code is a good supplement to the standard 2D model.

  3. 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.

  4. Wetland paleoecological study of southwest coastal Louisiana: sediment cores and diatom calibration dataset

    USGS Publications Warehouse

    Smith, Kathryn E. L.; Flocks, James G.; Steyer, Gregory D.; Piazza, Sarai C.

    2015-01-01

    Wetland sediment data were collected in 2009 and 2010 throughout the southwest Louisiana Chenier Plain as part of a pilot study to develop a diatom-based proxy for past wetland water chemistry and the identification of sediment deposits from tropical storms. The complete dataset includes forty-six surface sediment samples and nine sediment cores. The surface sediment samples were collected in fresh, intermediate, and brackish marsh and are located coincident with Coastwide Reference Monitoring System (CRMS) sites. The nine sediment cores were collected at the Rockefeller Wildlife Refuge (RWR) located in Grand Chenier, La.

  5. Self-assembled heterogeneous argon/neon core-shell clusters studied by photoelectron spectroscopy.

    PubMed

    Lundwall, M; Pokapanich, W; Bergersen, H; Lindblad, A; Rander, T; Ohrwall, G; Tchaplyguine, M; Barth, S; Hergenhahn, U; Svensson, S; Björneholm, O

    2007-06-01

    Clusters formed by a coexpansion process of argon and neon have been studied using synchrotron radiation. Electrons from interatomic Coulombic decay as well as ultraviolet and x-ray photoelectron spectroscopy were used to determine the heterogeneous nature of the clusters and the cluster structure. Binary clusters of argon and neon produced by coexpansion are shown to exhibit a core-shell structure placing argon in the core and neon in the outer shells. Furthermore, the authors show that 2 ML of neon on the argon core is sufficient for neon valence band formation resembling the neon solid. For 1 ML of neon the authors observe a bandwidth narrowing to about half of the bulk value.

  6. Studies of pre-Selma Cretaceous core samples from the outcrop area in western Alabama

    USGS Publications Warehouse

    Monroe, Watson Hiner; Bergenback, Richard E.; Sohl, Norman F.; Applin, Esther R.; Leopold, Estella B.; Pakiser, Helen M.; Conant, Louis C.

    1964-01-01

    Quarter-cuts of the cores belonging to the U.S. National Museum have been deposited on indefinite loan with the Alabama Geological Survey at University, Ala., and with the Shell Oil Co. at Jackson, Miss. They are available there for inspection and study.

  7. Motivation to Study Core French: Comparing Recent Immigrants and Canadian-Born Secondary School Students

    ERIC Educational Resources Information Center

    Mady, Callie J.

    2010-01-01

    As the number of Allophone students attending public schools in Canada continues to increase (Statistics Canada, 2008), it is clear that a need exists in English-dominant areas to purposefully address the integration of these students into core French. I report the findings of a mixed-method study that was conducted to assess and compare the…

  8. A Pilot Study of Core Topics in Introductory Social Psychology and Developmental Psychology Textbooks

    ERIC Educational Resources Information Center

    Whitehead, George I., III; Smith, Stephanie H.; Losonczy-Marshall, Marta

    2014-01-01

    This study examined the similarities and differences in the topics and references in selected chapters of eight introductory social psychology textbooks and six developmental psychology textbooks. We wanted to determine the extent to which there were core concepts and references presented in these chapters. We found a relatively small set of core…

  9. Contents of a Core Library in Continuing Medical Education: A Delphi Study

    ERIC Educational Resources Information Center

    Olson, Curtis A.; Tooman, Tricia R.; Leist, James C.

    2005-01-01

    Introduction: In developing their professional competence, those who are interested in the practice of continuing medical education (CME) should recognize the knowledge base that defines their field. This study systematically identifies and organizes a list of books and journals comprising a core library (100 books/15 journals) for CME…

  10. Design Core Commonalities: A Study of the College of Design at Iowa State University

    ERIC Educational Resources Information Center

    Venes, Jane

    2015-01-01

    This comprehensive study asks what a group of rather diverse disciplines have in common. It involves a cross-disciplinary examination of an entire college, the College of Design at Iowa State University. This research was intended to provide a sense of direction in developing and assessing possible core content. The reasoning was that material…

  11. Evaluation of Core Vocabulary Therapy for Deaf Children: Four Treatment Case Studies

    ERIC Educational Resources Information Center

    Herman, Rosalind; Ford, Katie; Thomas, Jane; Oyebade, Natalie; Bennett, Danita; Dodd, Barbara

    2015-01-01

    This study evaluated whether core vocabulary intervention (CVT) improved single word speech accuracy, consistency and intelligibility in four 9-11-year-old children with profound sensori-neural deafness fitted with cochlear implants and/or digital hearing aids. Their speech was characterized by inconsistent production of different error forms for…

  12. Reframing a Social Studies Methods Course: Preparing Elementary Teacher Candidates for the Common Core

    ERIC Educational Resources Information Center

    Gleeson, Ann Marie; D'Souza, Lisa Andries

    2016-01-01

    The emphasis on disciplinary literacy skills embedded within the Common Core State Standards requires a shift in preparing teachers to explicitly address the craft of reading and writing within social studies instruction. As teacher educators, we think it is imperative to understand the ways in which our teacher candidates integrate literacy…

  13. Using the Illinois Core Curriculum for Developing Courses of Study in Vocational Agriculture.

    ERIC Educational Resources Information Center

    Osborne, Ed; Hemp, Paul

    This booklet is designed to serve as a practical guide to assist teachers in using the Illinois Core Curriculum in Agriculture to develop courses of study for local vocational agriculture courses. Provided first is an overview of vocational agriculture programs on the secondary-school level in the state of Illinois. The next section is a guide for…

  14. History as the Core of the Precollege Social Studies Curriculum. A Statement of Policy.

    ERIC Educational Resources Information Center

    Organization of History Teachers, Chicago, IL.

    This policy statement by a national professional association of history teachers from kindergarten through grade 12 begins by pointing out that history currently functions as the core of the social studies curriculum prior to college. This position should be expanded and enhanced as a matter of sound curriculum policy. History alone of the social…

  15. Core Competencies: The Challenge for Graduate Peace and Conflict Studies Education

    ERIC Educational Resources Information Center

    Windmueller, John; Wayne, Ellen Kabcenell; Botes, Johannes

    2009-01-01

    This article uses a case study of the assessment of a graduate program in negotiations and conflict management as a springboard for discussing several critical, but unanswered questions in our field. It raises questions regarding the lack of clear core competencies and expectations regarding curricula at the graduate-level of peace and conflict…

  16. Correction of interstitial water changes in calibration methods applied to XRF core-scanning major elements in long sediment cores: Case study from the South China Sea

    NASA Astrophysics Data System (ADS)

    Chen, Quan; Kissel, Catherine; Govin, Aline; Liu, Zhifei; Xie, Xin

    2016-05-01

    Fast and nondestructive X-ray fluorescence (XRF) core scanning provides high-resolution element data that are widely used in paleoclimate studies. However, various matrix and specimen effects prevent the use of semiquantitative raw XRF core-scanning intensities for robust paleoenvironmental interpretations. We present here a case study of a 50.8 m-long piston Core MD12-3432 retrieved from the northern South China Sea. The absorption effect of interstitial water is identified as the major source of deviations between XRF core-scanning intensities and measured element concentrations. The existing two calibration methods, i.e., normalized median-scaled calibration (NMS) and multivariate log-ratio calibration (MLC), are tested with this sequence after the application of water absorption correction. The results indicate that an improvement is still required to appropriately correct the influence of downcore changes in interstitial water content in the long sediment core. Consequently, we implement a new polynomial water content correction in NMS and MLC methods, referred as NPS and P_MLC calibrations. Results calibrated by these two improved methods indicate that the influence of downcore water content changes is now appropriately corrected. We therefore recommend either of the two methods to be applied for robust paleoenvironmental interpretations of major elements measured by XRF-scanning in long sediment sequences with significant downcore interstitial water content changes.

  17. How suitable are peat cores to study historical deposition of PAHs?

    PubMed

    Thuens, Sabine; Blodau, Christian; Radke, Michael

    2013-04-15

    Ombrotrophic peat bogs are natural archives of atmospheric pollution, their depth profiles can be used to study the deposition chronology of harmful contaminants. Prerequisites for deriving historical deposition rates from the peat archive are that contaminants are persistent and immobile in the peat and that the applied dating technique is accurate. To examine these requirements and the accuracy of peat archives for polycyclic aromatic hydrocarbons (PAHs) 12 peat profiles were sampled in 4 bogs in Ontario, Canada, as well as surface peat in one bog. Additionally we carried out laboratory incubations; no degradation occurred over a 3-year period in these experiments. The standard deviations of PAH concentrations in surface samples and of PAH inventories in whole cores was approximately 30%, and concentrations in surface peat were on average 50% higher in hollows than in hummocks. No indications for mobility of PAHs were observed in peat. Temporal deposition trends inferred from peat cores were generally in agreement with trends derived from a sediment core sampled close by but deposition rates to the sediment were substantially higher. A major source of uncertainty was the rather coarse vertical sampling resolution of 5 cm which introduced substantial uncertainty in the dating of the individual segments. This caused variations of the deposition rates up to 70% per PAH between three replicate cores, and it also impedes the identification of deposition peaks. Overall, we conclude that peat cores are suitable archives for inferring atmospheric deposition trends, but due to their relatively low temporal resolution short-term events may not be identified and the development of sampling methods that allow a higher vertical resolution would greatly improve the performance of the method. The analysis of more than one core per site is suggested to provide a realistic estimate of the historic deposition and total inventories.

  18. How suitable are peat cores to study historical deposition of PAHs?

    PubMed

    Thuens, Sabine; Blodau, Christian; Radke, Michael

    2013-04-15

    Ombrotrophic peat bogs are natural archives of atmospheric pollution, their depth profiles can be used to study the deposition chronology of harmful contaminants. Prerequisites for deriving historical deposition rates from the peat archive are that contaminants are persistent and immobile in the peat and that the applied dating technique is accurate. To examine these requirements and the accuracy of peat archives for polycyclic aromatic hydrocarbons (PAHs) 12 peat profiles were sampled in 4 bogs in Ontario, Canada, as well as surface peat in one bog. Additionally we carried out laboratory incubations; no degradation occurred over a 3-year period in these experiments. The standard deviations of PAH concentrations in surface samples and of PAH inventories in whole cores was approximately 30%, and concentrations in surface peat were on average 50% higher in hollows than in hummocks. No indications for mobility of PAHs were observed in peat. Temporal deposition trends inferred from peat cores were generally in agreement with trends derived from a sediment core sampled close by but deposition rates to the sediment were substantially higher. A major source of uncertainty was the rather coarse vertical sampling resolution of 5 cm which introduced substantial uncertainty in the dating of the individual segments. This caused variations of the deposition rates up to 70% per PAH between three replicate cores, and it also impedes the identification of deposition peaks. Overall, we conclude that peat cores are suitable archives for inferring atmospheric deposition trends, but due to their relatively low temporal resolution short-term events may not be identified and the development of sampling methods that allow a higher vertical resolution would greatly improve the performance of the method. The analysis of more than one core per site is suggested to provide a realistic estimate of the historic deposition and total inventories. PMID:23500826

  19. Cadmium Telluride, Cadmium Telluride/Cadmium Sulfide Core/Shell, and Cadmium Telluride/Cadmium Sulfide/Zinc Sulfide Core/Shell/Shell Quantum Dots Study

    NASA Astrophysics Data System (ADS)

    Yan, Yueran

    aqueous phase can quench CdTe/CdS QDs. Additionally, the stability of the different ligands capped CdTe/CdS QDs was tested by dialysis measurement, the hydrodynamic diameters of CdTe and CdTe/CdS core/shell QDs were measured by dynamic light scattering, and dissolving issue was found when CdTe and CdTe/CdS core/shell QDs were diluted in CHCl3. We have characterized the CdTe core and the CdTe/CdS core/shell QDs by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), small angle X-ray scattering (SAXS), and ICP-OES measurements. We have found that the CdTe core was of a zincblende structure, and the shell was a wurtzite structure. And the CdTe/CdS QDs were core/shell QDs instead of alloying QDs. We have also analyzed the photophysical properties of CdTe and CdTe/CdS core/shell QDs. Time-resolved photoluminescence (PL) measurements showed the emission decay lifetimes in the tens of nanoseconds. Additionally, ultrafast charge carrier relaxation dynamics of the CdTe core and CdTe/CdS core/shell QDs were studied by the femtosecond transient absorption (TA) spectroscopy. The transient absorption spectra of CdTe and CdTe/CdS core/shell QDs showed multiple bleaches, which have been assigned to the 1S3/2(h)-1S(e), 2S3/2(h)-1S(e), and 1P3/2(h)-1P(e) transitions. The spectral shifts of these bleaches after shell deposition have been analyzed in the context of a quasi-type-II carrier distribution in the core/shell samples, and interestingly the red shift was only contributed from the conduction band energy levels shifting to lower energy. In addition, the ultrafast evolution of these bleach features has been examined to extract electron cooling rates in these samples. A fast decay component in the 1S3/2(h)-1S(e) transition of the small CdTe QDs was discovered due to the hole being trapped by the defects on the surface of QD. Further, we have studied the PL quenching process of the air exposed CdTe QDs via the PL decay and transient absorption measurements. Oxygen

  20. Theoretical study of core-loss electron energy-loss spectroscopy at graphene nanoribbon edges.

    PubMed

    Fujita, N; Hasnip, P J; Probert, M I J; Yuan, J

    2015-08-01

    A systematic study of simulated atomic-resolution electronic energy-loss spectroscopy (EELS) for different graphene nanoribbons (GNRs) is presented. The results of ab initio studies of carbon [Formula: see text] core-loss EELS on GNRs with different ribbon edge structures and different hydrogen terminations show that theoretical core-loss EELS can distinguish key structural features at the atomic scale. In addition, the combination of polarized core-loss EELS with symmetry resolved electronic partial density of states calculations can be used to identify the origins of all the primary features in the spectra. For example, the nature of the GNR edge structure (armchair, zigzag, etc) can be identified, along with the degree of hydrogenation. Hence it is possible to use the combination of ab initio calculations with high resolution, high energy transmission core-loss EELS experiments to determine the local atomic arrangement and chemical bonding states (i.e. a structural fingerprint) in GNRs, which is essential for future practical applications of graphene.

  1. Theoretical study of core-loss electron energy-loss spectroscopy at graphene nanoribbon edges

    NASA Astrophysics Data System (ADS)

    Fujita, N.; Hasnip, P. J.; Probert, M. I. J.; Yuan, J.

    2015-08-01

    A systematic study of simulated atomic-resolution electronic energy-loss spectroscopy (EELS) for different graphene nanoribbons (GNRs) is presented. The results of ab initio studies of carbon 1s core-loss EELS on GNRs with different ribbon edge structures and different hydrogen terminations show that theoretical core-loss EELS can distinguish key structural features at the atomic scale. In addition, the combination of polarized core-loss EELS with symmetry resolved electronic partial density of states calculations can be used to identify the origins of all the primary features in the spectra. For example, the nature of the GNR edge structure (armchair, zigzag, etc) can be identified, along with the degree of hydrogenation. Hence it is possible to use the combination of ab initio calculations with high resolution, high energy transmission core-loss EELS experiments to determine the local atomic arrangement and chemical bonding states (i.e. a structural fingerprint) in GNRs, which is essential for future practical applications of graphene.

  2. Study of Hydrothermal Mineralization in 2013 Drill Core from Hawaii Island

    NASA Astrophysics Data System (ADS)

    Lautze, N. C.; Calvin, W. M.; Moore, J.; Haskins, E.; Thomas, D. M.

    2014-12-01

    The Humu'ula Groundwater Research Project (HGRP) drilled a continuously-cored hole to nearly 2 km depth near the Saddle Road between Mauna Loa and Mauna Kea volcanoes on Hawaii Island in March of 2013. Temperatures at the bottom of the hole were unexpectedly high and reached over 100 C. A study is underway to characterize hydrothermal (secondary) mineralization in the core at depths below ~ 1 km. Secondary mineralization can indicate the presence, chemistry, and temperature of hydrothermal fluids, therein helping to characterize a present and/or past geothermal system. To date, the study is two pronged. In collaboration with University Nevada Reno (UNR) we used an Analytical Spectral Devices (ASD) FieldSpec instrument to obtain nearly 800 spectra from core depths spanning 3190 to 5785 feet. This device has a 2 cm contact probe that measures from 0.4 to 2.5 mm, and has been used successfully by UNR to identify depth-associated changes in alteration mineralogy and zoning in drill core from other pilot studies. The spectra indicate that rocks above a depth of ~1 km are only weakly altered. At greater depths to the base of the well, chlorite, possibly with some mica, and zeolites are common. The majority of zeolites are spectrally similar to each other at these wavelengths, however analcime and natrolite are uniquely identified in some sections. Epidote was not observed. The secondary mineral assemblages suggest that the alteration was produced by moderate temperature neutral pH fluids. Here, we used the spectral data as a survey tool to help identify and select over 20 sections of core for sampling and more detailed mineralogical analysis using traditional X-Ray Diffraction (XRD) and petrographic techniques, conducted in collaboration with University of Utah. This presentation will include mineral maps with depth and results of the petrographic analyses.

  3. Image-guided Coring for Large-scale Studies in Molecular Pathology

    PubMed Central

    Montaser-Kouhsari, Laleh; Knoblauch, Nicholas W.; Oh, Eun-Yeong; Baker, Gabrielle; Christensen, Stephen; Hazra, Aditi; Tamimi, Rulla M.

    2016-01-01

    Sampling of formalin-fixed paraffin-embedded (FFPE) tissue blocks is a critical initial step in molecular pathology. Image-guided coring (IGC) is a new method for using digital pathology images to guide tissue block coring for molecular analyses. The goal of our study is to evaluate the use of IGC for both tissue-based and nucleic acid–based projects in molecular pathology. First, we used IGC to construct a tissue microarray (TMA); second, we used IGC for FFPE block sampling followed by RNA extraction; and third, we assessed the correlation between nuclear counts quantitated from the IGC images and RNA yields. We used IGC to construct a TMA containing 198 normal and breast cancer cores. Histopathologic analysis showed high accuracy for obtaining tumor and normal breast tissue. Next, we used IGC to obtain normal and tumor breast samples before RNA extraction. We selected a random subset of tumor and normal samples to perform computational image analysis to quantify nuclear density, and we built regression models to estimate RNA yields from nuclear count, age of the block, and core diameter. Number of nuclei and core diameter were the strongest predictors of RNA yields in both normal and tumor tissue. IGC is an effective method for sampling FFPE tissue blocks for TMA construction and nucleic acid extraction. We identify significant associations between quantitative nuclear counts obtained from IGC images and RNA yields, suggesting that the integration of computational image analysis with IGC may be an effective approach for tumor sampling in large-scale molecular studies. PMID:26186251

  4. Geochemical studies of backfill aggregates, lake sediment cores and the Hueco Bolson Aquifer

    NASA Astrophysics Data System (ADS)

    Thapalia, Anita

    This dissertation comprises of three different researches that focuses on the application of geochemistry from aggregates, lake sediment cores and Hueco Bolson Aquifer. Each study is independent and presented in the publication format. The first chapter is already published and the second chapter is in revision phase. Overall, three studies measure the large scale (field) as well as bench scale (lab) water-rock interactions influenced by the climatic and anthropogenic factors spans from the field of environmental geology to civil engineering. The first chapter of this dissertation addresses the chemical evaluation of coarse aggregates from six different quarries in Texas. The goal of this work is to find out the best geochemical methods for assessing the corrosion potential of coarse aggregates prior to their use in mechanically stabilized earth walls. Electrochemical parameters help to define the corrosion potential of aggregates following two different leaching protocols. Testing the coarse and fine aggregates demonstrate the chemical difference due to size-related kinetic leaching effects. Field fines also show different chemistry than the bulk rock indicating the weathering impact on carbonate rocks. The second chapter investigates zinc (Zn) isotopic signatures from eight lake sediment cores collected both from pristine lakes and those impacted by urban anthropogenic contamination. Zinc from the natural weathering of rocks and anthropogenic atmospheric pollutants are transported to these lakes and the signatures are recorded in the sediments. Isotopic analysis of core samples provides the signature of anthropogenic contamination sources. Dated sediment core and isotopic analysis can identify Zn inputs that are correlated to the landuse and population change of the watersheds. Comparison of isotopic data from both pristine and urban lake sediment core also serves as an analog in other lake sediment cores in the world. The third chapter studies on Hueco Bolson

  5. Design of a Brassica rapa core collection for association mapping studies.

    PubMed

    Zhao, Jianjun; Artemyeva, Anna; Del Carpio, Dunia Pino; Basnet, Ram Kumar; Zhang, Ningwen; Gao, Jie; Li, Fei; Bucher, Johan; Wang, Xiaowu; Visser, Richard G F; Bonnema, Guusje

    2010-11-01

    A Brassica rapa collection of 239 accessions, based on two core collections representing different morphotypes from different geographical origins, is presented and its use for association mapping is illustrated for flowering time. We analyzed phenotypic variation of leaf and seed pod traits, plant architecture, and flowering time using data collected from three field experiments and evaluated the genetic diversity with a set of SSR markers. The Wageningen University and Research Centre (WUR) and the Vavilov Research Institute of Plant Industry (VIR) core collections had similar representations of most morphotypes, as illustrated by the phenotypic and genetic variation within these groups. The analysis of population structure revealed five subgroups in the collection, whereas previous studies of the WUR core collection indicated four subgroups; the fifth group identified consisted mainly of oil accessions from the VIR core collection, winter oils from Pakistan, and a number of other types. A very small group of summer oils is described, that is not related to other oil accessions. A candidate gene approach was chosen for association mapping of flowering time with a BrFLC1 biallelic CAPS marker and a BrFLC2 multiallelic SSR marker. The two markers were significantly associated with flowering time, but their effects were confined to certain morphotypes and (or) alleles. Based on these results, we discuss the optimal design for an association mapping population and the need to fix the heterogeneous accessions to facilitate phenotyping and genotyping.

  6. Hybrid Dendrimers of PPI(core)-PAMAM(shell): A Molecular Dynamics Simulation Study.

    PubMed

    Kavyani, Sajjad; Amjad-Iranagh, Sepideh; Dadvar, Mitra; Modarress, Hamid

    2016-09-15

    The structural properties of hybrid dendrimers PPI(core)-PAMAM(shell) for application in drug delivery are studied by coarse-grained molecular dynamics simulation, and their capacity to encapsulate drug guest molecules such as pyrene is investigated by changing the core (PPI) in the PPI-PAMAM hybrids. For this purpose, a coarse-grained model for PPI dendrimer is developed and is used to predict the structural properties as a function of PPI core size, such as the size of hybrid dendrimers, the depth of water penetration, the extent of back-folding of their chain terminals, the size and distribution of created cavities, and asphericity. The results show that the location of pyrene in the interior structure of the hybrids is independent of PPI core size and the branching chains create a barrier against the penetrating molecules in the shell of PPI. Then, by adding the PAMAM to the surface of PPI, this barrier is removed, and this will enhance the encapsulation capacity of the hybrid.

  7. Comparative study of mechanical properties of direct core build-up materials

    PubMed Central

    Kumar, Girish; Shivrayan, Amit

    2015-01-01

    Background and Objectives: The strength greatly influences the selection of core material because core must withstand forces due to mastication and para-function for many years. This study was conducted to evaluate certain mechanical properties of commonly used materials for direct core build-up, including visible light cured composite, polyacid modified composite, resin modified glass ionomer, high copper amalgam, and silver cermet cement. Materials and Methods: All the materials were manipulated according to the manufacturer's recommendations and standard test specimens were prepared. A universal testing machine at different cross-head speed was used to determine all the four mechanical properties. Mean compressive strength, diametral tensile strength, flexural strength, and elastic modulus with standard deviations were calculated. Multiple comparisons of the materials were also done. Results: Considerable differences in compressive strength, diametral tensile strength, and flexural strength were observed. Visible light cured composite showed relatively high compressive strength, diametral tensile strength, and flexural strength compared with the other tested materials. Amalgam showed the highest value for elastic modulus. Silver cermet showed less value for all the properties except for elastic modulus. Conclusions: Strength is one of the most important criteria for selection of a core material. Stronger materials better resist deformation and fracture provide more equitable stress distribution, greater stability, and greater probability of clinical success. PMID:25684905

  8. Design of a Brassica rapa core collection for association mapping studies.

    PubMed

    Zhao, Jianjun; Artemyeva, Anna; Del Carpio, Dunia Pino; Basnet, Ram Kumar; Zhang, Ningwen; Gao, Jie; Li, Fei; Bucher, Johan; Wang, Xiaowu; Visser, Richard G F; Bonnema, Guusje

    2010-11-01

    A Brassica rapa collection of 239 accessions, based on two core collections representing different morphotypes from different geographical origins, is presented and its use for association mapping is illustrated for flowering time. We analyzed phenotypic variation of leaf and seed pod traits, plant architecture, and flowering time using data collected from three field experiments and evaluated the genetic diversity with a set of SSR markers. The Wageningen University and Research Centre (WUR) and the Vavilov Research Institute of Plant Industry (VIR) core collections had similar representations of most morphotypes, as illustrated by the phenotypic and genetic variation within these groups. The analysis of population structure revealed five subgroups in the collection, whereas previous studies of the WUR core collection indicated four subgroups; the fifth group identified consisted mainly of oil accessions from the VIR core collection, winter oils from Pakistan, and a number of other types. A very small group of summer oils is described, that is not related to other oil accessions. A candidate gene approach was chosen for association mapping of flowering time with a BrFLC1 biallelic CAPS marker and a BrFLC2 multiallelic SSR marker. The two markers were significantly associated with flowering time, but their effects were confined to certain morphotypes and (or) alleles. Based on these results, we discuss the optimal design for an association mapping population and the need to fix the heterogeneous accessions to facilitate phenotyping and genotyping. PMID:21076504

  9. Hybrid Dendrimers of PPI(core)-PAMAM(shell): A Molecular Dynamics Simulation Study.

    PubMed

    Kavyani, Sajjad; Amjad-Iranagh, Sepideh; Dadvar, Mitra; Modarress, Hamid

    2016-09-15

    The structural properties of hybrid dendrimers PPI(core)-PAMAM(shell) for application in drug delivery are studied by coarse-grained molecular dynamics simulation, and their capacity to encapsulate drug guest molecules such as pyrene is investigated by changing the core (PPI) in the PPI-PAMAM hybrids. For this purpose, a coarse-grained model for PPI dendrimer is developed and is used to predict the structural properties as a function of PPI core size, such as the size of hybrid dendrimers, the depth of water penetration, the extent of back-folding of their chain terminals, the size and distribution of created cavities, and asphericity. The results show that the location of pyrene in the interior structure of the hybrids is independent of PPI core size and the branching chains create a barrier against the penetrating molecules in the shell of PPI. Then, by adding the PAMAM to the surface of PPI, this barrier is removed, and this will enhance the encapsulation capacity of the hybrid. PMID:27557447

  10. Numerical study on double-diffusive convection in the Earth's core

    NASA Astrophysics Data System (ADS)

    Trümper, T.; Breuer, M.; Hansen, U.

    2011-12-01

    Our numerical study focuses on convection in a rotating spherical shell with the objective to model combined thermal and compositional convection as proposed for the Earth's core. Since the core is cooling, a thermal gradient is established, which can drive thermal convection. Simultaneously, due to the solidification of the inner core latent heat is released at the freezing front and the concentration of the light constituents of the liquid phase increases thus providing a source for compositional buoyancy. Typically, the molecular diffusivities of both driving components differ by some orders of magnitude. To account for this difference it is indicated to adopt a double-diffusive convection model in treating Earth's core dynamics. As opposed to purely thermal or purely compositional convection the double-diffusive system is controlled by two Rayleigh numbers associated with the respective buoyancy sources. Using the Rayleigh numbers as control parameters neutral curves of the linear onset of convection in the rotating shell are determined for different Ekman numbers and diffusivity ratios. It is found that the neutral curves depend significantly on the system parameters. By comparison with the analytical solutions of the rotating cylindrical annulus it is shown that the neutral curves represent a superposition of curves associated with solutions with different azimuthal wave numbers. Furthermore, fully non-linear simulations are presented in order to elucidate the effect of isochemical and fixed chemical flux boundary conditions on the convection. Both the forcing ratio and the chemical boundary condition have distinct effects on the system that are discussed separately.

  11. Molecular dynamics study of crater formation by core-shell structured cluster impact

    NASA Astrophysics Data System (ADS)

    Aoki, Takaaki; Seki, Toshio; Matsuo, Jiro

    2012-07-01

    Crater formation processes by the impacts of large clusters with binary atomic species were studied using molecular dynamics (MD) simulations. Argon and xenon atoms are artificially organized in core-shell cluster structures with various component ratios and irradiated on a Si(1 0 0) target surface. When the cluster has Xe1000 core covered with 1000 Ar atoms, and impacts at a total of 20 keV, the core Xe cluster penetrates into the deep area, and a crater with a conical shape is left on the target. On the other hand, in the case of a cluster with the opposite structure, Ar1000 core covered with 1000 Xe atoms, the cluster stops at a shallow area of the target. The incident cluster atoms are mixed and tend to spread in a lateral direction, which results in a square shaped crater with a shallower hole and wider opening. The MD simulations suggest that large cluster impacts cause different irradiation effects by changing the structure, even if the component ratio is the same.

  12. Tephra studies on the deep Talos Dome ice core, East Antarctic Plateau

    NASA Astrophysics Data System (ADS)

    Narcisi, B.; Petit, J.; Delmonte, B.; Stenni, B.

    2011-12-01

    In the context of the TALDICE (TALos Dome Ice CorE) project conducted by a consortium of five European nations led by Italy, a 1620-m long ice core has been drilled at Talos Dome (72°49'S, 159°11'E; 2315 m; www.taldice.org), on the eastern edge of the East Antarctic plateau during the field seasons 2004-2008. Owing to its relatively high accumulation rate, this near-coastal core preserves a detailed undisturbed paleoclimate record covering the past 250,000 years, back to Marine Isotope Stage (MIS) 7.5. The Talos Dome ice is a significant volcanic ash archive. During core inspection of the TALDICE core, more than 100 macroscopic tephra layers were located and inventoried, with an average tephra frequency one order of magnitude greater than the tephra frequency in deep cores from inland East Antarctic plateau over the last two glacial cycles. TALDICE prominent tephra layers, studied by scanning electron microscopy, Coulter Counter and electron microprobe analysis, display an alkaline geochemical character indicating an origin in nearby volcanoes of the Melbourne Volcanic Province (McMurdo Volcanic Group). Our tephra record helps reconstruct an improved history of explosive eruptions in northern Victoria Land, supplementing the stratigraphic record obtained by outcrop studies and documenting previously unknown temporal trends and specific episodes. Investigations on less prominent tephra horizons are in progress with the aim of complementing the Holocene volcanic record of local visible beds and establishing the detailed tephrostratigraphy for the region. To date about ten discrete ice sections showing anomalously coarse grain size has proved to contain significant concentrations of unreworked volcanic glass. Single shard major element analyses of some invisible volcanic horizons indicate subalkaline compositions, which are incompatible with Antarctic volcanism and suggesting long-distance tephra transport from either South American and/or New Zealand volcanoes

  13. Influence of Different Post-Core Systems on Impact Stress: a Pilot Study

    PubMed Central

    Kondoh, Yoshihiro; Takeda, Tomotaka; Ozawa, Takamitsu; Narimatsu, Keishiro; Konno, Michiyo; Fujii, Toshiki; Sekiguchi, Chieko; Nakajima, Kazunori; Ishigami, Keiichi; Shomura, Masahito

    2013-01-01

    This pilot study compared impact strain at the core and root surfaces between two different post-core systems. Materials and Methods: The form of a bovine mandibular front tooth was modified to resemble that of a human maxillary incisor as a test specimen. A cast post and core (Metal PC) and composite resin and glass fiber-reinforced epoxy resin post (Fiber-Resin PC) system were tested. Four gauges were affixed to the buccal and lingual surfaces of the core and root. The specimens were then embedded in a metal mold using dental stone. A pendulum-type device with a pyramid-shaped metal impact object with a titanium alloy head was used to provide 2 different shock forces. Maximum distortion was measured and analyzed. Results: Distortion at the core at each measurement point and total amount of distortion with Fiber-Resin PC was significantly greater (p<0.05) than that with Metal PC against both impact forces. On the other hand, distortion at the root at the buccal measurement point with Fiber-Resin PC was significantly less than that with Metal PC against both impact forces. Total distortion was significantly less with Fiber-Resin PC than that with Metal PC against the greater impact shock. Acceleration with Fiber-Resin PC was significantly less than that with Metal PC against both impact forces. Conclusion: Fiber-Resin PC has the potential to protect remaining root against traumatic force. This suggests that a Fiber-Resin PC is more suitable for non-vital teeth against not only occlusal but also traumatic impact force. PMID:24358064

  14. Generic BWR-4 degraded core in-vessel study. Status report

    SciTech Connect

    Not Available

    1984-11-01

    Original intent of this project was to produce a phenomenological study of the in-vessel degradation which occurs during the TQUX and TQUV sequences for a generic BWR-4 from the initiation of the FSAR Chapter 15 operational transient through core debris bed formation to the failure of the primary pressure boundary. Bounding calculations were to be performed for the two high pressure and low pressure non-LOCA scenarios to assess the uncertainties in the current state of knowledge regarding the source terms for containment integrity studies. Source terms as such were defined in terms of hydrogen generation, unreacted metal, and coolant inventroy, and in terms of the form, sequencing and mode of dispersal through the primary vessel boundary. Fission product release was not to be considered as part of this study. Premature termination of the project, however, led to the dicontinuation of work on an as is basis. Work on the in-core phase from the point of scram to core debris bed formation was largely completed. A preliminary scoping calculation on the debris bed phase had been initiated. This report documents the status of the study at termination.

  15. A study of the earth's free core nutation using international deployment of accelerometers gravity data

    NASA Technical Reports Server (NTRS)

    Cummins, Phil R.; Wahr, John M.

    1993-01-01

    In this study we consider the influence of the earth's free core nutation (FCN) on diurnal tidal admittance estimates for 11 stations of the globally distributed International Deployment of Accelerometers network. The FCN causes a resonant enhancement of the diurnal admittances which can be used to estimate some properties of the FCN. Estimations of the parameters describing the FCN (period, Q, and resonance strength) are made using data from individual stations and many stations simultaneously. These yield a result for the period of 423-452 sidereal days, which is shorter than theory predicts but is in agreement with many previous studies and suggests that the dynamical ellipticity of the core may be greater than its hydrostatic value.

  16. Studies on beef heart ubiquinol-cytochrome c reductase. Topological studies on the core proteins using proteolytic digestion and immunoreplication.

    PubMed

    Mendel-Hartvig, I; Nelson, B D

    1983-02-01

    The topology of beef heart Complex III has been studied by tryptic and chymotryptic digestion of isolated Complex III, Mg2+-ATP submitochondrial particles, and mitoplasts. Degradation products were detected by the immunoreplication technique using specific antibodies against core protein 1 (50 K) and core protein 2 (47 K). It can be shown that both peptides are digested from the matrix side of the inner membrane. However, no evidence was found that these peptides were digested by trypsin or chymotrypsin from the cytoplasmic side. It is concluded that the beef heart core proteins are membrane-bound peptides containing tryptic and chymotryptic digestion sites only on the matrix surface of the inner membrane. The data also suggest that beef heart core protein 2 contains multiple domains which are inserted into the membrane from the matrix surface. Proteolytic treatment of submitochondrial particles under conditions which digested at least 50% of the core proteins from the matrix surface did not, however, influence NADH oxidation rates or the respiratory control ratios.

  17. Study of hard core repulsive interactions in an hadronic gas from a comparison with lattice QCD

    NASA Astrophysics Data System (ADS)

    Alba, P.; Vovchenko, V.; Stoecker, H.

    2016-08-01

    We study the influence of hard-core repulsive interactions within the Hadron- Resonace Gas model in comparison to first principle calculation performed on a lattice. We check the effect of a bag-like parametrization for particle eigenvolume on flavor correlators, looking for an extension of the agreement with lattice simulations up to higher temperatures, as was yet pointed out in an analysis of hadron yields measured by the ALICE experiment. Hints for a flavor depending eigenvolume are present.

  18. The Common Core State Standards and the Role of Instructional Materials: A Case Study on EdReports.org

    ERIC Educational Resources Information Center

    Watt, Michael G.

    2016-01-01

    The purpose of this study was to review research studies investigating the role of instructional materials in relation to the Common Core State Standards and to evaluate whether a new organisation, EdReports.org, founded to evaluate the alignment of instructional materials to the Common Core State Standards, has achieved its objectives. Content…

  19. Human LDL core cholesterol ester packing: three-dimensional image reconstruction and SAXS simulation studies

    PubMed Central

    Liu, Yuhang; Luo, Dong; Atkinson, David

    2011-01-01

    Human LDL undergoes a reversible thermal order-disorder phase transition associated with the cholesterol ester packing in the lipid core. Structural changes associated with this phase transition have been shown to affect the resistance of LDL to oxidation in vitro studies. Previous electron cryo-microscopy studies have provided image evidence that the cholesterol ester is packed in three flat layers in the core at temperatures below the phase transition. To study changes in lipid packing, overall structure and particle morphology in three dimensions (3D) subsequent to the phase transition, we cryo-preserved human LDL at a temperature above phase transition (53°C) and examined the sample by electron microscopy and image reconstruction. The LDL frozen from 53°C adopted a different morphology. The central density layer was disrupted and the outer two layers formed a “disrupted shell”-shaped density, located concentrically underneath the surface density of the LDL particle. Simulation of the small angle X-ray scattering curves and comparison with published data suggested that this disrupted shell organization represents an intermediate state in the transition from isotropic to layered packing of the lipid. Thus, the results revealed, with 3D images, the lipid packing in the dynamic process of the LDL lipid-core phase transition. PMID:21047995

  20. Constraints on Core Formation From Systematic Study of Temperature Effect on Metal- Silicate Partitioning

    NASA Astrophysics Data System (ADS)

    Siebert, J.; Ryerson, F.; Watson, H.

    2007-12-01

    Models of core formation are currently established through metal-silicate partitioning results at high pressure and high temperature. Although a large effect of temperature on metal-silicate equilibrium is expected on thermodynamic grounds, very little experimental work has been dedicated to separate this effect from pressure and provide a systematic study of partitioning coefficients across a wide range of temperatures. Utilizing free energy of pure oxides formation data at atmospheric pressure to predict the temperature effect on metal-silicate partitioning might be a source of large uncertainties for some recent core formation models [1, 2]. The present study is aimed at constraining the temperature dependence of partition coefficients for a large number of elements and extending the existing database to extreme temperatures. Using a new piston-cylinder design assembly [3] allows us to determine a suite of isobaric partitioning experiments at 3 GPa within a temperature range from 1600 to 2700°C. Systematic partitioning behaviors between molten metal and peridotite or basaltic melts of elements normally regarded as moderately siderophile, slightly siderophile and refractory lithophile are presented. These include Ni, Co, W, Mo, Cr, Mn, V, P, Ga as well as elements that are usually poorly integrated with any accretion or core formation models (Ge, Nb, Ta, Te, Zn). Absolute measurements of partitioning coefficients combining EMP and LA-ICPMS analytical methods are provided. The individual effects of oxygen fugacity and pressure have also been studied through piston cylinder experiments (2200°C, 3 GPa) between IW- 1.5 to IW-4 and multi-anvil experiments to 15 GPa. These partitioning results are then combined with literature data to refine our understanding of core formation and place constraints on the highly debated Earth's accretion mechanism issue. [1] Wade and Wood, EPSL, 2005. [2] Corgne et al., GCA, in press. [3] Cottrell and Walker, GCA, 2006.

  1. Comprehensive assessment of radiation dose estimates for the CORE320 study.

    PubMed

    Rybicki, Frank J; Mather, Richard T; Kumamaru, Kanako K; Brinker, Jeffrey; Chen, Marcus Y; Cox, Christopher; Matheson, Matthew B; Dewey, Marc; DiCarli, Marcelo F; Miller, Julie M; Geleijns, Jacob; George, Richard T; Paul, Narinder; Texter, John; Vavere, Andrea; Yaw, Tan Swee; Lima, Joao A C; Clouse, Melvin E

    2015-01-01

    OBJECTIVE. The purpose of this study was to comprehensively study estimated radiation doses for subjects included in the main analysis of the Combined Non-invasive Coronary Angiography and Myocardial Perfusion Imaging Using 320 Detector Computed Tomography (CORE320) study ( ClinicalTrials.gov identifier NCT00934037), a clinical trial comparing combined CT angiography (CTA) and perfusion CT with the reference standard catheter angiography plus myocardial perfusion SPECT. SUBJECTS AND METHODS. Prospectively acquired data on 381 CORE320 subjects were analyzed in four groups of testing related to radiation exposure. Radiation dose estimates were compared between modalities for combined CTA and perfusion CT with respect to covariates known to influence radiation exposure and for the main clinical outcomes defined by the trial. The final analysis assessed variations in radiation dose with respect to several factors inherent to the trial. RESULTS. The mean radiation dose estimate for the combined CTA and perfusion CT protocol (8.63 mSv) was significantly (p < 0.0001 for both) less than the average dose delivered from SPECT (10.48 mSv) and the average dose from diagnostic catheter angiography (11.63 mSv). There was no significant difference in estimated CTA-perfusion CT radiation dose for subjects who had false-positive or false-negative results in the CORE320 main analyses in a comparison with subjects for whom the CTA-perfusion CT findings were in accordance with the reference standard SPECT plus catheter angiographic findings. CONCLUSION. Radiation dose estimates from CORE320 support clinical implementation of a combined CT protocol for assessing coronary anatomy and myocardial perfusion. PMID:25539270

  2. Core competencies for health professionals' training in pediatric behavioral sleep care: a Delphi study.

    PubMed

    Boerner, Katelynn E; Coulombe, J Aimée; Corkum, Penny

    2015-01-01

    The need to train non-sleep-specialist health professionals in evidence-based pediatric behavioral sleep care is well established. The objective of the present study was to develop a list of core competencies for training health professionals in assisting families of 1- to 10-year old children with behavioral insomnia of childhood. A modified Delphi methodology was employed, involving iterative rounds of surveys that were administered to 46 experts to obtain consensus on a core competency list. The final list captured areas relevant to the identification and treatment of pediatric behavioral sleep problems. This work has the potential to contribute to the development of training materials to prepare non-sleep-specialist health professionals to identify and treat pediatric behavioral sleep problems, ideally within stepped-care frameworks.

  3. FDTD study of the formation of optical vortices associated with core-shell nanoparticle cluster

    NASA Astrophysics Data System (ADS)

    Rahman, Md Mahfuzur; Lu, Jin You; Ni, George; Fang, Nicholas Xuanlai; Zhang, Tiejun; Ghaferi, Amal Al

    2015-03-01

    Light absorbing plasmonic metal-dielectric nanoparticles suspended in water, or nanofluids have recently been experimentally demonstrated to produce steam at high efficiencies upon solar illumination. This approach localizes high temperatures to the interior of the liquid through efficient trapping of incoming light via scattering and absorption mechanisms. In suspensions, nanoparticles may form clusters due to surface wetting properties, and little work has focused on understanding the optical properties of clusters. In this work, we use the FDTD method to accurately visualize the optical power flow through various plasmonic metal-silica core-shell nanoparticle pairs at different inter-particle separations (10-100 nm). At these separations phase singularities of the power flow can occur, such as vortices of light inside the dielectric core which can enhance the absorption cross-section of the cluster. We study the conditions required to form these vortices. We also consider titanium nitride as shell, other than the widely studied noble metals to visualize the extinction cross-section of a cluster which depends on the separation, and the permittivity of the dielectric core. The authors would like to acknowledge the valuable support from Masdar Institute and Massachusetts Institute of Technology for the soler thermal project grant.

  4. Conceptual studies for pressurised water reactor cores employing plutonium erbium zirconium oxide inert matrix fuel assemblies

    NASA Astrophysics Data System (ADS)

    Stanculescu, A.; Kasemeyer, U.; Paratte, J.-M.; Chawla, R.

    1999-08-01

    The most efficient way to enhance plutonium consumption in light water reactors is to eliminate the production of plutonium all together. This requirement leads to fuel concepts in which the uranium is replaced by an inert matrix. At PSI, studies have focused on employing ZrO 2 as inert matrix. Adding a burnable poison to such a fuel proves to be necessary. As a result of scoping studies, Er 2O 3 was identified as the most suitable burnable poison material. The results of whole-core three-dimensional neutronics analyses indicated, for a present-day 1000 MW e pressurised water reactor (PWR), the feasibility of an asymptotic equilibrium four-batch cycle fuelled solely with the proposed PuO 2-Er 2O 3-ZrO 2 inert matrix fuel (IMF). The present paper presents the results of more recent investigations related to `real-life' situations, which call for transition configurations in which mixed IMF and UO 2 assembly loadings must be considered. To determine the influence of the introduction of IMF assemblies on the characteristics of a UO 2-fuelled core, three-dimensional full-core calculations have been performed for a present-day 1000 MW e PWR containing up to 12 optimised IMF assemblies.

  5. A Study of the Access to the Scholarly Record from a Hospital Health Science Core Collection *

    PubMed Central

    Williams, James F.; Pings, Vern M.

    1973-01-01

    This study is an effort to determine possible service performance levels in hospital libraries based on access to the scholarly record of medicine through selected lists of clinical journals and indexing and abstracting journals. The study was designed to test a methodology as well as to provide data for planning and management decisions for health science libraries. Findings and conclusions cover the value of a core collection of journals, length of journal files, performance of certain bibliographic instruments in citation verification, and the implications of study data for library planning and management. PMID:4744345

  6. N Reactor core heatup sensitivity study for the 32-inch unit cell model

    SciTech Connect

    Martin, F.; Zimmerman, B.; Heard, F.

    1988-02-01

    A number of N Reactor core heatup studies have been performed using the TRUMP-BD computer code. These studies were performed to address questions concerning the dependency of results on potential variations in the material properties and/or modeling assumptions. This report described and documents a series of 31 TRUMP-BD runs that were performed to determine the sensitivity of calculated inner-fuel temperatures to a variety of TRUMP input parameters and also to a change in the node density in a high-temperature-gradient region. The results of this study are based on the 32-in. model. 18 refs., 17 figs., 2 tab.

  7. Magnetic Braking, Ambipolar Diffusion, and the Formation of Cloud Cores and Protostars. II. A Parameter Study

    NASA Astrophysics Data System (ADS)

    Basu, Shantanu; Mouschovias, Telemachos Ch.

    1995-10-01

    The formulation of the problem of the formation of protostellar cores in self-gravitating, magnetically supported, rotating, isothermal model molecular clouds was presented in a previous paper, where detailed numerical simulations for two different model clouds were also discussed. In this paper, we study the effect of varying five dimensionless free parameters: the ratio ˜p of external density and central density in a reference state (which is related simply to an initial equilibrium state), the initial radial length scale l˜ref of the column density of the cloud, the central angular velocity of the reference state ˜Ωc,ref, the central neutral-ion collision time in the reference state ˜τni,ref (which is inversely proportional to the collapse retardation factor Vff ≡ τff/τni) and the exponent k in the relation between the ion and neutral densities ni ∝ nkn. In addition to the models previously presented, seven more models are investigated here. Different values (1/1000 to 1/100) of the initial magnetic-braking efficiency parameter ˜p(>0) do not significantly affect the evolution; magnetic braking remains effective during the quasistatic phase and ineffective during the (dynamic) collapse of the magnetically and thermally supercritical core. The initially very effective magnetic braking also means that the solution is insensitive to values of ˜Ωc,ref. Different values of l˜ref yield qualitatively similar evolution, with smaller cloud sizes leading to slightly smaller core sizes. Increasing the value of τni,ref leads to a more rapid evolution and larger, more rapidly rotating cores. A smaller k leads to relatively more rapid evolution in the core and a better core-envelope separation. We also give an analytical explanation of the previously presented result, that the gravitational field acting on an infalling mass shell in the central region of a nonhomologously contracting thin disk increases as 1/r3m, where rm is the Lagrangian radius of the shell.

  8. Studying the Nearest Non-Cool Core Galaxy Cluster with XMM-Newton and Suzaku

    NASA Astrophysics Data System (ADS)

    Wong, Ka-Wah

    X-ray studies of the most nearby galaxy clusters have proved to provide new insights and surprising results compared to studying their more distant counterparts. On small scales within the central ~50 kpc region, the thermodynamic and abundance structures of hot gas within clusters have been mapped to a spatial resolution of a few kpc for the nearest galaxy clusters (e.g., Virgo and Fornax) with high spatial resolution X-ray telescopes such as Chandra or XMM-Newton. The results of these high resolution studies challenge the current picture of the metal enrichment processes in the intracluster medium (ICM), suggesting that the ICM in the central region is primarily enriched by core-collapse supernovae instead of Type Ia supernovae. On a large scale, a few nearby clusters (e.g., Perseus and Virgo) have been mapped with mosaic Suzaku pointings out to their virial radii of Mpc order (or degrees order in angular scale). These results indicate that cluster outskirts are not that simple: near the virial radius, the surface brightness of the ICM is higher and the measured entropy is lower than predictions by self-similar models. These suggest that the ICM in the outer region may be clumpy or that collisional equilibrium may not be achieved due to its very low density. Antlia is the third nearest galaxy cluster that was highly ignored in X-ray in the sky. It is also the nearest non-cool core cluster with a similar low temperature as the cool core Virgo Cluster, allowing us to make a direct comparison to the cool core counterpart in our neighborhood. We request NASA ADAP support for our comprehensive program to study the Antlia Cluster in detail with our recently approved 180 ks XMM-Newton (AO- 11) and 204 ks Suzaku (AO-07) observations, together with the existing XMM-Newton, Suzaku, and ROSAT data in the archive. With our deep XMM-Newton data, we will determine the thermodynamic structures (e.g., density, temperature, entropy, etc) in a scale of few kpc. We will also

  9. Initial experience with a novel EUS-guided core biopsy needle (SharkCore): results of a large North American multicenter study

    PubMed Central

    DiMaio, Christopher J.; Kolb, Jennifer M.; Benias, Petros C.; Shah, Hiral; Shah, Shashin; Haluszka, Oleh; Maranki, Jennifer; Sharzehi, Kaveh; Lam, Eric; Gordon, Stuart R.; Hyder, Sarah M.; Kaimakliotis, Pavlos Z.; Allaparthi, Satya B.; Gress, Frank G.; Sethi, Amrita; Shah, Ashish R.; Nieto, Jose; Kaul, Vivek; Kothari, Shivangi; Kothari, Truptesh H.; Ho, Sammy; Izzy, Manhal J.; Sharma, Neil R.; Watson, Rabindra R.; Muthusamy, V. Raman; Pleskow, Douglas K.; Berzin, Tyler M.; Sawhney, Mandeep; Aljahdi, Emad; Ryou, Marvin; Wong, Clarence K.; Gupta, Parantap; Yang, Dennis; Gonzalez, Susana; Adler, Douglas G.

    2016-01-01

    Background and aims: The ability to safely and effectively obtain sufficient tissue for pathologic evaluation by using endoscopic ultrasound (EUS) guidance remains a challenge. Novel designs in EUS needles may provide for improved ability to obtain such core biopsies. The aim of this study was to evaluate the diagnostic yield of core biopsy specimens obtained using a novel EUS needle specifically designed to obtain core biopsies. Patients and methods: Multicenter retrospective review of all EUS-guided fine-needle biopsies obtained using a novel biopsy needle (SharkCore FNB needle, Medtronic, Dublin, Ireland). Data regarding patient demographics, lesion type/location, technical parameters, and diagnostic yield was obtained. Results: A total of 250 lesions were biopsied in 226 patients (Median age 66 years; 113 (50 %) male). Median size of all lesions (mm): 26 (2 – 150). Overall, a cytologic diagnosis was rendered in 81 % specimens with a median number of 3 passes. When rapid onsite cytologic evaluation (ROSE) was used, cytologic diagnostic yield was 126/149 (85 %) with a median number of 3 passes; without ROSE, cytologic diagnostic yield was 31/45 (69 %, P = 0.03) with a median number of 3 passes. Overall, a pathologic diagnosis was rendered in 130/147 (88 %) specimens with a median number of 2 passes. Pathologic diagnostic yield for specific lesion types: pancreas 70/81 (86 %), subepithelial lesion 13/15 (87 %), lymph node 26/28 (93 %). Ten patients (10/226, 4 %) experienced adverse events: 4 acute pancreatitis, 5 pain, 1 fever/cholangitis. Conclusions: Initial experience with a novel EUS core biopsy needle demonstrates excellent pathologic diagnostic yield with a minimum number of passes.

  10. Initial experience with a novel EUS-guided core biopsy needle (SharkCore): results of a large North American multicenter study

    PubMed Central

    DiMaio, Christopher J.; Kolb, Jennifer M.; Benias, Petros C.; Shah, Hiral; Shah, Shashin; Haluszka, Oleh; Maranki, Jennifer; Sharzehi, Kaveh; Lam, Eric; Gordon, Stuart R.; Hyder, Sarah M.; Kaimakliotis, Pavlos Z.; Allaparthi, Satya B.; Gress, Frank G.; Sethi, Amrita; Shah, Ashish R.; Nieto, Jose; Kaul, Vivek; Kothari, Shivangi; Kothari, Truptesh H.; Ho, Sammy; Izzy, Manhal J.; Sharma, Neil R.; Watson, Rabindra R.; Muthusamy, V. Raman; Pleskow, Douglas K.; Berzin, Tyler M.; Sawhney, Mandeep; Aljahdi, Emad; Ryou, Marvin; Wong, Clarence K.; Gupta, Parantap; Yang, Dennis; Gonzalez, Susana; Adler, Douglas G.

    2016-01-01

    Background and aims: The ability to safely and effectively obtain sufficient tissue for pathologic evaluation by using endoscopic ultrasound (EUS) guidance remains a challenge. Novel designs in EUS needles may provide for improved ability to obtain such core biopsies. The aim of this study was to evaluate the diagnostic yield of core biopsy specimens obtained using a novel EUS needle specifically designed to obtain core biopsies. Patients and methods: Multicenter retrospective review of all EUS-guided fine-needle biopsies obtained using a novel biopsy needle (SharkCore FNB needle, Medtronic, Dublin, Ireland). Data regarding patient demographics, lesion type/location, technical parameters, and diagnostic yield was obtained. Results: A total of 250 lesions were biopsied in 226 patients (Median age 66 years; 113 (50 %) male). Median size of all lesions (mm): 26 (2 – 150). Overall, a cytologic diagnosis was rendered in 81 % specimens with a median number of 3 passes. When rapid onsite cytologic evaluation (ROSE) was used, cytologic diagnostic yield was 126/149 (85 %) with a median number of 3 passes; without ROSE, cytologic diagnostic yield was 31/45 (69 %, P = 0.03) with a median number of 3 passes. Overall, a pathologic diagnosis was rendered in 130/147 (88 %) specimens with a median number of 2 passes. Pathologic diagnostic yield for specific lesion types: pancreas 70/81 (86 %), subepithelial lesion 13/15 (87 %), lymph node 26/28 (93 %). Ten patients (10/226, 4 %) experienced adverse events: 4 acute pancreatitis, 5 pain, 1 fever/cholangitis. Conclusions: Initial experience with a novel EUS core biopsy needle demonstrates excellent pathologic diagnostic yield with a minimum number of passes. PMID:27652304

  11. ACT-CCREC Core Research Program: Study Questions and Design. ACT Working Paper Series. WP-2015-01

    ERIC Educational Resources Information Center

    Cruce, Ty M.

    2015-01-01

    This report provides a non-technical overview of the guiding research questions and research design for the ACT-led core research program conducted on behalf of the GEAR UP College and Career Readiness Evaluation Consortium (CCREC). The core research program is a longitudinal study of the effectiveness of 14 GEAR UP state grants on the academic…

  12. Optical properties of Au-core Pt-shell nanorods studied using FDTD simulations

    NASA Astrophysics Data System (ADS)

    Liu, Jian-Bo; Long, Lin; Zhang, Yu-Shi; Wang, Yue-Ping; Liu, Feng-Shou; Xu, Wei-Yao; Zong, Ming-Ji; Ma, Lei; Liu, Wen-Qi; Zhang, Hui; Yan, Jiao; Chen, Jia-Qi; Ji, Ying-Lu; Wu, Xiao-Chun

    2016-06-01

    Au-core/Pt-shell nanorods (Au@Pt NRs) have been prepared by a Au nanorod-mediated growth method, and they exhibit high electromagnetic field enhancements under coupling conditions. Boosted by a long-range effect of the high electromagnetic field generated by the Au core, the electromagnetic field enhancement can be controlled by changing the morphology of the nanostructures. In this study, we report the results on the simulations of the electromagnetic field enhancement using a finite difference time domain (FDTD) method, taking the real shapes of the Au@Pt NRs into account. Due to the "hot spot" effect, the electromagnetic field can be localized between the Pt nanodots. The electromagnetic field enhancement is found to be rather independent of the Pt content, whereas the local roughness and small sharp features might significantly modify the near-field. As the electromagnetic field enhancement can be tuned by the distribution of Pt nanodots over the Au-core, Au@Pt NRs can find potential applications in related areas.

  13. A study of the fracture resistance of nyyar cores of three restorative materials.

    PubMed

    Ferrier, Stephen; Sekhon, Balraj S; Brunton, Paul A

    2008-01-01

    Despite the successful use of dental amalgam for coronal-radicular dowel and core build-up in endodontically-treated posterior teeth, newer materials offer many potential advantages over amalgam and have better patient acceptance. This study compared the fracture resistance of coronal-radicular restorations made from three different direct restorative materials. Sixty human premolars were selected, 45 of which were root treated and decoronated. Fifteen of these premolars were restored using amalgam, 15 with composite and 15 using resin-modified glass ionomer. The 15 unrestored teeth were used as a control group. All the teeth were mounted in acrylic within steel containers and subjected to compressive loading to failure on a universal testing machine. The force required to fracture each core specimen was recorded as well as the proportion of core lost due to failure. The results showed dental amalgam as having the highest fracture resistance (mean 1.93kN, sd 0.22) followed by resin-modified glass ionomer (mean 1.05kN, sd 0.20), sound tooth (mean 0.79kN, sd 0.20) and composite (mean 0.75kN, sd 0.11). The differences among all groups were significant. These results demonstrate that, although resin-modified glass ionomer is significantly weaker than amalgam, these restorations were stronger than unrestored teeth and failed at forces in excess of those encountered in normal mastication. Amalgam cores, along with resin-modified glass ionomer, tended to fail less catastrophically than the other materials and, given their strength, would remain the material of choice in situations where abnormally high forces are expected.

  14. Non-invasive methods to study flow and transport at the soil core and lysimeter scale

    NASA Astrophysics Data System (ADS)

    Vereecken, H.

    2004-12-01

    Non-invasive methods offer a great potential to study flow and transport processes at the core to the field and regional scale. In this contribution we will focus on the application of selected techniques such as MRI (Magnetic Resonance Imaging), X-Ray-Tomography (X-RT), MERIT (Magnetic Electrical Resistivity Imaging Technique), GPR (Ground Penetrating Radar) and Spectral Induced Polarisation (SIP) at the core to lysimeter scale. MRI is a powerful tool to derive local scale transport parameters. Based on the imaging of the 3-D temporal evolution of the spatial moments of a solute transport in a soil core, the local scale dispersivity of the soil can be derived. We also use MRI to image the root distribution inside a packed soil column. We employ the effect that the transverse relaxation time of water in the porous medium is considerably smaller than in the root tissue of rizinus communis. Different MRI pulse sequences were tested showing that the best contrast is obtainable by the strongly T2* weighted method CISS. X-RT provides information on the structure of the porous media. By parametrizing this structural information we may obtain an improved description of solute transport in undisturbed soil cores. GPR allows to map the spatial and temporal distribution of soil moisture in large undisturbed lysimeters. Combined with outflow data, this provides unique information to evaluate and improve mathematical models. New developments like MERIT are on their way which additionally exploits the magnetic information inherent in Electrical Resistivity Tomography-experiments to improve the spatial distribution of solute concentrations at lysimeter scale. SIP methods may be used to derive local scale pore size distribution and hydraulic conductivity. The single relaxation times, deduced from a measured phase spectrum either via multi-Cole-Cole-fits or as a whole relaxation time distribution, are a function of the relaxation length, which is connected to pore space

  15. Numerical study on double-diffusive convection in the Earth's core

    NASA Astrophysics Data System (ADS)

    Trümper, T.; Breuer, M.; Hansen, U.

    2012-03-01

    Our numerical study focuses on convection in a rotating spherical shell with the objective to model combined thermal and compositional convection as proposed for the Earth's core. Since the core is cooling, a thermal gradient is established, which can drive thermal convection. Simultaneously, due to the solidification of the inner core latent heat is released at the freezing front and the concentration of the light constituents of the liquid phase increases thus providing a source for compositional buoyancy. Typically, the molecular diffusivities of both driving components differ by some orders of magnitude. To account for this difference it is indicated to adopt a double-diffusive convection model in treating Earth's core dynamics. As opposed to purely thermal or purely compositional convection the double-diffusive system is controlled by two Rayleigh numbers associated with the respective buoyancy sources. Using the Rayleigh numbers as control parameters neutral curves of the linear onset of convection in the rotating shell are determined for different Ekman numbers and diffusivity ratios. It is found that the neutral curves depend significantly on the system parameters. By comparison with the analytical solutions of the rotating cylindrical annulus it is shown that the neutral curves represent a superposition of curves associated with solutions for different azimuthal wave numbers. Furthermore, fully non-linear simulations are presented in order to elucidate the effect of isochemical and fixed chemical flux boundary conditions on the convection. We consider three driving scenarios with varying thermo-chemical forcing ratios. Both the forcing ratio and the chemical boundary condition have distinct effects on the system that are discussed separately.

  16. Bacterial study of Vostok drilling fluid: the tool to make ice core finding confident

    NASA Astrophysics Data System (ADS)

    Alekhina, I. A.; Petit, J. R.; Lukin, V. V.; Bulat, S. A.

    2003-04-01

    Decontamination of Vostok ice core is a critical issue in molecular biology studies. Core surface contains a film of hardly removable 'dirty' drilling fluid representing a mixture of polyhydrocarbons (PHC) including polyaromatic hydrocarbons (PAH) and freon. To make ice microbial finding more confident the original Vostok drilling fluid sampled from different depths (110m - 3600m) was analyzed for bacterial content by ribosomal DNA sequencing. Total, 33 clones of 16S ribosomal DNA were recovered from four samples of drilling fluid at 110, 2750, 3400, and 3600m leading to identification of 8 bacterial species. No overlapping was observed even for neighboring samples (3400m and 3600m). At present four major bacteria with the titer more than 103-104 cells per ml (as estimated from PCR results) are identified. Among them we found: unknown representative of Desulfobacteraceae which are able to oxidize sulphates and degrade benzenes (110m); PAH-degrading alpha-proteobacterium Sphingomonas natatoria (3400m); alpha-proteobacterium representing closely-related group of Sphingomonas sp. (e.g., S. aurantiaca) which are able to degrade PAH as well, and human pathogen closely related to Haloanella gallinarum of CFB group (3600m). Four additional species were revealed as single clones and showed relatedness to human pathogens and saprophytes as well as soil bacteria. These bacteria may represent drilling fluid contaminants introduced during its sampling or DNA extraction procedure. Of four major bacteria revealed, one species, Sphingomonas natatoria, has been met by us in the Vostok core from 3607 m depth (AF532054) whereas another Sphingomonas sp. which we refer to as S. aurantiaca was found in Antarctic microbial endolithic community (AF548567), hydrocarbon-containing soil near Scott Base in Antarctica (AF184221) and even isolated from 3593m Vostok accretion ice (AF324199) and Taylor Dome core (AF395031). The source for major human pathogen-related bacteria is rather uncertain

  17. Pathologic evaluation of a new endoscopic ultrasound needle designed to obtain core tissue samples: A pilot study

    PubMed Central

    Adler, Douglas G.; Witt, Benjamin; Chadwick, Barbara; Wells, Jason; Taylor, Linda Jo; Dimaio, Christopher; Schmidt, Robert

    2016-01-01

    Background and Objectives: Standard endoscopic ultrasound-fine-needle aspiration (EUS-FNA) needles are in widespread use. Meaningful differences between the available needles have been difficult to identify. Recently, a new EUS needle (Shark Core®, Covidien, Dublin, Leinster, Ireland), has been introduced in an attempt to improve diagnostic accuracy, tissue yield, and to potentially obtain a core tissue sample. We performed a pilot study prospectively to evaluate this new needle when compared to a standard EUS-FNA needle. Materials and Methods: Analysis of the first 15 patients undergoing EUS-FNA with the Shark Core needle was performed and it was compared to EUS-FNA in 15 patients who underwent EUS-FNA with a standard needle. Results: The Shark Core needle required fewer needle passes to obtain diagnostic adequacy than the standard needle [(χ2(1) = 11.3, P < 0.001]. The Shark Core needle required 1.5 passes to reach adequacy, whereas the standard needle required three passes. For cases with cell blocks, the Shark Core needle produced diagnostic material in 85% of cases [95% confidence interval (CI): 54–98], whereas the standard needle produced diagnostic material in 38% of the cases (95% CI: 9-76). The Shark Core needle produced actual tissue cores 82% of the time (95% CI: 48–98) and the standard needle produced no tissue cores (95% CI: 0-71) (P = 0.03). Conclusion: This pilot study found that the Shark Core needle had a high rate of producing adequate cytologic material for the diagnosis of pancreatic and peri-pancreatic lesions sampled by EUS with fewer passes required to obtain a definitive diagnosis and with a high rate of tissue cores being obtained when compared to a standard FNA needle. PMID:27386475

  18. The contribution of ice core studies to the understanding of environmental processes

    NASA Astrophysics Data System (ADS)

    Oeschger, H.

    Data obtained from the studies of polar ice cores supplement the records available from tree rings, peat bogs, lake and ocean sediments, and provide a relatively new data source to understand processes of the complex climatic and global cycles. The main sources of ice core data are stable and radioactive isotopes, soluble and particulate matter, and the composition of the gases occluded in the ice. Such information can be used to investigate the history and the variability of carbon dioxide and the climate system. Temperature and other climatic data obtained from δ18O measurements of polar ice cores can be correlated with similar information obtained from carbonate lake sediments. Comparison of the δ18O profiles of the Dye 3 ice core and central European lake sediments show distinct similarities such as the identification of the Older Dryas-Bolling/Allerød-Younger Dryas-Preboreal sequence. Measurements of the cosmic ray produced isotope 10Be on only 1 kg polar ice samples are possible by accelerator mass spectrometry. The resulting data reveals the 11-year solar modulation cycle and the Maunder Minimum of solar activity from 1645 to 1745 AD. The 10Be concentration values for the Maunder Minimum are a factor 1.6 higher than the average for the past 800 years. Using a carbon cycle model these 10Be variations can be compared to the 14C variations found in tree rings. The relatively good correlation suggests a common origin of the 10Be and 14C fluctuations and serves as a check of carbon cycle models. During the Wisconsin stage all of the Dye 3 ice core parameters measured to date (δ18O, CO2/air, SO4-, NO3-, Cl-, dust) show values fluctuating between two different boundary conditions. This suggests that the climate system existing at that time oscillated between a cold and a warm state, probably strongly influenced by different ocean circulations and ice cover. During the Wisconsin stage a cold system dominated; the transition to the Holocene is considered as the

  19. Influence of polar substituent on central bending unit of bent core mesogens: Synthesis, photophysical, mesomorphism and DFT studies

    NASA Astrophysics Data System (ADS)

    Paul, Manoj Kumar; Kalita, Gayatri; Bhattacharya, Barnali; Sarkar, Utpal

    2016-09-01

    New five ring bent core mesogens derived from substituted 1,3-phenylenediamine (4-nitro-1,3-phenylenediamine, 4-chloro-1,3-phenylenediamine) were synthesized. Their molecular structures, photophysical properties and mesogenic behaviors were investigated. The molecular structures and the purity of the bent core molecule have been characterized by spectroscopic studies and elemental analysis respectively. Photophysical properties of bent core compounds were investigated in chloroform by using UV-visible and fluorescence spectroscopic studies. The phase transition temperatures were detected by differential scanning calorimetry analysis and the phases are confirmed by polarizing optical microscopy. The polar substituents on bent core unit of bent shaped molecule influence the mesomorphic behaviors of the bent core mesogens. The polar nitro group at 4-position of the bent core unit displays tilted smectic C phase and unknown smectic X phase whereas chloro group at 4-position exhibits orthogonal smectic A phase. The bent core mesogens are fluorescent in nature. The density functional theory calculation was carried out to obtain the stable molecular conformation and chemical reactivity of the bent core molecules. Orbitals involved in the electronic transitions and their corresponding energies together with oscillator strengths have been reported.

  20. Nondestructive X-Ray Computed Tomography Analysis of Sediment Cores: A Case Study from the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Oti, E.; Polyak, L. V.; Cook, A.; Dipre, G.

    2014-12-01

    Investigation of marine sediment records can help elucidate recent changes in the Arctic Ocean circulation and sea ice conditions. We examine sediment cores from the western Arctic Ocean, representing Late to Early Quaternary age (potentially up to 1 Ma). Previous studies of Arctic sediment cores indicate that interglacial/interstadial periods with relatively high sea levels and reduced ice cover are characterized by vigorous bioturbation, while glacial intervals have little to no bioturbation. Traditional methods for studying bioturbation require physical dissection of the cores, effectively destroying them. To treat this limitation, we evaluate archival sections of the cores using an X-ray Computed Tomography (XCT) scanner, which noninvasively images the sediment cores in three dimensions. The scanner produces density sensitive images suitable for quantitative analysis and for identification of bioturbation based on size, shape, and orientation. We use image processing software to isolate burrows from surrounding sediment, reconstruct them three-dimensionally, and then calculate their surface areas, volumes, and densities. Preliminary analysis of a core extending to the early Quaternary shows that bioturbation ranges from 0 to approximately 20% of the core's volume. In future research, we will quantitatively define the relationship between bioturbation activity and glacial regimes. XCT examination of bioturbation and other sedimentary features has the potential to shed light on paleoceanographic conditions such as sedimentation patterns and food flux. XCT is an alternative, underexplored investigation method that bears implications not only for illustrating paleoclimate variations but also for preserving cores for future, more advanced technologies.

  1. Detailed study of macrobending effects in a wide transmission bandwidth hollow-core photonic bandgap fiber

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Sandoghchi, S. R.; Numkam, E.; Bradley, T. D.; Hayes, J. R.; Wheeler, N. V.; Jasion, G.; Gray, D. R.; Poletti, F.; Petrovich, M. N.; Richardson, D. J.

    2016-04-01

    We study in detail the macrobending effects in a wide transmission bandwidth (~200nm) 19 cell hollow-core photonic bandgap fiber operating at 1550nm. Our results indicate low bend sensitivity over a ~130nm wide interval within the transmission window, with negligible loss (<0.1dB) for bending radii down to 5mm. The "red shift" and "blue shift" of the bandgap edge have been observed at the short and long wavelength edges, respectively. The cutoff wavelengths where air-guiding modes stop guiding can be extracted from the bending loss spectra, which matches well with the simulated effective refractive index map of such fiber.

  2. Structure of Smectic Defect Cores: X-Ray Study of 8CB Liquid Crystal Ultrathin Films

    SciTech Connect

    Michel, Jean-Philippe; Lacaze, Emmanuelle; Goldmann, Michel; Gailhanou, Marc; Boissieu, Marc de; Alba, Michel

    2006-01-20

    We study the structure of very thin liquid crystal films frustrated by antagonistic anchorings in the smectic phase. In a cylindrical geometry, the structure is dominated by the defects for film thicknesses smaller than 150 nm and the detailed topology of the defects' cores can be revealed by x-ray diffraction. They appear to be split in half tube-shaped rotating grain boundaries (RGB). We determine the RGB spatial extension and evaluate its energy per unit length. Both are significantly larger than the ones usually proposed in the literature.

  3. Core compressor exit stage study. Volume 4: Data and performance report for the best stage configuration

    NASA Technical Reports Server (NTRS)

    Wisler, D. C.

    1981-01-01

    The core compressor exit stage study program develops rear stage blading designs that have lower losses in their endwall boundary layer regions. The test data and performance results for the best stage configuration consisting of Rotor-B running with Stator-B are described. The technical approach in this efficiency improvement program utilizes a low speed research compressor. Tests were conducted in two ways: (1) to use four identical stages of blading to obtain test data in a true multistage environment and (2) to use a single stage of blading to compare with the multistage test results. The effects of increased rotor tip clearances and circumferential groove casing treatment are evaluated.

  4. Influence of Full Veneer Restoration on Fracture Resistance of Three Different Core Materials: An Invitro Study

    PubMed Central

    Manoharan, P.S; Shekhawat, Kuldeep Singh; Deb, Saikat; Chidambaram, S.; Konchada, Jagadish; Venugopal, Nirupa; Vadivel, Harish

    2015-01-01

    Aims and Objectives One of the factor which affects the strength of the tooth restored with core material is the property of the material. In clinical situation all such restored teeth are protected by crowns. This study evaluated the strength of different core materials on a compromised tooth structure after restoration with a crown. Materials and Methods Seventy extracted intact human premolars were collected and mounted within a mould using auto-polymerizing resin. The teeth were divided in-to four groups - A, B, C and D. Each group contained 20 teeth except group A with 10 teeth. All the teeth were prepared for full veneer cast crown. Except for the teeth in group: A) extensive class-I cavities were prepared in the teeth of all the groups and restored with; B) composite resin, 3M EPSE Filtek P60; C) Silver reinforced glass ionomer, SHOFU Hi Dense XP and; (D) Resin reinforced glass ionomer, GC Gold Label light cure GIC. All the teeth were restored with cast-metal alloy and exposed to 1.2 million cycles of cyclic loading in a chewing simulator. Subsequently, the teeth that survived were loaded till fracture in the universal testing machine. Fracture loads and type of fractures were recorded. Results All the specimens survived cyclic loading. The mean fracture strength of the silver reinforced glass ionomer was greater with and without crown (p<0.001). Statistical analysis for the mean fracture load of each specimen showed significant difference between the groups. Conclusion Under the condition of this study, core materials when restored with artificial crown had a significant increase in fracture resistance. PMID:26501004

  5. Multidisciplinary Study of the Precambrian Biosphere and Surficial Oxygenation, Kaapvaal Craton, South Africa: The Agouron Cores

    NASA Astrophysics Data System (ADS)

    Kirschvink, J. L.; Beukes, N. J.; Evans, D. A.; Grotzinger, J. P.; Knoll, A. H.; Sumner, D. Y.

    2004-12-01

    The Campbellrand-Kuruman carbonate-iron formation stratigraphic succession, which drapes the Kaapvaal craton of South Africa, provides a unique opportunity to study the latest Archean/Earliest Proterozoic time interval in a multidisciplinary fashion, for four principal reasons: 1) The >1 km-thick succession of carbonates, cherts, shales, and associated iron formations is a storehouse of various geochemical and paleoclimatic proxy records, 2) the carbonate platform has never been significantly buried and contains abundant limestone, thus offering strong potential for preservation of organic biomarkers, 3) the occurrence of early chert and abundant early sea-floor carbonate crusts provide good potential for the preservation of microfossils and magnetofossils, and 4) much of the stratigraphic succession has not been significantly deformed and we have estabilshed a chronostratigraphic framework in which shallow water facies can be traced down the ancient paleoslope into facies deposited at water depths > 250 meters within a sequence stratigraphic context, supplemented with correlation of three impact spherule layers. The geologic framework provided by this sequence of rock offers an unparalleled opportunity to study the structure and composition of the Archean ocean and to merge this information with co-existing paleontological and geochemical records. With support from the Agouron Institute, two separate cores, each ~ 1.5 km in length, were drilled through the margin of the carbonate platform, spaced so as to intercept the transitional facies at two paleodepths. The holes were deviated slightly from vertical so that a ball-mark system could be used to obtain absolute orientation. To enhance the utility for paleomagnetic investigations, core barrels and bits were demagnetized routinely with a portable mu-metal shielded coil assembly to reduce remagnetization problems, and all core slicing was done with non-magnetic blades. To minimize contamination problems for

  6. Petrologic studies of drill cores USW-G2 and UE25b-1H, Yucca Mountain, Nevada

    SciTech Connect

    Caporuscio, F.; Vaniman, D.; Bish, D.; Broxton, D.; Arney, B.; Heiken, G.; Byers, F.; Gooley, R.; Semarge, E.

    1982-07-01

    The tuffs of the Nevada Test Site are currently under investigation as a possible deep geologic site for high-level radioactive waste disposal. This report characterizes tuff retrieved in core from two drill holes, USW-G2 and UE25b-1H, at the Yucca Mountain block. The USW-G2 drill core is from the northernmost extent of the block, whereas UE25b-1H is adjacent to an earlier drill hole, UE25a-1. The drill cores USW-G2 and UE25b-1H bottomed at 6000 and 4200 ft, respectively. Petrographic and x-ray diffraction studies of the two drill cores are presented in this report and indicate that tuffs (composed primarily of variably welded ash flows) are partially recrystallized to secondary minerals. Correlations of stratigraphy are also made with previous drill cores from Yucca Mountain.

  7. Core Competencies: The Challenge For Graduate Peace and Conflict Studies Education

    NASA Astrophysics Data System (ADS)

    Windmueller, John; Wayne, Ellen Kabcenell; Botes, Johannes (Jannie)

    2009-05-01

    This article uses a case study of the assessment of a graduate program in negotiations and conflict management as a springboard for discussing several critical, but unanswered questions in our field. It raises questions regarding the lack of clear core competencies and expectations regarding curricula at the graduate-level of peace and conflict studies programs, as well as concerns over how educators in this field can or should assess their own work and train students for practice. It also addresses, via a comparative case analysis in Tajikistan, the degree to which the competencies and pedagogical approaches in this field are culturally bound. The picture that emerges from these case studies suggests that there have been important omissions in the way that the varied educational programs and the larger peace and conflict studies field itself have developed thus far.

  8. Developing a common bean core collection suitable for association mapping studies

    PubMed Central

    Perseguini, Juliana Morini Küpper Cardoso; Silva, Gliciane Micaele Borges; Rosa, João Ricardo Bachega Feijó; Gazaffi, Rodrigo; Marçal, Jéssica Fernanda; Carbonell, Sérgio Augusto Morais; Chiorato, Alisson Fernando; Zucchi, Maria Imaculada; Garcia, Antonio Augusto Franco; Benchimol-Reis, Luciana Lasry

    2015-01-01

    Because of the continuous introduction of germplasm from abroad, some collections have a high number of accessions, making it difficult to explore the genetic variability present in a germplasm bank for conservation and breeding purposes. Therefore, the aim of this study was to quantify and analyze the structure of genetic variability among 500 common bean accessions to construct a core collection. A total of 58 SSRs were used for this purpose. The polymorphism information content (PIC) in the 180 common bean accessions selected to compose the core collection ranged from 0.17 to 0.86, and the discriminatory power (DP) ranged from 0.21 to 0.90. The 500 accessions were clustered into 15 distinct groups and the 180 accessions into four distinct groups in the Structure analysis. According to analysis of molecular variance, the most divergent accessions comprised 97.2% of the observed genetic variability present within the base collection, confirming the efficiency of the selection criterion. The 180 selected accessions will be used for association mapping in future studies and could be potentially used by breeders to direct new crosses and generate elite cultivars that meet current and future global market needs. PMID:25983627

  9. A study of corrosion-resistant materials for pulsed gaseous core nuclear systems

    SciTech Connect

    Whitney, E.D.; Kim, D.J.; Tucker, D.S.

    1985-05-01

    The containment of an aggressive high-temperature reactive fluoride atmosphere, such as exists in a pulsed gaseous core nuclear system, requires the use of protective materials that will either not react in this environment or will form stable nonvolatile fluorides, thus passivating the surface against further reaction. Candidate protective materials for gaseous core reactors were identified for further investigation on the basis of their thermodynamic and mechanical properties. Materials included aluminum oxide (Al/sub 2/O/sub 3/), yttrium oxide (Y/sub 2/O/sub 3/), mixtures of Al/sub 2/O/sub 3/ and Y/sub 2/O/sub 3/, magnesium oxide (MgO), and pyrophyllite (Al/sub 2/(Si/sub 2/O/sub 5/)/sub 2/(OH)/sub 2/). Pioneering studies at the University of Florida on the use of infrared reflection spectroscopy (IRRS) for nondestructive surface analysis, along with x-ray diffraction pattern (XDP) studies, were applied to the analysis of UF/sub 6/ material/surface interactions. Candidate materials were subjected to a UF/sub 6/ atmosphere (973 K, 87 Torr, with 1- to 5-h exposures). The IRRS and XDP analyses of the materials after exposure showed no surface product formation in the case of the first four protective materials. For pyrophyllite, a mechanically and chemically stable protective surface fluoride film was formed.

  10. Developing a common bean core collection suitable for association mapping studies.

    PubMed

    Perseguini, Juliana Morini Küpper Cardoso; Silva, Gliciane Micaele Borges; Rosa, João Ricardo Bachega Feijó; Gazaffi, Rodrigo; Marçal, Jéssica Fernanda; Carbonell, Sérgio Augusto Morais; Chiorato, Alisson Fernando; Zucchi, Maria Imaculada; Garcia, Antonio Augusto Franco; Benchimol-Reis, Luciana Lasry

    2015-03-01

    Because of the continuous introduction of germplasm from abroad, some collections have a high number of accessions, making it difficult to explore the genetic variability present in a germplasm bank for conservation and breeding purposes. Therefore, the aim of this study was to quantify and analyze the structure of genetic variability among 500 common bean accessions to construct a core collection. A total of 58 SSRs were used for this purpose. The polymorphism information content (PIC) in the 180 common bean accessions selected to compose the core collection ranged from 0.17 to 0.86, and the discriminatory power (DP) ranged from 0.21 to 0.90. The 500 accessions were clustered into 15 distinct groups and the 180 accessions into four distinct groups in the Structure analysis. According to analysis of molecular variance, the most divergent accessions comprised 97.2% of the observed genetic variability present within the base collection, confirming the efficiency of the selection criterion. The 180 selected accessions will be used for association mapping in future studies and could be potentially used by breeders to direct new crosses and generate elite cultivars that meet current and future global market needs.

  11. [Study on trace elements of lake sediments by ICP-AES and XRF core scanning].

    PubMed

    Cheng, Ai-Ying; Yu, Jun-Qing; Gao, Chun-Liang; Zhang, Li-Sha; He, Xian-Hu

    2013-07-01

    It is the first time to study sediment of Toson lake in Qaidam Basin. Trace elements including Cd, Cr, Cu, Zn and Pb in lake sediment were measured by ICP-AES method, studied and optimized from different resolution methods respectively, and finally determined a optimum pretreatment system for sediment of Toson lake, namely, HCl-HNO3-HF-HClO4-H2O2 system in the proportions of 5 : 5 : 5 : 1 : 1 was determined. At the same time, the data measured by XRF core scanning were compared, the use of moisture content correction method was analyzed, and the influence of the moisture content on the scanning method was discussed. The results showed that, compared to the background value, the contents of Cd and Zn were a little higher, the content of Cr, Cu and Pb was within the background value limits. XRF core scanning was controlled by sediment elements as well as water content in sediment to some extent. The results by the two methods showed a significant positive correlation, with the correlation coefficient up to 0.673-0.925, and they have a great comparability.

  12. A STUDY OF A FAILED CORONAL MASS EJECTION CORE ASSOCIATED WITH AN ASYMMETRIC FILAMENT ERUPTION

    SciTech Connect

    Joshi, Navin Chandra; Srivastava, Abhishek K.; Uddin, Wahab; Kayshap, Pradeep; Filippov, Boris; Chandra, Ramesh E-mail: njoshi98@gmail.com

    2013-07-01

    We present multi-wavelength observations of an asymmetric filament eruption and associated coronal mass ejection (CME) and coronal downflows on 2012 June 17 and 18 from 20:00-05:00 UT. We use SDO/AIA and STEREO-B/SECCHI observations to understand the filament eruption scenario and its kinematics, while LASCO C2 observations are analyzed to study the kinematics of the CME and associated downflows. SDO/AIA limb observations show that the filament exhibits a whipping-like asymmetric eruption. STEREO/EUVI disk observations reveal a two-ribbon flare underneath the southeastern part of the filament that most probably occurred due to reconnection processes in the coronal magnetic field in the wake of the filament eruption. The whipping-like filament eruption later produces a slow CME in which the leading edge and the core propagate, with an average speed of Almost-Equal-To 540 km s{sup -1} and Almost-Equal-To 126 km s{sup -1}, respectively, as observed by the LASCO C2 coronagraph. The CME core formed by the eruptive flux rope shows outer coronal downflows with an average speed of Almost-Equal-To 56 km s{sup -1} after reaching Almost-Equal-To 4.33 R{sub Sun }. Initially, the core decelerates at Almost-Equal-To 48 m s{sup -2}. The plasma first decelerates gradually up to a height of Almost-Equal-To 4.33 R{sub Sun} and then starts accelerating downward. We suggest a self-consistent model of a magnetic flux rope representing the magnetic structure of the CME core formed by an eruptive filament. This rope loses its previous stable equilibrium when it reaches a critical height. With some reasonable parameters, and inherent physical conditions, the model describes the non-radial ascending motion of the flux rope in the corona, its stopping at some height, and thereafter its downward motion. These results are in good agreement with observations.

  13. A Combined He and Os Isotopic Study of the HSDP-2 Core from Mauna Kea, Hawaii

    NASA Astrophysics Data System (ADS)

    Ireland, T. J.; Walker, R. J.; Depaolo, D. J.; Kurz, M. D.

    2004-12-01

    Combined osmium and helium isotope systematics of hotspot lavas have the potential to reveal information about the deep Earth. A high 3He/4He ratio may represent an undegassed reservoir, generally associated with the lower mantle. There are two Os isotopes that can be studied to help to further elucidate the problem. The decay of 187Re to 187Os is the more frequently cited system; however, in terms of lower mantle processes, the decay of 190Pt to 186Os may be extremely useful. Both of these Os isotopes are enriched in the core relative to chondritic values. In a previous study, Brandon et al. (1999) examined several Hawaiian volcanoes for both He and Os isotopes. A correlation was noted between the 3He/4He, 187Os/188Os and 186Os/188Os ratios. In terms of 3He/4He and 187Os/188Os space, the three commonly cited Hawaiian end-members (Kea, Koolau and Loihi members) were clearly defined. A strong positive correlation was also observed for 186Os/188Os versus 3He/4He. These correlations were interpreted as a possible signature of core-mantle interaction. There were some limitations to previous studies. Only 2-3 samples from each volcano were studied, with these samples generally being subaerially erupted. The He data utilized were often not for the same samples for which the Os data were collected (volcano averages for He were used on some samples). With the introduction of data from the Hawaiian Scientific Drilling Project (HSDP-2), which drilled 2.84 km into the Mauna Kea volcanics (DePaolo et al., 2000), an extensive history of a single volcano can be observed (from the early submarine stages to the later subaerial rocks). In the current study a detailed Os isotopic analysis of several samples that span a large depth range of the HSDP-2 core, in conjunction with previously collected He isotopic data (Kurz et al., 2004), was conducted. The samples define a relatively narrow range of slightly suprachondritic 187Os/188Os ratios (0.12865-0.13056), despite having a large

  14. Optical and electrical study of core-shell silicon nanowires for solar applications.

    PubMed

    Li, Zhenhua; Wang, Jian; Singh, Navab; Lee, Sungjoo

    2011-09-12

    In this work, we report a CMOS comparable fabrication process of core-shell SiNW solar cell from single-crystalline p-type Si(100) test wafers. Optical lithography defined plasma etching was used to form highly ordered vertical SiNW arrays, which display a drastic reduction in optical reflectance over a wide range of wavelengths. BF(2) and P ion implantations were employed for producing a sharp and shallow radial p-n junction. Under AM 1.5G illumination, the device demonstrates a short circuit current density (Jsc) of 14.2 mA/cm(2), an open circuit voltage (Voc) of 0.485 V and a fill factor (FF) of 42.9%, giving a power conversion efficiency (PCE) of 2.95%. The Jsc observed is 52% higher than that in the control device with planar Si p-n junction, indicating significant enhancement in carrier generation and collection efficiency from the core-shell structure. Impact of series resistance (Rs) is also studied, highlighting potential improvement of PCE to 4.40% in the absence of Rs. With top contact optimized, PCE could further increase to 6.29%.

  15. Bent-core fiber structure: Experimental and theoretical studies of fiber stability

    NASA Astrophysics Data System (ADS)

    Bailey, C.; Gartland, E.; Jakli, A.

    2007-03-01

    Recent studies have shown that bent core liquid crystals in the B7 and B2 phases can form stable freestanding fibers with a so called ``jelly-roll'' layer configuration, which means that the smectic layers would be arranged in concentric cylindrical shells. This configuration shows layer curvature is necessary for fiber stability. Classically this effect would destabilize the fiber configuration because of the energy cost of layer distortions and surface tension. We propose a model that can predict fiber stability in the experimentally observed range of a few micrometers, by assuming that layer curvature can be stabilized by including a term dealing with the linear divergence of the polarization direction if the polarization is allowed to have a component normal to the smectic layers. We show that this term can stabilize the fiber configuration if its strength is larger than the surface tension. We also propose an entropic model to explain the strength of this term by considering steric effects. Finally we will take results from this model and apply them to better understand experimental findings of bent-core fibers. Financial support by NSF FRG under contract DMS-0456221. Prof. Daniel Phillips, Particia Bauman and Jie Shen at Purdue Univ., Prof. Maria Carme Calderer at Univ. of Minnesota, and Prof. Jonathan Selinger at Kent State Univ. Liou Qiu and Dr. O.D. Lavrentovich, Characterization Facilities, Liquid Crystal Institute, Kent State Univ. Julie Kim and Dr. Quan Li, Chemical Synthesis Facilities, Liquid Crystal Institute, Kent State Univ.

  16. Developing core interprofessional competencies for community rehabilitation practitioners: findings from an Australian study.

    PubMed

    Kendall, E; Muenchberger, H; Catalano, T; Amsters, D; Dorsett, P; Cox, R

    2011-03-01

    This study aimed to determine the core competencies that underpin the practice of community rehabilitation (CR) practitioners working in a single state in Australia. Using a recursive and consultative methodology designed to build consensus, CR professionals, trainers, educators, and researchers developed a preliminary set of core interprofessional competencies that were considered essential to their practice. Data were collected in four main stages that engaged practitioners and experts in the CR field in the process of identifying, defining, validating, and endorsing a set of competencies. The first stage involved focus groups with 50 senior practitioners in metropolitan, rural/remote, regional, and indigenous communities. The second and third stages involved expert panels consisting of 20 trainers/educators, senior leaders, and scholars who refined, defined and validated the competency areas and developed statements that reflected the data.These statements formed the basis of a survey that was distributed to all current CR practitioners based in this state for endorsement, 40 of whom responded. Ten competencies emerged from this process. Although there are limitations to the application of competencies, they will have significant implications for the future training of CR practitioners who can transcend professional boundaries.

  17. Natrelle Round Silicone Breast Implants: Core Study Results at 10 Years

    PubMed Central

    Murphy, Diane K.

    2014-01-01

    Background: Allergan’s Natrelle round silicone-filled breast implants were approved by the U.S. Food and Drug Administration in 2006 based on interim results from the Core Study; final 10-year study results are now available. Methods: Seven hundred fifteen subjects were implanted with smooth and Biocell textured Natrelle round silicone implants and attended clinic visits at 0 to 4 weeks, 6 months, 1 year, and annually through 10 years. Approximately one-third of subjects underwent magnetic resonance imaging at years 1, 3, 5, 7, and 9 to assess rupture. Results: Complication rates showed modest increases over the previously published 6-year rates. The Kaplan-Meier capsular contracture rate was 18.9 percent for augmentation, 28.7 percent for revision-augmentation, and 24.6 percent for reconstruction. Among augmentation subjects, capsular contracture was significantly lower (p = 0.023) for submuscular (15.7 percent) versus subglandular (26.3 percent) placement. The overall rupture rate in the magnetic resonance imaging cohort was 13.0 percent for subjects and 7.7 percent for implants. By the end of the study, 81.8 percent of augmentation subjects still had an original implant in place. Using a five-point scale, 94.2 percent of augmentation, 83.8 percent of revision-augmentation, and 90.7 percent of reconstruction subjects reported being satisfied or definitely satisfied with their implants. Significant improvement over baseline was also seen in overall breast satisfaction and satisfaction with breast size, shape, feel, and how well they matched. Conclusion: The 10-year data from the Natrelle Core Study, which can guide surgeons and patients in decision-making, demonstrate safety and high levels of patient satisfaction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III. PMID:24867717

  18. Tracer and hydrometric study of preferential flow in large undisturbed soil cores from the Georgia Piedmont, USA

    USGS Publications Warehouse

    McIntosh, Janice; McDonnell, Jeffrey J.; Peters, Norman E.

    1999-01-01

    We studied the temporal patterns of tracer throughput in the outflow of large (30 cm diameter by 38 cm long) undisturbed cores from the Panola Mountain Research Watershed, Georgia. Tracer breakthrough was affected by soil structure and rainfall intensity. Two rainfall intensities (20 and 40 mm hr-1) for separate Cl- and Br- amended solutions were applied to two cores (one extracted from a hillslope soil and one extracted from a residual clay soil on the ridge). For both low and high rainfall intensity experiments, preferential flow occurred in the clay core, but not in the hillslope core. The preferential flow is attributed to well-developed interpedal macrochannels that are commonly found in structured clay soils, characteristic of the ridge site. However, each rainfall intensity exceeded the matrix infiltration capacity at the top of the hillslope core, but did not exceed the matrix infiltration capacity at the middle and bottom of the hillslope core and at all levels in the clay core. Localized zones of saturation created when rainfall intensity exceeds the matrix infiltration capacity may cause water and tracer to overflow from the matrix into macrochannels, where preferential flow occurs to depth in otherwise unsaturated soil. Copyright © 1999 John Wiley & Sons, Ltd.

  19. Tracer and hydrometric study of preferential flow in large undisturbed soil cores from the Georgia Piedmont, USA

    NASA Astrophysics Data System (ADS)

    McIntosh, Janice; McDonnell, Jeffrey J.; Peters, Norman E.

    1999-02-01

    We studied the temporal patterns of tracer throughput in the outflow of large (30 cm diameter by 38 cm long) undisturbed cores from the Panola Mountain Research Watershed, Georgia. Tracer breakthrough was affected by soil structure and rainfall intensity. Two rainfall intensities (20 and 40 mm hr-1) for separate Cl- and Br- amended solutions were applied to two cores (one extracted from a hillslope soil and one extracted from a residual clay soil on the ridge). For both low and high rainfall intensity experiments, preferential flow occurred in the clay core, but not in the hillslope core. The preferential flow is attributed to well-developed interpedal macrochannels that are commonly found in structured clay soils, characteristic of the ridge site. However, each rainfall intensity exceeded the matrix infiltration capacity at the top of the hillslope core, but did not exceed the matrix infiltration capacity at the middle and bottom of the hillslope core and at all levels in the clay core. Localized zones of saturation created when rainfall intensity exceeds the matrix infiltration capacity may cause water and tracer to overflow from the matrix into macrochannels, where preferential flow occurs to depth in otherwise unsaturated soil.

  20. International perspective on common core competencies for occupational physicians: a modified Delphi study

    PubMed Central

    Lalloo, Drushca; Demou, Evangelia; Kiran, Sibel; Cloeren, Marianne; Mendes, René; Macdonald, Ewan B

    2016-01-01

    Objectives The competencies required of occupational physicians (OPs) have been the subject of peer-reviewed research in Europe and individual countries around the world. In the European Union (EU), there has been development of guidance on training and common competencies, but little research has extended beyond this. The aim of this study was to obtain consensus on and identify the common core competencies required of OPs around the world. Methods A modified Delphi study was carried out among representative organisations and networks of OPs in a range of countries around the world. It was conducted in 2 rounds using a questionnaire based on the specialist training syllabus of a number of countries, expert panel reviews and conference discussions. Results Responses were received from 51 countries around the world, with the majority from Europe (60%; 59%) and North and South America (24%; 32%) in rounds 1 and 2, respectively. General principles of assessment and management of occupational hazards to health and good clinical care were jointly considered most important in ranking when compared with the other topic areas. Assessment of disability and fitness for work, communication skills and legal and ethical issues completed the top five. In both rounds, research methods and teaching and educational supervision were considered least important. Conclusions This study has established the current priorities among OPs across 51 countries of the common competencies required for occupational health (OH) practice. These findings can serve as a platform for the development of common core competencies/qualifications within specific geographical regions or internationally. This is particularly pertinent with globalisation of commerce and free movement within the EU. PMID:27076063

  1. A comparative study on liquid core formulation on the diameter on the alginate capsules

    NASA Astrophysics Data System (ADS)

    Ong, Hui-Yen; Lee, Boon-Beng; Radzi, AkmalHadi Ma'; Zakaria, Zarina; Chan, Eng-Seng

    2015-08-01

    Liquid core capsule has vast application in biotechnology related industries such as pharmaceutical, medical, agriculture and food. Formulation of different types of capsule was important to determine the performance of the capsule. Generally, the liquid core capsule with different formulations generated different size of capsule.Therefore, the aim of this project is to investigate the effect of different liquid core solution formulations on the diameter of capsule. The capsule produced by extruding liquid core solutions into sodium alginate solution. Three types of liquid core solutions (chitosan, xanthan gum, polyethylene glycol (PEG)) were investigated. The results showed that there is significant change in capsule diameter despite in different types of liquid core solution were used and a series of capsule range in diameter of 3.1 mm to 4.5 mm were produced. Alginate capsule with chitosan formulation appeared to be the largest capsule among all.

  2. Synthesis and cytotoxicity study of magnesium ferrite-gold core-shell nanoparticles.

    PubMed

    Nonkumwong, Jeeranan; Pakawanit, Phakkhananan; Wipatanawin, Angkana; Jantaratana, Pongsakorn; Ananta, Supon; Srisombat, Laongnuan

    2016-04-01

    In this work, the core-magnesium ferrite (MgFe2O4) nanoparticles were prepared by hydrothermal technique. Completed gold (Au) shell coating on the surfaces of MgFe2O4 nanoparticles was obtained by varying core/shell ratios via a reduction method. Phase identification, morphological evolution, optical properties, magnetic properties and cytotoxicity to mammalian cells of these MgFe2O4 core coated with Au nanoparticles were examined by using a combination of X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy, UV-visible spectroscopy (UV-vis), vibrating sample magnetometry and resazurin microplate assay techniques. In general, TEM images revealed different sizes of the core-shell nanoparticles generated from various core/shell ratios and confirmed the completed Au shell coating on MgFe2O4 core nanoparticles via suitable core/shell ratio with particle size less than 100 nm. The core-shell nanoparticle size and the quality of coating influence the optical properties of the products. The UV-vis spectra of complete coated MgFe2O4-Au core-shell nanoparticles exhibit the absorption bands in the near-Infrared (NIR) region indicating high potential for therapeutic applications. Based on the magnetic property measurement, it was found that the obtained MgFe2O4-Au core-shell nanoparticles still exhibit superparamagnetism with lower saturation magnetization value, compared with MgFe2O4 core. Both of MgFe2O4 and MgFe2O4-Au core-shell also showed in vitro non-cytotoxicity to mouse areola fibroblast (L-929) cell line.

  3. Six Weeks of Core Stability Training Improves Landing Kinetics Among Female Capoeira Athletes: A Pilot Study

    PubMed Central

    Araujo, Simone; Cohen, Daniel; Hayes, Lawrence

    2015-01-01

    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

  4. 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

  5. A kinetic theory based numerical study of core collapse supernova dynamics

    NASA Astrophysics Data System (ADS)

    Strother, Terrance T.

    The explosion mechanism of core collapse supernovae remains an unsolved problem in astrophysics after many decades of theoretical and numerical study. The complex nature of this problem forces its consideration to rely heavily upon numerical simulations. Current state-of-the-art core collapse supernova simulations typically make use of hydrodynamic codes for the modeling of baryon dynamics coupled to a Boltzmann transport simulation for the neutrinos and other leptons. The results generated by such numerical simulations have given rise to the widely accepted notion that neutrino heating and convection are crucial for the explosion mechanism. However the precise roles that some factors such as neutrinos production and propagation, rotation, three-dimensional effects, the equation of state for asymmetric nuclear matter, general relativity, instabilities, magnetic fields, as well as others play in the explosion mechanism remain to be fully determined. In this work, we review sonic of the current methods used to simulate core collapse supernovae and the various scenarios that have been developed by numerical studies are discussed. Unlike most of the numerical simulations of core collapse supernovae, we employ a kinetic theory based approach that allows us to explicitly model the propagation of neutrinos and a full ensemble of nuclei. Both of these are significant advantages. The ability to explicitly model the propagation of neutrinos puts their treatment on equal footing with the modeling of baryon dynamics. No simplifying assumptions about the nature of neutrino-matter interactions need to be made and consequently our code is capable of producing output about the flow of neutrinos that most other simulations are inherently incapable of. Furthermore, neutrino flavor oscillations are readily incorporated with our approach. The ability to model the propagation of a full ensemble of nuclei is superior to the standard tracking of free baryons, alpha particles, and a

  6. Microstructural study of natural fractures in Cape Roberts Project 3 core, Western Ross Sea, Antarctica

    USGS Publications Warehouse

    Millan, C.; Wilson, T.; Paulsen, T.

    2007-01-01

    Microstructures in natural fractures in core recovered offshore from Cape Roberts, Ross Sea, Antarctica, provide new constraints on the relative timing of faulting and sedimentation in the Victoria Land Basin along the Transantarctic Mountain rift flank. This study characterizes the textures, fabrics and grain-scale structures from thin section analysis of samples of microfaults, veins, and clastic dikes. Microfaults are abundant and display two different types of textures, interpreted to record two different deformation modes: pre-lithification shearing and brittle faulting of cohesive sediment. Both clastic dikes and calcite veins commonly follow fault planes, indicating that injections of liquefied sediment and circulating fluids used pre-existing faults as conduits. The close association of clastic injections, diagenetic mineralization, and faulting indicates that faulting was synchronous with deposition in the rift basin

  7. Studies of lunar regolith dynamics using measurements of cosmogenic radionuclides in lunar rocks, soils and cores

    NASA Technical Reports Server (NTRS)

    Fruchter, J. S.; Reeves, J. H.; Evans, J. C.; Perkins, R. W.

    1982-01-01

    The present investigation is concerned with two types of measurements. The first deals with the use of Al-26 to define regolith gardening processes which have occurred in the upper portion of the lunar cores that were collected both by the deep drilling and drive tube operations. The second portion of the study involves the use of Mn-53 and Al-26 concentrations to determine the surface exposure histories of individual rocks over the past ten million years. It is found that during the past two million years, 15011 has had a history of simple gardening with an accumulation rate of 2 cm/m.y. The Apollo 15 Station 2 boulder appears to have been in place for about five million years. The 'shadowed' soil (75237) shows a shielding effect of about 40%. The Apollo 16 Station 9 boulder appears to have been in place for about four million years and thus is apparently not related to the South Ray Crater event.

  8. Alkyl-terminated Si(111) surfaces: A high-resolution, core level photoelectron spectroscopy study

    SciTech Connect

    Terry, J.; Linford, M.R.; Wigren, C.; Cao, R.; Pianetta, P.; Chidsey, C.E.

    1999-01-01

    The bonding of alkyl monolayers to Si(111) surfaces has been studied with high-resolution core level photoelectron spectroscopy (PES). Two very different wet-chemical methods have been used to prepare the alkyl monolayers: (i) Olefin insertion into the H{endash}Si bond of the H{endash}Si(111) surface, and (ii) replacement of Cl on the Cl{endash}Si(111) surface by an alkyl group from an alkyllithium reagent. In both cases, PES has revealed a C 1s component shifted to lower binding energy and a Si 2p component shifted to higher binding energy. Both components are attributed to the presence of a C{endash}Si bond at the interface. Along with photoelectron diffraction data [Appl. Phys. Lett. {bold 71}, 1056, (1997)], these data are used to show that these two synthetic methods can be used to functionalize the Si(111) surface. {copyright} {ital 1999 American Institute of Physics.}

  9. Graphyne core/shell nanoparticles: Monte Carlo study of thermal and magnetic properties

    NASA Astrophysics Data System (ADS)

    Drissi, L. B.; Zriouel, S.

    2016-05-01

    Magnetic properties and hysteresis behaviors of a graphyne core/shell nanoparticles are studied within the framework of Monte carlo calculations. We analyze in detail the ground-state phase diagrams in different planes. We examine the effects of the extrinsic and intrinsic parameters of the Hamiltonian on the magnetic and thermodynamic quantities of the system, namely, the total magnetization, its corresponding susceptibility, the hysteresis curves, and the compensation behavior that is of crucial importance for technological applications such as thermo-optical recording. A number of characteristic behaviors are found, such as the occurrence of one and two compensation temperatures and the existence of two new and non-classified types of compensation behavior in addition to the Q-, P- and N-types. Moreover, single and triple hysteresis loops, which exhibit different step effects and various shapes, are observed.

  10. Experimental and Analytic Study on the Core Bypass Flow in a Very High Temperature Reactor

    SciTech Connect

    Richard Schultz

    2012-04-01

    Core bypass flow has been one of key issues in the very high temperature reactor (VHTR) design for securing core thermal margins and achieving target temperatures at the core exit. The bypass flow in a prismatic VHTR core occurs through the control element holes and the radial and axial gaps between the graphite blocks for manufacturing and refueling tolerances. These gaps vary with the core life cycles because of the irradiation swelling/shrinkage characteristic of the graphite blocks such as fuel and reflector blocks, which are main components of a core's structure. Thus, the core bypass flow occurs in a complicated multidimensional way. The accurate prediction of this bypass flow and counter-measures to minimize it are thus of major importance in assuring core thermal margins and securing higher core efficiency. Even with this importance, there has not been much effort in quantifying and accurately modeling the effect of the core bypass flow. The main objectives of this project were to generate experimental data for validating the software to be used to calculate the bypass flow in a prismatic VHTR core, validate thermofluid analysis tools and their model improvements, and identify and assess measures for reducing the bypass flow. To achieve these objectives, tasks were defined to (1) design and construct experiments to generate validation data for software analysis tools, (2) determine the experimental conditions and define the measurement requirements and techniques, (3) generate and analyze the experimental data, (4) validate and improve the thermofluid analysis tools, and (5) identify measures to control the bypass flow and assess its performance in the experiment.

  11. 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

  12. Burn Survivors' Experience of Core Outcomes during Return to Life: a Qualitative Study

    PubMed Central

    Zamanzadeh, Vahid; Valizadeh, Leila; Lotfi, Mojgan; Salehi, Feridoon

    2014-01-01

    Introduction: Burn is one of the main and common health problems that face the victims with significant challenges in their lives. The main purpose of caring and rehabilitating these people is returning them to their previous life situation. Thus, the present study was conducted with the purpose of determining the experience of burn survivors with regard to returning to life in order to be able to obtain new concepts of acceptable implications in the present cultural and religious context. Methods: The present study is a qualitative study that was conducted using qualitative content analysis and in-depth unstructured interviews with 15 burn survivors in 2012 and 2013 in Tabriz. Results: During the process of qualitative analysis, the content of the category "balance", as the core essence of the experience of participants, was extracted according to three sub-categories: a- the physical integration (physiological stability, saving the affected limb), b-connecting to the life stream (self-care, getting accustomed, normalization), and c- return to the existence (sense of inner satisfaction and excellence). Conclusion: The results of this study confirmed the physical, psychological and social scales introduced by other studies. Also proposed the concept "return to the existence", that can be measured by the emergence of a sense of inner satisfaction and excellence in the individual, as one of the key and determinant scales in returning the victims of burn to life. PMID:25717453

  13. A Multi-Wavelength Study of Molecular Clouds and Starless Cores

    NASA Astrophysics Data System (ADS)

    Schnee, S. L.; Goodman, A. A.

    2005-12-01

    The physical properties of star-forming regions are best studied with a suite of measurements at a variety of wavelengths. My thesis is centered on combining several maps of the emission and/or extinction from dust with molecular line transition on scales as large as that of entire molecular clouds and as small as that of individual star-forming cores. As part of the COMPLETE Survey of Star-Forming Regions we have made a new set of dust temperature and column density maps for the Perseus, Ophiuchus and Serpens molecular clouds. Using the newly recalibrated IRAS data (IRIS) and 2MASS maps, we have determined the conversion from 100 micron optical depth to visual extinction, and found that this conversion is significantly different between clouds. In addition, we show that using IRAS maps to determine the column density of dust results in significant errors for AV > 1 due to temperature variations along the line of sight. The observed scatter between column density derived from pairs of emission maps and column density derived from the NIR colors of background stars can be reproduced without the inclusion of emission from transiently heated dust grains and without including the effects of variable dust emission properties. Using SCUBA and MAMBO maps of TMC-1C, a starless core in Taurus, we have mapped the dust temperature, column density, and emissivity spectral index at ˜ 14 arcsecond resolution. The density profile is consistent with that of a Bonnor-Ebert sphere, and the temperature varies from 7 to 12 K. By combining the dust emission maps with molecular line maps we show that TMC-1C is out of virial equilibrium and contracting at a rate slower than the sound speed.

  14. Ice core studies of anthropogenic sulfate and nitrate trends in the Arctic

    NASA Astrophysics Data System (ADS)

    Goto-Azuma, Kumiko; Koerner, Roy M.

    2001-03-01

    Ice core studies have shown that sulfate and nitrate concentrations in Arctic snow have increased significantly since the end of the 19th century due to the influx of anthropogenic pollutants transported from industrialized regions. Trends of increasing sulfate and nitrate concentrations in snow are evident in all the ice core data from Greenland, the Canadian Arctic, and Svalbard. Temporal patterns, however, show spatial variation. In the area around Dye 3, south Greenland, significant increases in sulfate are found beginning in the 1890s. Increases in nitrate began ˜50 years later. A similar pattern is seen at Penny Ice Cap, Baffin Island, in the Canadian low Arctic. In contrast, both sulfate and nitrate concentrations started to increase significantly in the 1940s on Agassiz Ice Cap, Ellesmere Island, in the Canadian high Arctic; and Snøfjellafonna, Svalbard. At Summit, central Greenland, and sites in north Greenland, sharp sulfate increases occurred at about the turn of the 20th century and again about 1940 or 1950, where the latter increase is the greater of the two. At these central and north Greenland sites, significant increases in nitrate began about 1940 or 1950. The difference between the magnitude and timing of increasing trends of the sulfate ions at these sites can be attributed to their having different source regions and pathways for these pollutant ions. The pollutant sources appear to be North America for south Greenland and Baffin Island, Eurasia, for Ellesmere Island and Svalbard, and both North America and Eurasia for central and north Greenland.

  15. Getting more from the core: studying mature root system traits in the field.

    NASA Astrophysics Data System (ADS)

    Wasson, Anton; Richards, Richard; Kirkegaard, John; Rebetzke, Greg; Watt, Michelle

    2015-04-01

    The productivity of existing agricultural land must be improved if global food requirements are to be met without agricultural land further encroaching on natural ecosystems degrading the services they provide. Better capture and use of the water and nutrients of the subsoil would improve the productivity and efficiency of many agricultural production systems and will also reduce risks of environmental damage (reducing leaching, eutrophication, and salinization). However in many agro-ecosystems subsoil resources are underutilised by crops, even where the crop would benefit from and can access them. Improved understanding of the development of root systems into subsoil may explain this perplexing phenomenon, but the technologies and approaches to characterise the root systems are lacking. Root systems have been neglected in cereal breeding efforts because they are difficult to work with, but, with many of the "easy" gains having been made, root systems are receiving increasing attention. Root system constraints can be limiting for water uptake and efficiency, even in high yielding environments. Pre-breeding efforts have focused on root traits in the laboratory, but these are not reflective of mature root systems in the field. We have reversed the approach, and have been developing the techniques necessary to phenotype roots in the field. Our studies have lead us to favour direct measures of root systems using soil coring, instead of indirect measures of root performance. We have been improving the throughput of soil coring and have developed a system that allowed us to identify genotypes with root traits that are superior to commercial varieties in wheat.

  16. A comparative theoretical study on core-hole excitation spectra of azafullerene and its derivatives

    SciTech Connect

    Deng, Yunfeng; Gao, Bin; Deng, Mingsen; Luo, Yi

    2014-03-28

    The core-hole excitation spectra—near-edge x-ray absorption spectroscopy (NEXAFS), x-ray emission spectroscopy (XES), and x-ray photoelectron spectroscopy (XPS) shake-up satellites have been simulated at the level of density functional theory for the azafullerene C{sub 59}N and its derivatives (C{sub 59}N){sup +}, C{sub 59}HN, (C{sub 59}N){sub 2}, and C{sub 59}N–C{sub 60}, in which the XPS shake-up satellites were simulated using our developed equivalent core hole Kohn-Sham (ECH-KS) density functional theory approach [B. Gao, Z. Wu, and Y. Luo, J. Chem. Phys. 128, 234704 (2008)] which aims for the study of XPS shake-up satellites of large-scale molecules. Our calculated spectra are generally in good agreement with available experimental results that validates the use of the ECH-KS method in the present work. The nitrogen K-edge NEXAFS, XES, and XPS shake-up satellites spectra in general can be used as fingerprints to distinguish the azafullerene C{sub 59}N and its different derivatives. Meanwhile, different carbon K-edge spectra could also provide detailed information of (local) electronic structures of different molecules. In particular, a peak (at around 284.5 eV) in the carbon K-edge NEXAFS spectrum of the heterodimer C{sub 59}N–C{sub 60} is confirmed to be related to the electron transfer from the C{sub 59}N part to the C{sub 60} part in this charge-transfer complex.

  17. Photoluminescence study of high density Si quantum dots with Ge core

    NASA Astrophysics Data System (ADS)

    Kondo, K.; Makihara, K.; Ikeda, M.; Miyazaki, S.

    2016-01-01

    Si quantum dots (Si-QDs) with Ge core were self-assembled on thermally grown SiO2 from alternate thermal decomposition of pure SiH4 and GeH4 diluted with He. When the sample was excited by the 979 nm line of a semiconductor laser, fairly broad photoluminescence (PL) spectra in the region of 0.6-0.8 eV were observed at room temperature. The observed PL spectra suggested that radiative recombination of photo-generated carriers through quantized states of Ge core is the dominant pathway for the emission from the dots, reflecting the type II energy band discontinuity between the Si clad and Ge core. We also found that P-δ doping to Ge core plays an important role in recombination through the quantized states in the valence band of Ge core and P donor levels.

  18. Outcome of ECT by Race in the CORE Multi-Site Study

    PubMed Central

    Williams, Mark; Rummans, Teresa; Sampson, Shirlene; Knapp, Rebecca; Mueller, Martina; Husain, Mustafa M.; Fink, Max; Rasmussen, Keith; O’Connor, Kevin; Smith, Glenn; Petrides, George; Kellner, Charles H.

    2014-01-01

    Objective The authors examine the differences in outcome between black and white patients receiving ECT as a part of the CORE multi-site study. Methods A total of 624 patients were enrolled in an NIMH-funded, randomized controlled ECT trial comparing the efficacy of continuation ECT versus continuation pharmacotherapy between 1997 and 2004. This analysis focuses on the 32 black and 483 white patients who participated in phase I of the study. The authors compared baseline demographic and clinical variables, and acute outcomes of these two groups. Results Compared to whites, far fewer blacks participated in the study. Those who did were less likely to have failed adequate medication trials and were more likely to have psychotic features. Their initial HAMD24 scores were higher than whites, and they showed a greater reduction in these HAMD24 scores by the end of the treatment period. While sample size limited the statistical significance of the findings, black patients also showed a higher rate of remission after an acute phase of ECT. Conclusions This study found that black and white patients with major depressive disorder had comparable outcomes. We also found that fewer black patients received ECT than whites, a difference that has been reported in other samples. PMID:18580553

  19. Getting to the Core: Using Digital Resources to Enhance Content-Based Literacy in the Social Studies

    ERIC Educational Resources Information Center

    Berson, Ilene R.; Berson, Michael J.

    2013-01-01

    With the implementation of the Common Core State Standards for English Language Arts and Literacy in History/Social Studies, Science, and Technical Subjects, teachers across the United States are expanding their integrated approach to social studies instruction and literacy studies. They are challenged to infuse text and narratives linked to…

  20. Turbulence coefficients and stability studies for the coaxial flow or dissimiliar fluids. [gaseous core nuclear reactors

    NASA Technical Reports Server (NTRS)

    Weinstein, H.; Lavan, Z.

    1975-01-01

    Analytical investigations of fluid dynamics problems of relevance to the gaseous core nuclear reactor program are presented. The vortex type flow which appears in the nuclear light bulb concept is analyzed along with the fluid flow in the fuel inlet region for the coaxial flow gaseous core nuclear reactor concept. The development of numerical methods for the solution of the Navier-Stokes equations for appropriate geometries is extended to the case of rotating flows and almost completes the gas core program requirements in this area. The investigations demonstrate that the conceptual design of the coaxial flow reactor needs further development.

  1. A comparative study of the impact properties of sandwich materials with different cores

    NASA Astrophysics Data System (ADS)

    Ramakrishnan, K. R.; Shankar, K.; Viot, P.; Guerard, S.

    2012-08-01

    Sandwich panels are made of two high strength skins bonded to either side of a light weight core and are used in applications where high stiffness combined with low structural weight is required. The purpose of this paper is to compare the mechanical response of several sandwich panels whose core materials are different. Sandwich panels with glass fibre-reinforced polymer face sheets were used, combined with five different cores; polystyrene foam, polypropylene honeycomb, two different density Balsa wood and Cork. All specimens were subjected to low velocity impact and their structural response (Force-displacement curves) were compared to quasistatic response of the panel tested using an hemispherical indenter.

  2. Paleomagnetic studies of Carboniferous and Permian in the U. K. Southern North Sea: Core orientation, paleocurrent analysis, and diagenetic application

    SciTech Connect

    Turner, P. ); Hartley, A.J. )

    1991-03-01

    The U.K. southern North Sea is a major gas province with production from Carboniferous and Permian reservoirs. It was a foreland basin in Carboniferous times uplifted to form a Lower Permian desert basin and subsequently deeply buried during the Mesozoic. Paleomagnetic methods have been used for burial analysis, core orientation, and paleocurrent studies. VRM is shown to be of only limited value for core orientation; problems relating to drilling effects and deflection by ChRM will be discussed. Detailed thermal demagnetization studies are most valuable. Blocking temperature spectra can be related to burial history curves, and ChRM directions isolated and compared with Carboniferous and Permian reference directions. ChRM is a valuable parameter for core orientation and thus paleocurrent studies. Examples will be shown from the Carboniferous and Lower Permian.

  3. Fractographic study of the behavior of different ceramic veneers on full coverage crowns in relation to supporting core materials

    PubMed Central

    Agustín-Panadero, Rubén; Román-Rodriguez, Juan L.; Solá-Ruíz, María F.; Granell-Ruíz, María; Fons-Font, Antonio

    2013-01-01

    Objectives: To observe porcelain veneer behavior of zirconia and metal-ceramic full coverage crowns when subjected to compression testing, comparing zirconia cores to metal cores. Study Design: The porcelain fracture surfaces of 120 full coverage crowns (60 with a metal core and 60 with a zirconia core) subjected to static load (compression) testing were analyzed. Image analysis was performed using macroscopic processing with 8x and 12x enlargement. Five samples from each group were prepared and underwent scanning electron microscope (SEM) analysis in order to make a fractographic study of fracture propagation in the contact area and composition analysis in the most significant areas of the specimen. Results: Statistically significant differences in fracture type (cohesive or adhesive) were found between the metal-ceramic and zirconia groups: the incidence of adhesive fracture was seen to be greater in metal-ceramic groups (92%) and cohesive fracture was more frequent in zirconium oxide groups (72%). The fracture propagation pattern was on the periphery of the contact area in the full coverage crown restorations selected for fractographic study. Conclusions: The greater frequency of cohesive fracture in restorations with zirconia cores indicates that their behavior is inadequate compared to metal-ceramic restorations and that further research is needed to improve their clinical performance. Key words:Zirconia, zirconium oxide, fractography, composition, porcelain veneers, fracture, cohesive, adhesive. PMID:24455092

  4. Preliminary Results of a Multi-Proxy Lake Sediment Core Study in East-Central France

    NASA Astrophysics Data System (ADS)

    Misner, T.; Meyers, S.; Rosenmeier, M.; Strano, S.; Straffin, E.

    2008-12-01

    This paper presents the preliminary results of a multi-proxy study of natural and human-induced changes in the Burgundian environment, as recorded in the sediment geochemistry of three small freshwater basins within the Arroux River Valley, east-central France. Accelerator mass spectrometry radiocarbon dates constrain the age of core material collected from the basins, and indicate that these mill and farm ponds were constructed by at least 1200 A.D. The pond sediments are predominantly massive, organic-rich muds that contain discrete sand and gravel lenses likely related to episodic flooding and/or basin drainage. In this study, continuous X-ray fluorescence (XRF) scanning is used to quantify bulk geochemical variability throughout the lake sediment cores, and to investigate specific elemental proxies for paleoenvironmental change (detrital flux, biogenic flux, and redox state). The high-resolution XRF data are supplemented by sediment magnetic susceptibility measurements, and organic matter concentration as determined by loss on ignition. These records demonstrate a general increase in detrital sediment input from 1200 to 1300 A.D., during a period of known regional agricultural expansion. We infer these changes to be the consequence of increased catchment soil erosion and material flux to the water bodies. The data also suggest changes in mill and farm pond primary productivity, also related to soil erosion and changing transport of soil nutrients to the basins. Near the onset of the Little Ice Age (ca. 1500 A.D.) pond productivity reductions are apparent, likely indicating colder climates. These mill and farm pond sedimentary archives, in conjunction with historic records, can be used to better understand past land management strategies. Furthermore, historically documented landscape changes can be examined within the context of prevailing climatic conditions over the last ~800 years in an effort to establish future best management practices and the most

  5. Composite Cores

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Spang & Company's new configuration of converter transformer cores is a composite of gapped and ungapped cores assembled together in concentric relationship. The net effect of the composite design is to combine the protection from saturation offered by the gapped core with the lower magnetizing requirement of the ungapped core. The uncut core functions under normal operating conditions and the cut core takes over during abnormal operation to prevent power surges and their potentially destructive effect on transistors. Principal customers are aerospace and defense manufacturers. Cores also have applicability in commercial products where precise power regulation is required, as in the power supplies for large mainframe computers.

  6. Ab Initio Study of 40Ca with an Importance Truncated No-Core Shell Model

    SciTech Connect

    Roth, R; Navratil, P

    2007-05-22

    We propose an importance truncation scheme for the no-core shell model, which enables converged calculations for nuclei well beyond the p-shell. It is based on an a priori measure for the importance of individual basis states constructed by means of many-body perturbation theory. Only the physically relevant states of the no-core model space are considered, which leads to a dramatic reduction of the basis dimension. We analyze the validity and efficiency of this truncation scheme using different realistic nucleon-nucleon interactions and compare to conventional no-core shell model calculations for {sup 4}He and {sup 16}O. Then, we present the first converged calculations for the ground state of {sup 40}Ca within no-core model spaces including up to 16{h_bar}{Omega}-excitations using realistic low-momentum interactions. The scheme is universal and can be easily applied to other quantum many-body problems.

  7. A first-principles core-level XPS study on the boron impurities in germanium crystal

    SciTech Connect

    Yamauchi, Jun; Yoshimoto, Yoshihide; Suwa, Yuji

    2013-12-04

    We systematically investigated the x-ray photoelectron spectroscopy (XPS) core-level shifts and formation energies of boron defects in germanium crystals and compared the results to those in silicon crystals. Both for XPS core-level shifts and formation energies, relationship between defects in Si and Ge is roughly linear. From the similarity in the formation energy, it is expected that the exotic clusters like icosahedral B12 exist in Ge as well as in Si.

  8. Perceived pros and cons of smoking and quitting in hard-core smokers: a focus group study

    PubMed Central

    2014-01-01

    Background In the last decade, so-called hard-core smokers have received increasing interest in research literature. For smokers in general, the study of perceived costs and benefits (or ‘pros and cons’) of smoking and quitting is of particular importance in predicting motivation to quit and actual quitting attempts. Therefore, this study aims to gain insight into the perceived pros and cons of smoking and quitting in hard-core smokers. Methods We conducted 11 focus group interviews among current hard-core smokers (n = 32) and former hard-core smokers (n = 31) in the Netherlands. Subsequently, each participant listed his or her main pros and cons in a questionnaire. We used a structural procedure to analyse the data obtained from the group interviews and from the questionnaires. Results Using the qualitative data of both the questionnaires and the transcripts, the perceived pros and cons of smoking and smoking cessation were grouped into 6 main categories: Finance, Health, Intrapersonal Processes, Social Environment, Physical Environment and Food and Weight. Conclusions Although the perceived pros and cons of smoking in hard-core smokers largely mirror the perceived pros and cons of quitting, there are some major differences with respect to weight, social integration, health of children and stress reduction, that should be taken into account in clinical settings and when developing interventions. Based on these findings we propose the ‘Distorted Mirror Hypothesis’. PMID:24548463

  9. A Numerical Study on the Effect of Facesheet-Core Disbonds on the Buckling Load of Curved Honeycomb Sandwich Panels

    NASA Technical Reports Server (NTRS)

    Pineda, Evan J.; Myers, David E.; Bednarcyk, Brett A.; Krivanek, Thomas M.

    2015-01-01

    A numerical study on the effect of facesheet-core disbonds on the post-buckling response of curved honeycomb sandwich panels is presented herein. This work was conducted as part of the development of a damage tolerance approach for the next-generation Space Launch System heavy lift vehicle payload fairing. As such, the study utilized full-scale fairing barrel segments as the structure of interest. The panels were composed of carbon fiber reinforced polymer facesheets and aluminum honeycomb core. The panels were analyzed numerically using the finite element method. Facesheet and core nodes in a predetermined circular region were detached to simulate a disbond induced via low-speed impact between the outer mold line facesheet and honeycomb core. Surface-to-surface contact in the disbonded region was invoked to prevent interpenetration of the facesheet and core elements. The diameter of this disbonded region was varied and the effect of the size of the disbond on the post-buckling response was observed. A significant change in the slope of the edge load-deflection response was used to determine the onset of global buckling and corresponding buckling load.

  10. THE EFFECT OF SELF-SET GRADE GOALS AND CORE SELF-EVALUATIONS ON ACADEMIC PERFORMANCE: A DIARY STUDY.

    PubMed

    Bipp, Tanja; Kleingeld, Ad; Van Den Tooren, Marieke; Schinkel, Sonja

    2015-12-01

    The aim of this diary study was to examine the effect of self-set grade goals and core self-evaluations on academic performance. Data were collected among 59 university students (M age = 18.4 yr., SD = 0.8) in a 2-wk. exam period on up to five exam days. Multilevel analyses revealed that the individual grade goals students set for their exams were positively related to the grades they obtained for these exams. However, the goal-performance relationship only applied to students scoring high on core self-evaluations. The results of this study contribute to the understanding of the effect of self-set grade goals and core self-evaluations on academic performance and imply important practical applications to enhance academic performance.

  11. X-ray study of mesomorphism of bent-core and chromonic mesogens

    NASA Astrophysics Data System (ADS)

    Joshi, Leela Pradhan

    The discovery of thermotropic biaxial nematic phase in bent-core mesogens, have engendered interest in these systems. Also, it undergoes optical switching about 100 times faster than conventional uniaxial nematic liquid crystal. Azo-substituted bent-core compounds, A131 and A103, were investigated as both offer an opportunity to observe their structures and phase transitions from the uniaxial nematic (Nu) to biaxial nematic (Nb) phase and from Nb to the underlying smectic-C (SmC) phase. Plank-like molecular systems are also expected to form Nb phase. Chromonic liquid crystals formed by aqueous solutions of plank-like dye molecules are interesting for their unique self-assembly and structural evolution. They have applications in optical element, coloring in food and textiles, and etc. Both systems were investigated with synchrotron x-ray scattering, polarizing optical microscopy, and differential scanning calorimetry. Temperature dependence of d-spacing and positional order correlations along the director clearly mark the phase boundaries where Nu-Nb transition was approximately 27° below the clearing point. Positional order correlation length of A131 increased from 1.5 in Nu to 3.3 molecular lengths in Nb phase, before it jumps by a factor of at least 5 in SmC phase. The lack of large discontinuous changes in the structural parameters and the subtle signatures in heat capacity establish the second order nature of Nu-Nb and Nb-SmC phase transitions. The chromonic system investigation results provide quantitative information of structural properties in nematic and columnar mesophases. We studied water solutions of (achiral) sunset yellow dye and (chiral and achiral) dihydrochloride salts of perylenebis-dicarboxydiimide. Positional order correlation lengths measurements, parallel and perpendicular to the aggregate axis, revealed that they increase with concentration and decrease with temperature. Temperature dependence of correlation lengths yielded the scission

  12. Study of muons near shower cores at sea level using the E594 neutrino detector

    NASA Technical Reports Server (NTRS)

    Goodman, J. A.; Gupta, S. C.; Freudenreich, H.; Sivaprasad, K.; Tonwar, S. C.; Yodh, G. B.; Ellsworth, R. W.; Goodman, M. C.; Bogert, D.; Burnstein, R.

    1985-01-01

    The E594 neutrino detector has been used to study the lateral distribution of muons of energy 3 GeV near shower cores. The detector consists of a 340 ton fine grain calorimeter with 400,000 cells of flash chamber and dimensions of 3.7 m x 20 m x 3.7 m (height). The average density in the calorimeter is 1.4 gm/sq cm, and the average Z is 21. The detector was triggered by four 0.6 sq m scintillators placed immediately on the top of the calorimeter. The trigger required at least two of these four counters. The accompanying extensive air showers (EAS) was sampled by 14 scintillation counters located up to 15 m from the calorimeter. Several off line cuts have been applied to the data. Demanding five particles in at least two of the trigger detectors, a total of 20 particles in all of them together, and an arrival angle for the shower 450 deg reduced the data sample to 11053 events. Of these in 4869 cases, a computer algorithm found at least three muons in the calorimeter.

  13. Parametric study of flow patterns behind the standing accretion shock wave for core-collapse supernovae

    SciTech Connect

    Iwakami, Wakana; Nagakura, Hiroki; Yamada, Shoichi

    2014-05-10

    In this study, we conduct three-dimensional hydrodynamic simulations systematically to investigate the flow patterns behind the accretion shock waves that are commonly formed in the post-bounce phase of core-collapse supernovae. Adding small perturbations to spherically symmetric, steady, shocked accretion flows, we compute the subsequent evolutions to find what flow pattern emerges as a consequence of hydrodynamical instabilities such as convection and standing accretion shock instability for different neutrino luminosities and mass accretion rates. Depending on these two controlling parameters, various flow patterns are indeed realized. We classify them into three basic patterns and two intermediate ones; the former includes sloshing motion (SL), spiral motion (SP), and multiple buoyant bubble formation (BB); the latter consists of spiral motion with buoyant-bubble formation (SPB) and spiral motion with pulsationally changing rotational velocities (SPP). Although the post-shock flow is highly chaotic, there is a clear trend in the pattern realization. The sloshing and spiral motions tend to be dominant for high accretion rates and low neutrino luminosities, and multiple buoyant bubbles prevail for low accretion rates and high neutrino luminosities. It is interesting that the dominant pattern is not always identical between the semi-nonlinear and nonlinear phases near the critical luminosity; the intermediate cases are realized in the latter case. Running several simulations with different random perturbations, we confirm that the realization of flow pattern is robust in most cases.

  14. Denitrification and photosynthesis in stream sediment studied with microsensor and whole-core techniques

    SciTech Connect

    Nielsen, L.P.; Christensen, P.B.; Revsbech, N.P.; Soerensen, J. )

    1990-07-01

    The effect of light on benthic photosynthesis, denitrification, and assimilation of NH{sub 4}{sup +} and NO{sub 3}{sup {minus}} in stream sediments was studied with whole-core techniques and with O{sub 2} and N{sub 2}O microsensors. Photosynthetic oxygen production increased the thickness of the aerobic surface layer from 1.5 mm in the dark to {approximately} 3.5 mm at a light intensity saturating photosynthesis. The O{sub 2} flux change concurrently from net uptake to net release and the overall rate of denitrification was reduced by 70%. Denitrification was always restricted to a narrow zone immediately below the aerobic-anaerobic interface. Calculated NO{sub 3}{sup {minus}} microprofiles showed that overall denitrification was primarily dependent on the thickness of the aerobic layer which acted as a barrier for diffusion of NO{sub 3}{sup {minus}} from the overlying water. In the light, algal NO{sub 3}{sup {minus}} assimilation could exceed NO{sub 3}{sup {minus}} consumption by denitrification when availability of NH{sub 4}{sup +} was low. Assimilation of NO{sub 3}{sup {minus}}, however, had no influence on the flux of NO{sub 3}{sup {minus}} to the denitrification zone, since assimilation occurred relatively close to the sediment surface.

  15. Numerical Models of Starburst Galaxies: A Study of Outflows and ISM Morphology in Galactic Cores

    NASA Astrophysics Data System (ADS)

    Tanner, Ryan; Cecil, G. N.; Heitsch, F.

    2014-01-01

    Starbursts and AGN winds in galaxy cores can produce large scale outflows. Whether any given outburst can create an outflow depends on several variables including the rate at which the energy is injected into the interstellar medium (ISM), the distribution of clouds with in the ISM, and the overall shape of the ISM. Previous simulations by Cooper et al. (2008) reproduce linear filaments like that in M 82, but were limited in the parameter space that they could explore. We have modified the public Athena hydro code (Stone et al. 2008) to greatly reduce the computation time of high resolution 3D simulations similar to Cooper et al. (2008) and to handle accurate gas cooling down to lower molecule-forming temperatures (10 K). We are exploring the parameter space of a galactic “blowout”, the origin and evolution of interesting ISM morphology such as the curved filamentary “towers” observed at the center of NGC 3079, and how different ISM morphologies may influence the outflow. These simulations are being compared with spectral imaging obtained with the Herschel space telescope to study the connection between regions of the cold neutral medium, warm neutral medium, and warm ionized medium. Those observations are being presented in another session of this AAS meeting. Our work is supported by NASA/Herschel and NC Space Grant funding.

  16. Nucleosome Core Particle Disassembly and Assembly Kinetics Studied Using Single-Molecule Fluorescence.

    PubMed

    Hazan, Noa Plavner; Tomov, Toma E; Tsukanov, Roman; Liber, Miran; Berger, Yaron; Masoud, Rula; Toth, Katalin; Langowski, Joerg; Nir, Eyal

    2015-10-20

    The stability of the nucleosome core particle (NCP) is believed to play a major role in regulation of gene expression. To understand the mechanisms that influence NCP stability, we studied stability and dissociation and association kinetics under different histone protein (NCP) and NaCl concentrations using single-pair Förster resonance energy transfer and alternating laser excitation techniques. The method enables distinction between folded, unfolded, and intermediate NCP states and enables measurements at picomolar to nanomolar NCP concentrations where dissociation and association reactions can be directly observed. We reproduced the previously observed nonmonotonic dependence of NCP stability on NaCl concentration, and we suggest that this rather unexpected behavior is a result of interplay between repulsive and attractive forces within positively charged histones and between the histones and the negatively charged DNA. Higher NaCl concentrations decrease the attractive force between the histone proteins and the DNA but also stabilize H2A/H2B histone dimers, and possibly (H3/H4)2 tetramers. An intermediate state in which one DNA arm is unwrapped, previously observed at high NaCl concentrations, is also explained by this salt-induced stabilization. The strong dependence of NCP stability on ion and histone concentrations, and possibly on other charged macromolecules, may play a role in chromosomal morphology.

  17. NON-EQUILIBRIUM CHEMISTRY OF DYNAMICALLY EVOLVING PRESTELLAR CORES. I. BASIC MAGNETIC AND NON-MAGNETIC MODELS AND PARAMETER STUDIES

    SciTech Connect

    Tassis, Konstantinos; Willacy, Karen; Yorke, Harold W.; Turner, Neal J.

    2012-07-01

    We combine dynamical and non-equilibrium chemical modeling of evolving prestellar molecular cloud cores and investigate the evolution of molecular abundances in the contracting core. We model both magnetic cores, with varying degrees of initial magnetic support, and non-magnetic cores, with varying collapse delay times. We explore, through a parameter study, the competing effects of various model parameters in the evolving molecular abundances, including the elemental C/O ratio, the temperature, and the cosmic-ray ionization rate. We find that different models show their largest quantitative differences at the center of the core, whereas the outer layers, which evolve slower, have abundances which are severely degenerate among different dynamical models. There is a large range of possible abundance values for different models at a fixed evolutionary stage (central density), which demonstrates the large potential of chemical differentiation in prestellar cores. However, degeneracies among different models, compounded with uncertainties induced by other model parameters, make it difficult to discriminate among dynamical models. To address these difficulties, we identify abundance ratios between particular molecules, the measurement of which would have maximal potential for discrimination among the different models examined here. In particular, we find that the ratios between NH{sub 3} and CO, NH{sub 2} and CO, and NH{sub 3} and HCO{sup +} are sensitive to the evolutionary timescale, and that the ratio between HCN and OH is sensitive to the C/O ratio. Finally, we demonstrate that measurements of the central deviation (central depletion or enhancement) of abundances of certain molecules are good indicators of the dynamics of the core.

  18. Deep Chandra study of the truncated cool core of the Ophiuchus cluster

    NASA Astrophysics Data System (ADS)

    Werner, N.; Zhuravleva, I.; Canning, R. E. A.; Allen, S. W.; King, A. L.; Sanders, J. S.; Simionescu, A.; Taylor, G. B.; Morris, R. G.; Fabian, A. C.

    2016-08-01

    We present the results of a deep Chandra observation of the Ophiuchus cluster, the second brightest galaxy cluster in the X-ray sky. The cluster hosts a truncated cool core, with a temperature increasing from kT ˜ 1 keV in the core to kT ˜ 9 keV at r ˜ 30 kpc. Beyond r ˜ 30 kpc, the intracluster medium (ICM) appears remarkably isothermal. The core is dynamically disturbed with multiple sloshing-induced cold fronts, with indications for both Rayleigh-Taylor and Kelvin-Helmholtz instabilities. The residual image reveals a likely subcluster south of the core at the projected distance of r ˜ 280 kpc. The cluster also harbours a likely radio phoenix, a source revived by adiabatic compression by gas motions in the ICM. Even though the Ophiuchus cluster is strongly dynamically active, the amplitude of density fluctuations outside of the cooling core is low, indicating velocities smaller than ˜100 km s-1. The density fluctuations might be damped by thermal conduction in the hot and remarkably isothermal ICM, resulting in our underestimate of gas velocities. We find a surprising, sharp surface brightness discontinuity, that is curved away from the core, at r ˜ 120 kpc to the south-east of the cluster centre. We conclude that this feature is most likely due to gas dynamics associated with a merger. The cooling core lacks any observable X-ray cavities and the active galactic nucleus (AGN) only displays weak, point-like radio emission, lacking lobes or jets. The lack of strong AGN activity may be due to the bulk of the cooling taking place offset from the central supermassive black hole.

  19. Comparative evaluation of shear bond strength of three resin based dual-cure core build-up materials: An In-vitro study

    PubMed Central

    Jain, Gaurav; Narad, Aditi; Boruah, Lalit C.; Rajkumar, Balakrishnan

    2015-01-01

    Aim: The in-vitro study compared the shear bond strength (SBS) of three recently introduced dual-cure resin based core build-up materials namely ParaCore, FluoroCore, and MultiCore. Materials and Methods: One hundred twenty extracted permanent human mandibular molar teeth were taken and sectioned horizontally beneath the dentinoenamel junction to expose the coronal dentin. The specimens obtained were divided into three main groups based on the materials used and then further divided into four sub-groups based on time interval with ten samples each. The dentin surface was treated with the respective adhesives of the groups and then bulk filled with core build-up materials. The attained samples were than subjected to shear loading in Instron Universal Testing Machine. The data were tabulated and statistically analyzed using analysis of variance (ANOVA), Tukey's HSD, and Levene's test. Results: The mean SBS was highest in MultiCore at all time periods as compared to FluoroCore and ParaCore and was also higher at 48 h thermocycling in all three groups studied. Conclusion: MultiCore dual-cure resin based core build-up material showed the highest mean SBS as compared to FluoroCore and ParaCore. SBS was not negatively affected by thermocycling. PMID:26180422

  20. Development of a new academic digital library: a study of usage data of a core medical electronic journal collection

    PubMed Central

    Shearer, Barbara S.; Klatt, Carolyn; Nagy, Suzanne P.

    2009-01-01

    Objectives: The current study evaluates the results of a previously reported method for creating a core medical electronic journal collection for a new medical school library, validates the core collection created specifically to meet the needs of the new school, and identifies strategies for making cost-effective e-journal selection decisions. Methods: Usage data were extracted for four e-journal packages (Blackwell-Synergy, Cell Press, Lippincott Williams & Wilkins, and ScienceDirect). Usage was correlated with weighted point values assigned to a core list of journal titles, and each package was evaluated for relevancy and cost-effectiveness to the Florida State University College of Medicine (FSU COM) population. Results: The results indicated that the development of the core list was a valid method for creating a new twenty-first century, community-based medical school library. Thirty-seven journals are identified for addition to the FSU COM core list based on use by the COM, and areas of overlapping research interests between the university and the COM are identified based on use of specific journals by each population. Conclusions: The collection development approach that evolved at the FSU COM library was useful during the initial stages of identifying and evaluating journal selections and in assessing the relative value of a particular journal package for the FSU COM after the school was established. PMID:19404499

  1. Study on core radius minimization for long life Pb-Bi cooled CANDLE burnup scheme based fast reactor

    NASA Astrophysics Data System (ADS)

    Afifah, Maryam; Miura, Ryosuke; Su'ud, Zaki; Takaki, Naoyuki; Sekimoto, H.

    2015-09-01

    Fast Breeder Reactor had been interested to be developed over the world because it inexhaustible source energy, one of those is CANDLE reactor which is have strategy in burn-up scheme, need not control roads for control burn-up, have a constant core characteristics during energy production and don't need fuel shuffling. The calculation was made by basic reactor analysis which use Sodium coolant geometry core parameter as a reference core to study on minimum core reactor radius of CANDLE for long life Pb-Bi cooled, also want to perform pure coolant effect comparison between LBE and sodium in a same geometry design. The result show that the minimum core radius of Lead Bismuth cooled CANDLE is 100 cm and 500 MWth thermal output. Lead-Bismuth coolant for CANDLE reactor enable to reduce much reactor size and have a better void coefficient than Sodium cooled as the most coolant for FBR, then we will have a good point in safety analysis.

  2. A finite element study of teeth restored with post and core: Effect of design, material, and ferrule

    PubMed Central

    Upadhyaya, Viram; Bhargava, Akshay; Parkash, Hari; Chittaranjan, B.; Kumar, Vivek

    2016-01-01

    Background: Different postdesigns and materials are available; however, no consensus exists regarding superiority for stress distribution. The aim of this study was to evaluate the effect of design and material of post with or without ferrule on stress distribution using finite element analysis. Materials and Methods: A total of 12 three-dimensional (3D) axisymmetric models of postretained central incisors were made: Six with ferrule design and six without it. Three of these six models had tapered posts, and three had parallel posts. The materials tested were titanium post with a composite resin core, nickel chromium cast post and core, and fiber reinforced composite (FRC) post with a composite resin core. The stress analysis was done using ANSYS software. The load of 100 N at an angle of 45΀ was applied 2 mm cervical to incisal edge on the palatal surface and results were analyzed using 3D von Mises criteria. Results: The highest amount of stress was in the cervical region. Overall, the stress in the tapered postsystem was more than the parallel one. FRC post and composite resin core recorded minimal stresses within the post but the stresses transmitted to cervical dentin were more as compared to other systems. Minimal stresses in cervical dentine were observed where the remaining coronal dentin was strengthen by ferrule. Conclusion: A rigid material with high modulus of elasticity for post and core system creates most uniform stress distribution pattern. Ferrule provides uniform distribution of stresses and decreases the cervical stresses. PMID:27274343

  3. Structural and electronic properties of CdS/ZnS core/shell nanowires: A first-principles study

    NASA Astrophysics Data System (ADS)

    Kim, Hyo Seok; Kim, Yong-Hoon

    2015-03-01

    Carrying out density functional theory (DFT) calculation, we studied the relative effects of quantum confinement and strain on the electronic structures of II-IV semiconductor compounds with a large lattice-mismatch, CdS and ZnS, in the core/shell nanowire geometry. We considered different core radii and shell thickness of the CdS/ZnS core/shell nanowire, different surface facets, and various defects in the core/shell interface and surface regions. To properly describe the band level alignment at the core/shell boundary, we adopted the self-interaction correction (SIC)-DFT scheme. Implications of our findings in the context of device applications will be also discussed. This work was supported by the Basic Science Research Grant (No. 2012R1A1A2044793), Global Frontier Program (No. 2013-073298), and Nano-Material Technology Development Program (2012M3A7B4049888) of the National Research Foundation funded by the Ministry of Education, Science and Technology of Korea. Corresponding author

  4. Evaluation of shear bond strength between zirconia core and ceramic veneers fabricated by pressing and layering techniques: In vitro study

    PubMed Central

    Subash, M.; Vijitha, D.; Deb, Saikat; Satish, A.; Mahendirakumar, N.

    2015-01-01

    Statement of Problem: Although ceramic veneered on to zirconia core have been in use for quite some time, information regarding the comparative evaluation of the Shear bond strength of Pressable & Layered ceramic veneered on to zirconia core is limited. Purpose of study: To evaluate the shear bond strength of zirconia core and ceramic veneer fabricated by two different techniques, Layering (Noritake CZR) and Pressing (Noritake, CZR Press). Materials and Method: 20 samples of zirconia blocks were fabricated and the samples were divided into group A & B. Group A - Ceramic Veneered over zirconia core by pressing using Noritake CZR Press. Group B - Ceramic Veneered over zirconia core by layering using Noritake CZR. The veneered specimens were mounted on to the center of a PVC tube using self-cure acrylic resin leaving 3 mm of the veneered surface exposed as cantilever. Using a Universal testing machine the blocks were loaded up to failure. Result: The results were tabulated by using independent samples t-test. The mean shear bond strength for Pressed specimens was 12.458 ± 1.63(S.D) MPa and for layered specimens was 8.458 ± 0.845(S.D) MPa. Conclusion: Pressed specimens performed significantly better than the layered specimen with a P value 0.001. Clinicians and dental laboratory technicians should consider the use of pressed ceramics as an alternative to traditional layering procedures to reduce the chances of chipping or de-lamination of ceramics PMID:26538929

  5. Study on core radius minimization for long life Pb-Bi cooled CANDLE burnup scheme based fast reactor

    SciTech Connect

    Afifah, Maryam Su’ud, Zaki; Miura, Ryosuke; Takaki, Naoyuki; Sekimoto, H.

    2015-09-30

    Fast Breeder Reactor had been interested to be developed over the world because it inexhaustible source energy, one of those is CANDLE reactor which is have strategy in burn-up scheme, need not control roads for control burn-up, have a constant core characteristics during energy production and don’t need fuel shuffling. The calculation was made by basic reactor analysis which use Sodium coolant geometry core parameter as a reference core to study on minimum core reactor radius of CANDLE for long life Pb-Bi cooled, also want to perform pure coolant effect comparison between LBE and sodium in a same geometry design. The result show that the minimum core radius of Lead Bismuth cooled CANDLE is 100 cm and 500 MWth thermal output. Lead-Bismuth coolant for CANDLE reactor enable to reduce much reactor size and have a better void coefficient than Sodium cooled as the most coolant for FBR, then we will have a good point in safety analysis.

  6. ELECTROCHEMICAL CORROSION STUDIES FOR TANK 241-AN-107 CORE 309 SEGMENTS 21R1 & 21R2

    SciTech Connect

    DUNCAN JB

    2007-11-13

    Liquid waste in tank 241-AN-107 is below Technical Safety Requirements Administrative Control 5.16 (AC 5.16) limits. Electrochemical corrosion testing was performed on Core 309, Segments 21R1 and 21R2, to provide information on the conductivity and corrosive tendencies of the tank saltcake and interstitial liquid. This report describes data obtained under the execution of RPP-PLAN-29001, 'Electrochemical Corrosion Studies for Tank 241-AN-107 Core 309, Segments 21R1 and 21R2'. Analytical results are presented that show supernatant was within the limits while the interstitial liquid remained below the limits for the analytical cores. Applicable AC 5.16 chemistry control limits for AN-107 are presented.

  7. Protecting core networks with dual-homing: A study on enhanced network availability, resource efficiency, and energy-savings

    NASA Astrophysics Data System (ADS)

    Abeywickrama, Sandu; Furdek, Marija; Monti, Paolo; Wosinska, Lena; Wong, Elaine

    2016-12-01

    Core network survivability affects the reliability performance of telecommunication networks and remains one of the most important network design considerations. This paper critically examines the benefits arising from utilizing dual-homing in the optical access networks to provide resource-efficient protection against link and node failures in the optical core segment. Four novel, heuristic-based RWA algorithms that provide dedicated path protection in networks with dual-homing are proposed and studied. These algorithms protect against different failure scenarios (i.e. single link or node failures) and are implemented with different optimization objectives (i.e., minimization of wavelength usage and path length). Results obtained through simulations and comparison with baseline architectures indicate that exploiting dual-homed architecture in the access segment can bring significant improvements in terms of core network resource usage, connection availability, and power consumption.

  8. Models of molecular cloud cores. II. Multitransition study of CS-34

    SciTech Connect

    Mundy, L.G.; Evans, N.J.,II; Snell, R.L.; Goldsmith, P.F.; Bally, J.

    1986-07-01

    The dense cores embedded in the M17, S140 and NGC 2024 molecular clouds are mapped in the J = 5-4, J = 3-2, and J = 2-1 transitions of CS-34, and these lines are found to be a factor of 3-4 weaker, and 25 percent narrower, than the CS lines mapped in these cores by Snell et al. (1984). The data are well fitted by spherical LGV models for the excitation, and the excellent correlation between the CS-34 and CS column densities corroborates the absence of a systematic increase in the gas density with decreasing core radius found by Snell et al. Though the CS/CS-34 column density ratio is 9-17, rather than the terrestrial value of 22.5, the column density relationship is linear. The data support of a clump model in which the column density distribution in the core is determined by the volume filling factor of clumps with high, fairly uniform gas density, and it is suggested that the dense gas in the data represents the dominant component of the core gas. 22 references.

  9. Synthesis and characterization of core-shell acrylate based latex and study of its reactive blends.

    PubMed

    Liu, Xiang; Fan, Xiao-Dong; Tang, Min-Feng; Nie, Ying

    2008-03-01

    Techniques in resin blending are simple and efficient method for improving the properties of polymers, and have been used widely in polymer modification field. However, polymer latex blends such as the combination of latexes, especially the latexes with water-soluble polymers, were rarely reported. Here, we report a core-shell composite latex synthesized using methyl methacrylate (MMA), butyl acrylate (BA), 2-ethylhexyl acrylate (EHA) and glycidyl methacrylate (GMA) as monomers and ammonium persulfate and sodium bisulfite redox system as the initiator. Two stages seeded semi-continuous emulsion polymerization were employed for constructing a core-shell structure with P(MMA-co-BA) component as the core and P(EHA-co-GMA) component as the shell. Results of Transmission Electron Microscopy (TEM) and Dynamics Light Scattering (DLS) tests confirmed that the particles obtained are indeed possessing a desired core-shell structural character. Stable reactive latex blends were prepared by adding the latex with waterborne melamine-formaldehyde resin (MF) or urea-formaldehyde resin (UF). It was found that the glass transition temperature, the mechanical strength and the hygroscopic property of films cast from the latex blends present marked enhancements under higher thermal treatment temperature. It was revealed that the physical properties of chemically reactive latexes with core-shell structure could be altered via the change of crosslinking density both from the addition of crosslinkers and the thermal treatment.

  10. Synthesis and Characterization of Core-Shell Acrylate Based Latex and Study of Its Reactive Blends

    PubMed Central

    Liu, Xiang; Fan, Xiao-Dong; Tang, Min-Feng; Nie, Ying

    2008-01-01

    Techniques in resin blending are simple and efficient method for improving the properties of polymers, and have been used widely in polymer modification field. However, polymer latex blends such as the combination of latexes, especially the latexes with water-soluble polymers, were rarely reported. Here, we report a core-shell composite latex synthesized using methyl methacrylate (MMA), butyl acrylate (BA), 2-ethylhexyl acrylate (EHA) and glycidyl methacrylate (GMA) as monomers and ammonium persulfate and sodium bisulfite redox system as the initiator. Two stages seeded semi-continuous emulsion polymerization were employed for constructing a core-shell structure with P(MMA-co-BA) component as the core and P(EHA-co-GMA) component as the shell. Results of Transmission Electron Microscopy (TEM) and Dynamics Light Scattering (DLS) tests confirmed that the particles obtained are indeed possessing a desired core-shell structural character. Stable reactive latex blends were prepared by adding the latex with waterborne melamine-formaldehyde resin (MF) or urea-formaldehyde resin (UF). It was found that the glass transition temperature, the mechanical strength and the hygroscopic property of films cast from the latex blends present marked enhancements under higher thermal treatment temperature. It was revealed that the physical properties of chemically reactive latexes with core-shell structure could be altered via the change of crosslinking density both from the addition of crosslinkers and the thermal treatment. PMID:19325753

  11. Image guided versus palpation guided core needle biopsy of palpable breast masses: a prospective study

    PubMed Central

    Hari, Smriti; Kumari, Swati; Srivastava, Anurag; Thulkar, Sanjay; Mathur, Sandeep; Veedu, Prasad Thotton

    2016-01-01

    Background & objectives: Biopsy of palpable breast masses can be performed manually by palpation guidance or under imaging guidance. Based on retrospective studies, image guided biopsy is considered more accurate than palpation guided breast biopsy; however, these techniques have not been compared prospectively. We conducted this prospective study to verify the superiority and determine the size of beneficial effect of image guided biopsy over palpation guided biopsy. Methods: Over a period of 18 months, 36 patients each with palpable breast masses were randomized into palpation guided and image guided breast biopsy arms. Ultrasound was used for image guidance in 33 patients and mammographic (stereotactic) guidance in three patients. All biopsies were performed using 14 gauge automated core biopsy needles. Inconclusive, suspicious or imaging-histologic discordant biopsies were repeated. Results: Malignancy was found in 30 of 36 women in palpation guided biopsy arm and 27 of 36 women in image guided biopsy arm. Palpation guided biopsy had sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 46.7, 100, 100, 27.3 per cent, respectively, for diagnosing breast cancer. Nineteen of 36 women (52.8%) required repeat biopsy because of inadequate samples (7 of 19), suspicious findings (2 of 19) or imaging-histologic discordance (10 of 19). On repeat biopsy, malignancy was found in all cases of imaging-histologic discordance. Image guided biopsy had 96.3 per cent sensitivity and 100 per cent specificity. There was no case of inadequate sample or imaging-histologic discordance with image guided biopsy. Interpretation & conclusions: Our results showed that in palpable breast masses, image guided biopsy was superior to palpation guided biopsy in terms of sensitivity, false negative rate and repeat biopsy rates. PMID:27488003

  12. Core to Atmosphere Exploration of Ice Giants: A Uranus Mission Concept Study

    NASA Astrophysics Data System (ADS)

    Jensema, R. J.; Arias-Young, T. M.; Wilkins, A. N.; Ermakov, A.; Bennett, C.; Dietrich, A.; Hemingway, D.; Klein, V.; Mane, P.; Marr, K. D.; Masterson, J.; Siegel, V.; Stober, K. J.; Talpe, M.; Vines, S. K.; Wetteland, C. J.

    2014-12-01

    Ice giants remain largely unexplored, as their large distance from the Sun limits both Earth-based observations and spacecraft visits. The significant occurrence of ice giant-sized planets among detected exoplanets presents an impetus to study Uranus to understand planetary formation, dynamics, and evolution. In addition, Uranus is also uniquely interesting, given the large inclination of its rotation axis and magnetospheric configuration. In this work, we design a mission concept that aims to maximize scientific return by measuring Uranus' chemical composition, internal structure, and magnetosphere, the first two being primary indicators of ice giant formation mechanisms. For this study, we analyze the trade space for a Uranus mission constrained by a cost cap of $1B. We discuss the decision making processes behind our choices of the science priorities, instrument suite and orbital configuration. Trade space decisions include a strong onboard instrument suite in lieu of a descent probe, an orbiter instead of a flyby mission, and design constraints on the power and propulsion systems. The mission, CAELUS (Core and Atmospheric Evolution Laboratory for Uranus Science), is designed for an August 2023 launch. Following a 14-year cruise with multiple planetary gravity assists, the spacecraft would begin its science mission, which consists of a series of ten 30-day near-polar orbits around Uranus. The instrument suite would consist of a microwave radiometer, Doppler seismometer, magnetometer, and UV spectrometer. These four instruments, along with a high-gain antenna capable of gravity science, would provide a comprehensive science return that meets the bulk of the scientific objectives of the 2013 NRC Planetary Science Decadal Survey for ice giants, most notably those regarding the chemical composition, interior structure, and dynamo of Uranus. This mission concept was created as part of an educational exercise for the 2014 Planetary Science Summer School at the Jet

  13. Diffuse optical spectroscopy measurements of healing in breast tissue after core biopsy: case study

    PubMed Central

    Tanamai, Wendy; Chen, Cynthia; Siavoshi, Sara; Cerussi, Albert; Hsiang, David; Butler, John; Tromberg, Bruce

    2010-01-01

    Diffuse optical spectroscopy (DOS) has been used to monitor and predict the effects of neoadjuvant (i.e., presurgical) chemotherapy in breast cancer patients in several pilot studies. Because patients with suspected breast cancers undergo biopsy prior to treatment, it is important to understand how biopsy trauma influences DOS measurements in the breast. The goal of this study was to measure the effects of a standard core breast biopsy on DOS measurements of tissue deoxyhemoglobin, hemoglobin, water, and bulk lipid concentrations. We serially monitored postbiopsy effects in the breast tissue in a single subject (31-year-old premenopausal female) with a 37×18×20 mm fibroadenoma. A baseline measurement and eight weekly postbiopsy measurements were taken with a handheld DOS imaging instrument. Our instrument used frequency domain photon migration combined with broadband steady-state spectroscopy to characterize tissues via quantitative measurements of tissue absorption and reduced scattering coefficients from 650 to 1000 nm. The concentrations of significant near-infrared (NIR) absorbers were mapped within a 50 cm2 area over the biopsied region. A 2-D image of a contrast function called the tissue optical index (TOI=deoxyhemoglobin×water/bulk lipid) was generated and revealed that a minimum of 14 days postbiopsy was required to return TOI levels in the biopsied area to their prebiopsy levels. Changes in the TOI images of the fibroadenoma also reflected the progression of the patient’s menstrual cycle. DOS could therefore be useful in evaluating both wound-healing response and the effects of hormone and hormonal therapies in vivo. PMID:19256712

  14. Professional Development for Promoting 21st Century Skills and Common Core State Standards in Foreign Language and Social Studies Classrooms

    ERIC Educational Resources Information Center

    Beriswill, Joanne Elizabeth; Bracey, Pamela Scott; Sherman-Morris, Kathleen; Huang, Kun; Lee, Sang Joon

    2016-01-01

    To help satisfy the pressing need for technology-related professional development for in-service teachers, the Global Academic Essentials Teacher Institute (GAETI) was implemented to provide in-service foreign language and social studies teachers with content, pedagogy, and technology explorations centered on the teaching of the Common Core State…

  15. The Common Core State Standards: An Opportunity to Enhance Formative Assessment in History/Social Studies Classrooms

    ERIC Educational Resources Information Center

    Ateh, Comfort M.; Wyngowski, Aaron J.

    2015-01-01

    This article discusses the opportunity that the Common Core State Standards (CCSS) present for enhancing formative assessment (FA) in history and social studies classrooms. There is evidence that FA can enhance learning for students if implemented well. Unfortunately, teachers continue to be challenged in implementing FA in their classrooms. We…

  16. Transitioning to the Common Core State Standards for Mathematics: A Mixed Methods Study of Elementary Teachers' Experiences and Perspectives

    ERIC Educational Resources Information Center

    Swars, Susan Lee; Chestnutt, Cliff

    2016-01-01

    This mixed methods study explored elementary teachers' (n = 73) experiences with and perspectives on the recently implemented Common Core State Standards for Mathematics (CCSS-Mathematics) at a high-needs, urban school. Analysis of the survey, questionnaire, and interview data reveals the findings cluster around: familiarity with and preparation…

  17. Common Core State Standards for English Language Arts & Literacy in History/Social Studies, Science, and Technical Subjects

    ERIC Educational Resources Information Center

    Common Core State Standards Initiative, 2010

    2010-01-01

    The Common Core State Standards for English Language Arts & Literacy in History/Social Studies, Science, and Technical Subjects ("the Standards") are the culmination of an extended, broad-based effort to fulfill the charge issued by the states to create the next generation of K-12 standards in order to help ensure that all students are college and…

  18. Design Study for a Low-Enriched Uranium Core for the High Flux Isotope Reactor, Annual Report for FY 2006

    SciTech Connect

    Primm, R. T.; Ellis, R. J.; Gehin, J. C.; Clarno, K. T.; Williams, K. A.; Moses, D. L.

    2006-11-01

    Neutronics and thermal-hydraulics studies show that, for equivalent operating power [85 MW(t)], a low-enriched uranium (LEU) fuel cycle based on uranium-10 wt % molybdenum (U-10Mo) metal foil with radially, “continuously graded” fuel meat thickness results in a 15% reduction in peak thermal flux in the beryllium reflector of the High Flux Isotope Reactor (HFIR) as compared to the current highly enriched uranium (HEU) cycle. The uranium-235 content of the LEU core is almost twice the amount of the HEU core when the length of the fuel cycle is kept the same for both fuels. Because the uranium-238 content of an LEU core is a factor of 4 greater than the uranium-235 content, the LEU HFIR core would weigh 30% more than the HEU core. A minimum U-10Mo foil thickness of 84 μm is required to compensate for power peaking in the LEU core although this value could be increased significantly without much penalty. The maximum U-10Mo foil thickness is 457μm. Annual plutonium production from fueling the HFIR with LEU is predicted to be 2 kg. For dispersion fuels, the operating power for HFIR would be reduced considerably below 85 MW due to thermal considerations and due to the requirement of a 26-d fuel cycle. If an acceptable fuel can be developed, it is estimated that $140 M would be required to implement the conversion of the HFIR site at Oak Ridge National Laboratory from an HEU fuel cycle to an LEU fuel cycle. To complete the conversion by fiscal year 2014 would require that all fuel development and qualification be completed by the end of fiscal year 2009. Technological development areas that could increase the operating power of HFIR are identified as areas for study in the future.

  19. Cotton Valley Sandstone of East Texas: a log-core study

    SciTech Connect

    Wilson, D.A.; Hensel, W.M. Jr.

    1984-09-01

    A comparison of calculations of various reservoir parameters, from logs and cores, provides guidelines for understanding reservoir evaluation in the Cotton Valley Sandstone of east Texas. The cores and logs are from the Carthage field area in Panola County. In these rocks, grain size distribution and the degree of shaliness, in addition to porosity, control permeability and irreducible water saturation. Clays in the Cotton Valley are mainly illite and chlorite. Cementation factor and saturation exponent values vary on a bed-by-bed basis; however, values of a = 1, m = 1.83, and an average value of n = 1.89 are acceptable for general evaluations. Sun's BITRI program was used to compute values for lithology porosity and water saturation, in good agreement with standard core and x-ray analysis. Cotton Valley Sandstone intervals with porosities less than 4% appear to be nonproductive.

  20. [Study on a new urine analysis core module based on semi-reflection mirror].

    PubMed

    Chen, Longcong; Liu, Gaiqin; Hu, Nan; Zhang, Ruiying; Jiang, Qifeng; Gao, Bin; Xiong, Xingliang

    2014-12-01

    A new urine analysis core module based on high performance 32-bit microprocessor and high precision color sensor was presented. A novel optical structure and a specific circuit were applied to improve measurement precision and temperature was used to compensate for results in this core module. The information of urine test peice, such as all original data and color RGB value, reflectivity, semi-quantitative level, etc. can be output. The results showed that the measuring precision was about 95% or above with ideal stability and reliability using this presented core module, which can be conveniently applied in various urine analyzers, and can greatly decrease the cost of urine analyzers in development and production.

  1. Comparative dissolution study of drug and inert isomalt based core material from layered pellets.

    PubMed

    Kállai-Szabó, Nikolett; Luhn, Oliver; Bernard, Joerg; Kállai-Szabó, Barnabás; Zelkó, Romána; Antal, István

    2014-09-01

    Layered and coated pellets were formulated to control the release of the diclofenac sodium selected as model drug. A highly water soluble isomalt inert pellet core material was used to osmotically modulate the drug release through the swellable polyvinyl acetate coating layer. Image analysis was applied to determine the shape parameters and the swelling behavior of the pellets. UV-spectroscopy and liquid chromatography with refractive index detection were applied to measure the concentration of the model drug and the core materials. Simultaneous dissolution of both the diclofenac sodium and isomalt was observed. Relationship was found between the dissolution profile of the drug and the core material which linear correlation was independent on the coating level. The latter enables the modulation of drug release beside the permeability control of the swelled coating polymer.

  2. Computational Study on the Steady-state Impedance of Saturated-core Superconducting Fault Current Limiter

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Tang, Y.; Liang, S.; Ren, L.; Wang, Z.; Xu, Y.

    This paper presents the electromagnetic analysis of a high voltage saturated-core superconducting fault current limiter (SCSFCL). The numerical analyses of a three-dimensional (3D) model is shown, and the specific parameters are given. The model focus on the steady-state impedance of the limiter when connected to the power grid. It analyzed the dependence of steady-state impedance on the AC coil current, and the relationship between oil gap and coil inductance. The results suggest that, adding oil gap between slice of silicon steel can reduce the core cross-section, restrain the ultraharmonic and decrease the steady-state impedance. As the core cross-section of AC limb decreased from 4344 cm2 to 3983 cm2, the total harmonic distortion for voltage decreased from 2.4% to 1.8%, and the impedance decreased from 1.082 Ω to 1.069 Ω(Idc=400A,Iac=1296A).

  3. Water Stable Isotopes: Atmospheric Composition and Applications in Polar Ice Core Studies

    NASA Astrophysics Data System (ADS)

    Jouzel, J.

    2003-12-01

    large-scale properties. First, there is no clear relationship between δp and the temperature of the site in tropical and equatorial regions. There, δp is more significantly influenced by precipitation amount. Second (see Figure 2), δD and δ18O are linearly related to each other throughout the world with a slope of ˜8 and a deuterium excess (d=δD-8δ18O) of ˜10‰ (Craig, 1961; Dansgaard, 1964). Although there has been a lot of potential interest in characterizing modifications in precipitation patterns such as those linked with changes in moonsonal activity or in the El Niño Southern Oscillation, the first property has, up to now, only been exploited in a very limited number of studies. In contrast, the fact that the deuterium excess of a precipitation is influenced by the conditions prevailing in the oceanic moisture source region (temperature, relative humidity, and, to a lesser degree, wind speed) is now widely used to reconstruct the changes in the temperature of the evaporative source, Tw. (6K)Figure 2. Annual δD in precipitation versus annual δ18O in precipitation (after Jouzel et al., 1987a). A large variety of isotope paleodata is available. Isotope signatures are measured directly in ice cores, groundwaters, and fluid inclusions in speleothems, and indirectly in precipitated calcite, tree ring cellulose, and other organic materials, particularly those in lake sediments. Polar ice cores are particularly suited for paleoclimate reconstructions. First, δp and Ts are strongly correlated in these regions, as illustrated in Figure 3 for Greenland and Antarctica. Second, they give direct access to the precipitation with little postdepositional change at least when the signal can be averaged over a certain number of years. Third, they provide continuous and potentially very detailed sequences with the longest record covering the last 420 ka (thousands of years) at the Vostok site in Antarctica (and possibly even older periods in the recently drilled EPICA

  4. Studies of passive and active plasmonic core-shell nanoparticles and their applications

    NASA Astrophysics Data System (ADS)

    Campbell, Sawyer Duane

    Coated nanoparticles (CNP) are core-shell particles consisting of differing layers of epsilon positive (EP) and epsilon negative (ENG) materials. The juxtaposition of these EP and ENG materials can lead to the possibility of coupling incident plane waves to surface plasmon resonances (SPR) for particles even highly subwavelength in size. We introduce standard models of the permittivities of the noble metals used in these CNPs, and propose corrections to them based on experimental data when their sizes are extremely small. Mie theory is the solution to plane wave scattering by spheres and we extend the solution here to spheres consisting of an arbitrary number of layers. We discuss the resonance behaviors of passive CNPs with an emphasis on how the Coated nanoparticles (CNP) are core-shell particles consisting of differing layers of epsilon positive (EP) and epsilon negative (ENG) materials. The juxtaposition of these EP and ENG materials can lead to the possibility of coupling incident plane waves to surface plasmon resonances (SPR) for particles even highly subwavelength in size. We introduce standard models of the permittivities of the noble metals used in these CNPs, and propose corrections to them based on experimental data when their sizes are extremely small. Mie theory is the solution to plane wave scattering by spheres and we extend the solution here to spheres consisting of an arbitrary number of layers. We discuss the resonance behaviors of passive CNPs with an emphasis on how the resonance wavelength can be tuned by controlling the material properties and radii of the various layers in the configuration. It is demonstrated that these passive CNPs have scattering cross sections much larger than their geometrical size, but their resonance strengths are attenuated because of the inherent losses in the metals.To overcome this limitation, we show how the introduction of active material into the CNPs can not only overcome these losses, but can actually lead to

  5. An experimental study of counter-rotating cores in elliptical galaxies

    NASA Technical Reports Server (NTRS)

    Miller, R. H.; Roelofs, G. R.; Smith, B. F.

    1990-01-01

    Recent observational studies (Franx and Illingworth 1987; Jedrzejewski and Schechter 1988; Bender 1988; Illingworth and Franx 1989) have shown that some elliptical galaxies have a small region near the center that rotates in the opposite direction from the outer parts of the galaxy. Often the rotation in the central part is much faster than that in the outer part. A few other galaxies show a small region near the center that rotates in the same direction as the rest of the galaxy, but much faster. Either way, the part near the center that shows a strange pattern of rotation (the 'core') has been interpreted as a distinct dynamical subsystem. Very briefly, the observational data seem to be that anomalies show up in rotation curves near the centers of some elliptical galaxies and that galaxies with these strange rotational properties do not show a photometric signature: there are no noticeable bumps in the brightness profile and no unusual shapes of isophotal contours that would suggest an excess of matter concentrated near the center. No strong color variations have been reported. The puzzle is to learn what we can about elliptical galaxies in general, and about galaxies with strange central regions in particular, from these observational facts. The authors' approach is experimental. They make a guess about the form of the dynamically distinct subsystem, and then build a galaxy model to test experimental consequences such as the amount of matter required to produce observable effects and the length of time over which these effects would remain observable. They sidestep questions about how the galaxy might have gotten to be that way in the first place. That gives them more freedom to explore a variety of suggestions about what kind of dynamical system might give rise to the observed rotational patterns.

  6. Phylogenetic study of dengue-3 virus in Taiwan with sequence analysis of the core gene.

    PubMed

    Tung, Yi-Ching; Lin, Kuei-Hsiang; Chang, Ko; Ke, Liang-Yin; Ke, Guan-Ming; Lu, Po-Liang; Lin, Chun-Yu; Chen, Yen-Hsu; Chiang, Horn-Che

    2008-02-01

    Dengue virus serotype 3 (dengue-3) has been classified into five genotypes (I-V) by phylogenetic analysis based on different viral genes. To investigate the genetic variability and evolutionary character of the dengue-3 isolates in southern Taiwan from 2005 to 2006, we analyzed the 290 nucleotides of the core (C) gene of 12 dengue-3 isolates and compared them with the published C gene sequences of global dengue-3 strains available in GenBank, including four isolates from 1998 and one isolate from 1999, from Taiwan. The dengue-3 viruses from 2005 to 2006 were not from continuous spread of an epidemic strain or re-emergence of the 2005 strains in the 2-year period because there was a 5.4-6.2% difference in the 290 nucleotides of the C gene and different genotypes between the 2005 and 2006 strains. Most of the nucleotide changes, compared with a prototype dengue-3 virus, H87, occurred in the third codon position and were non-synonymous mutations occurring naturally in the C gene. In addition, there was no consistent difference in the 290 nucleotides of the C gene between eight dengue fever and two dengue hemorrhagic fever isolates from 2006. The phylogenetic analysis indicates that the isolates from the 1998, 1999 and 2006 Taiwan dengue-3 epidemics are phylogenetically related and belong to genotype III. It was noted that the 2005 Taiwan dengue-3 isolates belong to another genotype. This molecular epidemiology study of dengue-3 viruses in Taiwan helps to elucidate whether there is a continuation of outbreaks in consecutive years, re-emergence of endemic dengue virus, or introduction of strains from other countries.

  7. Comparative morphological study on the lingual papillae and their connective tissue cores in rabbits.

    PubMed

    Nonaka, Kouji; Zheng, Jin Hua; Kobayashi, Kan

    2008-08-01

    The morphological structure of the lingual papillae and their connective tissue cores (CTC) in a rabbit were studied using LM and SEM and were compared to that of other animal species. Externally, the filiform papillae distributed on the anterior surface of the dorsal tongue were short and conical with a round base and had a flat area on their anterior upper half. The CTC of the conical filiform papillae had a roughly triangular plate-like structure with a round top. Several small round protrusions were found on both inclined planes of the triangle. Spearhead-like filiform papillae were distributed on the anterior edge of the lingual prominence and branched filiform papillae were on the posteriorly wide area of the prominence. These papillae on the prominence had a slightly ramified CTC that differed from that of the CTC of the conical filiform papillae distributed on the anterior tongue. Dome-like fungiform papillae were distributed among the conical filiform papillae of the anterior tongue and had a CTC with a roundish structure that was almost but, not quite spherical in appearance with 1 to 10 small round concave indentations for taste buds on their upper surface. The foliate papillae had approximately 15 parallel ridges separated by grooves. These ridges contained a parallel thin plate-like CTC exhibited after removal of the epithelium. The vallate papilla was comprised of a spherical central papilla and had a circular wall with a flower-like CTC almost resembling a carnation. The stereostructure of the rabbit's filiform CTC are comparatively described as being morphologically in between those of rodents and those of the guinea pig and Japanese serow. Such evolution has probably occurred due to the species unique masticatory and gustatory needs and functions. PMID:18975613

  8. The USDA barley core collection: genetic diversity, population structure, and potential for genome-wide association studies.

    PubMed

    Muñoz-Amatriaín, María; Cuesta-Marcos, Alfonso; Endelman, Jeffrey B; Comadran, Jordi; Bonman, John M; Bockelman, Harold E; Chao, Shiaoman; Russell, Joanne; Waugh, Robbie; Hayes, Patrick M; Muehlbauer, Gary J

    2014-01-01

    New sources of genetic diversity must be incorporated into plant breeding programs if they are to continue increasing grain yield and quality, and tolerance to abiotic and biotic stresses. Germplasm collections provide a source of genetic and phenotypic diversity, but characterization of these resources is required to increase their utility for breeding programs. We used a barley SNP iSelect platform with 7,842 SNPs to genotype 2,417 barley accessions sampled from the USDA National Small Grains Collection of 33,176 accessions. Most of the accessions in this core collection are categorized as landraces or cultivars/breeding lines and were obtained from more than 100 countries. Both STRUCTURE and principal component analysis identified five major subpopulations within the core collection, mainly differentiated by geographical origin and spike row number (an inflorescence architecture trait). Different patterns of linkage disequilibrium (LD) were found across the barley genome and many regions of high LD contained traits involved in domestication and breeding selection. The genotype data were used to define 'mini-core' sets of accessions capturing the majority of the allelic diversity present in the core collection. These 'mini-core' sets can be used for evaluating traits that are difficult or expensive to score. Genome-wide association studies (GWAS) of 'hull cover', 'spike row number', and 'heading date' demonstrate the utility of the core collection for locating genetic factors determining important phenotypes. The GWAS results were referenced to a new barley consensus map containing 5,665 SNPs. Our results demonstrate that GWAS and high-density SNP genotyping are effective tools for plant breeders interested in accessing genetic diversity in large germplasm collections.

  9. Core-core and core-valence correlation

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1988-01-01

    The effect of (1s) core correlation on properties and energy separations was analyzed using full configuration-interaction (FCI) calculations. The Be 1 S - 1 P, the C 3 P - 5 S and CH+ 1 Sigma + or - 1 Pi separations, and CH+ spectroscopic constants, dipole moment and 1 Sigma + - 1 Pi transition dipole moment were studied. The results of the FCI calculations are compared to those obtained using approximate methods. In addition, the generation of atomic natural orbital (ANO) basis sets, as a method for contracting a primitive basis set for both valence and core correlation, is discussed. When both core-core and core-valence correlation are included in the calculation, no suitable truncated CI approach consistently reproduces the FCI, and contraction of the basis set is very difficult. If the (nearly constant) core-core correlation is eliminated, and only the core-valence correlation is included, CASSCF/MRCI approached reproduce the FCI results and basis set contraction is significantly easier.

  10. An XMM-Newton Study of the Core of the Antlia Cluster: Heating and Chemical Enrichment in a Galaxy Cluster without a Cool Core

    NASA Astrophysics Data System (ADS)

    Hawley, William; Machacek, M.; Kraft, R. P.

    2011-09-01

    A fundamental question for models of structure formation is how energy and heavy elements are distributed throughout the intra-cluster medium (ICM) as the cluster evolves hierarchically by sub-cluster mergers along filaments in the cosmic web. The dominant dynamical processes -- hydrodynamic and tidal stripping, supernovae and stellar winds, bulk gas motions induced by mergers, and matter entrainment uplifted by AGN driven jets and buoyant bubbles -- create distinct X-ray signatures in surface brightness images and temperature and abundance maps of the cluster gas. The relative efficiencies of these processes during the early stages of cluster evolution are not well understood. We use a 53 ks XMM-Newton exposure of the inner 12 arcminutes of the Antlia cluster, the nearest example of a galaxy cluster in an intermediate merger stage without a cool core, to study energy and metal transport throughout the cluster gas. We construct density, temperature, pressure, entropy and abundance maps to identify gas motions and heat flows, relate these motions to the metal abundance ratios and gradients, and test simple models for chemical enrichment and heating of the Antlia cluster ICM.

  11. The Hollow Core: Failure of the General Education Curriculum. A Fifty College Study

    ERIC Educational Resources Information Center

    Latzer, Barry

    2004-01-01

    This report provides empirical proof of a disturbing trend in higher education. Over the last several decades colleges and universities have substituted so-called "distribution requirements" for a solid core curriculum. Distribution requirements enable students freely to choose their general education courses, the courses outside their…

  12. Apps-olutely Perfect! Apps to Support Common Core in the History/Social Studies Classroom

    ERIC Educational Resources Information Center

    Waters, Stewart; Kenna, Joshua; Bruce, Darrian

    2016-01-01

    The inclusion of technology in the classroom is an increasingly important feature of effective instruction. The implementation of Common Core Standards in many states also requires teachers to consider new pedagogical strategies to support meaningful learning. This article explores the intersection between technology demands and curricular change…

  13. Common Core Implementation: Units of Study in Sacramento City. Practice Brief

    ERIC Educational Resources Information Center

    Knudson, Joel

    2014-01-01

    As district leaders search for the best ways to improve student learning with the Common Core State Standards, California districts are leading the way as early implementers of the new standards. The ideas and lessons emerging from their work can help other educators maximize the effectiveness of their own implementation efforts. This brief…

  14. The Study on the Core Concepts of Contemporary Sociology of Education and Its Theoretical Construction

    ERIC Educational Resources Information Center

    Qian, Min-hui

    2006-01-01

    Within the sphere of contemporary social sciences, the terms "modernity," "post-modernity" and "globalization" have penetrated, as the core concepts, into various fields of social sciences in a logical way. In constituting the concept of "modernity," sociology of education develops the educational theory, as sociological theory does, into a "grand…

  15. Synthetic Studies to Lyngbouilloside: A Phosphate Tether-Mediated Synthesis of the Macrolactone Core

    PubMed Central

    Chegondi, Rambabu

    2015-01-01

    A concise synthetic pathway to the originally assigned structure of lyngbouilloside macrolactone (3) is reported. The core macrocycle 3 was synthesized via a phosphate tether-mediated, one-pot, sequential RCM/CM/chemoselective hydrogenation reaction, Roskamp homologation, and a high yielding Boeckman acylketene cyclization. PMID:26388654

  16. A Case Study of the Army ROTC Core Curriculum and Its Implementation in the '70's.

    ERIC Educational Resources Information Center

    Miyasaki, Shuichi

    This essay examines the development of the Army ROTC core curriculum program and its implementation at the University of Hawaii, a school that has experienced anti-military sentiments. Data were principally obtained from search of laws, governmental regulations, publications and reports, newspapers, periodicals, and personal interviews. The…

  17. Study of Core Competency Elements and Factors Affecting Performance Efficiency of Government Teachers in Northeastern Thailand

    ERIC Educational Resources Information Center

    Chansirisira, Pacharawit

    2012-01-01

    The research aimed to investigate the core competency elements and the factors affecting the performance efficiency of the civil service teachers in the northeastern region, Thailand. The research procedure consisted of two steps. In the first step, the data were collected using a questionnaire with the reliability (Cronbach's Alpha) of 0.90. The…

  18. Preservice Teacher Preparation for Common Core Standards and Assessments: A Pilot Study

    ERIC Educational Resources Information Center

    Pae, Holly; Freeman, Greta G.; Wash, Pamela D.

    2014-01-01

    Teacher preparation programs face great challenges in ensuring their graduates are prepared for the demands of today's classrooms. The authors explore how teacher accountability has evolved based upon federal legislation leading to adoption of the Common Core State Standards (CCSS). Recognizing that future teachers will be held accountable…

  19. Core outcome measures for exercise studies in people with multiple sclerosis: recommendations from a multidisciplinary consensus meeting.

    PubMed

    Paul, Lorna; Coote, Susan; Crosbie, Jean; Dixon, Diane; Hale, Leigh; Holloway, Ed; McCrone, Paul; Miller, Linda; Saxton, John; Sincock, Caroline; White, Lesley

    2014-10-01

    Evidence shows that exercise is beneficial for people with multiple sclerosis (MS); however, statistical pooling of data is difficult because of the diversity of outcome measures used. The objective of this review is to report the recommendations of an International Consensus Meeting for a core set of outcome measures for use in exercise studies in MS. From the 100 categories of the International Classification of Function Core Sets for MS, 57 categories were considered as likely/potentially likely to be affected by exercise and were clustered into seven core groups. Outcome measures to address each group were evaluated regarding, for example, psychometric properties. The following are recommended: Modified Fatigue Impact Scale (MFIS) or Fatigue Severity Scale (FSS) for energy and drive, 6-Minute Walk Test (6MWT) for exercise tolerance, Timed Up and Go (TUG) for muscle function and moving around, Multiple Sclerosis Impact Scale (MSIS-29) or Multiple Sclerosis Quality of Life-54 Instrument (MSQoL54) for quality of life and body mass index (BMI) or waist-hip ratio (WHR) for the health risks associated with excess body fat. A cost effectiveness analysis and qualitative evaluation should be included where possible. Using these core measures ensures that future meta-analyses of exercise studies in MS are more robust and thus more effectively inform practice.

  20. Systematic Studies of Shock Revival and the Subsequent Evolutions in Core-collapse Supernovae with Parametric Progenitor Models

    NASA Astrophysics Data System (ADS)

    Yamamoto, Yu; Yamada, Shoichi

    2016-02-01

    We conducted one-dimensional and two-dimensional hydrodynamic simulations of post-shock revival evolutions in core-collapse supernovae, employing the simple neutrino light bulb approximation to produce explosions rather easily. In order to estimate the explosion energy, we took into proper account nuclear recombinations and fusions consistently with the equation of state for matter not in statistical equilibrium in general. The methodology is similar to our previous work, but is somehow improved. In this paper, we studied the influence of the progenitor structure on the dynamics systematically. In order to expedite our understanding of the systematics, we constructed six parametric progenitor models, which are different in masses of Fe iron core and Si+S layer, instead of employing realistic models provided by stellar evolution calculations, which are sometimes of stochastic nature as a function of stellar mass on the main sequence. We found that the explosion energy is tightly correlated with the mass accretion rate at shock revival irrespective of dimension and the progenitors with light iron cores but with rather high entropies, which have yet to be produced by realistic stellar evolution calculations, may reproduce the canonical values of explosion energy and nickel mass. The mass of the Si+S layer is also important in the mass accretion history after bounce, on the other hand; the higher mass accretion rates and resultant heavier cores tend to hamper strong explosions.

  1. [Nationwide questionnaire study in "the Model Core Curriculum" and current status for the undergraduate education in neurology].

    PubMed

    Sasaki, Hidenao; Arimura, Kimiyoshi; Itoyama, Yasuto; Kwak, Shin; Kira, Jun-Ichi; Nakashima, Kenji; Amano, Takahiro; Inoue, Kiyoharu; Uozumi, Takenori; Kohara, Nobuo; Tsuji, Sadatoshi; Tamagawa, Akira; Toyoshima, Itaru; Mizutani, Tomohiko; Yoshii, Fumihito; Sobue, Gen; Shimizu, Teruo

    2008-08-01

    To investigate the current state of education for undergraduates, the subcommittee of the Japanese Society of Neurology for undergraduate education sent a questionnaire on the 2001-version of Model Core Curriculum to the department of neurology in 80 medical universities and their 7 associate medical institutes throughout Japan. Answers were obtained from 56 out of those 87 institutes (64.4%). According to the answers, the Core Curriculum was introduced to the program of undergraduate education in 93% of those 56 universities. For the revision of neurology part in the current Core Curriculum, there are number of requests for improving the description on the neurological examination, list of common symptoms and disorders, and addition of therapeutics. Despite application of the Model Core Curriculum in medical education, the present study disclosed that there were considerable difference in the number and content of the lectures, and the duration of clinical clerkship in neurology ward. These differences of the curriculum and training program depends on not only the number of staffs, but also whether they are working as staffs in a department of neurology or as a small group of neurologists within a department other than neurology.

  2. Formation of metamorphic core complex in inherited wedges: A thermomechanical modelling study

    NASA Astrophysics Data System (ADS)

    Huet, B.; Le Pourhiet, L.; Labrousse, L.; Burov, E. B.; Jolivet, L.

    2011-09-01

    Metamorphic Core Complexes (MCCs) form when a thickened domain with a low-strength lower crust is submitted to extension. These structures are characteristic of post-orogenic extension, and field observations suggest that several MCCs rework a crustal nappe-stack emplaced before extension begins. These MCCs therefore develop within heterogeneous crusts that contain pre-existing dipping heterogeneities, such as thrust faults and dipping nappes in a crustal wedge. Although very common, this first order structural inheritance has never been considered in studies modelling MCCs. Our contribution therefore investigates the effect of an inherited crustal wedge structure on the dynamics and kinematics of formation of the MCCs, using fully coupled thermomechanical modelling. The wealth of petrological, structural and time informations available in the Cycladic MCCs (Aegean domain) allows setting up more realistic initial conditions for the experiments than usual flat-lying setups. It also allows the results of the numerical computation to be directly validated with final geometries, P-T paths and exhumation rates. The experiments using dipping heterogeneities are characterised by a much more complex evolution and final structure than their flat-lying layered equivalents. Dipping heterogeneities drive lateral strength contrasts and help to re-localise the deformation on successive detachments. The dip of the inherited wedge structures imposes kinematic constraints on the flow, which provides a model that explains the regional scale asymmetry of the Cycladic MCCs. The P-T paths, the exhumation rates and the final crustal structure that come out of an initial shallow-dipping wedge model provide a much more realistic comparison with their natural counter-parts than common flat-lying models. Other parameters, like crustal-scale density inversion, thermal structure and creep law parameters are of second order when compared to the initial wedge structure. Being little dependent

  3. A high-resolution study of complex organic molecules in hot cores

    NASA Astrophysics Data System (ADS)

    Calcutt, Hannah; Viti, Serena; Codella, Claudio; Beltrán, Maria T.; Fontani, Francesco; Woods, Paul M.

    2014-10-01

    We present the results of a line identification analysis using data from the IRAM Plateau de Bure Plateau de Bure Interferometer, focusing on six massive star-forming hot cores: G31.41+0.31, G29.96-0.02, G19.61-0.23, G10.62-0.38, G24.78+0.08A1 and G24.78+0.08A2. We identify several transitions of vibrationally excited methyl formate (HCOOCH3) for the first time in these objects as well as transitions of other complex molecules, including ethyl cyanide (C2H5CN), and isocyanic acid (HNCO). We also postulate a detection of one transition of glycolaldehyde (CH2(OH)CHO) in two new hot cores. We find G29.96-0.02, G19.61-0.23, G24.78+0.08A1 and G24.78+0.08A2 to be chemically very similar. G31.41+0.31, however, is chemically different: it manifests a larger chemical inventory and has significantly larger column densities. We suggest that it may represent a different evolutionary stage to the other hot cores in the sample, or it may surround a star with a higher mass. We derive column densities for methyl formate in G31.41+0.31, using the rotation diagram method, of 4 × 1017 cm-2 and a Trot of ˜170 K. For G29.96-0.02, G24.78+0.08A1 and G24.78+0.08A2, glycolaldehyde, methyl formate and methyl cyanide, all seem to trace the same material and peak at roughly the same position towards the dust emission peak. For G31.41+0.31, however, glycolaldehyde shows a different distribution to methyl formate and methyl cyanide and seems to trace the densest, most compact inner part of hot cores.

  4. Study on sensing characteristics of three-core photonic crystal fibers

    NASA Astrophysics Data System (ADS)

    Chen, Yue-e.; Shao, Qiu-feng; Wang, Yong

    2014-12-01

    Total-internal-reflection (TIR) typed fiber sensors based on photonic crystal fibers (PCFs) are made by filling samples into PCF cladding holes, where the interaction of light wave occurs between the evanescent wave of fiber core and the filled samples. This can avoid common transmission losses caused by fiber surface roughness. The interaction region of the evanescent wave in a PCF and the filled samples are almost coincident, so increasing fiber length can enhance the light-matter interaction and enable accurate detection of tiny changes of samples. However, it is difficult to inject sample materials into stomatal cladding of TIR-typed PCF sensors due to small volume of pores. In addition, the energy utilization rates of TIR-typed sensors are relatively low, only about 6%. A main influencing factor on the sensitivity of TIR-typed PCF sensors is the power fraction of pores in the whole cross section. In order to improve the sensitivity, one can elevate the power fraction of PCF pores. Based on the above considerations, a novel three-core double-clad PCF is designed, where samples are injected into the middle hole and two Yd-doped cores are arranged on its two sides for active excitation. Our theoretical calculation and experimental test show that this kind of structure can not only increase the coupling efficiency of the evanescent wave into the air holes effectively, but also gain higher detection sensitivity of trace samples.

  5. Studies of Deteriorated Heat Transfer in Prismatic Cores Stemming from Irradiation-Induced Geometry Distortion

    SciTech Connect

    Williams, Brian G.; Schultz, Richard R.; McEligot, Don M.; McCreery, Glenn

    2015-08-31

    A reference design for the Next Generation Nuclear Plant (NGNP) is to use General Atomics Modular High Temperature Gas-cooled Reactor (MHTGR). For such a configuration in normal operation, the helium coolant flow proceeds from the upper plenum to the lower plenum principally through the core coolant channels and the interstitial gaps (bypass flow) that separate the prismatic blocks from one another. Only the core prismatic blocks have coolant channels. The interstitial gaps are present throughout the core, the inner reflector region, and the out reflector region. The bypass flows in a prismatic gas-cooled reactor (GCR) are of potential concern because they reduce the desired flow rates in the coolant channels and, thereby, can increase outlet gas temperatures and maximum fuel temperatures. Consequently, it is appropriate to account for bypass flows in reactor thermal gas dynamic analyses. The objectives of this project include the following: fundamentally understand bypass flow and heat transfer at scaled, undistorted conditions and with geometry distortions; develop improved estimates of associated loss coefficients, surface friction and heat transfer for systems and network codes; and obtain related data for validation of CFD (computational fluid dynamic) or system (e.g., RELAP5) codes which can be employed in predictions for a GCR for normal power, reduced power, and residual heat removal operations.

  6. Genome-wide annotation, expression profiling, and protein interaction studies of the core cell-cycle genes in Phalaenopsis aphrodite.

    PubMed

    Lin, Hsiang-Yin; Chen, Jhun-Chen; Wei, Miao-Ju; Lien, Yi-Chen; Li, Huang-Hsien; Ko, Swee-Suak; Liu, Zin-Huang; Fang, Su-Chiung

    2014-01-01

    Orchidaceae is one of the most abundant and diverse families in the plant kingdom and its unique developmental patterns have drawn the attention of many evolutionary biologists. Particular areas of interest have included the co-evolution of pollinators and distinct floral structures, and symbiotic relationships with mycorrhizal flora. However, comprehensive studies to decipher the molecular basis of growth and development in orchids remain scarce. Cell proliferation governed by cell-cycle regulation is fundamental to growth and development of the plant body. We took advantage of recently released transcriptome information to systematically isolate and annotate the core cell-cycle regulators in the moth orchid Phalaenopsis aphrodite. Our data verified that Phalaenopsis cyclin-dependent kinase A (CDKA) is an evolutionarily conserved CDK. Expression profiling studies suggested that core cell-cycle genes functioning during the G1/S, S, and G2/M stages were preferentially enriched in the meristematic tissues that have high proliferation activity. In addition, subcellular localization and pairwise interaction analyses of various combinations of CDKs and cyclins, and of E2 promoter-binding factors and dimerization partners confirmed interactions of the functional units. Furthermore, our data showed that expression of the core cell-cycle genes was coordinately regulated during pollination-induced reproductive development. The data obtained establish a fundamental framework for study of the cell-cycle machinery in Phalaenopsis orchids.

  7. A MULTI-WAVELENGTH STUDY OF THE STAR-FORMING CORE AHEAD OF HH 80N

    SciTech Connect

    Masque, Josep M.; Estalella, Robert; Osorio, Mayra; Anglada, Guillem; Garay, Guido; Calvet, Nuria; Beltran, Maria T.

    2011-09-01

    We present observations of continuum emission in the mid-infrared to millimeter wavelength range, complemented with ammonia observations, of the dense core ahead of the radio Herbig-Haro (HH) object HH 80N, found in the GGD 27 region. The continuum emission in all the observed bands peaks at the same position, consistent with the presence of an embedded object, HH 80N-IRS1, within the core. The distribution of the Very Large Array ammonia emission is well correlated with that of the dust, suggesting that photochemical effects caused by the nearby HH object do not play an important role in shaping this particular molecular emission. In order to unveil the nature of HH 80N-IRS1, we analyzed the continuum data of this source, using self-consistent models of protostellar collapse. We find that a young protostar surrounded by a slowly rotating collapsing envelope of radius {approx}0.08 pc and 20 M{sub sun} plus a circumstellar disk of radius {approx}300 AU and 0.6 M{sub sun} provide a good fit to the observed spectral energy distribution and to the maps at 350 {mu}m, 1.2 mm, and 3.5 mm of HH 80N-IRS1. Besides, the Atacama Pathfinder Experiment and Plateau de Bure Interferometer continuum maps at 350 {mu}m and 3.5 mm, respectively, reveal additional clumps in the continuum emission. Given the modeling results and the observed morphology of the emission, we propose a scenario consisting of a central embedded Class 0 object, HH 80N-IRS1, with the rest of the material of the HH 80N core possibly undergoing fragmentation that may lead to the formation of several protostars.

  8. Spectroscopic study of temperature and density spatial profiles and mix in implosion cores

    SciTech Connect

    Welser-Sherrill, L.; Mancini, R. C.; Koch, J. A.; Izumi, N.; Tommasini, R.; Haan, S. W.; Haynes, D. A.; Golovkin, I. E.; MacFarlane, J. J.; Delettrez, J. A.; Marshall, F. J.; Regan, S. P.; Smalyuk, V. A.

    2008-10-22

    New techniques of x-ray spectroscopy have been developed to extract the temperature and density spatial structure of implosion cores. Results from an emissivity analysis, which neglects optical depth effects, compare well with the independent results of an intensity analysis used in the low optical depth limit. The intensity analysis has also been applied in its full form, in which case density spatial profiles demonstrate significant opacity effects. The emissivity and intensity analyses were combined to infer the spatial profile of mixing between shell and fuel material. This experimentally-derived information on mix is compared with predictions from two standard theoretical mix models.

  9. A comparative photophysicochemical study of phthalocyanines encapsulated in core-shell silica nanoparticles.

    PubMed

    Fashina, Adedayo; Amuhaya, Edith; Nyokong, Tebello

    2015-02-25

    This work presents the synthesis and characterization of a new zinc phthalocyanine complex tetrasubstituted with 3-carboxyphenoxy in the peripheral position. The photophysical properties of the new complex are compared with those of phthalocyanines tetra substituted with 3-carboxyphenoxy or 4-carboxyphenoxy at non-peripheral positions. Three phthalocyanine complexes were encapsulated within silica matrix to form a core shell and the hybrid nanoparticles particles obtained were spherical and mono dispersed. When encapsulated within the silica shell nanoparticles, phthalocyanines showed improved triplet quantum yields and singlet oxygen quantum yields than surface grafted derivatives. The improvements observed could be attributed to the protection provided for the phthalocyanine complexes by the silica matrix.

  10. Doping GaP Core-Shell Nanowire pn-Junctions: A Study by Off-Axis Electron Holography.

    PubMed

    Yazdi, Sadegh; Berg, Alexander; Borgström, Magnus T; Kasama, Takeshi; Beleggia, Marco; Samuelson, Lars; Wagner, Jakob B

    2015-06-10

    The doping process in GaP core-shell nanowire pn-junctions using different precursors is evaluated by mapping the nanowires' electrostatic potential distribution by means of off-axis electron holography. Three precursors, triethyltin (TESn), ditertiarybutylselenide, and silane are investigated for n-type doping of nanowire shells; among them, TESn is shown to be the most efficient precursor. Off-axis electron holography reveals higher electrostatic potentials in the regions of nanowire cores grown by the vapor-liquid-solid (VLS) mechanism (axial growth) than the regions grown parasitically by the vapor-solid (VS) mechanism (radial growth), attributed to different incorporation efficiency between VLS and VS of unintentional p-type carbon doping originating from the trimethylgallium precursor. This study shows that off-axis electron holography of doped nanowires is unique in terms of the ability to map the electrostatic potential and thereby the active dopant distribution with high spatial resolution.

  11. Design study of an air pump and integral lift engine ALF-504 using the Lycoming 502 core

    NASA Technical Reports Server (NTRS)

    Rauch, D.

    1972-01-01

    Design studies were conducted for an integral lift fan engine utilizing the Lycoming 502 fan core with the final MQT power turbine. The fan is designed for a 12.5 bypass ratio and 1.25:1 pressure ratio, and provides supercharging for the core. Maximum sea level static thrust is 8370 pounds with a specific fuel consumption of 0.302 lb/hr-lb. The dry engine weight without starter is 1419 pounds including full-length duct and sound-attenuating rings. The engine envelope including duct treatment but not localized accessory protrusion is 53.25 inches in diameter and 59.2 inches long from exhaust nozzle exit to fan inlet flange. Detailed analyses include fan aerodynamics, fan and reduction gear mechanical design, fan dynamic analysis, engine noise analysis, engine performance, and weight analysis.

  12. Exact versus Taylor-expanded energy density in the study of the neutron star crust-core transition

    NASA Astrophysics Data System (ADS)

    Routray, T. R.; Viñas, X.; Basu, D. N.; Pattnaik, S. P.; Centelles, M.; Robledo, L. B.; Behera, B.

    2016-10-01

    The importance of the fourth and higher order terms in the Taylor series expansion of energy of isospin asymmetric nuclear matter in studies of the neutron star crust-core phase transition is investigated using the finite-range simple effective interaction. Analytic expressions for the evaluation of the second and fourth order derivative terms in the Taylor series expansion for any general finite-range interaction of Yukawa, exponential or Gaussian form have been obtained. The effect of the nuclear matter incompressibility, symmetry energy and slope parameters on the predictions for the crust-core transition density is examined. The crustal moment of inertia is calculated and the prediction for the radius of the Vela pulsar is analyzed using different equations of state.

  13. A study on fast reactor core mechanics by an ex-reactor test and comparisons with calculations

    SciTech Connect

    Tottori, Shoji; Kawanaka, Ikunori; Nakagawa, Masatoshi; Arie, Kazuo; Itoh, Kunihiro; Ohya, Takeaki; Motomiya, Takeo; Adachi, Hironori

    1996-07-01

    This paper presents and discusses the results of core bowing experiments performed with an ex-reactor rig holding a half hexagon array of 22 sub-assemblies (S/As) simulating the Japanese DFBR conditions and the comparisons of the measured results with calculations by individually developed codes--ARKAS, RAINBOW, SANBOW. The main conclusions of this study are (1) interwrapper loads and S/A displacements within the array were measured at selected positions for a series of five tests simulating the DFBR core bowing modes, (2) the overall comparison between the non-friction calculation and measurement showed good agreement for loads, displacements and their directions, and (3) validation of the friction algorithm has also been carried out and further improvement of the agreement was obtained.

  14. Direct laser-driven ramp compression studies of iron: A first step toward the reproduction of planetary core conditions

    NASA Astrophysics Data System (ADS)

    Amadou, N.; Brambrink, E.; Benuzzi-Mounaix, A.; Huser, G.; Guyot, F.; Mazevet, S.; Morard, G.; de Resseguier, T.; Vinci, T.; Myanishi, K.; Ozaki, N.; Kodama, R.; Boehly, T.; Henry, O.; Raffestin, D.; Koenig, M.

    2013-06-01

    The study of iron under quasi-isentropic compression using high energy lasers, might allow to understand its thermodynamical properties, in particular its melting line in conditions of pressure and temperature relevant to Earth-like planetary cores (330-1500 GPa, 5000-8000 K). However, the iron alpha-epsilon solid-solid phase transition at 13 GPa favors shock formation during the quasi-isentropic compression process which can depart from the appropriate thermodynamical path. Understanding this shock formation mechanism is a key issue for being able to reproduce Earth-like planetary core conditions in the laboratory by ramp compression. In this article, we will present recent results of direct laser-driven quasi-isentropic compression experiments on iron samples obtained on the LULI 2000 and LIL laser facilities.

  15. [Study of biological molecules in water by using the resonance raman spectra in liquid-core optical fiber].

    PubMed

    Jia, Li-Hua; Wang, Yi-Ding; Sun, Cheng-Lin; Li, Zhan-Long; Li, Zuo-Wei; Wang, Li-Jun

    2009-10-01

    Raman spectrum is an important and effective method for the study of biological molecules in water. Measuring the Raman spectra for biological molecules in water, however, is very difficult because of the small Raman scattering cross section and the high electronic excitation energy of water molecules. In the present paper, the authors applied both technologies of liquid-core optical fiber and the resonance Raman spectra, then the intensity of Raman spectra was enhanced to a great extent. In this experiment, we chose the laser wavelength 514.5 of Ar+ ion laser as excitation laser, because we could obtain the maximal intensity of resonance Raman spectra at this wavelength. The experiment results show that, for the trace inspecting study of beta-carotene biological molecules in water, the concentration in the range of 10(-7)-10(-9) mol x L(-1) can be detected by quartz liquid-core optical fiber and the concentration in the range of 10(-9)-10(-10) mol x L(-1) by Teflon liquid-core optical fiber. The detecting utmost will be further reduced if improving the quality of optical fiber. PMID:20038038

  16. Structure and Dimensions of Core-Shell Nanoparticles Comparable to the Confocal Volume Studied by Means of Fluorescence Correlation Spectroscopy.

    PubMed

    Gapinski, Jacek; Jarzębski, Maciej; Buitenhuis, Johan; Deptula, Tobiasz; Mazuryk, Jaroslaw; Patkowski, Adam

    2016-03-15

    In some applications the dye distribution within fluorescently labeled nanoparticles and its stability over long periods of time are important issues. In this article we study numerically and experimentally the applicability of fluorescence correlation spectroscopy (FCS) to resolve such questions. When the size of fluorescently labeled particles is comparable to or larger than the confocal volume, the effective confocal volume seen in FCS experiments is increasing. Such an effect has already been studied for uniformly labeled spherical particles. In this work we analyze the form of the FCS correlation functions (CFs) for core-labeled and shell-labeled core-shell particles. For shell-labeled particles an additional fast decay was found both in simulations and in experiments on custom-made surface-labeled particles. Universal scaling of FCS correlation times based on the squared ratio of the labeled part radius of gyration to the Gaussian radius of the beam profile was found. Recipes based on the analysis of simulated CFs, proposed for interpretation of experimental results, were successfully applied to the FCS results on suspensions of large core-labeled and surface-labeled particles.

  17. Contributions from geomagnetic inverse theory to the study of hydromagnetic conditions near the core-mantle boundary

    NASA Technical Reports Server (NTRS)

    Backus, George E.

    1991-01-01

    The Final Report on contributions from geomagnetic inverse theory to the study of hydromagnetic conditions near the core-mantle boundary (CMB) is presented. The original proposal was to study five questions concerning what the surface and satellite magnetic data imply about hydromagnetic and electromagnetic conditions near the CMB. The five questions are: (1) what do the surface and satellite data imply about the geomagnetic field B near the surface of the earth; (2) how does one extrapolate B down through the conducting mantle to the CMB; (3) if B on the CMB is visible, how accurately does it satisfy the frozen-flux approximation; (4) if frozen flux is a good approximation on the CMB, what can be inferred about the fluid velocity v in the upper core; and (5) if v at the CMB is visible, does it suggest any dynamical properties of the core, such as vertical advection, Alfven-inertial waves, link instabilities, or mantle effects. A summary of the research is provided.

  18. Theoretical and Experimental Studies of Epidermal Heat Flux Sensors for Measurements of Core Body Temperature.

    PubMed

    Zhang, Yihui; Webb, Richard Chad; Luo, Hongying; Xue, Yeguang; Kurniawan, Jonas; Cho, Nam Heon; Krishnan, Siddharth; Li, Yuhang; Huang, Yonggang; Rogers, John A

    2016-01-01

    Long-term, continuous measurement of core body temperature is of high interest, due to the widespread use of this parameter as a key biomedical signal for clinical judgment and patient management. Traditional approaches rely on devices or instruments in rigid and planar forms, not readily amenable to intimate or conformable integration with soft, curvilinear, time-dynamic, surfaces of the skin. Here, materials and mechanics designs for differential temperature sensors are presented which can attach softly and reversibly onto the skin surface, and also sustain high levels of deformation (e.g., bending, twisting, and stretching). A theoretical approach, together with a modeling algorithm, yields core body temperature from multiple differential measurements from temperature sensors separated by different effective distances from the skin. The sensitivity, accuracy, and response time are analyzed by finite element analyses (FEA) to provide guidelines for relationships between sensor design and performance. Four sets of experiments on multiple devices with different dimensions and under different convection conditions illustrate the key features of the technology and the analysis approach. Finally, results indicate that thermally insulating materials with cellular structures offer advantages in reducing the response time and increasing the accuracy, while improving the mechanics and breathability.

  19. Cytotoxicity and biodistribution studies on PEGylated EDA and PEG cored PAMAM dendrimers.

    PubMed

    Gürbüz, Mustafa U; Öztürk, Kıvılcım; Ertürk, Ali S; Yoyen-Ermis, Digdem; Esendagli, Gunes; Çalış, Sema; Tülü, Metin

    2016-11-01

    Starting from Ethylenediamine (EDA) or poly(ethylene glycol) tetra amine (4-arm-PEG) cores, two different peripheral methylester (-COOCH3) or amine (-NH2) PAMAM dendrimers have been synthesized. In the growth phase of dendrimers, two important building blocks, methyl acrylate for the half generation and EDA for the full generations, have been used. In order to improve the yield and decrease the time for the aminolysis step, a microwave-assisted technique was applied. Both of these dendrimers with different cores were grown up to 4.5 generations where surface modification, i.e. PEGylation, with 10% Poly(ethylene glycol) bis(amine) was performed. In order to increase the solubility of dendrimers, esteric surfaces were converted to carboxylic acid groups. Accordingly, the dendrimers were soluble in water or in water-methanol mixture which enabled their purification by liquid-phase polymer-based retention in each step. Finally, the resulting products that were characterized with (NMR and FTIR) spectroscopy were evaluated in vitro and in vivo. The analytical grade dendrimers were not cytotoxic to mouse fibroblasts and their biodistribution was mainly determined in the site of injection (peritoneum), liver and kidneys.

  20. Cytotoxicity and biodistribution studies on PEGylated EDA and PEG cored PAMAM dendrimers.

    PubMed

    Gürbüz, Mustafa U; Öztürk, Kıvılcım; Ertürk, Ali S; Yoyen-Ermis, Digdem; Esendagli, Gunes; Çalış, Sema; Tülü, Metin

    2016-11-01

    Starting from Ethylenediamine (EDA) or poly(ethylene glycol) tetra amine (4-arm-PEG) cores, two different peripheral methylester (-COOCH3) or amine (-NH2) PAMAM dendrimers have been synthesized. In the growth phase of dendrimers, two important building blocks, methyl acrylate for the half generation and EDA for the full generations, have been used. In order to improve the yield and decrease the time for the aminolysis step, a microwave-assisted technique was applied. Both of these dendrimers with different cores were grown up to 4.5 generations where surface modification, i.e. PEGylation, with 10% Poly(ethylene glycol) bis(amine) was performed. In order to increase the solubility of dendrimers, esteric surfaces were converted to carboxylic acid groups. Accordingly, the dendrimers were soluble in water or in water-methanol mixture which enabled their purification by liquid-phase polymer-based retention in each step. Finally, the resulting products that were characterized with (NMR and FTIR) spectroscopy were evaluated in vitro and in vivo. The analytical grade dendrimers were not cytotoxic to mouse fibroblasts and their biodistribution was mainly determined in the site of injection (peritoneum), liver and kidneys. PMID:27534577

  1. A Centrifuge-Based Technique for Dry Extraction of Air for Ice Core Studies of Carbon Dioxide.

    NASA Astrophysics Data System (ADS)

    Grachev, A. M.; Brook, E. J.

    2008-12-01

    High resolution CO2 data from the Law Dome ice core document an abrupt ~10 ppm drop in CO2 at about 1600 AD (MacFarling Meure et al., Geophys. Res Lett., v. 33, L14810), which has been attributed to changes in human activities. CO2 measurements in ice cores are difficult, however, making verification of this feature an important task. We are undertaking a high-resolution study of CO2 between 1400 and 1800 AD in the WAIS Divide (Antarctica) ice core with a new dry extraction technique. The need for a dry extraction technique as opposed to a melt-refreeze technique in studies of CO2 from ice cores arises because of the well-documented artifacts in CO2 imposed by the presence of liquid water. Three dry-extraction methods have been employed by previous workers to measure CO2: needle-crushing method, ball-bearings method, and cheese-grater method (B. Stauffer, in: Encyclopedia of Quaternary Science, p. 1181, Elsevier 2007). Each has limitations, and we propose a simpler dry extraction technique, based on a large-capacity refrigerated centrifuge (the "centrifuge technique"), which eliminates the need to employ cryogenic temperatures to collect extracted gas and is more compatible with high sample throughput. The technique is now being tested on ~25-gram WAIS Divide samples in conjunction with CO2 measurements with a gas chromatograph. The technique employs a Beckman J- 6B centrifuge, in which evacuated stainless steel flask is placed: the flask has a weight inside positioned directly over a tall-standing piece of ice whose cross-section is small compared to that of the flask. Upon acceleration to 3000 rpm the weight moves down and presses the ice sample into a thin tablet covering flask's bottom, yielding the air extraction efficiency of ~80%. Preliminary tests suggest that precision and accuracy can be achieved at the level of ~1 ppm once the system is fine-tuned.

  2. Structural Studies of Lipopolysaccharide-defective Mutants from Brucella melitensis Identify a Core Oligosaccharide Critical in Virulence*

    PubMed Central

    Fontana, Carolina; Conde-Álvarez, Raquel; Ståhle, Jonas; Holst, Otto; Iriarte, Maite; Zhao, Yun; Arce-Gorvel, Vilma; Hanniffy, Seán; Gorvel, Jean-Pierre; Moriyón, Ignacio; Widmalm, Göran

    2016-01-01

    The structures of the lipooligosaccharides from Brucella melitensis mutants affected in the WbkD and ManBcore proteins have been fully characterized using NMR spectroscopy. The results revealed that disruption of wbkD gives rise to a rough lipopolysaccharide (R-LPS) with a complete core structure (β-d-Glcp-(1→4)-α-Kdop-(2→4)[β-d-GlcpN-(1→6)-β-d-GlcpN-(1→4)[β-d-GlcpN-(1→6)]-β-d-GlcpN-(1→3)-α-d-Manp-(1→5)]-α-Kdop-(2→6)-β-d-GlcpN3N4P-(1→6)-α-d-GlcpN3N1P), in addition to components lacking one of the terminal β-d-GlcpN and/or the β-d-Glcp residues (48 and 17%, respectively). These structures were identical to those of the R-LPS from B. melitensis EP, a strain simultaneously expressing both smooth and R-LPS, also studied herein. In contrast, disruption of manBcore gives rise to a deep-rough pentasaccharide core (β-d-Glcp-(1→4)-α-Kdop-(2→4)-α-Kdop-(2→6)-β-d-GlcpN3N4P-(1→6)-α-d-GlcpN3N1P) as the major component (63%), as well as a minor tetrasaccharide component lacking the terminal β-d-Glcp residue (37%). These results are in agreement with the predicted functions of the WbkD (glycosyltransferase involved in the biosynthesis of the O-antigen) and ManBcore proteins (phosphomannomutase involved in the biosynthesis of a mannosyl precursor needed for the biosynthesis of the core and O-antigen). We also report that deletion of B. melitensis wadC removes the core oligosaccharide branch not linked to the O-antigen causing an increase in overall negative charge of the remaining LPS inner section. This is in agreement with the mannosyltransferase role predicted for WadC and the lack of GlcpN residues in the defective core oligosaccharide. Despite carrying the O-antigen essential in B. melitensis virulence, the core deficiency in the wadC mutant structure resulted in a more efficient detection by innate immunity and attenuation, proving the role of the β-d-GlcpN-(1→6)-β-d-GlcpN-(1→4)[β-d-GlcpN-(1→6)]-β-d-GlcpN-(1→3)-

  3. Exploring effective core drug patterns in primary insomnia treatment with Chinese herbal medicine: study protocol for a randomized controlled trial

    PubMed Central

    2013-01-01

    Background Chinese herbal medicine is one of the most popular Chinese medicine (CM) therapies for primary insomnia. One of the important characteristics of CM is that different Chinese clinicians give different prescriptions even for the same patient. However, there must be some fixed drug patterns in every clinician’s prescriptions. This study aims to screen the effective core drug patterns in primary insomnia treatment of three prestigious Chinese clinicians. Methods/design A triple-blind, randomized, placebo-controlled, parallel-group clinical trial will be performed. Three clinicians will diagnose and treat every eligible patient individually and independently, producing three prescriptions from three clinicians for every patient. Patients will equally be randomized to one of four groups – medical group A, medical group B, medical group C, or placebo group – and observed for efficacy of treatment. The sample will include primary insomnia patients meeting DSM IV-TR criteria, Spiegel scale score >18, and age 18 to 65 years. A sequential design is employed. Interim analysis will be conducted when between 80 and 160 patients complete the study. The interim study could be stopped and treated as final if a statistically significant difference between treatment and placebo groups can be obtained and core effective drug patterns can be determined. Otherwise, the study continues until the maximum sample size reaches 300. Treatment of the CM group is one of three Chinese clinicians’ prescriptions, who provide independently prescriptions based on their own CM theory and the patient’s disease condition. Assessment will be by sleep diary and Pittsburgh sleep quality index, and CM symptoms and signs will be measured. Primary outcome is total sleep time. Assessment will be carried out at the washout period, weeks 1, 2, 3, and 4 and 4th week after the end of treatment. Effectiveness analysis will be per intent to treat. A multi-dimension association rule and scale

  4. AN Core Analysis

    NASA Astrophysics Data System (ADS)

    Barbarino, Andrea; Tomatis, Daniele

    2014-06-01

    Several alternative approximations of neutron transport have been proposed in years to move around the known limitations imposed by neutron diffusion in the modeling of nuclear cores. However, only a few complied with the industrial requirements of fast numerical computation, concentrating more on physical accuracy. In this work, the AN transport methodology is discussed with particular interest in core performance calculations. The implementation of the methodology in full core codes is discussed with particular attention to numerical issues and to the integration within the entire simulation process. Finally, first results from core studies in AN transport are analyzed in detail and compared to standard results of neutron diffusion.

  5. Material combinations and parametric study of thermal and mechanical performance of pyramidal core sandwich panels used for hypersonic aircrafts

    NASA Astrophysics Data System (ADS)

    Zhang, Ruiping; Zhang, Xiaoqing; Lorenzini, Giulio; Xie, Gongnan

    2016-11-01

    A novel kind of lightweight integrated thermal protection system, named pyramidal core sandwich panel, is proposed to be a good safeguard for hypersonic aircrafts in the current study. Such system is considered as not only an insulation structure but also a load-bearing structure. In the context of design for hypersonic aircrafts, an efficient optimization should be paid enough attention. This paper concerns with the homogenization of the proposed pyramidal sandwich core panel using two-dimensional model in subsequent research for material selection. According to the required insulation performance and thermal-mechanical properties, several suitable material combinations are chosen as candidates for the pyramidal core sandwich panel by adopting finite element analysis and approximate response surface. To obtain lightweight structure with an excellent capability of heat insulation and load-bearing, an investigation on some specific design variables, which are significant for thermal-mechanical properties of the structure, is performed. Finally, a good balance between the insulation performance, the capability of load-bearing and the lightweight has attained.

  6. Impact of post-manipulation corrective core exercises on the spinal deformation and lumbar strength in golfers: a case study

    PubMed Central

    Shin, Chul-ho; Kim, Minjeong; Park, Gi Duck

    2015-01-01

    [Purpose] This study examined spinal shape in professional golfers with chronic back pain, and analyzed the effects of a 4-week regimen of semi-weekly manipulation and corrective core exercises on spinal shape. [Subjects] Two golfers with chronic back pain. [Methods] The pelvis and spinal vertebrae were corrected using the Thompson “drop” technique. Angle and force were adjusted to place the pelvis, lumbar spine, and thoracic vertebrae in neutral position. The technique was applied twice weekly after muscle massage in the back and pelvic areas. The golfers performed corrective, warmup stretching exercises, followed by squats on an unstable surface using the Togu ball. They then used a gym ball for repetitions of hip rotation, upper trunk extension, sit-ups, and pelvic anterior-posterior, pelvic left-right, and trunk flexion-extension exercises. The session ended with cycling as a cool-down exercise. Each session lasted 60 minutes. [Results] The difference in height was measured on the left and right sides of the pelvic bone. The pelvic tilt changed significantly in both participants after the 4-week program. [Conclusion] In golfers, core muscles are critical and are closely related to spinal deformation. Core strengthening and spinal correction play a pivotal role in the correction of spinal deformation. PMID:26504350

  7. Fabrication and Pilot In Vivo Study of a Collagen-BDDGE-Elastin Core-Shell Scaffold for Tendon Regeneration.

    PubMed

    Sandri, Monica; Filardo, Giuseppe; Kon, Elizaveta; Panseri, Silvia; Montesi, Monica; Iafisco, Michele; Savini, Elisa; Sprio, Simone; Cunha, Carla; Giavaresi, Gianluca; Veronesi, Francesca; Fini, Milena; Salvatore, Luca; Sannino, Alessandro; Marcacci, Maurilio; Tampieri, Anna

    2016-01-01

    The development of bio-devices for complete regeneration of ligament and tendon tissues is presently one of the biggest challenges in tissue engineering. Such device must simultaneously possess optimal mechanical performance, suitable porous structure, and biocompatible microenvironment. This study proposes a novel collagen-BDDGE-elastin (CBE)-based device for tendon tissue engineering, by the combination of two different modules: (i) a load-bearing, non-porous, "core scaffold" developed by braiding CBE membranes fabricated via an evaporative process and (ii) a hollow, highly porous, "shell scaffold" obtained by uniaxial freezing followed by freeze-drying of CBE suspension, designed to function as a physical guide and reservoir of cells to promote the regenerative process. Both core and shell materials demonstrated good cytocompatibility in vitro, and notably, the porous shell architecture directed cell alignment and population within the sample. Finally, a prototype of the core module was implanted in a rat tendon lesion model, and histological analysis demonstrated its safety, biocompatibility, and ability to induce tendon regeneration. Overall, our results indicate that such device may have the potential to support and induce in situ tendon regeneration. PMID:27446909

  8. Fabrication and Pilot In Vivo Study of a Collagen-BDDGE-Elastin Core-Shell Scaffold for Tendon Regeneration.

    PubMed

    Sandri, Monica; Filardo, Giuseppe; Kon, Elizaveta; Panseri, Silvia; Montesi, Monica; Iafisco, Michele; Savini, Elisa; Sprio, Simone; Cunha, Carla; Giavaresi, Gianluca; Veronesi, Francesca; Fini, Milena; Salvatore, Luca; Sannino, Alessandro; Marcacci, Maurilio; Tampieri, Anna

    2016-01-01

    The development of bio-devices for complete regeneration of ligament and tendon tissues is presently one of the biggest challenges in tissue engineering. Such device must simultaneously possess optimal mechanical performance, suitable porous structure, and biocompatible microenvironment. This study proposes a novel collagen-BDDGE-elastin (CBE)-based device for tendon tissue engineering, by the combination of two different modules: (i) a load-bearing, non-porous, "core scaffold" developed by braiding CBE membranes fabricated via an evaporative process and (ii) a hollow, highly porous, "shell scaffold" obtained by uniaxial freezing followed by freeze-drying of CBE suspension, designed to function as a physical guide and reservoir of cells to promote the regenerative process. Both core and shell materials demonstrated good cytocompatibility in vitro, and notably, the porous shell architecture directed cell alignment and population within the sample. Finally, a prototype of the core module was implanted in a rat tendon lesion model, and histological analysis demonstrated its safety, biocompatibility, and ability to induce tendon regeneration. Overall, our results indicate that such device may have the potential to support and induce in situ tendon regeneration.

  9. Fabrication and Pilot In Vivo Study of a Collagen-BDDGE-Elastin Core-Shell Scaffold for Tendon Regeneration

    PubMed Central

    Sandri, Monica; Filardo, Giuseppe; Kon, Elizaveta; Panseri, Silvia; Montesi, Monica; Iafisco, Michele; Savini, Elisa; Sprio, Simone; Cunha, Carla; Giavaresi, Gianluca; Veronesi, Francesca; Fini, Milena; Salvatore, Luca; Sannino, Alessandro; Marcacci, Maurilio; Tampieri, Anna

    2016-01-01

    The development of bio-devices for complete regeneration of ligament and tendon tissues is presently one of the biggest challenges in tissue engineering. Such device must simultaneously possess optimal mechanical performance, suitable porous structure, and biocompatible microenvironment. This study proposes a novel collagen-BDDGE-elastin (CBE)-based device for tendon tissue engineering, by the combination of two different modules: (i) a load-bearing, non-porous, “core scaffold” developed by braiding CBE membranes fabricated via an evaporative process and (ii) a hollow, highly porous, “shell scaffold” obtained by uniaxial freezing followed by freeze-drying of CBE suspension, designed to function as a physical guide and reservoir of cells to promote the regenerative process. Both core and shell materials demonstrated good cytocompatibility in vitro, and notably, the porous shell architecture directed cell alignment and population within the sample. Finally, a prototype of the core module was implanted in a rat tendon lesion model, and histological analysis demonstrated its safety, biocompatibility, and ability to induce tendon regeneration. Overall, our results indicate that such device may have the potential to support and induce in situ tendon regeneration. PMID:27446909

  10. Material combinations and parametric study of thermal and mechanical performance of pyramidal core sandwich panels used for hypersonic aircrafts

    NASA Astrophysics Data System (ADS)

    Zhang, Ruiping; Zhang, Xiaoqing; Lorenzini, Giulio; Xie, Gongnan

    2016-07-01

    A novel kind of lightweight integrated thermal protection system, named pyramidal core sandwich panel, is proposed to be a good safeguard for hypersonic aircrafts in the current study. Such system is considered as not only an insulation structure but also a load-bearing structure. In the context of design for hypersonic aircrafts, an efficient optimization should be paid enough attention. This paper concerns with the homogenization of the proposed pyramidal sandwich core panel using two-dimensional model in subsequent research for material selection. According to the required insulation performance and thermal-mechanical properties, several suitable material combinations are chosen as candidates for the pyramidal core sandwich panel by adopting finite element analysis and approximate response surface. To obtain lightweight structure with an excellent capability of heat insulation and load-bearing, an investigation on some specific design variables, which are significant for thermal-mechanical properties of the structure, is performed. Finally, a good balance between the insulation performance, the capability of load-bearing and the lightweight has attained.

  11. The USDA Barley Core Collection: Genetic Diversity, Population Structure, and Potential for Genome-Wide Association Studies

    PubMed Central

    Endelman, Jeffrey B.; Comadran, Jordi; Bonman, John M.; Bockelman, Harold E.; Chao, Shiaoman; Russell, Joanne; Waugh, Robbie; Hayes, Patrick M.; Muehlbauer, Gary J.

    2014-01-01

    New sources of genetic diversity must be incorporated into plant breeding programs if they are to continue increasing grain yield and quality, and tolerance to abiotic and biotic stresses. Germplasm collections provide a source of genetic and phenotypic diversity, but characterization of these resources is required to increase their utility for breeding programs. We used a barley SNP iSelect platform with 7,842 SNPs to genotype 2,417 barley accessions sampled from the USDA National Small Grains Collection of 33,176 accessions. Most of the accessions in this core collection are categorized as landraces or cultivars/breeding lines and were obtained from more than 100 countries. Both STRUCTURE and principal component analysis identified five major subpopulations within the core collection, mainly differentiated by geographical origin and spike row number (an inflorescence architecture trait). Different patterns of linkage disequilibrium (LD) were found across the barley genome and many regions of high LD contained traits involved in domestication and breeding selection. The genotype data were used to define ‘mini-core’ sets of accessions capturing the majority of the allelic diversity present in the core collection. These ‘mini-core’ sets can be used for evaluating traits that are difficult or expensive to score. Genome-wide association studies (GWAS) of ‘hull cover’, ‘spike row number’, and ‘heading date’ demonstrate the utility of the core collection for locating genetic factors determining important phenotypes. The GWAS results were referenced to a new barley consensus map containing 5,665 SNPs. Our results demonstrate that GWAS and high-density SNP genotyping are effective tools for plant breeders interested in accessing genetic diversity in large germplasm collections. PMID:24732668

  12. Study on the synthesis of the cyclopenta[f]indole core of raputindole A

    PubMed Central

    Marsch, Nils; Kock, Mario

    2016-01-01

    Summary The raputindoles from the rutaceous tree Raputia simulans share a cyclopenta[f]indole partial structure the synthesis of which is subject of this investigation. An efficient route to a series of 1,5-di(indol-6-yl)pentenones was developed via Mo/Au-catalyzed Meyer–Schuster rearrangement of tertiary propargylic alcohol precursors. However, none of the enones underwent the desired Nazarov cyclization to a cyclopenta[f]indole. More suitable were 6-hydroxyallylated indolines which gave good yields of cyclopenta[f]indolines after treatment with SnCl4, as soon as sterically demanding β-cyclocitral adducts were reacted. Most successful were Pt(II) and Au(I)-catalyzed cyclizations of N-TIPS-protected indolin-6-yl-substituted propargylacetates which provided the hydrogenated tricyclic cyclopenta[f]indole core system in high yield. PMID:26977193

  13. Core compressor exit stage study. Volume 1: Blading design. [turbofan engines

    NASA Technical Reports Server (NTRS)

    Wisler, D. C.

    1977-01-01

    A baseline compressor test stage was designed as well as a candidate rotor and two candidate stators that have the potential of reducing endwall losses relative to the baseline stage. These test stages are typical of those required in the rear stages of advanced, highly-loaded core compressors. The baseline Stage A is a low-speed model of Stage 7 of the 10 stage AMAC compressor. Candidate Rotor B uses a type of meanline in the tip region that unloads the leading edge and loads the trailing edge relative to the baseline Rotor A design. Candidate Stator B embodies twist gradients in the endwall region. Candidate Stator C embodies airfoil sections near the endwalls that have reduced trailing edge loading relative to Stator A. Tests will be conducted using four identical stages of blading so that the designs described will operate in a true multistage environment.

  14. Interstitial water studies on small core samples, Deep Sea Drilling Project: Leg 10

    USGS Publications Warehouse

    Manheim, Frank T.; Sayles, Fred L.; Waterman, Lee S.

    1973-01-01

    Leg 10 interstitial water analyses provide new indications of the distribution of rock salt beneath the floor of the Gulf of Mexico, both confirming areas previously indicated to be underlain by salt bodies and extending evidence of salt distribution to seismically featureless areas in the Sigsbee Knolls trend and Isthmian Embayment. The criterion for presence of salt at depth is a consistent increase in interstitial salinity and chlorinity with depth. Site 86, on the northern margin of the Yucatan Platform, provided no evidence of salt at depth. Thus, our data tend to rule out the suggestion of Antoine and Bryant (1969) that the Sigsbee Knolls salt was squeezed out from beneath the Yucatan Scarp. Cores from Sites 90 and 91, in the central Sigsbee Deep, were not obtained from a great enough depth to yield definite evidence for the presence of buried salt.

  15. Carbon combustion supernovae - Numerical studies of the final evolution of degenerate carbon-oxygen cores

    NASA Technical Reports Server (NTRS)

    Mueller, E.; Arnett, W. D.

    1986-01-01

    The evolution of polytropic 1.46-solar-mass 3-Gg/cu cm (4 x 10 to the 8th)-K pure C cores is investigated theoretically by means of model computations starting from the runaway stage. The temperature in central zones is raised to the runaway temperature, and the evolution is followed in a spherical coordinate system. In models of burning without detonation, it is found that the initially spherical burning front is Rayleigh-Taylor unstable, without bipolar jets or equatorial rings; that some C is not burned to Ni; and that the Ni in the 0.8-1.0 solar mass of burned fuel produced can account for observed properties of type I supernovae.

  16. Study on the synthesis of the cyclopenta[f]indole core of raputindole A.

    PubMed

    Marsch, Nils; Kock, Mario; Lindel, Thomas

    2016-01-01

    The raputindoles from the rutaceous tree Raputia simulans share a cyclopenta[f]indole partial structure the synthesis of which is subject of this investigation. An efficient route to a series of 1,5-di(indol-6-yl)pentenones was developed via Mo/Au-catalyzed Meyer-Schuster rearrangement of tertiary propargylic alcohol precursors. However, none of the enones underwent the desired Nazarov cyclization to a cyclopenta[f]indole. More suitable were 6-hydroxyallylated indolines which gave good yields of cyclopenta[f]indolines after treatment with SnCl4, as soon as sterically demanding β-cyclocitral adducts were reacted. Most successful were Pt(II) and Au(I)-catalyzed cyclizations of N-TIPS-protected indolin-6-yl-substituted propargylacetates which provided the hydrogenated tricyclic cyclopenta[f]indole core system in high yield. PMID:26977193

  17. Interstitial water studies on small core samples, Deep Sea Drilling Project, Leg 8

    USGS Publications Warehouse

    Manheim, F. T.; Sayles, F.L.

    1971-01-01

    Leg 8 sites are dominated by siliceous-calcareous biogenic oozes having depositional rates of 0.1 to 1.5 cm/1000 years. Conservative constituents of pore fluids showed, as have cores from other pelagic areas of the Pacific, insignificant or marginally significant changes with depth and location. However, in Sites 70 and 71, calcium, magnesium and strontium showed major shifts in concentration with depth. These changes appear to be related to recrystallization phenomena in skeletal debris of nannoplankton and to the relative accumulation rate of the sediments. The chemical anomalies increase relatively smoothly with depth, demonstrating the effectiveness of vertical diffusional communication, and apparent lack of bulk fluid movement, as noted in Leg 7 and other sites.

  18. Core design study of a supercritical light water reactor with double row fuel rods

    SciTech Connect

    Zhao, C.; Wu, H.; Cao, L.; Zheng, Y.; Yang, J.; Zhang, Y.

    2012-07-01

    An equilibrium core for supercritical light water reactor has been designed. A novel type of fuel assembly with dual rows of fuel rods between water rods is chosen and optimized to get more uniform assembly power distributions. Stainless steel is used for fuel rod cladding and structural material. Honeycomb structure filled with thermal isolation is introduced to reduce the usage of stainless steel and to keep moderator temperature below the pseudo critical temperature. Water flow scheme with ascending coolant flow in inner regions is carried out to achieve high outlet temperature. In order to enhance coolant outlet temperature, the radial power distributions needs to be as flat as possible through operation cycle. Fuel loading pattern and control rod pattern are optimized to flatten power distribution at inner regions. Axial fuel enrichment is divided into three parts to control axial power peak, which affects maximum cladding surface temperature. (authors)

  19. Molecular simulation study of polar order in orthogonal bent-core smectic liquid crystals.

    PubMed

    Peroukidis, Stavros D; Vanakaras, Alexandros G; Photinos, Demetri J

    2015-06-01

    We explore the phase behavior and structure of orthogonal smectic liquid crystals consisting of bent-core molecules (BCMs) by means of Monte Carlo molecular simulations. A simple athermal molecular model is introduced that describes the basic features of the BCMs. Phase transitions between uniaxial and biaxial (antiferroelectric) orthogonal smectics are obtained. The results indicate the presence of local in-plane polar correlations in the uniaxial smectic phase. The macroscopic uniaxial-biaxial transformation is rationalized in terms of local polar correlations giving rise to polar domains. The size of these polar domains grows larger under the action of an external vector field and their internal ordering is enhanced, leading to field-induced biaxial order-disorder transitions.

  20. Metal isotope and density functional study of the tetracarboxylatodicopper(II) core vibrations.

    PubMed

    Drozdzewski, Piotr; Brozyna, Anna

    2005-11-01

    Vibrational spectra of tetrakis(acetato)diaquadicopper(II) complex have been deeply examined in order to provide a detailed description of dynamics of [Cu(2)O(8)C(4)] core being a typical structural unit of most copper(II) carboxylates. Low frequency bands related to significant motions of metal atoms were detected by metal isotope substitution. Observed spectra and isotope shifts were reproduced in DFT calculations. For clear presentation of computed normal vibrations, a D(4h) symmetry approximation was successfully applied. Basing on observed isotope shifts and calculation results, all skeletal vibrations have been analyzed including normal mode with the largest Cu...Cu stretching amplitude assigned to Raman band at 178 cm(-1).

  1. Making an Ice Core.

    ERIC Educational Resources Information Center

    Kopaska-Merkel, David C.

    1995-01-01

    Explains an activity in which students construct a simulated ice core. Materials required include only a freezer, food coloring, a bottle, and water. This hands-on exercise demonstrates how a glacier is formed, how ice cores are studied, and the nature of precision and accuracy in measurement. Suitable for grades three through eight. (Author/PVD)

  2. Constraints on core formation from systematic study of metal-silicate partitioning on a great number of siderophile elements

    NASA Astrophysics Data System (ADS)

    Siebert, J.; Ryerson, F. J.

    2008-12-01

    The abundances of siderophile elements in the Earth's mantle are the result of core formation in the early Earth. Many variables are involved in the prediction of metal/silicate siderophile partition coefficients during core segregation: pressure, temperature, oxygen fugacity, silicate and metal compositions. Despite publications of numerous results of metal-silicate experiments, the experimental database and predictive expressions for elements partitioning are hampered by a lack of systematic study to separate and evaluate the effects of each variable. Only a relatively complete experimental database that describes Ni and Co partitioning now exists but is not sufficient to unambiguously decide between the most popular model for core formation with a single stage core-mantle equilibration at the bottom of a deep magma ocean (e.g. Li and Agee, 2001) and more recent alternative models (e.g. Wade and Wood, 2005; Rubie et al., 2007). In this experimental work, systematic study of metal silicate partitioning is presented for elements normally regarded as moderately siderophile (Mo, As, Ge, W, P, Ni, Co), slightly siderophile (Zn, Ga, Mn, V, Cr) and refractory lithophile (Nb, Ta). Using a new piston-cylinder design assembly allows us to present a suite of isobaric partitioning experiments at 3 GPa within a temperature range from 1600 to 2600° C and over a range of relative oxygen fugacity from IW-1.5 to IW-3.5. Silicate melts range from basaltic to peridotite in composition. The individual effect of pressure is also investigated through a combination of piston cylinder and multi anvil isothermal experiments from 0.5 to 18 GPa at 1900° C. Absolute measurements of partitioning coefficients combining EMP and LA-ICPMS analytical methods are provided. New results are obtained for elements whose partitioning behavior is usually poorly constrained and not integrated into any accretion or core formation models. We find notably that Ge, As, Mo become less siderophile with

  3. Constraints on core formation from systematic study of metal-silicate partitioning on a great number of siderophile elements

    SciTech Connect

    Siebert, J; Ryerson, F J

    2008-10-27

    The abundances of siderophile elements in the Earth's mantle are the result of core formation in the early Earth. Many variables are involved in the prediction of metal/silicate siderophile partition coefficients during core segregation: pressure, temperature, oxygen fugacity, silicate and metal compositions. Despite publications of numerous results of metal-silicate experiments, the experimental database and predictive expressions for elements partitioning are hampered by a lack of systematic study to separate and evaluate the effects of each variable. Only a relatively complete experimental database that describes Ni and Co partitioning now exists but is not sufficient to unambiguously decide between the most popular model for core formation with a single stage core-mantle equilibration at the bottom of a deep magma ocean (e.g. Li and Agee, 2001) and more recent alternative models (e.g. Wade and Wood, 2005; Rubie et al., 2007). In this experimental work, systematic study of metal silicate partitioning is presented for elements normally regarded as moderately siderophile (Mo, As, Ge, W, P, Ni, Co), slightly siderophile (Zn, Ga, Mn, V, Cr) and refractory lithophile (Nb, Ta). Using a new piston-cylinder design assembly allows us to present a suite of isobaric partitioning experiments at 3 GPa within a temperature range from 1600 to 2600 C and over a range of relative oxygen fugacity from IW-1.5 to IW-3.5. Silicate melts range from basaltic to peridotite in composition. The individual effect of pressure is also investigated through a combination of piston cylinder and multi anvil isothermal experiments from 0.5 to 18 GPa at 1900 C. Absolute measurements of partitioning coefficients combining EMP and LA-ICPMS analytical methods are provided. New results are obtained for elements whose partitioning behavior is usually poorly constrained and not integrated into any accretion or core formation models. We find notably that Ge, As, Mo become less siderophile with

  4. Preliminary Results from a Late Pleistocene to Holocene Paleoclimate Study of the Lake Sediment Cores, Northern New Mexico

    NASA Astrophysics Data System (ADS)

    Cedillo, D. N.; Brister, A. R.; LoPresti, C. A.; Maldonado, M.; Pitrucha, R. M.; West, C.; Martinez, E.; Lineline, J.; Petronis, M. S.

    2011-12-01

    We present the preliminary results from an integrated, paleoclimatic study of sediment cores collected from the Las Vegas National Wildlife Refuge (LVNWR) and surrounding region that bear on the late Pleistocene to Holocene paleoclimatic variations in northeastern NM. We collected sedimentologic, midge fossil, and rock magnetic data from sediment cores to characterize the materials, identify stratigraphic changes, document shifting lake levels, assess temperature changes, and infer paleoclimate conditions. Data from McAllister and Wallace Lake are encouraging and reveal depth dependent changes in fossil assemblages, grain size, and rock magnetic properties that we interpret to reflect climatic driven variations impacting the depositional system. We recognize three different types of chironomid subfamilies (Chironomini, Tanypodinae, and Orthocladiinae). Based on the fossil results, the water has been warm in the most recent years. Grain size distribution from the lower to upper core levels reveal that the amount of fine sand-sized sediment (0.125 mm diameter) increases while the amount of medium (0.25) to coarse (0.50) sand-sized sediment decreases implying that there may have been a reduction in stream energy and hence precipitation over the time period represented by the core. Bulk low-field magnetic susceptibility decreases by an order of magnitude from the surface to the base of the measured core suggesting a change in detrital magnetic influx into the lacustrian system. Curie point estimates indicate that the dominant magnetic mineral in all samples is cubic, low-Ti titanomagnetite phase. We postulate that concurrent with alpine glacial activity during the Pleistocene, the LVNWR and the transitional Great Plains region to the northeast was an expansive single lake or interconnected lake system, analogous to the Pleistocene lakes of the Estancia Basin (Lake Estancia) and the Tularosa Basin (Lake Otero) of central and southern NM. Following the end of glacial

  5. Gate field induced switching of electronic current in Si-Ge Core-Shell nanowire quantum dots: A first principles study

    NASA Astrophysics Data System (ADS)

    Dhungana, Kamal B.; Jaishi, Meghnath; Pati, Ranjit

    Core-shell nanowires are formed by varying the radial composition of the nanowires. One of the most widely studied core-shell nanowire groups in recent years is the Si-Ge and Ge-Si core-shell nanowires. Compared to their pristine counterparts, they are reported to have superior electronic properties. For example, the scaled ON state current value in a Ge-Si core-shell nanowire field effect transistor (FET) is reported to be three to four times higher than that observed in state-of-the-art-metal oxide semiconductor FET (MOSFET) (Nature, 441, 489 (2006)). Here, we study the transport properties of the pristine Si and Si-Ge core-shell nanowire quantum dots of similar dimension to understand the superior performance of Si-Ge core-shell nanowire field effect transistor. Our calculations yield excellent gate field induced switching behavior in current for both pristine Si and Si-Ge core-shell hetero-structure nanowire quantum dots. The threshold gate bias for ON/OFF switching in the Si-Ge core-shell nanowire is found to be much smaller than that found in the pristine Si nanowire. A single particle many-body Green's function approach in conjunction with density functional theory is employed to calculate the electronic current.

  6. Study of laser-induced damage to large core silica fiber by Nd:YAG and Alexandrite lasers

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoguang; Li, Jie; Hokansson, Adam; Whelan, Dan; Clancy, Michael

    2009-02-01

    As a continuation of our earlier study at 2.1 μm wavelength, we have investigated the laser damage to several types of step-index, large core (1500 μm) silica fibers at two new wavelengths by high power long pulsed Nd:YAG (1064 nm) and Alexandrite (755 nm) lasers. It was observed that fibers with different designs showed a significant difference in performance at these wavelengths. We will also report a correlation of damage to the fibers between the two laser wavelengths. The performance analyses of different fiber types under the given test conditions will enable optimization of fiber design for specific applications.

  7. Regolith layering processes based on studies of low-temperature volatile elements in Apollo core samples

    NASA Technical Reports Server (NTRS)

    Jovanovic, S.; Reed, G. W., Jr.

    1979-01-01

    The concentrations of Hg released at at the most 130 C increase with depth in near-surface samples from cores. This is in response to a daytime thermal gradient with temperatures of approximately 400 K at the surface decreasing to approximately 250 K at greater than 10 cm depth (Keihm and Langseth, 1973). The steepness of the slopes and the depths to which the concentration gradients extend appear to be determined by the color, density and possibly the grain size of the soils. Earlier surface layers can be identified and, in general, are in agreement with other indicators of such layers. Low temperature volatilized Br exhibits trends that parallel those of Hg in a number of cases. This is also true of Br and Hg fractions released in stepwise heating experiments at higher temperatures. The coherence, especially in higher temperature fractions, between these chemically dissimilar elements implies a common physical process of entrapment; possibly one related to the presence of vapor deposits on surfaces and to opening and closing of microcracks and pores.

  8. Polar structure in a ferroelectric bent-core mesogen as studied by second-harmonic generation

    NASA Astrophysics Data System (ADS)

    Araoka, Fumito; Thisayukta, Jirakorn; Ishikawa, Ken; Watanabe, Junji; Takezoe, Hideo

    2002-08-01

    Second-harmonic generation (SHG) measurements have been conducted in the ferroelectric liquid crystalline phase of a chiral bent-core molecule, P-8-OPIMB6*. Well-aligned cells were obtained by applying an electric field parallel to the substrate surfaces. In-plane anisotropy of the SHG signal observed at normal incidence of light shows two- or four-leaf patterns depending on polarization conditions, indicating a ferroelectric uniform structure. The detailed analysis of the data by taking account of optical anisotropy in the SHG active bulk leads to the determination of nonlinear susceptibility tensor components, d333=14.4 pm/V and d311=49.2 pm/V. Using the d coefficients thus determined, the hyperpolarizability tensor components of the molecule are also determined as βzzz=14.5×10-30 esu and βzxx=67.6×10-30 esu. These values well agree with those of the achiral homolog P-12-OPIMB previously determined by hyper-Rayleigh scattering.

  9. Polar structure in a ferroelectric bent-core mesogen as studied by second-harmonic generation.

    PubMed

    Araoka, Fumito; Thisayukta, Jirakorn; Ishikawa, Ken; Watanabe, Junji; Takezoe, Hideo

    2002-08-01

    Second-harmonic generation (SHG) measurements have been conducted in the ferroelectric liquid crystalline phase of a chiral bent-core molecule, P-8-OPIMB6*. Well-aligned cells were obtained by applying an electric field parallel to the substrate surfaces. In-plane anisotropy of the SHG signal observed at normal incidence of light shows two- or four-leaf patterns depending on polarization conditions, indicating a ferroelectric uniform structure. The detailed analysis of the data by taking account of optical anisotropy in the SHG active bulk leads to the determination of nonlinear susceptibility tensor components, d(333)=14.4 pm/V and d(311)=49.2 pm/V. Using the d coefficients thus determined, the hyperpolarizability tensor components of the molecule are also determined as beta(zzz)=14.5 x 10(-30) esu and beta(zxx)=67.6 x 10(-30) esu. These values well agree with those of the achiral homolog P-12-OPIMB previously determined by hyper-Rayleigh scattering. PMID:12241194

  10. 24. A CORE WORKER DISPLAYS THE CORE BOX AND CORES ...

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

    24. A CORE WORKER DISPLAYS THE CORE BOX AND CORES FOR A BRASS GATE VALVE BODY MADE ON A CORE BOX, CA. 1950. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  11. Aqueous poly(amidoamine) dendrimer G3 and G4 generations with several interior cores at pHs 5 and 7: a molecular dynamics simulation study.

    PubMed

    Kavyani, Sajjad; Amjad-Iranagh, Sepideh; Modarress, Hamid

    2014-03-27

    Poly(amidoamine) (PAMAM) dendrimers play an important role in drug delivery systems, because the dendrimers are susceptible to gain unique features with modification of their structure such as changing their terminals or improving their interior core. To investigate the core improvement and the effect of core nature on PAMAM dendrimers, we studied two generations G3 and G4 PAMAM dendrimers with the interior cores of commonly used ethylendiamine (EDA), 1,5-diaminohexane (DAH), and bis(3-aminopropyl) ether (BAPE) solvated in water, as an aqueous dendrimer system, by using molecular dynamics simulation and applying a coarse-grained (CG) dendrimer force field. To consider the electrostatic interactions, the simulations were performed at two protonation states, pHs 5 and 7. The results indicated that the core improvement of PAMAM dendrimers with DAH produces the largest size for G3 and G4 dendrimers at both pHs 5 and 7. The increase in the size was also observed for BAPE core but it was not so significant as that for DAH core. By considering the internal structure of dendrimers, it was found that PAMAM dendrimer shell with DAH core had more cavities than with BAPE core at both pHs 5 and 7. Also the moment of inertia calculations showed that the generation G3 is more open-shaped and has higher structural asymmetry than the generation G4. Possessing these properties by G3, specially due to its structural asymmetry, make penetration of water beads into the dendrimer feasible. But for higher generation G4 with its relatively structural symmetry, the encapsulation efficiency for water molecules can be enhanced by changing its core to DAH or BAPE. It is also observed that for the higher generation G4 the effect of core modification is more profound than G3 because the core modification promotes the structural asymmetry development of G4 more significantly. Comparing the number of water beads that penetrate into the PAMAM dendrimers for EDA, DAH, and BAPE cores indicates a

  12. Regional tectonic implications of seismic reflection, gravity, structural, and stratigraphic data from New Appalachian Ultradeep Core Hole (ADCOH) site study

    SciTech Connect

    Hatcher, R.D.; Williams, R.T.; Costain, J.K.; Phinney, R.A.; Hopson, J.L.; Stieve, A.L.; Roy-Chowdhury, K.

    1986-05-01

    The Appalachian Ultradeep Core Hole (ADCOH) site study area is located in the eastern Blue Ridge Mountains and western Piedmont of the Carolinas and northeastern Georgia. The goal of the proposed project is an ultradeep core hole that would penetrate and prove the existence of the main detachment thrust of the Blue Ridge-Piedmont (BRP) thrust sheet. Intermediate objectives include study of higher level faults and rock units within the thrust sheet, as well as investigation of the Paleozoic platform cover and basement beneath the BRP thrust sheet. Site study data have revealed that the level of the main BRP detachment may have shallowed rapidly west of the Brevard fault zone, possibly bringing lower Paleozoic carbonate platform rocks to within 3-4 km of the surface near Hayesville, North Carolina, in a large duplex structure. If so, there are implications here and farther west for possible hydrocarbon accumulations. Duplex structure appears to be a dominant style of deformation both within and beneath the BRP thrust sheet. A recently discovered shear zone on the Tallulah Falls dome may represent an imbricate from one of the blind duplexes.

  13. Harmonising data collection from osteoarthritis studies to enable stratification: recommendations on core data collection from an Arthritis Research UK clinical studies group

    PubMed Central

    Corp, Nadia; Watt, Fiona E.; Felson, David T.; O’Neill, Terence W.; Holt, Cathy A.; Jones, Richard K.; Conaghan, Philip G.; Arden, Nigel K.

    2016-01-01

    Objective. Treatment of OA by stratifying for commonly used and novel therapies will likely improve the range of effective therapy options and their rational deployment in this undertreated, chronic disease. In order to develop appropriate datasets for conducting post hoc analyses to inform approaches to stratification for OA, our aim was to develop recommendations on the minimum data that should be recorded at baseline in all future OA interventional and observational studies. Methods. An Arthritis Research UK study group comprised of 32 experts used a Delphi-style approach supported by a literature review of systematic reviews to come to a consensus on core data collection for OA studies. Results. Thirty-five systematic reviews were used as the basis for the consensus group discussion. For studies with a primary structural endpoint, core domains for collection were defined as BMI, age, gender, racial origin, comorbidities, baseline OA pain, pain in other joints and occupation. In addition to the items generalizable to all anatomical sites, joint-specific domains included radiographic measures, surgical history and anatomical factors, including alignment. To demonstrate clinical relevance for symptom studies, the collection of mental health score, self-efficacy and depression scales were advised in addition to the above. Conclusions. Currently it is not possible to stratify patients with OA into therapeutic groups. A list of core and optional data to be collected in all OA interventional and observational studies was developed, providing a basis for future analyses to identify predictors of progression or response to treatment. PMID:27084310

  14. Luminescence, lifetime, and quantum yield studies of redispersible Eu3+-doped GdPO4 crystalline nanoneedles: Core-shell and concentration effects

    NASA Astrophysics Data System (ADS)

    Yaiphaba, N.; Ningthoujam, R. S.; Singh, N. Shanta; Vatsa, R. K.; Singh, N. Rajmuhon; Dhara, Sangita; Misra, N. L.; Tewari, R.

    2010-02-01

    Crystalline nanoneedles of Eu3+-doped GdPO4 and Eu3+-doped GdPO4 covered with GdPO4 shell (core shell) have been prepared at relatively low temperature of 150 °C in ethylene glycol medium. From luminescence study, asymmetric ratio of Eu3+ emission at 612 nm (electric dipole transition) to 592 nm (magnetic dipole transition) is found to be less than one. Maximum luminescence was observed from the nanoparticles with Eu3+ concentration of 5 at. %. For a fixed concentration of Eu3+ doping, there is an improvement in emission intensity for core-shell nanoparticles compared to that for core. This has been attributed to effective removal of surface inhomogeneities around Eu3+ ions present on the surface of core as well as the passivation of inevitable surface states, defects or capping ligand (ethylene glycol) of core nanoparticles by bonding to the shell. Lifetime for D50 level of Eu3+ was found to increase three times for core-shell nanoparticles compared to that for core confirming the more Eu3+ ions with symmetry environment in core shell. For 5 at. % Eu3+-doped GdPO4, quantum yield of 19% is obtained. These nanoparticles are redispersible in water, ethanol, or chloroform and thus will be useful in biological labeling. The dispersed particles are incorporated in polymer-based films that will be useful in display devices.

  15. Photoacoustic Imaging of Breast Microcalcifications: A Preliminary Study with 8-Gauge Core-Biopsied Breast Specimens

    PubMed Central

    Kim, Ga Ram; Kang, Jeeun; Kwak, Jin Young; Chang, Jin Ho; Kim, Seung Il; Youk, Ji Hyun; Moon, Hee Jung; Kim, Min Jung; Kim, Eun-Kyung

    2014-01-01

    Background We presented the photoacoustic imaging (PAI) tool and to evaluate whether microcalcifications in breast tissue can be detected on photoacoustic (PA) images. Methods We collected 21 cores containing microcalcifications (n = 11, microcalcification group) and none (n = 10, control group) in stereotactic or ultrasound (US) guided 8-gauge vacuum-assisted biopsies. Photoacoustic (PA) images were acquired through ex vivo experiments by transmitting laser pulses with two different wavelengths (700 nm and 800 nm). The presence of microcalcifications in PA images were blindly assessed by two radiologists and compared with specimen mammography. A ratio of the signal amplitude occurring at 700 nm to that occurring at 800 nm was calculated for each PA focus and was called the PAI ratio. Results Based on the change of PA signal amplitude between 700 nm and 800 nm, 10 out of 11 specimens containing microcalcifications and 8 out of 10 specimens without calcifications were correctly identified on blind review; the sensitivity, specificity, accuracy, positive predictive and negative predictive values of our blind review were 90.91%, 80.0%, 85.71%, 83.33% and 88.89%. The PAI ratio in the microcalcification group was significantly higher than that in the control group (the median PAI ratio, 2.46 versus 1.11, respectively, P = .001). On subgroup analysis in the microcalcification group, neither malignant diagnosis nor the number or size of calcification-foci was proven to contribute to PAI ratios. Conclusion Breast microcalcifications generated distinguishable PA signals unlike breast tissue without calcifications. So, PAI, a non-ionizing and non-invasive hybrid imaging technique, can be an alternative in overcoming the limitations of conventional US imaging. PMID:25153128

  16. A study of core Thomson scattering measurements in ITER using a multi-laser approach

    NASA Astrophysics Data System (ADS)

    Kurskiev, G. S.; Sdvizhenskii, P. A.; Bassan, M.; Andrew, P.; Bazhenov, A. N.; Bukreev, I. M.; Chernakov, P. V.; Kochergin, M. M.; Kukushkin, A. B.; Kukushkin, A. S.; Mukhin, E. E.; Razdobarin, A. G.; Samsonov, D. S.; Semenov, V. V.; Tolstyakov, S. Yu.; Kajita, S.; Masyukevich, S. V.

    2015-05-01

    The electron component is the main channel for anomalous power loss and the main indicator of transient processes in the tokamak plasma. The electron temperature and density profiles mainly determine the operational mode of the machine. This imposes demanding requirements on the precision and on the spatial and temporal resolution of the Thomson scattering (TS) measurements. Measurements of such high electron temperature with good accuracy in a large fusion device such as ITER using TS encounter a number of physical problems. The 40 keV TS spectrum has a significant blue shift. Due to the transmission functions of the fibres and to their darkening that can occur under a strong neutron irradiation, the operational wavelength range is bounded on the blue side. For example, high temperature measurements become impossible with the 1064 nm probing wavelength since the TS signal within the boundaries of the operational window weakly depends on Te. The second problem is connected with the TS calibration. The TS system for a large fusion machine like ITER will have a set of optical components inaccessible for maintenance, and their spectral characteristics may change with time. Since the present concept of the TS system for ITER relies on the classical approach to measuring the shape of the scattered spectra using wide spectral channels, the diagnostic will be very sensitive to the changes in the optical transmission. The third complication is connected with the deviation of the electron velocity distribution function from a Maxwellian that can happen under a strong ECRH/ECCD, and it may additionally hamper the measurements. This paper analyses the advantages of a ‘multi-laser approach’ implementation for the current design of the core TS system. Such an approach assumes simultaneous plasma probing with different wavelengths that allows the measurement accuracy to be improved significantly and to perform the spectral calibration of the TS system. Comparative analysis

  17. The overall impairment of core executive function components in patients with amnestic mild cognitive impairment: a cross-sectional study

    PubMed Central

    2012-01-01

    Background It remains unclear how executive function (EF) is affected in the stage of amnestic mild cognitive impairment (aMCI). Previous studies using different methods to assess EF in patients with aMCI have reached inconsistent conclusions. The aim of the study was to explore the characteristics of EF impairments in patients with aMCI. Methods We investigated three core components of EF (i.e., working memory, response inhibition and task switching) based on the theoretical model of EF proposed by Miyake et al. (2000) in 34 aMCI patients and 36 healthy elderly controls using computerized tasks programmed with E-prime (the 2-back task and the keep track task for working memory, the stop-signal task and the Stroop task for response inhibition and the more-odd shifting task for task switching). The overall EF and the three individual EF components were compared between groups. For EF components that were impaired, the extent of impairment was compared using a paired analysis. The aMCI group was further divided into EF-intact and EF-deficit groups according to their performances on the EF tests in clinical neuropsychological assessments. We tested for group differences among the normal controls and the EF-intact and EF-deficit aMCI groups and paid special attention to the comparisons between the EF-intact aMCI group and the control group. Results Compared to the control group, overall EF was significantly impaired in patients with aMCI (Wilks’ λ=0.572,P<0.001). Four tasks (the 2-back task, the keep track task, the stop-signal task and the more-odd shifting task) that tapped the three core components of EF displayed group differences that favored the normal controls. The results of the Stroop task revealed no differences in performance between the two groups. The EF-intact aMCI patients also exhibited significantly impaired capabilities in the four tasks compared to the normal controls. There were no significant differences in the extent of impairment between the

  18. Core-shell structured square mixed-spin-2 and 3/2 Ising nanowire on the Bethe lattice: a Monte Carlo study

    NASA Astrophysics Data System (ADS)

    Masrour, R.; Jabar, A.; Hamedoun, M.; Benyoussef, A.

    2016-08-01

    The magnetic properties of square Ising nanowire on the Bethe lattice with core-shell structure consisting of spin-2 at the center and four spin-3/2 at the corners are studied by Monte Carlo simulation. The core-shell structured model is studied using exchange interactions between surface spins (Jss ), between core spins (J σσ ) and between surface and core spins (J S σ ) and crystal field interaction (Δ) at the sites of spin-2 and spin-3/2. The critical temperature is deduced for different layers (N) and different shell-shell exchange interactions. The variation of magnetization with the reduced crystal field and exchange interactions on square Ising nanowire on the Bethe lattice has been studied with effect of other physical parameters. The magnetic hysteresis cycle is studied with different parameters such as: temperature, crystal field and shell-shell exchange interactions. The multiple hysteresis cycles are found.

  19. The Comparison of Shear Bond Strength Between Fibre Reinforced Composite Posts with Three Different Composite Core Materials – An In vitro Study

    PubMed Central

    Anche, Sampath; Kakarla, Pranitha; Kadiyala, Krishna Kishore; Sreedevi, B.; Chiramana, Sandeep; Dev J., Ravi Rakesh; Manne, Sanjay Dutt; G., Deepthi

    2014-01-01

    Aim: The aim of this study is to compare the shear bond strength between fiber reinforced composite post with three different composite core materials. Materials and Methods: The materials used for the study were: 30 maxillary central incisors, pre fabricated fiber reinforced composite post (postec plus posts), Multi-core heavy body, Ti-core, Fluoro-core, Etchant gel, Silane coupling agent, Dentin bonding agent, Standardized gutta percha points, Rely-X dual cure composite resin. A total of 30 human maxillary central incisor were selected for this study. They were divided into three groups of 10 specimens each namely A, B and C. Results: The results obtained were analyzed by using one way analysis (ANOVA) and Tukey Honestly Significant Difference and they showed highest mean shear bond strength for group C when compared with group A and group B. There is no significant difference in the shear bond strength values between group A and group B. Conclusion: The teeth restored with multicore HB showed highest shear bond strength. The teeth restored with Fluoro core showed lowest shear bond strength. No statistically significant difference exists between the shear bond strength values between Ti-core and Fluoro-core. PMID:24596784

  20. A case study of full integration of the arts into core subject area instruction in one East Texas secondary school

    NASA Astrophysics Data System (ADS)

    Leysath, Maggie

    This exploratory phenomenological case study investigated the influence the full integration of the arts into core subject instruction has on classroom environment, student academic achievement, and student engagement as perceived by administrators, teachers, and students in one East Texas secondary school. Participant interviews were analyzed using Creswell's (2012) six-step method for analyzing phenomenological studies. The researcher implemented three learning activities in which ceramics learning objectives were fully integrated with chemistry learning objectives. The first activity combined clay properties and pottery wheel throwing with significant numbers. The second activity combined glaze formulation with moles. The third combined stoichiometry with the increased glaze formula for students to glaze the bowls they made. Findings suggest the full integration of art in core subject area instruction has numerous positive effects. Participants reported improved academic achievement for all students including reluctant learners. Students, teachers, and the administrator reported greater participation in the art integrated activities. Participants perceived a need for further training for teachers and administrators for greater success.

  1. Satellite infrared observations of Kuroshio warm-core rings and their application to study of Pacific saury migration

    NASA Astrophysics Data System (ADS)

    Saitoh, Sei-ichi; Kosaka, Sunao; Iisaka, Joji

    1986-11-01

    Satellite infrared observations of Kuroshio warm-core rings (KWCRs), made in the Tohoku area west of 150°E from February 1980 to June 1981, were used to study the effect of ring distributions on the migration routes of the epi-pelagic and migratory fish Pacific saury. Cololabis saira (Brevoort). The movement and mean speed of three KWCRs and a Tsugaru warm current gyre were determined in the study area. KWCRs tended to drift to the north or to the east at a mean speed of 5 cm s -1. This drift speed is similar to that of Gulf Stream warm-core rings, but the drift direction is quite different from the westward drift in the Gulf Stream system. A comparison between distribution of KWCRs and distribution of fish schools suggests that the KWCRs control southward migration routes of Pacific saury through interaction with the surrounding cold waters such as the First and Second Oyashio Intrusions. Satellite infrared monitoring of KWCRs and the surrounding cold waters have proved to be useful for the short period prediction of Pacific saury fishing ground formation.

  2. The dynamic mechanical properties study on the sandwich panel of different thickness steel plate-foam aluminum core

    NASA Astrophysics Data System (ADS)

    Chang, Zhongliang; Zou, Guangping; Zhao, Weiling; Xia, Peixiu

    2009-12-01

    The foam aluminum belongs to multi-cell materials, and it has good mechanical performance, such as large deformation capacity and good energy absorption, and usually used as core material of sandwich panel, now it is widely used in automotive, aviation, aerospace and other fields, particularly suitable for various anti-collision structure and buffer structure. In this article, based on an engineering background, the INSTRON4505 electronic universal testing machine and split Hopkinson pressure bar (SHPB) were used for testing the static and dynamic mechanical properties of sandwich panel with different thickness steel plate- foam aluminum core, from the results we can see that the steel plate thickness has big influence on the stress-strain curve of the sandwich panel, and also takes the sandwich panel with 1mm steel panel to study the material strain rate dependence which under different high shock wave stress loaded, the results show that the sandwich panel is strain rate dependence material. And also, in order to get good waveforms in the SHPB experiment, the waveform shaped technique is used in the dynamic experiments, and the study of this paper will good to sandwich panel used in the engineering.

  3. Design Study for a Low-Enriched Uranium Core for the High Flux Isotope Reactor, Annual report for FY 2009

    SciTech Connect

    Chandler, David; Freels, James D; Ilas, Germina; Miller, James Henry; Primm, Trent; Sease, John D; Guida, Tracey; Jolly, Brian C

    2010-02-01

    This report documents progress made during FY 2009 in studies of converting the High Flux Isotope Reactor (HFIR) from high enriched uranium (HEU) fuel to low enriched uranium (LEU) fuel. Conversion from HEU to LEU will require a change in fuel form from uranium oxide to a uranium-molybdenum alloy. With axial and radial grading of the fuel foil and an increase in reactor power to 100 MW, calculations indicate that the HFIR can be operated with LEU fuel with no degradation in reactor performance from the current level. Results of selected benchmark studies imply that calculations of LEU performance are accurate. Studies are reported of the application of a silicon coating to surrogates for spheres of uranium-molybdenum alloy. A discussion of difficulties with preparing a fuel specification for the uranium-molybdenum alloy is provided. A description of the progress in developing a finite element thermal hydraulics model of the LEU core is provided.

  4. Mercury's core evolution

    NASA Astrophysics Data System (ADS)

    Deproost, Marie-Hélène; Rivoldini, Attilio; Van Hoolst, Tim

    2016-10-01

    Remote sensing data of Mercury's surface by MESSENGER indicate that Mercury formed under reducing conditions. As a consequence, silicon is likely the main light element in the core together with a possible small fraction of sulfur. Compared to sulfur, which does almost not partition into solid iron at Mercury's core conditions and strongly decreases the melting temperature, silicon partitions almost equally well between solid and liquid iron and is not very effective at reducing the melting temperature of iron. Silicon as the major light element constituent instead of sulfur therefore implies a significantly higher core liquidus temperature and a decrease in the vigor of compositional convection generated by the release of light elements upon inner core formation.Due to the immiscibility in liquid Fe-Si-S at low pressure (below 15 GPa), the core might also not be homogeneous and consist of an inner S-poor Fe-Si core below a thinner Si-poor Fe-S layer. Here, we study the consequences of a silicon-rich core and the effect of the blanketing Fe-S layer on the thermal evolution of Mercury's core and on the generation of a magnetic field.

  5. Tephrostratigraphic studies on a sediment core from Lake Prespa in the Balkans

    NASA Astrophysics Data System (ADS)

    Damaschke, M.; Sulpizio, R.; Zanchetta, G.; Wagner, B.; Böhm, A.; Nowaczyk, N.; Rethemeyer, J.; Hilgers, A.

    2012-09-01

    A detailed tephrostratigraphic record, which dates back to Marine Isotope Stage (MIS) 5, has been established from a 17.76 m long core (Co1215) from Lake Prespa (Macedonia, Albania and Greece). A total of eleven tephra and cryptotephra layers (PT0915-1 to PT0915-11) were identified, using XRF scanning, magnetic susceptibility measurements, and macro- and microscopic inspection of the sediments. The major element composition of glass shards and/or micro-pumice fragments indicates that the tephras and cryptotephras originate from the explosive volcanism of Italy. Eight tephra and cryptotephra layers were correlated with specific volcanic eruptions: cryptotephra PT0915-1 with the 512 AD eruption of Somma-Vesuvius (1438 cal yr BP), tephra PT0915-2 with the Mercato eruption of Somma-Vesuvius (8890 ± 90 cal yr BP), cryptotephras PT0915-3 and PT0915-4 with Tufi Biancastri/LN1-LN2 of the Campi Flegrei (14 749 ± 523 cal yr BP and 15 551 ± 621 cal yr BP), tephra PT0915-5 with the SMP1-e/Y-3 eruption of the Campi Flegrei (30 000-31 000 cal yr BP), tephra PT0915-7 with the Campanian Ignimbrite/Y-5 of the Campi Flegrei (39 280 ± 110 cal yr BP), cryptotephra PT0915-8 with the SMP1-a event of Ischia Island (around 44 000 cal yr BP) and tephra PT0915-9 with the Green Tuff/Y-6 eruption of Pantelleria Island (around 45 000 cal yr BP). Tephra PT0915-11 could be attributed to the volcanic activity of Mount Etna, but probably represents a hitherto unknown eruption at ca. 60 000 cal yr BP. Cryptotephras PT0915-6 and PT0915-10 remain unclassified so far, but according to the presented age-depth model these would have been deposited around 35 000 and 48 500 cal yr BP, respectively. Some of the tephras and cryptotephras are recognised for the first time in the Balkan region. The tephrostratigraphic work provides important information about ash dispersal and explosion patterns of source volcanoes and can be used to correlate and date geographically distant paleoenvironmental and

  6. Tephrostratigraphic studies on a sediment core from Lake Prespa in the Balkans

    NASA Astrophysics Data System (ADS)

    Damaschke, M.; Sulpizio, R.; Zanchetta, G.; Wagner, B.; Böhm, A.; Nowaczyk, N.; Rethemeyer, J.; Hilgers, A.

    2013-01-01

    A detailed tephrostratigraphic record, which dates back to Marine Isotope Stage (MIS) 5b (ca. 91 kyr), has been established from a 17.76 m long core (Co1215) from Lake Prespa (Macedonia, Albania and Greece). A total of eleven tephra and cryptotephra layers (PT0915-1 to PT0915-11) were identified, using XRF scanning, magnetic susceptibility measurements, and macro- and microscopic inspection of the sediments. The major element composition of glass shards and/or micro-pumice fragments indicates that the tephras and cryptotephras originate from the explosive volcanism of Italy. Eight tephra and cryptotephra layers were correlated with specific volcanic eruptions: the AD 512 eruption of Somma-Vesuvius (1438 cal yr BP), the Mercato eruption of Somma-Vesuvius (8890 ± 90 cal yr BP), the Tufi Biancastri/LN1-LN2 eruption of the Campi Flegrei (14 749 ± 523 cal yr BP and 15 551 ± 621 cal yr BP), the SMP1-e/Y-3 eruption of the Campi Flegrei (30 000-31 000 cal yr BP), the Campanian Ignimbrite/Y-5 eruption of the Campi Flegrei (39 280 ± 110 cal yr BP), the SMP1-a event of Ischia Island (around 44 000 cal yr BP) and the Green Tuff/Y-6 eruption of Pantelleria Island (around 45 000 cal yr BP). One tephra could be attributed to the volcanic activity of Mount Etna, but probably represents an unknown eruption at ca. 60 000 cal yr BP. Cryptotephras PT0915-6 and PT0915-10 remain unclassified so far, but according to the presented age-depth model these would have been deposited around 35 000 and 48 500 cal yr BP, respectively. Some of the tephras and cryptotephras are recognised for the first time in the Balkan region. The tephrostratigraphic work provides important information about ash dispersal and explosion patterns of source volcanoes and can be used to correlate and date geographically distant paleoenvironmental and archaeological archives in the central Mediterranean region. Moreover, the tephrostratigraphic work in combination with radiocarbon and electron spin resonance (ESR

  7. Application of Core Dynamics Modeling to Core-Mantle Interactions

    NASA Technical Reports Server (NTRS)

    Kuang, Weijia

    2003-01-01

    Observations have demonstrated that length of day (LOD) variation on decadal time scales results from exchange of axial angular momentum between the solid mantle and the core. There are in general four core-mantle interaction mechanisms that couple the core and the mantle. Of which, three have been suggested likely the dominant coupling mechanism for the decadal core-mantle angular momentum exchange, namely, gravitational core-mantle coupling arising from density anomalies in the mantle and in the core (including the inner core), the electromagnetic coupling arising from Lorentz force in the electrically conducting lower mantle (e.g. D-layer), and the topographic coupling arising from non-hydrostatic pressure acting on the core-mantle boundary (CMB) topography. In the past decades, most effort has been on estimating the coupling torques from surface geomagnetic observations (kinematic approach), which has provided insights on the core dynamical processes. In the meantime, it also creates questions and concerns on approximations in the studies that may invalidate the corresponding conclusions. The most serious problem is perhaps the approximations that are inconsistent with dynamical processes in the core, such as inconsistencies between the core surface flow beneath the CMB and the CMB topography, and that between the D-layer electric conductivity and the approximations on toroidal field at the CMB. These inconsistencies can only be addressed with numerical core dynamics modeling. In the past few years, we applied our MoSST (Modular, Scalable, Self-consistent and Three-dimensional) core dynamics model to study core-mantle interactions together with geodynamo simulation, aiming at assessing the effect of the dynamical inconsistencies in the kinematic studies on core-mantle coupling torques. We focus on topographic and electromagnetic core-mantle couplings and find that, for the topographic coupling, the consistency between the core flow and the CMB topography is

  8. Novel copper (Cu) loaded core-shell silica nanoparticles with improved Cu bioavailability: synthesis, characterization and study of antibacterial properties.

    PubMed

    Maniprasad, Pavithra; Santra, Swadeshmukul

    2012-08-01

    We report synthesis of a novel core-shell silica based antimicrobial nanoparticles where the silica shell has been engineered to accommodate copper (Cu). Synthesis of the core-shell Cu-silica nanoparticle (C-S CuSiO2NP) involves preparation of base-hydrolyzed Stöber silica "seed" particles first, followed by the acid-catalyzed seeded growth of the Cu-silica shell layer around the core. The Scanning Electron Microscopy (SEM) and the Transmission Electron Microscopy (TEM) measured the seed particle size to be -380 nm and the shell thickness to be -35 nm. The SEM particle characterization confirms formation of highly monodispersed particles with smooth surface morphology. Characterization of particle size distribution in solution by Dynamic Light Scattering (DLS) technique was fairly consistent with the electron microscopy results. Loading of Cu to nanoparticles was confirmed by the SEM-Energy Dispersive X-Ray Spectroscopy (EDS) and Atomic Absorption Spectroscopy (AAS). The Cu loading was estimated to be 0.098 microg of metallic copper per mg of C-S CuSiO2NP material by the AAS technique. Antibacterial efficacy of C-S CuSiO2NP was evaluated against E. coli and B. subtilis using Cu hydroxide ("Insoluble" Cu compound, sub-micron size particles) as positive control and silica "seed" particles (without Cu loading) as negative control. Bacterial growth in solution was measured against different concentrations of C-S CuSiO2NP to determine the Minimum Inhibitory Concentration (MIC) value. The estimated MIC values were 2.4 microg metallic Cu/mL for both E. coli and B. subtilis. Bac-light fluorescence microscopy based assay was used to count relative population of the live and dead bacteria cells. Antibacterial study clearly shows that C-S CuSiO2NP is more effective than insoluble Cu hydroxide particles at equivalent metallic Cu concentration, suggesting improvement of Cu bioavailability (i.e., more soluble Cu) in C-SCuSiO2NP material due to its core-shell design. PMID

  9. Childhood Trauma and Adult Interpersonal Functioning: A Study Using the Core Conflictual Relationship Theme Method (CCRT)

    ERIC Educational Resources Information Center

    Drapeau, M.; Perry, J.C.

    2004-01-01

    Objective: This study aimed to examine the long-term correlates of childhood trauma in regard to interpersonal functioning in adulthood. Method: One hundred and nineteen (N=119) subjects from the Austen Riggs Follow-along Study were included in the study. The Traumatic Antecedent Interview scoring method was used to assess 10 types of childhood…

  10. Challenges in Enacting Core Practices in Language Teacher Education: A Self-Study

    ERIC Educational Resources Information Center

    Peercy, Megan Madigan

    2014-01-01

    In this study, I explore my practices as a teacher educator in one course both before and after returning to the K-12 classroom to teach secondary language learners for one academic year. By examining the intersection of self-study and practice-based teacher education, I illustrate how I used self-study as a mechanism for innovation and change and…

  11. Labeling the oily core of nanocapsules and lipid-core nanocapsules with a triglyceride conjugated to a fluorescent dye as a strategy to particle tracking in biological studies

    NASA Astrophysics Data System (ADS)

    Fiel, Luana Almeida; Contri, Renata Vidor; Bica, Juliane Freitas; Figueiró, Fabrício; Battastini, Ana Maria Oliveira; Guterres, Sílvia Stanisçuaski; Pohlmann, Adriana Raffin

    2014-05-01

    The synthesis of novel fluorescent materials represents a very important step to obtain labeled nanoformulations in order to evaluate their biological behavior. The strategy of conjugating a fluorescent dye with triacylglycerol allows that either particles differing regarding supramolecular structure, i.e., nanoemulsions, nanocapsules, lipid-core nanocapsules, or surface charge, i.e., cationic nanocapsules and anionic nanocapsules, can be tracked using the same labeled material. In this way, a rhodamine B-conjugated triglyceride was obtained to prepare fluorescent polymeric nanocapsules. Different formulations were obtained, nanocapsules (NC) or lipid-core nanocapsules (LNC), using the labeled oil and Eudragit RS100, Eudragit S100, or poly(caprolactone) (PCL), respectively. The rhodamine B was coupled with the ricinolein by activating the carboxylic function using a carbodiimide derivative. Thin layer chromatography, proton nuclear magnetic resonance (1H-NMR), Fourier transform infrared spectroscopy (FTIR), UV-vis, and fluorescence spectroscopy were used to identify the new product. Fluorescent nanocapsule aqueous suspensions were prepared by the solvent displacement method. Their pH values were 4.6 (NC-RS100), 3.5 (NC-S100), and 5.0 (LNC-PCL). The volume-weighted mean diameter ( D 4.3) and polydispersity values were 150 nm and 1.05 (NC-RS100), 350 nm and 2.28 (NC-S100), and 270 nm and 1.67 (LNC-PCL). The mean diameters determined by photon correlation spectroscopy (PCS) ( z-average) were around 200 nm. The zeta potential values were +5.85 mV (NC-RS100), -21.12 mV (NC-S100), and -19.25 mV (LNC-PCL). The wavelengths of maximum fluorescence emission were 567 nm (NC-RS100 and LNC-PCL) and 574 nm (NC-S100). Fluorescence microscopy was used to evaluate the cell uptake (human macrophage cell line) of the fluorescent nanocapsules in order to show the applicability of the approach. When the cells were treated with the fluorescent nanocapsules, red emission was detected

  12. Labeling the oily core of nanocapsules and lipid-core nanocapsules with a triglyceride conjugated to a fluorescent dye as a strategy to particle tracking in biological studies

    PubMed Central

    2014-01-01

    The synthesis of novel fluorescent materials represents a very important step to obtain labeled nanoformulations in order to evaluate their biological behavior. The strategy of conjugating a fluorescent dye with triacylglycerol allows that either particles differing regarding supramolecular structure, i.e., nanoemulsions, nanocapsules, lipid-core nanocapsules, or surface charge, i.e., cationic nanocapsules and anionic nanocapsules, can be tracked using the same labeled material. In this way, a rhodamine B-conjugated triglyceride was obtained to prepare fluorescent polymeric nanocapsules. Different formulations were obtained, nanocapsules (NC) or lipid-core nanocapsules (LNC), using the labeled oil and Eudragit RS100, Eudragit S100, or poly(caprolactone) (PCL), respectively. The rhodamine B was coupled with the ricinolein by activating the carboxylic function using a carbodiimide derivative. Thin layer chromatography, proton nuclear magnetic resonance (1H-NMR), Fourier transform infrared spectroscopy (FTIR), UV-vis, and fluorescence spectroscopy were used to identify the new product. Fluorescent nanocapsule aqueous suspensions were prepared by the solvent displacement method. Their pH values were 4.6 (NC-RS100), 3.5 (NC-S100), and 5.0 (LNC-PCL). The volume-weighted mean diameter (D4.3) and polydispersity values were 150 nm and 1.05 (NC-RS100), 350 nm and 2.28 (NC-S100), and 270 nm and 1.67 (LNC-PCL). The mean diameters determined by photon correlation spectroscopy (PCS) (z-average) were around 200 nm. The zeta potential values were +5.85 mV (NC-RS100), -21.12 mV (NC-S100), and -19.25 mV (LNC-PCL). The wavelengths of maximum fluorescence emission were 567 nm (NC-RS100 and LNC-PCL) and 574 nm (NC-S100). Fluorescence microscopy was used to evaluate the cell uptake (human macrophage cell line) of the fluorescent nanocapsules in order to show the applicability of the approach. When the cells were treated with the fluorescent nanocapsules, red emission was

  13. Labeling the oily core of nanocapsules and lipid-core nanocapsules with a triglyceride conjugated to a fluorescent dye as a strategy to particle tracking in biological studies.

    PubMed

    Fiel, Luana Almeida; Contri, Renata Vidor; Bica, Juliane Freitas; Figueiró, Fabrício; Battastini, Ana Maria Oliveira; Guterres, Sílvia Stanisçuaski; Pohlmann, Adriana Raffin

    2014-01-01

    The synthesis of novel fluorescent materials represents a very important step to obtain labeled nanoformulations in order to evaluate their biological behavior. The strategy of conjugating a fluorescent dye with triacylglycerol allows that either particles differing regarding supramolecular structure, i.e., nanoemulsions, nanocapsules, lipid-core nanocapsules, or surface charge, i.e., cationic nanocapsules and anionic nanocapsules, can be tracked using the same labeled material. In this way, a rhodamine B-conjugated triglyceride was obtained to prepare fluorescent polymeric nanocapsules. Different formulations were obtained, nanocapsules (NC) or lipid-core nanocapsules (LNC), using the labeled oil and Eudragit RS100, Eudragit S100, or poly(caprolactone) (PCL), respectively. The rhodamine B was coupled with the ricinolein by activating the carboxylic function using a carbodiimide derivative. Thin layer chromatography, proton nuclear magnetic resonance ((1)H-NMR), Fourier transform infrared spectroscopy (FTIR), UV-vis, and fluorescence spectroscopy were used to identify the new product. Fluorescent nanocapsule aqueous suspensions were prepared by the solvent displacement method. Their pH values were 4.6 (NC-RS100), 3.5 (NC-S100), and 5.0 (LNC-PCL). The volume-weighted mean diameter (D 4.3) and polydispersity values were 150 nm and 1.05 (NC-RS100), 350 nm and 2.28 (NC-S100), and 270 nm and 1.67 (LNC-PCL). The mean diameters determined by photon correlation spectroscopy (PCS) (z-average) were around 200 nm. The zeta potential values were +5.85 mV (NC-RS100), -21.12 mV (NC-S100), and -19.25 mV (LNC-PCL). The wavelengths of maximum fluorescence emission were 567 nm (NC-RS100 and LNC-PCL) and 574 nm (NC-S100). Fluorescence microscopy was used to evaluate the cell uptake (human macrophage cell line) of the fluorescent nanocapsules in order to show the applicability of the approach. When the cells were treated with the fluorescent nanocapsules, red emission was

  14. Study of the Ti44(α,p)V47 reaction and implications for core collapse supernovae

    NASA Astrophysics Data System (ADS)

    Margerin, V.; Murphy, A. St. J.; Davinson, T.; Dressler, R.; Fallis, J.; Kankainen, A.; Laird, A. M.; Lotay, G.; Mountford, D. J.; Murphy, C. D.; Seiffert, C.; Schumann, D.; Stowasser, T.; Stora, T.; Wang, C. H.-T.; Woods, P. J.

    2014-04-01

    The underlying physics triggering core collapse supernovae is not fully understood but observations of material ejected during such events helps to solve this puzzle. In particular, several satellite based γ-ray observations of the isotope 44Ti have been reported recently. Conveniently, the amount of this isotope in stellar ejecta is thought to depend critically on the explosion mechanism. The most influential reaction to the amount of 44Ti in supernovae is Ti44(α,p)V47. Here we report on a direct study of this reaction conducted at the REX-ISOLDE facility, CERN. The experiment was performed with a 44Ti beam at E=2.16 MeV/u, corresponding to an energy distribution, for reacting α-particles, centred on E=4.15 with a 1σ width of 0.23 MeV. This is, for the first time, well within the Gamow window for core collapse supernovae. The material from which the 44Ti beam was extracted originates from highly irradiated components of the SINQ spallation neutron source of the Paul Scherrer Institute. No yield above background was observed, enabling an upper limit for the rate of this reaction to be determined. This result is below expectation, suggesting that the Ti44(α,p)V47 reaction proceeds more slowly than previously thought. Implications for astrophysical events, and remnant age, are discussed.

  15. Occupied and unoccupied electronic structures of an L-cysteine film studied by core-absorption and resonant photoelectron spectroscopies

    NASA Astrophysics Data System (ADS)

    Kamada, M.; Hideshima, T.; Azuma, J.; Yamamoto, I.; Imamura, M.; Takahashi, K.

    2016-04-01

    Unoccupied and occupied electronic structures of an L-cysteine film have been studied by absorption and resonant photoelectron spectroscopies. Core absorptions at S-L, C-K, N-K, and O-K levels indicate that the lower unoccupied states are predominantly composed of oxygen-2p, carbon-2p, and sulfur-4s+3d orbitals, while higher unoccupied states may be attributed dominantly to nitrogen-np (n ≥ 3), oxygen-np (n ≥ 3), and sulfur-ns+md (n ≥ 4, m ≥ 3) orbitals. Resonant photoelectron spectra at S-L23 and O-K levels indicate that the highest occupied state is originated from sulfur-3sp orbitals, while oxygen-2sp orbitals contribute to the deeper valence states. The delocalization lifetimes of the oxygen-1s and sulfur-2p excited states are estimated from a core-hole clock method to be about 9 ± 1 and 125 ± 25 fs, respectively.

  16. A study on the measurement of the core body temperature change after radiofrequency ablation (RFA) through MR temperature mapping

    NASA Astrophysics Data System (ADS)

    Kim, Chang-Bok; Dong, Kyung-Rae; Yu, Young; Chung, Woon-Kwan; Cho, Jae-Hwan; Joo, Kyu-Ji

    2013-09-01

    This study examined the change in the heat generated during radiofrequency ablation (RFA) using a self-manufactured phantom and used magnetic resonance imaging (MRI) to analyze the change in the temperature of the core body and the tissues surrounding the phantom. In this experiment, the image and the phase image were obtained simultaneously from a gradient echo-based sequence using 1.5-Tesla MRI equipment and a 12-channel head coil. The temperature mapping technique was used to calculate the change in temperature. The regions of interest (ROIs) (ROI 1 - ROI 6) were set with a focus on the area where the RFA was performed, according to the temperature distribution, before monitoring the temperature change for one hour in time intervals of five minutes. The results showed that the temperature change in the ROI with time was largest in the ROI 1 and smallest in the ROI 5. In addition, after the RFA procedure, the temperature decreased from the initial value to 0 °C in one hour. The temperature changes in the core body and the surrounding tissues were confirmed by MRI temperature mapping, which is a noninvasive method.

  17. Characteristic of core materials in polymeric micelles effect on their micellar properties studied by experimental and dpd simulation methods.

    PubMed

    Cheng, Furong; Guan, Xuewa; Cao, Huan; Su, Ting; Cao, Jun; Chen, Yuanwei; Cai, Mengtan; He, Bin; Gu, Zhongwei; Luo, Xianglin

    2015-08-15

    Polymeric micelles are one important class of nanoparticles for anticancer drug delivery, but the impact of hydrophobic segments on drug encapsulation and release is unclear, which deters the rationalization of drug encapsulation into polymeric micelles. This paper focused on studying the correlation between the characteristics of hydrophobic segments and encapsulation of structurally different drugs (DOX and β-carotene). Poly(ϵ-caprolactone) (PCL) or poly(l-lactide) (PLLA) were used as hydrophobic segments to synthesize micelle-forming amphiphilic block copolymers with the hydrophilic methoxy-poly(ethylene glycol) (mPEG). Both blank and drug loaded micelles were spherical in shape with sizes lower than 50 nm. PCL-based micelles exhibited higher drug loading capacity than their PLLA-based counterparts. Higher encapsulation efficiency of β-carotene was achieved compared with DOX. In addition, both doxorubicin and β-carotene were released much faster from PCL-based polymeric micelles. Dissipative particle dynamics (DPD) simulation revealed that the two drugs tended to aggregate in the core of the PCL-based micelles but disperse in the core of PLLA based micelles. In vitro cytotoxicity investigation of DOX loaded micelles demonstrated that a faster drug release warranted a more efficient cancer-killing effect. This research could serve as a guideline for the rational design of polymeric micelles for drug delivery. PMID:26196277

  18. Study of carbonyl iron/poly(butylcyanoacrylate) (core/shell) particles as anticancer drug delivery systems Loading and release properties.

    PubMed

    Arias, José L; Linares-Molinero, Fernando; Gallardo, Visitación; Delgado, Angel V

    2008-03-01

    The aim of this study is to develop a detailed investigation of the capabilities of carbonyl iron/poly(butylcyanoacrylate) (core/shell) particles for the loading and release of 5-Fluorouracil and Ftorafur. The anionic polymerization procedure, used to obtain poly(alkylcyanoacrylate) nanoparticles for drug delivery, was followed in the synthesis of the composite particles, except that the polymerization medium was a carbonyl iron suspension. The influence of the two mechanisms of drug incorporation (entrapment in the polymeric network and surface adsorption) on the drug loading and release profiles were investigated by means of spectrophotometric and electrophoretic measurements. The optimum loading conditions were ascertained and used to perform drug release evaluations. Among the factors affecting drug loading, both pH and drug concentration were found to be the main determining ones. For both drugs, the release profile was found to be biphasic, since the drug adsorbed on the surface was released rather rapidly (close to 100% in 1h), whereas the drug incorporated in the polymer matrix required between 10 and 20h to be fully released. The kinetics of the drug release from the core/shell particles was mainly controlled by the pH of the release medium, the type of drug incorporation, and the amount of drug loaded.

  19. Formation of core-shell Au@Ag nanorods induced by catecholamines: A comparative study and an analytical application.

    PubMed

    Gorbunova, M V; Apyari, V V; Dmitrienko, S G; Garshev, A V

    2016-09-14

    Gold nanorods (AuNRs) stabilized by cetyltrimethylammonium bromide (CTAB) were synthesized and an interaction of catecholamines (CAs) with silver ions in the presence of the obtained AuNRs was studied. The reaction results into formation of core-shell Au@Ag nanorods (Au@AgNRs) and leads to a hypsochromic shift of the long-wave surface plasmon resonance (SPR) band in the absorption spectrum of AuNRs. The influence of a CA structure, excess of CTAB, interaction time, pH, concentration of AuNRs, silver ions and CAs on this interaction was studied. Based on correlation of the NRs spectral characteristics with the concentration of CAs, a method for spectrophotometric determination of dobutamine, epinephrine, norepinephrine and dopamine with detection limits 27, 18, 16 and 13 μg L(-1), respectively, has been developed. The method can be applied to the analysis of medicines. PMID:27566354

  20. Formation of core-shell Au@Ag nanorods induced by catecholamines: A comparative study and an analytical application.

    PubMed

    Gorbunova, M V; Apyari, V V; Dmitrienko, S G; Garshev, A V

    2016-09-14

    Gold nanorods (AuNRs) stabilized by cetyltrimethylammonium bromide (CTAB) were synthesized and an interaction of catecholamines (CAs) with silver ions in the presence of the obtained AuNRs was studied. The reaction results into formation of core-shell Au@Ag nanorods (Au@AgNRs) and leads to a hypsochromic shift of the long-wave surface plasmon resonance (SPR) band in the absorption spectrum of AuNRs. The influence of a CA structure, excess of CTAB, interaction time, pH, concentration of AuNRs, silver ions and CAs on this interaction was studied. Based on correlation of the NRs spectral characteristics with the concentration of CAs, a method for spectrophotometric determination of dobutamine, epinephrine, norepinephrine and dopamine with detection limits 27, 18, 16 and 13 μg L(-1), respectively, has been developed. The method can be applied to the analysis of medicines.

  1. Structural study of a bent-core liquid crystal showing the B{sub 1}-B{sub 2} transition

    SciTech Connect

    Folcia, Cesar Luis; Etxebarria, J.; Ortega, J.; Ros, M. B.

    2006-09-15

    An experimental study of the B{sub 1}-B{sub 2} transition is carried out in a bent-core liquid crystal. The study is essentially based on x-ray measurements as a function of temperature. The B{sub 1}-B{sub 2} transition is extremely unusual and implies a deep structural change from a columnar phase to a lamellar phase. We have found that the B{sub 1} phase in our compound is similar to the so-called B{sub 1} reversed phase, with an additional splay of the polarization in the columns. On approaching the B{sub 2} phase the width of the cross section of the columns increases. The transition is clearly first order, with a large hysteresis though the enthalpy content is very small. A possible mechanism for the transition is briefly sketched.

  2. Influence of dimensionality and interface type on optical and electronic properties of CdS/ZnS core-shell nanocrystals—A first-principles study

    SciTech Connect

    Kocevski, V. E-mail: vancho.kocevski@physics.uu.se; Eriksson, O.; Gerard, C.; Rusz, J.; Sarma, D. D.

    2015-10-28

    Semiconducting nanocrystals (NCs) have become one of the leading materials in a variety of applications, mainly due to their size tunable band gap and high intensity emission. Their photoluminescence (PL) properties can be notably improved by capping the nanocrystals with a shell of another semiconductor, making core-shell structures. We focus our study on the CdS/ZnS core-shell nanocrystals that are closely related to extensively studied CdSe/CdS NCs, albeit exhibiting rather different photoluminescence properties. We employ density functional theory to investigate the changes in the electronic and optical properties of these nanocrystals with size, core/shell ratio, and interface structure between the core and the shell. We have found that both the lowest unoccupied eigenstate (LUES) and the highest occupied eigenstate (HOES) wavefunction (WF) are localized in the core of the NCs, with the distribution of the LUES WF being more sensitive to the size and the core/shell ratio. We show that the radiative lifetimes are increasing, and the Coulomb interaction energies decrease with increasing NC size. Furthermore, we investigated the electronic and optical properties of the NCs with different interfaces between the core and the shell and different core types. We find that the different interfaces and core types have rather small influence on the band gaps and the absorption indexes, as well as on the confinement of the HOES and LUES WFs. Also the radiative lifetimes are found to be only slightly influenced by the different structural models. In addition, we compare these results with the previous results for CdSe/CdS NCs, reflecting the different PL properties of these two types of NCs. We argue that the difference in their Coulomb interaction energies is one of the main reasons for their distinct PL properties.

  3. Stable-isotope studies on ice cores and snow pits in Dronning Maud Land, Antarctica, covering the past 2000 years

    NASA Astrophysics Data System (ADS)

    Oerter, H.; Kipfstuhl, S.; Wilhelms, F.

    2012-12-01

    During the past 15 years various ice cores were drilled at and upstream of Kohnen station (75.0017 S, 0.0678 E, 2882 m a.s.l.) Dronning Maud Land, East Antarctica, supplemented by snow pit studies. These data sets of stable-isotope data (18O, D, deuterium excess d) are available over various time periods displaying centennial and strong decadal variations. 5 ice cores are used to create staked profiles of the deviation of the 18O content from the mean of the period 1259-1816 (an interval well defined by 2 unique volcanic events) for the time slices of the past 2000 and 200 years. For the past 50 years data from various shallow firn cores and snow pits in the area will be presented. The used reference period for the short term studies is 1961-1990. δ18O values may be converted to temperature with the local gradient of 0.77 δ18O-‰/°C. The Common Era follows the Roman period which is characterised by isotope values or temperatures, respectively, higher than observed in the 2000 years afterwards until today. The so-called medieval optimum around 1050-1250 is recognisable. The so-called Little Ice Age, which is attributed to the period 1650-1850 in the Northern hemisphere, is not clearly displayed. Overall, a slight cooling (0.008 δ18O-‰/100a) is evident within the Common Era until 1900. In the time slice of the past 200 years the coldest period occurred between 1875 and 1900. During the 20th century the isotope content and thus the air temperature have been increasing (0.88 δ18O-‰/100a) and reached values in the first decade of the 21st century clearly higher than around 1800 and before. The 1940ies formed the coldest decade in the 20th century, another relative minimum appeared in the 1980ies. The time series with shallow firn cores and snow pits stop at 2008 CE. For the past 50 years it is not possible to determine a trend unambiguously. This is due to the decadal variations and the shortness of the time series from single pits and shallow cores. However

  4. A Value-Added Study of Teacher Spillover Effects across Four Core Subjects in Middle Schools

    ERIC Educational Resources Information Center

    Yuan, Kun

    2015-01-01

    This study examined the existence, magnitude, and impact of teacher spillover effects (TSEs) across teachers of four subject areas (i.e., mathematics, English language arts [ELA], science, and social studies) on student achievement in each of the four subjects at the middle school level. The author conducted a series of value-added (VA) analyses,…

  5. Getting at the Core of Literacy Improvement: A Case Study of an Urban Secondary School

    ERIC Educational Resources Information Center

    Francois, Chantal

    2014-01-01

    Although national trends of urban adolescent reading underachievement suggest that schools are unable to adequately support this population's reading development, some studies have demonstrated that urban schools can operate to raise student achievement, thereby disrupting national trends. In this study, the author investigates one such…

  6. Evaluation of Core Vocabulary Intervention for Treatment of Inconsistent Phonological Disorder: Three Treatment Case Studies

    ERIC Educational Resources Information Center

    McIntosh, Beth; Dodd, Barbara

    2008-01-01

    Children with unintelligible speech differ in severity, underlying deficit, type of surface error patterns and response to treatment. Detailed treatment case studies, evaluating specific intervention protocols for particular diagnostic groups, can identify best practice for children with speech disorder. Three treatment case studies evaluated the…

  7. Evaluation of Core Vocabulary Intervention for Treatment of Inconsistent Phonological Disorder: Three Treatment Case Studies

    ERIC Educational Resources Information Center

    McIntosh, Beth; Dodd, Barbara

    2009-01-01

    Children with unintelligible speech differ in severity, underlying deficit, type of surface error patterns and response to treatment. Detailed treatment case studies, evaluating specific intervention protocols for particular diagnostic groups, can identify best practice for children with speech disorder. Three treatment case studies evaluated the…

  8. A Unit of Study Approach for Teaching Common Core State Standards for Writing

    ERIC Educational Resources Information Center

    Pytash, Kristine E.; Morgan, Denise N.

    2013-01-01

    In this article, the authors provide an overview of the unit of study framework for teaching writing and explain how it sets the stage for developing "academic momentum" in students (Strahan, 2008, p. 4). To help readers understand the unit of study framework in action, the authors describe how a unit unfolds in one subject area,…

  9. What controls the oxidative ratio of UK peats? A multi-site study of elemental CHNO concentrations in peat cores

    NASA Astrophysics Data System (ADS)

    Clay, Gareth; Worrall, Fred; Masiello, Carrie

    2013-04-01

    The oxidative ratio (OR) is the amount of CO2 sequestered in the terrestrial biosphere for each mol of O2 produced. The OR governs the effectiveness of a terrestrial biome to mitigate the impact of anthropogenic CO2 emissions and it has been used to calculate the balance of terrestrial and oceanic carbon sinks across the globe. However, few studies have investigated the controls of the variability in OR. What factors affect OR - climate? Soil type? Vegetation type? N deposition? Land use? Land use change? Small shifts in OR could have important implications in the global partitioning of CO2 between the atmosphere, biosphere, and oceans. This study looks at peat soils from a series of sites representing a climatic transect across the UK. Duplicate peat cores were taken, along with samples of above-ground vegetation and litter, from sites in northern Scotland (Forsinard), southern Scotland (Auchencorth), northern England (Moor House; Thorne Moor) through the Welsh borders (Whixhall Moss) and Somerset levels (Westhay Moor) to Dartmoor and Bodmin Moor in the south west of England. Sub-samples of the cores were analysed for their CHNO concentrations using a Costech ECS 4010 Elemental combustion system. Using the method of Masiello et al. (2008), OR values could be calculated from these elemental concentrations. Results show that OR values of UK peats varied between 0.82 and 1.27 with a median value of 1.08 which is within the range of world soils. There were significant differences in OR of the peat between sites with the data falling into two broad groupings - Group 1: Forsinard, Auchencorth, Dartmoor and Bodmin Moor; Group 2: Moor House, Thorne Moor, Westhay Moor, Whixhall Moss. Whilst there were significant changes (p < 0.05) in elemental ratios with increasing peat depth (increasing C:N ratio and decreasing O:C ratio) there was no significant difference overall in OR with depth. This paper will explore some of the possible controlling factors on these ratios. Local

  10. Core layering

    NASA Astrophysics Data System (ADS)

    Jacobson, S. A.; Rubie, D. C.; Hernlund, J. W.; Morbidelli, A.

    2015-12-01

    We have created a planetary accretion and differentiation model that self-consistently builds and evolves Earth's core. From this model, we show that the core grows stably stratified as the result of rising metal-silicate equilibration temperatures and pressures, which increases the concentrations of light element impurities into each newer core addition. This stable stratification would naturally resist convection and frustrate the onset of a geodynamo, however, late giant impacts could mechanically mix the distinct accreted core layers creating large homogenous regions. Within these regions, a geodynamo may operate. From this model, we interpret the difference between the planetary magnetic fields of Earth and Venus as a difference in giant impact histories. Our planetary accretion model is a numerical N-body integration of the Grand Tack scenario [1]—the most successful terrestrial planet formation model to date [2,3]. Then, we take the accretion histories of Earth-like and Venus-like planets from this model and post-process the growth of each terrestrial planet according to a well-tested planetary differentiation model [4,5]. This model fits Earth's mantle by modifying the oxygen content of the pre-cursor planetesimals and embryos as well as the conditions of metal-silicate equilibration. Other non-volatile major, minor and trace elements included in the model are assumed to be in CI chondrite proportions. The results from this model across many simulated terrestrial planet growth histories are robust. If the kinetic energy delivered by larger impacts is neglected, the core of each planet grows with a strong stable stratification that would significantly impede convection. However, if giant impact mixing is very efficient or if the impact history delivers large impacts late, than the stable stratification can be removed. [1] Walsh et al. Nature 475 (2011) [2] O'Brien et al. Icarus 223 (2014) [3] Jacobson & Morbidelli PTRSA 372 (2014) [4] Rubie et al. EPSL 301

  11. Palaeoclimatic changes during the Upper Cretaceous of eastern Denmark: a study based on the Stevns-2 chalk core

    NASA Astrophysics Data System (ADS)

    Boussaha, M.; Stemmerik, L.; Thibault, N.

    2013-12-01

    Cretaceous Danish Basin (Surlyk and Lykke-Andersen, 2007). Acknowledgments: Funding for this study was provided by Maersk Oil, the Danish Natural Science Research Foundation and the University of Copenhagen. REFERENCES Stemmerik, L., Surlyk, F., Klitten, K., Rasmussen, S. L., Schovsbo, N., 2006. Shallow core drilling of the Upper Cretaceous Chalk at Stevns Klint, Denmark. GEUS, 2006. Geological Survey of Denmark and Greenland Bulletin 10, 13-16. Surlyk, F., Lykker-Andersen, H., 2007. Contourite drifts, moats and channels in the Upper Cretaceous chalk of the Danish Basin. Sedimentology 54, 405-42. Thibault, N., & Gardin, S., 2006. Maastrichtian calcareous nannofossil biostratigraphy and paleoecology in the Equatorial Atlantic (Demerara Rise, ODP Leg 207 Hole 1258A). Revue de micropaléontologie 49, 199-214. Thibault, N., Schovsbo, N., Harlou, R., Stemmerik, L., Surlyk, F., 2011. An age-calibrated record of upper Campanian - Maastrichtian climate change in the Boreal Realm. AGU Fall meeting 2011, San Francisco, USA, 05-12-11.

  12. Multiple site study of recent atmospheric metal (Pb, Zn and Cu) deposition in the NW Iberian Peninsula using peat cores.

    PubMed

    Olid, Carolina; Garcia-Orellana, Jordi; Martínez-Cortizas, Antonio; Masqué, Pere; Peiteado-Varela, Eva; Sanchez-Cabeza, Joan-Albert

    2010-10-15

    In order to estimate atmospheric metal deposition in Southern Europe since the beginning of the Industrial Period (~1850 AD), concentration profiles of Pb, Zn and Cu were determined in four (210)Pb-dated peat cores from ombrotrophic bogs in Serra do Xistral (Galicia, NW Iberian Peninsula). Maximum metal concentrations varied by a factor of 1.8 for Pb and Zn (70 to 128μgg(-1) and 128 to 231μgg(-1), respectively) and 3.5 for Cu (11 to 37μgg(-1)). The cumulative metal inventories of each core varied by a factor of 3 for all analysed metals (132 to 329μgcm(-2) for Pb, 198 to 625μgcm(-2) for Zn and 22 to 69μgcm(-2) for Cu), suggesting differences in net accumulation rates among peatlands. Although results suggest that mean deposition rates vary within the studied area, the enhanced (210)Pb accumulation and the interpretation of the inventory ratios ((210)Pb/Pb, Zn/Pb and Cu/Pb) in two bogs indicated that either a record perturbation or post-depositional redistribution effects must be considered. After correction, Pb, Zn and Cu profiles showed increasing concentrations and atmospheric fluxes since the mid-XX(th) century to maximum values in the second half of the XX(th) century. For Pb, maximum fluxes were observed in 1955-1962 and ranged from 16 to 22mgm(-2)yr(-1) (mean of 18±1mgm(-2)yr(-1)), two orders of magnitude higher than in the pre-industrial period. Peaks in Pb fluxes in Serra do Xistral before the period of maximum consumption of leaded petrol in Europe (1970s-1980s) suggest the dominance of local pollutant sources in the area (i.e. coal mining and burning). More recent peaks were observed for Zn and Cu, with fluxes ranging from 32 to 52mgm(-2)yr(-1) in 1989-1996, and from 4 to 9mgm(-2)yr(-1) in 1994-2001, respectively. Our results underline the importance of multi-core studies to assess both the integrity and reliability of peat records, and the degree of homogeneity in bog accumulation. We show the usefulness of using the excess (210)Pb inventory to

  13. Prospective Study for Comparison of Endoscopic Ultrasound-Guided Tissue Acquisition Using 25- and 22-Gauge Core Biopsy Needles in Solid Pancreatic Masses

    PubMed Central

    Lee, Sang Hoon; Lee, Hee Seung; Lee, Hyun Jik; Park, Jeong Yup; Park, Seung Woo; Song, Si Young; Kim, Hoguen; Chung, Jae Bock; Bang, Seungmin

    2016-01-01

    Background and Aims Although thicker needles theoretically allow more tissue to be collected, their decreased flexibility can cause mechanical damage to the endoscope, technical failure, and sample blood contamination. The effects of needle gauge on diagnostic outcomes of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) of pancreatic mass lesions remain unknown. This study compared procurement rates of histologic cores obtained from EUS-FNB of pancreatic masses using 25- and 22-gauge core biopsy needles. Patients and Methods From March 2014 to July 2014, 66 patients with solid pancreatic mass underwent EUS-FNB with both 25- and 22-gauge core biopsy needles. Among them, 10 patients were excluded and thus 56 patients were eligible for the analyses. Needle sequences were randomly assigned, and two passes were made with each needle, consisting of 10 uniform to-and-fro movements on each pass with 10 mL syringe suction. A pathologist blinded to needle sequence evaluated specimens for the presence of histologic core. Results The mean patient age was 65.8 ± 9.5 years (range, 44–89 years); 35 patients (62.5%) were men. The mean pancreatic mass size was 35.3 ± 17.1 mm (range 14–122.3 mm). Twenty-eight patients (50%) had tumors at the pancreas head or uncinate process. There were no significant differences in procurement rates of histologic cores between 25-gauge (49/56, 87.5%) and 22-gauge (46/56, 82.1%, P = 0.581) needles or diagnostic accuracy using only histologic cores (98% and 95%). There were no technical failures or procedure-related adverse events. Conclusions The 25-gauge core biopsy needle could offer acceptable and comparable outcomes regarding diagnostic performance including histologic core procurement rates compared to the 22-gauge core biopsy needle, although the differences were not statistically significant. Trial Registration ClinicalTrials.gov NCT01795066 PMID:27149404

  14. An In Vitro Study on the Effects of Post-Core Design and Ferrule on the Fracture Resistance of Endodontically Treated Maxillary Central Incisors

    PubMed Central

    Sreedevi, S; Sanjeev, R; Raghavan, Rekha; Abraham, Anna; Rajamani, T; Govind, Girish Kumar

    2015-01-01

    Background: Endodontically treated teeth have significantly different physical and mechanical properties compared to vital teeth and are more prone to fracture. The study aims to compare the fracture resistance of endodontically treated teeth with and without post reinforcement, custom cast post-core and prefabricated post with glass ionomer core and to evaluate the ferrule effect on endodontically treated teeth restored with custom cast post-core. Materials and Methods: A total of 40 human maxillary central incisors with similar dimensions devoid of any root caries, restorations, previous endodontic treatment or cracks were selected from a collection of stored extracted teeth. An initial silicone index of each tooth was made. They were treated endodontically and divided into four groups of ten specimens each. Their apical seal was maintained with 4 mm of gutta-percha. Root canal preparation was done and then post core fabrication was done. The prepared specimens were subjected to load testing using a computer coordinated UTM. The fracture load results were then statistically analyzed. One-way ANOVA was followed by paired t-test. Results: 1. Reinforcement of endodontically treated maxillary central incisors with post and core, improved their fracture resistance to be at par with that of endodontically treated maxillary central incisor, with natural crown. 2. The fracture resistance of endodontically treated maxillary central incisors is significantly increased when restored with custom cast post-core and 2 mm ferrule. Conclusion: With 2 mm ferrule, teeth restored with custom cast post-core had a significantly higher fracture resistance than teeth restored with custom cast post-core or prefabricated post and glass ionomer core without ferrule. PMID:26464537

  15. Synthesis and optical study of green light emitting polymer coated CdSe/ZnSe core/shell nanocrystals

    SciTech Connect

    Tripathi, S.K.; Sharma, Mamta

    2013-05-15

    Highlights: ► Synthesis of Polymer coated core CdSe and CdSe/ZnSe core/shell NCs. ► From TEM image, the spherical nature of CdSe and CdSe/ZnSe is obtained. ► Exhibiting green band photoemission peak at 541 nm and 549 nm for CdSe core and CdSe/ZnSe core/shell NCs. ► The shell thickness has been calculated by using superposition of quantum confinement energy model. - Abstract: CdSe/ZnSe Core/Shell NCs dispersed in PVA are synthesized by chemical method at room temperature. This is characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV/Vis spectra and photoluminescence spectroscopy (PL). TEM image shows the spherical nature of CdSe/ZnSe core/shell NCs. The red shift of absorption and emission peak of CdSe/ZnSe core/shell NCs as compared to CdSe core confirmed the formation of core/shell. The superposition of quantum confinement energy model is used for calculation of thickness of ZnSe shell.

  16. Scoping studies of the alternative options for defueling, packaging, shipping, and disposing of the TMI-2 spent fuel core

    SciTech Connect

    Anderson, Robert T.

    1980-09-01

    A portion of this fuel will be shipped to nuclear facilities to perform detailed physical examinations. Removal of this fuel from the TMI-2 core is also a significant step in the eventual cleanup of this facility. The report presents a scoping study of the technical operations required for defueling and canning. The TMI fuel when canned could be stored in the spent fuel storage pool. After a period of on-site storage, it is expected that the bulk of the fuel will be shipped off-site for either storage or reprocessing. Evaluation is made of the technical, economic, and institutional factors associated with alternate approaches to disposition of this fuel. Recommendations are presented concerning future generic development tasks needed for the defueling, packaging, on-site shipping of this fuel.

  17. Core-shell magnetic nanoparticles: a comparative study based on silica and polydopamine coating for magnetic bio-separation platforms.

    PubMed

    Sahin, Ferat; Turan, Eylem; Tumturk, Hayrettin; Demirel, Gokhan

    2012-12-01

    Core-shell magnetic nanoparticles (MNPs) offer tremendous opportunities in a large range of applications in biomedicine due to their superior magnetic properties, biocompatibility and suitability for modification. In most cases, these characteristic features are determined by their shell chemistry and morphology. Herein, we demonstrate a comparative study of silica and polydopamine (PDOP) coating onto MNP surfaces based on synthesis, characterization and usage in a bio-separation platform. It was found that monodispersed MNPs may be easily obtained on silica coating of varying shell thickness, whereas a continuous PDOP layer observed around the MNPs prevents the formation of the dispersed form. On the other hand, PDOP coated MNPs exhibited better superparamagnetic behavior and biological modification ability compared to the silica coated form. PMID:23050265

  18. Strain localization in granodiorite mylonites: a microstructural and electron backscatter diffraction (EBSD) study of the South Mountains core complex, Arizona

    NASA Astrophysics Data System (ADS)

    Greenberg, R. M.; Miranda, E.

    2009-12-01

    The quantification of strain localization in detachment fault shear zones is essential to the study of continental core complex development and permits insight into continental crust rheology during extension. We present a microstructural and EBSD study of naturally deformed shear zone rocks from the footwall of the South Mountains, Arizona, core complex to interpret the deformation mechanisms that lead to strain localization along the detachment fault. The footwall of the South Mountains core complex is dominated by a Miocene composite pluton that exhibits Miocene extensional mylonitic fabrics associated with the structural development of the core complex. The composite pluton is composed of granodiorite, granite, and quartzolite, but the granodiorite is the most voluminous of the intrusive units. The detachment fault shear zone is developed within the granodiorite and quartzolite intrusive units. We conducted a microstructural and EBSD study of the Tertiary South Mountains granodiorite and quartzolite mylonites to determine the deformation mechanisms that promote strain localization. We hypothesize that the strength of quartz strongly influences strain localization in the naturally deformed granodiorite mylonites and quartzolite mylonites. The five samples were collected on an up-structure traverse through the ~60 meter thick mylonitic shear zone towards the interpreted detachment fault surface. Microstructural observation of quartz grains reveals the presence of elongate ‘ribbon grains’ with subgrain development along the rims of these grains, and irregular and sinuous sutured grain boundaries. We interpret these microstructures as evidence of Regimes 2 and 3 dynamic recrystallization. In contrast, the plagioclase feldspar and potassium feldspar crystals are microfractured with limited development of bulging grain boundaries on the rims of the feldspar grains, which we interpret as evidence of Regime 1 dynamic recrystallization. Up the traverse in the

  19. Multiple Core Galaxies

    NASA Technical Reports Server (NTRS)

    Miller, R.H.; Morrison, David (Technical Monitor)

    1994-01-01

    Nuclei of galaxies often show complicated density structures and perplexing kinematic signatures. In the past we have reported numerical experiments indicating a natural tendency for galaxies to show nuclei offset with respect to nearby isophotes and for the nucleus to have a radial velocity different from the galaxy's systemic velocity. Other experiments show normal mode oscillations in galaxies with large amplitudes. These oscillations do not damp appreciably over a Hubble time. The common thread running through all these is that galaxies often show evidence of ringing, bouncing, or sloshing around in unexpected ways, even though they have not been disturbed by any external event. Recent observational evidence shows yet another phenomenon indicating the dynamical complexity of central regions of galaxies: multiple cores (M31, Markarian 315 and 463 for example). These systems can hardly be static. We noted long-lived multiple core systems in galaxies in numerical experiments some years ago, and we have more recently followed up with a series of experiments on multiple core galaxies, starting with two cores. The relevant parameters are the energy in the orbiting clumps, their relative.masses, the (local) strength of the potential well representing the parent galaxy, and the number of cores. We have studied the dependence of the merger rates and the nature of the final merger product on these parameters. Individual cores survive much longer in stronger background potentials. Cores can survive for a substantial fraction of a Hubble time if they travel on reasonable orbits.

  20. Probing the Core: What Knowledge Is Most Useful to Management Majors: An Exploratory Study.

    ERIC Educational Resources Information Center

    Rosenbloom, Al

    This study investigated whether and to what degree management majors at one small, liberal arts institution actually "used" course knowledge on their job. Phase 1 surveyed all management majors graduating from the institution between 1988-1992, asking graduates to estimate the percentage of useful knowledge gained from each component of their…

  1. The Special Education Core Curriculum Manual: Competency Level -- Communication Skills, Mathematics, Life Skills, and Study Skills.

    ERIC Educational Resources Information Center

    Margolis, Leonard; And Others

    The manual is intended to provide basic objectives and teaching strategies for teachers of handicapped children at the upper elementary and secondary level in the areas of communication, mathematics, life skills, and study skills. Each subject area is divided into sub-sections under which learning objectives and associated teaching activities are…

  2. THE INNER CORE--NORTH, A STUDY OF MILWAUKEE'S NEGRO COMMUNITY.

    ERIC Educational Resources Information Center

    O'REILLY, CHARLES T.

    A STUDY OF THE NEGRO COMMUNITY OF MILWAUKEE PRESENTS DATA ON RESIDENCE, EDUCATION, HOUSING, OCCUPATIONS AND EMPLOYMENT, THE EMERGING MIDDLE CLASS, AND PROGNOSTICATIONS ABOUT THE FUTURE GROWTH OF NEGRO POPULATION. MOST OF THE AVAILABLE INFORMATION WAS DERIVED FROM THE 1960 CENSUS, WITH COMPARISONS CONTINUALLY MADE TO THE 1950 CENSUS FIGURES. AN…

  3. Putting History at the Core: History and Literature in Environmental Studies

    ERIC Educational Resources Information Center

    Morse, Kathryn

    2003-01-01

    When environmental studies programs broaden their curricular offerings into the humanities, their first stop is often environmental literature, particularly classics such as Henry David Thoreau's "Walden," Aldo Leopold's "A Sand County Almanac," and Rachel Carson's "Silent Spring." Environmental literature courses consider many of the works of…

  4. Student Presentations of Case Studies to Illustrate Core Concepts in Soil Biogeochemistry

    ERIC Educational Resources Information Center

    Duckworth, Owen W.; Harrington, James M.

    2012-01-01

    Soil biogeochemistry, a discipline that explores the chemical speciation and transformations of elements in soils and the relationships between soils and global biogeochemical cycles, is becoming a popular course offering because it unites themes from a number of other courses. In this article, we present a set of case studies that have been used…

  5. Developing a Vision for the Common Core Classroom: What Does Elementary Social Studies Look Like?

    ERIC Educational Resources Information Center

    Britt, Judy; Howe, Mandi

    2014-01-01

    In each edition of their book "Doing History: Investigating with Children in Elementary and Middle Schools", Levstik and Barton (2011) encourage us to take a mental journey to imagine classrooms where students regularly "do history" (xi). The social studies experiences that many educators envision for elementary classrooms…

  6. Clearing the Highest Hurdle: Human-Based Case Studies Broaden Students' Knowledge of Core Evolutionary Concepts

    ERIC Educational Resources Information Center

    Werth, Alexander J.

    2009-01-01

    An anonymous survey instrument was used for a ten year study to gauge college student attitudes toward evolution. Results indicate that students are most likely to accept evolution as a historical process for change in physical features of non-human organisms. They are less likely to accept evolution as an ongoing process that shapes all traits…

  7. The Development of Core Cognitive Skills in Autism: A 3-Year Prospective Study

    ERIC Educational Resources Information Center

    Pellicano, Elizabeth

    2010-01-01

    This longitudinal study tested the veracity of one candidate multiple-deficits account of autism by assessing 37 children with autism (M age = 67.9 months) and 31 typical children (M age = 65.2 months) on tasks tapping components of theory of mind (ToM), executive function (EF), and central coherence (CC) at intake and again 3 years later. As a…

  8. Re-Establishing Social Studies as a Core Subject: An Interview with Susan Griffin

    ERIC Educational Resources Information Center

    Griffin, Susan

    2014-01-01

    NCSS Executive Director Susan Griffin was chair of the Task Force of Professional Organizations that worked with the Social Studies Assessment, Curriculum, and Instruction Collaborative (SSACI) of the Council of Chief State School Officers to initiate and guide the development of the "College, Career and Civic Life (C3) Framework for Social…

  9. A Study of the Access to the Scholarly Record From a Hospital Health Science Core Collection.

    ERIC Educational Resources Information Center

    Williams, James F., II; Pings, Vern M.

    This study is an effort to determine possible service performance levels in hospital libraries, based on access to the scholarly record of medicine through selected lists of clinical journals and indexing and abstracting journals. Specific emphasis is placed on (1) the citation verification through the use of the index and abstract journals, (2)…

  10. Improving Middle School Parental Engagement in Transition to Common Core State Standards: An Action Research Study

    ERIC Educational Resources Information Center

    Harla, Donna K.

    2014-01-01

    Parental involvement in schools is an important potential contributor to improving American education and making the U.S. more globally competitive. This qualitative and quantitative mixed-methodology action research study probed the viability of engaging parents around issues of educational improvement by inviting them to participate in training…

  11. Three axis fluxgate magnetometer with ring core development for studies and monitoring the South Atlantic Magnetic Anomaly - SAMA

    NASA Astrophysics Data System (ADS)

    Espindola Antunes, Cassio; Schuch, Nelson Jorge; de Siqueira, Josemar; Santos Silveira, Lucas; Babulal Trivedi, Nalin

    The Earth Magnetic Field variations are studied in different time scales classified as secular to diurnal variations and also micropulsations that have period smaller than 1000 seconds. The data acquisition for investigation of this phenomena can provide important information about the Magnetosphere, the Earth/Sun interaction, as well as events occurring in the Ionosphere which can, for instance, generate disturbances in telecommunications, small satellites or even in the space weather. In the area where there is observed the smallest intensity of the Earth's magnetic field on the Global' surface, the South Atlantic Magnetic Anomaly - SAMA, there frequently occur charged particle precipitations during magnetic storms. We have developed a three axis ring core fluxgate magnetometer at the Southern Regional Space Research Center - CRS/CIE/INPE-MCT in the south of Brazil to study the behavior and the geomagnetic process in the SAMA‘s proximities. The fluxgate magnetometer has its operation based on the iron magnetic properties of the high permeability ring-core. Varying the magnetic permeability of the nucleus through a high frequency excitation signal it is possible to obtain a response changing the magnetic saturation around the nucleus as in the (BxH) Hystereses curve. The sensor coil detects a signal with high harmonic content that has linear relation with the Earth's Magnetic Field variations in the observed local. This paper has the intention to show the way used to implement the sensor, the electric circuit and specially the preliminary data and conclusions about experiments performed at the Southern Space Observatory SSO/CRS/INPE - MCT which is located near the center of the SAMA in Brazil. This project also has the objective to develop this kind of low cost fluxgate magnetometers to install it at different points along the SAMA edge.

  12. Micro coring apparatus

    NASA Technical Reports Server (NTRS)

    Collins, David; Brooks, Marshall; Chen, Paul; Dwelle, Paul; Fischer, Ben

    1989-01-01

    A micro-coring apparatus for lunar exploration applications, that is compatible with the other components of the Walking Mobile Platform, was designed. The primary purpose of core sampling is to gain an understanding of the geological composition and properties of the prescribed environment. This procedure has been used extensively for Earth studies and in limited applications during lunar explorations. The corer is described and analyzed for effectiveness.

  13. Anoxic and oxic removal of humic acids with Fe@Fe2O3 core-shell nanowires: a comparative study.

    PubMed

    Wu, Hao; Ai, Zhihui; Zhang, Lizhi

    2014-04-01

    In this study we comparatively investigate the removal of humic acids with Fe@Fe2O3 core-shell nanowires under anoxic and oxic conditions. The products of humic acids after reacting with Fe@Fe2O3 core-shell nanowires under anoxic and oxic conditions were carefully examined with three-dimensional excitation emission matrix fluorescence spectroscopy and gas chromatography mass spectrometry. It was found that humic acids were removed by Fe@Fe2O3 core-shell nanowires via adsorption under anoxic condition. Langmuir adsorption isotherm was applicable to describe the adsorption processes. Kinetics of humic acids adsorption onto Fe@Fe2O3 core-shell nanowires was found to follow pseudo-second-order rate equation. By contrast, the oxic removal of humic acids with Fe@Fe2O3 core-shell nanowires involved adsorption and subsequent oxidation of humic acids because Fe@Fe2O3 core-shell nanowires could activate molecular oxygen to produce reactive oxygen species to oxidize humic acids. This subsequent oxidation of humic acids could improve the oxic removal rate to 2.5 times that of anoxic removal, accompanying with about 8.4% of mineralization. This study provides a new method for humic acids removal and also sheds light on the effects of humic acids on the pollutant removal by nano zero-valent iron. PMID:24463174

  14. Anoxic and oxic removal of humic acids with Fe@Fe2O3 core-shell nanowires: a comparative study.

    PubMed

    Wu, Hao; Ai, Zhihui; Zhang, Lizhi

    2014-04-01

    In this study we comparatively investigate the removal of humic acids with Fe@Fe2O3 core-shell nanowires under anoxic and oxic conditions. The products of humic acids after reacting with Fe@Fe2O3 core-shell nanowires under anoxic and oxic conditions were carefully examined with three-dimensional excitation emission matrix fluorescence spectroscopy and gas chromatography mass spectrometry. It was found that humic acids were removed by Fe@Fe2O3 core-shell nanowires via adsorption under anoxic condition. Langmuir adsorption isotherm was applicable to describe the adsorption processes. Kinetics of humic acids adsorption onto Fe@Fe2O3 core-shell nanowires was found to follow pseudo-second-order rate equation. By contrast, the oxic removal of humic acids with Fe@Fe2O3 core-shell nanowires involved adsorption and subsequent oxidation of humic acids because Fe@Fe2O3 core-shell nanowires could activate molecular oxygen to produce reactive oxygen species to oxidize humic acids. This subsequent oxidation of humic acids could improve the oxic removal rate to 2.5 times that of anoxic removal, accompanying with about 8.4% of mineralization. This study provides a new method for humic acids removal and also sheds light on the effects of humic acids on the pollutant removal by nano zero-valent iron.

  15. A study of the science of taste: on the origins and influence of the core ideas.

    PubMed

    Erickson, Robert P

    2008-02-01

    Our understanding of the sense of taste is largely based on research designed and interpreted in terms of the traditional four "basic" tastes: sweet, sour, salty, and bitter, and now a few more. This concept of basic tastes has no rational definition to test, and thus it has not been tested. As a demonstration, a preliminary attempt to test one common but arbitrary psychophysical definition of basic tastes is included in this article; that the basic tastes are unique in being able to account for other tastes. This definition was falsified in that other stimuli do about as well as the basic words and stimuli. To the extent that this finding might show analogies with other studies of receptor, neural, and psychophysical phenomena, the validity of the century-long literature of the science of taste based on a few "basics" is called into question. The possible origins, meaning, and influence of this concept are discussed. Tests of the model with control studies are suggested in all areas of taste related to basic tastes. As a stronger alternative to the basic tradition, the advantages of the across-fiber pattern model are discussed; it is based on a rational data-based hypothesis, and has survived attempts at falsification. Such "population coding" has found broad acceptance in many neural systems.

  16. Revisit of polystyrene-modified fullerene core stars: A computational study.

    PubMed

    Zhou, Jia

    2015-09-01

    Density functional theory (DFT) calculations have been used to clarify the number of poly(styryl) lithium anions that are grafted onto C60 fullerene. The computational results suggest that 6-arm-grafted C60 fullerene is the most thermodynamically favorable, and the grafted C60 fullerene with arms more than 6 is only achievable under certain circumstances. This observation is consistent with the previous experiments [Macromolecules 2013; 46:7451-57.]. Both electronic effect and steric effect have been thoroughly examined and they are found to play different roles in the arm-grafted C60 fullerene. The current study will pave a way for the future architecture of polymers on C60 fullerene and the like.

  17. Gyrokinetic studies of core turbulence features in ASDEX Upgrade H-mode plasmas

    SciTech Connect

    Navarro, A. Bañón Told, D.; Happel, T.; Görler, T.; Abiteboul, J.; Bustos, A.; Doerk, H.; Jenko, F.

    2015-04-15

    Gyrokinetic validation studies are crucial for developing confidence in the model incorporated in numerical simulations and thus improving their predictive capabilities. As one step in this direction, we simulate an ASDEX Upgrade discharge with the GENE code, and analyze various fluctuating quantities and compare them to experimental measurements. The approach taken is the following. First, linear simulations are performed in order to determine the turbulence regime. Second, the heat fluxes in nonlinear simulations are matched to experimental fluxes by varying the logarithmic ion temperature gradient within the expected experimental error bars. Finally, the dependence of various quantities with respect to the ion temperature gradient is analyzed in detail. It is found that density and temperature fluctuations can vary significantly with small changes in this parameter, thus making comparisons with experiments very sensitive to uncertainties in the experimental profiles. However, cross-phases are more robust, indicating that they are better observables for comparisons between gyrokinetic simulations and experimental measurements.

  18. Developing the new Columbia core curriculum: a case study in managing radical curriculum change.

    PubMed

    Galea, Sandro; Fried, Linda P; Walker, Julia R; Rudenstine, Sasha; Glover, Jim W; Begg, Melissa D

    2015-03-01

    Curricular change is essential for maintaining vibrant, timely, and relevant educational programming. However, major renewal of a long-standing curriculum at an established university presents many challenges for leaders, faculty, staff, and students. We present a case study of a dramatic curriculum renewal of one of the nation's largest Master of Public Health degree programs: Columbia University's Mailman School of Public Health. We discuss context, motivation for change, the administrative structure established to support the process, data sources to inform our steps, the project timeline, methods for engaging the school community, and the extensive planning that was devoted to evaluation and communication efforts. We highlight key features that we believe are essential for successful curricular change. PMID:25706010

  19. Dynamic model verification studies for the thermal response of the Fort St. Vrain HTGR Core

    SciTech Connect

    Ball, S J

    1980-01-01

    The safety research program for high-temperature gas-cooled reactors at ORNL is directed primarily at addressing licensing questions on the Fort St. Vrain reactor near Denver, CO. An important part of the program is to make use of experimental data from the reactor to at least partially verify the dynamic simulations that are used to predict the effects of postulated accident sequences. Comparisons were made of predictions with data from four different reactor scram (trip) events from operating power levels between 30 and 50%. An optimization program was used to rationalize the differences between predictions and measurements, and, in general, excellent agreement can be obtained by adjustment of models and parameters within their uncertainty ranges. Although the optimized models are not necessarily unique, results of the study have identified areas in which some of the models were deficient.

  20. Study of coordination environments around Pd and Pt in a Pd-core Pt-shell nanoparticle during heating

    NASA Astrophysics Data System (ADS)

    Nishimura, Y. F.; Hamaguchi, T.; Yamaguchi, S.; Takagi, H.; Dohmae, K.; Nonaka, T.; Nagai, Y.

    2016-05-01

    Local coordination environments around Pd and Pt in a Pd-core Pt-shell nanoparticle (NP) at temperatures ranging from 473 to 873 K was evaluated by utilizing in situ XAFS measurement technique to investigate the temperature range in which a core-shell structure is preserved. The core-shell structure was considered to be kept up to 673 K and start to change at about 773 K. Heating to 873 K accelerated atomic mixing in the core-shell NPs. Catalytic properties of the present Pd-core Pt-shell NP are available in the stoichiometric C3H6-O2 atmosphere at temperatures less than 773 K at most.

  1. Cannibalism Affects Core Metabolic Processes in Helicoverpa armigera Larvae—A 2D NMR Metabolomics Study

    PubMed Central

    Vergara, Fredd; Shino, Amiu; Kikuchi, Jun

    2016-01-01

    Cannibalism is known in many insect species, yet its impact on insect metabolism has not been investigated in detail. This study assessed the effects of cannibalism on the metabolism of fourth-instar larvae of the non-predatory insect Helicoverpa armigera (Lepidotera: Noctuidea). Two groups of larvae were analyzed: one group fed with fourth-instar larvae of H. armigera (cannibal), the other group fed with an artificial plant diet. Water-soluble small organic compounds present in the larvae were analyzed using two-dimensional nuclear magnetic resonance (NMR) and principal component analysis (PCA). Cannibalism negatively affected larval growth. PCA of NMR spectra showed that the metabolic profiles of cannibal and herbivore larvae were statistically different with monomeric sugars, fatty acid- and amino acid-related metabolites as the most variable compounds. Quantitation of 1H-13C HSQC (Heteronuclear Single Quantum Coherence) signals revealed that the concentrations of glucose, glucono-1,5-lactone, glycerol phosphate, glutamine, glycine, leucine, isoleucine, lysine, ornithine, proline, threonine and valine were higher in the herbivore larvae. PMID:27598144

  2. Cannibalism Affects Core Metabolic Processes in Helicoverpa armigera Larvae-A 2D NMR Metabolomics Study.

    PubMed

    Vergara, Fredd; Shino, Amiu; Kikuchi, Jun

    2016-01-01

    Cannibalism is known in many insect species, yet its impact on insect metabolism has not been investigated in detail. This study assessed the effects of cannibalism on the metabolism of fourth-instar larvae of the non-predatory insect Helicoverpa armigera (Lepidotera: Noctuidea). Two groups of larvae were analyzed: one group fed with fourth-instar larvae of H. armigera (cannibal), the other group fed with an artificial plant diet. Water-soluble small organic compounds present in the larvae were analyzed using two-dimensional nuclear magnetic resonance (NMR) and principal component analysis (PCA). Cannibalism negatively affected larval growth. PCA of NMR spectra showed that the metabolic profiles of cannibal and herbivore larvae were statistically different with monomeric sugars, fatty acid- and amino acid-related metabolites as the most variable compounds. Quantitation of ¹H-(13)C HSQC (Heteronuclear Single Quantum Coherence) signals revealed that the concentrations of glucose, glucono-1,5-lactone, glycerol phosphate, glutamine, glycine, leucine, isoleucine, lysine, ornithine, proline, threonine and valine were higher in the herbivore larvae. PMID:27598144

  3. Core-core and core-valence correlation

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1988-01-01

    The effect of 1s core correlation on properties and energy separations are analyzed using full configuration-interaction (FCI) calculations. The Be1S - 1P, the C 3P - 5S,m and CH(+) 1Sigma(+) - 1Pi separations, and CH(+) spectroscopic constants, dipole moment, and 1Sigma(+) - 1Pi transition dipole moment have been studied. The results of the FCI calculations are compared to those obtained using approximate methods.

  4. Core-level photoabsorption study of defects and metastable bonding configurations in boron nitride

    SciTech Connect

    Jimenez, I.; Jankowski, A.F.; Terminello, L.J.

    1997-04-01

    Boron nitride is an interesting material for technological applications and for fundamental solid state physics investigations. It is a compound isoelectronic with carbon and, like carbon can possess sp{sup 2} and sp{sup 3} bonded phases resembling graphite and diamond. BN crystallizes in the sp{sup 2}-bonded hexagonal (h-BN), rhombohedral (r-BN) and turbostratic phases, and in the sp{sup 3}-bonded cubic (c-BN) and wurtzite (w-BN) phases. A new family of materials is obtained when replacing C-C pairs in graphite with isoelectronic B-N pairs, resulting in C{sub 2}BN compounds. Regarding other boron compounds, BN is exceptional in the sense that it has standard two-center bonds with conventional coordination numbers, while other boron compounds (e.g. B{sub 4}C) are based on the boron icosahedron unit with three-center bonds and high coordination numbers. The existence of several allotropic forms and fullerene-like structures for BN suggests a rich variety of local bonding and poses the questions of how this affects the local electronic structure and how the material accommodates the stress induced in the transition regions between different phases. One would expect point defects to play a crucial role in stress accommodation, but these must also have a strong influence in the electronic structure, since the B-N bond is polar and a point defect will thus be a charged structure. The study of point defects in relationship to the electronic structure is of fundamental interest in these materials. Recently, the authors have shown that Near-Edge X-ray Absorption Fine Structure (NEXAFS) is sensitive to point defects in h-BN, and to the formation of metastable phases even in amorphous materials. This is significant since other phase identification techniques like vibrational spectroscopies or x-ray diffraction yield ambiguous results for nanocrystalline and amorphous samples. Serendipitously, NEXAFS also combines chemical selectivity with point defect sensitivity.

  5. Support for the Core Research Activities and Studies of the Computer Science and Telecommunications Board (CSTB)

    SciTech Connect

    Jon Eisenberg, Director, CSTB

    2008-05-13

    The Computer Science and Telecommunications Board of the National Research Council considers technical and policy issues pertaining to computer science (CS), telecommunications, and information technology (IT). The functions of the board include: (1) monitoring and promoting the health of the CS, IT, and telecommunications fields, including attention as appropriate to issues of human resources and funding levels and program structures for research; (2) initiating studies involving CS, IT, and telecommunications as critical resources and sources of national economic strength; (3) responding to requests from the government, non-profit organizations, and private industry for expert advice on CS, IT, and telecommunications issues; and to requests from the government for expert advice on computer and telecommunications systems planning, utilization, and modernization; (4) fostering interaction among CS, IT, and telecommunications researchers and practitioners, and with other disciplines; and providing a base of expertise in the National Research Council in the areas of CS, IT, and telecommunications. This award has supported the overall operation of CSTB. Reports resulting from the Board's efforts have been widely disseminated in both electronic and print form, and all CSTB reports are available at its World Wide Web home page at cstb.org. The following reports, resulting from projects that were separately funded by a wide array of sponsors, were completed and released during the award period: 2007: * Summary of a Workshop on Software-Intensive Systems and Uncertainty at Scale * Social Security Administration Electronic Service Provision: A Strategic Assessment * Toward a Safer and More Secure Cyberspace * Software for Dependable Systems: Sufficient Evidence? * Engaging Privacy and Information Technology in a Digital Age * Improving Disaster Management: The Role of IT in Mitigation, Preparedness, Response, and Recovery 2006: * Renewing U.S. Telecommunications Research

  6. Validation of the Comprehensive ICF Core Set for Stroke by exploring the patient's perspective on functioning in everyday life: a qualitative study.

    PubMed

    Paanalahti, Markku; Alt Murphy, Margit; Lundgren-Nilsson, Åsa; Sunnerhagen, Katharina S

    2014-12-01

    International Classification of Functioning, Disability and Health (ICF) core sets are short procedures to record and provide information on health. However, further validation is needed. The aim of this study was to validate the Comprehensive ICF Core Set for stroke by exploring the patient's living at home and receiving outpatient rehabilitation perspective on functioning in everyday life. Qualitative interviews of 22 patients with previous stroke in Finland were analyzed using the content analysis method: functional concepts that described the participants' perspective on functioning in everyday life were extracted from the interview transcripts and linked to ICF categories using ICF linking rules. Extracted functional concepts from 372 meaning units were linked to 115 of the 166 categories included in the Comprehensive ICF Core Set for stroke and to six additional ICF categories. Thirty-eight concepts could not be linked to the ICF categories. Sixty-eight percent of the second-level ICF categories in the Comprehensive ICF Core Set for stroke were validated. In total, 28 of 36 categories added to the Comprehensive ICF Core Set for stroke from the Core Sets for patients with neurological conditions in the acute and early postacute phases were not confirmed in this sample of individuals with stroke living in their homes.

  7. Core Decompression and Autologous Bone Marrow Concentrate for Treatment of Femoral Head Osteonecrosis: A Randomized Prospective Study

    PubMed Central

    Pepke, Wojciech; Kasten, Philip; Beckmann, Nicholas A.; Janicki, Patricia; Egermann, Marcus

    2016-01-01

    The aim of this study was to investigate the safety of injection of bone marrow aspirate concentrate during core decompression and to study its clinical (visual analogue scale; Harris-Hip-score) and radiological outcomes (magnetic resonance imaging). In this prospective and randomized clinical trial we evaluated 24 consecutive patients with non-traumatic femoral head necrosis (FHN) during a period of two years after intervention. In vitro analysis of mesenchymal stem cells was performed by evaluating the fibroblast colony forming units (CFU-Fs). Postoperatively, significant decrease in pain associated with a functional benefit lasting was observed. However, there was no difference in the clinical outcome between the two study groups. Over the period of two years there was no significant difference between the head survival rate between both groups. In contrast to that, we could not perceive any significant change in the volume of FHN in both treatment groups related to the longitudinal course after treating. The number of CFU showed a significant increase after centrifugation. This trial could not detect a benefit from the additional injection of bone marrow concentrate with regard to bone regeneration and clinical outcome in the short term. PMID:27114808

  8. Ten-Year Results From the Natrelle 410 Anatomical Form-Stable Silicone Breast Implant Core Study

    PubMed Central

    Maxwell, G. Patrick; Van Natta, Bruce W.; Bengtson, Bradley P.; Murphy, Diane K.

    2015-01-01

    Background Silicone breast implants have long been used for breast augmentation and reconstruction. During this time, these medical devices have gone through a number of modifications to improve their safety, quality, and clinical outcome performance. Objectives The authors conducted a 10-year study to determine the safety and effectiveness of Natrelle 410 silicone breast implants. Methods This prospective, multicenter study enrolled 941 subjects who were undergoing either augmentation, augmentation revision, reconstruction, or reconstruction revision. Data on complications, reoperations, explantations, and subject satisfaction were collected at annual clinic visits, and one-third of subjects underwent biennial magnetic resonance imaging (MRI) to screen for implant rupture. The authors used the Kaplan-Meier estimator to calculate risk rates for local complications, reoperations, and explantations. Results Capsular contracture rates increased approximately 1% per year from the previously reported 6-year rates. The rates were significantly lower than those from the Natrelle round gel core study. The overall rate of confirmed ruptured implants in subjects who underwent MRI was 5.7%. Eleven late seromas were reported. The most common reason for explantation was a subject requesting a size or style change. Satisfaction rates remained high through 10 years, with most subjects saying they were somewhat or definitely satisfied with their implants. Conclusions This 10-year prospective trial demonstrated the long-term safety and effectiveness of Natrelle 410 anatomical form-stable implants. The complication rates were low and the satisfaction rates were high. Level of Evidence: 1 Therapeutic PMID:25717116

  9. Different timing features in brain processing of core and moral disgust pictures: an event-related potentials study.

    PubMed

    Zhang, Xiangyi; Guo, Qi; Zhang, Youxue; Lou, Liandi; Ding, Daoqun

    2015-01-01

    Disgust, an emotion motivating withdrawal from offensive stimuli, protects us from the risk of biological pathogens and sociomoral violations. Homogeneity of its two types, namely, core and moral disgust has been under intensive debate. To examine the dynamic relationship between them, we recorded event-related potentials (ERPs) for core disgust, moral disgust and neutral pictures while participants performed a modified oddball task. ERP analysis revealed that N1 and P2 amplitudes were largest for the core disgust pictures, indicating automatic processing of the core disgust-evoking pictures. N2 amplitudes were higher for pictures evoking moral disgust relative to core disgust and neutral pictures, reflecting a violation of social norms. The core disgust pictures elicited larger P3 and late positive potential (LPP) amplitudes in comparison with the moral disgust pictures which, in turn, elicited larger P3 and LPP amplitudes when compared to the neutral pictures. Taken together, these findings indicated that core and moral disgust pictures elicited different neural activities at various stages of information processing, which provided supporting evidence for the heterogeneity of disgust.

  10. Different Timing Features in Brain Processing of Core and Moral Disgust Pictures: An Event-Related Potentials Study

    PubMed Central

    Zhang, Youxue; Lou, Liandi; Ding, Daoqun

    2015-01-01

    Disgust, an emotion motivating withdrawal from offensive stimuli, protects us from the risk of biological pathogens and sociomoral violations. Homogeneity of its two types, namely, core and moral disgust has been under intensive debate. To examine the dynamic relationship between them, we recorded event-related potentials (ERPs) for core disgust, moral disgust and neutral pictures while participants performed a modified oddball task. ERP analysis revealed that N1 and P2 amplitudes were largest for the core disgust pictures, indicating automatic processing of the core disgust-evoking pictures. N2 amplitudes were higher for pictures evoking moral disgust relative to core disgust and neutral pictures, reflecting a violation of social norms. The core disgust pictures elicited larger P3 and late positive potential (LPP) amplitudes in comparison with the moral disgust pictures which, in turn, elicited larger P3 and LPP amplitudes when compared to the neutral pictures. Taken together, these findings indicated that core and moral disgust pictures elicited different neural activities at various stages of information processing, which provided supporting evidence for the heterogeneity of disgust. PMID:26011635

  11. Two-color x-ray pump x-ray probe study of the core-hole decay dynamics in XeF2

    NASA Astrophysics Data System (ADS)

    Picon, Antonio; Lehmann, C. Stefan; Southworth, Stephen; Ho, Phay; Doumy, Gilles; Kanter, Elliot; Kraessig, Bertold; March, Anne Marie; Moonshiram, Dooshaye; Young, Linda; Pratt, Steve; Ray, Dipanwita; Bostedt, Christoph; Krzywinski, Jacek; Ferguson, Ken; Carron, Sebastian; Bucher, Max; Rolles, Daniel; Erk, Benjamin; Bomme, Cedric; Rudenko, Artem; Osipov, Timur; Berrah, Nora; Cheng, Lan; Stanton, John

    2015-03-01

    To resolve the femtosecond inner-shell dynamics and the subsequent induced electron transfer in a molecule, the core-hole decay dynamics in XeF2 have been directly studied using femtosecond time-resolved x-ray pump x-ray probe coincidence imaging. The study of XeF2 molecule allows us to compare the molecular core-hole decay with the atomic case, Xe atom. To study these processes, the recently developed capability at LCLS was used to generate two-color x-ray pulses with variable delay. A time and position sensitive detector has been used to record the ion fragments in coincidence. The correlated ion kinetic energies make it possible to select and assign different excitation pathways, being able to track the atomic and the molecular core-hole decay dynamics.

  12. Carbonized medlar-core particles as a new biosorbent for removal of Cu(2+) from aqueous solution and study of its surface morphology.

    PubMed

    Samadani Langeroodi, Narges; Safaei, Elaheh

    2016-01-01

    The objective of this study was to investigate the use of carbonized medlar-core particles as a new biosorbent to remove Cu(2+) from aqueous solution. Fourier transform infrared spectroscopy and scanning electron microscopy were used to characterize the biosorbent. This paper reports the effects of adsorbent dose, pH, temperature and concentration of adsorbate. Batch isotherm studies were also performed to understand the ability of the adsorbent. The adsorption behavior of the Cu(2+) was studied using Langmuir and Freundlich adsorption isotherm models. The maximum adsorption capacity determined from the Langmuir adsorption equation has been found as 43.478 mg.g(-1) at 298.15 K. The adsorption of Cu(2+) by medlar core in carbonized form was spontaneous and endothermic. It was also found that the biosorption of Cu(2+) followed second-order kinetics. Carbonized medlar-core particles showed great potential in aqueous solution due to the high adsorption capacity. PMID:27387002

  13. Orbital dependent ultrafast charge transfer dynamics of ferrocenyl-functionalized SAMs on gold studied by core-hole clock spectroscopy

    NASA Astrophysics Data System (ADS)

    Cao, Liang; Yang, Ming; Yuan, Li; Nerngchamnong, Nisachol; Feng, Yuan-Ping; Wee, Andrew T. S.; Qi, Dong-Chen; Nijhuis, Christian A.

    2016-03-01

    Understanding the charge transport properties in general of different molecular components in a self-assembled monolayer (SAM) is of importance for the rational design of SAM molecular structures for molecular electronics. In this study, we study an important aspect of the charge transport properties, i.e. the charge transfer (CT) dynamics between the active molecular component (in this case, the ferrocenyl moieties of a ferrocenyl-n-alkanethiol SAM) and the electrode using synchrotron-based core-hole clock (CHC) spectroscopy. The characteristic CT times are found to depend strongly on the character of the ferrocenyl-derived molecular orbitals (MOs) which mediate the CT process. Furthermore, by systemically shifting the position of the ferrocenyl moiety in the SAM, it is found that the CT characteristics of the ferrocenyl MOs display distinct dependence on its distance to the electrode. These results demonstrate experimentally that the efficiency and rate of charge transport through the molecular backbone can be modulated by resonant injection of charge carriers into specific MOs.

  14. Automated tru-cut imaging-guided core needle biopsy of canine orbital neoplasia. A prospective feasibility study

    PubMed Central

    Cirla, A.; Rondena, M.; Bertolini, G.

    2016-01-01

    The purpose of this study was to evaluate the diagnostic value of imaging-guided core needle biopsy for canine orbital mass diagnosis. A second excisional biopsy obtained during surgery or necropsy was used as the reference standard. A prospective feasibility study was conducted in 23 canine orbital masses at a single centre. A complete ophthalmic examination was always followed by orbital ultrasound and computed tomography (CT) examination of the head. All masses were sampled with the patient still on the CT table using ultrasound (US) guided automatic tru-cut device. The most suitable sampling approach to the orbit was chosen each time based on the CT image analysis. One of the following different approaches was used: trans-orbital, trans-conjunctival or trans-masseteric. In all cases, the imaging-guided biopsy provided a sufficient amount of tissue for the histopathological diagnosis, which concurred with the biopsies obtained using the excisional technique. CT examination was essential for morphological diagnosis and provided detailed topographic information that allowed us to choose the safest orbital approach for the biopsy. US guided automatic tru-cut biopsy based on CT images, performed with patient still on the CT table, resulted in a minimally invasive, relatively easy, and accurate diagnostic procedure in dogs with orbital masses. PMID:27540512

  15. Developing a Consensus-Driven, Core Competency Model to Shape Future Audio Engineering Technology Curriculum: A Web-Based Modified Delphi Study

    ERIC Educational Resources Information Center

    Tough, David T.

    2009-01-01

    The purpose of this online study was to create a ranking of essential core competencies and technologies required by AET (audio engineering technology) programs 10 years in the future. The study was designed to facilitate curriculum development and improvement in the rapidly expanding number of small to medium sized audio engineering technology…

  16. Trace elements profiles, notably Hg, from a preliminary study of the Apollo 15 deep-drill core.

    NASA Technical Reports Server (NTRS)

    Jovanovic, S.; Reed, G. W., Jr.

    1972-01-01

    The possible thermal gradient near the surface during a lunation is considered together with the heat flow from the interior, the physical process of Hg migration, the results from core and trench samples from previous missions, and other temperature sensitive phenomena that may help understand the processes. U, Os, and Ru concentrations in the deep drill core samples are of potential interest and are summarized in a table. The Os tends to parallel the Hg profile with depth.

  17. Multireference study of spin-orbit coupling in the hydrides of the 6p-block elements using the model core potential method

    NASA Astrophysics Data System (ADS)

    Zeng, Tao; Fedorov, Dmitri G.; Klobukowski, Mariusz

    2010-02-01

    Careful spin-orbit multireference studies were carried out for the late p-block elements Tl, Pb, Bi, Po, At, and Rn and their hydrides using the model core potentials developed in the present work. The model core potentials were designed to treat the scalar-relativistic and spin-orbit coupling effects at the Douglas-Kroll level. The variational stability of the spin-orbit coupling operator was discussed in terms of the relativistic kinematic operators and depicted graphically. A detailed analysis of the spin-orbit multireference dissociation curves of the 6p element hydrides as well as of their atomic spectra allowed to establish the accuracy of the model core potentials with respect to all-electron calculations to be within several mÅ for re, meV (ceV) for De at the correlation level of configuration interaction (multireference perturbation theory), 30 cm-1 for ωe, and about 350 cm-1 for the low-lying atomic and molecular term and level energies. These values are expected to be the maximum error limits for the model core potentials of all the np-block elements (n =2-6). Furthermore, a good agreement with experiment requires that many terms be coupled in the spin-orbit coupling calculations. A timing study of Tl and TlH computations indicates that the model core potentials lead to 20-fold (6-fold) speedup at the level of configuration interaction (multireference perturbation theory) calculations.

  18. Mercury's Core

    NASA Astrophysics Data System (ADS)

    Peale, S. J.

    2005-05-01

    In determining Mercury's core structure from its rotational properties, the location of Cassini state 1 is crucial. Convincing radar evidence indicates that the mantle rests on a liquid layer (Margot et al. 2005), but there are no empirical constraints on the moment of inertia C/MR2, which constraints must wait for the determination of the gravitational coefficients J2 and C22 from the MESSENGER orbiting spacecraft, and an accurate determination of the obliquity of the Cassini state. Tidal and core-mantle dissipation drive the spin to the Cassini state with a time scale O(105) years, so the spin should occupy the Cassini state and thereby define its obliquity---unless there has been a recent excitation of a free precession of the spin. Another way the spin might be displaced from the Cassini state is if the variations in the orbital elements, which change the position of the Cassini state, cause the spin axis to lag behind as it attempts to follow the state. Fortunately, the solid angle the spin axis encloses as it precesses around the Cassini state is an adiabatic invariant, and it is conserved if the orbital element variations are slow compared to the precession rate. As the precession period is O(1000) years, and the time scales of orbital parameter variations are O(105) years, the spin axis should remain very close to the Cassini state if it were ever close. But how close is close? The increasing precision of the radar and eventual spacecraft measurements warrants a check on the likely proximity of the spin axis to the Cassini state. By numerically following the positions of the spin axis and Cassini state with orbital parameters varying with time scales and amplitudes comparable to the real variations, we show that the spin should remain within 1″ of the Cassini state once dissipative torques bring it there. The current spin axis position should thus define the Cassini state sufficiently to put reasonably tight constraints on the core structure

  19. Core Directions in HRD.

    ERIC Educational Resources Information Center

    1996

    This document consists of four papers presented at a symposium on core directions in human resource development (HRD) moderated by Verna Willis at the 1996 conference of the Academy of Human Resource Development. "Reengineering the Organizational HRD Function: Two Case Studies" (Neal Chalofsky) reports an action research study in which the…

  20. Molecular dynamics study of a one component soft-core system: thermodynamic properties in the crystalline state.

    PubMed

    Habasaki, Junko; Ueda, Akira

    2012-05-21

    In the present work, molecular dynamics (MD) simulations have been performed to study thermal properties of crystals in a one component soft-core system. The system was examined along the phase-diagram using the compressibility factor, P[combining tilde](T*) ≡PV/NkBT plotted against the reduced density ρ* (or reduced temperature, T*). The specific heat, CV, of the system is presented as the function of P[combining tilde](ρ*) and also as the function of the reduced potential energy, U*. These CV values are expressed using coefficients of the expansion around the harmonic term. We also derived the expression for entropy using these coefficients. The contribution of an anharmonic term in the specific heat and entropy was clarified by this. These results are compared with those obtained from the fluctuation of kinetic energy. Several quantities related to the distribution of time dependent reduced temperature and dynamical compressibility factor (PV/NkBT)t are also examined and three T* regions of thermal behaviors are characterized. In the diagram, the glass transition by cooling or compression can be treated on the same basis. Results of the present work will be helpful for a better understanding of the changes in the specific heat during the glass transition in the future works.

  1. Molecular dynamics study of one-component soft-core system: Thermodynamic properties in the supercooled liquid and glassy states

    NASA Astrophysics Data System (ADS)

    Habasaki, Junko; Ueda, Akira

    2013-04-01

    Molecular dynamics simulations were performed to study the thermal properties of a supercooled liquid near the glass transition regime and of glasses in a one-component soft-core system with the pair potential φn(r) = ɛ(σ/r)n, in which n = 12. The results are examined along a phase diagram, in which the compressibility factor defined by tilde P(ρ ^{ast}) equiv PV/Nk_B T is plotted against the reduced density ρ* = ρ(ɛ/kBT)3/n (or the reduced temperature T* = ρ*-n/3). Similarly, a time-dependent dynamical compressibility factor can be plotted against the time-dependent reduced density ρ _t ^* = ρ (\\varepsilon /k_B T_t^*)^{3/n} (or the reduced time-dependent temperature). Analytical expressions of the specific heats CV and CP and of the entropy, S, were obtained as a function of tilde P(ρ ^{ast}) or of the scaled potential U*. Even for a rapid cooling process, the CV values are found to be affected by non-equilibrium relaxations in the ρ _0^* > 1.3 region, where ρ _0^* is the given initial value of ρ _t^*. The problem of the Kauzmann paradox is discussed using these expressions. The fluctuation of the time-dependent temperature, Tt*, which determines CV, is characterized by the spectra that are obtained by multitaper methods. The thermal fluctuation along the non-equilibrium relaxation under NVE conditions was also examined.

  2. NLOphoric Red Emitting Bis Coumarins with O-BF(2)-O core - Synthesis, Photophysical Properties and DFT Studies.

    PubMed

    Tathe, Abhinav B; Sekar, Nagaiyan

    2016-03-01

    The red emitting dyes were synthesized by employing coumarin core as a donor and boron-bonded coumarin as an acceptor. 7-(N,N-Diethylamino)-coumarin 3-aldehyde was reacted with 3-acetyl-4-hydroxy-coumarin, 7-(N,N-diethylamino)-3-acetyl-4-hydroxy-coumarin and 3-acetyl-4-hydroxy-1-methyl-quinolone to form the corresponding chalcones. The synthesized chalcones were though red shifted as compared to the parent coumarin, and were not emitting in red region. The BF2-complexation was used as a tool to introduce a red shift in the molecules. The BF2-complexes synthesized were found to be red emitting and show higher one photon absorption cross section. The solvatochromism shown by these dyes was studied in the light of solvent polarity parameters. DFT calculations were used to understand the photophysical properties of the synthesized dyes. NLO properties of the dyes were estimated by solvatochromic and computational methods. All the molecules synthesized were characterised with the HRMS and NMR spectral Analysis.

  3. Magnetic and transport studies of core-shell nanorods based on metallic oxide ferromagnet SrRuO3

    NASA Astrophysics Data System (ADS)

    Zheng, M.; Li, X. Y.; Zhu, Q. X.; Li, H. R.; Shi, L.; Li, X. M.; Zheng, R. K.

    2016-01-01

    This study presents the synthesis of perovskite metal-semiconductor core-shell heterostructures by sputtering SrRuO3 (SRO) shell layer on vertically aligned hydrothermally produced ZnO nanorods. Compared to the two-dimensional SRO films, the magnetic behaviors of the SRO shells on ZnO nanorods are morphology and thickness dependent, as reflected by the magnetic isotropy effects and the appearance of double-step magnetic hysteresis loops caused by nanograin-induced disorder and uncompensated spin at the surface and interface. The appearance of low-temperature resistance minimum and the good fitting of the low-temperature resistance data to a theoretical model establish the emergence of weak localization effect in the SRO shells, whose strength can be reinforced by a magnetic field. In addition, an apparent low-resistance Ohmic contact was realized in the ZnO/SRO heterojunctions due to the lower work function of the SRO. This, together with the absence of the Schottky barrier at the interface, demonstrates that the ZnO/SRO nanostructures could hold great promise for applications in advanced electron field emitters.

  4. Evidence for Gamow-Teller Decay of ^{78}Ni Core from Beta-Delayed Neutron Emission Studies.

    PubMed

    Madurga, M; Paulauskas, S V; Grzywacz, R; Miller, D; Bardayan, D W; Batchelder, J C; Brewer, N T; Cizewski, J A; Fijałkowska, A; Gross, C J; Howard, M E; Ilyushkin, S V; Manning, B; Matoš, M; Mendez, A J; Miernik, K; Padgett, S W; Peters, W A; Rasco, B C; Ratkiewicz, A; Rykaczewski, K P; Stracener, D W; Wang, E H; Wolińska-Cichocka, M; Zganjar, E F

    2016-08-26

    The β-delayed neutron emission of ^{83,84}Ga isotopes was studied using the neutron time-of-flight technique. The measured neutron energy spectra showed emission from states at excitation energies high above the neutron separation energy and previously not observed in the β decay of midmass nuclei. The large decay strength deduced from the observed intense neutron emission is a signature of Gamow-Teller transformation. This observation was interpreted as evidence for allowed β decay to ^{78}Ni core-excited states in ^{83,84}Ge favored by shell effects. We developed shell model calculations in the proton fpg_{9/2} and neutron extended fpg_{9/2}+d_{5/2} valence space using realistic interactions that were used to understand measured β-decay lifetimes. We conclude that enhanced, concentrated β-decay strength for neutron-unbound states may be common for very neutron-rich nuclei. This leads to intense β-delayed high-energy neutron and strong multineutron emission probabilities that in turn affect astrophysical nucleosynthesis models. PMID:27610848

  5. Evidence for Gamow-Teller Decay of 78Ni Core from Beta-Delayed Neutron Emission Studies

    NASA Astrophysics Data System (ADS)

    Madurga, M.; Paulauskas, S. V.; Grzywacz, R.; Miller, D.; Bardayan, D. W.; Batchelder, J. C.; Brewer, N. T.; Cizewski, J. A.; Fijałkowska, A.; Gross, C. J.; Howard, M. E.; Ilyushkin, S. V.; Manning, B.; Matoš, M.; Mendez, A. J.; Miernik, K.; Padgett, S. W.; Peters, W. A.; Rasco, B. C.; Ratkiewicz, A.; Rykaczewski, K. P.; Stracener, D. W.; Wang, E. H.; Wolińska-Cichocka, M.; Zganjar, E. F.

    2016-08-01

    The β -delayed neutron emission of Ga,8483 isotopes was studied using the neutron time-of-flight technique. The measured neutron energy spectra showed emission from states at excitation energies high above the neutron separation energy and previously not observed in the β decay of midmass nuclei. The large decay strength deduced from the observed intense neutron emission is a signature of Gamow-Teller transformation. This observation was interpreted as evidence for allowed β decay to 78Ni core-excited states in Ge,8483 favored by shell effects. We developed shell model calculations in the proton f p g9 /2 and neutron extended f p g9 /2+d5 /2 valence space using realistic interactions that were used to understand measured β -decay lifetimes. We conclude that enhanced, concentrated β -decay strength for neutron-unbound states may be common for very neutron-rich nuclei. This leads to intense β -delayed high-energy neutron and strong multineutron emission probabilities that in turn affect astrophysical nucleosynthesis models.

  6. A genome-wide association study reveals genes associated with fusarium ear rot resistance in a maize core diversity panel.

    PubMed

    Zila, Charles T; Samayoa, L Fernando; Santiago, Rogelio; Butrón, Ana; Holland, James B

    2013-11-01

    Fusarium ear rot is a common disease of maize that affects food and feed quality globally. Resistance to the disease is highly quantitative, and maize breeders have difficulty incorporating polygenic resistance alleles from unadapted donor sources into elite breeding populations without having a negative impact on agronomic performance. Identification of specific allele variants contributing to improved resistance may be useful to breeders by allowing selection of resistance alleles in coupling phase linkage with favorable agronomic characteristics. We report the results of a genome-wide association study to detect allele variants associated with increased resistance to Fusarium ear rot in a maize core diversity panel of 267 inbred lines evaluated in two sets of environments. We performed association tests with 47,445 single-nucleotide polymorphisms (SNPs) while controlling for background genomic relationships with a mixed model and identified three marker loci significantly associated with disease resistance in at least one subset of environments. Each associated SNP locus had relatively small additive effects on disease resistance (±1.1% on a 0-100% scale), but nevertheless were associated with 3 to 12% of the genotypic variation within or across environment subsets. Two of three identified SNPs colocalized with genes that have been implicated with programmed cell death. An analysis of associated allele frequencies within the major maize subpopulations revealed enrichment for resistance alleles in the tropical/subtropical and popcorn subpopulations compared with other temperate breeding pools. PMID:24048647

  7. NLOphoric Red Emitting Bis Coumarins with O-BF(2)-O core - Synthesis, Photophysical Properties and DFT Studies.

    PubMed

    Tathe, Abhinav B; Sekar, Nagaiyan

    2016-03-01

    The red emitting dyes were synthesized by employing coumarin core as a donor and boron-bonded coumarin as an acceptor. 7-(N,N-Diethylamino)-coumarin 3-aldehyde was reacted with 3-acetyl-4-hydroxy-coumarin, 7-(N,N-diethylamino)-3-acetyl-4-hydroxy-coumarin and 3-acetyl-4-hydroxy-1-methyl-quinolone to form the corresponding chalcones. The synthesized chalcones were though red shifted as compared to the parent coumarin, and were not emitting in red region. The BF2-complexation was used as a tool to introduce a red shift in the molecules. The BF2-complexes synthesized were found to be red emitting and show higher one photon absorption cross section. The solvatochromism shown by these dyes was studied in the light of solvent polarity parameters. DFT calculations were used to understand the photophysical properties of the synthesized dyes. NLO properties of the dyes were estimated by solvatochromic and computational methods. All the molecules synthesized were characterised with the HRMS and NMR spectral Analysis. PMID:26662811

  8. A Panel of Recombinant Mucins Carrying a Repertoire of Sialylated O-Glycans Based on Different Core Chains for Studies of Glycan Binding Proteins.

    PubMed

    Cherian, Reeja Maria; Jin, Chunsheng; Liu, Jining; Karlsson, Niclas G; Holgersson, Jan

    2015-08-12

    Sialylated glycans serve as key elements of receptors for many viruses, bacteria, and bacterial toxins. The microbial recognition and their binding specificity can be affected by the linkage of the terminal sugar residue, types of underlying sugar chains, and the nature of the entire glycoconjugate. Owing to the pathobiological significance of sialylated glycans, we have engineered Chinese hamster ovary (CHO) cells to secrete mucin-type immunoglobulin-fused proteins carrying terminal α2,3- or α2,6-linked sialic acid on defined O-glycan core saccharide chains. Besides stably expressing P-selectin glycoprotein ligand-1/mouse immunoglobulin G2b cDNA (PSGL-1/mIgG2b), CHO cells were stably transfected with plasmids encoding glycosyltransferases to synthesize core 2 (GCNT1), core 3 (B3GNT6), core 4 (GCNT1 and B3GNT6), or extended core 1 (B3GNT3) chains with or without the type 1 chain-encoding enzyme B3GALT5 and ST6GAL1. Western blot and liquid chromatography-mass spectrometry analysis confirmed the presence of core 1, 2, 3, 4, and extended core 1 chains carrying either type 1 (Galb3GlcNAc) or type 2 (Galb4GlcNAc) outer chains with or without α2,6-linked sialic acids. This panel of recombinant mucins carrying a repertoire of sialylated O-glycans will be important tools in studies aiming at determining the fine O-glycan binding specificity of sialic acid-specific microbial adhesins and mammalian lectins.

  9. A Panel of Recombinant Mucins Carrying a Repertoire of Sialylated O-Glycans Based on Different Core Chains for Studies of Glycan Binding Proteins

    PubMed Central

    Maria Cherian, Reeja; Jin, Chunsheng; Liu, Jining; Karlsson, Niclas G.; Holgersson, Jan

    2015-01-01

    Sialylated glycans serve as key elements of receptors for many viruses, bacteria, and bacterial toxins. The microbial recognition and their binding specificity can be affected by the linkage of the terminal sugar residue, types of underlying sugar chains, and the nature of the entire glycoconjugate. Owing to the pathobiological significance of sialylated glycans, we have engineered Chinese hamster ovary (CHO) cells to secrete mucin-type immunoglobulin-fused proteins carrying terminal α2,3- or α2,6-linked sialic acid on defined O-glycan core saccharide chains. Besides stably expressing P-selectin glycoprotein ligand-1/mouse immunoglobulin G2b cDNA (PSGL-1/mIgG2b), CHO cells were stably transfected with plasmids encoding glycosyltransferases to synthesize core 2 (GCNT1), core 3 (B3GNT6), core 4 (GCNT1 and B3GNT6), or extended core 1 (B3GNT3) chains with or without the type 1 chain-encoding enzyme B3GALT5 and ST6GAL1. Western blot and liquid chromatography-mass spectrometry analysis confirmed the presence of core 1, 2, 3, 4, and extended core 1 chains carrying either type 1 (Galβ3GlcNAc) or type 2 (Galβ4GlcNAc) outer chains with or without α2,6-linked sialic acids. This panel of recombinant mucins carrying a repertoire of sialylated O-glycans will be important tools in studies aiming at determining the fine O-glycan binding specificity of sialic acid-specific microbial adhesins and mammalian lectins. PMID:26274979

  10. Non-invasive monitoring of core body temperature rhythms over 72 h in 10 bedridden elderly patients with disorders of consciousness in a Japanese hospital: a pilot study.

    PubMed

    Matsumoto, Masaru; Sugama, Junko; Okuwa, Mayumi; Dai, Misako; Matsuo, Junko; Sanada, Hiromi

    2013-01-01

    The purpose of this study was to elucidate the body core temperature rhythms of bedridden elderly patients with disorders of consciousness (DOC) in a Japanese hospital using a simple, non-invasive, deep-body thermometer. We measured body core temperature on the surface of abdomen in 10 bedridden elderly patients with DOC continuously over 72 h. A non-heated core body temperature thermometer was used. The cycle of the body core temperature rhythm was initially derived by using the least squares method. Then, based on that rhythm, the mean, amplitude, and times of day of the highest and lowest body temperatures during the optimum cycle were determined using the cosinor method. We found a 24-h cycle in seven of the 10 patients. One patient had a 6-h, one a 12-h, and one a 63-h cycle. The mean value of the cosine curve in the respective optimum cycles was 36.48 ± 0.34 °C, and the amplitude was 0.22 ± 0.09 °C. Of the seven subjects with 24-h cycles, the highest body temperature occurred between 12:58 and 14:44 h in four. In addition to 24-h cycles of core temperature rhythm, short cycles of 12 and 6-h and a long cycle of 63-h were seen. In order to understand the temperature rhythms of bedridden elderly patients with DOC, it is necessary to monitor their core body temperatures, ideally using a simple, non-invasive device. In the future, it will be important to investigate the relationship of the core temperature rhythm to nursing care and living environment.

  11. Pressure Core Characterization

    NASA Astrophysics Data System (ADS)

    Santamarina, J. C.

    2014-12-01

    Natural gas hydrates form under high fluid pressure and low temperature, and are found in permafrost, deep lakes or ocean sediments. Hydrate dissociation by depressurization and/or heating is accompanied by a multifold hydrate volume expansion and host sediments with low permeability experience massive destructuration. Proper characterization requires coring, recovery, manipulation and testing under P-T conditions within the stability field. Pressure core technology allows for the reliable characterization of hydrate bearing sediments within the stability field in order to address scientific and engineering needs, including the measurement of parameters used in hydro-thermo-mechanical analyses, and the monitoring of hydrate dissociation under controlled pressure, temperature, effective stress and chemical conditions. Inherent sampling effects remain and need to be addressed in test protocols and data interpretation. Pressure core technology has been deployed to study hydrate bearing sediments at several locations around the world. In addition to pressure core testing, a comprehensive characterization program should include sediment analysis, testing of reconstituted specimens (with and without synthetic hydrate), and in situ testing. Pressure core characterization technology can be used to study other gas-charged formations such as deep sea sediments, coal bed methane and gas shales.

  12. Co-electrospinning fabrication and study of structural and electromagnetic interference-shielding effectiveness of TiO2/SiO2 core-shell nanofibers

    NASA Astrophysics Data System (ADS)

    Nakhaei, Omolfajr; Shahtahmassebi, Nasser; Rezaee Roknabadi, Mahmood; Behdani, Mohammad

    2016-05-01

    The present paper reports novel outcome comprising experimental results on electromagnetic interference (EMI) shielding and radar signal absorption characteristics of one-dimensional (1D) TiO2/SiO2 core-shell nanofibers. 1D TiO2/SiO2 core-shell nanofibers with various concentrations of nanoparticles (NPs) were fabricated using a single-nozzle co-electrospinning method. The core-shell structure of polyvinylpyrrolidone/polyacrylonitrile nanofibers with NPs have been electrospun from the homogeneous solution of polyvinylpyrrolidone (PVP and TiO2 NPs, as core) and polyacrylonitrile (PAN and SiO2 NPs, as shell). The morphologies and structures of TiO2/SiO2 core-shell nanofibers were characterized by XRD, FTIR, EDS, and SEM images. Microwave absorption properties of the synthesized nanofibers were studied using a vector network analyzer between 2 and 20 GHz at room temperature. The maximum EMI-shielding effectiveness of 150 dB is obtained with the dominant shielding mechanism of absorption of EM radiation. The excellent microwave absorption properties of the composites nanofibers are attributed to the special 1D fibrous structure and the effective dielectric loss.

  13. Difference in fibril core stability between two tau four-repeat domain proteins: a hydrogen-deuterium exchange coupled to mass spectrometry study.

    PubMed

    Ramachandran, Gayathri; Udgaonkar, Jayant B

    2013-12-10

    One of the signatures of Alzheimer's disease and tauopathies is fibrillization of the microtubule-associated protein tau. The purpose of this study was to compare the high-resolution structure of fibrils formed by two different tau four-repeat domain constructs, tau4RD and tauK18, using hydrogen-deuterium exchange coupled to mass spectrometry as a tool. While the two fibrils are found to be constructed on similar structural principles, the tauK18 fibril has a slightly more stable core. This difference in fibril core stability appears to be reflective of the mechanistic differences in the aggregation pathways of the two proteins. PMID:24256615

  14. Glycerol capped PbS/CdS core/shell nanoparticles at different molar ratio and its application in biosensors: An optical properties study

    NASA Astrophysics Data System (ADS)

    Das, D.; Hussain, A. M. P.

    2016-05-01

    Glycerol capped PbS/CdS core/shell type nanoparticles fabricated with two different molar ratios are characterized for study of structural and optical properties. The X-ray diffraction (XRD) pattern exhibits cubic phased polycrystalline nanocrystals. The calculated grain sizes from Williamson-Hall plot were found to be around 6 nm with increased strain. HRTEM investigation confirms the formation of core/shell nanostructures and the sizes of the particles were found to be around 7 nm which is in good agreement with the results of the W-H plot. An increase of band gap with the decrease in precursor concentration is confirmed from the blue shift in the absorption spectra and also from Tauc plot. A clear blue shifted intense emission is observed in the photoluminescence spectra with decrease in particle size. Intense luminescence from the core/shell nanostructure may be applied in bio labelling and biosensors.

  15. Core disgust and moral disgust are related to distinct spatiotemporal patterns of neural processing: an event-related potential study.

    PubMed

    Luo, Yu; Shen, Weilin; Zhang, Yu; Feng, Ting-yong; Huang, Hao; Li, Hong

    2013-10-01

    Core disgust is thought to rely more on sensory and perceptual processes, whereas moral disgust is thought to rely more on social evaluation processes. However, little is known about the neurocognitive mechanisms underlying these two types of disgust. We recorded event-related potentials (ERPs) from participants while they performed a lexical decision task in which core- and moral-disgust words were intermixed with neutral words and pseudowords. Lexical judgment was faster for coredisgust words and slower for moral-disgust words, relative to the neutral words. Core-disgust words, relative to neutral words, elicited a larger early posterior negative (EPN), a larger N320, a smaller N400, and a larger late positive component (LPC), whereas moral disgust words elicited a smaller N320 and a larger N400 than neutral words. These results suggest that the N320 and N400 components are particularly sensitive to the neurocognitive processes that overlap in processing both core and moral disgust, whereas the EPN and LPC may reflect process that are particularly sensitive to core disgust.

  16. Magnetization measurements and XMCD studies on ion irradiated iron oxide and core-shell iron/iron-oxide nanomaterials

    SciTech Connect

    Kaur, Maninder; Qiang, You; Jiang, Weilin; Pearce, Carolyn; McCloy, John S.

    2014-12-02

    Magnetite (Fe3O4) and core-shell iron/iron-oxide (Fe/Fe3O4) nanomaterials prepared by a cluster deposition system were irradiated with 5.5 MeV Si2+ ions and the structures determined by x-ray diffraction as consisting of 100% magnetite and 36/64 wt% Fe/FeO, respectively. However, x-ray magnetic circular dichroism (XMCD) indicates similar surfaces in the two samples, slightly oxidized and so having more Fe3+ than the expected magnetite structure, with XMCD intensity much lower for the irradiated core-shell samples indicating weaker magnetism. X-ray absorption spectroscopy (XAS) data lack the signature for FeO, but the irradiated core-shell system consists of Fe-cores with ~13 nm of separating oxide crystallite, so it is likely that FeO exists deeper than the probe depth of the XAS (~5 nm). Exchange bias (Hex) for both samples becomes increasingly negative as temperature is lowered, but the irradiated Fe3O4 sample shows greater sensitivity of cooling field on Hex. Loop asymmetries and Hex sensitivities of the irradiated Fe3O4 sample are due to interfaces and interactions between grains which were not present in samples before irradiation as well as surface oxidation. Asymmetries in the hysteresis curves of the irradiated core/shell sample are related to the reversal mechanism of the antiferromagnetic FeO and possibly some near surface oxidation.

  17. Real-space pseudopotential study of vibrational properties and Raman spectra in Si-Ge core-shell nanocrystals.

    PubMed

    Bobbitt, N Scott; Chelikowsky, James R

    2016-03-28

    We examine the vibrational properties and Raman spectra of Si-Ge core-shell nanostructures using real-space pseudopotentials constructed within density functional theory. Our method uses no empirical parameters, unlike many popular methods for predicting Raman spectra for nanocrystals. We find the dominant features of the Raman spectrum for the Si-Ge core-shell structure to be a superposition of the Raman spectra of the Ge and Si nanocrystals with optical peaks around 300 and 500 cm(-1), respectively. We also find a Si-Ge "interface" peak at 400 cm(-1). The Ge shell causes the Si core to expand from the equilibrium structure. This strain induces significant redshift in the Si contribution to the vibrational and Raman spectra, while the Ge shell is largely unstrained and does not exhibit this shift. We find that the ratio of peak heights is strongly related to the relative size of the core and shell regions. This finding suggests that Raman spectroscopy may be used to characterize the size of the core and shell in these structures. PMID:27036430

  18. Emotional Intolerance and Core Features of Anorexia Nervosa: A Dynamic Interaction during Inpatient Treatment? Results from a Longitudinal Diary Study

    PubMed Central

    Stroe-Kunold, Esther; Friederich, Hans-Christoph; Stadnitski, Tatjana; Wesche, Daniela; Herzog, Wolfgang; Schwab, Michael; Wild, Beate

    2016-01-01

    Objective The role of emotion dysregulation with regard to the psychopathology of anorexia nervosa (AN) is increasingly discussed. It is both assumed that AN symptoms have an impact on difficulties in tolerating aversive emotions and that—conversely—emotion dysregulation influences AN. To date, such conclusions are drawn on the basis of cross-sectional data not allowing for inferences on the temporal dynamics. The current study investigates the longitudinal interaction between emotional intolerance and core AN symptoms over the course of inpatient treatment by comparing patients with high (BMI<15 kg/m2) vs. low symptom severity (HSS vs. LSS). Method The study adopted a longitudinal, process-oriented design with N = 16 analysed electronic diaries. Throughout the course of their inpatient treatment, the patients answered questions daily about emotional intolerance and their AN-specific cognitions and behaviours. The temporal dynamics between emotional intolerance and these variables were analysed using a multivariate time series approach. Results The time series of the processes under investigation adequately reflected the individual treatment courses. The majority of significant linear time trends was found for HSS patients. Most importantly, analysis revealed significant temporal interactions between emotional intolerance and AN symptoms in almost 70% of HSS patients. Thereby, up to 37% of variance in eating restraint and up to 23% in weight concern could be attributed to changes in emotional intolerance. Conclusions The findings support the notion that intolerable unpleasant emotions in severely affected AN patients influence their psychopathology. Additionally, time series analysis outlined the inter-individual heterogeneity of psychosomatic treatment courses of AN patients. PMID:27191959

  19. A Giant Metrewave Radio Telescope Multifrequency Radio Study of the Isothermal Core of the Poor Galaxy Cluster AWM 4

    NASA Astrophysics Data System (ADS)

    Giacintucci, Simona; Vrtilek, Jan M.; Murgia, Matteo; Raychaudhury, Somak; O'Sullivan, Ewan J.; Venturi, Tiziana; David, Laurence P.; Mazzotta, Pasquale; Clarke, Tracy E.; Athreya, Ramana M.

    2008-07-01

    We present a detailed radio morphological study and spectral analysis of the wide-angle tail radio source 4C +24.36 associated with the dominant galaxy in the relaxed galaxy cluster AWM 4. Our study is based on new high-sensitivity GMRT observations at 235, 327, and 610 MHz and on literature and archival data at other frequencies. We find that the source major axis is likely oriented at a small angle with respect to the plane of the sky. The wide-angle tail morphology can be reasonably explained by adopting a simple hydrodynamical model in which both ram pressure (driven by the motion of the host galaxy) and buoyancy forces contribute to bend the radio structure. The spectral index progressively steepens along the source major axis from α ~ 0.3 in the region close to the radio nucleus to beyond 1.5 in the lobes. The results of the analysis of the spectral index image allow us to derive an estimate of the radiative age of the source of ~160 Myr. The cluster X-ray-emitting gas has a relaxed morphology and short cooling time, but its temperature profile is isothermal out to at least 160 kpc from the center. Therefore, we seek evidence of energy ejection from the central AGN to prevent catastrophic cooling. We find that the energy injected by 4C +24.36 in the form of synchrotron luminosity during its lifetime is far less than the energy required to maintain the high gas temperature in the core. We also find that it is not possible for the central source to eject the requisite energy in the intracluster gas in terms of the enthalpy of buoyant bubbles of relativistic fluid, without creating discernible large cavities in the existing X-ray XMM-Newton observations.

  20. Imitation (Rather than Core Language) Predicts Pragmatic Development in Young Children with ASD: A Preliminary Longitudinal Study Using CDI Parental Reports

    ERIC Educational Resources Information Center

    Miniscalco, Carmela; Rudling, Maja; Råstam, Maria; Gillberg, Christopher; Johnels, Jakob Åsberg

    2014-01-01

    Background: Research in the last decades has clearly pointed to the important role of language and communicative level when trying to understand developmental trajectories in children with autism spectrum disorders (ASD). Aims: The purpose of this longitudinal study was to investigate whether (1) "core language skills", measured as…

  1. Unemployment in the Urban Core: An Analysis of Thirty Cities with Policy Recommendations. Praeger Special Studies in U.S. Economic, Social, and Political Issues.

    ERIC Educational Resources Information Center

    Friedlander, Stanley L.

    This study explores the determinants of urban unemployment in 30 major cities, particularly in the inner core slums among nonwhites and youth. Using data for 1960, a year of recession, and 1966, a year of prosperity, the author found that a factor which may be important under one set of economic conditions is not so in another cycle. Although…

  2. "I'm No Longer Just Teaching History." Professional Development for Teaching Common Core State Standards for Literacy in Social Studies

    ERIC Educational Resources Information Center

    Gilles, Carol; Wang, Yang; Smith, Joanne; Johnson, Danielle

    2013-01-01

    This article describes Common Core State Standards (CCSS) that teach literacy strategies to all content teachers in the U.S. It describes how three Social Studies teachers from three middle schools incorporated literacy strategies into their content areas and exposed their reading strategies. These teachers were asked to identify and write down…

  3. Profiling of energy deposition fields in a modular HTHR with annular core: Computational/experimental studies at the ASTRA critical facility

    SciTech Connect

    Boyarinov, V. F.; Garin, V. P.; Glushkov, E. S.; Zimin, A. A.; Kompaniets, G. V.; Nevinitsa, V. A.; Polyakov, D. N.; Ponomarev, A. S.; Ponomarev-Stepnoi, N. N.; Smirnov, O. N.; Fomichenko, P. A.; Chunyaev, E. I.; Marova, E. V.; Sukharev, Yu. P.

    2010-12-15

    The paper presents the results obtained from the computational/experimental studies of the spatial distribution of the {sup 235}U fission reaction rate in a critical assembly with an annular core and poison profiling elements inserted into the inner graphite reflector. The computational analysis was carried out with the codes intended for design computation of an HTHR-type reactor.

  4. A Study of Business Division Core Curriculum Strengths and Weaknesses as Perceived by Graduates of the Classes of 1980 and 1981 at Roger Williams College.

    ERIC Educational Resources Information Center

    Cedergren, Kenneth W.

    College graduates' evaluations of 12 core courses in the business administration curriculum were assessed as a followup to a 1976 study. The students were bachelor's degree graduates from Roger Williams College with majors in general business administration, management, and accounting and marketing. Each course was rated on: course satisfaction,…

  5. Nursing Faculty Professional Development: A Study Using the National League for Nursing (NLN) Core Competencies for Nurse Educators for Development of Novice to Expert Nurse Educators

    ERIC Educational Resources Information Center

    Luoma, Kari L.

    2013-01-01

    The purpose of this quantitative research study was to identify core competencies that are most significant for nursing faculty to develop as they transition from novice to expert faculty. Professional development in a systematic approach may guide faculty to learn what is significant as they progress in the nurse faculty role. A quantitative…

  6. Fissioning Plasma Core Reactor

    NASA Technical Reports Server (NTRS)

    Albright, Dennis; Butler, Carey; West, Nicole; Cole, John W. (Technical Monitor)

    2002-01-01

    Institute for Scientific Research, Inc. (ISR) research program consist of: 1.Study core physics by adapting existing codes: MCNP4C - Monte Carlo code; COMBINE/VENTURE - diffusion theory; SCALE4 - Monte Carlo, with many utility codes. 2. Determine feasibility and study major design parameters: fuel selection, temperature and reflector sizing. 3. Study reactor kinetics: develop QCALC1 to model point kinetics; study dynamic behavior of the power release.

  7. A carbon, nitrogen, and sulfur elemental and isotopic study in dated sediment cores from the Louisiana Shelf

    USGS Publications Warehouse

    Rosenbauer, R.J.; Swarzenski, P.W.; Kendall, C.; Orem, W.H.; Hostettler, F.D.; Rollog, M.E.

    2009-01-01

    Three sediment cores were collected off the Mississippi River delta on the Louisiana Shelf at sites that are variably influenced by recurring, summer-time water-column hypoxia and fluvial loadings. The cores, with established chronology, were analyzed for their respective carbon, nitrogen, and sulfur elemental and isotopic composition to examine variable organic matter inputs, and to assess the sediment record for possible evidence of hypoxic events. Sediment from site MRJ03-3, which is located close to the Mississippi Canyon and generally not influenced by summer-time hypoxia, is typical of marine sediment in that it contains mostly marine algae and fine-grained material from the erosion of terrestrial C4 plants. Sediment from site MRJ03-2, located closer to the mouth of the Mississippi River and at the periphery of the hypoxic zone (annual recurrence of summer-time hypoxia >50%), is similar in composition to core MRJ03-3, but exhibits more isotopic and elemental variability down-core, suggesting that this site is more directly influenced by river discharge. Site MRJ03-5 is located in an area of recurring hypoxia (annual recurrence >75%), and is isotopically and elementally distinct from the other two cores. The carbon and nitrogen isotopic composition of this core prior to 1960 is similar to average particulate organic matter from the lower Mississippi River, and approaches the composition of C3 plants. This site likely receives a greater input of local terrestrial organic matter to the sediment. After 1960 and to the present, a gradual shift to higher values of ??13C and ??15N and lower C:N ratios suggests that algal input to these shelf sediments increased as a result of increased productivity and hypoxia. The values of C:S and ??34S reflect site-specific processes that may be influenced by the higher likelihood of recurring seasonal hypoxia. In particular, the temporal variations in the C:S and ??34S down-core are likely caused by changes in the rate of

  8. Core properties and mobility of the basal screw dislocation in wurtzite GaN: a density functional theory study

    NASA Astrophysics Data System (ADS)

    Belabbas, I.; Chen, J.; Heggie, M. I.; Latham, C. D.; Rayson, M. J.; Briddon, P. R.; Nouet, G.

    2016-10-01

    We have performed first principles simulations, based on density functional theory (DFT), to investigate the core properties of the basal a -type screw dislocation in wurtzite gallium nitride. Our calculations demonstrate that the fully coordinated shuffle core configuration is the most energetically favourable. The calculated electronic structure of the a -type screw dislocation was found to exhibit exclusively shallow gap states which are not associated with any extended metallization. This may explain why a -type screw dislocations are less detrimental to the performance of GaN based electronic devices than c -type screw dislocations.

  9. Experimental study of low-loss single-mode performance in anti-resonant hollow-core fibers.

    PubMed

    Yu, Fei; Xu, Mengrong; Knight, Jonathan C

    2016-06-13

    Anti-resonant hollow-core fibers are optical fiber waveguides which exhibit very low dispersion, high damage threshold and ultra-low nonlinear response. However, they typically deliver the light in several spatial modes, whereas their application usually requires that they support a single spatial mode. We report the principles, fabrication, demonstration and characterization of anti-resonant hollow-core fibres with strong differential modal attenuations and low overall attenuations. These fibers perform as single-mode and are eminently suitable for delivery of powerful ultrashort optical pulses in machining, cutting, welding and multiphoton microscopy applications. PMID:27410316

  10. Postmortem Study of Validation of Low Signal on Fat-Suppressed T1-Weighted Magnetic Resonance Imaging as Marker of Lipid Core in Middle Cerebral Artery Atherosclerosis

    PubMed Central

    Yang, Wen-Jie; Zhao, Hai-Lu; Niu, Chun-Bo; Zhang, Bing; Xu, Yun; Wong, Ka-Sing; Ng, Ho-Keung

    2016-01-01

    Background and Purpose— High signal on T1-weighted fat-suppressed images in middle cerebral artery plaques on ex vivo magnetic resonance imaging was verified to be intraplaque hemorrhage histologically. However, the underlying plaque component of low signal on T1-weighted fat-suppressed images (LST1) has never been explored. Based on our experience, we hypothesized that LST1 might indicate the presence of lipid core within intracranial plaques. Methods— 1.5 T magnetic resonance imaging was performed in the postmortem brains to scan the cross sections of bilateral middle cerebral arteries. Then middle cerebral artery specimens were removed for histology processing. LST1 presence was identified on magnetic resonance images, and lipid core areas were measured on the corresponding histology sections. Results— Total 76 middle cerebral artery locations were included for analysis. LST1 showed a high specificity (96.9%; 95% confidence interval, 82.0%–99.8%) but a low sensitivity (38.6%; 95% confidence interval, 24.7%–54.5%) for detecting lipid core of all areas. However, the sensitivity increased markedly (81.2%; 95% confidence interval, 53.7%–95.0%) when only lipid cores of area ≥0.80 mm2 were included. Mean lipid core area was 5× larger in those with presence of LST1 than in those without (1.63±1.18 mm2 versus 0.32±0.31 mm2; P=0.003). Conclusions— LST1 is a promising imaging biomarker of identifying intraplaque lipid core, which may be useful to distinguish intracranial atherosclerotic disease from other intracranial vasculopathies and to assess plaque vulnerability for risk stratification of patients with intracranial atherosclerotic disease. In vivo clinical studies are required to explore the correlation between LST1 and clinical outcomes of patients with intracranial atherosclerotic disease. PMID:27462119

  11. Nickel/carbon core/shell nanotubes: Lanthanum nickel alloy catalyzed synthesis, characterization and studies on their ferromagnetic and lithium-ion storage properties

    SciTech Connect

    Anthuvan Rajesh, John; Pandurangan, Arumugam; Senthil, Chenrayan; Sasidharan, Manickam

    2014-12-15

    Highlights: • Ni/CNTs core/shell structure was synthesized using LaNi{sub 5} alloy catalyst by CVD. • The magnetic and lithium-ion storage properties of Ni/CNTs structure were studied. • The specific Ni/CNTs structure shows strong ferromagnetic property with large coercivity value of 446.42 Oe. • Ni/CNTs structure shows enhanced electrochemical performance in terms of stable capacity and better rate capability. - Abstract: A method was developed to synthesize ferromagnetic nickel core/carbon shell nanotubes (Ni/CNTs) by chemical vapor deposition using Pauli paramagnetic lanthanum nickel (LaNi{sub 5}) alloy both as a catalyst and as a source for the Ni-core. The Ni-core was obtained through oxidative dissociation followed by hydrogen reduction during the catalytic growth of the CNTs. Transmission electron microscopy (TEM), selected area electron diffraction (SAED) and X-ray diffraction (XRD) analyses reveal that the Ni-core exists as a face centered cubic single crystal. The magnetic hysteresis loop of Ni/CNTs particle shows increased coercivity (446.42 Oe) than bulk Ni at room temperature. Furthermore, the Ni/CNTs core/shell particles were investigated as anode materials in lithium-ion batteries. The Ni/CNTs electrode delivered a high discharge capacity of 309 mA h g{sup −1} at 0.2 C, and a stable cycle-life, which is attributed to high structural stability of Ni/CNTs electrode during electrochemical lithium-ion insertion and de-insertion redox reactions.

  12. Integrated core-log petrofacies analysis in the construction of a reservoir geomodel: A case study of a mature Mississippian carbonate reservoir using limited data

    USGS Publications Warehouse

    Bhattacharya, S.; Doveton, J.H.; Carr, T.R.; Guy, W.R.; Gerlach, P.M.

    2005-01-01

    Small independent operators produce most of the Mississippian carbonate fields in the United States mid-continent, where a lack of integrated characterization studies precludes maximization of hydrocarbon recovery. This study uses integrative techniques to leverage extant data in an Osagian and Meramecian (Mississippian) cherty carbonate reservoir in Kansas. Available data include petrophysical logs of varying vintages, limited number of cores, and production histories from each well. A consistent set of assumptions were used to extract well-level porosity and initial saturations, from logs of different types and vintages, to build a geomodel. Lacking regularly recorded well shut-in pressures, an iterative technique, based on material balance formulations, was used to estimate average reservoir-pressure decline that matched available drillstem test data and validated log-analysis assumptions. Core plugs representing the principal reservoir petrofacies provide critical inputs for characterization and simulation studies. However, assigning plugs among multiple reservoir petrofacies is difficult in complex (carbonate) reservoirs. In a bottom-up approach, raw capillary pressure (Pc) data were plotted on the Super-Pickett plot, and log- and core-derived saturation-height distributions were reconciled to group plugs by facies, to identify core plugs representative of the principal reservoir facies, and to discriminate facies in the logged interval. Pc data from representative core plugs were used for effective pay evaluation to estimate water cut from completions, in infill and producing wells, and guide-selective perforations for economic exploitation of mature fields. The results from this study were used to drill 22 infill wells. Techniques demonstrated here can be applied in other fields and reservoirs. Copyright ?? 2005. The American Association of Petroleum Geologists. All rights reserved.

  13. Validation and application of a core set of patient-relevant outcome domains to assess the effectiveness of multimodal pain therapy (VAPAIN): a study protocol

    PubMed Central

    Kaiser, Ulrike; Kopkow, Christian; Deckert, Stefanie; Sabatowski, Rainer; Schmitt, Jochen

    2015-01-01

    Introduction Multimodal pain therapy (MPT) has been established accounting for biopsychosocial consideration in diagnostic and therapy. MPT seems to be effective, but comparability of studies is limited due to diversity of study designs and outcome measurements. The presented study aims to develop a core outcome set consisting of a minimum of outcome measures deemed necessary for medical and therapeutic decision-making, which must be measured in all clinical trials and non-randomised intervention studies. Methods and analysis The study consists of several parts. First, the development and recommendation of preliminary core outcome domains will be based on results of a systematic review and structured online surveys. Participants of the expert panel are representatives of methodological, medical, physiotherapeutic, psychotherapeutic profession and patients suffering from chronic pain (n=25). Subsequently, candidate instruments to measure preliminary core outcome domains will be recommended by these experts. Therefore, systematic reviews on measurement properties of preliminary outcome measures will be conducted and finalised in a consensus meeting. Consented instruments and lacking psychometric properties of relevant instruments will be addressed and validated in the following part, a prospective multicentre study in multimodal pain centres on approximately 300 patients with chronic pain. Based on all previous results, a core outcome set for MPT measured in effectiveness studies and daily recordkeeping will be finalised by consensus. Statistical analyses will be performed according to methodological standards (COSMIN). Ethics and dissemination The methods and procedure of the study are developed in compliance with the ethical principles of the Helsinki Declaration and Good Epidemiologic Practice. Recruitment of study participants will require approval of the study by the responsible ethics committee and signed informed consent from each participant. Pseudonymised

  14. Dynamic studies of {sup 11}Li and its core {sup 9}Li on {sup 208}Pb near the Coulomb barrier

    SciTech Connect

    Cubero, M.; Borge, M. J. G.; Alcorta, M.; Madurga, M.; Tengblad, O.; Acosta, L.; Martel, I.; Sanchez-Benitez, A. M.; Alvarez, M. A. G.; Gomez-Camacho, J.; Diget, C.; Galaviz, D.; Fernandez-Garcia, J. P.; Lay, J. A.; Moro, A. M.; Mukha, I.; Shotter, A.; Walden, P.

    2010-04-26

    We measured the scattering of the halo nucleus {sup 11}Li and its core {sup 9}Li on the lead target at TRIUMF at energies below and around to the Coulomb barrier. We report here on our preliminary analysis of the inclusive breakup reaction.

  15. The Seneca Babcock Business Plan: A Case Study in Using Service Learning to Meet the AICPA Core Competencies

    ERIC Educational Resources Information Center

    Tschopp, Daniel J.

    2004-01-01

    In this article, the author explains the trend toward service learning projects in higher education and justifies their use in the field of accounting. He describes a service learning project that was used to directly address the development of the competencies listed in the Core Competency Framework created by the American Institute of Certified…

  16. Studies on polymer nanofibre membranes with optimized core-shell structure as outstanding performance skeleton materials in gel polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Bi, Haitao; Sui, Gang; Yang, Xiaoping

    2014-12-01

    The polyporous polymer nanofibre membranes with optimized core (polyacrylonitrile, PAN)-shell (polymethylmethacrylate, PMMA) structure are prepared by coaxial electrospinning, and then converted to gel polymer electrolytes (GPEs) after the activation process of stacked nanofibre membranes in liquid electrolyte. Based on the proper collocation of polymer materials, the desirable microstructure of polymer membranes as well as the affinity between fibre shell and the electrode/electrolyte result in a high saturated electrolyte uptake and conservation rate. The electrochemical testing results of the GPEs indicate high ionic conductivities, good electrochemical stability and appropriate lithium-ion transference numbers, which are realized through choosing optimal core-shell flow rate ratio. Furthermore, the interface impedance performance of the GPEs shows good stability and compatibility with lithium electrode, which is beneficial for long-term storage and use of the lithium-ion battery. The Li/GPE/LiCoO2 cells with GPEs based on the electrospun membranes with optimized core-shell structure present excellent cycle performance compared to the cell involved with GPEs based on PAN and commercial Celgard 2500. Thus, the polymer membranes consisting of nanofibres with well-designed core-shell structure can be used as a new type of skeleton material in GPEs used in lithium-ion batteries.

  17. Enacting Common Core Instruction: A Comparative Study of the Use of LDC Literacy Tools in Three Sites

    ERIC Educational Resources Information Center

    Beaver, Jessica K.; Reumann-Moore, Rebecca

    2014-01-01

    As of the writing of this report, the Common Core State Standards (CCSS) are being implemented in 45 states and the District of Columbia. Approaches to implementing the standards, however, are highly varied. For the past 3 years, Research For Action (RFA) has been tracking how one approach to implementing the literacy standards--the Literacy…

  18. In Opposition to Core Curriculum. Alternative Models for Undergraduate Education. Contributions to the Study of Education, Number 4.

    ERIC Educational Resources Information Center

    Hall, James W., Ed.; Kevles, Barbara L., Ed.

    In response to some educators' advocacy of a return to a "core curriculum" (a specific set of courses required by all degree-bound college students), this book maintains that the simple acquisition of broad-based knowledge is not the solution to the complex and difficult problems in higher education today. It presents views of the "educated…

  19. Parameter Sensitivity Study of the Unreacted-Core Shrinking Model: A Computer Activity for Chemical Reaction Engineering Courses

    ERIC Educational Resources Information Center

    Tudela, Ignacio; Bonete, Pedro; Fullana, Andres; Conesa, Juan Antonio

    2011-01-01

    The unreacted-core shrinking (UCS) model is employed to characterize fluid-particle reactions that are important in industry and research. An approach to understand the UCS model by numerical methods is presented, which helps the visualization of the influence of the variables that control the overall heterogeneous process. Use of this approach in…

  20. DUST CONTINUUM AND POLARIZATION FROM ENVELOPE TO CORES IN STAR FORMATION: A CASE STUDY IN THE W51 NORTH REGION

    SciTech Connect

    Tang, Ya-Wen; Guilloteau, Stephane; Dutrey, Anne; Ho, Paul T. P.; Koch, Patrick M.

    2013-02-15

    We present the first high-angular resolution (up to 0.''7, {approx}5000 AU) polarization and thermal dust continuum images toward the massive star-forming region W51 North. The observations were carried out with the Submillimeter Array (SMA) in both the subcompact (SMA-SubC) and extended (SMA-Ext) configurations at a wavelength of 870 {mu}m. W51 North is resolved into four cores (SMA1 to SMA4) in the 870 {mu}m continuum image. The associated dust polarization exhibits more complex structures than seen at lower angular resolution. We analyze the inferred morphologies of the plane-of-sky magnetic field (B ) in the SMA1 to SMA4 cores and in the envelope using the SMA-Ext and SMA-SubC data. These results are compared with the B archive images obtained from the Caltech Submillimeter Observatory (CSO) and James Clerk Maxwell Telescope (JCMT). The polarization percentage is about 1% to 4%, and it is found to decrease with higher intensity in our SMA images, which is a similar trend to that previously reported in the CSO and JCMT data. A correlation between dust intensity gradient position angles ({phi}{sub {nabla}I}) and magnetic field position angles ({phi}{sub B}) is found in the CSO, JCMT, and both SMA data sets. This correlation is further analyzed quantitatively. A systematically tighter correlation between {phi}{sub {nabla}I} and {phi}{sub B} is found in the cores, whereas the correlation decreases in outside-core regions. Magnetic field-to-gravity force ratio ({Sigma}{sub B}) maps are derived using the newly developed polarization-intensity gradient method by Koch et al. We find that the force ratios tend to be small ({Sigma}{sub B} {approx}< 0.5) in the cores in all four data sets. In regions outside of the cores, the ratios increase or the field is even dominating gravity ({Sigma}{sub B} > 1). This possibly provides a physical explanation of the tightening correlation between {phi}{sub {nabla}I} and {phi}{sub B} in the cores: The more the B field lines are

  1. Clinical evaluation of carbon fiber reinforced carbon endodontic post, glass fiber reinforced post with cast post and core: A one year comparative clinical study

    PubMed Central

    Preethi, GA; Kala, M

    2008-01-01

    Aim: Restoring endodontically treated teeth is one of the major treatments provided by the dental practitioner. Selection and proper use of restorative materials continues to be a source of frustration for many clinicians. There is controversy surrounding the most suitable choice of restorative material and the placement method that will result in the highest probability of successful treatment. This clinical study compares two different varieties of fiber posts and one cast post and core in terms of mobility of crown margin under finger pressure, recurrent caries detected at the crown margin, fracture of the restoration, fracture of the root and periapical and periodontal pathology requiring crown removal over the period of 12months as evaluated by clinical and radiographical examination. Materials and Methods: 30 root canal treated, single rooted maxillary anterior teeth of 25 patients in the age range of 18–60 years where a post retained crown was indicated were selected for the study between January 2007 and August 2007; and prepared in a standard clinical manner. It was divided into 3 groups of 10 teeth in each group. After post space preparation, the Carbon fiber and Glass fiber reinforced posts were cemented with Scotch bond multipurpose plus bonding agent and RelyX adhesive resin cement in the first and second groups respectively. The Cast post and cores were cemented with Zinc Phosphate cement in the third group. Following post- cementation, the preparation was further refined and a rubber base impression was taken for metal-ceramic crowns which was cemented with Zinc Phosphate cement. A baseline periapical radiograph was taken once each crown was cemented. All patients were evaluated after one week (baseline), 3 months, 6 months and one year for following characteristics mobility of crown margin under finger pressure, recurrent caries detected at the crown margin, fracture of the restoration, fracture of the root and periapical and periodontal pathology

  2. Comparative study on a core-offset fiber temperature sensor between the faraday rotation mirror structure and the double coupling structure

    NASA Astrophysics Data System (ADS)

    Wang, Fang; Zhu, Han; Li, Yunpeng; Zhao, Huihui; Wang, Xu; Liu, Yufang

    2016-05-01

    A temperature sensor based on core-offset single mode fiber (SMF) and a Faraday rotation mirror (FRM) has been proposed and experimentally demonstrated in this paper. This sensor was fabricated by splicing in a section of SMF between two SMFs with a core-offset at two splicing joints. The end of the joint is connected to the FRM, which can double the sensitivity and improve the polarization state stabilization at the sensor output. The variation of the transmission spectrum of the sensor with respect to the surrounding temperature has been experimentally studied. A comparison is made between this design and a laser temperature sensor made of the same core-offset fiber utilizing a double coupling (DC) structure. The results show that, within the range of 1539.42-1553.90 nm, the sensitivity of the proposed sensor is 0.89039 nm/°C and in the range of 47-63 °C. Additionally, the power attenuation is 2.257 dB/°C. The temperature sensitivity in the SMF and FRM sensor is increased by an order of magnitude in comparison with the DC sensor. The instability and low sensitivity characteristics of a laser temperature sensor constructed with DC structure can be solved through the use of core-offset SMF and FRM.

  3. A Comparative in Vitro Study of Apical Microleakage with Five Obturation Techniques: Lateral Condensation, Soft-Core®, Obtura II®, Guttaflow® and Resilon®

    PubMed Central

    Pallarés, Antonio; Cabanillas, Cristina; Zarzosa, Ignacio; Victoria, Alejandro

    2014-01-01

    Aim A comparison was made between the root canal lateral condensation technique and other condensation techniques in which physical (temperature: Soft-Core®, Obtura II®) or chemical changes (condensation: Guttaflow®, Resilon®) may affect the dimensional stability of obturation and thus favor apical microleakage. Materials and methods A total of 212 single-root teeth removed for orthodontic or periodontal reasons were randomized to 5 groups of 40 teeth each. Six samples were used as positive controls, and another 6 as negative controls. The teeth were worked with the Hero 642 system, and each group was obturated using a different technique: lateral condensation, Obtura II®, Soft-Core®, Guttaflow® or Resilon®. The samples were immersed in black ink, and after 72 hours the teeth were transparentized using the technique described by Robertson. Filtration of the ink was measured under the stereoscopic microscope. Analysis of variance and post-hoc testing were used for the statistical analysis. Results The Soft-Core® obturated group showed significantly greater microleakage than the other groups, with no differences among the rest of the groups. Conclusions Under the conditions of this study, the teeth obturated with the Soft-Core® technique showed greater apical microleakage than the other systems.

  4. Two-Dimensional Cutting (TDC) Vitrectome: In Vitro Flow Assessment and Prospective Clinical Study Evaluating Core Vitrectomy Efficiency versus Standard Vitrectome

    PubMed Central

    2016-01-01

    Purpose. To evaluate comparative aspiration flow performance and also vitrectomy operating time efficiency using a double-cutting open port vitreous cutting system incorporated in a two-dimensional cutting (TDC, DORC International) vitrectome design versus standard vitreous cutter. Methods. In vitro investigations compared aspiration flow rates in artificial vitreous humor at varying cutter speeds and vacuum levels using a TDC vitrectome and a standard vitrectome across different aspiration pump systems. A prospective single-centre clinical study evaluated duration of core vitrectomy in 80 patients with macular pucker undergoing 25-gauge or 27-gauge vitrectomy using either a TDC vitrectome at 16,000 cuts per minute (cpm) or standard single-cut vitrectome, combined with a Valve Timing intelligence (VTi) pump system (EVA, DORC International). Results. Aspiration flow rates remained constant independent of TDC vitrectome cut rate, while flow rates decreased linearly at higher cutter speeds using a classic single-blade vitrectome. Mean duration of core vitrectomy surgeries using a TDC vitreous cutter system was significantly (p < 0.001) shorter than the mean duration of core vitrectomy procedures using a single-cut vitrectome of the same diameter (reduction range, 34%–50%). Conclusion. Vitrectomy surgery performed using a TDC vitrectome was faster than core vitrectomy utilizing a standard single-action vitrectome at similar cut speeds. PMID:27190635

  5. Exploring the structural and magnetic properties of TiO{sub 2}/SnO{sub 2} core/shell nanocomposite: An experimental and density functional study

    SciTech Connect

    Chetri, Pawan; Basyach, Priyanka; Choudhury, Amarjyoti

    2014-12-15

    TiO{sub 2}/SnO{sub 2} core/shell nanocomposite is prepared via a simple sol–gel method and the properties are compared with the individual TiO{sub 2} (core) and SnO{sub 2} (shell). The corresponding characterizations are carried out in terms of structural and magnetic properties of TiO{sub 2}/SnO{sub 2}, TiO{sub 2} and SnO{sub 2} nanosystems. Structural properties are studied via XRD, TEM, Raman spectroscopy, FTIR and XPS. Magnetic characterization is performed by measuring Moment vs. Applied Field for all the samples and Moment vs. Temperature for TiO{sub 2}/SnO{sub 2} core/shell nanocomposite. We also went for a better insight with the help of theoretical measures. First principle calculations have been executed using “Density Functional Theory” (DFT)-based MedeA VASP package to compare the results of TiO{sub 2}/SnO{sub 2} with TiO{sub 2} (1 1 0) and SnO{sub 2} (1 1 0) surface calculations and its effect on the magnetic nature of the specific nanoparticles. XRD, RAMAN and FTIR gave indirect evidence of formation of core shell nanostructure while TEM micrographs provide the direct evidence of formation of core shell nanostructure. The magnetic study shows a higher saturation magnetization for the core/shell nanostructure compared to pristine TiO{sub 2} and SnO{sub 2}. In this report, we have attempted to relate this experimental observation with the results of the first principle calculations. - Graphical abstract: Above pictorial presentation (from left) represents the model for TS, TiO{sub 2} and SnO{sub 2} used for DFT calculation and the obtained magnetic results for all the prepared systems. - Highlights: • Synthesis of TiO{sub 2}/SnO{sub 2} core/shell nanocomposites by a simple sol–gel technique. • The nanocomposites show better magnetic property than pristine nanoparticles. • DFT based calculations also support the experimental evidences.

  6. Dual-core antiresonant hollow core fibers.

    PubMed

    Liu, Xuesong; Fan, Zhongwei; Shi, Zhaohui; Ma, Yunfeng; Yu, Jin; Zhang, Jing

    2016-07-25

    In this work, dual-core antiresonant hollow core fibers (AR-HCFs) are numerically demonstrated, based on our knowledge, for the first time. Two fiber structures are proposed. One is a composite of two single-core nested nodeless AR-HCFs, exhibiting low confinement loss and a circular mode profile in each core. The other has a relatively simple structure, with a whole elliptical outer jacket, presenting a uniform and wide transmission band. The modal couplings of the dual-core AR-HCFs rely on a unique mechanism that transfers power through the air. The core separation and the gap between the two cores influence the modal coupling strength. With proper designs, both of the dual-core fibers can have low phase birefringence and short modal coupling lengths of several centimeters.

  7. Time resolved photoluminescence study of CdSe/CdMnS/CdS core/shell/shell nanoplatelets heterostructures

    NASA Astrophysics Data System (ADS)

    Scrace, Thomas; Delikanli, Savas; Akgul, Mehmet Zafer; Murphy, Joseph; Thomay, Tim; Zhang, Peiyao; Norden, Tenzin; Cartwright, Alexander; Petrou, Athos; Demir, Hilmi Volkan

    We have recorded the time evolution of the photoluminescence (PL) for CdSe/CdMnS/CdS core/shell/shell solution-processed nanoplatelets (NP) using ultrafast pulses at 400 nm and 514 nm. Our NPs consist of a core with 5 monolayers (1.5 nm) of CdSe and average lateral dimensions of 55 x 10 nm2. Using 400 nm pulses we excite electron-hole pairs above the CdS shell bandgap; with 514 nm pulses we excite only in the CdSe core. The holes are primarily localized in the CdSe core, while the electrons are delocalized. Our measurements show that at Δt = 0, the peak PL energy for both kind of excitations is the same. As a function of time, both types of excitations result in a red-shift. The red shift of with 400 nm excitation is 60 meV and is described by two time scales: τ1 = 270 ps and τ2 = 2.5 ns. The red shift with the 514 nm excitation is 30 meV and is described by a single time scale: τ2' = 2.5 ns. These results are discussed in terms of dipole layer formation. H.V.D. is supported by EU-FP7 Nanophotonics4Energy NoE, and TUBITAK EEEAG 109E002, 109E004, NRF-RF-2009-09, NRF-CRP-6-2010-02 and A*STAR of Singapore. A.P. is supported by NSF DMR 1305770.

  8. Dielectric and electro-optic studies of a bimesogenic liquid crystal composed of bent-core and calamitic units.

    PubMed

    Balachandran, R; Panov, V P; Vij, J K; Shanker, G; Tschierske, C; Merkel, K; Kocot, A

    2014-09-01

    A bimesogen, BR1, composed of a bent-core and calamitic unit, linked laterally via a flexible spacer is investigated by dielectric and electro-optic techniques. X-ray results show the presence of clusters in the nematic phase, and the cluster size is of the order of the thickness of a single layer. The splitting of the small-angle scattering Δχ/2 is about 50°, which indicates SmC like clusters with a significant tilt of the molecules in the quasilayers. The sign reversal of the dielectric anisotropy Δε' is observed as a function of frequency; the behavior is rather similar to that exhibited by the conventional dual frequency nematics, composed of a calamitic mesogen, with the exception that it occurs at much lower frequencies in this material. Interestingly, as the bimesogen enters its nematic phase, the average permittivity decreases as the temperature is lowered. This indicates the onset of antiparallel association of some of the dipoles in the system, and this type of association is much more prominent in BR1 in comparison to other bent-core liquid crystalline systems composed of the same bisbenzoate core unit. The analysis of the dielectric spectra using the Maier-Meier model confirms the onset of an antiparallel correlation of dipoles occurring at the isotropic to nematic phase transition temperature. Additionally these results support a model of the cluster where the transverse dipole moments in the neighboring layers are antiparalleled to each other.

  9. Verification study of thorium cross section in MVP calculation of thorium based fuel core using experimental data

    SciTech Connect

    Mai, V. T.; Fujii, T.; Wada, K.; Kitada, T.; Takaki, N.; Yamaguchi, A.; Watanabe, H.; Unesaki, H.

    2012-07-01

    Considering the importance of thorium data and concerning about the accuracy of Th-232 cross section library, a series of experiments of thorium critical core carried out at KUCA facility of Kyoto Univ. Research Reactor Inst. have been analyzed. The core was composed of pure thorium plates and 93% enriched uranium plates, solid polyethylene moderator with hydro to U-235 ratio of 140 and Th-232 to U-235 ratio of 15.2. Calculations of the effective multiplication factor, control rod worth, reactivity worth of Th plates have been conducted by MVP code using JENDL-4.0 library [1]. At the experiment site, after achieving the critical state with 51 fuel rods inserted inside the reactor, the measurements of the reactivity worth of control rod and thorium sample are carried out. By comparing with the experimental data, the calculation overestimates the effective multiplication factor about 0.90%. Reactivity worth of the control rods evaluation using MVP is acceptable with the maximum discrepancy about the statistical error of the measured data. The calculated results agree to the measurement ones within the difference range of 3.1% for the reactivity worth of one Th plate. From this investigation, further experiments and research on Th-232 cross section library need to be conducted to provide more reliable data for thorium based fuel core design and safety calculation. (authors)

  10. Rational syntheses of core-shell Fex@Pt nanoparticles for the study of electrocatalytic oxygen reduction reaction

    PubMed Central

    Jang, Ji-Hoon; Lee, Eunjik; Park, Jinwoo; Kim, Gunn; Hong, Suklyun; Kwon, Young-Uk

    2013-01-01

    We report on the syntheses of core-shell Fex@Pt (x = 0.4–1.2) nanoparticles (NPs) with Pt-shell thickness systematically controlled while the overall particle size is constant. The syntheses were achieved via one-pot ultrasound-assisted polyol synthesis (UPS) reactions. Fe1.2@Pt showed a record-breaking high core-element content (55 at%) of core-shell NPs. Based on observations from a series of control experiments, we propose a mechanism of the NPs' formation that enables control of shell thickness in UPS reactions. Fex@Pt NPs showed drastic enhancements in mass and specific activity for oxygen reduction reaction (ORR) and significantly enhanced durability compared to commercial Pt NPs. Fex@Pt with a 1 (monolayer) ML Pt shell showed the highest activity. The ab initio density functional theory calculations on the binding energies of oxygen species on the surfaces of Fex@Pt NPs showed that the 1 ML case is most favourable for the ORR, and in good agreement with the experimental results. PMID:24096587

  11. Dielectric and electro-optic studies of a bimesogenic liquid crystal composed of bent-core and calamitic units

    NASA Astrophysics Data System (ADS)

    Balachandran, R.; Panov, V. P.; Vij, J. K.; Shanker, G.; Tschierske, C.; Merkel, K.; Kocot, A.

    2014-09-01

    A bimesogen, BR1, composed of a bent-core and calamitic unit, linked laterally via a flexible spacer is investigated by dielectric and electro-optic techniques. X-ray results show the presence of clusters in the nematic phase, and the cluster size is of the order of the thickness of a single layer. The splitting of the small-angle scattering Δχ/2/ is about 50°, which indicates SmC like clusters with a significant tilt of the molecules in the quasilayers. The sign reversal of the dielectric anisotropy Δɛ' is observed as a function of frequency; the behavior is rather similar to that exhibited by the conventional dual frequency nematics, composed of a calamitic mesogen, with the exception that it occurs at much lower frequencies in this material. Interestingly, as the bimesogen enters its nematic phase, the average permittivity decreases as the temperature is lowered. This indicates the onset of antiparallel association of some of the dipoles in the system, and this type of association is much more prominent in BR1 in comparison to other bent-core liquid crystalline systems composed of the same bisbenzoate core unit. The analysis of the dielectric spectra using the Maier-Meier model confirms the onset of an antiparallel correlation of dipoles occurring at the isotropic to nematic phase transition temperature. Additionally these results support a model of the cluster where the transverse dipole moments in the neighboring layers are antiparalleled to each other.

  12. Dielectric and electro-optic studies of a bimesogenic liquid crystal composed of bent-core and calamitic units.

    PubMed

    Balachandran, R; Panov, V P; Vij, J K; Shanker, G; Tschierske, C; Merkel, K; Kocot, A

    2014-09-01

    A bimesogen, BR1, composed of a bent-core and calamitic unit, linked laterally via a flexible spacer is investigated by dielectric and electro-optic techniques. X-ray results show the presence of clusters in the nematic phase, and the cluster size is of the order of the thickness of a single layer. The splitting of the small-angle scattering Δχ/2 is about 50°, which indicates SmC like clusters with a significant tilt of the molecules in the quasilayers. The sign reversal of the dielectric anisotropy Δε' is observed as a function of frequency; the behavior is rather similar to that exhibited by the conventional dual frequency nematics, composed of a calamitic mesogen, with the exception that it occurs at much lower frequencies in this material. Interestingly, as the bimesogen enters its nematic phase, the average permittivity decreases as the temperature is lowered. This indicates the onset of antiparallel association of some of the dipoles in the system, and this type of association is much more prominent in BR1 in comparison to other bent-core liquid crystalline systems composed of the same bisbenzoate core unit. The analysis of the dielectric spectra using the Maier-Meier model confirms the onset of an antiparallel correlation of dipoles occurring at the isotropic to nematic phase transition temperature. Additionally these results support a model of the cluster where the transverse dipole moments in the neighboring layers are antiparalleled to each other. PMID:25314464

  13. A novel approach to arthritis treatment based on resveratrol and curcumin co-encapsulated in lipid-core nanocapsules: In vivo studies.

    PubMed

    Coradini, Karine; Friedrich, Rossana B; Fonseca, Francisco N; Vencato, Marina S; Andrade, Diego F; Oliveira, Cláudia M; Battistel, Ana Paula; Guterres, Silvia S; da Rocha, Maria Izabel U M; Pohlmann, Adriana R; Beck, Ruy C R

    2015-10-12

    Resveratrol and curcumin are two natural polyphenols extensively used due to their remarkable anti-inflammatory activity. The present work presents an inedited study of the in vivo antioedematogenic activity of these polyphenols co-encapsulated in lipid-core nanocapsules on Complete Freund's adjuvant (CFA)-induced arthritis in rats. Lipid-core nanocapsules were prepared by interfacial deposition of preformed polymer. Animals received a single subplantar injection of CFA in the right paw. Fourteen days after arthritis induction, they were treated with resveratrol, curcumin, or both in solution or loaded in lipid-core nanocapsules (1.75 mg/kg/twice daily, i.p.), for 8 days. At the doses used, the polyphenols in solution were not able to decrease paw oedema. However, nanoencapsulation improved the antioedematogenic activity of polyphenols at the same doses. In addition, the treatment with co-encapsulated polyphenols showed the most pronounced effects, where an inhibition of 37-55% was observed between day 16 and 22 after arthritis induction. This treatment minimized most of the histological changes observed, like fibrosis in synovial tissue, cartilage and bone loss. In addition, unlike conventionally arthritis treatment, resveratrol and curcumin co-encapsulated in lipid-core nanocapsules did not alter important hepatic biochemical markers (ALP, AST, and ALT). In conclusion, the strategy of co-encapsulating resveratrol and curcumin in lipid-core nanocapsules improves their efficacy as oedematogenic agents, with no evidence of hepatotoxic effects. This is a promising strategy for the development of new schemes for treatment of chronic inflammation diseases, like arthritis. PMID:26206297

  14. Anisotropic charged core envelope star

    NASA Astrophysics Data System (ADS)

    Mafa Takisa, P.; Maharaj, S. D.

    2016-08-01

    We study a charged compact object with anisotropic pressures in a core envelope setting. The equation of state is quadratic in the core and linear in the envelope. There is smooth matching between the three regions: the core, envelope and the Reissner-Nordström exterior. We show that the presence of the electric field affects the masses, radii and compactification factors of stellar objects with values which are in agreement with previous studies. We investigate in particular the effect of electric field on the physical features of the pulsar PSR J1614-2230 in the core envelope model. The gravitational potentials and the matter variables are well behaved within the stellar object. We demonstrate that the radius of the core and the envelope can vary by changing the parameters in the speed of sound.

  15. The effect of core suture flexor tendon repair techniques on gliding resistance during static cycle motion and load to failure: a human cadaver study

    PubMed Central

    Moriya, T.; Larson, M. C.; Zhao, C.; An, K.-N.; Amadio, P. C.

    2011-01-01

    The purpose of this study was to describe a modification of the Massachusetts General Hospital (MMGH) tendon repair and to compare it with three other suture techniques. Twenty human flexor digitorum profundus (FDP) tendons were randomly assigned to the modified Pennington (MP) suture and the MMGH suture. These were compared to the modified Kessler (MK) and Massachusetts General Hospital (MGH) sutures, using data from a previous study. All tendons were repaired with a similar epitendinous stitch and core sutures of 4-0 FiberWire. There was no significant difference in the normalized gliding resistance within the two-strand or four-strand core repair groups. The MP suture had significantly higher 2 mm gap force and ultimate load to failure than the MK suture. The MMGH suture had significantly higher 2 mm gap force and maximum failure ultimate load than the MGH suture. All repairs failed by knot unravelling. PMID:21987278

  16. Summary final report: Contract between the Japan atomic power company and the U.S. Department of Energy Improvement of core safety - study on GEM (III)

    SciTech Connect

    Burke, T.M.; Lucoff, D.M.

    1997-03-18

    This report provides a summary of activities associated with the technical exchange between representatives of the Japan Atomic Power Company (JAPC) and the United States Department of Energy (DOE) regarding the development and testing of Gas Expansion Modules (GEM) at the Fast Flux Test Facility (FFTF). Issuance of this report completes the scope of work defined in the original contract between JAPC and DOE titled ''Study on Improvement of Core Safety - Study on GEM (III).'' Negotiations related to potential modification of the contract are in progress. Under the proposed contract modification, DOE would provide an additional report documenting FFTF pump start tests with GEMs and answer additional JAPC questions related to core safety with and without GEMs.

  17. A bimodal neurophysiological study of motor control in attention-deficit hyperactivity disorder: a step towards core mechanisms?

    PubMed

    Heinrich, Hartmut; Hoegl, Thomas; Moll, Gunther H; Kratz, Oliver

    2014-04-01

    Knowledge about the core neural mechanisms of attention-deficit hyperactivity disorder, a pathophysiologically heterogeneous psychiatric disorder starting in childhood, is still limited. Progress may be achieved by combining different methods and levels of investigation. In the present study, we investigated neural mechanisms of motor control in 19 children with attention-deficit hyperactivity disorder (aged 9-14 years) and 21 age-matched typically developing children by relating neural markers of attention and response control (using event-related potentials) and measures of motor excitability/inhibition (evoked by transcranial magnetic stimulation). Thus, an interplay of processes at a subsecond scale could be studied. Using a monetary incentives-based cued Go/No-Go task, parameters that are well-known to be reduced in attention-deficit hyperactivity disorder were analysed: event-related potential components P3 (following cue stimuli; in Go and No-Go trials) and contingent negative variation as well as the transcranial magnetic stimulation-based short-interval intracortical inhibition measured at different latencies in Go and No-Go trials. For patient and control groups, different associations were obtained between performance, event-related potential and transcranial magnetic stimulation measures. In children with attention-deficit hyperactivity disorder, the P3 amplitude in Go trials was not correlated with reaction time measures but with short-interval intracortical inhibition at rest (r=0.56, P=0.01). In No-Go trials, P3 and short-interval intracortical inhibition after inhibiting the response (at 500 ms post-stimulus) were correlated in these children only (r=0.62; P=0.008). A classification rate of 90% was achieved when using short-interval intracortical inhibition (measured shortly before the occurrence of a Go or No-Go stimulus) and the amplitude of the P3 in cue trials as input features in a linear discriminant analysis. Findings indicate deviant neural

  18. Ab-initio study of the physics and chemistry of metals in planetary core materials and nanomaterials at relevant thermodynamics conditions

    NASA Astrophysics Data System (ADS)

    Alnemrat, Sufian

    Material science investigates the relationship between the structure of materials at the atomic or molecular scales and their macroscopic properties. Ab-initio DFT, atomistic force-field, and molecular dynamic simulations have been used to investigate the electronic, optical, structural, magnetic properties of group II-VI semiconductor nanoparticles, metal organic frameworks, amide-water complexes, and planetary core materials at the atomic and/or molecular level. Structure, density of electronic states, magnetic dipole moments, and HOMO-LUMO gaps of surface-passivated ZnnSem, Cd nTem, CdTe-core/ZnTe-shell, and ZnSe-core/CdSe-shell nanocrystals are calculated using a first principles. The intrinsic magnetic dipole moments are found to be strongly size dependent. The detailed analysis of the dipole moment as a function of particle size shows the appearance of zincblende-wurtzite polymorphism in these nano-particles. Energy-efficient adsorption processes are considered promising alternatives to traditional separation techniques. Mg-MOF-74, a magnesium-based metal organic framework, has been used as an efficient adsorbent structure for several gas separation purposes. Adsorption equilibria and kinetics of ethane, ethylene, propane, and propylene on Mg-MOF-74 were determined at temperatures of 278, 298, and 318 K and pressures up to 100 kPa. A grand canonical Monte Carlo simulation was conducted to calculate the adsorption isotherms and to explore adsorption mechanisms. I found that propylene and propane have a stronger affinity to the Mg-MOF-74 adsorbent than ethane and ethylene because of their significant dipole moments. Ab-initio molecular dynamics simulations were carried out to study the role of equilibrium volume and magnetism in Fe and FeX alloys (X=Ni, O) and their stability at earth core conditions. This study provides new insights into the pressure dependence of magnetism by tracking the hybridization between crystal orbitals for pressures up to 600 GPa in

  19. Lunar Polar Coring Lander

    NASA Technical Reports Server (NTRS)

    Angell, David; Bealmear, David; Benarroche, Patrice; Henry, Alan; Hudson, Raymond; Rivellini, Tommaso; Tolmachoff, Alex

    1990-01-01

    Plans to build a lunar base are presently being studied with a number of considerations. One of the most important considerations is qualifying the presence of water on the Moon. The existence of water on the Moon implies that future lunar settlements may be able to use this resource to produce things such as drinking water and rocket fuel. Due to the very high cost of transporting these materials to the Moon, in situ production could save billions of dollars in operating costs of the lunar base. Scientists have suggested that the polar regions of the Moon may contain some amounts of water ice in the regolith. Six possible mission scenarios are suggested which would allow lunar polar soil samples to be collected for analysis. The options presented are: remote sensing satellite, two unmanned robotic lunar coring missions (one is a sample return and one is a data return only), two combined manned and robotic polar coring missions, and one fully manned core retrieval mission. One of the combined manned and robotic missions has been singled out for detailed analysis. This mission proposes sending at least three unmanned robotic landers to the lunar pole to take core samples as deep as 15 meters. Upon successful completion of the coring operations, a manned mission would be sent to retrieve the samples and perform extensive experiments of the polar region. Man's first step in returning to the Moon is recommended to investigate the issue of lunar polar water. The potential benefits of lunar water more than warrant sending either astronauts, robots or both to the Moon before any permanent facility is constructed.

  20. Cross calibration between XRF and ICP-MS for high spatial resolution analysis of ombrotrophic peat cores for palaeoclimatic studies.

    PubMed

    Poto, Luisa; Gabrieli, Jacopo; Crowhurst, Simon; Agostinelli, Claudio; Spolaor, Andrea; Cairns, Warren R L; Cozzi, Giulio; Barbante, Carlo

    2015-01-01

    Ombrotrophic peatlands are remarkable repositories of high-quality climatic signals because their only source of nutrients is precipitation. Although several analytical techniques are available for analysing inorganic components in peat samples, they generally provide only low-resolution data sets. Here we present a new analytical approach for producing high-resolution data on main and trace elements from ombrotrophic peat cores. Analyses were carried out on a 7-m-long peat core collected from Danta di Cadore, North-Eastern Italy (46° 34' 16″ N, 12° 29' 58″ E). Ca, Ti, Cr, Fe, Cu, Zn, Ga, Sr, Y, Cd, Ba and Pb were detected at a resolution of 2.5 mm with a non-destructive X-ray fluorescence core scanner (XRF-CS). Calibration and quantification of the XRF-CS intensities was obtained using collision reaction cell inductively coupled plasma quadruple mass spectrometry (CRC-ICP-QMS). CRC-ICP-QMS measurements were carried out on discrete samples at a resolution of 1 cm, after dissolution of 150-mg aliquots with 9 ml HNO3 and 1 ml HF at 220 °C in a microwave system. We compare qualitative XRF-CS and quantitative CRC-ICP-MS data and, however the several sources of variability of the data, develop a robust statistical approach to determine the R (2) and the coefficient of a simple regression model together with confidence intervals. Perfect positive correlations were estimated for Cd, Cr, Pb, Sr, Ti and Zn; high positive correlations for Ba (0.8954), Y (0.7378), Fe (0.7349) and Cu (0.7028); while moderate positive correlations for Ga (0.5951) and Ca (0.5435). With our results, we demonstrate that XRF scanning techniques can be used, together with other well-established geochemical techniques (such as ICP-MS), to produce high-resolution (up to 2.5 mm) quantitative data from ombrotrophic peat bog cores.

  1. Study of optical nonlinearity of CdSe and CdSe@ZnO core-shell quantum dots in nanosecond regime

    NASA Astrophysics Data System (ADS)

    Deepika; Dhar, Rakesh; Mohan, Devendra

    2015-12-01

    Thioglycolic acid capped cadmium selenide (CdSe) and CdSe@ZnO core-shell quantum dots have been synthesized in aqueous phase. The sample was characterized by UV-vis spectrophotometer, TEM and Z-scan technique. The nonlinear optical parameters viz. nonlinear absorption coefficient (β), nonlinear refractive index (n2) and third-order nonlinear susceptibilities (χ3) of quantum dots have been estimated using second harmonic of Nd:YAG laser. The study predicts that CdSe@ZnO quantum dots exhibits strong nonlinearity as compared to core CdSe quantum dots. The nonlinearity in quantum dots is attributed to the presence of resonant excitation and free optical processes. The presence of RSA in these nanoparticles makes them a potential material for the development of optical limiter.

  2. [Clinical study on total intravenous anesthesia with droperidol, fentanyl, and ketamine--18. Effect on peripheral circulation as judged by core-peripheral temperature gradient].

    PubMed

    Ohkawa, H; Iwakawa, T; Ohtomo, N; Kitayama, M; Miyahara, A; Matsuki, A

    1993-04-01

    Effect of total intravenous anesthesia with droperidol, fentanyl and ketamine (DFK) on peripheral circulation was studied by examining core-peripheral temperature gradient in twenty five patients who underwent abdominal surgery. A core temperature probe was attached on the forehead and peripheral probe on the palm of the hand of the side on which the blood pressure cuff was not applied. The temperature gradient was less than three degrees centigrade in 60% of the patients and the gradient was significantly less as compared with that of isoflurane anesthesia even at 300 minutes after the start of surgical operation. This advantage would have been caused by such factors as circulatory stimulating effect of ketamine, sympathetic blocking effect by droperidol and adequate postoperative analgesia by fentanyl and norketamine, a metabolite of ketamine. The results suggest that DFK would exert a beneficial effect on peripheral circulation, particularly during prolonged surgical procedures.

  3. Study of the rhizobacterium Azospirillum brasilense Sp245 using Mössbauer spectroscopy with a high velocity resolution: Implication for the analysis of ferritin-like iron cores

    NASA Astrophysics Data System (ADS)

    Alenkina, I. V.; Oshtrakh, M. I.; Tugarova, A. V.; Biró, B.; Semionkin, V. A.; Kamnev, A. A.

    2014-09-01

    The results of a comparative study of two samples of the rhizobacterium Azospirillum brasilense (strain Sp245) prepared in different conditions and of human liver ferritin using Mössbauer spectroscopy with a high velocity resolution demonstrated the presence of ferritin-like iron (i.e. iron similar to that found in ferritin-like proteins) in the bacterium. Mössbauer spectra of these samples were fitted in two ways: as a rough approximation using a one quadrupole doublet fit (the homogeneous iron core model) and using a superposition of quadrupole doublets (the heterogeneous iron core model). Both results demonstrated differences in the Mössbauer parameters for mammalian ferritin and for bacterial ferritin-like iron. Moreover, some differences in the Mössbauer parameters were observed between the two samples of A. brasilense Sp245 related to the differences in their preparation conditions.

  4. Magnetic field assisted self-assembly of ferrite-ferroelectric core-shell nanofibers and studies on magneto-electric interactions

    SciTech Connect

    Sreenivasulu, G.; Zhang, Ru; Sharma, K.; Janes, C.; Mukundan, A.; Srinivasan, G.; Popov, Maksym

    2014-02-03

    Core-shell nanofibers of nickel ferrite and lead zirconate titanate have been synthesized by electrospinning, assembled into superstructure in uniform or non-uniform magnetic fields, and have been characterized in terms of ferroic order parameters and strain mediated magneto-electric (ME) coupling. The core-shell structure was confirmed by electron microscopy and scanning probe microscopy. Studies on magnetic field induced polarization P in assembled samples showed a decrease or increase in P, depending on the nature of fibers and strengthening of ME coupling with change in remnant-P as high as 32%. Strong ME interactions were evident from H-induced variation in permittivity at 20–22 GHz.

  5. DFT study of Fe-Ni core-shell nanoparticles: Stability, catalytic activity, and interaction with carbon atom for single-walled carbon nanotube growth

    SciTech Connect

    Yang, Zhimin; Wang, Qiang Shan, Xiaoye; Zhu, Hongjun; Li, Wei-qi; Chen, Guang-hui

    2015-02-21

    Metal catalysts play an important role in the nucleation and growth of single-walled carbon nanotubes (SWCNTs). It is essential for probing the nucleation and growth mechanism of SWCNTs to fundamentally understand the properties of the metal catalysts and their interaction with carbon species. In this study, we systematically studied the stability of 13- and 55-atom Fe and Fe-Ni core-shell particles as well as these particles interaction with the carbon atoms using the density functional theory calculations. Icosahedral 13- and 55-atom Fe-Ni core-shell bimetallic particles have higher stability than the corresponding monometallic Fe and Ni particles. Opposite charge transfer (or distribution) in these particles leads to the Fe surface-shell displays a positive charge, while the Ni surface-shell exhibits a negative charge. The opposite charge transfer would induce different chemical activities. Compared with the monometallic Fe and Ni particles, the core-shell bimetallic particles have weaker interaction with C atoms. More importantly, C atoms only prefer staying on the surface of the bimetallic particles. In contrast, C atoms prefer locating into the subsurface of the monometallic particles, which is more likely to form stable metal carbides. The difference of the mono- and bimetallic particles on this issue may result in different nucleation and growth mechanism of SWCNTs. Our findings provide useful insights for the design of bimetallic catalysts and a better understanding nucleation and growth mechanism of SWCNTs.

  6. DFT study of Fe-Ni core-shell nanoparticles: Stability, catalytic activity, and interaction with carbon atom for single-walled carbon nanotube growth

    NASA Astrophysics Data System (ADS)

    Yang, Zhimin; Wang, Qiang; Shan, Xiaoye; Li, Wei-qi; Chen, Guang-hui; Zhu, Hongjun

    2015-02-01

    Metal catalysts play an important role in the nucleation and growth of single-walled carbon nanotubes (SWCNTs). It is essential for probing the nucleation and growth mechanism of SWCNTs to fundamentally understand the properties of the metal catalysts and their interaction with carbon species. In this study, we systematically studied the stability of 13- and 55-atom Fe and Fe-Ni core-shell particles as well as these particles interaction with the carbon atoms using the density functional theory calculations. Icosahedral 13- and 55-atom Fe-Ni core-shell bimetallic particles have higher stability than the corresponding monometallic Fe and Ni particles. Opposite charge transfer (or distribution) in these particles leads to the Fe surface-shell displays a positive charge, while the Ni surface-shell exhibits a negative charge. The opposite charge transfer would induce different chemical activities. Compared with the monometallic Fe and Ni particles, the core-shell bimetallic particles have weaker interaction with C atoms. More importantly, C atoms only prefer staying on the surface of the bimetallic particles. In contrast, C atoms prefer locating into the subsurface of the monometallic particles, which is more likely to form stable metal carbides. The difference of the mono- and bimetallic particles on this issue may result in different nucleation and growth mechanism of SWCNTs. Our findings provide useful insights for the design of bimetallic catalysts and a better understanding nucleation and growth mechanism of SWCNTs.

  7. Study on preparation and microwave absorption property of the core-nanoshell composite materials doped with La.

    PubMed

    Wei, Liqiu; Che, Ruxin; Jiang, Yijun; Yu, Bing

    2013-12-01

    Microwave absorbing material plays a great role in electromagnetic pollution controlling, electromagnetic interference shielding and stealth technology, etc. The core-nanoshell composite materials doped with La were prepared by a solid-state reaction method, which is applied to the electromagnetic wave absorption. The core is magnetic fly-ash hollow cenosphere, and the shell is the nanosized ferrite doped with La. The thermal decomposition process of the sample was investigated by thermogravimetry and differential thermal analysis. The morphology and components of the composite materials were investigated by the X-ray diffraction analysis, the microstructure was observed by scanning electron microscope and transmission electron microscope. The results of vibrating sample magnetometer analysis indicated that the exchange-coupling interaction happens between ferrite of magnetic fly-ash hollow cenosphere and nanosized ferrite coating, which caused outstanding magnetic properties. The microwave absorbing property of the sample was measured by reflectivity far field radar cross section of radar microwave absorbing material with vector network analyzer. The results indicated that the exchange-coupling interaction enhanced magnetic loss of composite materials. Therefore, in the frequency of 5 GHz, the reflection coefficient can achieve -24 dB. It is better than single material and is consistent with requirements of the microwave absorbing material at the low-frequency absorption. PMID:25078834

  8. Core-shell Rh-Pt nanocubes: A model for studying compressive strain effects in bimetallic nanocatalysts

    NASA Astrophysics Data System (ADS)

    Harak, Ethan William

    Shape-controlled bimetallic nanocatalysts often have increased activities and stabilities over their monometallic counterparts due to surface strain effects and electron transfer between the two metals. Here, we demonstrate that the degree of surface strain can be manipulated in shape-controlled nanocrystals through a bimetallic core shell architecture. This ability is achieved in a model core shell Rh Pt nanocube system through control of shell thickness. An increase in the Pt shell thickness leads to more compressive strain, which can increase the Pt 4f7/2 binding energy by as much as 0.13 eV. This change in electronic structure is correlated with a weakening of surface-adsorbate interactions, which we exploit to reduce catalyst poisoning by CO during formic acid electrooxidation. In fact, by precisely controlling the Pt shell thickness, the maximum current density achieved with Rh Pt nanocubes was 3.5 times greater than that achieved with similarly sized Pt nanocubes, with decreased CO generation as well. This system serves as a model for how bimetallic architectures can be used to manipulate the electronic structure of nanoparticle surfaces for efficient catalysis. The strategy employed here should enable the performance of bimetallic nanomaterials comprised of more cost-effective metals to be enhanced as well.

  9. Study of iron dimers reveals angular dependence of valence-to-core X-ray emission spectra.

    PubMed

    Pollock, Christopher J; Lancaster, Kyle M; Finkelstein, Kenneth D; DeBeer, Serena

    2014-10-01

    Transition-metal Kβ X-ray emission spectroscopy (XES) is a developing technique that probes the occupied molecular orbitals of a metal complex. As an element-specific probe of metal centers, Kβ XES is finding increasing applications in catalytic and, in particular, bioinorganic systems. For the continued development of XES as a probe of these complex systems, however, the full range of factors which contribute to XES spectral modulations must be explored. In this report, an investigation of a series of oxo-bridged iron dimers reveals that the intensity of valence-to-core features is sensitive to the Fe-O-Fe bond angle. The intensity of these features has a well-known dependence on metal-ligand bond distance, but a dependence upon bond angle has not previously been documented. Herein, we explore the angular dependence of valence-to-core XES features both experimentally and computationally. Taken together, these results show that, as the Fe-O-Fe angle decreases, the intensity of the Kβ″ feature increases and that this effect is modulated by increasing amounts of Fe np mixing into the O 2s orbital at smaller bond angles. The relevance of these findings to the identification of oxygenated intermediates in bioinorganic systems is highlighted, with special emphasis given to the case of soluble methane monooxygenase.

  10. Study on preparation and microwave absorption property of the core-nanoshell composite materials doped with La.

    PubMed

    Wei, Liqiu; Che, Ruxin; Jiang, Yijun; Yu, Bing

    2013-12-01

    Microwave absorbing material plays a great role in electromagnetic pollution controlling, electromagnetic interference shielding and stealth technology, etc. The core-nanoshell composite materials doped with La were prepared by a solid-state reaction method, which is applied to the electromagnetic wave absorption. The core is magnetic fly-ash hollow cenosphere, and the shell is the nanosized ferrite doped with La. The thermal decomposition process of the sample was investigated by thermogravimetry and differential thermal analysis. The morphology and components of the composite materials were investigated by the X-ray diffraction analysis, the microstructure was observed by scanning electron microscope and transmission electron microscope. The results of vibrating sample magnetometer analysis indicated that the exchange-coupling interaction happens between ferrite of magnetic fly-ash hollow cenosphere and nanosized ferrite coating, which caused outstanding magnetic properties. The microwave absorbing property of the sample was measured by reflectivity far field radar cross section of radar microwave absorbing material with vector network analyzer. The results indicated that the exchange-coupling interaction enhanced magnetic loss of composite materials. Therefore, in the frequency of 5 GHz, the reflection coefficient can achieve -24 dB. It is better than single material and is consistent with requirements of the microwave absorbing material at the low-frequency absorption.

  11. Critical CRBR core pressure

    SciTech Connect

    Ju, F.D.

    1980-06-01

    The conditions are detailed under which gas pressure will cause or initiate failure in the structural containment of the fuel core. The Clinch River Breeder Reactor Plant is the prototype structure. Two general classes of problems have been studied, representing two entirely distinct configurations of containment failure. The first model determines the minimum pressure to lift a portion or the entire core from its containment. The second model estimates the critical pressure above which the fuel rods interior to the hexagonal fuel can warp, leading to blockage of the gas passages. Such blockage might cause further buildup of the gas pressure to a level causing the failure of the fuel rod containment in the hexagonal fuel container.

  12. Using core sets of the international classification of functioning, disability and health (ICF) to measure disability in vestibular disorders: study protocol.

    PubMed

    Grill, Eva; Furman, Joseph M; Alghwiri, Alia A; Müller, Martin; Whitney, Susan L

    2013-01-01

    Symptom frequency and severity in vestibular disorders often do not correlate well with patients' restrictions of activities of daily living and limitations of participation. Due to the lack of appropriate patient reported outcome measures (PRO), the extent of limitations and restrictions is mostly unknown. The International Classification of Functioning, Disability and Health (ICF) is a conceptual framework and classification to evaluate all aspects of health and disability. An ICF-based measure, the Vestibular and Participation Measure (VAP), was recently proposed. Also, an ICF Core Set for vertigo, dizziness and balance disorders was developed to describe what aspects of functioning should be measured. This study protocol describes the development and cross-cultural validation of a new measure, the VAP-extended (VAP-e), based on VAP and ICF Core Set on three continents. To determine objectivity and cross-cultural validity of the VAP and to find potentially redundant items, Rasch models will be used. The VAP-e will be created by modifying or adding items from the Activities and Participation and Environmental Factors component of the ICF Core Set. Reliability, objectivity and responsiveness of the VAP-e will be tested.

  13. Fabrication and spectroscopic studies of folic acid-conjugated Fe3O4@Au core-shell for targeted drug delivery application

    NASA Astrophysics Data System (ADS)

    Karamipour, Sh.; Sadjadi, M. S.; Farhadyar, N.

    2015-09-01

    Gold coated magnetite core shell is a kind of nanoparticle that include magnetic iron oxide core with a thin layer nanogold. Fe3O4-gold core-shell nanostructure can be used in biomedical applications such as magnetic bioseparation, bioimaging, targeting drug delivery and cancer treatment. In this study, the synthesis and characterization of gold coated magnetite nanoparticles were discussed. Magnetite nanoparticles with an average size of 6 nm in diameter were synthesized by the chemical co-precipitation method and gold-coated Fe3O4 core-shell nanostructures were produced with an average size of 11.5 nm in diameter by reduction of Au3+ with citrate ion in the presence of Fe3O4. Folate-conjugated gold coated magnetite nanoparticles were synthesized to targeting folate receptor that is overexpressed on the surface of cancerous cells. For this purpose, we used L-cysteine, as a bi-functional linker for attachment to gold surface and it was linked to the gold nanoparticles surface through its thiol group. Then, we conjugated amino-terminated nanoparticles to folic acid with an amide-linkage formation. These gold magnetic nanoparticles were characterized by various techniques such as X-ray powder diffraction (XRD) analysis, Fourier transform infrared spectrometer (FT-IR), UV-visible spectroscopy, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), dispersive analysis of X-ray (EDAX) and vibrating sample magnetometer (VSM) analysis. The magnetic and optical properties of Fe3O4 nanostructure were changed by gold coating and attachment of L-cysteine and folic acid to Fe3O4@Au nanoparticles.

  14. Purification, crystallization and preliminary X-ray diffraction study of human ribosomal protein L10 core domain

    SciTech Connect

    Nishimura, Mitsuhiro; Kaminishi, Tatsuya; Kawazoe, Masahito; Shirouzu, Mikako; Takemoto, Chie; Yokoyama, Shigeyuki; Tanaka, Akiko; Sugano, Sumio; Yoshida, Takuya; Ohkubo, Tadayasu; Kobayashi, Yuji

    2007-11-01

    A truncated variant of human ribosomal protien L10 was prepared and crystallized. Diffraction data were collected to 2.5 Å resolution. Eukaryotic ribosomal protein L10 is an essential component of the large ribosomal subunit, which organizes the architecture of the aminoacyl-tRNA binding site. The human L10 protein is also called the QM protein and consists of 214 amino-acid residues. For crystallization, the L10 core domain (L10CD, Phe34–Glu182) was recombinantly expressed in Escherichia coli and purified to homogeneity. A hexagonal crystal of L10CD was obtained by the sitting-drop vapour-diffusion method. The L10CD crystal diffracted to 2.5 Å resolution and belongs to space group P3{sub 1}21 or P3{sub 2}21.

  15. Fluid inclusions and preliminary studies of hydrothermal alteration in core hole PLTG-1, Platanares geothermal area, Honduras

    USGS Publications Warehouse

    Bargar, K.E.

    1991-01-01

    The Platanares geothermal area in western Honduras consists of more than 100 hot springs that issue from numerous hot-spring groups along the banks or within the streambed of the Quebrada de Agua Caliente (brook of hot water). Evaluation of this geothermal area included drilling a 650-m deep PLTG-1 drill hole which penetrated a surface mantling of stream terrace deposits, about 550 m of Tertiary andesitic lava flows, and Cretaceous to lower Tertiary sedimentary rocks in the lower 90 m of the drill core. Fractures and cavities in the drill core are partly to completely filled by hydrothermal minerals that include quartz, kaolinite, mixed-layer illite-smectite, barite, fluorite, chlorite, calcite, laumontite, biotite, hematite, marcasite, pyrite, arsenopyrite, stibnite, and sphalerite; the most common open-space fillings are calcite and quartz. Biotite from 138.9-m depth, dated at 37.41 Ma by replicate 40Ar/39 Ar analyses using a continuous laser system, is the earliest hydrothermal mineral deposited in the PLTG-1 drill core. This mid-Tertiary age indicates that at least some of the hydrothermal alteration encountered in the PLTG-1 drill core occured in the distant past and is unrelated to the present geothermal system. Furthermore, homogenization temperatures (Th) and melting-point temperatures (Tm) for fluid inclusions in two of the later-formed hydrothermal minerals, calcite and barite, suggest that the temperatures and concentration of dissolved solids of the fluids present at the time these fluid inclusions formed were very different from the present temperatures and fluid chemistry measured in the drill hole. Liquid-rich secondary fluid inclusions in barite and caicite from drill hole PLTG-1 have Th values that range from about 20??C less than the present measured temperature curve at 590.1-m depth to as much as 90??C higher than the temperature curve at 46.75-m depth. Many of the barite Th measurements (ranging between 114?? and 265??C) plot above the

  16. Drill core LB-08A, Bosumtwi impact structure, Ghana: Petrographic and shock metamorphic studies of material from the central uplift

    NASA Astrophysics Data System (ADS)

    Ferrière, Ludovic; Koeberl, Christian; Reimold, Wolf Uwe

    During a recent drilling project sponsored by the International Continental Scientific Drilling Progam (ICDP), two boreholes (LB-07A and LB-08A) were drilled into the crater fill of the Bosumtwi impact structure and the underlying basement, into the deep crater moat and the outer flank of the central uplift, respectively. The Bosumtwi impact structure in Ghana (West Africa), which is 10.5 km in diameter and 1.07 Myr old, is largely filled by Lake Bosumtwi. Here we present the lithostratigraphy of drill core LB-08A (recovered between 235.6 and 451.33 m depth below lake level) as well as the first mineralogical and petrographic observations of samples from this core. This drill core consists of approximately 25 m of polymict, clast-supported lithic breccia intercalated with suevite, which overlies fractured/brecciated metasediment that displays a large variation in lithology and grain size. The lithologies present in the central uplift are metasediments composed dominantly of fine-grained to gritty meta-graywacke, phyllite, and slate, as well as suevite and polymict lithic impact breccia. The suevites, principally present between 235.6 and 240.5 m and between 257.6 and 262.2 m, display a fine-grained fragmental matrix (about 39 to 45 vol%) and a variety of lithic and mineral clasts that include meta-graywacke, phyllite, slate, quartzite, carbon-rich organic shale, and calcite, as well as melt particles, fractured quartz, unshocked quartz, unshocked feldspar, quartz with planar deformation features (PDFs), diaplectic quartz glass, mica, epidote, sphene, and opaque minerals). The crater-fill suevite contains calcite clasts but no granite clasts, in contrast to suevite from outside the northern crater rim. The presence of melt particles in suevite samples from the uppermost 25 meters of the core and in suevite dikelets in the basement is an indicator of shock pressures exceeding 45 GPa. Quartz grains present in suevite and polymict lithic impact breccia abundantly

  17. Properties of a soft-core model of methanol: An integral equation theory and computer simulation study

    SciTech Connect

    Huš, Matej; Urbic, Tomaz; Munaò, Gianmarco

    2014-10-28

    Thermodynamic and structural properties of a coarse-grained model of methanol are examined by Monte Carlo simulations and reference interaction site model (RISM) integral equation theory. Methanol particles are described as dimers formed from an apolar Lennard-Jones sphere, mimicking the methyl group, and a sphere with a core-softened potential as the hydroxyl group. Different closure approximations of the RISM theory are compared and discussed. The liquid structure of methanol is investigated by calculating site-site radial distribution functions and static structure factors for a wide range of temperatures and densities. Results obtained show a good agreement between RISM and Monte Carlo simulations. The phase behavior of methanol is investigated by employing different thermodynamic routes for the calculation of the RISM free energy, drawing gas-liquid coexistence curves that match the simulation data. Preliminary indications for a putative second critical point between two different liquid phases of methanol are also discussed.

  18. Chandra Observation of RXJ1720.1+2638: Study of a Cluster Core Moving in its Own Environment

    NASA Astrophysics Data System (ADS)

    Mazzotta, P.; van Speybroeck, L.; David, L. P.; Forman, W. R.; Markevitch, M.; Vikhlinin, A.

    2000-12-01

    We have analyzed the Chandra observation of the distant (z=0.164) galaxy cluster RXJ1720.1+2638 in which we find a sharp edge and plateau in the X-ray surface brightness at about 250 h50-1 kpc and 130 h50-1 kpc from the X-ray peak respectively. These features are consistent with a density discontinuity and a density break, on angular scales <= 10''. The temperature profiles suggest that the edge and the break are the boundaries of a central, group-size (d≈ 380h50-1 kpc), dense, cold thermally isolated (T≈ 4 keV) gas cloud, embedded in a more diffuse hot (T≈ 10 keV) ambient intracluster. The density jump and the temperature change across the discontinuity are similar to the edge discovered by Chandra in A2142 and A3667, and suggest a subsonic motion of this central gas cloud with respect to the cluster itself. As for A2142 and A3667, the most natural explanation for this cluster is that we are observing a merger cluster. However the cluster appears to be relaxed just outside the two density features, thus we suggest that the merger is in the very last stage before the cluster become fully relaxed. We show that the gas inside the central cloud is not in hydrostatic equilibrium and, thus, the X-ray cluster mass determination on scales smaller than gas cloud size may be substantially influenced. The dimension of the moving cloud is comparable to the cluster core and to the Einstein ring. If, as we suspect, RXJ1720.1+2638 is not a ``special'' cluster and the core-size gas cloud motion phenomenon is present in many other clusters, then it may partially explain the discrepancy between X-ray and the strong lensing mass determination found in some systems. P.M. is supported by ESA fellowship.

  19. The core of tau-paired helical filaments studied by scanning transmission electron microscopy and limited proteolysis.

    PubMed

    von Bergen, Martin; Barghorn, Stefan; Müller, Shirley A; Pickhardt, Marcus; Biernat, Jacek; Mandelkow, Eva-Maria; Davies, Peter; Aebi, Ueli; Mandelkow, Eckhard

    2006-05-23

    In Alzheimer's disease and frontotemporal dementias the microtubule-associated protein tau forms intracellular paired helical filaments (PHFs). The filaments formed in vivo consist mainly of full-length molecules of the six different isoforms present in adult brain. The substructure of the PHF core is still elusive. Here we applied scanning transmission electron microscopy (STEM) and limited proteolysis to probe the mass distribution of PHFs and their surface exposure. Tau filaments assembled from the three repeat domain have a mass per length (MPL) of approximately 60 kDa/nm and filaments from full-length tau (htau40DeltaK280 mutant) have approximately 160 kDa/nm, compared with approximately 130 kDa/nm for PHFs from Alzheimer's brain. Polyanionic cofactors such as heparin accelerate assembly but are not incorporated into PHFs. Limited proteolysis combined with N-terminal sequencing and mass spectrometry of fragments reveals a protease-sensitive N-terminal half and semiresistant PHF core starting in the first repeat and reaching to the C-terminus of tau. Continued proteolysis leads to a fragment starting at the end of the first repeat and ending in the fourth repeat. PHFs from tau isoforms with four repeats revealed an additional cleavage site within the middle of the second repeat. Probing the PHFs with antibodies detecting epitopes either over longer stretches in the C-terminal half of tau or in the fourth repeat revealed that they grow in a polar manner. These data describe the physical parameters of the PHFs and enabled us to build a model of the molecular arrangement within the filamentous structures.

  20. On sulfur core level binding energies in thiol self-assembly and alternative adsorption sites: An experimental and theoretical study

    SciTech Connect

    Jia, Juanjuan; Kara, Abdelkader E-mail: vladimir.esaulov@u-psud.fr; Pasquali, Luca; Bendounan, Azzedine; Sirotti, Fausto; Esaulov, Vladimir A. E-mail: vladimir.esaulov@u-psud.fr

    2015-09-14

    Characteristic core level binding energies (CLBEs) are regularly used to infer the modes of molecular adsorption: orientation, organization, and dissociation processes. Here, we focus on a largely debated situation regarding CLBEs in the case of chalcogen atom bearing molecules. For a thiol, this concerns the case when the CLBE of a thiolate sulfur at an adsorption site can be interpreted alternatively as due to atomic adsorption of a S atom, resulting from dissociation. Results of an investigation of the characteristics of thiol self-assembled monolayers (SAMs) obtained by vacuum evaporative adsorption are presented along with core level binding energy calculations. Thiol ended SAMs of 1,4-benzenedimethanethiol (BDMT) obtained by evaporation on Au display an unconventional CLBE structure at about 161.25 eV, which is close to a known CLBE of a S atom on Au. Adsorption and CLBE calculations for sulfur atoms and BDMT molecules are reported and allow delineating trends as a function of chemisorption on hollow, bridge, and atop sites and including the presence of adatoms. These calculations suggest that the 161.25 eV peak is due to an alternative adsorption site, which could be associated to an atop configuration. Therefore, this may be an alternative interpretation, different from the one involving the adsorption of atomic sulfur resulting from the dissociation process of the S–C bond. Calculated differences in S(2p) CLBEs for free BDMT molecules, SH group sulfur on top of the SAM, and disulfide are also reported to clarify possible errors in assignments.

  1. Bent core liquid crystal elastomers

    SciTech Connect

    Verduzco, R.; DiMasi, E.; Luchette, P.; Ho Hong, S.; Harden, J.; Palffy-Muhoray, P.; Kilbey II, S.M.; Sprunt, S.; Gleeson, G.T. Jakli, A.

    2010-07-28

    Liquid crystal (LC) elastomers with bent-core side-groups incorporate the properties of bent-core liquid crystals in a flexible and self-supporting polymer network. Bent-core liquid crystal elastomers (BCEs) with uniform alignment were prepared by attaching a reactive bent-core LC to poly(hydrogenmethylsiloxane) and crosslinking with a divinyl crosslinker. Phase behavior studies indicate a nematic phase over a wide temperature range that approaches room temperature, and thermoelastic measurements show that these BCEs can reversibly change their length by more than a factor of two upon heating and cooling. Small-angle X-ray scattering studies reveal multiple, broad low-angle peaks consistent with short-range smectic C order of the bent-core side groups. A comparison of these patterns with predictions of a Landau model for short-range smectic C order shows that the length scale for smectic ordering in BCEs is similar to that seen in pure bent-core LCs. The combination of rubber elasticity and smectic ordering of the bent-core side groups suggests that BCEs may be promising materials for sensing, actuating, and other advanced applications.

  2. Neutronics and Thermal Hydraulics Study for Using a Low-Enriched Uranium Core in the Advanced Test Reactor -- 2008 Final Report

    SciTech Connect

    G. S. Chang; M. A. Lillo; R. G. Ambrosek

    2008-06-01

    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 fuel cycle burnup comparison analysis. Using the current HEU U 235 enrichment of 93.0 % as a baseline, an analysis was performed to determine the low-enriched uranium (LEU) density and U-235 enrichment required in the fuel meat to yield an equivalent K-eff versus effective full power days (EFPDs) between the HEU and the LEU cores. The MCNP ATR 1/8th core model was used to optimize the U 235 loading in the LEU core, such that the differences in K-eff and heat flux profiles between the HEU and LEU cores were minimized. The depletion methodology MCWO was used to calculate K-eff versus EFPDs in this paper. The MCWO-calculated results for the LEU demonstrated adequate excess reactivity such that the K-eff versus EFPDs plot is similar to the ATR reference HEU case study. Each HEU fuel element contains 19 fuel plates with a fuel meat thickness of 0.508 mm (20 mil). In this work, the proposed LEU (U-10Mo) core conversion case with nominal fuel meat thickness of 0.330 mm (13 mil) and U-235 enrichment of 19.7 wt% is used to optimize the radial heat flux profile by varying the fuel meat thickness from 0.191 mm (7.0 mil) to 0.330 mm (13.0 mil) at the inner 4 fuel plates (1-4) and outer 4 fuel plates (16-19). A 0.8g of Boron-10, a burnable absorber, was added in the inner and outer plates to reduce the initial excess reactivity, and the peak to average ratio of the

  3. Asenapine as adjunctive treatment for acute mania associated with bipolar disorder: results of a 12-week core study and 40-week extension.

    PubMed

    Szegedi, Armin; Calabrese, Joseph R; Stet, Let; Mackle, Mary; Zhao, Jun; Panagides, John

    2012-02-01

    In a 12-week randomized, placebo-controlled study evaluating the efficacy and safety of adjunctive asenapine, bipolar I disorder patients experiencing manic or mixed episodes despite pretreatment with lithium or valproate monotherapy were treated with flexible-dose, twice-daily asenapine 5 or 10 mg (n = 158) or placebo (n = 166). The primary efficacy end point was change from baseline Young Mania Rating Scale (YMRS) total score at week 3. Secondary outcomes included YMRS response and remission and Clinical Global Impression for Bipolar Disorder and Montgomery-Asberg Depression Rating Scale score changes. Patients completing the core study were eligible for a 40-week double-blind extension assessing safety and tolerability. Adjunctive asenapine significantly improved mania versus placebo at week 3 (primary end point) and weeks 2 to 12. The YMRS response rates were similar at week 3 but significantly better with asenapine at week 12. The YMRS remission rates and changes from baseline on Clinical Global Impression for Bipolar Disorder for mania and overall illness were significantly better with asenapine at weeks 3 and 12. No other statistically significant differences on secondary outcomes were observed. Only a small number of patients entered the extension, making firm statistical conclusions on efficacy difficult. Treatment-emergent adverse events reported by 5% or more of asenapine patients and at twice the incidence of placebo were sedation, somnolence, depression/depressive symptoms, oral hypoesthesia, and increased weight in the 12-week core study. Adjunctive asenapine to lithium or valproate was more effective than mood stabilizer monotherapy in the core study and was well tolerated for up to 52 weeks.

  4. Magnetic field directed assembly of superstructures of ferrite-ferroelectric core-shell nanoparticles and studies on magneto-electric interactions

    SciTech Connect

    Srinivasan, G. Sreenivasulu, G.; Benoit, Crystal; Petrov, V. M.; Chavez, F.

    2015-05-07

    Composites of ferromagnetic and ferroelectric are of interest for studies on mechanical strain mediated magneto-electric (ME) interactions and for useful technologies. Here, we report on magnetic-field-assisted-assembly of barium titanate (BTO)-nickel ferrite (NFO) core-shell particles into linear chains and 2D/3D arrays and measurements of ME effects in such assemblies. First, we synthesized the core-shell nano-particles with 50–600 nm BTO and 10–200 nm NFO by chemical self-assembly by coating the ferroic particles with complementary coupling groups and allowing them to self-assemble in the presence of a catalyst via the “click” reaction. The core-shell structure was confirmed with electron microscopy and scanning probe microscopy. We obtained superstructure of the core-shell particles by subjecting them to a magnetic field gradient that exerts an attractive force on the particles and align them toward the regions of high field strengths. At low particle concentration, linear chains were formed and they evolved into 2D and 3D arrays at high particle concentrations. Magnetoelectric characterization on unassembled films and assembled arrays has been performed through measurements of low-frequency ME voltage coefficient (MEVC) by subjecting the sample to a bias magnetic field and an ac magnetic field. The MEVC is higher for field-assembled samples than for unassembled films and is found to be sensitive to field orientation with a higher MEVC for magnetic fields parallel to the array direction than for magnetic fields perpendicular to the array. A maximum MEVC of 20 mV/cm Oe, one of the highest reported for any bulk nanocomposite, is measured across the array thickness. A model is provided for ME coupling in the superstructures of BTO-NFO particulate composites. First, we estimated the MEVC for a free-standing BTO-NFO core-shell particle and then extended the model to include an array of linear chains of the particles. The theoretical estimates are in

  5. Probing the core-mantle boundary beneath Europe and Western Eurasia: A detailed study using PcP

    NASA Astrophysics Data System (ADS)

    Gassner, Alexandra; Thomas, Christine; Krüger, Frank; Weber, Michael

    2015-09-01

    We use PcP (the core reflected P phase) recordings of deep earthquakes and nuclear explosions from the Gräfenberg (Germany) and NORSAR (Norway) arrays to investigate the core-mantle boundary region beneath Europe and western Eurasia. We find evidence for a previously unknown ultra-low velocity zone 600 km south-east of Moscow, located at the edge of a middle-size low shear- velocity region imaged in seismic tomography that is located beneath the Volga river region. The observed amplitude variations of PcP can be modelled by velocity reductions of P and S-waves of -5% and -15%, respectively, with a density increase of +15%. Travel time delays of pre-and postcursors are indicating a thickness of about 13 km for this ultra-low velocity region (ULVZ). However, our modelling also reveals highly ambiguous amplitude variations of PcP and a reflection off the top of the anomaly for various ULVZs and topography models. Accordingly, large velocity contrasts of up to -10% in VP and -20% in VS cannot be excluded. In general, the whole Volga river region shows a complex pattern of PcP amplitudes caused most likely by CMB undulations. Further PcP probes beneath Paris, Kiev and northern Italy indicate likely normal CMB conditions, whereas the samples below Finland and the Hungary-Slovakia border yield strongly amplified PcP signals suggesting strong CMB topography effects. We evaluate the amplitude behaviour of PcP as a function of distance and several ULVZ models using the 1D reflectivity and the 2D Gauss beam method. The influence of the velocity and density perturbations is analysed as well as the anomaly thickness, the dominant period of the source wavelet and interface topographies. Strong variation of the PcP amplitude are obtained as a function of distance and of the impedance contrast. We also consider two types of topographies: undulations atop the CMB in the presence of flat ULVZs and vice versa. Where a broad range of CMB topography dimensions lead to large Pc

  6. Academic Rigor: The Core of the Core

    ERIC Educational Resources Information Center

    Brunner, Judy

    2013-01-01

    Some educators see the Common Core State Standards as reason for stress, most recognize the positive possibilities associated with them and are willing to make the professional commitment to implementing them so that academic rigor for all students will increase. But business leaders, parents, and the authors of the Common Core are not the only…

  7. Core Stability Training for Injury Prevention

    PubMed Central

    Huxel Bliven, Kellie C.; Anderson, Barton E.

    2013-01-01

    Context: Enhancing core stability through exercise is common to musculoskeletal injury prevention programs. Definitive evidence demonstrating an association between core instability and injury is lacking; however, multifaceted prevention programs including core stabilization exercises appear to be effective at reducing lower extremity injury rates. Evidence Acquisition: PubMed was searched for epidemiologic, biomechanic, and clinical studies of core stability for injury prevention (keywords: “core OR trunk” AND “training OR prevention OR exercise OR rehabilitation” AND “risk OR prevalence”) published between January 1980 and October 2012. Articles with relevance to core stability risk factors, assessment, and training were reviewed. Relevant sources from articles were also retrieved and reviewed. Results: Stabilizer, mobilizer, and load transfer core muscles assist in understanding injury risk, assessing core muscle function, and developing injury prevention programs. Moderate evidence of alterations in core muscle recruitment and injury risk exists. Assessment tools to identify deficits in volitional muscle contraction, isometric muscle endurance, stabilization, and movement patterns are available. Exercise programs to improve core stability should focus on muscle activation, neuromuscular control, static stabilization, and dynamic stability. Conclusion: Core stabilization relies on instantaneous integration among passive, active, and neural control subsystems. Core muscles are often categorized functionally on the basis of stabilizing or mobilizing roles. Neuromuscular control is critical in coordinating this complex system for dynamic stabilization. Comprehensive assessment and training require a multifaceted approach to address core muscle strength, endurance, and recruitment requirements for functional demands associated with daily activities, exercise, and sport. PMID:24427426

  8. Inner Core Structure Behind the PKP Core Phase Triplication

    NASA Astrophysics Data System (ADS)

    Blom, N.; Paulssen, H.; Deuss, A. F.; Waszek, L.

    2015-12-01

    Despite its small size, the Earth's inner core plays an important role in the Earth's dynamics. Because it is slowly growing, its structure - and the variation thereof with depth - may reveal important clues about the history of the core, its convection and the resulting geodynamo. Learning more about this structure has been a prime effort in the past decades, leading to discoveries about anisotropy, hemispheres and heterogeneity in the inner core in general. In terms of detailed structure, mainly seismic body waves have contributed to these advances. However, at depths between ~100-200 km, the seismic structure is relatively poorly known. This is a result of the PKP core phase triplication and the existence of strong precursors to PKP phases, whose simultaneous arrival hinders the measurement of inner core waves PKIKP at epicentral distances between roughly 143-148°. As a consequence, the interpretation of deeper structure also remains difficult. To overcome these issues, we stack seismograms in slowness and time, separating PKP and PKIKP phases which arrive simultaneously, but with different slowness. We apply this method to study the inner core's Western hemisphere between South and Central America using paths travelling in the quasi-polar direction between epicentral distances of 140-150°. This enables us to measure PKiKP-PKIKP differential travel times up to greater epicentral distance than has previously been done. The resulting differential travel time residuals increase with epicentral distance, indicating a marked increase in seismic velocity with depth compared to reference model AK135 for the studied polar paths. Assuming a homogeneous outer core, these findings can be explained by either (i) inner core heterogeneity due to an increase in isotropic velocity, or (ii) increase in anisotropy over the studied depth range. Our current data set cannot distinguish between the two hypotheses, but in light of previous work we prefer the latter interpretation.

  9. Ice-cored moraine degradation mapped and quantified using an unmanned aerial vehicle: A case study from a polythermal glacier in Svalbard

    NASA Astrophysics Data System (ADS)

    Tonkin, T. N.; Midgley, N. G.; Cook, S. J.; Graham, D. J.

    2016-04-01

    Ice-cored lateral-frontal moraines are common at the margins of receding high-Arctic valley glaciers, but the preservation potential of these features within the landform record is unclear. Recent climatic amelioration provides an opportunity to study the morphological evolution of these landforms as they de-ice. This is important because high-Arctic glacial landsystems have been used as analogues for formerly glaciated areas in the mid-latitudes. This study uses SfM (Structure-from-Motion) photogrammetry and a combination of archive aerial and UAV (unmanned aerial vehicle) derived imagery to investigate the degradation of an ice-cored lateral-frontal moraine at Austre Lovénbreen, Svalbard. Across the study area as a whole, over an 11-year period, the average depth of surface lowering was - 1.75 ± 0.89 m. The frontal sections of the moraine showed low or undetectable rates of change. Spatially variable rates of surface lowering are associated with differences in the quantity of buried ice within the structure of the moraine. Morphological change was dominated by surface lowering, with limited field evidence of degradation via back-wastage. This permits the moraine a greater degree of stability than previously observed at other sites in Svalbard. It is unclear whether the end point will be a fully stabilised ice-cored moraine, in equilibrium with its environment, or an ice-free lateral-frontal moraine complex. Controls on geomorphological change (e.g. topography and climate) and the preservation potential of the lateral-frontal moraine are discussed. The methods used by this research also demonstrate the potential value of SfM photogrammetry and unmanned aerial vehicles for monitoring environmental change and are likely to have wider applications in other geoscientific sub-disciplines.

  10. Environmental Magnetic Study of Core MD01-2414 from Central of Okhotsk Sea: Significance of Environmental Changes since 1.8 Ma

    NASA Astrophysics Data System (ADS)

    LEE, Teh-Quei; CHOU, Yu-Min; WANG, Liang-Chi; LO, Li

    2015-04-01

    The Okhotsk Sea is an important marginal sea at northeast Asia due to that it represents the lowest latitude and the largest region with seasonal sea-ice cover, which play a very significant role in the climatic and environmental changes. This study used environmental magnetic analyses to study the marine sediment core, MD01-2414, taken from the central of Okhotsk Sea. The age model was set up mainly by the paleomagnetic records in addition to the correlation of magnetic susceptibility with the other cores, which implied an age interval since 1.8 Ma. The variations of magnetic susceptibility and ARM/c of this core show that high abundant but relative coarse grain of magnetic minerals appeared in the glacial periods, while low abundance with finer grain appeared in the interglacial periods. This suggests that the different sources and transportation pathways of sediments could be influenced by sea-ice cover condition in the area of studied. In addition, high ARM/SIRM indicated that very fine grain magnetic minerals was found in some interglacial periods, FORC diagram results of those samples show obviously biogenic magnetite dominates the magnetic mineral assemblages. This suggests ARM/SIRM ratio could be a suitable index of biogenic productivity of magnetic bacteria in the sea floor sediment. To compare the ARM/SIRM ratio with primary productivity index of diatom abundance, total biogenic productivity index of opal, Mg/Al, and Ca/Al, the results show sea-ice condition could influence the ocean productivity of surface water even bottom water.

  11. Constraints on formation processes of two coarse-grained calcium- aluminum-rich inclusions: a study of mantles, islands and cores

    USGS Publications Warehouse

    Meeker, G.P.

    1995-01-01

    Many coarse-grained calcium- aluminum-rich inclusions (CAIs) contain features that are inconsistent with equilibrium liquid crystallization models of origin. Spinel-free islands (SFIs) in spinel-rich cores of Type B CAIs are examples of such features. One model previously proposed for the origin of Allende 5241, a Type B1 CAI containing SFIs, involves the capture and assimilation of xenoliths by a liquid droplet in the solar nebula (El Goresy et al, 1985; MacPherson et al 1989). This study reports new textural and chemical zoning data from 5241 and identifies previously unrecognized chemical zoning patterns in the melilite mantle and in a SFI. -from Author

  12. Space Station Furnace Facility Core. Requirements definition and conceptual design study. Volume 2: Technical report. Appendix 6: Technical summary reports

    NASA Astrophysics Data System (ADS)

    1992-05-01

    The Space Station Furnace Facility (SSFF) is a modular facility for materials research in the microgravity environment of the Space Station Freedom (SSF). The SSFF is designed for crystal growth and solidification research in the fields of electronic and photonic materials, metals and alloys, and glasses and ceramics and will allow for experimental determination of the role of gravitational forces in the solidification process. The facility will provide a capability for basic scientific research and will evaluate the commercial viability of low-gravity processing of selected technologically important materials. The facility is designed to support a complement of furnace modules as outlined in the Science Capabilities Requirements Document (SCRD). The SSFF is a three rack facility that provides the functions, interfaces, and equipment necessary for the processing of the furnaces and consists of two main parts: the SSFF Core Rack and the two Experiment Racks. The facility is designed to accommodate two experimenter-provided furnace modules housed within the two experiment racks, and is designed to operate these two furnace modules simultaneously. The SCRD specifies a wide range of furnace requirements and serves as the basis for the SSFF conceptual design. SSFF will support automated processing during the man-tended operations and is also designed for crew interface during the permanently manned configuration. The facility is modular in design and facilitates changes as required, so the SSFF is adept to modifications, maintenance, reconfiguration, and technology evolution.

  13. The Core Pattern Analysis on Chinese Herbal Medicine for Sjögren's syndrome: A Nationwide Population-Based Study.

    PubMed

    Chang, Ching-Mao; Chu, Hsueh-Ting; Wei, Yau-Huei; Chen, Fang-Pey; Wang, Shengwen; Wu, Po-Chang; Yen, Hung-Rong; Chen, Tzeng-Ji; Chang, Hen-Hong

    2015-01-01

    This large-scale survey aimed to evaluate frequencies and patterns of Chinese herbal medicine (CHM) used for Sjögren's syndrome (SS) in Taiwan by analyzing the National Health Insurance Research Database (NHIRD) for cases in which CHM was used as an alternative therapy to Western medicine for improving patients' discomforts. We analyzed cases of SS principal diagnosis (ICD-9:710.2) with a catastrophic illness certificate (CIC) in traditional Chinese medicine (TCM) outpatient clinics from three cohorts of the Longitudinal Health Insurance Database (LHID) in the NHIRD between 2002 and 2011. CHM prescription patterns for SS were evaluated from claimed visitation files and corresponding prescription files. There were 15,914 SS patients with CIC (SS/CIC), and we found only 130 SS/CIC cases visiting TCM clinics in LHID2000, 133 in LHID2005, and 126 in LHID2010. After removing duplicate data, 366 SS/CIC and 4,867 visits were analyzed. The 50-59 year age group showed the highest ratio (29.51%) in both women and men. "Qi-Ju-Di-Huang-Wan" and "Xuan-Shen" (Scrophularia ningpoensis Hemsl.) was the most commonly used formula and single herb, respectively. "Qi-Ju-Di-Huang-Wan, Gan-Lu-Yin, Xuan-Shen, Mai-Men-Dong (Ophiopogon japonicus (L. f.) Ker-Gawl.), and Sheng-Di-Huang (raw Rehmannia glutinosa Libosch)" were the core pattern prescriptions in treating SS/CIC. PMID:25923413

  14. A numerical modeling study of the East Australian Current encircling and overwashing a warm-core eddy

    NASA Astrophysics Data System (ADS)

    MacDonald, H. S.; Roughan, M.; Baird, M. E.; Wilkin, J.

    2013-01-01

    AbstractWarm-<span class="hlt">core</span> eddies (WCEs) often form in the meanders of Western Boundary Currents (WBCs). WCEs are frequently overwashed with less dense waters sourced from the WBC. We use the Regional Ocean Modelling System to investigate the ocean state during the overwashing of one such WCE in October 2008 in the East Australian Current (EAC). Comparisons of model outputs with satellite sea surface temperature and vertical profiles show that the model provides a realistic simulation of the eddy during the period when the EAC encircled and then overwashed the eddy. During the encircling stage, an eddy with closed circulation persisted at depth. In the surface EAC water entered from the north, encircled the eddy and exited to the east. The overwashing stage was initiated by the expulsion of cyclonic vorticity. For the following 8 days after the expulsion, waters from the EAC washed over the top of the eddy, transferring heat and anticyclonic vorticity radially-inward. After approximately one rotation period of overwashing, the eddy separated. The overwashing creates a two-layer system that forms a subsurface maximum velocity at the interface of the two layers. Analysis of water mass properties, Eulerian tracer dynamics, and Lagrangian particle tracks show that the original eddy sinks 10-50 m during the overwashing period. Overwashing has been observed in many WBCs and occurs in most WCEs in the western Tasman Sea.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17698426','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17698426"><span id="translatedtitle">Lactoperoxidase folding and catalysis relies on the stabilization of the alpha-helix rich <span class="hlt">core</span> domain: a thermal unfolding <span class="hlt">study</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boscolo, Barbara; Leal, Sónia S; Ghibaudi, Elena M; Gomes, Cláudio M</p> <p>2007-09-01</p> <p>Lactoperoxidase (LPO) belongs to the mammalian peroxidase family and catalyzes the oxidation of halides, pseudo-halides and a number of aromatic substrates at the expense of hydrogen peroxide. Despite the complex physiological role of LPO and its potential involvement in carcinogenic mechanisms, cystic fibrosis and inflammatory processes, little is known on the folding and structural stability of this protein. We have undertaken an investigation of the conformational dynamics and catalytic properties of LPO during thermal unfolding, using complementary biophysical techniques (differential scanning calorimetry, electron spin resonance, optical absorption, fluorescence and circular dichroism spectroscopies) together with biological activity assays. LPO is a particularly stable protein, capable of maintaining catalysis and structural integrity up to a high temperature, undergoing irreversible unfolding at 70 degrees C. We have observed that the first stages of the thermal denaturation involve a minor conformational change occurring at 40 degrees C, possibly at the level of the protein beta-sheets, which nevertheless does not result in an unfolding transition. Only at higher temperature, the protein hydrophobic <span class="hlt">core</span>, which is rich in alpha-helices, unfolds with concomitant disruption of the catalytic heme pocket and activity loss. Evidences concerning the stabilizing role of the disulfide bridges and the covalently bound heme cofactor are shown and discussed in the context of understanding the structural stability determinants in a relatively large protein.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25923413','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25923413"><span id="translatedtitle">The <span class="hlt">Core</span> Pattern Analysis on Chinese Herbal Medicine for Sjögren's syndrome: A Nationwide Population-Based <span class="hlt">Study</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chang, Ching-Mao; Chu, Hsueh-Ting; Wei, Yau-Huei; Chen, Fang-Pey; Wang, Shengwen; Wu, Po-Chang; Yen, Hung-Rong; Chen, Tzeng-Ji; Chang, Hen-Hong</p> <p>2015-01-01</p> <p>This large-scale survey aimed to evaluate frequencies and patterns of Chinese herbal medicine (CHM) used for Sjögren's syndrome (SS) in Taiwan by analyzing the National Health Insurance Research Database (NHIRD) for cases in which CHM was used as an alternative therapy to Western medicine for improving patients' discomforts. We analyzed cases of SS principal diagnosis (ICD-9:710.2) with a catastrophic illness certificate (CIC) in traditional Chinese medicine (TCM) outpatient clinics from three cohorts of the Longitudinal Health Insurance Database (LHID) in the NHIRD between 2002 and 2011. CHM prescription patterns for SS were evaluated from claimed visitation files and corresponding prescription files. There were 15,914 SS patients with CIC (SS/CIC), and we found only 130 SS/CIC cases visiting TCM clinics in LHID2000, 133 in LHID2005, and 126 in LHID2010. After removing duplicate data, 366 SS/CIC and 4,867 visits were analyzed. The 50-59 year age group showed the highest ratio (29.51%) in both women and men. "Qi-Ju-Di-Huang-Wan" and "Xuan-Shen" (Scrophularia ningpoensis Hemsl.) was the most commonly used formula and single herb, respectively. "Qi-Ju-Di-Huang-Wan, Gan-Lu-Yin, Xuan-Shen, Mai-Men-Dong (Ophiopogon japonicus (L. f.) Ker-Gawl.), and Sheng-Di-Huang (raw Rehmannia glutinosa Libosch)" were the <span class="hlt">core</span> pattern prescriptions in treating SS/CIC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930013160','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930013160"><span id="translatedtitle">Space Station Furnace Facility <span class="hlt">Core</span>. Requirements definition and conceptual design <span class="hlt">study</span>. Volume 2: Technical report. Appendix 6: Technical summary reports</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1992-01-01</p> <p>The Space Station Furnace Facility (SSFF) is a modular facility for materials research in the microgravity environment of the Space Station Freedom (SSF). The SSFF is designed for crystal growth and solidification research in the fields of electronic and photonic materials, metals and alloys, and glasses and ceramics and will allow for experimental determination of the role of gravitational forces in the solidification process. The facility will provide a capability for basic scientific research and will evaluate the commercial viability of low-gravity processing of selected technologically important materials. The facility is designed to support a complement of furnace modules as outlined in the Science Capabilities Requirements Document (SCRD). The SSFF is a three rack facility that provides the functions, interfaces, and equipment necessary for the processing of the furnaces and consists of two main parts: the SSFF <span class="hlt">Core</span> Rack and the two Experiment Racks. The facility is designed to accommodate two experimenter-provided furnace modules housed within the two experiment racks, and is designed to operate these two furnace modules simultaneously. The SCRD specifies a wide range of furnace requirements and serves as the basis for the SSFF conceptual design. SSFF will support automated processing during the man-tended operations and is also designed for crew interface during the permanently manned configuration. The facility is modular in design and facilitates changes as required, so the SSFF is adept to modifications, maintenance, reconfiguration, and technology evolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4165098','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4165098"><span id="translatedtitle">A <span class="hlt">study</span> on literature obsolescence and <span class="hlt">core</span> journals’ cost-benefit in citations of the ‘Scientific Medical Journal of Ahwaz’</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zare-Farashbandi, Firoozeh; Mohammadi, Parastoo Parsaei</p> <p>2014-01-01</p> <p>Introduction: One of the methods of identifying <span class="hlt">core</span> and popular resources is by citation evaluation. Using citation evaluation, the librarians of the Acquisition Department can use quantitative methods to indentify <span class="hlt">core</span> and popular resources among numerous information resources and make serious savings in the library's budget, by acquiring these <span class="hlt">core</span> resources and eliminating useless ones. The aim of this <span class="hlt">study</span> is assessing literature obsolescence and <span class="hlt">core</span> journals’ cost-benefit in citations of the ‘Scientific Medical Journal of Ahwaz’. Materials and Methods: This <span class="hlt">study</span> is a descriptive and cross-sectional survey that uses citation analysis. Sampling is objective sampling from all documents from years 1364 (1985) to 1385 (2006), and the population comprises of 6342 citations of the articles published in ‘Scientific Medical Journal of Ahwaz’. Data collection is done through referring to the original documents and the data is analyzed using the Excel software, and for descriptive and analytical statistics the cost-benefit formula and Bradford law formula are used. Results: Findings showed that the average citation for each document in the ‘Scientific Medical Journal of Ahwaz’ was 15.81. The average citation to international sources was 14.37, and the average citation to national sources was 1.44. The literature obsolescence of Farsi documents in this <span class="hlt">study</span> was 15 years, while it was equal to 20 years for English documents. The highly cited Farsi journals were (sorted based on citation in descending order): ‘Scientific Medical Journal of Ahwaz’, ‘Daroudarman’, ‘Nabz,’ and ‘Journal of Medical School, Shahid Beheshti University of Medical Sciences’. The highly cited English journals were (sorted based on citation in descending order): ‘Pediatrics’, ‘The New England Journal of Medicine’, ‘Gastroenterology’ and ‘Medicine’. All of these four journals are part of the ISI database and have good impact factors in the Journal</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3966415','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3966415"><span id="translatedtitle">Hedyotis diffusa Combined with Scutellaria barbata Are the <span class="hlt">Core</span> Treatment of Chinese Herbal Medicine Used for Breast Cancer Patients: A Population-Based <span class="hlt">Study</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yeh, Yuan-Chieh; Chen, Hsing-Yu; Yang, Sien-Hung; Lin, Yi-Hsien; Chiu, Jen-Hwey; Lin, Yi-Hsuan; Chen, Jiun-Liang</p> <p>2014-01-01</p> <p>Traditional Chinese medicine (TCM), which is the most common type of complementary and alternative medicine (CAM) used in Taiwan, is increasingly used to treat patients with breast cancer. However, large-scale <span class="hlt">studies</span> on the patterns of TCM prescriptions for breast cancer are still lacking. The aim of this <span class="hlt">study</span> was to determine the <span class="hlt">core</span> treatment of TCM prescriptions used for breast cancer recorded in the Taiwan National Health Insurance Research Database. TCM visits made for breast cancer in 2008 were identified using ICD-9 codes. The prescriptions obtained at these TCM visits were evaluated using association rule mining to evaluate the combinations of Chinese herbal medicine (CHM) used to treat breast cancer patients. A total of 37,176 prescriptions were made for 4,436 outpatients with breast cancer. Association rule mining and network analysis identified Hedyotis diffusa plus Scutellaria barbata as the most common duplex medicinal (10.9%) used for the <span class="hlt">core</span> treatment of breast cancer. Jia-Wei-Xiao-Yao-San (19.6%) and Hedyotis diffusa (41.9%) were the most commonly prescribed herbal formula (HF) and single herb (SH), respectively. Only 35% of the commonly used CHM had been <span class="hlt">studied</span> for efficacy. More clinical trials are needed to evaluate the efficacy and safety of these CHM used to treat breast cancer. PMID:24734104</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20995580','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20995580"><span id="translatedtitle">Reactor Controllability of 3-Region-<span class="hlt">Core</span> Molten Salt Reactor System - A <span class="hlt">Study</span> on Load Following Capability</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Takahisa Yamamoto; Koshi Mitachi; Masatoshi Nishio</p> <p>2006-07-01</p> <p>The Molten Salt Reactor (MSR) systems are liquid-fueled reactors that can be used for actinide burning, production of electricity, production of hydrogen, and production of fissile fuels (breeding). Thorium (Th) and uranium-233 ({sup 233}U) are fertile and fissile of the MSR systems, and dissolved in a high-temperature molten fluoride salt (fuel salt) with a very high boiling temperature (up to 1650 K), that is both the reactor nuclear fuel and the coolant. The MSR system is one of the six advanced reactor concepts identified by the Generation IV International Forum (GIF) as a candidate for cooperative development. In the MSR system, fuel salt flows through a fuel duct constructed around a reactor <span class="hlt">core</span> and fuel channel of a graphite moderator accompanied by fission reaction and heat generation, and flows out to an external-loop system consisted of a heat exchanger and a circulation pump. Due to the motion of fuel salt, delayed neutron precursors that are one of the source of neutron production make to change their position between the fission reaction and neutron emission events and decay even occur in the external loop system. Hence the reactivity and effective delayed neutron precursor fraction of the MSR system are lower than those of solid fuel reactor systems such as Boiling Water Reactors (BWRs) and Pressurised Water Reactor (PWRs). Since all of the presently operating nuclear power reactors utilize solid fuel, little attention had been paid to the MSR analysis of the reactivity loss and reactor characteristics change caused by the fuel salt circulation. Sides et al. and Shimazu et al. developed MSR analytical models based on the point reactor kinetics model to consider the effect of fuel salt flow. Their models represented a reactor as having six zones for fuel salt and three zones for the graphite moderator. Since their models employed the point reactor kinetics model and the rough temperature approximation, their results were not sufficiently accurate to</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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