Moessbauer study in thin films of FeSi2 and FeSe systems

NASA Technical Reports Server (NTRS)

Escue, W. J.; Aggarwal, K.; Mendiratta, R. G.

1978-01-01

Thin films of FeSi2 and FeSe were studied using Moessbauer spectroscopy information regarding dangling bond configuration and nature of crystal structure in thin films was derived. A significant influence of crystalline aluminum substrate on film structure was observed.

Hematite at Meridiani Planum and Gusev Crater as identified by the Moessbauer Spectrometer MIMOS II

NASA Astrophysics Data System (ADS)

Klingelhoefer, G.; Morris, R. V.; Rodionov, D.; Schroeder, C.; de Souza, P. A.; Yen, A.; Renz, F.; Wdowiak, T.

2004-12-01

The Moessbauer (MB) spectrometers on the MER rovers Opportunity and Spirit, which landed on Mars in January 2004, have identified the iron-containing mineral hematite (a-Fe2O3) at both landing sites. On Earth, hematite can occur either by itself or with other iron oxides as massive deposits, in veins , and as particles dispersed through a silicate or other matrix material. Hematite particle size can range from nanophase (superparamagnetic) to multidomain and particle shape ranges from equant to acicular to platy. Fine-grained hematite is red in color and is a pigmenting agent. Coarse-grained hematite can be spectrally neutral (gray) at visible wavelengths. Substitutional impurities, particularly Al, are common in hematite. Chemically pure, coarse-grained, and well-crystalline hematite has a magnetic transition (the Morin transition) at ~260 K. Moessbauer spectra, recorded as a function of temperature, provide a way to characterize Martian hematite with respect to some of the physical and chemical characteristics. At Meridiani Planum besides the iron-sulfate mineral jarosite also the Fe-oxide hematite has been identified by the Moessbauer spectrometer, mainly in three distinct types of reservoir: - outcrop matrix material dominated by the mineral jarosite in the MB spectrum, certain basaltic soils, and mm-sized spherules dubbed blueberries. Moessbauer spectra of each reservoir yield a distinct set of hyperfine parameters for hematite, suggesting different degrees of crystallinity and particle size. The hematite found by MB instrument MIMOS II in the outcrop material shows the Morin transition at relatively high temperatures (ca. 250 K) which is an indication of pure and well-crystallized hematite. The source of the hematite in the `Blueberries' as identified by Moessbauer spectroscopy, and also by MiniTES, is not known. These spherules, covering nearly the whole landing site area (Eagle crater, plains, Endurance crater), may be concretions formed in the outcrop

A sup 57 Co Moessbauer emission spectrometric study of some supported CoMo hydrodesulfurization catalysts

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

Veen, J.A.R. van; Hendriks, P.A.J.M.; Beens, H.

1992-01-01

A suite of 11 CoMo/Al{sub 2}O{sub 4} (and one CoMo/SiO{sub 2}) catalysts has been prepared employing four preparation routes, viz. one sequential-impregnation route and three different coimpregnation routes. Speciation of the Co present in the oxidic precursors (octahedral vs tetrahedral Co) and in the activated, sulfided catalysts (CoMoS, Co{sub 9}S{sub 8}, and unsulfided Co) was effected with the aid of {sup 57}Co Moessbauer emission spectroscopy (MES). A linear relation between the thiophene-hydrodesulfurization (HDS) activity and wt% Co-in-CoMoS was observed for each preparation route, but no unique correlation was found to exist. This was traced to the fact that the preparationmore » routes differ in the amount of CoMoS I and CoMoS II they produce in the activated catalyst. Although these two phases differ in specific activity, CoMoS II being twice as active in thiophene HDS as CoMoS I, they cannot be distinguished on the basis of their Moessbauer parameters. It appears that octahedral Co is easier to sulfide than tetrahedral Co, but a substantial fraction of the latter is also found to be capable of entering CoMoS upon sulfidation. The reduced effectiveness of high-loading catalysts is traced to their being prone to CoMoO{sub 4} formation in the calcination step. A rationalization of this behavior is offered.« less

Use of Moessbauer spectroscopy to study reaction products of polyphenols and iron compounds

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

Gust, J.; Suwalski, J.

1994-05-01

Moessbauer spectroscopy was used to study parameters of the reaction products of iron compounds (Fe[sup III]) and polyphenols with hydroxyl (OH) groups in ortho positions. Polyphenols used in the reaction were catechol, pyrogallol, gallic acid, and oak tannin. The Fe-containing compounds were hydrated ferric sulfate (Fe[sub 2][SO[sub 4

The Miniaturized Moessbauer Spectrometers MIMOS II on MER: Four Years of Operation - A Summary

NASA Technical Reports Server (NTRS)

Fleischer, I.; Klingelhoefer, G.; Morris, R. V.; Rodionov, D.; Blumers, M.; Bernhardt, B.; Schroeder, C.; Ming, D. W.; Yen, A. S.; Cohen, B. A.;

Chemostratigraphy and Fe Mineralogy of the Victoria Crater Duck Bay Section: Opportunity APXS and Moessbauer Results

NASA Technical Reports Server (NTRS)

Mittlefehldt, D. W.; Schroeder, C.; Gellert, R.; Klingelhoefer, G.; Jolliff, B. L.; Morris, R. V.

2008-01-01

Meridiani Planum is a vast plain of approximately horizontally bedded sedimentary rocks composed of mixed and reworked basaltic and evaporitic sands containing secondary, diagenetic minerals [e.g., 1-5]. Because bedding planes are subparallel to topography, investigation of contiguous stratigraphy requires examining exposures in impact craters. Early in the mission (sols 130-317), Opportunity was commanded to do detailed study of exposed outcrops in Endurance crater, including the contiguous Karatepe section at the point of ingress. Just over 1000 sols later and roughly 7 km to the south, the rover is being commanded to do a similar study of the Duck Bay section of Victoria crater. Here we report on the preliminary results from the Alpha Particle X-ray Spectrometer (APXS) and Moessbauer instruments.

Moessbauer spectrometer based on UNO-4096-90 accumulator and Elektronika D3-28 microcomputer for simultaneous recording of four spectra

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

Romanov, E.S.; Ivoilov, N.G.

A buffer memory unit and an interface for the UNO-4096-90 accumulator with an Elektronika D3-28 microcomputer are described that allow simultaneous recording of four Moessbauer spectra with zero dead time. For complete elimination of dead time, the pulses from each detector are fed to two buffer counters units, which operate alternately in the write and interrogate modes. This organization of the buffer memory also completely eliminates the effect of the sensors on one another. The use of these circuits does not require any modifications of the computer or accumulator.

Moessbauer spectroscopy analysis of {sup 57}Fe-doped YBaCo{sub 4}O{sub 7+{delta}}: Effects of oxygen intercalation

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

Tsipis, E.V.; Department of Ceramics and Glass Engineering, CICECO, University of Aveiro, 3810-193 Aveiro; Waerenborgh, J.C.

2009-03-15

Moessbauer spectroscopy of layered YBaCo{sub 3.96}Fe{sub 0.04}O{sub 7+{delta}} ({delta}=0.02 and 0.80), where 1% cobalt is substituted with {sup 57}Fe isotope, revealed no evidence of charge ordering at 4-293 K. The predominant state of iron cations was found trivalent, irrespective of their coordination and oxygen stoichiometry variations determined by thermogravimetric analysis. The extremely slow kinetics of isothermal oxidation at 598 K in air, and the changes of Fe{sup 3+} fractions in the alternating triangular and Kagome layers in oxidized YBaCo{sub 3.96}Fe{sub 0.04}O{sub 7.80}, may suggest that oxygen intercalation is accompanied with a substantial structural reconstruction stagnated due to sluggish cation diffusion.more » Decreasing temperature below 75-80 K leads to gradual freezing of the iron magnetic moments in inverse correlation with the content of extra oxygen. The formation of metal-oxygen octahedra and resultant structural distortions extend the temperature range where the paramagnetic and frozen states co-exist, down to 45-50 K. - Graphical abstract: Moessbauer spectroscopy of layered YBaCo{sub 3.96}Fe{sub 0.04}O{sub 7+{delta}} ({delta}=0.02 and 0.80), with 1% {sup 57}Fe isotope substituted for cobalt, revealed no evidence of charge ordering at 4-293 K. The predominant state of iron cations was found trivalent, irrespective of their coordination and oxygen stoichiometry variations determined by thermogravimetric analysis. Decreasing temperature below 75-80 K leads to gradual freezing of the iron magnetic moments in inverse correlation with the content of extra oxygen extending the temperature range where the paramagnetic and frozen states co-exist down to 45-50 K.« less

Development of the Fast Scintillation Detector with Programmable High Voltage Adjustment Suitable for Moessbauer Spectroscopy

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

Prochazka, R.; Frydrych, J.; Pechousek, J.

2010-07-13

This work is focused on a development of a compact fast scintillation detector suitable for Moessbauer spectroscopy (low energy X-ray/{gamma}-ray detection) where high counting rates are inevitable. Optimization of this part was necessary for a reliable function, better time resolution and to avoid a detector pulses pile-up effect. The pile-up effect decreases the measurement performance, significantly depends on the source activity and also on the pulse duration. Our new detection unit includes a fast scintillation crystal YAP:Ce, an R6095 photomultiplier tube, a high voltage power supply socket C9028-01 assembly, an AD5252 digital potentiometer with an I2C interface and an AD8000more » ultra fast operation preamplifier. The main advantages of this solution lie in a short pulse duration (less than 200 ns), stable operation for high activities, programmable gain of the high voltage supply and compact design in the aluminum housing.« less

Copper(II) cyanido-bridged bimetallic nitroprusside-based complexes: Syntheses, X-ray structures, magnetic properties, {sup 57}Fe Moessbauer spectroscopy and thermal studies

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

Travnicek, Zdenek, E-mail: zdenek.travnicek@upol.c; Herchel, Radovan; Mikulik, Jiri

2010-05-15

Three heterobimetallic cyanido-bridged copper(II) nitroprusside-based complexes of the compositions [Cu(tet)Fe(CN){sub 5}NO].H{sub 2}O (1), where tet=N,N'-bis(3-aminopropyl)ethylenediamine, [Cu(hto)Fe(CN){sub 5}NO].2H{sub 2}O (2), where hto=1,3,6,9,11,14-hexaazatricyclo[12.2.1.1{sup 6,9}]octadecane and [Cu(nme){sub 2}Fe(CN){sub 5}NO].H{sub 2}O (3), where nme=N-methylethylenediamine, were synthesized and characterized by elemental analyses, {sup 57}Fe Moessbauer and FTIR spectroscopies, thermal analysis, magnetic measurements and single-crystal X-ray analysis. The products of thermal degradation processes of 2 and 3 were studied by XRD, {sup 57}Fe Moessbauer spectroscopy, SEM and EDS, and they were identified as mixtures of CuFe{sub 2}O{sub 4} and CuO. - Three heterobimetallic cyano-bridged copper(II) nitroprusside-based complexes of the general compositions of [Cu(L)Fe(CN){sub 5}NO].xH{sub 2}O, wheremore » L=N,N'-bis(3-aminopropyl)ethylenediamine (complex 1), 1,3,6,9,11,14-hexaazatricyclo[12.2.1.1{sup 6,9}]-octadecane (complex 2) and N-methylethylenediamine (complex 3), were synthesized, and fully structurally and magnetically characterized. SEM, EDS, XRD and {sup 57}Fe Moessbauer experiments were used for characterization of thermal decomposition products of complexes 2 and 3.« less

An East to West Mineralogical Trend in Mars Exploration Rover Spirit Moessbauer Spectra of Home Plate

NASA Technical Reports Server (NTRS)

Schroder, C.; Di, K.; Morris, R. V.; Klingelhofer, G.; Li, R.

2008-01-01

Home Plate is a light-toned plateau approx.90 m in diameter within the Inner Basin of the Columbia Hills in Gusev crater on Mars. It is the most extensive exposure of layered bedrock encountered by Spirit to date, and it is composed of clastic rocks of moderately altered alkali basalt composition, enriched in some highly volatile elements. Textural observations suggest an explosive origin and geochemical observations favor volcanism, probably a hydrovolcanic explosion [1]. Since it first arrived at Home Plate on sol 744, Spirit has circumnavigated the plateau (Fig. 1) and is now, since sol 1410, resting at its Winter Haven 3 location at the north end of Home Plate. Results: The MER Moessbauer spectrometers determine Fe oxidation states, identify Fe-bearing mineral phases and quantify the distribution of Fe among oxidation states and mineral phases [2]. Moessbauer spectra of Home Plate bedrock were obtained in five different locations from nine different targets (Fig. 1): Barnhill Ace, Posey Manager, and James Cool Papa Bell Stars at the northwest side of Home Plate; Pesapallo, June Emerson, and Elizabeth Emery on the east side; Texas Chili on the south side; Pecan Pie on the west side; and Chanute on the north side.

Moessbauer spectroscopy and scanning electron microscopy of the Murchison meteorite

NASA Technical Reports Server (NTRS)

Brown, Christopher L.; Oliver, Frederick W.; Hammond, Ernest C., Jr.

1989-01-01

Meteorites provide a wealth of information about the solar system's formation, since they have similar building blocks as the Earth's crust but have been virtually unaltered since their formation. Some stony meteorites contain minerals and silicate inclusions, called chondrules, in the matrix. Utilizing Moessbauer spectroscopy, we identified minerals in the Murchison meteorite, a carbonaceous chondritic meteorite, by the gamma ray resonance lines observed. Absorption patterns of the spectra were found due to the minerals olivine and phyllosilicate. We used a scanning electron microscope to describe the structure of the chondrules in the Murchison meteorite. The chondrules were found to be deformed due to weathering of the meteorite. Diameters varied in size from 0.2 to 0.5 mm. Further enhancement of the microscopic imagery using a digital image processor was used to describe the physical characteristics of the inclusions.

Coordination of Fe, Ga and Ge in high pressure glasses by Moessbauer, Raman and X-ray absorption spectroscopy, and geological implications

NASA Technical Reports Server (NTRS)

Fleet, M. E.; Henderson, G. S.; Herzberg, C. T.; Crozier, E. D.; Osborne, M. D.; Scarfe, C. M.

1984-01-01

For some time, it has been recognized that the structure of silicate liquids has a great bearing on such magma properties as viscosity, diffusivity, and thermal expansion and on the extrapolation of thermodynamic quantities outside of the experimentally measurable range. In this connection it is vital to know if pressure imposes changes in melt structure similar to the pressure-induced reconstructive transformations in crystals. In the present study on 1 bar and high pressure glasses, an investigation is conducted regarding the coordination of Fe(3+) in Fe silicate glasses by Moessbauer spectroscopy. Raman spectroscopy is employed to explore the coordinations of Ge(4+) in GeO2 glasses and of Ga(3+) in NaGa silicate glasses, while the coordination of Ga(3+) in NaGaSiO4 glasses is studied with the aid of methods of X-ray absorption spectroscopy.

Coordination of Fe, Ga and Ge in high pressure glasses by Moessbauer, Raman and X-ray absorption spectroscopy, and geological implications

NASA Astrophysics Data System (ADS)

Fleet, M. E.; Herzberg, C. T.; Henderson, G. S.; Crozier, E. D.; Osborne, M. D.; Scarfe, C. M.

1984-07-01

For some time, it has been recognized that the structure of silicate liquids has a great bearing on such magma properties as viscosity, diffusivity, and thermal expansion and on the extrapolation of thermodynamic quantities outside of the experimentally measurable range. In this connection it is vital to know if pressure imposes changes in melt structure similar to the pressure-induced reconstructive transformations in crystals. In the present study on 1 bar and high pressure glasses, an investigation is conducted regarding the coordination of Fe(3+) in Fe silicate glasses by Moessbauer spectroscopy. Raman spectroscopy is employed to explore the coordinations of Ge(4+) in GeO2 glasses and of Ga(3+) in NaGa silicate glasses, while the coordination of Ga(3+) in NaGaSiO4 glasses is studied with the aid of methods of X-ray absorption spectroscopy.

Mineralogy at Gusev Crater and Meridiani Planum from the Moessbauer Spectrometers on the Mars Exploration Rovers

NASA Technical Reports Server (NTRS)

Morris, Richard V.; Klingelhoefer, Goestar

2006-01-01

The Moessbauer spectrometers on the twin MER rovers Spirit and Opportunity have provided significant new information on the distribution of iron among its oxidation states, the identification of the mineralogical composition of iron-bearing phases, and the distribution of iron among those phases for rock and soil at Gusev Crater and Meridiani Planum. The plains of Gusev Crater are dominated by olivine-bearing basalt (approximately Fo(60)) and Fe(3+)/Fe(total)=0.1 - 0.5. The oxide mineral generally present is magnetite. In contrast, initial results for the Columbia Hills are consistent with the presence of hematite and a ferrous iron phase, possibly pyroxene. Gusev spectra also have a ferric doublet (not jarosite) that is tentatively associated with nano-phase ferric oxide. A wider diversity of material is present at Meridiani Planum. Significantly, jarosite-bearing outcrop is present throughout the region, with good exposures in impact craters such as Eagle and Endurance (Fe(3+)/Fe (total) approx. 0.9). The Moessbauer identification of jarosite (a hydroxyl-bearing sulfate mineral) is evidence for aqueous, acid-sulfate processes on Mars. Hematite is observed within the outcrop matrix and in the spheroidal particles (Blueberries) found within the outcrop and as a surface lag. An isolated rock (Bounce Rock) was the only sample at either landing site whose iron-bearing phase was dominated by pyroxene. The basaltic sand in the central portion of Eagle crater, in the intercrater plains, and between slabs of outcrop at both Eagle and Endurance craters is olivine-bearing basalt. The widespread occurrence of olivine-bearing basalt at both MER landing sites implies that physical, rather than chemical, weathering processes dominate at the surface of contemporary Mars.

Decomposition of Potassium Ferrate(VI)(K{sub 2}FeO{sub 4}) and Potassium Ferrate(III)(KFeO{sub 2}): In-situ Moessbauer Spectroscopy Approach

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

Machala, Libor; Zboril, Radek; Sharma, Virender K.

2008-10-28

Moessbauer spectroscopy was shown to be very useful technique studying the mechanism of thermal decomposition or aging processes of the most known ferrate(VI), K{sub 2}FeO{sub 4}. In-situ Moessbauer spectroscopy approach was used to monitor the phase composition during the studied processes. The experimental set-up was designed to perform in-situ measurements at high temperatures and at different air humid conditions at room temperature. The potassium ferrate(III), KFeO{sub 2} was demonstrated to be the primary product of thermal decomposition of K{sub 2}FeO{sub 4}. The KFeO{sub 2} was unstable in a humid air at room temperature and reacted with components of air, H{submore » 2}O and CO{sub 2} to give Fe{sub 2}O{sub 3} nanoparticles and KHCO{sub 3}. The aging kinetics of K{sub 2}FeO{sub 4} and KFeO{sub 2} under humid air were significantly dependent on the relative air humidity.« less

Moessbauer Spectroscopy of Martian and Sverrefjell Carbonates

NASA Technical Reports Server (NTRS)

Agresti, David G.; Morris, Richard V.

2011-01-01

Mars, in its putative "warmer, wetter: early history, could have had a CO2 atmosphere much denser than its current value of <10 mbar. The question of where all this early CO2 has gone has long been debated. Now, several instruments on Mars Exploration Rover (MER) Spirit, including its Moessbauer spectrometer MIMOS II, have identified Mg-Fe carbonate in rock outcrops at Comanche Spur in the Columbia Hills of Gusev Crater. With this finding, carbonate cements in volcanic breccia collected on Sverrefjell Volcano on Spitzbergen Island in the Svalbard Archipelago (Norway) during the AMASE project are mineralogical and possible process analogues of the newly discovered martian carbonate. We report further analyses of Mossbauer spectra from Comanche Spur and discuss their relationship to Mossbauer data acquired on Sverrefjell carbonates. The spectra were velocity calibrated with MERView and fit using MERFit. Instead of the "average temperature" Comanche spectrum (data from all temperature windows summed), we refit the Comanche data for QS within each temperature window, modeling as doublets for Fe2+(carbonate), Fe2+(olivine), and Fe3+(npOx). The temperature dependences of QS for the Comanche carbonate and for a low-Ca carbonate from Chocolate Pots in Yellowstone National Park (YNP) are shown; they are the same within error. For Comanche carbonate summed over 210-270 K, (CS, QS) = (1.23, 1.95) mm/s. The value of QS for Sverrefjell carbonate at 295 K, (CS, QS) = (1.25, 1.87) mm/s, is also plotted, and the plot shows that the QS for the Sverrefjell carbonate agrees within error with the Comanche data extrapolated to 295 K. This agreement is additional evidence that the Sverrefjell carbonates are Mossbauer analogues for the Comanche carbonates, and that both carbonates might have precipitated from solutions that became carbonate rich by passing through buried carbonate deposits.

Fe-Bearing Phases Identified by the Moessbauer Spectrometers on the Mars Exploration Rovers: An Overview

NASA Technical Reports Server (NTRS)

Morris, R. V.; Klingelhoefer, G.; Rodionov, D.; Yen, A.; Gellert, R.

2006-01-01

The twin Mars Exploration Rovers Spirit and Opportunity have explored the martian surface at Gusev Crater (GC) and Meridiani Planum (MP), respectively, for about two Earth years. The Moessbauer (MB) spectrometers on both rovers have analyzed an aggregate of 200 surface targets and have returned to Earth information on the oxidation state of iron, the mineralogical composition of Febearing phases, and the distribution of Fe among oxidation states and phases at the two landing sites [1-7]. To date, 15 component subspectra (10 doublets and 5 sextets) have been identified and most have been assigned to mineralogical compositions. Two subspectra are assigned to phases (jarosite and goethite) that are marker minerals for aqueous processes because they contain hydroxide anion in their structures. In this paper, we give an overview of the Febearing phases identified and their distributions at Gusev crater and Meridiani Planum.

Fe-Bearing Phases Indentified by the Moessbauer Spectrometers on the Mars Exploration Rovers: An Overview

NASA Technical Reports Server (NTRS)

Morris, R. V.; Klingelhoefer, G.; Ming, D. W.; Schroeder, C.; Rodionov, D.; Yen, A.; Gellert, R.

2006-01-01

The twin Mars Exploration Rovers Spirit and Opportunity have explored the martian surface at Gusev Crater (GC) and Meridiani Planum (MP), respectively, for about two Earth years. The Moessbauer (MB) spectrometers on both rovers have analyzed an aggregate of approx.200 surface targets and have returned to Earth information on the oxidation state of iron, the mineralogical composition of Fe-bearing phases, and the distribution of Fe among oxidation states and phases at the two landing sites [1-7]. To date, 15 component subspectra (10 doublets and 5 sextets) have been identified and most have been assigned to mineralogical compositions. Two subspectra are assigned to phases (jarosite and goethite) that are marker minerals for aqueous processes because they contain hydroxide anion in their structures. In this paper, we give an overview of the Febearing phases identified and their distributions at Gusev crater and Meridiani Planum.

Moessbauer and Electron Microprobe Studies of Density Separates of Martian Nakhlite Mil03346: Implications for Interpretation of Moessbauer Spectra Acquired by the Mars Exploration Rovers

NASA Technical Reports Server (NTRS)

Morris, R. V.; McKay, G. A.; Agresti, D. G.; Li, Loan

2008-01-01

Martian meteorite MIL03346 is described as an augite-rich cumulate rock with approx.80%, approx.3%, and approx.21% modal phase proportions of augite (CPX), olivine and glassy mesostasis, respectively, and is classified as a nakhlite [1]. The Mossbauer spectrum for whole rock (WR) MIL 03346 is unusual for Martian meteorites in that it has a distinct magnetite subspectrum (7% subspectral area) [2]. The meteorite also has products of pre-terrestrial aqueous alteration ("iddingsite") that is associated primarily with the basaltic glass and olivine. The Mossbauer spectrometers on the Mars Exploration Rovers have measured the Fe oxidation state and the Fe mineralogical composition of rocks and soils on the planet s surface since their landing in Gusev Crater and Meridiani Planum in January, 2004 [3,4]. The MIL 03346 meteorite provides an opportunity to "ground truth" or refine Fe phase identifications. This is particularly the case for the so-called "nanophase ferric oxide" (npOx) component. NpOx is a generic name for a ferric rich product of oxidative alteration. On Earth, where we can take samples apart and study individual phases, examples of npOx include ferrihydrite, schwertmannite, akagaaneite, and superparamagnetic (small particle) goethite and hematite. It is also possible for ferric iron to be associated to some unknown extent with igneous phases like pyroxene. We report here an electron microprobe (EMPA) and Moessbauer (MB) study of density separates of MIL 03346. The same separates were used for isotopic studies by [5]. Experimental techniques are described by [6,7].

Innovative instrumentation for mineralogical and elemental analyses of solid extraterrestrial surfaces: The Backscatter Moessbauer Spectrometer/X Ray Fluorescence analyzer (BaMS/XRF)

NASA Technical Reports Server (NTRS)

Shelfer, T. D.; Morris, Richard V.; Nguyen, T.; Agresti, D. G.; Wills, E. L.

1994-01-01

We have developed a four-detector research-grade backscatter Moessbauer spectrometer (BaMS) instrument with low resolution x-ray fluorescence analysis (XRF) capability. A flight-qualified instrument based on this design would be suitable for use on missions to the surfaces of solid solar-system objects (Moon, Mars, asteroids, etc.). Target specifications for the flight instrument are as follows: mass less than 500 g; volumes less than 300 cu cm; and power less than 2 W. The BaMS/XRF instrument would provide data on the oxidation state of iron and its distribution among iron-bearing mineralogies and elemental composition information. This data is a primary concern for the characterization of extraterrestrial surface materials.

On previous and present investigations of resonance gamma-ray interaction with nuclei at the Institute of Theoretical and Experimental Physics (ITEP, Moscow)

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

Davydov, A. V.

A brief survey of theoretical and experimental work that is devoted to studying the resonance absorption and scattering of gamma rays by nuclei and which was initiated at the Institute of Theoretical and Experimental Physics (ITEP, Moscow) in the 1950s and has been continued to date is given. Investigations of various versions of interaction in beta decay, magnetic-field-perturbed angular distributions of resonantly scattered gamma rays, the problem of the Moessbauer gamma resonance of long-lived isomeric states of nuclei, and the resonance scattering of annihilation photons by nuclei are described.

Iron Mineralogy and Aqueous Alteration on Mars from the MER Moessbauer Spectrometers. Chapter 15

NASA Technical Reports Server (NTRS)

Morris, Richard V.; Klingelhoefer, Goestar

2007-01-01

The twin Mars Exploration Rovers Spirit (Gusev crater) and Opportunity (Meridiani Planum) used MIMOS II Moessbauer spectrometers to analyze martian surface materials in the first application of extraterrestrial Moessbauer spectroscopy. The instruments acquired spectra that identified the speciation of Fe according to oxidation state, coordination state, and mineralogical composition and provided quantitative information about the distribution of Fe among oxidation states, coordination states, and Fe-bearing phases. A total of 12 unique Fe-bearing phases were identified: Fe(2+) in olivine, pyroxene, and ilmenite; Fe(2+) and Fe(3+) in magnetite and chromite; Fe(3+) in nanophase ferric oxide (npOx), hematite, goethite, jarosite, an unassigned Fe3+ sulfate, and an unassigned Fe(3+) phase associated with jarosite; and Fe(0) in kamacite. Weakly altered basalts at Gusev crater (SO3 = 2.5 +/- 1.4 wt.% and Fe(3+)/Fe(sub T) = 0.24 +/- 0.11) are widespread on the Gusev plains and occur in less abundance on West Spur and Husband Hill in the Columbia Hills. Altered low-S rocks (SO3 = 5.2 +/- 2.0 wt.% and Fe(3+)/Fe(sub T) = 0.63 +/- 0.18) are the most common type of rock in the Columbia Hills. Ilm-bearing, weakly altered basalts were detected only in the Columbia Hills, as was the only occurrence of chromite in an altered low-S rock named Assemblee. Altered high-S rocks (SO3 > 14.2 wt.% and Fe(3+)/Fe(sub T) = 0.83 +/- 0.05) are the outcrop rocks of the ubiquitous Burns formation at Meridiani Planum. Two Fe(0)-bearing rocks at Meridiani Planum (Barberton and Heat Shield Rock) are meteorites. Laguna Class soil is weakly altered (SO3 = 6 +/- 2 wt.% and Fe(3+)/Fe(sub T) = 0.29 +/- 0.08) and widely distributed at both Gusev crater and Meridiani Planum, implying efficient global mixing processes or a global distribution of precursor rocks with comparable Fe mineralogical compositions. Paso Robles Class soil is heavily altered (SO3 approx. 31 wt.% and Fe(3+)/Fe(sub T) = 0.83 +/- 0

Moessbauer Spectroscopy for Lunar Resource Assessment: Measurement of Mineralogy and Soil Maturity

NASA Technical Reports Server (NTRS)

Morris, R. V.; Agresti, D. G.; Shelfer, T. D.; Pimperl, M. M.; Shen, M.-H.; Gibson, M. A.; Wills, E. L.

1992-01-01

First-order assessment of lunar soil as a resource includes measurement of its mineralogy and maturity. Soils in which the mineral ilmenite is present in high concentrations are desirable feedstock for the production of oxygen at a lunar base. The maturity of lunar soils is a measure of their relative residence time in the upper 1 mm of the lunar surface. Increasing maturity implies increasing load of solar wind species (e.g., N, H, and He-3), decreasing mean grain size, and increasing glass content. All these physicochemical properties that vary in a regular way with maturity are important parameters for assessing lunar soil as a resource. For example, He-3 can be extracted and potentially used for nuclear fusion. A commonly used index for lunar soil maturity is I(sub s)/FeO, which is the concentration of fine-grained metal determined by ferromagnetic resonance (I(sub s)) normalized to the total iron content (as FeO). I(sub s)/FeO has been measured for virtually every soil returned by the Apollo and Luna missions to the Moon. Because the technique is sensitive to both oxidation state and mineralogy, iron Moessbauer spectroscopy (FeMS) is a viable technique for in situ lunar resource assessment. Its utility for mineralogy is apparent from examination of published FeMS data for lunar samples. From the data published, it can be inferred that FeMS data can also be used to determine soil maturity. The use of FeMS to determine mineralogy and maturity and progress on development of a FeMS instrument for lunar surface use are discussed.

Elasticity and magnetocaloric effect in MnFe 4Si 3

DOE PAGES

Herlitschke, Marcus; Klobes, B.; Sergueev, I.; ...

2016-03-16

The room temperature magnetocaloric material MnFe 4Si 3 was investigated with nuclear inelastic scattering (NIS) and resonant ultrasound spectroscopy (RUS) at different temperatures and applied magnetic fields in order to assess the infuence of the magnetic transition and the magnetocaloric effect on the lattice dynamics. The NIS data give access to phonons with energies above 3 meV, whereas RUS probes the elasticity of the material in the MHz frequency range and thus low energy, ~5 neV, phonon modes. A significant infuence of the magnetic transition on the lattice dynamics is observed only in the low energy region. Here, MnFe 4Simore » 3 and other compounds in the Mn 5-xFe xSi 3 series were also investigated with vibrating sample magnetometry, resistivity measurements and Moessbauer spectroscopy in order to study the magnetic transitions and to complement the obtained results on the lattice dynamics.« less

The Incredible Diversity of Fe-bearing Phases at Gusev Crater, Mars, According to the Mars Exploration Rover Moessbauer Spectrometer

NASA Technical Reports Server (NTRS)

Morris, R. V.; Klingelhoefer, G.; Schroeder, C.; Rodionov, D. S.; Ming, D. W.; Yen, A.

2006-01-01

The Mars Exploration Rover (MER) Spirit landed on the plains of Gusev Crater on 4 January 2004. One primary scientific objective for the mission is to characterize the mineralogical and elemental composition of surface materials, searching for evidence of water and clues for assessing past and current climates and their suitability for life [1]. The role of the Moessbauer (MB) spectrometer on Spirit is to provide quantitative information about the distribution of Fe among its oxidation and coordination states, identification of Fe-bearing phases, and relative distribution of Fe among those phases. The speciation and distribution of Fe in Martian rock and soil constrains the primary rock types, redox conditions under which primary minerals crystallized, the extent of alteration and weathering, the type of alteration and weathering products, and the processes and environmental conditions for alteration and weathering. In this abstract, we discuss the incredible diversity of Fe-bearing phases detected by Spirit s MB instrument during its first 540 sols of exploration at Gusev crater [2,3].

Anomalous Moessbauer Fraction in Superparamagnetic Systems.

NASA Astrophysics Data System (ADS)

Mohie-Eldin, Mohie-Eldin Yehia

The biological molecule ferritin and its proven synthetic counterpart polysaccharide iron complex (P.I.C.) have been shown to contain small (<100 ^circ in diameter) antiferromagnetic cores at their centers. Mossbauer studies of these molecules have revealed an anomalous drop in the Mossbauer fraction (f-factor) as the temperature rises above 30^ circK for mammalian ferritin and 60 ^circK for P.I.C. Above the blocking temperature, superparamagnetic relaxation results in the disappearance of hyperfine splitting. This thesis investigates and attempts to resolve this Lamb-Mossbauer f-Factor anomaly in these superparamagnetically relaxing systems. Chapter I deals with a basic review of theories of Mossbauer spectroscopy and superparamagnetism. The analogies in the composition of the two molecules is examined in Chapter II. The long range order technique of magnetization measurements is used in Chapter III to compare magnetic properties of both molecules and to verify the suggestion that the P.I.C. molecule is a good "biomimic" to ferritin based on the identification of ferrihydrite as the major mineral in both, by short range probing techniques such as X-ray diffraction. The anomaly is confirmed in P.I.C.'s Mossbauer spectra in Chapter IV. Different absorbers are used to experimentally investigate the absorber thickness effect on the Mossbauer spectra. The anomaly persists for thin absorbers. Also in Chapter V, data that is treated with FFT procedures to eliminate the thickness effect still exhibit this anomaly. We then investigated the effect of superparamagnetic relaxation on the f-factor. In Chapter VI, spin-lattice relaxation was excluded based upon a calculation of the rate of energy transfer from the spin system to the lattice. We introduce a theory in Chapter VII based on the following process as a plausible explanation of the anomaly: Superparamagnetic relaxation brings about a dynamical displacement of the Mossbauer nucleus through magnetostriction. These

The 2010 ILSO-ISRU Field Test at Mauna Kea, Hawaii: Results from the Miniaturised Mossbauer Spectrometers Mimos II and Mimos IIA

NASA Technical Reports Server (NTRS)

Klingelhoefer, G.; Morris, R. V.; Blumers, M.; Bernhardt, B.; Graff, T.

2011-01-01

For the advanced Moessbauer instrument MIMOS IIA, the new detector technologies and electronic components increase sensitivity and performance significantly. In combination with the high energy resolution of the SDD it is possible to perform X-ray fluorescence analysis simultaneously to Moessbauer spectroscopy. In addition to the Fe-mineralogy, information on the sample's elemental composition will be gathered. The ISRU 2010 field campaign demonstrated that in-situ Moessbauer spectroscopy is an effective tool for both science and feedstock exploration and process monitoring. Engineering tests showed that a compact nickel metal hydride battery provided sufficient power for over 12 hr of continuous operation for the MIMOS instruments.

Mineralogical diversity (spectral reflectance and Moessbauer data) in compositionally similar impact melt rocks from Manicouagan Crater, Canada

NASA Technical Reports Server (NTRS)

Morris, R. V.; Bell, J. F., III; Golden, D. C.; Lauer, H. V., Jr.

1993-01-01

Meteoritic impacts under oxidizing surface conditions occur on both earth and Mars. Oxidative alteration of impact melt sheets is reported at several terrestrial impact structures including Manicouagan, West Clearwater Lake, and the Ries Basin. A number of studies have advocated that a significant fraction of Martian soil may consist of erosional products of oxidatively altered impact melt sheets. If so, the signature of the Fe-bearing mineralogies formed by the process may be present in visible and near infrared reflectivity data for the Martian surface. Of concern is what mineral assemblages form in impact melt sheets produced under oxidizing conditions and what their spectral signatures are. Spectral and Moessbauer data for 19 powder samples of impact melt rock from Manicouagan Crater are reported. Results show for naturally occurring materials that composite hematite-pyroxene bands have minima in the 910-nm region. Thus many of the anomalous Phobos-2 spectra, characterized by a shallow band minimum in the near-IR whose position varies between approximately 850 and 1000 nm, can be explained by assemblages whose endmembers (hematite and pyroxene) are accepted to be present on Mars. Furthermore, results show that a mineralogically diverse suite of rocks can be generated at essentially constant composition, which implies that variations in Martian surface mineralogy do not necessarily imply variations in chemical composition.

Nuclear resonance scattering of synchrotron radiation as a unique electronic, structural and thermodynamic probe

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

Alp, E. Ercan; Sturhahn, Wolfgang; Toellner, Thomas S.

2012-05-09

Discovery of Moessbauer effect in a nuclear transition was a remarkable development. It revealed how long-lived nuclear states with relatively low energies in the kiloelectron volt (keV) region can be excited without recoil. This new effect had a unique feature involving a coupling between nuclear physics and solid-state physics, both in terms of physics and sociology. Physics coupling originates from the fact that recoilless emission and absorption or resonance is only possible if the requirement that nuclei have to be bound in a lattice with quantized vibrational states is fulfilled, and that the finite electron density on the nucleus couplesmore » to nuclear degrees of freedom leading to hyperfine interactions. thus, Moessbauer spectroscopy allows peering into solid-state effects using unique nuclear transitions. Sociological aspects of this coupling had been equally startling and fruitful. The interaction between diverse scientific communities, who learned to use Moessbauer spectroscopy proved to be very valuable. For example, biologists, geologists, chemists, physics, materials scientists, and archeologists, all sharing a common spectroscopic technique, also learned to appreciate the beauty and intricacies of each other's fields. As a laboratory-based technique, Moessbauer spectroscopy matured by the end of the 1970s. Further exciting developments took place when accelerator-based techniques were employed, like synchrotron radiation or 'in-beam'Moessbauer experiments with implanted radioactive ions. More recently, two Moessbauer spectrometers on the surface of the Mars kept the technique vibrant and viable up until present time. In this chapter, the authors look into some of the unique aspects of nuclear resonance excited with synchrotron radiation as a probe of condensed matter, including magnetism, valence, vibrations, and lattice dynamics, and review the development of nuclear resonance inelastic x-ray scattering (NRIXS) and synchrotron Moessbauer

Effectiveness of onsite focused investigations : [analysis brief].

DOT National Transportation Integrated Search

2016-03-01

This analysis assesses the effectiveness of onsite : focused investigations of motor carriers, relative to : onsite comprehensive investigations, conducted during : calendar years 2011 and 2012. Effectiveness was : measured by examining trends in mot...

Effect of oxygen impurities on properties of the ternary superconductor SnMo/sub 6/S/sub 8/: Extended x-ray-absorption fine-structure determination of bond distances and local-density cluster calculations

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

Guenzburger, D.; Ellis, D.E.; Montano, P.A.

1985-10-01

Electronic structure calculations were performed for clusters representing the Chevrel-phase SnMo/sub 6/S/sub 8/, with and without oxygen doping. In order to obtain the local structure around the Sn atom, extended x-ray-absorption fine-structure (EXAFS) measurements were made with synchro- tron radiation. The interatomic distances obtained experimentally were used in the calculations. The effect of oxygen doping on the Moessbauer isomer shift and quadrupole splitting values of /sup 119/Sn was investigated theoretically and compared with reported experimental values. The effect of oxygen substitution on the density of states at the Fermi energy of the (Mo/sub 6/S/sub 8/)/sup 2 -/ cluster was alsomore » studied. The results suggest that oxygen doping does not alter significantly the electronic structure of SnMo/sub 6/S/sub 8/.« less

Effect of cycled combustion ageing on a cordierite burner plate

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

Garcia, Eugenio; Gancedo, J. Ramon; Gracia, Mercedes, E-mail: rocgracia@iqfr.csic.es

2010-11-15

A combination of {sup 57}Fe-Moessbauer spectroscopy and X-ray Powder Diffraction analysis has been employed to study modifications in chemical and mechanical stability occurring in a cordierite burner aged under combustion conditions which simulate the working of domestic boilers. Moessbauer study shows that Fe is distributed into the structural sites of the cordierite lattice as Fe{sup 2+} and Fe{sup 3+} ions located mostly at octahedral sites. Ferric oxide impurities, mainly hematite, are also present in the starting cordierite material accounting for {approx_equal}40% of the total iron phases. From Moessbauer and X-ray diffraction data it can be deduced that, under the combustionmore » conditions used, new crystalline phases were formed, some of the substitutional Fe{sup 3+} ions existing in the cordierite lattice were reduced to Fe{sup 2+}, and ferric oxides underwent a sintering process which results in hematite with higher particle size. All these findings were detected in the burner zone located in the proximity of the flame and were related to possible chemical reactions which might explain the observed deterioration of the burner material. Research Highlights: {yields}Depth profile analyses used as a probe to understand changes in refractory structure. {yields}All changes take place in the uppermost surface of the burner, close to the flame. {yields}Reduction to Fe{sup 2+} of substitutional Fe{sup 3+} ions and partial cordierite decomposition. {yields}Heating-cooling cycling induces a sintering of the existing iron oxide particles. {yields}Chemical changes can explain the alterations observed in the material microstructure.« less

Investigation of dynamic ground effect

NASA Technical Reports Server (NTRS)

Chang, Ray Chung; Muirhead, Vincent U.

1987-01-01

An experimental investigation of dynamic ground effect was conducted in the Univ. of Kansas wind tunnel using delta wings of 60, 70, 75 deg sweep; the XB-70 wing; and the F-104A wing. Both static and dynamic tests were made. Test data were compared to other test data, including dynamic flight test data of the XB-70 and F-104A. Limited flow visualization test were conducted. A significant dynamic effect was found for highly swept delta wings.

Effects of gamma-sterilization on the physicochemical properties of natural sediments

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

Bank, Tracy L; Madden, Andrew; Baldwin, Mark E

2008-06-01

Batch U(VI) sorption/reduction experiments were completed on sterilized and non-sterilized sediment samples to elucidate biological and geochemical reduction mechanisms. Results from X-ray absorption near-edge structure (XANES) spectroscopy revealed that {gamma}-sterilized sediments were actually better sorbents of U(VI), despite the absence of any measurable biological activity. These results indicate that {gamma}-irradiation induced significant physico-chemical changes in the sediment which is contrary to numerous other studies identifying {gamma}-sterilization as an effective and minimally invasive technique. To identify the extent and method of alteration of the soil as a result of {gamma}-sterilization, untreated soil samples, physically separated size fractions, and chemically extracted fractionsmore » of the soil were analyzed pre- and post-sterilization. The effects of sterilization on mineralogy, pH, natural organic matter (NOM), cation exchange capacity (CEC), and iron oxidation state were determined. Results indicated that major mineralogy of the clay and whole sediment samples was unchanged. Sediment pH decreased only slightly with {gamma}-irradiation; however, irradiation produced a significant decrease in CEC of the untreated sediments and affected both the organic and inorganic fractions. Moessbauer spectra of non-sterile and {gamma}-sterilized sediments measured more reduced iron present in {gamma}-sterilized sediments compared to non-sterile samples. Our results suggest that sterilization by {gamma}-irradiation induced iron reduction that may have increased the sorption and/or reduction of U(VI) onto these sediments. However, Moessbauer and batch sorption data are somewhat contradictory, the former indicates that the iron oxide or iron hydroxide minerals are more significantly reduced while the later indicates that reduced clay minerals account for greater sorption of U(VI).« less

Sampling Martian Soil

NASA Technical Reports Server (NTRS)

2004-01-01

Scientists were using the Moessbauer spectrometer on NASA's Mars Exploration Rover Spirit when something unexpected happened. The instrument's contact ring had been placed onto the ground as a reference point for placement of another instrument, the alpha particle X-ray spectrometer, for analyzing the soil. After Spirit removed the Moessbauer from the target, the rover's microscopic imager revealed a gap in the imprint left behind in the soil. The gap, about a centimeter wide (less than half an inch), is visible on the left side of this mosaic of images. Scientists concluded that a small chunk of soil probably adhered to the contact ring on the front surface of the Moessbauer. Before anyone saw that soil may have adhered to the Moessbauer, that instrument was placed to analyze martian dust collected by a magnet on the rover. The team plans to take images to see if any soil is still attached to the Moessbauer. Spirit took these images on the rover's 240th martian day, or sol (Sept. 4, 2004).

Investigating the Binary Offset Effect in the STIS CCD

NASA Astrophysics Data System (ADS)

Debes, John H.; Lockwood, Sean A.

2018-05-01

Recently, Boone et al., (2018) presented the "Binary Offset Effect" for the SNIFS instrument, which uses a CCD detector. The source of this uncertainty is related to the analog-to-digital readout process, which converts the analog electronic signal of the detector into a digital number as represented by binary bits. The Binary Offset Effect is due to cross-talk between the digital conversion process for a source or driver pixel and pixels read out after the driver. In the course of Boone et al.'s experimentation with this effect they identified a similar effect with the STIS CCD. The STIS team has independently investigated the Binary Offset Effect for a range of bias images currently used for scientific observations, broadly confirming that the effect exists. However, our preliminary investigation suggests that the impact is smaller than reported in Boone et al. (2018) for biases taken with Amplifier=D and GAIN=1, and a lesser effect exists for Amplifier=D and GAIN=4. There is a hint that the effect is time variable for the detector. We broadly assess the potential impact of this effect and make recommendations both for users and future directions of investigation.

Lunar sample analysis

NASA Technical Reports Server (NTRS)

Housley, R. M.

1978-01-01

Flameless atomic abosrption, X-ray photoemission spectroscopy, ferromagnetic resonance, scanning electron microscopy, and Moessbauer spectroscopy were used to investigate the evolution of the lunar regolith, the transport of volatile trace metals, and the surface composition of lunar samples. The development of a model for lunar volcanic eruptions is also discussed.

Effects of Sterilization on the Physico-Chemical Properties of Natural Sediments From the Oak Ridge Reservation

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

Bank, T.L.; Kukkadapu, R.K.; Madden, A.S.

2009-04-29

Batch U(VI) sorption/reduction experiments were completed on sterilized and non-sterilized sediment samples to elucidate biological and geochemical reduction mechanisms. Results from X-ray absorption near-edge structure (XANES) spectroscopy revealed that {gamma}-sterilized sediments were actually better sorbents of U(VI), despite the absence of any measurable biological activity. These results indicate that {gamma}-irradiation induced significant physico-chemical changes in the sediment which is contrary to numerous other studies identifying {gamma}-sterilization as an effective and minimally invasive technique. To identify the extent and method of alteration of the soil as a result of {gamma}-sterilization, untreated soil samples, physically separated size fractions, and chemically extracted fractionsmore » of the soil were analyzed pre- and post-sterilization. The effects of sterilization on mineralogy, pH, natural organic matter (NOM), cation exchange capacity (CEC), and iron oxidation state were determined. Results indicated that major mineralogy of the clay and whole sediment samples was unchanged. Sediment pH decreased only slightly with {gamma}-irradiation; however, irradiation produced a significant decrease in CEC of the untreated sediments and affected both the organic and inorganic fractions. Moessbauer spectra of non-sterile and {gamma}-sterilized sediments measured more reduced iron present in {gamma}-sterilized sediments compared to non-sterile samples. Our results suggest that sterilization by {gamma}-irradiation induced iron reduction that may have increased the sorption and/or reduction of U(VI) onto these sediments. However, Moessbauer and batch sorption data are somewhat contradictory, the former indicates that the iron oxide or iron hydroxide minerals are more significantly reduced while the later indicates that reduced clay minerals account for greater sorption of U(VI).« less

Sampling Martian Soil (3-D)

NASA Technical Reports Server (NTRS)

2004-01-01

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2

Scientists were using the Moessbauer spectrometer on NASA's Mars Exploration Rover Spirit when something unexpected happened. The instrument's contact ring had been placed onto the ground as a reference point for placement of another instrument, the alpha particle X-ray spectrometer, for analyzing the soil. After Spirit removed the Moessbauer from the target, the rover's microscopic imager revealed a gap in the imprint left behind in the soil. The gap, about a centimeter wide (less than half an inch), is visible on the left side of this stereo view. Scientists concluded that a small chunk of soil probably adhered to the contact ring on the front surface of the Moessbauer. Before anyone saw that soil may have adhered to the Moessbauer, that instrument was placed to analyze martian dust collected by a magnet on the rover. The team plans to take images to see if any soil is still attached to the Moessbauer. Spirit took these images on the rover's 240th martian day, or sol (Sept. 4, 2004).

Figure 1 is the left-eye view of a stereo pair and Figure 2 is the right-eye view of a stereo pair.

Iron-oxide Aerogel and Xerogel Catalyst Formulations: Characterization by 57Fe Mössbauer and XAFS Spectroscopies

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

Huggins, F.; Bali, S; Huffman, G

2010-01-01

Iron in various iron-oxide aerogel and xerogel catalyst formulations ({ge}85% Fe{sub 2}O{sub 3}; {le}10% K, Co, Cu, or Pd) developed for possible use in Fischer-Tropsch synthesis (FTS) or the water-gas-shift (WGS) reaction has been examined by {sup 57}Fe Moessbauer spectroscopy. The seventeen samples consisted of both as-prepared and calcined aerogels and xerogels and their products after use as catalysts for FTS or the WGS reaction. Complementary XAFS spectra were obtained on the occurrence of the secondary elements in some of the same materials. A broad, slightly asymmetric, two-peak Moessbauer spectrum was obtained from the different as-prepared and calcined catalyst formulationsmore » in the majority of cases. Such spectra could only be satisfactorily fit with three quadrupole doublet components, but no systematic trends in the isomer shift and quadrupole splitting parameters and area ratios of the individual components could be discerned that reflected variations in the composition or preparation of the aerogel or xerogel materials. However, significant reductions were noted in the Moessbauer effective thickness (recoilless absorption effect per unit mass of iron) parameter, {chi}{sub eff}/g, determined at room temperature, for aerogels and xerogels compared to bulk iron oxides, reflecting the openness and lack of rigidity of the aerogel and xerogel structures. Moessbauer measurements for two aerogels over the range from 15 to 292 K confirmed the greatly diminished nature of this parameter at room temperature. Major increases in the effective thickness parameter were observed when the open structure of the aerogel or xerogel collapsed during calcination resulting in the formation of iron oxides (hematite, spinel ferrite). Similar structural changes were indicated by increases in this parameter after use of iron-oxide aerogels as catalysts for FTS or the WGS reaction, during which the iron-oxide aerogel was converted to a mixture of nonstoichiometric

Analytical methods in environmental effects-directed investigations of effluents.

PubMed

Hewitt, L Mark; Marvin, Chris H

2005-05-01

Effluent discharges are released into aquatic environments as complex mixtures for which there is commonly either no knowledge of the toxic components or a lack of understanding of how known toxicants interact with other effluent components. Effects-directed investigations consist of chemical extraction and iterative fractionation steps directed by a biological endpoint that is designed to permit the identification or characterization of the chemical classes or compounds in a complex mixture responsible for the observed biological activity. Our review of the literature on effects-directed analyses of effluents for non-mutagenic as well as mutagenic endpoints showed that common extraction and concentration methods have been used. Since the mid-1980s, the methods have evolved from the use of XAD resins to C18 solid-phase extraction (SPE). Blue cotton, blue rayon, and blue chitin have been used specifically for investigations of mutagenic activity where polycyclic compounds were involved or suspected. After isolation, subsequent fractionations have been accomplished using SPE or a high-pressure liquid chromatography (HPLC) system commonly fitted with a C18 reverse-phase column. Substances in active fractions are characterized by gas chromatography/mass spectrometry (GC-MS) and/or other spectrometric techniques for identification. LC-MS methods have been developed for difficult-to-analyze polar substances identified from effects-directed studies, but the potential for LC-MS to identify unknown polar compounds has yet to be fully realized. Salmonella-based assays (some miniaturized) have been coupled with fractionation methods for most studies aimed at identifying mutagenic fractions and chemical classes in mixtures. Effects-directed investigations of mutagens have focused mostly on drinking water and sewage, whereas extensive investigations of non-mutagenic effects have also included runoff, pesticides, and pulp mill effluents. The success of effects

Speech Effort Measurement and Stuttering: Investigating the Chorus Reading Effect

ERIC Educational Resources Information Center

Ingham, Roger J.; Warner, Allison; Byrd, Anne; Cotton, John

2006-01-01

Purpose: The purpose of this study was to investigate chorus reading's (CR's) effect on speech effort during oral reading by adult stuttering speakers and control participants. The effect of a speech effort measurement highlighting strategy was also investigated. Method: Twelve persistent stuttering (PS) adults and 12 normally fluent control…

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

Hu Qiang; Zeng Xierong; Shenzhen Key Laboratory of Special Functional Materials, Shenzhen 518060

This paper reports the observation of the clear Invar effects of (Fe{sub 71.2}B{sub 24}Y{sub 4.8}){sub 96}Nb{sub 4} bulk metallic glass. The Invar effects of (Fe{sub 71.2}B{sub 24}Y{sub 4.8}){sub 96}Nb{sub 4} alloys in different structural states are also investigated in situ through cyclic thermal dilation tests at different cyclic temperatures. The results show that these Invar effects are strengthened in the relaxation amorphous state, weakened in the nanocrystalline state, and absent in the complete crystalline state. X-ray diffraction and Moessbauer spectroscopy demonstrate that the structural influences on Invar effects can be explained by the different local atomic arrangements around Fe atomsmore » in different structural states.« less

Hall-effect Thruster Channel Surface Properties Investigation (PREPRINT)

DTIC Science & Technology

2011-03-03

Article 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Hall-effect Thruster Channel Surface Properties Investigation 5b...13. SUPPLEMENTARY NOTES For publication in the AIAA Journal of Propulsion and Power. 14. ABSTRACT Surface properties of Hall-effect thruster...incorporated into thruster simulations, and these models must account for evolution of channel surface properties due to thruster operation. Results from

Investigation of Post-mortem Tissue Effects Using Long-time Decorrelation Ultrasound

NASA Astrophysics Data System (ADS)

Csány, Gergely; Balogh, Lajos; Gyöngy, Miklós

Decorrelation ultrasound is being increasingly used to investigate long-term biological phenomena. In the current work, ultrasound image sequences of mice who did not survive anesthesia (in a separate investigation) were analyzed and post-mortem tissue effects were observed via decorrelation calculation. A method was developed to obtain a quantitative parameter characterizing the rate of decorrelation. The results show that ultrasound decorrelation imaging is an effective method of observing post-mortem tissue effects and point to further studies elucidating the mechanism behind these effects.

To the problem about the origin of lunar maria and continents (Moessbauer investigations)

NASA Technical Reports Server (NTRS)

Malysheva, T. V.

1977-01-01

A comparative study of Mossbauer spectra of regolith returned by the Luna 16 and Luna 20 spacecraft is presented. The Mossbauer spectra of the mare regolith differs significantly for all fractions from the spectra for the same fractions of continental regolith. The total quantity of iron is 1.85 times greater in the mare regolith. There is 2.4 times less olivine in the mare region than in the continental region. The pyroxene component of the mare regolith is less homogeneous in composition (contains more augite and glass) and is present in larger quantities. Ilmenite was found only in the mare regolith. In the continental region, the predominant titanium-containing phase is ulvospinel. The mare regolith contains more metallic iron, which is more finely dispersed and contains less nickel. Troilite is found in the maria region. Based on these differences, it is concluded that the formation of continental rocks occurred at an earlier stage of crystallization from the melt and at higher temperatures and higher partial pressures of oxygen. The mare basalts crystallized from a more reduced magma, apparently in a later process.

19 CFR 206.55 - Investigations to evaluate the effectiveness of relief.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Investigations to evaluate the effectiveness of relief. 206.55 Section 206.55 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION NONADJUDICATIVE INVESTIGATIONS INVESTIGATIONS RELATING TO GLOBAL AND BILATERAL SAFEGUARD ACTIONS, MARKET DISRUPTION, TRADE...

New selection effect in statistical investigations of supernova remnants

NASA Astrophysics Data System (ADS)

Allakhverdiev, A. O.; Guseinov, O. Kh.; Kasumov, F. K.

1986-01-01

The influence of H II regions on the parameters of supernova remnants (SNR) is investigated. It has been shown that the projection of such regions on the SNRs leads to: a) local changes of morphological structure of young shell-type SNRs and b) considerable distortions of integral parameters of evolved shell-type SNRs (with D > 10 pc) and plerions, up to their complete undetectability on the background of classical and gigantic H II regions. A new selection effect, in fact, arises from these factors connected with additional limitations made by the real structure of the interstellar medium on the statistical investigations of SNRs. The influence of this effect on the statistical completeness of objects has been estimated.

Investigation Into The Effectiveness of The JLAB High Pressure Rinse System

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

John Mammosser; Timothy Rothgeb; Tong Wang

2003-05-01

As part of a study to reduce field emission in Superconducting radio frequency cavities, an investigation into the effectiveness of the Jefferson Lab's High Pressure Rinse (HPR) system is underway. This paper describes discoveries from this investigation, the procedural changes made during this investigation, current vertical test results and further plans for improvements and monitoring.

Investigation of installation effects of single-engine convergent-divergent nozzles

NASA Technical Reports Server (NTRS)

Burley, J. R., II; Berrier, B. L.

1982-01-01

An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine installation effects on single-engine convergent-divergent nozzles applicable to reduced-power supersonic cruise aircraft. Tests were conducted at Mach numbers from 0.50 to 1.20, at angles of attack from -3 degrees to 9 degrees, and at nozzle pressure ratios from 1.0 (jet off) to 8.0. The effects of empennage arrangement, nozzle length, a cusp fairing, and afterbody closure on total aft-end drag coefficient and component drag coefficients were investigated. Basic lift- and drag-coefficient data and external static-pressure distributions on the nozzle and afterbody are presented and discussed.

"Investigation of Trends in Aerosol Direct Radiative Effects ...

EPA Pesticide Factsheets

While aerosol radiative effects have been recognized as some of the largest sources of uncertainty among the forcers of climate change, there has been little effort devoted to verification of the spatial and temporal variability of the magnitude and directionality of aerosol radiative forcing. A comprehensive investigation of the processes regulating aerosol distributions, their optical properties, and their radiative effects and verification of their simulated effects for past conditions relative to measurements is needed in order to build confidence in the estimates of the projected impacts arising from changes in both anthropogenic forcing and climate change. This study aims at addressing this issue through a systematic investigation of changes in anthropogenic emissions of SO2 and NOx over the past two decades in the United States, their impacts on anthropogenic aerosol loading in the North American troposphere, and subsequent impacts on regional radiation budgets. During the period 1990-2010, SO2 and NOx emissions across the US have reduced by about 66% and 50%, respectively, mainly due to Title IV of the U.S. Clean Air Act Amendments (CAA). A methodology is developed to consistently estimate emission inventories for the 20-year period accounting for air quality regulations as well as population trends, economic conditions, and technology changes in motor vehicles and electric power generation. The coupled WRF-CMAQ model is applied for time periods pre a

The role of observational investigations in comparative effectiveness research.

PubMed

Marko, Nicholas F; Weil, Robert J

2010-12-01

Comparative effectiveness research (CER) seeks to inform clinical decisions between alternate treatment strategies using data that reflects real patient populations and real-world clinical scenarios for the purpose of improving patient outcomes. There are multiple clinical situations where the unique characteristics of observational investigations can inform medical decision-making within the CER paradigm. Accordingly, it is critical for clinicians to appreciate the strengths and limitations of observational research, particularly as they apply to CER. This review focuses on the role of observational research in CER. We discuss the concept of evidence hierarchies as they relate to observational research and CER, review the scope and nature of observational research, present the rationale for its inclusion in CER investigations, discuss potential sources of bias in observational investigations as well as strategies used to compensate for these biases, and discuss a framework to implement observational research in CER. The CER paradigm recognizes the limitations of hierarchical models of evidence and favors application of a strength-of-evidence model. In this model, observational research fills gaps in randomized clinical trial data and is particularly valuable to investigate effectiveness, harms, prognosis, and infrequent outcomes as well as in circumstances where randomization is not possible and in studies of many surgical populations. Observational investigations must be designed with careful consideration of potential sources of bias and must incorporate strategies to control such bias prospectively, and their results must be reported in a uniform and transparent fashion. When these conditions can be achieved, observational research represents a valuable and critical component of modern CER. © 2010, International Society for Pharmacoeconomics and Outcomes Research (ISPOR).

Investigation of fabrication and environmental effects on bioceramic bone scaffolds

NASA Astrophysics Data System (ADS)

Vivanco Morales, Juan Francisco

2011-12-01

Bioactive ceramic materials like tricalcium phosphates (TCP) have been emerging as viable material alternatives to the current therapies of bone scaffolding to target fracture healing and osteoporosis. Once scaffolds are implanted at the defect site they should provide mechanical and biological functions, ultimately serving to facilitate with surrounding native tissue. Optimal osteogenic signal expression and subsequent differentiation of cells seeded on the scaffold in both in vivo and in vitro conditions is known to be influenced by scaffold properties and biomechanical environmental conditions. Thus, the objective of this research was to investigate the effect of fabrication and environmental variables on the properties of bioceramic scaffolds for bone tissue engineering applications. Specifically, the effect of sintering temperature in the range of 950°C -1150°C of a cost-effective on a large scale manufacturing process, on the physical and mechanical properties of bioceramic bone scaffolds, was investigated. In addition, the effect of a controlled environment was investigated by implementing a bioreactor and bone loading system to study the response of ex vivo trabecular bone to compressive load while perfused with culture medium. Collectively, this thesis demonstrates that: (1) the sintering temperature to fabricate bioceramic scaffolds can be tuned to structural properties, and (2) the use of a controlled mechanical and biochemical environment can enhance bone tissue development. These findings support the development of clinically successful bioceramic scaffolds that may stimulate bone regeneration and scaffold integration while providing structural integrity.

a Moessbauer Effect and Fenske-Hall Molecular Orbital Study of the Electronic Properties of Organoiron Clusters.

NASA Astrophysics Data System (ADS)

Buhl, Margaret Linn

The electronic properties of trinuclear iron, tetranuclear iron butterfly, iron-cobalt, and iron-copper clusters have been studied experimentally at 78K by the Mossbauer effect and theoretically by Fenske-Hall molecular orbital calculations. The Mossbauer effect isomer shift is very sensitive to the differences in the iron s-electron densities in these clusters and, as expected, decreases as the sum of the iron 4s Mulliken population and the Clementi and Raimondi effective nuclear charge increases. The molecular orbital wave functions and the Mulliken atomic charges are used to calculate the electric field gradient at the metal nuclei and the iron Mossbauer effect quadrupole splittings. The valence contribution was found to be the major component of the electric field gradient in all the clusters studied. In general the calculated value of Delta E_ {Q} is larger than the observed value, as a result of neglect of the valence Sternheimer factor, R. The metal charge depends upon its electronegativity and upon the nature of its Lewis base ligands. The carbonyl ligand carbon charge becomes more positive as the metal electronegativity increases. The oxygen charge becomes more negative as the anionic cluster charge increases, and in so doing, yields the maximum anionic charge separation. The electronic properties of the terminal carbonyl ligands are similar to those of carbon monoxide, whereas the electronic properties of the bridging carbonyl ligands are similar to those of the carbonyl group found in aldehydes and ketones.

Investigation of the Effect of Blade Sweep on Rotor Vibratory Loads

NASA Technical Reports Server (NTRS)

Tarzanin, F. J., Jr.; Vlaminck, R. R.

1983-01-01

The effect of helicopter rotor blade planform sweep on rotor vibratory hub, blade, and control system loads has been analytically investigated. The importance of sweep angle, sweep initiation radius, flap bending stiffness and torsion bending stiffness is discussed. The mechanism by which sweep influences the vibratory hub loads is investigated.

Effects of aleurone layer on rice cooking: A histological investigation.

PubMed

Wu, Jianyong; Chen, Jun; Liu, Wei; Liu, Chengmei; Zhong, Yejun; Luo, Dawen; Li, Zhongqiang; Guo, Xiaojuan

2016-01-15

Understanding how aleurone layer (AL) affects rice cooking behaviour is important for rice processing. Individual effects of AL on rice cooking behaviour were evaluated and histological characters of AL before and after cooking were investigated. AL slightly affected rice cooking quality (optimum cooking time, water absorption, volume expansion ratio and total solids loss) while remarkably affected rice texture (hardness and adhesiveness) and peak viscosity. Histological investigation showed that channels were formed in AL during cooking. The channels facilitated the penetration of water, which could explain why AL exhibited slight effects on rice cooking quality. In addition, thick cell walls and thermally stable aleurone grains were widely distributed in AL. Leached components accumulated on them and formed a reinforced coated film on rice surface during cooking, which may be a possible mechanism accounting for the remarkable effect of AL on rice texture. Histological characters of AL are closely related with rice cooking behaviour. Copyright © 2014 Elsevier Ltd. All rights reserved.

Investigation of the Hepatotoxic and Immunotoxic Effects of the Peroxisome Proliferator Perfluorodecanoic Acid

DTIC Science & Technology

1991-04-30

np. A #127 6Investigation of the Hepatotoxic and OHIO Immunotoxic Effects of the Peroxisome AJE Proliferator Perfluorodecanoic Acid Donald E. Frazier...Investigation of the Hepatotoxic and Immunotoxic Effects G-AFOSR 90-0371 of the Peroxisome Proliferator Perfluorodecanoic Acid TA - 2312/A5 L AUTMOS) Donald E...involved evaluation of the immunotoxic and toxic effects of perfluorodecanoic acid (PFDA). Eight day exposure to PFDA caused thymic atrophy with marked

24/7 Operational Effectiveness Toolset: Mishap Investigation Interface

DTIC Science & Technology

2008-10-01

analysis software product. The toolset was based upon the Sleep, Activity, Fatigue, and Task Effectiveness (SAFTE™; Hursh et al., 2004). The SAFTE...meeting was for the purpose of requirements analysis , in which the designers elicited task information from the SMEs. The second meeting included a...investigators who also served as our SMEs. The requirements analysis revealed how fatigue related information is entered into the report of an Air Force

Investigating the Effects of Authentic Childhood Games in Teaching English

ERIC Educational Resources Information Center

Hursen, Cigdem; Salaz, Dursun

2016-01-01

The purpose of this study is to investigate the effects of authentic childhood games in teaching English. The study group of the research consists of 43 5-year-old kindergarten students. The study was carried out in the first semester of 2014-2015 academic year. An experimental method was used in this study to state the effects of teaching English…

Investigating the Effects of Planning on L2 Text Chat Performance

ERIC Educational Resources Information Center

Hsu, Hsiu-Chen

2012-01-01

Over the last decade, a small body of SLA research has examined the effects of task planning on L2 production. This research has revealed positive results concerning the effect of pre-task and online planning on oral and written production. However, no studies to date have investigated the joint effects of pre-task and online planning. In…

Investigation of multiple scattering effects in aerosols

NASA Technical Reports Server (NTRS)

Deepak, A.

1980-01-01

The results are presented of investigations on the various aspects of multiple scattering effects on visible and infrared laser beams transversing dense fog oil aerosols contained in a chamber (4' x 4' x 9'). The report briefly describes: (1) the experimental details and measurements; (2) analytical representation of the aerosol size distribution data by two analytical models (the regularized power law distribution and the inverse modified gamma distribution); (3) retrieval of aerosol size distributions from multispectral optical depth measurements by two methods (the two and three parameter fast table search methods and the nonlinear least squares method); (4) modeling of the effects of aerosol microphysical (coagulation and evaporation) and dynamical processes (gravitational settling) on the temporal behavior of aerosol size distribution, and hence on the extinction of four laser beams with wavelengths 0.44, 0.6328, 1.15, and 3.39 micrometers; and (5) the exact and approximate formulations for four methods for computing the effects of multiple scattering on the transmittance of laser beams in dense aerosols, all of which are based on the solution of the radiative transfer equation under the small angle approximation.

Investigation of multiple scattering effects in aerosols

NASA Astrophysics Data System (ADS)

Deepak, A.

1980-05-01

The results are presented of investigations on the various aspects of multiple scattering effects on visible and infrared laser beams transversing dense fog oil aerosols contained in a chamber (4' x 4' x 9'). The report briefly describes: (1) the experimental details and measurements; (2) analytical representation of the aerosol size distribution data by two analytical models (the regularized power law distribution and the inverse modified gamma distribution); (3) retrieval of aerosol size distributions from multispectral optical depth measurements by two methods (the two and three parameter fast table search methods and the nonlinear least squares method); (4) modeling of the effects of aerosol microphysical (coagulation and evaporation) and dynamical processes (gravitational settling) on the temporal behavior of aerosol size distribution, and hence on the extinction of four laser beams with wavelengths 0.44, 0.6328, 1.15, and 3.39 micrometers; and (5) the exact and approximate formulations for four methods for computing the effects of multiple scattering on the transmittance of laser beams in dense aerosols, all of which are based on the solution of the radiative transfer equation under the small angle approximation.

Effect of substitutions and defects in half-Heusler FeVSb studied by electron transport measurements and KKR-CPA electronic structure calculations

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

Jodin, L.; Tobola, J.; Pecheur, P.

2004-11-01

The structural and electron transport properties of the pure and Co-, Ti-, and Zr-substituted FeVSb half-Heusler phases have been investigated using x-ray diffraction, Moessbauer spectroscopy, and Electron Probe Microscopy Analysis as well as resistivity, thermopower, and Hall effect measurements in the 80-900 K temperature range. In a parallel study, the electronic structures of FeVSb and the aforementioned alloys were calculated using the Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA) in the LDA framework. The electronic densities of states and dispersion curves were obtained. The crystal structure stability and site preference analysis were addressed using total energy computations. Most ofmore » these experimental results correspond to electronic structure computations only if they take into account extra crystal defects such as antisite defects or vacancies present to various extents in the samples. Indeed a remarkable variation of KKR-CPA density of states occurring both in FeVSb and FeV{sub 1-x}Zr{sub x}Sb including defects may explain why FeVSb is not fully semiconducting as well as why there is a change of the thermopower sign in the FeV{sub 1-x}Zr{sub x}Sb versus x content.« less

Investigating the Effectiveness of Computer Simulations for Chemistry Learning

ERIC Educational Resources Information Center

Plass, Jan L.; Milne, Catherine; Homer, Bruce D.; Schwartz, Ruth N.; Hayward, Elizabeth O.; Jordan, Trace; Verkuilen, Jay; Ng, Florrie; Wang, Yan; Barrientos, Juan

2012-01-01

Are well-designed computer simulations an effective tool to support student understanding of complex concepts in chemistry when integrated into high school science classrooms? We investigated scaling up the use of a sequence of simulations of kinetic molecular theory and associated topics of diffusion, gas laws, and phase change, which we designed…

Comparative Investigation of Protective Effects of Metyrosine and Metoprolol Against Ketamine Cardiotoxicity in Rats.

PubMed

Ahiskalioglu, Ali; Ince, Ilker; Aksoy, Mehmet; Ahiskalioglu, Elif Oral; Comez, Mehmet; Dostbil, Aysenur; Celik, Mine; Alp, Hamit Hakan; Coskun, Resit; Taghizadehghalehjoughi, Ali; Suleyman, Bahadir

2015-10-01

This study investigated the effect of metyrosine against ketamine-induced cardiotoxicity in rats and compared the results with the effect of metoprolol. In this study, rats were divided into groups A, B and C. In group A, we investigated the effects of a single dose of metyrosine (150 mg/kg) and metoprolol (20 mg/kg) on single dose ketamine (60 mg/kg)-induced cardiotoxicity. In group B, we investigated the effect of metyrosine and metoprolol, which were given together with ketamine for 30 days. In group C, we investigated the effect of metyrosine and metoprolol given 15 days before ketamine and 30 days together with ketamine on ketamine cardiotoxicity. By the end of this process, we evaluated the effects of the levels of oxidant-antioxidant parameters such as MDA, MPO, 8-OHGua, tGSH, and SOD in addition to CK-MB and TP I on cardiotoxicity in rat heart tissue. The experimental results show that metyrosine prevented ketamine cardiotoxicity in groups A, B and C and metoprolol prevented it in only group C.

Experimental Investigation of Effectiveness of Magnetic Field on Food Freezing Process

NASA Astrophysics Data System (ADS)

Suzuki, Toru; Takeuchi, Yuri; Masuda, Kazunori; Watanabe, Manabu; Shirakashi, Ryo; Fukuda, Yutaka; Tsuruta, Takaharu; Yamamoto, Kazutaka; Koga, Nobumitsu; Hiruma, Naoya; Ichioka, Jun; Takai, Kiyoshi

Recently, several food refrigeration equipments that utilize magnetic field have attracted much attention from food production companies, consumers and mass media. However, the effectiveness of the freezers is not scientifically examined. Therefore, the effectiveness should be clarified by experiments or theoretical considerations. In this study, the effect of weak magnetic field (about 0.0005 T) on freezing process of several kinds of foods was investigated by using a specially designed freezer facilitated with magnetic field generator. The investigation included the comparison of freezing curves, drip amount, physicochemical evaluations on color and texture, observation of microstructure, and sensory evaluation. From the results of the control experiments, it can be concluded that weak magnetic field around 0.0005 T provided no significant difference on temperature history during freezing and on the qualities of frozen foods, within our experimental conditions.

Investigating investigators: how presentation order influences participant-investigators' interpretations of eyewitness identification and alibi evidence.

PubMed

Dahl, Leora C; Brimacombe, C A Elizabeth; Lindsay, D Stephen

2009-10-01

Presentation order of ID and Alibi evidence was manipulated for undergraduate participants who conducted a simulated police investigation. Experiment 1 found a recency effect when an eyewitness rejected the investigator's suspect. Experiment 2 also examined order effects, exploring how participant-investigators evaluated alibi information in addition to eyewitness ID information. When investigators saw the witness identify the suspect but also received a strong alibi for that suspect a recency effect occurred, such that whichever piece of information occurred at the end of the procedure had the strongest impact on investigators. Thus, type of evidence and evidence order both had a dramatic influence on participant-investigators' decisions.

Investigation of Compressibility Effect for Aeropropulsive Shear Flows

NASA Technical Reports Server (NTRS)

Balasubramanyam, M. S.; Chen, C. P.

2005-01-01

Rocket Based Combined Cycle (RBCC) engines operate within a wide range of Mach numbers and altitudes. Fundamental fluid dynamic mechanisms involve complex choking, mass entrainment, stream mixing and wall interactions. The Propulsion Research Center at the University of Alabama in Huntsville is involved in an on- going experimental and numerical modeling study of non-axisymmetric ejector-based combined cycle propulsion systems. This paper attempts to address the modeling issues related to mixing, shear layer/wall interaction in a supersonic Strutjet/ejector flow field. Reynolds Averaged Navier-Stokes (RANS) solutions incorporating turbulence models are sought and compared to experimental measurements to characterize detailed flow dynamics. The effect of compressibility on fluids mixing and wall interactions were investigated using an existing CFD methodology. The compressibility correction to conventional incompressible two- equation models is found to be necessary for the supersonic mixing aspect of the ejector flows based on 2-D simulation results. 3-D strut-base flows involving flow separations were also investigated.

Investigation on the structural effect of lignin during the hydrogenolysis process.

PubMed

Shu, Riyang; Long, Jinxing; Xu, Ying; Ma, Longlong; Zhang, Qi; Wang, Tiejun; Wang, Chenguang; Yuan, Zhengqiu; Wu, Qingyun

2016-01-01

Structure has a significant effect on the lignin degradation, so the investigation of structural effect on the lignin depolymerization is important and imperative. In this study, hydrogenolysis of three typical lignins with different structures, dealkaline lignin, sodium lignosulfonate and organosolv lignin, was intensively compared over the synergistic catalyst of CrCl3 and Pd/C. The effects of reaction temperature, time, hydrogen pressure and catalyst dosage on the catalytic performance of lignin species were investigated. The structure evolution of lignins during the hydrogenolysis process was also compared. The results showed that organosolv lignin was more sensitive for hydrogenolysis than others due to its high unsaturation degree and low molecular weight. Further analysis indicated that the hydrogenolysis, hydrodeoxygenation and repolymerization reactions took place and competed intensely. Wherein, the depolymerization products with unsaturated carbonyl groups were prone to repolymerize. And the methylation was helpful to stabilize the depolymerization products and suppress the further repolymerization. Copyright © 2015 Elsevier Ltd. All rights reserved.

Investigating the effect of chemical stress and resource ...

EPA Pesticide Factsheets

Modeling exposure and recovery of fish and wildlife populations after stressor mitigation serves as a basis for evaluating population status and remediation success. The Atlantic killifish (Fundulus heteroclitus) is an important and well-studied model organism for understanding the effects of pollutants and other stressors in estuarine and marine ecosystems. Herein, we develop a density dependent matrix population model for Atlantic killifish that analyzes both size-structure and age class-structure of the population so that we could readily incorporate output from a dynamic energy budget (DEB) model currently under development. This population modeling approach emphasizes application in conjunction with field monitoring efforts (e.g., through effects-based monitoring programs) and/or laboratory analysis to link effects due to chemical stress to adverse outcomes in whole organisms and populations. We applied the model using data for killifish exposed to dioxin-like compounds, taken from a previously published study. Specifically, the model was used to investigate population trajectories for Atlantic killifish with dietary exposures to 112, 296, and 875 pg/g of dioxin with effects on fertility and survival rates. All effects were expressed relative to control fish. Further, the population model was employed to examine age and size distributions of a population exposed to resource limitation in addition to chemical stress. For each dietary exposure concentration o

Synthesis and Properties of Ortho-Nitro-Fe Complex

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

Mishra, A.; Mishra, Niyati; Sharma, R.

2011-07-15

Ortho-Nitro-Fe complex (Transition metal complex) has synthesized by chemical route method and properties of made complex has characterized by X-Ray diffraction (XRD), Moessbauer spectroscopy, Fourier transformation infra-red spectroscopy (FTIR) and X-Ray photoelectron spectroscopy (XPS). XRD analysis shows that sample is crystalline in nature and having particle size in the range of few nano meters. Moessbauer spectroscopy at room temperature shows the oxidation state of Iron (central metal ion) after complaxasion. FTIR spectra of the complex confirms the coordination of metal ion with ligand.

Second Language Comprehensibility Revisited: Investigating the Effects of Learner Background

ERIC Educational Resources Information Center

Crowther, Dustin; Trofimovich, Pavel; Saito, Kazuya; Isaacs, Talia

2015-01-01

The current study investigated first language (L1) effects on listener judgment of comprehensibility and accentedness in second language (L2) speech. The participants were 45 university-level adult speakers of English from three L1 backgrounds (Chinese, Hindi, Farsi), performing a picture narrative task. Ten native English listeners used…

Evolution of the Active Phase of CoMo/Al2O3 Catalysts under Industrial Conditions: a High-Pressure MES Study

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

Dugulan, A.I.; Overweg, A.R.; Craje, M.W.J.

2005-04-26

The behavior of CoMo/Al2O3 catalysts sulfided in H2S/H2 gas mixture, under industrial conditions, was investigated using Moessbauer emission spectroscopy (MES). An intermediate Co-Mo phase is formed after increasing the sulfidation pressure to 4 MPa, favoring the Co-Mo-S phase formation. An increase in the quadrupole splitting value of the Co-sulfide species after treatment at 573 K is proposed as a prerequisite for the formation of ideal Co-Mo-S structures.

Ripples in The Soil

NASA Technical Reports Server (NTRS)

2004-01-01

This is a three-dimensional stereo anaglyph of an image taken by the front navigation camera onboard the Mars Exploration Rover Spirit, showing an interesting patch of rippled soil. Spirit took this image on sol 37 (Feb. 9, 2004) after completing the longest drive ever made by a rover on another planet - 21.2 meters (69.6 feet). On sol 38 scientists plan to investigate this interesting location with the microscopic imager and Moessbauer spectrometer on Spirit's instrument deployment device.

Investigating the Effect of Argument-Driven Inquiry in Laboratory Instruction

ERIC Educational Resources Information Center

Demircioglu, Tuba; Ucar, Sedat

2015-01-01

The aim of this study is to investigate the effect of argument-driven inquiry (ADI) based laboratory instruction on the academic achievement, argumentativeness, science process skills, and argumentation levels of pre-service science teachers in the General Physics Laboratory III class. The study was conducted with 79 pre-service science teachers.…

Investigation of Systematic Effects in Atmospheric Microthermal Probe Data.

DTIC Science & Technology

1992-12-01

MICROTHERMAL PROBE DATA by Daniel S. Roper December, 1992 Thesis Advisor. Donald L. Walters Approved for public release; distribution is unlimited 93...EFFWS IN ATMOSP RIC MICROTHERMAL PROBE DATA 12. PERSONALAUTHOR(S) Da s. Roper 13s. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (year, moith, day...distribution is unlimited. Investigation of Systematic Effects in Atmospheric Microthermal Probe Data by Daniel S. Roper Captain, United States Army B.S

Effective use of forensic science in volume crime investigations: identifying recurring themes in the literature.

PubMed

Ludwig, Anika; Fraser, Jim

2014-01-01

New scientific, technological and legal developments, particularly the introduction of national databases for DNA and fingerprints, have led to increased use of forensic science in the investigation of crime. There is an assumption, and in some instances specific assertions, that such developments bring improvements either in broad criminal justice terms or more narrowly in terms of economic or practical efficiencies. The underlying presumption is that the new technological opportunities will be understood and effectively implemented. This research investigates whether such increases in activity have also been accompanied by improvements in the effective use of forensic science. A systematic review of thirty-six reports published (predominantly in England and Wales) since the 1980s, which have considered the use of forensic science in the investigation of volume crimes, was carried out. These reports have identified a number of recurrent themes that influenced how effectively forensic science was used in investigations. The themes identified included forensic knowledge and training of investigators, communication and information exchange between specialists and investigators, timeliness of forensic results, interagency relationships and deployment of crime scene examiner resources. The research findings suggest that these factors continue to hinder the effective use of forensic science despite technological advances and this paper considers their potential causes. © 2013.

Investigation of the effects of short chain processing additives on polymers

NASA Technical Reports Server (NTRS)

Singh, J. J.; Stclair, T. L.; Pratt, J. R.

1986-01-01

The effects of low level concentrations of several short chain processing additives on the properties of the 4,4'-bis(3,4-dicarboxyphenoxy) diphenylsulfide dianhydride (BDSDA)/4,4'-diaminodiphenyl ether (ODA)/1,3'-diaminobenzene (m-phenylene diamine) (MPA) (422) copolyimide were investigated. It was noted that 5 percent MPD/phthalic anhydride (PA) is more effective than 5 percent ODA/PA and BDSDA/aniline (AN) in strengthening the host material. However, the introduction of 10 percent BDSDA/AN produces disproportionately high effects on free volume and free electron density in the host copolyimide.

The Microscopic Magnetic Properties of W-type Hexaferrite Powder Prepared by A Sol-Gel Route

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

Jotania, Rajshree; Chauhan, Chetna; Sharma, Pooja

2010-12-01

Magnetic particles of W-type barium-calcium hexaferrite (BaCa{sub 2}Fe{sub 16}O{sub 27}) have been synthesized using a Stearic acid gel route. The gel precursors were dried at 100 deg. C for 2 hrs and then calcinated at 650 deg. C, 750 deg. C, 850 deg. C and 950 deg. C for 4 hrs in a furnace and slowly cooled to room temperature in order to obtain barium-calcium hexaferrite particles. The microscopic magnetic properties of prepared samples studying using Moessbauer spectroscopy. Moessbauer spectra of all samples were recorded at room temperature. Mossbauer parameters like Isomer shift, Quadruple splitting etc. were calculated with respectmore » to iron foil. Barium calcium hexaferrite samples heated at 650 deg. C, 750 deg. C, 850 deg. C show relaxation type Moessbauer spectra along with paramagnetic doublet. The intensity of paramagnetic doublet increases with temperature confirm the presence of ferrous ions in the samples, where as sample calcinated at 950 deg. C confirm the presence of ferrimagnetic phase with partial super paramagnetic nature of prepared hexaferrite sample.« less

Investigation of Effective Material Properties of Stony Meteorites

NASA Technical Reports Server (NTRS)

Agrawal, Parul; Carlozzi, Alex; Bryson, Kathryn

2016-01-01

To assess the threat posed by an asteroid entering Earth's atmosphere, one must predict if, when, and how it fragments during entry. A comprehensive understanding of the Asteroid material properties is needed to achieve this objective. At present, the meteorite material found on Earth are the only objects from an entering asteroid that can be used as representative material and be tested inside a laboratory setting. Therefore, unit cell models are developed to determine the effective material properties of stony meteorites and in turn deduce the properties of asteroids. The unit cell is representative volume that accounts for diverse minerals, porosity, and matrix composition inside a meteorite. The various classes under investigation includes H-class, L-class, and LL-class chondrites. The effective mechanical properties such as Young's Modulus and Poisson's Ratio of the unit cell are calculated by performing several hundreds of Monte-Carlo simulations. Terrestrial analogs such as Basalt and Gabbro are being used to validate the unit cell methodology.

The homicidol effect: investigating murder as a fitness signal.

PubMed

Dahlén, Micael; Söderlund, Magnus

2012-01-01

This article extends homicide adaptation theory by investigating signal effects of a murder. In two experiments (N = 299 and N = 161) participants reported their perceptions of a described person. The first study manipulated the information about the person (including or excluding a single sentence stating that the person has committed a murder) and stimulus person/observer sex match (same vs. opposite sex). Results suggest that murder functions as a signal of the described person's fitness that enhances observers' evaluations and inclination to interact with the person. Opposite-sex observers evaluate the murderer's intent more favorably than same-sex observers, but these evaluations of intent produce differential (positive vs. negative) effects between the two groups. The second study replicated the findings and ruled out potential confounds.

Group Investigation Effects on Achievement, Motivation, and Perceptions of Students in Singapore

ERIC Educational Resources Information Center

Tan, Ivy Geok Chin; Sharan, Shlomo; Lee, Christine Kim Eng

2007-01-01

In an experiment conducted in 7 eighth-grade (Ages 13-14) classes in Singapore, the authors evaluated the effects of the group investigation method of cooperative learning versus the effects of the traditional whole-class method of instruction on students' academic achievement and on their motivation to learn. The authors also investigated…

The Effect of Multipart Prompts on Children's Testimonies in Sexual Abuse Investigations

ERIC Educational Resources Information Center

Katz, Carmit; Hershkowitz, Irit

2012-01-01

Objective: The current study aimed to explore the frequency and effects of multipart prompts on the testimonies of children who were alleged victims of sexual abuse and were interviewed using the National Institute of Child Health and Human Development (NICHD) Investigative Protocol. The effects of the multipart prompts were studied by considering…

Investigation of thermal effects on FinFETs in the quasi-ballistic regime

NASA Astrophysics Data System (ADS)

Yin, Longxiang; Shen, Lei; Di, Shaoyan; Du, Gang; Liu, Xiaoyan

2018-04-01

In this work, the thermal effects of FinFETs in the quasi-ballistic regime are investigated using the Monte Carlo method. Bulk Si nFinFETs with the same fin structure and two different gate lengths L g = 20 and 80 nm are investigated and compared to evaluate the thermal effects on the performance of FinFETs in the quasi-ballistic regime. The on current of the 20 nm FinFET with V gs = 0.7 V does not decrease with increasing lattice temperature (T L) at a high V ds. The electrostatic properties in the 20 nm FinFET are more affected by T L than those in the 80 nm FinFET. However, the electron transport in the 20 nm FinFET is less affected by T L than that in the 80 nm FinFET. The electrostatic properties being more sensitive and the electron transport being less sensitive to thermal effects in the quasi-ballistic regime than in the diffusive regime should be considered for effective device modeling and design.

An investigation of the spatial selectivity of the duration after-effect.

PubMed

Maarseveen, Jim; Hogendoorn, Hinze; Verstraten, Frans A J; Paffen, Chris L E

2017-01-01

Adaptation to the duration of a visual stimulus causes the perceived duration of a subsequently presented stimulus with a slightly different duration to be skewed away from the adapted duration. This pattern of repulsion following adaptation is similar to that observed for other visual properties, such as orientation, and is considered evidence for the involvement of duration-selective mechanisms in duration encoding. Here, we investigated whether the encoding of duration - by duration-selective mechanisms - occurs early on in the visual processing hierarchy. To this end, we investigated the spatial specificity of the duration after-effect in two experiments. We measured the duration after-effect at adapter-test distances ranging between 0 and 15° of visual angle and for within- and between-hemifield presentations. We replicated the duration after-effect: the test stimulus was perceived to have a longer duration following adaptation to a shorter duration, and a shorter duration following adaptation to a longer duration. Importantly, this duration after-effect occurred at all measured distances, with no evidence for a decrease in the magnitude of the after-effect at larger distances or across hemifields. This shows that adaptation to duration does not result from adaptation occurring early on in the visual processing hierarchy. Instead, it seems likely that duration information is a high-level stimulus property that is encoded later on in the visual processing hierarchy. Copyright © 2016 Elsevier Ltd. All rights reserved.

A second international cooperative investigation into thioacetazone side effects

PubMed Central

Miller, A. B.; Nunn, A. J.; Robinson, D. K.; Fox, Wallace; Somasundaram, P. R.; Tall, Ruth

1972-01-01

As part of a large-scale international cooperative investigation into the side effects of thioacetazone-containing regimens in the treatment of tuberculosis, an evaluation has been made of the variation in the frequency of side effects between different countries and between different centres in the same country and of the likely reasons for this variation. In 3 countries patients of different racial origin were under observation in the same hospital. Over a 12-week period of treatment there was considerable variation between the countries and centres in the overall frequency of side effects and of those leading to a major departure from prescribed treatment, the variation being similar for the two thioacetazone-containing regimens and for the streptomycin plus isoniazid control regimen, though at a lower level for the latter. In Malaysia, Singapore, and Trinidad, where different racial groups were under treatment, there was no clear indication that race was an important factor in explaining the differences between countries, except for cutaneous side effects in Trinidad and possibly in Malaysia. It is concluded that the differences in the frequency of side effects to thioacetazone-containing regimens probably result from variation in the closeness of supervision of patients, in the recording and interpretation of side effects, and in environmental factors including the previous use of other medicaments or exposure to sensitizing substances. PMID:4118761

Effect of Temperature on Acoustic Evaluation of Standing trees and logs: Part 1-Laboratory investigation

Treesearch

Shan Gao; Xiping Wang; Lihai Wang; R. Bruce. Allison

2012-01-01

The goals of this study were to investigate the effect of environment temperature on acoustic velocity of standing trees and green logs and to develop workable models for compensating temperature differences as acoustic measurements are performed in different climates and seasons. The objective of Part 1 was to investigate interactive effects of temperature and...

Moessbauer Mineralogy of Rock, Soil, and Dust at Gusev Crater, Mars: Spirit's Journey through Weakly Altered Olivine Basalt on the Plains and Pervasively Altered Basalt in the Columbia Hills

NASA Technical Reports Server (NTRS)

Morris, R. V.; Klingelhoefer, G.; Schroeder, C.; Rodionov, D. S.; Yen, A.; Ming, D. W.; deSouza, P. A., Jr.; Fleischer, I.; Wdowiak, T.; Gellert, R.;

Sulfidation of Co/Al[sub 2]O[sub 3] and CoMo/Al[sub 2]O[sub 3] catalysts studied by Moessbauer emission spectroscopy

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

Craje, M.W.J.; Kraan, A.M. van der; Beer, V.H.J. de

1993-10-01

The structure of hydrodesulfurization catalysts is relevant to many industries. The sulfidation of uncalcined and calcined alumina-supported cobalt and cobalt-molybdenum catalysts was systematically studied by means of in situ Moessbauer emission spectroscopy (MES) at room temperature. The spectra obtained during the stepwise sulfidation of the uncalcined catalysts clearly resemble those observed for carbon-supported ones. Hence, the interpretation of the spectra of the alumina-supported catalysts is based on the conclusions drawn from the MES studies of the carbon-supported catalysts, which are less complex because Co ions do not diffuse into the support. It is demonstrated that not only in sulfided CoMo/Al[submore » 2]O[sub 3], but also in sulfided Co/Al[sub 2]O[sub 3], catalysts Co-sulfide species with a [open quotes]Co-Mo-S[close quotes]-type quadrupole splitting can be formed. It is concluded that the Co-sulfide species formed in sulfided Co/Al[sub 2]O[sub 3] and CoMo/Al[sub 2]O[sub 3] catalysts are essentially the same, only the particle size and ordering of the Co-sulfide species may differ, as in the case of Co/C and CoMo/C catalysts. The function of the Mo, which is present as MoS[sub 2], is merely to stabilize very small Co-sulfide particles, which in the limit contain only one single Co atom. Furthermore, it turns out that the value of the electric quadrupole splitting (Q.S. value) of the Co-sulfide phase in the sulfided catalysts depends on the sulfiding temperature and Co content. This observation leads to the conclusion that large Q.S. values point to the presence of very small Co-sulfide entities or particles (the lower limit being [open quotes]particles[close quotes] containing only one Co atom, such as proposed in the [open quotes]Co-Mo-S[close quotes] model), whereas small Q.S. values point to the presence of large Co-sulfide particles (the upper limit being crystalline Co[sub 9]S[sub 8]). 28 refs., 7 figs., 6 tabs.« less

Investigation of biological effects of some Mannich Bases containing Bis-1,2,4- Triazole.

PubMed

Parlak, A E; Celik, S; Karatepe, M; Turkoglu, S; Alayunt, N O; Dastan, S D; Ulas, M; Sandal, S; Tekin, S; Koparir, M

2016-06-30

In this study, the effects of Mannich bases containing bis-1,2,4-triazole on the levels of in vivo malondialdehyde (MDA) and antioxidant vitamins (A, E, C) were examined in serum, livers and kidneys of rats. DA and vitamin (A, E, C) levels were determined by high performance liquid chromatography (HPLC). Antioxidant effect was investigated by determining the MDA levels in Saccharomyces cerevisiae cells as in vitro. Furthermore, the antitumor effects of compounds were investigated against MCF-7 human breast cancer cells. Interrelations of results among control and compound groups were evaluated using SPSS statistical software package. As a result, some of the compounds showed effective biological activity when compared to control conditions. The test compounds used in this study may be effective for utilization in the selection and design of model compounds for further studies.

Experimental Investigation of a Wing-in-Ground Effect Craft

PubMed Central

Tofa, M. Mobassher; Ahmed, Yasser M.; Jamei, Saeed; Priyanto, Agoes; Rahimuddin

2014-01-01

The aerodynamic characteristics of the wing-in-ground effect (WIG) craft model that has a noble configuration of a compound wing was experimentally investigated and Universiti Teknologi Malaysia (UTM) wind tunnel with and without endplates. Lift and drag forces, pitching moment coefficients, and the centre of pressure were measured with respect to the ground clearance and the wing angle of attack. The ground effect and the existence of the endplates increase the wing lift-to-drag ratio at low ground clearance. The results of this research work show new proposed design of the WIG craft with compound wing and endplates, which can clearly increase the aerodynamic efficiency without compromising the longitudinal stability. The use of WIG craft is representing an ambitious technology that will help in reducing time, effort, and money of the conventional marine transportation in the future. PMID:24701170

Experimental investigation of a wing-in-ground effect craft.

PubMed

Tofa, M Mobassher; Maimun, Adi; Ahmed, Yasser M; Jamei, Saeed; Priyanto, Agoes; Rahimuddin

2014-01-01

The aerodynamic characteristics of the wing-in-ground effect (WIG) craft model that has a noble configuration of a compound wing was experimentally investigated and Universiti Teknologi Malaysia (UTM) wind tunnel with and without endplates. Lift and drag forces, pitching moment coefficients, and the centre of pressure were measured with respect to the ground clearance and the wing angle of attack. The ground effect and the existence of the endplates increase the wing lift-to-drag ratio at low ground clearance. The results of this research work show new proposed design of the WIG craft with compound wing and endplates, which can clearly increase the aerodynamic efficiency without compromising the longitudinal stability. The use of WIG craft is representing an ambitious technology that will help in reducing time, effort, and money of the conventional marine transportation in the future.

Size-dependent effects in supported highly dispersed Fe2O3 catalysts, doped with Pt and Pd

NASA Astrophysics Data System (ADS)

Cherkezova-Zheleva, Zara; Shopska, Maya; Mitov, Ivan; Kadinov, Georgi

2010-06-01

Series of Fe and Fe-Me (Me = Pt or Pd) catalyst supported on γ-Al2O3, TiO2 (anatase) or diatomite were prepared by the incipient wetness impregnation method. The metal loading was 8 wt.% Fe and 0.7 wt.% noble metal. The preparation and pretreatment conditions of all studied samples were kept to be the same. X-ray diffraction, Moessbauer spectroscopy, X-ray photoelectron spectroscopy and temperature-programmed reduction are used for characterization of the supports and the samples at different steps during their treatment and catalytic tests. The catalytic activity of the samples was tested in the reaction of total benzene oxidation. The physicochemical and catalytic properties of the obtained materials are compared with respect of the different chemical composition, dispersion of used carriers and of the supported phases. Samples with the same composition prepared by mechanical mixing are studied as catalysts for comparison and for clearing up the presence of size-dependent effect, also.

Investigating the Modality and Redundancy Effects for Learners with Persistent Pain

ERIC Educational Resources Information Center

Smith, Alexander; Ayres, Paul

2016-01-01

Two experiments were conducted to investigate how individuals with persistent pain would respond to instructional materials designed to promote the modality and redundancy effects. It was predicted that persistent pain would reduce the positive impact of narrated text due to reduced working memory capacity. One hundred thirty-seven full-time…

A Sociocultural Investigation of the Effects of Peer Interaction on Play

ERIC Educational Resources Information Center

Sluss, Dorothy J.; Stremmel, Andrew J.

2004-01-01

This study examined Vygotsky's theoretical notion that play creates the zone of proximal development by investigating the effects of peer interaction within the context of constructive play with blocks. The authors used the Play Observation Scale (Rubin, 1989) to observe 100 four-year-olds in naturalistic settings. Forty-eight children were…

An Investigation of the Effectiveness of Concept Mapping on Turkish Students' Academic Success

ERIC Educational Resources Information Center

Erdogan, Yavuz

2016-01-01

This paper investigates the experimental studies which test the effectiveness of the concept mapping instructional strategy compared to the traditional teaching method. Meta-analysis was used to calculate the effect size of the concept mapping strategy on academic success. Therefore, the analysis includes experimental studies conducted in Turkey…

Ditching Investigations of Dynamic Models and Effects of Design Parameters on Ditching Characteristics

NASA Technical Reports Server (NTRS)

Fisher, Lloyd J; Hoffman, Edward L

1958-01-01

Data from ditching investigations conducted at the Langley Aeronautical Laboratory with dynamic scale models of various airplanes are presented in the form of tables. The effects of design parameters on the ditching characteristics of airplanes, based on scale-model investigations and on reports of full-scale ditchings, are discussed. Various ditching aids are also discussed as a means of improving ditching behavior.

Investigation of the Phase Stabilizing Effect of Potassium Fluoride on Ammonium Nitrate

DTIC Science & Technology

1989-07-01

fit? FE CP R+bD S&1:,C)4-0i Investigation of the Phase Stabilizing Effect of Potassium Fluoride on Ammonium Nitrate Re-f.-: R& D # 5955-CH-OX...Distribution I Series KF 220988 Humide Amonium Nitrate AvaIldbII~ty Codes Avail arid i or Dist Special 3. DISCUSSION 4. SUMMARY 5. APPENDIX Io. . 1...the participating phases. The system was used to investigate the phase properties of amonium nitrate samples, which were melted with 2 weight % of

Further Investigating Method Effects Associated with Negatively Worded Items on Self-Report Surveys

ERIC Educational Resources Information Center

DiStefano, Christine; Motl, Robert W.

2006-01-01

This article used multitrait-multimethod methodology and covariance modeling for an investigation of the presence and correlates of method effects associated with negatively worded items on the Rosenberg Self-Esteem (RSE) scale (Rosenberg, 1989) using a sample of 757 adults. Results showed that method effects associated with negative item phrasing…

Investigating Factors Related to the Effects of Time-Out on Stuttering in Adults

ERIC Educational Resources Information Center

Franklin, Diane E.; Taylor, Catherine L.; Hennessey, Neville W.; Beilby, Janet M.

2008-01-01

Background: Response-contingent time-out has been shown to be an effective technique for enhancing fluency in people who stutter. However, the factors that determine individual responsiveness to time-out are not well understood. Aims: The study investigated the effectiveness of using response-contingent time-out to reduce stuttering frequency in…

Investigation of the Neutral Gas Pressure Effect on the Metal Resistive Bolometer

NASA Astrophysics Data System (ADS)

Zhang, D.; Giannone, L.; Grulke, O.; Piechotka, M.; Windisch, T.; Stark, A.; Klinger, T.

2008-03-01

The bolometer system planned for W7-X consists mainly of metal (Au) resistive detector arrays. All the detectors are exposed to neutral gas environment. The thin bolometer foil used for detecting the radiated power loss may be sensitive to the neutral gas pressure due to the strain gauge effect. Recently, a prototype of this kind of bolometer camera consisting of 12 channels has been installed on the cylindrical plasma device VINETA in order to investigate the influences of the neutral gas pressure on the bolometer signals. Experiments are carried out for Ar-discharges under different gas pressure conditions. It is found that the pressure effect of the neutral gas can make considerable contributions, thus inducing non-negligible errors of the results in most of the investigated cases. Using the VINETA plasmas (Ar, Te<10 eV, ne<10-19 m-3) as examples, the paper demonstrates and discusses how to minimize the neutral gas effects, especially in the data analysis process. The radiated power and the radiation intensity profile obtained in helicon discharges are presented.

Investigations on Size Effects of Zerodur®

NASA Astrophysics Data System (ADS)

Behar-Lafenetre, S.; Cornillon, L.; Ait-Zaid, S.; Rancurel, M.

2014-06-01

Zerodur® is a well-known glass-ceramic used for optical components because of its unequalled stability under thermal environment (due to its extremely low Coefficient of Thermal Expansion). In particular it has been used since decades in Thales Alenia Space's optical payloads for space telescopes, especially for primary mirrors.The drawback of Zerodur® however is its quite low strength: 10 MPa is historically used as a rule of thumb. However, as performance of space telescopes is increasing, an optimization of the design is necessary and therefore an increase of the strength limit taken into account in the calculations.Thales Alenia Space is therefore currently investigating the so-called "size effect" on Zerodur® (see Weibull theory), under CNES funding, with the aim of re- estimating the lower bound of Zerodur® strength.For this, a complete test campaign has been defined with a high number of samples in order to reduce uncertainties. This article presents the first results obtained.

Speech effort measurement and stuttering: investigating the chorus reading effect.

PubMed

Ingham, Roger J; Warner, Allison; Byrd, Anne; Cotton, John

2006-06-01

The purpose of this study was to investigate chorus reading's (CR's) effect on speech effort during oral reading by adult stuttering speakers and control participants. The effect of a speech effort measurement highlighting strategy was also investigated. Twelve persistent stuttering (PS) adults and 12 normally fluent control participants completed 1-min base rate readings (BR-nonchorus) and CRs within a BR/CR/BR/CR/BR experimental design. Participants self-rated speech effort using a 9-point scale after each reading trial. Stuttering frequency, speech rate, and speech naturalness measures were also obtained. Instructions highlighting speech effort ratings during BR and CR phases were introduced after the first CR. CR improved speech effort ratings for the PS group, but the control group showed a reverse trend. Both groups' effort ratings were not significantly different during CR phases but were significantly poorer than the control group's effort ratings during BR phases. The highlighting strategy did not significantly change effort ratings. The findings show that CR will produce not only stutter-free and natural sounding speech but also reliable reductions in speech effort. However, these reductions do not reach effort levels equivalent to those achieved by normally fluent speakers, thereby conditioning its use as a gold standard of achievable normal fluency by PS speakers.

Numerical investigation of tip clearance effects on the performance of ducted propeller

NASA Astrophysics Data System (ADS)

Ding, Yongle; Song, Baowei; Wang, Peng

2015-09-01

Tip clearance loss is a limitation of the improvement of turbomachine performance. Previous studies show the Tip clearance loss is generated by the leakage flow through the tip clearance, and is roughly linearly proportional to the gap size. This study investigates the tip clearance effects on the performance of ducted propeller. The investigation was carried out by solving the Navier-Stokes equations with the commercial Computational Fluid Dynamic (CFD) code CFX14.5. These simulations were carried out to determine the underlying mechanisms of the tip clearance effects. The calculations were performed at three different chosen advance ratios. Simulation results showed that the tip loss slope was not linearly at high advance due to the reversed pressure at the leading edge. Three type of vortical structures were observed in the tip clearance at different clearance size.

Theoretical investigation of polarization effects in solution: Importance of solvent collective motions

NASA Astrophysics Data System (ADS)

Ishida, Tateki

2015-01-01

Recent theoretical studies on interesting topics related to polarization effects in solutions are presented. As one of interesting topics, ionic liquids (ILs) solvents are focused on. The collective dynamics of electronic polarizability through interionic dynamics and the effect of polarization in ILs, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF6]), are studied with molecular dynamics simulation. Also, the time-dependent polarization effect on the probe betaine dye molecule, pyridinium N-phenoxide, in water is investigated by a time-dependent reference interaction site model self-consistent field (time-dependent RISM-SCF) approach. The importance of considering polarization effects on solution systems related to solvent collective motions is shown.

Theoretical investigation of polarization effects in solution: Importance of solvent collective motions

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

Ishida, Tateki

2015-01-22

Recent theoretical studies on interesting topics related to polarization effects in solutions are presented. As one of interesting topics, ionic liquids (ILs) solvents are focused on. The collective dynamics of electronic polarizability through interionic dynamics and the effect of polarization in ILs, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF{sub 6}]), are studied with molecular dynamics simulation. Also, the time-dependent polarization effect on the probe betaine dye molecule, pyridinium N-phenoxide, in water is investigated by a time-dependent reference interaction site model self-consistent field (time-dependent RISM-SCF) approach. The importance of considering polarization effects on solution systems related to solvent collective motions is shown.

Generalized SAMPLE SIZE Determination Formulas for Investigating Contextual Effects by a Three-Level Random Intercept Model.

PubMed

Usami, Satoshi

2017-03-01

Behavioral and psychological researchers have shown strong interests in investigating contextual effects (i.e., the influences of combinations of individual- and group-level predictors on individual-level outcomes). The present research provides generalized formulas for determining the sample size needed in investigating contextual effects according to the desired level of statistical power as well as width of confidence interval. These formulas are derived within a three-level random intercept model that includes one predictor/contextual variable at each level to simultaneously cover various kinds of contextual effects that researchers can show interest. The relative influences of indices included in the formulas on the standard errors of contextual effects estimates are investigated with the aim of further simplifying sample size determination procedures. In addition, simulation studies are performed to investigate finite sample behavior of calculated statistical power, showing that estimated sample sizes based on derived formulas can be both positively and negatively biased due to complex effects of unreliability of contextual variables, multicollinearity, and violation of assumption regarding the known variances. Thus, it is advisable to compare estimated sample sizes under various specifications of indices and to evaluate its potential bias, as illustrated in the example.

The Flynn Effect in Sibships: Investigating the Role of Age Differences between Siblings

ERIC Educational Resources Information Center

Sundet, Jon Martin; Eriksen, Willy; Borren, Ingrid; Tambs, Kristian

2010-01-01

The aim of the study was to investigate the relationship between the Flynn effect and the effects of age differences between siblings on the intelligence difference between them. In Norway, the secular trends in intelligence-test score means vary both in magnitude and direction. We identified three periods: one period where the mean intelligence…

Inter particle interaction in Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} prepared by self combustion method

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

Sudheesh, V. D.; Vinesh, A.; Lakshmi, N.

Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} has been prepared by self combustion method and studied using X-ray diffraction, Moessbauer spectroscopy and DC magnetization techniques. X-ray diffractogram shows highly crystalline nano sized sample with no impurity phases. The room temperature Moessbauer and magnetization measurements show the co-existence of superparamagnetic and ferrimagnetic particles in the sample. The presence of inter particle interaction is confirmed from the {delta}M(H) curve at 20K. The dependence of magnetic moment below blocking temperature in the field cooling curve indicates that the inter particle interaction is weak in the as prepared sample.

Pervasively Altered Hematite-Rich Deposits Southeast of Home Plate, Gusev Crater, Mars

NASA Technical Reports Server (NTRS)

Schroder, C.; Arvidson, R. E.; Schmidt, M. E.; Gellert, R.; Klingelhoefer, G.; Ming, D. W.; Morris, R. V.; Rice, J. W.; Yen, A. S.; deSouza, P. A., Jr.

2008-01-01

The investigation of Home Plate and its surroundings in the Inner Basin of the Columbia Hills in Gusev Crater has added substantially to the water story on Mars. Textural, morphological, and geochemical evidence from Home Plate point towards an explosive origin, probably a hydrovolcanic explosion [1]. High silica deposits in the immediate vicinity of Home Plate suggest hydrothermal alteration [e.g. 2,3]. Pervasively altered deposits rich in hematite were investigated to the southeast of Home Plate. Of these, the target Halley, the target KingGeorgeIsland on the GrahamLand outcrop, and the targets Montalva and Riquelme on the Troll outcrop were investigated in situ with the Alpha Particle X-ray spectrometer (APXS), the Microscopic Imager (MI), and the Moessbauer (MB) spectrometer (Fig. 1).

Investigation of Seal-to-Floor Effects on Semi-Span Transonic Models

NASA Technical Reports Server (NTRS)

Sleppy, Mark A.; Engel, Eric A.; Watson, Kevin T.; Atler, Douglas M.

2009-01-01

In an effort to achieve the maximum possible Reynolds number (Re) when conducting production testing for flight loads aerodynamic databases, it has been the preferred practice of The Boeing Company / Commercial Airplanes (BCA) -- Loads and Dynamics Group since the early 1990's to test large scale semi-span models in the 11- By 11-Foot Transonic Wind Tunnel (TWT) leg of the Unitary Plan Wind Tunnel (UPWT) at the NASA Ames Research Center (ARC). There are many problems related to testing large scale semi-span models of high aspect ratio flexible transport wings, such as; floor boundary layer effects, wing spanwise wall effects, solid blockage buoyancy effects, floor mechanical interference effects, airflow under the model effects, or tunnel flow gradient effects. For most of these issues, BCA has developed and implemented either standard testing methods or numerical correction schemes and these will not be discussed in this document. Other researchers have reported on semi-span transonic testing correction issues, however most of the reported research has been for low Mach testing. Some of the reports for low Mach testing address the difficult problem of preventing undesirable airflow under a semi-span model while ensuring unrestricted main balance functionality, however, for transonic models this issue has gone unresolved. BCA has been cognizant for sometime that there are marked differences in wing pressure distributions from semi-span transonic model testing than from full model or flight testing. It has been suspected that these differences are at least in part due to airflow under the model. Previous efforts by BCA to address this issue have proven to be ineffective or inconclusive and in one situation resulted in broken hardware. This paper reports on a Boeing-NASA collaborative investigation based on a series of small tests conducted between June 2006 and November 2007 in the 11 by 11 foot Transonic Wind Tunnel at NASA Ames on three large commercial jet

Investigation of Corner Effect and Identification of Tunneling Regimes in L-Shaped Tunnel Field-Effect-Transistor.

PubMed

Najam, Faraz; Yu, Yun Seop

2018-09-01

Corner-effect existing in L-shaped tunnel field-effect-transistor (LTFET) was investigated using numerical simulations and band diagram analysis. It was found that the corner-effect is caused by the convergence of electric field in the sharp source corner present in an LTFET, thereby increasing the electric field in the sharp source corner region. It was found that in the corner-effect region tunneling starts early, as a function of applied bias, as compared to the rest of the channel not affected by corner-effect. Further, different tunneling regimes as a function of applied bias were identified in the LTFET including source to channel and channel to channel tunneling regimes. Presence of different tunneling regimes in LTFET was analytically justified with a set of equations developed to model source to channel, and channel to channel tunneling currents. Drain-current-gate-voltage (Ids-Vgs) characteristics obtained from the equations is in reasonable qualitative agreement with numerical simulation.

Exploring Resiliency within Schools: An Investigation of the Effects of Protective Factors

ERIC Educational Resources Information Center

Phillips, Matthew D.; Turner, Michael G.; Holt, Thomas J.

2014-01-01

Although research has explored the effects of protective factors on fostering resiliency within "individuals," the same level of inquiry has not emerged investigating the causes of why high-risk "organizations" are resilient to serious violent delinquency. One type of organization that seems particularly appropriate for…

The Effects of High School Organization on Dropping Out: An Exploratory Investigation.

ERIC Educational Resources Information Center

Bryk, Anthony S.; Thum, Yeow Meng

1989-01-01

A hierarchical linear model analysis investigated the effects of structural and normative features of schools on absenteeism and the probability of dropping out. Subjects included 4,450 sophomores in 160 Catholic and public high schools from the High School and Beyond 1980 cohort. (SLD)

Investigation of the Helmholtz-Kohlrausch effect using wide-gamut display

NASA Astrophysics Data System (ADS)

Oh, Semin; Kwak, Youngshin

2015-01-01

The aim of this study is to investigate whether the Helmholtz-Kohlrausch effect exists among the images having various luminance and chroma levels. Firstly, five images were selected. Then each image was adjusted to have 4 different average CIECAM02 C and 5 different average CIECAM02 J. In total 20 test images were generated per each image for the psychophysical experiment. The psychophysical experiment was done in a dark room using a LCD display. To evaluate the overall perceived brightness of images a magnitude estimation method was used. Fifteen participants evaluated the brightness of each image comparing with the reference image. As a result, participants tended to evaluate the brightness higher as the average CIECAM02 J and also CIECAM02 C of the image increases proving the Helmholtz- Kohlrausch effect in images.

An investigation of unsteady 3D effects on trailing edge flaps

NASA Astrophysics Data System (ADS)

Jost, E.; Fischer, A.; Lutz, T.; Krämer, E.

2016-09-01

The present study investigates the impact of unsteady and viscous three-dimensional aerodynamic effects on a wind turbine blade with trailing edge flap by means of CFD. Harmonic oscillations are simulated on the DTU 10 MW rotor with a flap of 10% chord extent ranging from 70% to 80% blade radius. The deflection frequency is varied in the range between 1p and 6p. To quantify 3D effects, rotor simulations are compared to 2D airfoil computations. A significant influence of trailing and shed vortex structures has been found which leads to a reduction of the lift amplitude and hysteresis effects in the lift response with regard to the flap deflection. In the 3D rotor results greater amplitude reductions and less hystereses have been found compared to the 2D airfoil simulations.

An Exploratory Investigation into the Effects of Adaptation in Child-Robot Interaction

NASA Astrophysics Data System (ADS)

Salter, Tamie; Michaud, François; Létourneau, Dominic

The work presented in this paper describes an exploratory investigation into the potential effects of a robot exhibiting an adaptive behaviour in reaction to a child’s interaction. In our laboratory we develop robotic devices for a diverse range of children that differ in age, gender and ability, which includes children that are diagnosed with cognitive difficulties. As all children vary in their personalities and styles of interaction, it would follow that adaptation could bring many benefits. In this abstract we give our initial examination of a series of trials which explore the effects of a fully autonomous rolling robot exhibiting adaptation (through changes in motion and sound) compared to it exhibiting pre-programmed behaviours. We investigate sensor readings on-board the robot that record the level of ‘interaction’ that the robot receives when a child plays with it and also we discuss the results from analysing video footage looking at the social aspect of the trial.

Investigating Strength and Frequency Effects in Recognition Memory Using Type-2 Signal Detection Theory

ERIC Educational Resources Information Center

Higham, Philip A.; Perfect, Timothy J.; Bruno, Davide

2009-01-01

Criterion- versus distribution-shift accounts of frequency and strength effects in recognition memory were investigated with Type-2 signal detection receiver operating characteristic (ROC) analysis, which provides a measure of metacognitive monitoring. Experiment 1 demonstrated a frequency-based mirror effect, with a higher hit rate and lower…

Investigation of the Effects of Teaching Core Exerciseson Young Soccer Players

ERIC Educational Resources Information Center

Yapici, Aysegül

2016-01-01

The objective of this study is to investigate the effects of teaching core exercises on some motoric parameters in young soccer players. 32 amateur male football players from Afjet Afyonspor and Muglaspor football team; 16 experimental group (average age 13.75 ± 0.46 years; mean body height 1.65.± 0.09 cm; mean body mass 52.88 ± 8.04 kg) and 16…

The effect of drawing on children's experiences of investigations following alleged child abuse.

PubMed

Katz, Carmit; Barnetz, Zion; Hershkowitz, Irit

2014-05-01

The primary aim of the study was to evaluate investigative interviews from the perspectives of the children, comparing children who drew with children who did not. One hundred twenty-five children, alleged victims of sexual abuse, were asked about their investigative experience. The uniqueness of the study is that all of the interviews were conducted according to the NICHD Protocol and that children were randomly assigned into one of the two research conditions (drawing vs. non-drawing). The results clearly demonstrate the advantage that drawing has on the children's experience of the investigation, with children in the drawing group more often reporting feelings of hope and success. This study provides practical guidelines for practitioners by emphasizing the beneficial effects that drawing can have. The study stresses the importance of integrating into forensic investigations interventions that enhance children's testimonies and ensure that the investigation is an empowering experience that generates feelings of trust, self-worth, and justice. Copyright © 2014 Elsevier Ltd. All rights reserved.

Spectroscopic investigation of inner filter effect by magnolol solutions

NASA Astrophysics Data System (ADS)

Li, Hongmei; YuzhuHu

2007-12-01

Spectroscopy is useful tool for aggregation studies on fluorephores. One of the major problems with this technique is that the inner filter effect becomes unavoidable since the samples are used at high concentration. In this work, our investigation on magnolol spectroscopic properties shows that the inner filter effect (IFE) of fluorescence plays a critical role in the spectra of magnolol. The strong dependence of the fluorescence parameters on the concentration accounts for the apparent experimental evidence of magnolol aggregation at high concentrations. There are some questions despite the aggregation model based on fluorescent aggregates seems to describe the behavior of the system. The mathematical correction on the emission intensities shows the linear fluorescence-concentration relationship. Furthermore, we propose a mathematic model of excitation spectrum based on the primary IFE (absorption of light of excitation wavelength), which provide a correct explanation of the unusual spectral shift and spectral narrowing in the excitation spectra of magnolol at high concentrations. The shapes of spectra are completely independent on magnolol aggregation and are due only to experimental artifacts, i.e. IFE.

Investigating on the Methodology Effect When Evaluating Lucid Dream

PubMed Central

Ribeiro, Nicolas; Gounden, Yannick; Quaglino, Véronique

2016-01-01

Lucid dreaming (LD) is a state of consciousness in which the dreamer is aware that he or she is dreaming and can possibly control the content of his or her dream. To investigate the LD prevalence among different samples, researchers have used different types of methodologies. With regard to retrospective self-report questionnaire, two ways of proceeding seem to emerge. In one case, a definition of LD is given to participants (“During LD, one is–while dreaming–aware of the fact that one is dreaming. It is possible to deliberately wake up, to control the dream action, or to observe passively the course of the dream with this awareness”), while in the other instances, participants are presented separate questions targeting specific LD indicators (dream awareness and dream control). In the present study, we measured LD frequency in a sample of French student in order to investigate for possible disparities in LD frequency depending on the type of questionnaire as outlined above. Moreover, we also study links between the prevalence of LD as assessed, respectively, by each questionnaire with various factors such as Vividness of Mental Imagery and Parasomnia. Results revealed no significant difference between LD frequencies across questionnaires. For the questionnaire with definition (DefQuest), 81.05% of participants reported experience of LD once or more. Concerning the questionnaire based on LD indicators (AwarContQuest), 73.38% of participants reported having experienced LD once or more. However, with regard to the correlations analysis, links between LD prevalence and factors such as Vividness of Mental Imagery and Parasomnia, varied across questionnaires. This result is an argument suggesting that researchers should be careful when investigating links between LD and other factors. The type of methodology may influence findings on LD research. Further studies are needed to investigate on the methodology effect in LD research namely on the respective weight of

Investigation of the Bystander Effect in School Bullying: Comparison of Experiential, Psychological and Situational Factors

ERIC Educational Resources Information Center

Song, Jiyeon; Oh, Insoo

2017-01-01

The purpose of this study was to investigate whether the "bystander effect" known to occur in emergency situations is effective in bullying situations through examination of the individual experiences of 467 middle- and high-school students. While the bystander effect was not found to be valid in bullying situations, there were…

Investigating the Environmental Effects of Ocean Energy Generation (Invited)

NASA Astrophysics Data System (ADS)

Copping, A. E.; Anderson, R.; Schultz, I.; Woodruff, D.; Carlson, T.; Ward, J.; van Cleve, F.; Eere Mhk Environmental Effects

2010-12-01

damage from specific portions of MHK devices, mooring systems, or electrical cabling. However little is known about the effects of certain MHK stressors such as electromagnetic fields (EMF) from underwater cables and machines, as well as acoustic outputs from rotating turbines. Laboratory investigations into the effects of EMF and acoustics on test organisms will be discussed, and preliminary results presented.

Investigation of Maternal Effects, Maternal-Fetal Interactions and Parent-of-Origin Effects (Imprinting), Using Mothers and Their Offspring

PubMed Central

Ainsworth, Holly F; Unwin, Jennifer; Jamison, Deborah L; Cordell, Heather J

2011-01-01

Many complex genetic effects, including epigenetic effects, may be expected to operate via mechanisms in the inter-uterine environment. A popular design for the investigation of such effects, including effects of parent-of-origin (imprinting), maternal genotype, and maternal-fetal genotype interactions, is to collect DNA from affected offspring and their mothers (case/mother duos) and to compare with an appropriate control sample. An alternative design uses data from cases and both parents (case/parent trios) but does not require controls. In this study, we describe a novel implementation of a multinomial modeling approach that allows the estimation of such genetic effects using either case/mother duos or case/parent trios. We investigate the performance of our approach using computer simulations and explore the sample sizes and data structures required to provide high power for detection of effects and accurate estimation of the relative risks conferred. Through the incorporation of additional assumptions (such as Hardy-Weinberg equilibrium, random mating and known allele frequencies) and/or the incorporation of additional types of control sample (such as unrelated controls, controls and their mothers, or both parents of controls), we show that the (relative risk) parameters of interest are identifiable and well estimated. Nevertheless, parameter interpretation can be complex, as we illustrate by demonstrating the mathematical equivalence between various different parameterizations. Our approach scales up easily to allow the analysis of large-scale genome-wide association data, provided both mothers and affected offspring have been genotyped at all variants of interest. Genet. Epidemiol. 35:19–45, 2011. © 2010 Wiley-Liss, Inc. PMID:21181895

Investigating expectation effects using multiple physiological measures

PubMed Central

Siller, Alexander; Ambach, Wolfgang; Vaitl, Dieter

2015-01-01

The study aimed at experimentally investigating whether the human body can anticipate future events under improved methodological conditions. Previous studies have reported contradictory results for the phenomenon typically called presentiment. If the positive findings are accurate, they call into doubt our views about human perception, and if they are inaccurate, a plausible conventional explanation might be based on the experimental design of the previous studies, in which expectation due to item sequences was misinterpreted as presentiment. To address these points, we opted to collect several physiological variables, to test different randomization types and to manipulate subjective significance individually. For the latter, we combined a mock crime scenario, in which participants had to steal specific items, with a concealed information test (CIT), in which the participants had to conceal their knowledge when interrogated about items they had stolen or not stolen. We measured electrodermal activity, respiration, finger pulse, heart rate (HR), and reaction times. The participants (n = 154) were assigned randomly to four different groups. Items presented in the CIT were either drawn with replacement (full) or without replacement (pseudo) and were either presented category-wise (cat) or regardless of categories (nocat). To understand how these item sequences influence expectation and modulate physiological reactions, we compared the groups with respect to effect sizes for stolen vs. not stolen items. Group pseudo_cat yielded the highest effect sizes, and pseudo_nocat yielded the lowest. We could not find any evidence of presentiment but did find evidence of physiological correlates of expectation. Due to the design differing fundamentally from previous studies, these findings do not allow for conclusions on the question whether the expectation bias is being confounded with presentiment. PMID:26500600

Charge deposition model for investigating SE-microdose effect in trench power MOSFETs

NASA Astrophysics Data System (ADS)

Xin, Wan; Weisong, Zhou; Daoguang, Liu; Hanliang, Bo; Jun, Xu

2015-05-01

It was demonstrated that heavy ions can induce large current—voltage (I-V) characteristics shift in commercial trench power MOSFETs, named single event microdose effect (SE-microdose effect). A model is presented to describe this effect. This model calculates the charge deposition by a single heavy ion hitting oxide and the subsequent charge transport under an electric field. Holes deposited at the SiO2/Si interface by a Xe ion are calculated by using this model. The calculated results were then used in Sentaurus TCAD software to simulate a trench power MOSFET's I-V curve shift after a Xe ion has hit it. The simulation results are consistent with the related experiment's data. In the end, several factors which affect the SE-microdose effect in trench power MOSFETs are investigated by using this model.

Investigating the Effects of Planning Time on the Complexity of L2 Argumentative Writing

ERIC Educational Resources Information Center

Tabari, Mahmoud Abdi

2017-01-01

Much research has investigated the role of planning time in second language writing; however, the results show that there are inconsistent findings about the effects of planning time conditions on the complexity of the EFL learners' textual output. The current study attempted to consider the differential effects of planning time conditions in…

A Qualitative Investigation into the Characteristics and Effects of Music Accompanying Exercise

ERIC Educational Resources Information Center

Priest, David-Lee; Karageorghis, Costas I.

2008-01-01

The purpose of the present study was to identify the characteristics of music used to accompany physical exercise and investigate the effects of such music using a qualitative approach. This work underpins the further development of a theoretical structure that is still relatively new. Semi-structured interviews were conducted with a sample of…

The need for investigations to elucidate causes and effects of abnormal uterine bleeding.

PubMed

Munro, Malcolm G; Heikinheimo, Oskari; Haththotuwa, Rohana; Tank, Jaydeep D; Fraser, Ian S

2011-09-01

This article describes a modern perspective on the basic investigations for abnormal uterine bleeding (AUB) in low-resource settings compared with a much more detailed approach for high-resource settings, bearing in mind issues of effectiveness and cost effectiveness. AUB includes any one or more of several symptoms, and it should be evaluated for the characteristics of the woman's specific bleeding pattern, her "complaint" and the presence of other symptoms (especially pain), the impact on several aspects of body functioning and lifestyle, and the underlying cause(s), especially cancer. Ideally, the evaluation is comprehensive, considering each of the potential etiological domains defined by the International Federation of Gynecology and Obstetrics PALM-COEIN system for the classification of causes. However, the detail of the questions and the extent of investigations will be significantly influenced by the technologies available and the time allotted for a consultation. In general, investigations should be performed only if they will make a material difference to the management approaches that can be offered. This should be an important consideration when a range of costly high-technology tests is accessible or when certain tests only have limited availability. © Thieme Medical Publishers.

Investigation of Sooting in Microgravity Droplet Combustion: Fuel-Dependent Effects

NASA Technical Reports Server (NTRS)

Manzello, Samuel L.; Hua, Ming; Choi, Mun Young

1999-01-01

Kumagai and coworkers first performed microgravity droplet combustion experiments [Kumagai, 1957]. The primary goal of these early experiments were to validate simple 'd(sup 2)-law models [Spalding, 1954, Godsave, 1954] Inherent in the 'd(sup 2) -law' formulation and in the scope of the experimental observation is the neglect of sooting behavior. In fact, the influence of sooting has not received much attention until more recent works [Choi et al., 1990; Jackson et al., 1991; Jackson and Avedisian, 1994; Choi and Lee, 1996; Jackson and Avedisian, 1996; Lee et al., 1998]:. Choi and Lee measured soot volume fraction for microgravity droplet flames using full-field light extinction and subsequent tomographic inversion [Choi and Lee, 1996]. In this investigation, soot concentrations were measured for heptane droplets and it was reported that soot concentrations were considerably higher in microgravity compared to the normal gravity flame. It was reasoned that the absence of buoyancy and the effects of thermophoresis resulted in the higher soot concentrations. Lee et al. [1998] performed soot measurement experiments by varying the initial droplet diameter and found marked influence of sooting on the droplet burning behavior. There is growing sentiment that sooting in droplet combustion must no longer be neglected and that "perhaps one of the most important outstanding contributions of (micro)g droplet combustion is the observation that in the absence of asymmetrical forced and natural convection, a soot shell is formed between the droplet surface and the flame, exerting an influence on the droplet combustion response far greater than previously recognized." [Law and Faeth, 1994]. One of the methods that we are exploring to control the degree of sooting in microgravity is to use different fuels. The effect of fuel structure on sooting propensity has been investigated for over-ventilated concentric coflowing buoyant diffusion flames. (Glassman, 1996]. In these

Investigating strength and frequency effects in recognition memory using type-2 signal detection theory.

PubMed

Higham, Philip A; Perfect, Timothy J; Bruno, Davide

2009-01-01

Criterion- versus distribution-shift accounts of frequency and strength effects in recognition memory were investigated with Type-2 signal detection receiver operating characteristic (ROC) analysis, which provides a measure of metacognitive monitoring. Experiment 1 demonstrated a frequency-based mirror effect, with a higher hit rate and lower false alarm rate, for low frequency words compared with high frequency words. In Experiment 2, the authors manipulated item strength with repetition, which showed an increased hit rate but no effect on the false alarm rate. Whereas Type-1 indices were ambiguous as to whether these effects were based on a criterion- or distribution-shift model, the two models predict opposite effects on Type-2 distractor monitoring under some assumptions. Hence, Type-2 ROC analysis discriminated between potential models of recognition that could not be discriminated using Type-1 indices alone. In Experiment 3, the authors manipulated Type-1 response bias by varying the number of old versus new response categories to confirm the assumptions made in Experiments 1 and 2. The authors conclude that Type-2 analyses are a useful tool for investigating recognition memory when used in conjunction with more traditional Type-1 analyses.

An Investigation into the Effectiveness of Problem-Based Learning in a Physical Chemistry Laboratory Course

ERIC Educational Resources Information Center

Gurses, Ahmet; Acikyildiz, Metin; Dogar, Cetin; Sozbilir, Mustafa

2007-01-01

The aim of this study was to investigate the effectiveness of a problem-based learning (PBL) approach in a physical chemistry laboratory course. The parameters investigated were students' attitudes towards a chemistry laboratory course, scientific process skills of students and their academic achievement. The design of the study was one group…

Investigating Aerobic, Anaerobic Combine Technical Trainings' Effects on Performance in Tennis Players

ERIC Educational Resources Information Center

Suna, Gürhan; Kumartasli, Mehmet

2017-01-01

The aim of this study is to investigate eight-week aerobic, anaerobic combine technical trainings' effects on developments of performance. 21 athletes of tennis proficiency students from Sports Sciences Department were joined to the study voluntarily. Participated in the research athletes' ages' mean was 22,2 ± 0,3 year, lengths' mean was 177,3 ±…

Using Time-Series Research Designs to Investigate the Effects of Instruction on SLA.

ERIC Educational Resources Information Center

Mellow, J. Dean; And Others

1996-01-01

Argues that the study of second-language acquisition theory can be enhanced through time-series research designs. Within the context of investigating the effects of second-language instruction, four main reasons for using T-S design are identified. (95 references) (Author/CK)

NASA MSU Status Report. [Research on high T(sub c) superconducting compounds

NASA Technical Reports Server (NTRS)

Oliver, Frederick W.

1995-01-01

Our laboratory concentrations consisted of several parts: (1) we made several presentations of the work sponsored by NASA covered under the last status report period; (2) we irradiated and successfully completed Moessbauer measurements on a high temperature superconductor; (3) we continued the improvement of our laboratory with the development of improved software; and (4) we made modifications of equipment to increase the efficiency and decrease the time necessary for completing an experimental investigation. In addition to our research results, this report contains a copy of the last financial report submitted by the University's business office that was related to this grant.

Investigation of Fully Three-Dimensional Helical RF Field Effects on TWT Beam/Circuit Interaction

NASA Technical Reports Server (NTRS)

Kory, Carol L.

2000-01-01

A fully three-dimensional (3D), time-dependent, helical traveling wave-tube (TWT) interaction model has been developed using the electromagnetic particle-in-cell (PIC) code MAFIA. The model includes a short section of helical slow-wave circuit with excitation fed by RF input/output couplers, and electron beam contained by periodic permanent magnet (PPM) focusing. All components of the model are simulated in three dimensions allowing the effects of the fully 3D helical fields on RF circuit/beam interaction to be investigated for the first time. The development of the interaction model is presented, and predicted TWT performance using 2.5D and 3D models is compared to investigate the effect of conventional approximations used in TWT analyses.

Investigating Experimental Effects within the Framework of Structural Equation Modeling: An Example with Effects on Both Error Scores and Reaction Times

ERIC Educational Resources Information Center

Schweizer, Karl

2008-01-01

Structural equation modeling provides the framework for investigating experimental effects on the basis of variances and covariances in repeated measurements. A special type of confirmatory factor analysis as part of this framework enables the appropriate representation of the experimental effect and the separation of experimental and…

Experimental investigations of driving frequency effect in low-pressure capacitively coupled oxygen discharges

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

Liu, Jia; Liu, Yong-Xin; Liu, Gang-Hu

2015-04-14

The effect of driving frequency on the electron density is investigated in low-pressure capacitively coupled oxygen plasmas by utilizing a floating hairpin probe. The power absorbed by the plasma is investigated and it is found that the power lost in the matching network can reach 50% or higher under certain conditions. The effect of driving frequency on the electron density is studied from two aspects, i.e., constant absorbed power and electrode voltage. In the former case, the electron density increases with the driving frequency increasing from 13.56 to 40.68 MHz and slightly changes depending on the gas pressures with the frequencymore » further increasing to 100 MHz. In the latter case, the electron density rapidly increases when the driving frequency increases from 13.56 to 40.68 MHz, and then decreases with the frequency further increasing to 100 MHz. The electron series resonance is observed at 40.68 MHz and can be attributed to the higher electron density. And the standing wave effect also plays an important role in increasing electron density at 100 MHz and 2.6 Pa.« less

Investigation of Solvation Effects on Optical Rotatory Dispersion Using the Polarizable Continuum Model

NASA Astrophysics Data System (ADS)

Aharon, Tal; Lemler, Paul M.; Vaccaro, Patrick; Caricato, Marco

2017-06-01

The Optical Rotatory Dispersion (ORD) of a chiral solute is heavily affected by solvation, but this effect does not follow the usual correlation with the solvent polarity, i.e., larger solvent polarity does not imply a larger change in the solute's property. Therefore, a great deal of experimental and theoretical effort has been directed towards correlating the solvation effect on the ORD and the solvent properties. This discovery followed from the development of cavity ring down polarimetry (CRPD), which allows measurements of gas-phase ORD. In order to investigate this phenomenon, we chose a set of five rigid molecules to limit the effect of molecular vibrations and isolate the role of solvation. The latter was investigated with the Polarizable Continuum Model (PCM), and compared to experimental results. We used Bondi radii to build the PCM cavity, and performed extensive calculations at multiple frequencies using density functional theory (DFT) with two functionals: B3LYP and CAM-B3LYP, together with the aug-cc-pVDZ basis set. We also performed coupled cluster singles and doubles (CCSD/aug-cc-pVDZ) calculations at the wavelengths where gas-phase data are available, all of which are augmented with zero point vibrational corrections. These results are compared to experimental data and seem to indicate that PCM does not entirely account for the environmental effects on the ORD.

Investigation into the effects of VHF and UHF band radiation on Hewlett-Packard (HP) Cesium Beam Frequency Standards

NASA Technical Reports Server (NTRS)

Dickens, Andrew

1995-01-01

This paper documents an investigation into reports which have indicated that exposure to VHF and UHF band radiation has adverse effects on the frequency stability of HP cesium beam frequency standards. Tests carried out on the basis of these reports show that sources of VHF and UHF radiation such as two-way hand held police communications devices do cause reproducible adverse effects. This investigation examines reproducible effects and explores possible causes.

Robotic investigation on effect of stretch reflex and crossed inhibitory response on bipedal hopping

PubMed Central

Rosendo, Andre; Ikemoto, Shuhei; Shimizu, Masahiro; Hosoda, Koh

2018-01-01

To maintain balance during dynamic locomotion, the effects of proprioceptive sensory feedback control (e.g. reflexive control) should not be ignored because of its simple sensation and fast reaction time. Scientists have identified the pathways of reflexes; however, it is difficult to investigate their effects during locomotion because locomotion is controlled by a complex neural system and current technology does not allow us to change the control pathways in living humans. To understand these effects, we construct a musculoskeletal bipedal robot, which has similar body structure and dynamics to those of a human. By conducting experiments on this robot, we investigate the effects of reflexes (stretch reflex and crossed inhibitory response) on posture during hopping, a simple and representative bouncing gait with complex dynamics. Through over 300 hopping trials, we confirm that both the stretch reflex and crossed response can contribute to reducing the lateral inclination during hopping. These reflexive pathways do not use any prior knowledge of the dynamic information of the body such as its inclination. Beyond improving the understanding of the human neural system, this study provides roboticists with biomimetic ideas for robot locomotion control. PMID:29593088

A virtual experimenter to increase standardization for the investigation of placebo effects.

PubMed

Horing, Bjoern; Newsome, Nathan D; Enck, Paul; Babu, Sabarish V; Muth, Eric R

2016-07-18

Placebo effects are mediated by expectancy, which is highly influenced by psychosocial factors of a treatment context. These factors are difficult to standardize. Furthermore, dedicated placebo research often necessitates single-blind deceptive designs where biases are easily introduced. We propose a study protocol employing a virtual experimenter - a computer program designed to deliver treatment and instructions - for the purpose of standardization and reduction of biases when investigating placebo effects. To evaluate the virtual experimenter's efficacy in inducing placebo effects via expectancy manipulation, we suggest a partially blinded, deceptive design with a baseline/retest pain protocol (hand immersions in hot water bath). Between immersions, participants will receive an (actually inert) medication. Instructions pertaining to the medication will be delivered by one of three metaphors: The virtual experimenter, a human experimenter, and an audio/text presentation (predictor "Metaphor"). The second predictor includes falsely informing participants that the medication is an effective pain killer, or correctly informing them that it is, in fact, inert (predictor "Instruction"). Analysis will be performed with hierarchical linear modelling, with a sample size of N = 50. Results from two pilot studies are presented that indicate the viability of the pain protocol (N = 33), and of the virtual experimenter software and placebo manipulation (N = 48). It will be challenging to establish full comparability between all metaphors used for instruction delivery, and to account for participant differences in acceptance of their virtual interaction partner. Once established, the presence of placebo effects would suggest that the virtual experimenter exhibits sufficient cues to be perceived as a social agent. He could consequently provide a convenient platform to investigate effects of experimenter behavior, or other experimenter characteristics, e.g., sex, age

Experimental and Numerical Investigations of Constraint Effect on Deformation Behavior of Tailor-Welded Blanks

NASA Astrophysics Data System (ADS)

Li, Yanhua; Lin, Jianping

2015-08-01

Tailor-welded blanks (TWBs) have been considered as a productive sheet forming method in automotive industries. However, formability of TWBs is reduced due to different properties or thicknesses of the blanks and is a challenge for manufacturing designers. The plastic capacity of TWBs is decreased even when the material and thickness are the same. The constraint effect of the laser weld (including weld and heat-affected zone) material in the forming process of similar TWBs is a key problem to be solved in the research, development and application of thin-sheet TWBs. In this paper, uniaxial tensile tests with full-field strain measurement by digital image correlation and Erichsen tests are performed to investigate the constraint effect on deformation behavior and explore the mechanism of decreasing formability of similar TWBs. In addition, finite element models are conducted under ABAQUS code to further reveal the phenomenal behavior of the constraint effect. The results of the base material and welded blanks are compared for characterizing the differences. Furthermore, in order to better understand this mechanism, theoretical and numerical investigations are employed and compared to interpret the constraint effect of laser weld on the deformation behavior of TWBs. An index is proposed to quantify the constraint effect. Results show that the constraint effect of laser weld appears in both stretch forming and drawing of TWBs. Strain paths are approaching the plane strain condition as compared to the monolithic blank due to the constraint effect. Constraint effect is a major factor affecting the formability of TWBs when the failure occurs away from the weld seam.

Investigating the Role of Collective Trust, Collective Efficacy, and Enabling School Structures on Overall School Effectiveness

ERIC Educational Resources Information Center

Gray, Julie

2016-01-01

This study investigated the role of collective trust, collective efficacy, and enabling school structures on overall school effectiveness. While the concept of organizational effectiveness can be complex and difficult to measure, the results of this research demonstrated a connection of these variables to school effectiveness. Collective trust had…

Investigation of some effects of humidity on aerodynamic characteristics on a 10-percent-thick NASA supercritical airfoil

NASA Technical Reports Server (NTRS)

Jordan, F. L., Jr.

1976-01-01

An investigation was conducted in the Langley 8-foot transonic pressure tunnel to determine the effects of wind-tunnel humidity on the aerodynamic characteristics of a 10-percent-thick NASA supercritical airfoil. Effects of dewpoint variation from 267 K (20 F) to 294 K (70 F) were investigated. The tunnel stagnation temperature was 322 K (120 F) and the stagnation pressure was 0.1013 MN/09 m (1 atm).

Investigating Effect of Origami-Based Instruction on Elementary Students' Spatial Skills and Perceptions

ERIC Educational Resources Information Center

Cakmak, Sedanur; Isiksal, Mine; Koc, Yusuf

2014-01-01

The authors' purpose was to investigate the effect of origami-based instruction on elementary students' spatial ability. The students' self-reported perceptions related to the origami-based instruction were also examined. Data was collected via purposive sampling techniques from students enrolled in a private elementary school. A spatial ability…

Investigation on deterrence effect of legal punishment measures on driving after drinking in Chongqing, China.

PubMed

Suo, Qinghui

2015-01-01

Driving after drinking is one of the main causes associated with road accidents in China. China has been concerned about this serious problem and updated the regulations of road traffic safety law about driving after drinking 3 times in the last 10 years to deter this offense. The deterrence effect of the current punishment measures implemented since January 2013 was studied in this article. Data applied in the study were collected by questionnaire surveys carried out in Chongqing, a city in southwest China. A total of 329 drivers participated in 3 rounds of the survey and a 5-point scale rating was applied in the investigation. There was a slight difference between drivers' familiarity of the law regarding driving after drinking in April 2013 and April 2014. The perceived certainty of being caught for driving after drinking was higher in April 2013 than in April 2014 and it had a time-dependent decreasing tendency. Our investigations also show that license suspension is the most practical and effective measure and penalty points system ranks second. A monetary fine appears to be inefficient to achieve the desired effects. The fourth edition of the Road Traffic Safety Law of the People's Republic of China, which took effect in January 2013 coinciding with the application of random breath testing and intensification of enforcement activity, is effective in deterring driving after drinking according to our investigation. More measures should be implemented to change the decreasing tendency of perceived certainty of being caught for driving after drinking. An increase in the monetary fine is suggested.

Success with Investigations.

ERIC Educational Resources Information Center

Chin, Christine

2003-01-01

Describes strategies for facilitating student science investigations and alleviating common weaknesses associated with student performance. Includes checklist criteria for performance on investigative tasks and an example of an assessment rubric for the investigation of the effect of temperature on enzyme activity. (Author/KHR)

Investigations of some building materials for γ-rays shielding effectiveness

NASA Astrophysics Data System (ADS)

Mann, Kulwinder Singh; Kaur, Baljit; Sidhu, Gurdeep Singh; Kumar, Ajay

2013-06-01

For construction of residential and non-residential buildings bricks are used as building blocks. Bricks are made from mixtures of sand, clay, cement, fly ash, gypsum, red mud and lime. Shielding effectiveness of five soil samples and two fly ash samples have been investigated using some energy absorption parameters (Mass attenuation coefficients, mass energy absorption coefficients, KERMA (kinetic energy released per unit mass), HVL, equivalent atomic number and electron densities) firstly at 14 different energies from 81-1332 keV then extended to wide energy range 0.015-15 MeV. The soil sample with maximum shielding effectiveness has been used for making eight fly ash bricks [(Lime)0.15 (Gypsum)0.05 (Fly Ash)x (Soil)0.8-x, where values of x are from 0.4-0.7]. High Purity Germanium (HPGe) detector has been used for gamma-ray spectroscopy. The elemental compositions of samples were analysed using an energy dispersive X-ray fluorescence (EDXRF) spectrometer. The agreements of theoretical and experimental values of mass attenuation coefficient have been found to be quite satisfactory. It has been verified that common brick possess the maximum shielding effectiveness for wide energy range 0.015-15 MeV. The results have been shown graphically with some useful conclusions for making radiation safe buildings.

An Investigation of the Partial-Assignment Completion Effect on Students' Assignment Choice Behavior

ERIC Educational Resources Information Center

Hawthorn-Embree, Meredith L.; Skinner, Christopher H.; Parkhurst, John; Conley, Elisha

2011-01-01

This study was designed to investigate the partial assignment completion effect. Seventh-grade students were given a math assignment. After working for 5 min, they were interrupted and their partially completed assignments were collected. About 20 min later, students were given their partially completed assignment and a new, control assignment…

Computational Investigations on the Effects of Gurney Flap on Airfoil Aerodynamics.

PubMed

Jain, Shubham; Sitaram, Nekkanti; Krishnaswamy, Sriram

2015-01-01

The present study comprises steady state, two-dimensional computational investigations performed on NACA 0012 airfoil to analyze the effect of Gurney flap (GF) on airfoil aerodynamics using k-ε RNG turbulence model of FLUENT. Airfoil with GF is analyzed for six different heights from 0.5% to 4% of the chord length, seven positions from 0% to 20% of the chord length from the trailing edge, and seven mounting angles from 30° to 120° with the chord. Computed values of lift and drag coefficients with angle of attack are compared with experimental values and good agreement is found at low angles of attack. In addition static pressure distribution on the airfoil surface and pathlines and turbulence intensities near the trailing edge are present. From the computational investigation, it is recommended that Gurney flaps with a height of 1.5% chord be installed perpendicular to chord and as close to the trailing edge as possible to obtain maximum lift enhancement with minimum drag penalty.

Computational Investigations on the Effects of Gurney Flap on Airfoil Aerodynamics

PubMed Central

Jain, Shubham; Sitaram, Nekkanti; Krishnaswamy, Sriram

2015-01-01

The present study comprises steady state, two-dimensional computational investigations performed on NACA 0012 airfoil to analyze the effect of Gurney flap (GF) on airfoil aerodynamics using k-ε RNG turbulence model of FLUENT. Airfoil with GF is analyzed for six different heights from 0.5% to 4% of the chord length, seven positions from 0% to 20% of the chord length from the trailing edge, and seven mounting angles from 30° to 120° with the chord. Computed values of lift and drag coefficients with angle of attack are compared with experimental values and good agreement is found at low angles of attack. In addition static pressure distribution on the airfoil surface and pathlines and turbulence intensities near the trailing edge are present. From the computational investigation, it is recommended that Gurney flaps with a height of 1.5% chord be installed perpendicular to chord and as close to the trailing edge as possible to obtain maximum lift enhancement with minimum drag penalty. PMID:27347517

Investigating the Effectiveness of Speech-To-Text Recognition Applications on Learning Performance, Attention, and Meditation

ERIC Educational Resources Information Center

Shadiev, Rustam; Huang, Yueh-Min; Hwang, Jan-Pan

2017-01-01

In this study, the effectiveness of the application of speech-to-text recognition (STR) technology on enhancing learning and concentration in a calm state of mind, hereafter referred to as meditation (An intentional and self-regulated focusing of attention in order to relax and calm the mind), was investigated. This effectiveness was further…

Effects of video-game play on information processing: a meta-analytic investigation.

PubMed

Powers, Kasey L; Brooks, Patricia J; Aldrich, Naomi J; Palladino, Melissa A; Alfieri, Louis

2013-12-01

Do video games enhance cognitive functioning? We conducted two meta-analyses based on different research designs to investigate how video games impact information-processing skills (auditory processing, executive functions, motor skills, spatial imagery, and visual processing). Quasi-experimental studies (72 studies, 318 comparisons) compare habitual gamers with controls; true experiments (46 studies, 251 comparisons) use commercial video games in training. Using random-effects models, video games led to improved information processing in both the quasi-experimental studies, d = 0.61, 95% CI [0.50, 0.73], and the true experiments, d = 0.48, 95% CI [0.35, 0.60]. Whereas the quasi-experimental studies yielded small to large effect sizes across domains, the true experiments yielded negligible effects for executive functions, which contrasted with the small to medium effect sizes in other domains. The quasi-experimental studies appeared more susceptible to bias than were the true experiments, with larger effects being reported in higher-tier than in lower-tier journals, and larger effects reported by the most active research groups in comparison with other labs. The results are further discussed with respect to other moderators and limitations in the extant literature.

New PANDA Tests to Investigate Effects of Light Gases on Passive Safety Systems

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

Paladino, D.; Auban, O.; Candreia, P.

The large- scale thermal-hydraulic PANDA facility (located at PSI in Switzerland), has been used over the last few years for investigating different passive decay- heat removal systems and containment phenomena for the next generation of light water reactors (Simplified Boiling Water Reactor: SBWR; European Simplified Boiling Water Reactor: ESBWR; Siedewasserreaktor: SWR-1000). Currently, as part of the European Commission 5. EURATOM Framework Programme project 'Testing and Enhanced Modelling of Passive Evolutionary Systems Technology for Containment Cooling' (TEMPEST), a new series of tests is being planned in the PANDA facility to experimentally investigate the distribution of non-condensable gases inside the containment andmore » their effect on the performance of the 'Passive Containment Cooling System' (PCCS). Hydrogen release caused by the metal-water reaction in the case of a postulated severe accident will be simulated in PANDA by injecting helium into the reactor pressure vessel. In order to provide suitable data for Computational Fluid Dynamic (CFD) code assessment and improvement, the instrumentation in PANDA has been upgraded for the new tests. In the present paper, a detailed discussion is given of the new PANDA tests to be performed to investigate the effects of light gas on passive safety systems. The tests are scheduled for the first half of the year 2002. (authors)« less

Wind-Tunnel Investigation of the Effect of Tab Balance on Tab and Control-Surface Characteristics

NASA Technical Reports Server (NTRS)

Brewer, Jack D; Queijo, M J

1947-01-01

An investigation was conducted to furnish data on the effect of tab balance on tab and control-surface characteristics. The airfoil tested had a modified NACA 65(1)-012 contour with a plain flap having a chord equal to 25 percent of the wing chord and with a tab having a chord equal to 25 percent of the flap chord and having several nose shapes and overhang lengths. The results of the investigation indicated that, in general, tab balance affected tab hinge-moment characteristics in much the same manner that flap balance affects flap hinge-moment characteristics. A moderate amount of tab balance did not seem to have any adverse effect on flap hinge-moment characteristics.

The etiology and drug therapy of kinesia: investigations by means of the coriolis effect under cyclizine.

PubMed

Reicke, N

1976-01-01

The typical symptoms of kinesia were produced in 30 healthy test subjects by means of the Coriolis effect and the effect of cyclizine upon them was investigated in a single blind trial. The drug showed a clear effect on the autonomic symptoms (nausea) while there was no evidence of inhibition of the peripheral vestibular function.

Energy investigation of effects of O on mechanical properties of NiAl intermetallics.

PubMed

Hu, Xue-Lan; Liu, Li-Hua; Zhang, Ying; Lu, Guang-Hong; Wang, Tianmin

2011-01-19

We have investigated effects of O on mechanical properties of NiAl by calculating the cleavage energy (γ(C)) and the unstable stacking fault energy (γ(us)) using a first-principles method. O is shown to reduce γ(C)/γ(us) for the [001](110) and [100](001) slip systems, indicating that the presence of O should be associated with the ductility reduction of NiAl. Further, γ(C)/γ(us) of the NiAl-O system can be increased by Cr, suggesting the possibility to suppress the negative effect of O via alloying elements.

Portevin-Le Chatelier effect under cyclic loading: experimental and numerical investigations

NASA Astrophysics Data System (ADS)

Mazière, M.; Pujol d'Andrebo, Q.

2015-10-01

The Portevin-Le Chatelier (PLC) effect is generally evidenced by the apparition of serrated yielding under monotonic tensile loading conditions. It appears at room temperature in some aluminium alloys, around ? in some steels and in many other metallic materials. This effect is associated with the propagation of bands of plastic deformation in tensile specimens and can in some cases lead to unexpected failures. The PLC effect has been widely simulated under monotonic conditions using finite elements and an appropriate mechanical model able to reproduce serrations and strain localization. The occurrence of serrations can be predicted using an analytical stability analysis. Recently, this serrated yielding has also been observed in specimens made of Cobalt-based superalloy under cyclic loading, after a large number of cycles. The mechanical model has been identified in this case to accurately reproduce this critical number of cycle where serrations appear. The associated apparition of localized bands of deformation in specimens and their influence on its failure has also been investigated using finite element simulations.

Investigation of the effects of color on judgments of sweetness using a taste adaptation method.

PubMed

Hidaka, Souta; Shimoda, Kazumasa

2014-01-01

It has been reported that color can affect the judgment of taste. For example, a dark red color enhances the subjective intensity of sweetness. However, the underlying mechanisms of the effect of color on taste have not been fully investigated; in particular, it remains unclear whether the effect is based on cognitive/decisional or perceptual processes. Here, we investigated the effect of color on sweetness judgments using a taste adaptation method. A sweet solution whose color was subjectively congruent with sweetness was judged as sweeter than an uncolored sweet solution both before and after adaptation to an uncolored sweet solution. In contrast, subjective judgment of sweetness for uncolored sweet solutions did not differ between the conditions following adaptation to a colored sweet solution and following adaptation to an uncolored one. Color affected sweetness judgment when the target solution was colored, but the colored sweet solution did not modulate the magnitude of taste adaptation. Therefore, it is concluded that the effect of color on the judgment of taste would occur mainly in cognitive/decisional domains.

Investigating message-framing effects in the context of a tailored intervention promoting physical activity.

PubMed

van 't Riet, Jonathan; Ruiter, Robert A C; Werrij, Marieke Q; de Vries, Hein

2010-04-01

Health-promoting messages can be framed in terms of the gains associated with healthy behaviour or the losses associated with unhealthy behaviour. It has been argued that gain-framed messages promoting physical activity (PA) are more effective than loss-framed messages, but empirical findings are inconsistent. Also, no previous studies investigated the effects of gain- and loss-framed messages in the context of a computer-tailored PA intervention. In this study, we provided participants with computer-generated tailored feedback concerning their PA levels. In total, 787 participants entered in the study, of whom 299 completed all measures at a 3-month follow-up. We investigated whether gain- and loss-framed messages promoting PA affected information acceptance, attitude, intention and behaviour differently. The results showed that gain-framed messages resulted in stronger intentions to be physically active than loss-framed messages. This did not result in a significant increase in actual PA, however, as measured by a 3-month follow-up assessment. For information acceptance and attitude, a non-significant advantage of gain-framed messages was found. All effects had small effect sizes. Thus, whereas gain-framed information might be more persuasive than loss-framed information when it comes to promoting PA, the differences between gain- and loss-framed messages are likely to be small.

Long-term memory color investigation: culture effect and experimental setting factors.

PubMed

Zhu, Yuteng; Luo, Ming Ronnier; Fischer, Sebastian; Bodrogi, Peter; Khanh, Tran Quoc

2017-10-01

Memory colors generated continuous interest in the color community. Previous studies focused on reflecting color chips and color samples in real scenes or on monitors. The cognitive effect of culture was rarely considered. In this paper, we performed a comprehensive investigation of the long-term memory colors of 26 familiar objects using the asymmetric color matching method among Chinese and German observers on a display. Three experiments were conducted to evaluate the variations introduced by culture, context-based gray image, and initial matching color. Memory colors of important objects were collected and representative memory colors were quantified in terms of CIELAB L * , a * , and b * values. The intra- and inter-observer variations were analyzed by mean-color-difference-from-mean values and chromatic ellipses. The effects of different cultural groups and experimental settings were also shown.

Investigation of the effects of magnetic field exposure on human melatonin. Interim report

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

Graham, C.; Cook, M.R.; Cohen, H.D.

Several rodent studies have suggested that magnetic field exposure may alter the daily pattern of melatonin secretion. This study investigated melatonin levels in mean exposed overnight to magnetic fields of 10 mG and 200 mG. The study also assessed the potential effects of exposure on a number of performance and self-reported endpoints in the subjects. Investigation of this area is important, as altered diurnal melatonin cycles have been linked to a variety of endpoints, including reproductive outcome, neurobehavioral function, and carcinogenesis. The results of this investigation did not support the a priori hypothesis that exposure to 60-Hz magnetic fields ofmore » 10 mG and 200 mG alters nighttime melatonin levels in a population of adult males. However, the data suggested the possibility of differential sensitivity to magnetic fields based on an individual`s baseline melatonin level.« less

Optical investigation of effective permeability of dilute magnetic dielectrics with magnetic field

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

Banerjee, Ananya, E-mail: banerjee.ananya2008@gmail.com; Sarkar, A.

The prime objective of this paper is to investigate the magnetic nature of dilute magnetic dielectrics (DMD) under variation of external magnetic field. The said variation is studied over developed nano-sized Gadolinium Oxide as a DMD system. The observed experimental field variation of the effective magnetic permeability is analyzed results of optical experiment. The experiment records the variation of Brewster angle of incident polarized LASER beam from the surface of developed DMD specimen with applied out of plane external magnetic field. The effective refractive index and hence relative magnetic permeability were estimated following electro-magnetic theory. The overall results obtained andmore » agreement between theory and experiment are good.« less

Using a Cell Phone to Investigate the Skin Depth Effect in Salt Water

NASA Astrophysics Data System (ADS)

Rayner, John

2017-02-01

This paper describes an experimental investigation of the skin depth effect for electromagnetic waves in salt water using a cell phone that is immersed to a critical depth where it no longer responds when called. We show that this critical depth is directly proportional to the theoretical skin depth for a range of salt concentrations.

Using a Cell Phone to Investigate the Skin Depth Effect in Salt Water

ERIC Educational Resources Information Center

Rayner, John

2017-01-01

This paper describes an experimental investigation of the skin depth effect for electromagnetic waves in salt water using a cell phone that is immersed to a critical depth where it no longer responds when called. We show that this critical depth is directly proportional to the theoretical skin depth for a range of salt concentrations.

A preliminary investigation into the neural basis of the production effect.

PubMed

Hassall, Cameron D; Quinlan, Chelsea K; Turk, David J; Taylor, Tracy L; Krigolson, Olave E

2016-06-01

Items that are produced (e.g., read aloud) during encoding typically are better remembered than items that are not produced (e.g., read silently). This "production effect" has been explained by distinctiveness: Produced items have more distinct features than nonproduced items, leading to enhanced retrieval. The goal of the current study was to use electroencephalography (EEG) to examine the neural basis of the production effect. During study, participants were presented with words that they were required to read silently, read aloud, or sing while EEG data were recorded. Subsequent memory performance was tested using a yes/no recognition test. Analysis focused on the event-related brain potentials (ERPs) evoked by the encoding instruction cue for each instruction condition. Our data revealed enhanced memory performance for produced items and a greater P300 ERP amplitude for instructions to sing or read aloud compared with instructions to read silently. Our results demonstrate that the amplitude of the P300 is modulated by at least 1 aspect of production, vocalization (singing/reading aloud relative to reading silently), and are consistent with the distinctiveness account of the production effect. The ERP methodology is a viable tool for investigating the production effect. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

A Transmission Electron Microscope Investigation of Space Weathering Effects in Hayabusa Samples

NASA Technical Reports Server (NTRS)

Keller, Lindsay P.; Berger, Eve L.

2014-01-01

The Hayabusa mission to asteroid 25143 Itokawa successfully returned the first direct samples of the regolith from the surface of an asteroid. The Hayabusa samples thus present a special opportunity to directly investigate the evolution of asteroidal surfaces, from the development of the regolith to the study of the more complex effects of space weathering. Here we describe the mineralogy, microstructure and composition of three Hayabusa mission particles using transmission electron microscope (TEM) techniques

Investigation of Portevin-Le Chatelier effect in 5456 Al-based alloy using digital image correlation

NASA Astrophysics Data System (ADS)

Cheng, Teng; Xu, Xiaohai; Cai, Yulong; Fu, Shihua; Gao, Yue; Su, Yong; Zhang, Yong; Zhang, Qingchuan

2015-02-01

A variety of experimental methods have been proposed for Portevin-Le Chatelier (PLC) effect. They mainly focused on the in-plane deformation. In order to achieve the high-accuracy measurement, three-dimensional digital image correlation (3D-DIC) was employed in this work to investigate the PLC effect in 5456 Al-based alloy. The temporal and spatial evolutions of deformation in the full field of specimen surface were observed. The large deformation of localized necking was determined experimentally. The distributions of out-of-plane displacement over the loading procedure were also obtained. Furthermore, a comparison of measurement accuracy between two-dimensional digital image correlation (2D-DIC) and 3D-DIC was also performed. Due to the theoretical restriction, the measurement accuracy of 2D-DIC decreases with the increase of deformation. A maximum discrepancy of about 20% with 3D-DIC was observed in this work. Therefore, 3D-DIC is actually more essential for the high-accuracy investigation of PLC effect.

Investigating the effect of cardiac oscillations and deadspace gas mixing during apnea using computer simulation.

PubMed

Laviola, Marianna; Das, Anup; Chikhani, Marc; Bates, Declan G; Hardman, Jonathan G

2017-07-01

Gaseous mixing in the anatomical deadspace with stimulation of respiratory ventilation through cardiogenic oscillations is an important physiological mechanism at the onset of apnea, which has been credited with various beneficial effects, e.g. reduction of hypercapnia during the use of low flow ventilation techniques. In this paper, a novel method is proposed to investigate the effect of these mechanisms in silico. An existing computational model of cardio-pulmonary physiology is extended to include the apneic state, gas mixing within the anatomical deadspace, insufflation into the trachea and cardiogenic oscillations. The new model is validated against data published in an experimental animal (dog) study that reported an increase in arterial partial pressure of carbon dioxide (PaCO 2 ) during apnea. Computational simulations confirm that the model outputs accurately reproduce the available experimental data. This new model can be used to investigate the physiological mechanisms underlying clearance of carbon dioxide during apnea, and hence to develop more effective ventilation strategies for apneic patients.

Giant piezoelectric size effects in zinc oxide and gallium nitride nanowires. A first principles investigation.

PubMed

Agrawal, Ravi; Espinosa, Horacio D

2011-02-09

Nanowires made of materials with noncentrosymmetric crystal structure are under investigation for their piezoelectric properties and suitability as building blocks for next-generation self-powered nanodevices. In this work, we investigate the size dependence of piezoelectric coefficients in nanowires of two such materials - zinc oxide and gallium nitride. Nanowires, oriented along their polar axis, ranging from 0.6 to 2.4 nm in diameter were modeled quantum mechanically. A giant piezoelectric size effect is identified for both GaN and ZnO nanowires. However, GaN exhibits a larger and more extended size dependence than ZnO. The observed size effect is discussed in the context of charge redistribution near the free surfaces leading to changes in local polarization. The study reveals that local changes in polarization and reduction of unit cell volume with respect to bulk values lead to the observed size effect. These results have strong implication in the field of energy harvesting, as piezoelectric voltage output scales with the piezoelectric coefficient.

Monotonic non-linear transformations as a tool to investigate age-related effects on brain white matter integrity: A Box-Cox investigation.

PubMed

Morozova, Maria; Koschutnig, Karl; Klein, Elise; Wood, Guilherme

2016-01-15

Non-linear effects of age on white matter integrity are ubiquitous in the brain and indicate that these effects are more pronounced in certain brain regions at specific ages. Box-Cox analysis is a technique to increase the log-likelihood of linear relationships between variables by means of monotonic non-linear transformations. Here we employ Box-Cox transformations to flexibly and parsimoniously determine the degree of non-linearity of age-related effects on white matter integrity by means of model comparisons using a voxel-wise approach. Analysis of white matter integrity in a sample of adults between 20 and 89years of age (n=88) revealed that considerable portions of the white matter in the corpus callosum, cerebellum, pallidum, brainstem, superior occipito-frontal fascicle and optic radiation show non-linear effects of age. Global analyses revealed an increase in the average non-linearity from fractional anisotropy to radial diffusivity, axial diffusivity, and mean diffusivity. These results suggest that Box-Cox transformations are a useful and flexible tool to investigate more complex non-linear effects of age on white matter integrity and extend the functionality of the Box-Cox analysis in neuroimaging. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of garlic extract on spreading depression: In vitro and in vivo investigations.

PubMed

Marschollek, Claudia; Karimzadeh, Fariba; Jafarian, Maryam; Ahmadi, Milad; Mohajeri, Seyed Mohammad Reza; Rahimi, Sadegh; Speckmann, Erwin-Josef; Gorji, Ali

2017-02-01

The potential use of garlic for prevention and treatment of different types of headaches has been suggested by several medieval literatures. Cortical spreading depression (CSD), a propagating wave of neuroglial depolarization, was established as a target for anti-migraine drugs. This study was designed to investigate the effect of garlic extract on CSD in adult rats. CSD was induced by KCl microinjection in the somatosensory cortex. The effects of five different concentrations of garlic oil (1-500 μl/l) were tested on different characteristic features of CSD in necocortical slices. In in vivo experiments, the effects of garlic oil on electrophysiological and morphological changes induced by CSD were investigated. Garlic oil in a dose-dependent manner decreased the amplitude of CSD but not its duration and velocity in neocortical brain slices. Garlic oil at concentration of 500 μl/l reversibly reduced the amplitude of the field excitatory post-synaptic potentials and inhibited induction of long-term potentiation in the third layer of neocortical slices. In in vivo studies, systemic application of garlic oil (1 ml/l) for three consecutive days reduced the amplitude and repetition rate of CSD. Garlic oil also prevented of CSD-induced reactive astrocytosis in the neocortex. Garlic oil suppresses CSD, likely via inhibition of synaptic plasticity, and prevents its harmful effects on astrocyte. Further studies are required to identify the exact active ingredient(s) of garlic oil that inhibit CSD and may have the potential to use in treatment of CSD-related disorders.

Investigating the effect of m-commerce design usability on customers' trust

NASA Astrophysics Data System (ADS)

Hussain, Azham Bin; Mahmood, Alaa Thamer; Naser, Raed Kamil

2017-10-01

User experience may vary from one user to another based on the design characteristics for processing a certain task. Our review of the literature revealed that there is a noticeable lack of studies on the effect of mobile or m-commerce design usability on customers' trust to perform certain activities. We investigated the effect of m-commerce design usability in terms of navigability, supportability, readability, creditability, and content relevant. A close-ended questionnaire was distributed to 20 customers who were asked to perform some tasks. The result showed that majority of the participants found m-commerce design usability to influence their trust of the app. The mentioned usability elements were found to positively influence customers' trust except for supportability. Our findings provide some insights to the m-commerce designers and developers and extend the current understanding about the potential of design usability in explaining users' usage behavior.

Investigation into the Effects of Microsecond Power Line Transients on Line-Connected Capacitors

NASA Technical Reports Server (NTRS)

Javor, K.

2000-01-01

An investigation was conducted into the effect of power-line transients on capacitors used by NASA and installed on platform primary power inputs to avionics. The purpose was to investigate whether capacitor voltage ratings needs to be derated for expected spike potentials. Concerns had been voiced in the past by NASA suppliers that MIL-STD-461 CS06-like requirements were overly harsh and led to physically large capacitors. The author had previously predicted that electrical-switching spike requirements representative of actual power-line transient potentials, durations. and source impedance would require no derating. This investigation bore out that prediction. It was further determined that traditional low source impedance CS06-like transients also will not damage a capacitor, although the spikes themselves are not nearly as well filtered. This report should be used to allay fears that CS06-like requirements drive capacitor voltage derating. Only that derating required by the relatively long duration transients in power quality specification need concern the equipment designer.

Investigation Into The Effects of Microsecond Power Line Transients On Line-Connected Capacitors

NASA Technical Reports Server (NTRS)

Javor, Ken

1999-01-01

An investigation was conducted into the effect of power-line transients on capacitors used by NASA and installed on platform primary power inputs to avionics. The purpose was to investigate whether capacitor voltage rating needs to be derated for expected spike potentials. Concerns had been voiced in the past by NASA suppliers that MIL-STD-461 CS06-like requirements were overly harsh and led to physically large capacitors. The author had previously predicted that electrical-switching spike requirements representative of actual power-line transient potentials, durations and source impedance would require no derating. This investigation bore out that prediction. It was further determined that traditional low source impedance CS06-like transients also will not damage a capacitor, although the spikes themselves are not nearly as well filtered. This report should be used to allay fears that CS06-like requirements drive capacitor voltage derating. Only that derating required by the relatively long duration transients in power quality specification need concern the equipment designer.

The Effects of Issue Investigation and Action Training on Eighth-Grade Students' Environmental Behavior.

ERIC Educational Resources Information Center

Ramsey, John M.

1993-01-01

Reports the instructional effects of a formal environmental education methodology, issue investigation and action training (IIAT), on eighth-grade students. Focuses on whether IIAT can improve responsible environmental behavior in middle school students and whether variables associated with responsible adult environmental behavior will be…

Experimental investigation on IXV TPS interface effects in Plasmatron

NASA Astrophysics Data System (ADS)

Ceglia, Giuseppe; Trifoni, Eduardo; Gouriet, Jean-Baptiste; Chazot, Olivier; Mareschi, Vincenzo; Rufolo, Giuseppe; Tumino, Giorgio

2016-06-01

An experimental investigation related to the thermal protection system (TPS) interfaces of the intermediate experimental vehicle has been carried out in the Plasmatron facility at the von Karman Institute for fluid dynamics. The objective of this test campaign is to qualify the thermal behaviours of two different TPS interfaces under flight representative conditions in terms of heat flux and integral heat load ( 180 kW/m2 for 700 s). Three test samples are tested in off-stagnation configuration installed on an available flat plate holder under the same test conditions. The first junction is composed of an upstream ceramic matrix composite (CMC) plate and an ablative P50 cork composite block separated by a gap of 2 mm. The second one is made of an upstream P50 block and a downstream ablative SV2A silicon elastomer block with silicon-based filler in between. A sample composed of P50 material is tested in order to obtain reference results without TPS interface effect. The overheating at the CMC-P50 interface due to the jump of the catalytic properties of the materials, and the recession/swelling behaviour of the P50-SV2A interface are under investigation. All the test samples withstand relatively well the imposed heat flux for the test duration. As expected, both the ablative materials undergo a thermal degradation. The P50 exhibits the formation of a porous char layer and its recession; on the other hand, the SV2A swells and forms a fragile char layer.

Experimental Investigations on the effect of Additive on the Tensile Properties of Fiber Glass Fabric Lamina

NASA Astrophysics Data System (ADS)

Nava Sai Divya, A.; Raghu Kumar, B., Dr; Lakshmi Narayana, G., Dr

2017-09-01

The main objective of this work is to investigate the effect of additives on tensile behaviour of fiber glass fabric at lamina level to explore an alternative skin material for the outer body of aerospace applications and machines. This experimental work investigates the effect of silica concentration in epoxy resin lapox L-12 on the tensile properties of glass fabric lamina of 4H-satin weave having 3.6 mm thickness. The lamina was prepared by using hand lay-up method and tests were conducted on it. Various tensile properties values obtained from experimentation were compared for four glass fiber lamina composites fabricated by adding the silica powder to resin bath. The effect of variations in silica concentration (0% SiO2, 5% SiO2, 10% SiO2 and 15% SiO2) on the tensile properties of prepared material revealed that maximum stiffness was obtained at 15% and yield strength at 10% SiO2 concentration in glass fiber lamina. Increasing the silica concentration beyond 10% had led to deterioration in the material properties. The experimentation that was carried out on test specimen was reasonably successful as the effect of silica powder as an additive in glass fiber lamina enhanced the mechanical properties up to certain limit. The underpinning microscopic behaviour at the source of these observations will be investigated in a follow up work.

The Effects of Teachers’ Motivational Strategies on Learners’ Motivation: A Controlled Investigation of Second Language Acquisition

ERIC Educational Resources Information Center

Moskovsky, Christo; Alrabai, Fakieh; Paolini, Stefania; Ratcheva, Silvia

2013-01-01

While consensus exists about the critical role of learners’ motivation in second language acquisition, controlled investigations of the effects of teachers’ motivational strategies are limited. The research reported here used a quasi-experimental design to assess the effects of motivational strategies used by Saudi English as a foreign language…

Is the Factor Observed in Investigations on the Item-Position Effect Actually the Difficulty Factor?

PubMed

Schweizer, Karl; Troche, Stefan

2018-02-01

In confirmatory factor analysis quite similar models of measurement serve the detection of the difficulty factor and the factor due to the item-position effect. The item-position effect refers to the increasing dependency among the responses to successively presented items of a test whereas the difficulty factor is ascribed to the wide range of item difficulties. The similarity of the models of measurement hampers the dissociation of these factors. Since the item-position effect should theoretically be independent of the item difficulties, the statistical ex post manipulation of the difficulties should enable the discrimination of the two types of factors. This method was investigated in two studies. In the first study, Advanced Progressive Matrices (APM) data of 300 participants were investigated. As expected, the factor thought to be due to the item-position effect was observed. In the second study, using data simulated to show the major characteristics of the APM data, the wide range of items with various difficulties was set to zero to reduce the likelihood of detecting the difficulty factor. Despite this reduction, however, the factor now identified as item-position factor, was observed in virtually all simulated datasets.

Investigation on the cavitation effect of underwater shock near different boundaries

NASA Astrophysics Data System (ADS)

Xiao, Wei; Wei, Hai-peng; Feng, Liang

2017-08-01

When the shock wave of underwater explosion propagates to the surfaces of different boundaries, it gets reflected. Then, a negative pressure area is formed by the superposition of the incident wave and reflected wave. Cavitation occurs when the value of the negative pressure falls below the vapor pressure of water. An improved numerical model based on the spectral element method is applied to investigate the cavitation effect of underwater shock near different boundaries, mainly including the feature of cavitation effect near different boundaries and the influence of different parameters on cavitation effect. In the implementation of the improved numerical model, the bilinear equation of state is used to deal with the fluid field subjected to cavitation, and the field separation technique is employed to avoid the distortion of incident wave propagating through the mesh and the second-order doubly asymptotic approximation is applied to simulate the non-reflecting boundary. The main results are as follows. As the peak pressure and decay constant of shock wave increases, the range of cavitation domain increases, and the duration of cavitation increases. As the depth of water increases, the influence of cavitation on the dynamic response of spherical shell decreases.

Experimental investigation on the effects of swirling flow on augmentor performance

NASA Astrophysics Data System (ADS)

Tan, Haoyuan; Huang, Xianjian

1991-06-01

This paper describes an investigation on the effect of centrifugal force distributions on swirl augmentor performance. The experiments were conducted on the flow drag, temperature-distribution efficiency in the swirl augmentor model with different tangential velocity profiles. Four tangential velocity distributions considered are the Rankine vortex, forced vortex, free vortex, and the constant-angle vortex. The results show that the flow drag of the Rankine vortex swirler is the smallest one, and, in a swirl augmentor where flame is stabilized by using centrifugal force, the combustion efficiency can reach 90 percent or over, though the swirl number is low (S = 0.25).

Investigation of Trends in Aerosol Direct Radiative Effects over North America Using a Coupled Meteorology-Chemistry Model

EPA Science Inventory

A comprehensive investigation of the processes regulating tropospheric aerosol distributions, their optical properties, and their radiative effects in conjunction with verification of their simulated radiative effects for past conditions relative to measurements is needed in orde...

Investigating relativity using lunar laser ranging - Geodetic precession and the Nordtvedt effect

NASA Technical Reports Server (NTRS)

Dickey, J. O.; Newhall, X. X.; Williams, J. G.

1989-01-01

The emplacement of retroreflectors on the moon by Apollo astronauts and the Russian Lunakhod spacecraft marked the inception of lunar laser ranging (LLR) and provided a natural laboratory for the study of general relativity. Continuing acquisition of increasingly accurate LLR data has provided enhanced sensitivity to general relativity parameters. Two relativistic effects are investigated in this paper: (1) the Nordtvedt effect, yielding a test of the strong equivalence principle, would appear as a distortion of the geocentric lunar orbit in the direction of the sun. The inclusion of recent LLR data limits the size of any such effect to 3 + or - 4 cm. The sensitivities to the various PPN quantities are also highlighted. (2) the geodetic precession of the lunar perigee is predicted by general relativity as a consequence of the motion of the earth-moon system about the sun; its theoretical magnitude is 19.2 mas/yr. Analysis presented here confirms this value and determines this quality to a 2 percent level.

Preliminary investigation on the effects of primary airflow to coal particle distribution in coal-fired boilers

NASA Astrophysics Data System (ADS)

Noor, N. A. W. Mohd; Hassan, H.; Hashim, M. F.; Hasini, H.; Munisamy, K. M.

2017-04-01

This paper presents an investigation on the effects of primary airflow to coal fineness in coal-fired boilers. In coal fired power plant, coal is pulverized in a pulverizer, and it is then transferred to boiler for combustion. Coal need to be ground to its desired size to obtain maximum combustion efficiency. Coarse coal particle size may lead to many performance problems such as formation of clinker. In this study, the effects of primary airflow to coal particles size and coal flow distribution were investigated by using isokinetic coal sampling and computational fluid dynamic (CFD) modelling. Four different primary airflows were tested and the effects to resulting coal fineness were recorded. Results show that the optimum coal fineness distribution is obtained at design primary airflow. Any reduction or increase of air flow rate results in undesirable coal fineness distribution.

Investigating the Effect of Origami Instruction on Preservice Teachers' Spatial Ability and Geometric Knowledge for Teaching

ERIC Educational Resources Information Center

Akayuure, Peter; Asiedu-Addo, S. K.; Alebna, Victor

2016-01-01

Whereas origami is said to have pedagogical benefits in geometry education, research is inclusive about its effect on spatial ability and geometric knowledge among preservice teachers. The study investigated the effect of origami instruction on these aspects using pretest posttest quasi-experiment design. The experimental group consisted of 52…

Numerical investigation of adhesion effects on solid particles filtration efficiency

NASA Astrophysics Data System (ADS)

Shaffee, Amira; Luckham, Paul; Matar, Omar K.

2017-11-01

Our work investigate the effectiveness of particle filtration process, in particular using a fully-coupled Computational Fluid Dynamics (CFD) and Discrete Element Method (DEM) approach involving poly-dispersed, adhesive solid particles. We found that an increase in particle adhesion reduces solid production through the opening of a wire-wrap type filter. Over time, as particle agglomerates continuously deposit on top of the filter, layer upon layer of particles is built on top of the filter, forming a particle pack. It is observed that with increasing particle adhesion, the pack height build up also increases and hence decreases the average particle volume fraction of the pack. This trend suggests higher porosity and looser packing of solid particles within the pack with increased adhesion. Furthermore, we found that the pressure drop for adhesive case is lower compared to non-adhesive case. Our results suggest agglomerating solid particles has beneficial effects on particle filtration. One important application of these findings is towards designing and optimizing sand control process for a hydrocarbon well with excessive sand production which is major challenge in oil and gas industry. Funding from PETRONAS and RAEng UK for Research Chair (OKM) gratefully acknowledged.

Investigation of microgravity effects on solidification phenomena of selected materials

NASA Technical Reports Server (NTRS)

Maag, Carl R.; Hansen, Patricia A.

1992-01-01

A Get Away Special (GAS) experiment payload to investigate microgravity effects on solidification phenomena of selected experimental samples has been designed for flight. It is intended that the first flight of the assembly will (1) study the p-n junction characteristics for advancing semiconductor device applications, (2) study the effects of gravity-driven convection on the growth of HgCd crystals, (3) compare the textures of the sample which crystallizes in microgravity with those found in chondrite meteorites, and (4) modify glass optical characteristics through divalent oxygen exchange. The space flight experiment consists of many small furnaces. While the experiment payload is in the low gravity environment of orbital flight, the payload controller will sequentially activate the furnaces to heat samples to their melt state and then allow cooling to resolidification in a controlled fashion. The materials processed in the microgravity environment of space will be compared to the same materials processed on earth in a one-gravity environment. This paper discusses the design of all subassemblies (furnance, electronics, and power systems) in the experiment. A complete description of the experimental materials is also presented.

Auditory Contagious Yawning in Humans: An Investigation into Affiliation and Status Effects

PubMed Central

Massen, Jorg J. M.; Church, Allyson M.; Gallup, Andrew C.

2015-01-01

While comparative research on contagious yawning has grown substantially in the past few years, both the interpersonal factors influencing this response and the sensory modalities involved in its activation in humans remain relatively unknown. Extending upon previous studies showing various in-group and status effects in non-human great apes, we performed an initial study to investigate how the political affiliation (Democrat vs. Republican) and status (high vs. low) of target stimuli influences auditory contagious yawning, as well as the urge to yawn, in humans. Self-report responses and a subset of video recordings were analyzed from 118 undergraduate students in the US following exposure to either breathing (control) or yawning (experimental) vocalizations paired with images of former US Presidents (high status) and their respective Cabinet Secretaries of Commerce (low status). The overall results validate the use of auditory stimuli to prompt yawn contagion, with greater response in the experimental than the control condition. There was also a negative effect of political status on self-reported yawning and the self-reported urge to yawn irrespective of the condition. In contrast, we found no evidence for a political affiliation bias in this response. These preliminary findings are discussed in terms of the existing comparative evidence, though we highlight limitations in the current investigation and we provide suggestions for future research in this area. PMID:26617557

Investigating the Effect of Syrian Refugees on the Pharmaceutical Sector in Jordan.

PubMed

Daher, Amirah; Alabbadi, Ibrahim

2017-08-01

The aim of this study was to investigate the effect of Syrian refugees on the pharmaceutical sector in Jordan. Based on a standardized methodology developed by the WHO, Level II Facility (2009) structured questionnaires (including: medicine access [availability, affordability and geographical accessibility], quality, and rational use of medicines) were used to investigate the effect of Syrian refugees influx on the pharmaceutical sector in Jordan. Lists of essential medicines (N = 50) were included in the survey forms. The results showed more progress in all indicators for the public sector compared with the previous results in the 2009 survey and in comparison to the private sector. For example, access to medicines improved in the public sector while it decreased (if it did not remain the same) in the private sector. Also, average stock out duration time decreased dramatically in both public and private sectors. As indicated by the median price ratio (MPR), brand prices increased much in the public health facilities while they decreased by 23%-30% in the private sector. In northern areas where most Syrian refugees stay, a significant decrease in availability was noticed, in addition to the dramatic decrease in days of average stock out and adequate inventory record percentage of those medicines. In conclusion, despite the international help received to support health care provision and medications procurement for the refugees, more support is needed immediately.

Investigating the effects of critical phenomena in premixed methane-oxygen flames at cryogenic conditions

NASA Astrophysics Data System (ADS)

Gopal, Abishek; Yellapantula, Shashank; Larsson, Johan

2017-11-01

Methane is increasingly becoming viable as a rocket fuel in the latest generation of launch vehicles. In liquid rocket engines, fuel and oxidizer are injected under cryogenic conditions into the combustion chamber. At high pressures, typical of rocket combustion chambers, the propellants exist in supercritical states where the ideal gas thermodynamics are no longer valid. We investigate the effects of real-gas thermodynamics on transcritical laminar premixed methane-oxygen flames. The effect of the real-gas cubic equations of state and high-pressure transport properties on flame dynamics is presented. We also study real-gas effects on the extinction limits of the methane-oxygen flame.

Spectroscopic investigation of the constituent components effect on the biodegradable package characteristics

NASA Astrophysics Data System (ADS)

Coťa, C.; Cioica, N.; Filip, C.; Fechete, R.; Todica, M.; Nagy, E. M.; Cozar, O.

2015-12-01

The effect of the nature and the content of the plasticizers (water, glycerol) on the corn starch based biodegradable packages properties (crystalline-amorphous) and also on their degradation process after absorption of distilled water were investigated by 1H NMR relaxation and 13C CP/MAS NMR spectroscopies. For this goal, a set of 14 samples with various starch/glycerol/water (mass %) ratios were prepared and investigated after extrusion process in order to establish their crystalline or amorphous character. The composition having starch/glycerol/water 68/17/15 mass % ratio was found to have a dominant amorphous character and very similar features with a commercial specimen (USA) used for the package. It was also found that this best package is extremely degraded after just one day under water absorption. The most resistant package was that with a large content of starch (78/19.5/2.5).

Structural investigations and the effect of strain on lead based double perovskites

NASA Astrophysics Data System (ADS)

Abbett, Brian; Fennie, Craig J.

2014-03-01

The A2 BB' O6 double perovskite structure, in which the B and B' ions are ordered (typically in a rocksalt configuration), provides a versatile platform to realize new properties such as multiferroicity. In particular, compounds with a lone-pair cation on the A-site, such as A=Pb2+, and magnetic B=Co, Mn, and diamagnetic B'= Te, Mo, W, Re, cations have been investigated experimentally, but as of yet none have been found to display ferroelectricity, although several are known to be antiferroelectric. Here we present a first-principles study of the structural and dielectric properties of this family of compounds. We resolve any conflicting reports in the literature as to the ground state structure of compounds and predict the ground state structure when no structural data is available. Additionally, we investigate the effect of epitaxial strain on the structural and magnetic properties.

Investigating the Effect of Reduced Forms Instruction on EFL Learners' Listening and Speaking Abilities

ERIC Educational Resources Information Center

Khaghaninezhad, Mohammad Saber; Jafarzadeh, Ghasem

2014-01-01

Listening comprehension is usually considered as one of the most difficult language skills to EFL learners due to the unavoidable presence of "reduced forms" in authentic speech. This study was an attempt to investigate the effect of explicit "reduced forms" instruction on Iranian EFL learners' overall listening comprehension…

A Naturalistic Investigation of Media Multitasking While Studying and the Effects on Exam Performance

ERIC Educational Resources Information Center

Patterson, Michael C.

2017-01-01

The present study investigated the use of multiple digital media technologies, including social networking platforms, by students while preparing for an examination (media multitasking) and the subsequent effects on exam performance. The level of media multitasking (number of simultaneous media technologies) and duration of study were used as…

Effectiveness of PowerPoint-Based Lectures across Different Business Disciplines: An Investigation and Implications

ERIC Educational Resources Information Center

Burke, Lisa A.; James, Karen; Ahmadi, Mohammad

2009-01-01

The authors investigated business faculty members' degree of Power-Point (PPT) use across different functional areas in a business program and their use of specific PPT features. The authors also examined students' perceptions of PPT's effectiveness across different business courses (e.g., accounting, economics, management, business law,…

Investigation of Magnetotelluric Source Effect Based on Twenty Years of Telluric and Geomagnetic Observation

NASA Astrophysics Data System (ADS)

Kis, A.; Lemperger, I.; Wesztergom, V.; Menvielle, M.; Szalai, S.; Novák, A.; Hada, T.; Matsukiyo, S.; Lethy, A. M.

2016-12-01

Magnetotelluric method is widely applied for investigation of subsurface structures by imaging the spatial distribution of electric conductivity. The method is based on the experimental determination of surface electromagnetic impedance tensor (Z) by surface geomagnetic and telluric registrations in two perpendicular orientation. In practical explorations the accurate estimation of Z necessitates the application of robust statistical methods for two reasons:1) the geomagnetic and telluric time series' are contaminated by man-made noise components and2) the non-homogeneous behavior of ionospheric current systems in the period range of interest (ELF-ULF and longer periods) results in systematic deviation of the impedance of individual time windows.Robust statistics manage both load of Z for the purpose of subsurface investigations. However, accurate analysis of the long term temporal variation of the first and second statistical moments of Z may provide valuable information about the characteristics of the ionospheric source current systems. Temporal variation of extent, spatial variability and orientation of the ionospheric source currents has specific effects on the surface impedance tensor. Twenty year long geomagnetic and telluric recordings of the Nagycenk Geophysical Observatory provides unique opportunity to reconstruct the so called magnetotelluric source effect and obtain information about the spatial and temporal behavior of ionospheric source currents at mid-latitudes. Detailed investigation of time series of surface electromagnetic impedance tensor has been carried out in different frequency classes of the ULF range. The presentation aims to provide a brief review of our results related to long term periodic modulations, up to solar cycle scale and about eventual deviations of the electromagnetic impedance and so the reconstructed equivalent ionospheric source effects.

Investigating the Effectiveness of Audio Input Enhancement on EFL Learners' Retention of Intensifiers

ERIC Educational Resources Information Center

Negari, Giti Mousapour; Azizi, Aliye; Arani, Davood Khedmatkar

2018-01-01

The present study attempted to investigate the effects of audio input enhancement on EFL learners' retention of intensifiers. To this end, two research questions were formulated. In order to address these research questions, this study attempted to reject two null hypotheses. Pretest-posttest control group quasi-experimental design was employed to…

Investigating the Effects of Multimedia Input Modality on L2 Listening Skills of Turkish EFL Learners

ERIC Educational Resources Information Center

Inceçay, Volkan; Koçoglu, Zeynep

2017-01-01

The present study examined whether or not different input delivery modes have an effect on listening comprehension of Turkish students learning English at the university level. It investigated the effect of one single mode, which is audio-only, and three dual input delivery modes, which were audio-video, audio-video with target language subtitles…

Investigation of temporal vascular effects induced by focused ultrasound treatment with speckle-variance optical coherence tomography

PubMed Central

Tsai, Meng-Tsan; Chang, Feng-Yu; Lee, Cheng-Kuang; Gong, Cihun-Siyong Alex; Lin, Yu-Xiang; Lee, Jiann-Der; Yang, Chih-Hsun; Liu, Hao-Li

2014-01-01

Focused ultrasound (FUS) can be used to locally and temporally enhance vascular permeability, improving the efficiency of drug delivery from the blood vessels into the surrounding tissue. However, it is difficult to evaluate in real time the effect induced by FUS and to noninvasively observe the permeability enhancement. In this study, speckle-variance optical coherence tomography (SVOCT) was implemented for the investigation of temporal effects on vessels induced by FUS treatment. With OCT scanning, the dynamic change in vessels during FUS exposure can be observed and studied. Moreover, the vascular effects induced by FUS treatment with and without the presence of microbubbles were investigated and quantitatively compared. Additionally, 2D and 3D speckle-variance images were used for quantitative observation of blood leakage from vessels due to the permeability enhancement caused by FUS, which could be an indicator that can be used to determine the influence of FUS power exposure. In conclusion, SVOCT can be a useful tool for monitoring FUS treatment in real time, facilitating the dynamic observation of temporal effects and helping to determine the optimal FUS power. PMID:25071945

Theoretical investigation of performance of armchair graphene nanoribbon field effect transistors.

PubMed

Hur, Ji-Hyun; Kim, Deok-Kee

2018-05-04

In this paper, we theoretically investigate the highest possible expected performance for graphene nanoribbon field effect transistors (GNRFETs) for a wide range of operation voltages and device structure parameters, such as the width of the graphene nanoribbon and gate length. We formulated a self-consistent, non-equilibrium Green's function method in conjunction with the Poisson equation and modeled the operation of nanometer sized GNRFETs, of which GNR channels have finite bandgaps so that the GNRFET can operate as a switch. We propose a metric for competing with the current silicon CMOS high performance or low power devices and explain that this can vary greatly depending on the GNRFET structure parameters.

Theoretical investigation of performance of armchair graphene nanoribbon field effect transistors

NASA Astrophysics Data System (ADS)

Hur, Ji-Hyun; Kim, Deok-Kee

2018-05-01

In this paper, we theoretically investigate the highest possible expected performance for graphene nanoribbon field effect transistors (GNRFETs) for a wide range of operation voltages and device structure parameters, such as the width of the graphene nanoribbon and gate length. We formulated a self-consistent, non-equilibrium Green’s function method in conjunction with the Poisson equation and modeled the operation of nanometer sized GNRFETs, of which GNR channels have finite bandgaps so that the GNRFET can operate as a switch. We propose a metric for competing with the current silicon CMOS high performance or low power devices and explain that this can vary greatly depending on the GNRFET structure parameters.

An Experimental Investigation Into The Effect Of Plasma On The Flow Features Of An Axisymmetric Jet

DTIC Science & Technology

2007-10-01

document contains color images. 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18 . NUMBER OF PAGES 386...Prescribed by ANSI Std Z39- 18 AN EXPERIMENTAL INVESTIGATION INTO THE EFFECT OF PLASMA ON THE FLOW FEATURES OF AN AXISYMMETRIC JET BY RICHARD E. HUFFMAN...A. 18 Comparison of Plasma Effects on Skewness and Kurtosis: Case 611LINE3051 . . . . . . . . . 223 A.19 Comparison of Plasma Effects on Mean Velocity

Investigation of piezoresistive effect in p-channel metal–oxide–semiconductor field-effect transistors fabricated on circular silicon-on-insulator diaphragms using cost-effective minimal-fab process

NASA Astrophysics Data System (ADS)

Liu, Yongxun; Tanaka, Hiroyuki; Umeyama, Norio; Koga, Kazuhiro; Khumpuang, Sommawan; Nagao, Masayoshi; Matsukawa, Takashi; Hara, Shiro

2018-06-01

P-channel metal–oxide–semiconductor field-effect transistors (PMOSFETs) with the 〈110〉 or 〈100〉 channel direction have been successfully fabricated on circular silicon-on-insulator (SOI) diaphragms using a cost-effective minimal-fab process, and their electrical characteristics have been systematically investigated before and after the SOI diaphragm formation. It was found that almost the same subthreshold slope (S-slope) and threshold voltage (V t) are observed in the fabricated PMOSFETs before and after the SOI diaphragm formation, and they are independent of the channel direction. On the other hand, significant variations in drain current were observed in the fabricated PMOSFETs with the 〈110〉 channel direction after the SOI diaphragm formation owing to the residual mechanical stress-induced piezoresistive effect. It was also confirmed that electrical characteristics of the fabricated PMOSFETs with the 〈100〉 channel direction are almost the same before and after the SOI diaphragm formation, i.e., not sensitive to the mechanical stress. Moreover, the drain current variations at different directions of mechanical stress and current flow were systematically investigated and discussed.

Are Intelligence Tests Measurement Invariant over Time? Investigating the Nature of the Flynn Effect

ERIC Educational Resources Information Center

Wicherts, Jelte M.; Dolan, Conor V.; Hessen, David J.; Oosterveld, Paul; van Baal, G. Caroline M.; Boomsma, Dorret I.; Span, Mark M.

2004-01-01

The gains of scores on standardized intelligence tests (i.e., Flynn effect) have been the subject of extensive debate concerning their nature, causes, and implications. The aim of the present study is to investigate whether five intelligence tests are measurement invariant with respect to cohort. Measurement invariance implies that gains over the…

Spectroscopic investigation of the constituent components effect on the biodegradable package characteristics

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

Coţa, C.; Cioica, N., E-mail: cioica@inma.ro; Nagy, E. M.

The effect of the nature and the content of the plasticizers (water, glycerol) on the corn starch based biodegradable packages properties (crystalline-amorphous) and also on their degradation process after absorption of distilled water were investigated by {sup 1}H NMR relaxation and {sup 13}C CP/MAS NMR spectroscopies. For this goal, a set of 14 samples with various starch/glycerol/water (mass %) ratios were prepared and investigated after extrusion process in order to establish their crystalline or amorphous character. The composition having starch/glycerol/water 68/17/15 mass % ratio was found to have a dominant amorphous character and very similar features with a commercial specimenmore » (USA) used for the package. It was also found that this best package is extremely degraded after just one day under water absorption. The most resistant package was that with a large content of starch (78/19.5/2.5)« less

Investigating How Contact Angle Effects the Interaction between Water and a Hydrophobic Surface

NASA Astrophysics Data System (ADS)

Poynor, Adele; Neidig, Caitlyn

2012-02-01

By definition hydrophobic substances hate water. What happens when water is forced into contact with a hydrophobic surface? One theory is that an ultra-thin low-density region forms near the surface. Contact angle is a measure of how hydrophobic a surface is. We have employed an automated home-built Surface Plasmon Resonance (SPR) apparatus to investigate the effect of varying the contact angle on the depletion layer

Effect of Calcifications on Breast Ultrasound Shear Wave Elastography: An Investigational Study

PubMed Central

Gregory, Adriana; Mehrmohammadi, Mohammad; Denis, Max; Bayat, Mahdi; Stan, Daniela L.; Fatemi, Mostafa; Alizad, Azra

2015-01-01

Purpose To investigate the effects of macrocalcifications and clustered microcalcifications associated with benign breast masses on shear wave elastography (SWE). Methods SuperSonic Imagine (SSI) and comb-push ultrasound shear elastography (CUSE) were performed on three sets of phantoms to investigate how calcifications of different sizes and distributions influence measured elasticity. To demonstrate the effect in vivo, three female patients with benign breast masses associated with mammographically-identified calcifications were evaluated by CUSE. Results Apparent maximum elasticity (Emax) estimates resulting from individual macrocalcifications (with diameters of 2mm, 3mm, 5mm, 6mm, 9mm, 11mm, and 15mm) showed values over 50 kPa for all cases, which represents more than 100% increase over background (~21kPa). We considered a 2cm-diameter circular region of interest for all phantom experiments. Mean elasticity (Emean) values varied from 26 kPa to 73 kPa, depending on the macrocalcification size. Highly dense clusters of microcalcifications showed higher Emax values than clusters of microcalcification with low concentrations, but the difference in Emean values was not significant. Conclusions Our results demonstrate that the presence of large isolated macrocalcifications and highly concentrated clusters of microcalcifications can introduce areas with apparent high elasticity in SWE. Considering that benign breast masses normally have significantly lower elasticity values than malignant tumors, such areas with high elasticity appearing due to presence of calcification in benign breast masses may lead to misdiagnosis. PMID:26368939

Effect of Calcifications on Breast Ultrasound Shear Wave Elastography: An Investigational Study.

PubMed

Gregory, Adriana; Mehrmohammadi, Mohammad; Denis, Max; Bayat, Mahdi; Stan, Daniela L; Fatemi, Mostafa; Alizad, Azra

2015-01-01

To investigate the effects of macrocalcifications and clustered microcalcifications associated with benign breast masses on shear wave elastography (SWE). SuperSonic Imagine (SSI) and comb-push ultrasound shear elastography (CUSE) were performed on three sets of phantoms to investigate how calcifications of different sizes and distributions influence measured elasticity. To demonstrate the effect in vivo, three female patients with benign breast masses associated with mammographically-identified calcifications were evaluated by CUSE. Apparent maximum elasticity (Emax) estimates resulting from individual macrocalcifications (with diameters of 2mm, 3mm, 5mm, 6mm, 9mm, 11mm, and 15mm) showed values over 50 kPa for all cases, which represents more than 100% increase over background (~21kPa). We considered a 2cm-diameter circular region of interest for all phantom experiments. Mean elasticity (Emean) values varied from 26 kPa to 73 kPa, depending on the macrocalcification size. Highly dense clusters of microcalcifications showed higher Emax values than clusters of microcalcification with low concentrations, but the difference in Emean values was not significant. Our results demonstrate that the presence of large isolated macrocalcifications and highly concentrated clusters of microcalcifications can introduce areas with apparent high elasticity in SWE. Considering that benign breast masses normally have significantly lower elasticity values than malignant tumors, such areas with high elasticity appearing due to presence of calcification in benign breast masses may lead to misdiagnosis.

Institutional Pedagogy and Semiosis: Investigating the Missing Link between Peirce's Semiotics and Effective Semiotics

ERIC Educational Resources Information Center

Pesce, Sebastien

2011-01-01

My aim in this paper is to show the relevance of an "effective semiotics"; that is, a field study based upon Peirce's semiotics. The general context of this investigation is educational semiotics rather than semiotics of teaching: I am concerned with a general approach of educational processes, not with skills and curricula. My paper is…

‘Leave Your Ego at the Door’: A Narrative Investigation into Effective Wingsuit Flying

PubMed Central

Arijs, Cedric; Chroni, Stiliani; Brymer, Eric; Carless, David

2017-01-01

In recent years there has been a rapid growth in interest in extreme sports. For the most part research has focused on understanding motivations for participation in extreme sports and very little research has attempted to investigate the psychological structure of effective performance. Those few studies that have attempted to explore this issue have tested models designed for traditional sport on adventure sports. However, extreme sports are not the same as adventure sports or traditional sports. This study employed a narrative approach to investigate experiences of effective performance in the extreme sport of proximity wingsuit flying. An overarching theme we labeled ‘leave your ego at the door,’ emerged based on four sub-themes: (1) know thy self, (2) know thy skills, (3) know the environment now, and (4) tame the ‘inner animal.’ These themes are presented and discussed in relation to performance and discovery narratives identified within elite sport, thereby shedding light on how participants’ experiences of the extreme sport of proximity wingsuit flying differ from dominant stories within traditional sports. PMID:29204131

SPH investigation of the thermal effects on the fluid mixing in a microchannel with rotating stirrers

NASA Astrophysics Data System (ADS)

Shamsoddini, Rahim

2018-04-01

An incompressible smoothed particle hydrodynamics algorithm is proposed to model and investigate the thermal effect on the mixing rate of an active micromixer in which the rotating stirrers enhance the mixing rate. In liquids, mass diffusion increases with increasing temperature, while viscosity decreases; so, the local Schmidt number decreases considerably with increasing temperature. The present study investigates the effect of wall temperature on mixing rate with an improved SPH method. The robust SPH method used in the present work is equipped with a shifting algorithm and renormalization tensors. By introducing this new algorithm, the several mass, momentum, energy, and concentration equations are solved. The results, discussed for different temperature ratios, show that mixing rate increases significantly with increased temperature ratio.

Spectral chemistry of green glass-bearing 15426 regolith

NASA Technical Reports Server (NTRS)

Burns, R. G.; Dyar, M. D.

1983-01-01

The detection of appreciable concentrations of ferric iron in a synthetic green glass equilibrated at an oxygen fugacity of 10 to the -11th atm prompted a Moessbauer spectral study of pristine emerald-green glass spherules carefully handpicked from regolith sample 15426. No Fe(3+) ions were detected in this lunar sample or in a synthetic green glass simulant equilibrated at fO2 = 10 to the -14th atm, suggesting that the green glass clods in rock 15426 formed under conditions of correspondingly low oxygen fugacities. The Moessbauer spectra indicated the presence of olivine crystallites in the lunar emerald green glass spherules. Measurements of homogeneous and partially devitrified synthetic silicate glasses revealed that significant changes of coordination environment about Fe(2+) ions in the glass structure occur during crystallization of olivine crystals from the melt.

An in vitro investigation of endocrine disrupting effects of the mycotoxin alternariol

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

Frizzell, Caroline; Ndossi, Doreen; Sokoine University of Agriculture, Morogoro

2013-08-15

Alternariol (AOH) is a mycotoxin commonly produced by Alternaria alternata on a wide range of foods. Few studies to date have been performed to evaluate the effects of AOH on endocrine activity. The present study makes use of in vitro mammalian cellular based assays and gene expression to investigate the ability of AOH to act as an endocrine disruptor by various modes of action. Reporter gene assays (RGAs), incorporating natural steroid hormone receptors for oestrogens, androgens, progestagens and glucocorticoids were used to identify endocrine disruption at the level of nuclear receptor transcriptional activity, and the H295R steroidogenesis assay was usedmore » to assess endocrine disruption at the level of gene expression and steroid hormone production. AOH exhibited a weak oestrogenic response when tested in the oestrogen responsive RGA and binding of progesterone to the progestagen receptor was shown to be synergistically increased in the presence of AOH. H295R cells when exposed to 0.1–1000 ng/ml AOH, did not cause a significant change in testosterone and cortisol hormones but exposure to 1000 ng/ml (3.87 μM) AOH resulted in a significant increase in estradiol and progesterone production. In the gene expression study following exposure to 1000 ng/ml (3.87 μM) AOH, only one gene NR0B1 was down-regulated, whereas expression of mRNA for CYP1A1, MC2R, HSD3B2, CYP17, CYP21, CYP11B2 and CYP19 was up-regulated. Expression of the other genes investigated did not change significantly. In conclusion AOH is a weak oestrogenic mycotoxin that also has the ability to interfere with the steroidogenesis pathway. - Highlights: • Alternariol was investigated for endocrine disrupting activity. • Reporter gene assays and the H295R steroidogenesis assay have been used. • An oestrogenic effect of alternariol was observed. • This can lead to an increase in expression of the progesterone receptor. • Alternariol is capable of modulating hormone production and gene

DFT investigations of the hydrogenation effect on silicene/graphene hybrids.

PubMed

Drissi, L B; Saidi, E H; Bousmina, M; Fassi-Fehri, O

2012-12-05

We report here a study on the effect of hydrogenation on a new one-atom thick material made of silicon and carbon atoms (silicene/graphene (SG) hybrid) within density functional theory. The structural, electronic and magnetic properties are investigated for non-, semi- and fully hydrogenated SG hybrids in a chair configuration and are compared with their parent materials. Calculations reveal that pure SG is a non-zero band gap semi-conductor with stable planar honeycomb structure. So mixing C and Si in an alternating manner gives another way to generate a finite band gap in one-atom thick materials. Fully hydrogenation makes the gap larger; however half chemical modification with H reduces the gap in favor of ferromagnetism order. The findings of this work open a wide spectrum of possibilities for designing SG-based nanodevices with controlled and tuned properties.

Investigating the effects of terahertz radiation on Bacillus subtilis

NASA Astrophysics Data System (ADS)

Giles, Jillian P.; Raitt, Brittany J.; Joseph, Cecil S.; Hines, Mark E.; Giles, Robert H.

2012-03-01

Medical and security sensing applications of Terahertz (THz) imaging are currently being developed. As a result, there is a need to further investigate the effects of THz radiation on biological systems. In this study, a 94 GHz mechanically tuned Gunn Oscillator was used to irradiate Bacillus subtilis at 94 GHz. The bacteria were cultured in trypticase soy broth (TSB) and placed in polystyrene 96 well plates. The samples where irradiated during the exponential growth phase for 1, 2, and 24 hours. Both the experimental and control plates were kept at room temperature (~25°C) and were monitored for the duration of the experiment using thermocouples interfaced with a computer via Labview software. By evaluating the absorption of each well at 600nm immediately before and after irradiation, the population density within each well was assessed. Following this, the metabolic activity of each well was measured after irradiation by adding tetrazolium dye, XTT, to the wells and evaluating the absorption of each well at 490nm after 2 hours of incubation.

Wind tunnel investigation of helicopter-rotor wake effects on three helicopter fuselage models

NASA Technical Reports Server (NTRS)

Wilson, J. C.; Mineck, R. E.

1975-01-01

The effects of rotor wake on helicopter fuselage aerodynamic characteristics were investigated in the Langley V/STOL tunnel. Force, moment, and pressure data were obtained on three fuselage models at various combinations of windspeed, sideslip angle, and pitch angle. The data show that the influence of rotor wake on the helicopter fuselage yawing moment imposes a significant additional thrust requirement on the tail rotor of a single-rotor helicopter at high sideslip angles.

Analytical investigation of the faster-is-slower effect with a simplified phenomenological model

NASA Astrophysics Data System (ADS)

Suzuno, K.; Tomoeda, A.; Ueyama, D.

2013-11-01

We investigate the mechanism of the phenomenon called the “faster-is-slower”effect in pedestrian flow studies analytically with a simplified phenomenological model. It is well known that the flow rate is maximized at a certain strength of the driving force in simulations using the social force model when we consider the discharge of self-driven particles through a bottleneck. In this study, we propose a phenomenological and analytical model based on a mechanics-based modeling to reveal the mechanism of the phenomenon. We show that our reduced system, with only a few degrees of freedom, still has similar properties to the original many-particle system and that the effect comes from the competition between the driving force and the nonlinear friction from the model. Moreover, we predict the parameter dependences on the effect from our model qualitatively, and they are confirmed numerically by using the social force model.

Investigating the effect of peptide agonists on the chondrogenic differentiation of human mesenchymal stem cells using design of experiments.

PubMed

Renner, Julie N; Liu, Julie C

2013-01-01

Human mesenchymal stem cells (MSCs) are attractive for use in cartilage tissue engineering. Cells are often seeded in a structural scaffold containing growth factors. Peptide mimics of full-length growth factors are a promising alternative because they are less expensive and easier to manufacture. We investigated four short peptides for their effect on the chondrogenesis of human MSCs. The peptides were originally designed to mimic bone morphogenetic protein-2 (BMP-2), transforming growth factor-beta 1 (TGF-β1), and insulin, all of which have been shown to affect MSC chondrogenesis. Previous studies demonstrated that the peptides elicited bioactivity in other cell types, but the peptides have not been investigated for their effect on chondrogenesis in human MSCs. In a preliminary investigation, peptides were added to a pellet culture of human MSCs and assayed for their effect on glycosaminoglycan (GAG) production. These experiments determined peptide concentrations used in a full-factorial experiment to investigate any interactions. The experiment revealed the BMP peptide as a robust stimulant for GAG production. . © 2013 American Institute of Chemical Engineers.

Investigating the effects of streamline-based fiber tractography on matrix scaling in brain connective network.

PubMed

Jan, Hengtai; Chao, Yi-Ping; Cho, Kuan-Hung; Kuo, Li-Wei

2013-01-01

Investigating the brain connective network using the modern graph theory has been widely applied in cognitive and clinical neuroscience research. In this study, we aimed to investigate the effects of streamline-based fiber tractography on the change of network properties and established a systematic framework to understand how an adequate network matrix scaling can be determined. The network properties, including degree, efficiency and betweenness centrality, show similar tendency in both left and right hemispheres. By employing the curve-fitting process with exponential law and measuring the residuals, the association between changes of network properties and threshold of track numbers is found and an adequate range of investigating the lateralization of brain network is suggested. The proposed approach can be further applied in clinical applications to improve the diagnostic sensitivity using network analysis with graph theory.

A Vodcasted, Cross-Disciplinary, Behavioral Neuroscience Laboratory Exercise Investigating the Effects of Methamphetamine on Aggression

ERIC Educational Resources Information Center

Shanks, Ryan A.; Southard, E. Megan; Tarnowski, Laura; Bruster, Matthew; Wingate, Stacia W.; Dalman, Nancy; Lloyd, Steven A.

2011-01-01

This article describes a laboratory experience utilizing videos to engage students in hypothesis-driven experimentation in behavioral neuroscience. It provides students with an opportunity to investigate the effects of chronic methamphetamine exposure on aggression in adult mice using a resident-intruder paradigm. Instructors and students only…

Investigating the Effects of Prompts on Argumentation Style, Consensus and Perceived Efficacy in Collaborative Learning

ERIC Educational Resources Information Center

Harney, Owen M.; Hogan, Michael J.; Broome, Benjamin; Hall, Tony; Ryan, Cormac

2015-01-01

This paper investigates the effects of task-level versus process-level prompts on levels of perceived and objective consensus, perceived efficacy, and argumentation style in the context of a computer-supported collaborative learning session using Interactive Management (IM), a computer facilitated thought and action mapping methodology. Four…

[Investigation of glucocorticoid-induced side effects in patients with autoimmune diseases].

PubMed

Nakajima, Aya; Doki, Kosuke; Homma, Masato; Sagae, Terumi; Saito, Reiko; Ito, Satoshi; Sumida, Takayuki; Kohda, Yukinao

2009-04-01

High dose glucocorticoids (GC) are commonly used for the treatment of autoimmune diseases. The frequencies, occurrence day and dose-dependency for side effects may be different among the events such as diabetes mellitus, hyperlipidemia, infectious disease, osteoporosis, and peptic ulcer. We investigated GC-induced side effects in 68 patients treated with GC for autoimmune diseases. Initial dose of GC (prednisolone equivalent) was 0.67+/-0.35 mg/kg/d. Hypercholesterolemia (66%), hypertension (62%), insomnia (50%), hypertriglyceridemia (44%), excessive appetite (38%), hyperglycemia (18%), digestive symptom (16%), moon-shaped face (13%) and oral candidiasis (12%) were observed in 63 patients treated with GC. Hypercholesterolemia, excessive appetite, digestive symptom, moon-shaped face, and oral candidiasis were associated with the initial dose of prednisolone greater than 0.80 mg/kg/d. Insomnia [median 6 days (range 1-88)], excessive appetite [7 days (2-57)], hypertension [8 days (1-37)], digestive symptom [15 days (1-87)] and hypercholesterolemia [19 days (3-77)] were observed early after 6-19 days starting GC. On the other hand, hypertriglyceridemia [33 days (2-131)], oral candidiasis [35 days (7-52)] and hyperglycemia [60 days (4-134)] were developed after 33-60 days starting GC. Since the frequencies, dose-dependency and occurrence day were different among the side effects of GC, medical staffs including physicians and pharmacists should pay attention such features of the events in the treatment of autoimmune diseases.

An investigation into field effects of consciousness from the perspectives of Maharishi's Vedic Science and physics

NASA Astrophysics Data System (ADS)

Kleinschnitz, Kurt Warren

1997-05-01

A long-range field effect of consciousness has been reported repeatedly in the scientific literature over the past twenty years. This phenomenon is called the Maharishi Effect, after Maharishi Mahesh Yogi, the first to predict it. The Maharishi Effect is the phenomenon of improved societal trends resulting from the practice of the Transcendental Meditationoler program or group practice of the TM-Sidhioler program by a small fraction of a population. The Maharishi Effect is fundamentally a phenomenon of radiation of evolutionary influence arising from the enlivenment of pure consciousness, the unified field of natural law, in the perspective of Maharishi's Vedic Science. This perspective is corroborated by forty-three published or presented papers reporting on results of Maharishi Effect interventions world-wide at city, national, international, and global scales. Present day standard- model physics and physiology do not account for the outcomes of the research on the Maharishi Effect. Because the observed societal impact of the Maharishi Effect influence must be based in an impact on the individual, and investigators report detection of the effect in individual physiological measurements, a simple robust indicator for the effect might aid physiologists and physicists in the effort to extend their sciences to include such field effects of consciousness. Thus, this dissertation reports on two experiments investigating simple, robust, objective indicators for the effect. The dissertation concludes on a practical note with a description of the promise, available through concerted utilization of the knowledge and technologies of consciousness in Maharishi's Vedic Science, for enhanced national and global security in the face of unprecedented nuclear, biological, and genetic threats for which the modern sciences offer few sensible solutions. ftnolerTranscendental Meditation and TM-Sidhi are service marks registered in the United States Patent and Trademark Office

Investigation of cost effective truck weight enforcement.

DOT National Transportation Integrated Search

2008-01-01

This research investigates the best way to enforce the truck size and weight limits and by doing : so decrease the damage that is being done to Oklahoma's roads and bridges. In the process a : survey of all state DOT's was conducted to help determine...

Is participation in research as an investigator an effective form of continuing medical education?

PubMed Central

Huas, D; Wallace, P

2000-01-01

Continuing medical education and research are a daily necessity for general practitioners (GPs). This study investigated the possibility that participation in research is an effective form of continuing medical education. Although there was an indication that some modification of GPs' knowledge and skills had occurred, it was not possible to conclude that this was entirely due to participation in research. PMID:11224971

Investigation of the Effects of Brain Teasers on Attention Spans of Pre-School Children

ERIC Educational Resources Information Center

Altun, Meryem; Hazar, Muhsin; Hazar, Zekihan

2016-01-01

The purpose of this study is to investigate the effects of brain teasers on attention spans of preschool children of age six. The study was conducted using an experimental design with a control group and pre-test/post-test. The sample of the study is children of age six selected via random appointment among ones who were enrolled in the Merkez…

Meta-analysis of the effectiveness of chronic care management for diabetes: investigating heterogeneity in outcomes.

PubMed

Elissen, Arianne M J; Steuten, Lotte M G; Lemmens, Lidwien C; Drewes, Hanneke W; Lemmens, Karin M M; Meeuwissen, Jolanda A C; Baan, Caroline A; Vrijhoef, Hubertus J M

2013-10-01

The study aims to support decision making on how best to redesign diabetes care by investigating three potential sources of heterogeneity in effectiveness across trials of diabetes care management. Medline, CINAHL and PsycInfo were searched for systematic reviews and empirical studies focusing on: (1) diabetes mellitus; (2) adult patients; and (3) interventions consisting of at least two components of the chronic care model (CCM). Systematic reviews were analysed descriptively; empirical studies were meta-analysed. Pooled effect measures were estimated using a meta-regression model that incorporated study quality, length of follow-up and number of intervention components as potential predictors of heterogeneity in effects. Overall, reviews (n = 15) of diabetes care programmes report modest improvements in glycaemic control. Empirical studies (n = 61) show wide-ranging results on HbA1c, systolic blood pressure and guideline adherence. Differences between studies in methodological quality cannot explain this heterogeneity in effects. Variety in length of follow-up can explain (part of) the variability, yet not across all outcomes. Diversity in the number of included intervention components can explain 8-12% of the heterogeneity in effects on HbA1c and systolic blood pressure. The outcomes of chronic care management for diabetes are generally positive, yet differ considerably across trials. The most promising results are attained in studies with limited follow-up (<1 year) and by programmes including more than two CCM components. These factors can, however, explain only part of the heterogeneity in effectiveness between studies. Other potential sources of heterogeneity should be investigated to ensure implementation of evidence-based improvements in diabetes care. © 2012 John Wiley & Sons Ltd.

The effect on toxicology, biochemistry and immunology investigations by the use of targeted post-mortem computed tomography angiography.

PubMed

Rutty, G N; Smith, P; Visser, T; Barber, J; Amorosa, J; Morgan, B

2013-02-10

It is recognised in autopsy practice that investigations such as toxicology can be affected by post-mortem change. Post-mortem computed tomography angiography (PMCT-A) involves the injection of contrast agents. This could cause dilution of a biological fluid sample or cause the circulation of blood after death by mechanical pumping, and thus has the potential to affect laboratory investigations. We undertook a small sample study to consider whether targeted PMCT-A had any significant effect on subsequent samples taken for biochemical, toxicological or immunological investigations. Although the results of our study do illustrate differences between the pre and post PMCT-A results, these differences are considered not to be of diagnostic significance and not due to the direct effect of targeted PMCT-A. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Effects of the 2017 Solar Eclipse on HF Radio Propagation and the D-Region Ionosphere: Citizen Science Investigation

NASA Technical Reports Server (NTRS)

Fry, C. D.; Rawlins, L.; Krause, L. H.; Suggs, R. M.; McTernan, J. K.; Adams, M. L.; Gallagher, D. L.; Anderson, Scott; Allsbrooks, Robert IV

2017-01-01

August 21, 2017 provided a unique opportunity to investigate the effects of the total solar eclipse on high frequency (HF) radio propagation and ionospheric variability. In Marshall Space Flight Center's partnership with the US Space and Rocket Center (USSRC) and Austin Peay State University (APSU), we engaged students and citizen scientists in an investigation of the eclipse effects on the mid-latitude ionosphere. Activities included implementing and configuring software, monitoring the HF Amateur Radio frequency bands and collecting radio transmission data on days before, the day of, and days after the eclipse to build a continuous record of changing propagation conditions as the moon's shadow marched across the United States. Post-eclipse radio propagation analysis provided insights into ionospheric variability due to the eclipse. We report on results, interpretation, and conclusions of these investigations.

Numerical and experimental investigation of light trapping effect of nanostructured diatom frustules

NASA Astrophysics Data System (ADS)

Chen, Xiangfan; Wang, Chen; Baker, Evan; Sun, Cheng

2015-07-01

Recent advances in nanophotonic light-trapping technologies offer promising solutions in developing high-efficiency thin-film solar cells. However, the cost-effective scalable manufacturing of those rationally designed nanophotonic structures remains a critical challenge. In contrast, diatoms, the most common type of phytoplankton found in nature, may offer a very attractive solution. Diatoms exhibit high solar energy harvesting efficiency due to their frustules (i.e., hard porous cell wall made of silica) possessing remarkable hierarchical micro-/nano-scaled features optimized for the photosynthetic process through millions of years of evolution. Here we report numerical and experimental studies to investigate the light-trapping characteristic of diatom frustule. Rigorous coupled wave analysis (RCWA) and finite-difference time-domain (FDTD) methods are employed to investigate the light-trapping characteristics of the diatom frustules. In simulation, placing the diatom frustules on the surface of the light-absorption materials is found to strongly enhance the optical absorption over the visible spectrum. The absorption spectra are also measured experimentally and the results are in good agreement with numerical simulations.

Investigation at Low Speeds of the Effect of Aspect Ratio and Sweep on Rolling Stability Derivatives of Untapered Wings

NASA Technical Reports Server (NTRS)

Goodman, Alex; Fisher, Lewis R

1950-01-01

A low-scale wind-tunnel investigation was conducted in rolling flow to determine the effects of aspect ratio and sweep (when varied independently) on the rolling stability derivatives for a series of untapered wings. The rolling-flow equipment of the Langley stability tunnel was used for the tests. The data of the investigation have been used to develop a method of accounting for the effects of the drag on the yawing moment due to rolling throughout the lift range.

Investigation of defect-induced abnormal body current in fin field-effect-transistors

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

Liu, Kuan-Ju; Tsai, Jyun-Yu; Lu, Ying-Hsin

2015-08-24

This letter investigates the mechanism of abnormal body current at the linear region in n-channel high-k/metal gate stack fin field effect transistors. Unlike body current, which is generated by impact ionization at high drain voltages, abnormal body current was found to increase with decreasing drain voltages. Notably, the unusual body leakage only occurs in three-dimensional structure devices. Based on measurements under different operation conditions, the abnormal body current can be attributed to fin surface defect-induced leakage current, and the mechanism is electron tunneling to the fin via the defects, resulting in holes left at the body terminal.

Experimental investigation of control/display augmentation effects in a compensatory tracking task

NASA Technical Reports Server (NTRS)

Garg, Sanjay; Schmidt, David K.

1988-01-01

The effects of control/display augmentation on human performance and workload have been investigated for closed-loop, continuous-tracking tasks by a real-time, man-in-the-loop simulation study. The experimental results obtained indicate that only limited improvement in actual tracking performance is obtainable through display augmentation alone; with a very high level of display augmentation, tracking error will actually deteriorate. Tracking performance improves when status information is furnished for reasonable levels of display quickening; again, very high quickening levels lead to tracking error deterioration due to the incompatibility between the status information and the quickened signal.

Investigation of the thermal hazardous effect of protective clothing caused by stored energy discharge.

PubMed

He, Jiazhen; Lu, Yehu; Chen, Yan; Li, Jun

2017-09-15

In addition to direct thermal energy from a heating source, a large amount of thermal energy stored in clothing will continuously discharge to skin after exposure. Investigating the thermal hazardous effect of clothing caused by stored energy discharge is crucial for the reliability of thermal protective clothing. In this study several indices were proposed and applied to evaluate the impact of thermal energy discharge on human skin. The heat discharge from different layers of fabric systems was investigated, and the influences of air gaps and applied compression were examined. Heat fluxes at the boundaries of fabric layers and the distribution of heat discharge were determined. Additionally, the correlation between heat storage during exposure and heat discharge after exposure was identified. The results demonstrated that heat discharge to the skin could be correlated with heat storage within the fabric, however, it highly depended on the air gap under clothing, the applied compression, and the insulation provided by the fabric layers. Results from this study could contribute to thoroughly understanding the thermal hazardous effect of clothing and enhance the technical basis for developing new fabric combinations to minimize energy discharge after exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

Investigation of the influence of the photodynamic effect on micro-organisms using the laser photothermal cytometry method

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

Lapotko, D O; Kuchinskii, G S; Zharov, V P

1999-12-31

An investigation of the influence of the photodynamic effect on S.aureus and E.coli bacteria in the presence of blood cells was made by the laser photothermal cytometry method. Elements of the theory of the photothermal method are considered for the case of pulsed lasers used in microscopy. Chlorin in doses of 0.02 mg litre{sup -1} was used as a photosensitiser. The results of the investigation made it possible to propose the possibility of an immunomodulation effect caused by introducing photoactivated chlorin into the cell - microbe system. It was found that the photothermal parameters of the cells interacting with microbesmore » in the presence of photoactivated chlorin differed from the parameters of intact cells much less than in the absence of chlorin. However, a more pronounced bactericidal effect was observed in the samples treated with chlorin. (lasers in medicine)« less

Large object investigation by digital holography with effective spectrum multiplexing under single-exposure approach

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

Liu, Ning, E-mail: coolboy006@sohu.com; Zhang, Yingying; Xie, Jun

2014-10-13

We present a method to investigate large object by digital holography with effective spectrum multiplexing under single-exposure approach. This method splits the original reference beam and redirects one of its branches as a second object beam. Through the modified Mach-Zehnder interferometer, the two object beams can illuminate different parts of the large object and create a spectrum multiplexed hologram onto the focal plane array of the charge-coupled device/complementary metal oxide semiconductor camera. After correct spectrum extraction and image reconstruction, the large object can be fully observed within only one single snap-shot. The flexibility and great performance make our method amore » very attractive and promising technique for large object investigation under common 632.8 nm illumination.« less

Investigating the Effectiveness of Classroom Diagnostic Tools

ERIC Educational Resources Information Center

Schultz, Robert K.

2012-01-01

The primary purposes of the study are to investigate what teachers experience while using the Classroom Diagnostic Tools (CDT) and to relate those experiences to the rate of growth in students' mathematics achievement. The CDT contains three components: an online computer adaptive diagnostic test, interactive web-based student reports, and…

Two Years of Chemical Sampling on Meridiani Planum by the Alpha Particle X-Ray Spectrometer Onboard the Mars Exploration Rover Opportunity

NASA Technical Reports Server (NTRS)

Bruckner, J.; Gellert, R.; Clark, B.C.; Dreibus, G.; Rieder, R.; Wanke, H.; d'Uston, C.; Economou, T.; Klingelhofer, G.; Lugmair, G.;

Investigation of Maternal Genotype Effects in Autism by Genome-Wide Association

PubMed Central

Yuan, Han; Dougherty, Joseph D.

2014-01-01

Lay Abstract Autism spectrum disorders (ASDs) are pervasive developmental disorders which have both a genetic and environmental component. One source of the environmental component is the in utero (prenatal) environment. The maternal genome can potentially contribute to the risk of autism in children by altering this prenatal environment. In this study, the possibility of maternal genotype effects was explored by looking for common variants (single nucleotide polymorphisms, or SNPs) in the maternal genome associated with increased risk of autism in children. We performed a case/control genome-wide association study (GWAS) using mothers of probands as cases and either fathers of probands or normal females as controls, using two collections of families with autism. We did not identify any SNP that reached significance and thus a common variant of large effect is unlikely. However, there was evidence for the possibility of a large number of alleles each carrying a small effect. This suggested that if there is a contribution to autism risk through common-variant maternal genetic effects, it may be the result of multiple loci of small effects. We did not investigate rare variants in this study. Scientific Abstract Like most psychiatric disorders, autism spectrum disorders have both a genetic and an environmental component. While previous studies have clearly demonstrated the contribution of in utero (prenatal) environment on autism risk, most of them focused on transient environmental factors. Based on a recent sibling study, we hypothesized that environmental factors could also come from the maternal genome, which would result in persistent effects across siblings. In this study, the possibility of maternal genotype effects was examined by looking for common variants (single nucleotide polymorphisms, or SNPs) in the maternal genome associated with increased risk of autism in children. A case/control genome-wide association study (GWAS) was performed using mothers of

Cluster dynamics modeling and experimental investigation of the effect of injected interstitials

NASA Astrophysics Data System (ADS)

Michaut, B.; Jourdan, T.; Malaplate, J.; Renault-Laborne, A.; Sefta, F.; Décamps, B.

2017-12-01

The effect of injected interstitials on loop and cavity microstructures is investigated experimentally and numerically for 304L austenitic stainless steel irradiated at 450 °C with 10 MeV Fe5+ ions up to about 100 dpa. A cluster dynamics model is parametrized on experimental results obtained by transmission electron microscopy (TEM) in a region where injected interstitials can be safely neglected. It is then used to model the damage profile and study the impact of self-ion injection. Results are compared to TEM observations on cross-sections of specimens. It is shown that injected interstitials have a significant effect on cavity density and mean size, even in the sink-dominated regime. To quantitatively match the experimental data in the self-ions injected area, a variation of some parameters is necessary. We propose that the fraction of freely migrating species may vary as a function of depth. Finally, we show that simple rate theory considerations do not seem to be valid for these experimental conditions.

Experimental investigation of jet-induced loads on a flat plate in hover out-of-ground effect

NASA Technical Reports Server (NTRS)

Kuhlman, J. M.; Warcup, R. W.

1979-01-01

Effects of varying jet decay rate on jet-induced loads on a flat plate located in the plane of the jet exit perpendicular to the jet axis were investigated using a small-scale laboratory facility. Jet decay rate has been varied through use of two cylindrical centerbodies having either a flat or hemispherical tip, which were submerged various distances below the flat plate jet exit plane. Increased jet decay rate, caused by the presence of a center-body or plug in the jet nozzle, led to an increased jet-induced lift loss on the flat plate. Jet-induced lift losses reached 1 percent of the jet thrust for the quickest jet decay rates for plate areas equal to 100 times the effective jet exit area. The observed lift loss versus jet decay rate trend agreed well with results of previous investigations.

Porosimetry as an effective method of fuel cell investigation

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

Kazarinov, V.E.

1996-04-01

A porosimetric method is described for the investigation of all kinds of porous materials including soft or frail materials and powders. The method is well suited for the investigation of electrodes in fuel cells and batteries. The method is nondestructive and allows for repeated measurements on the same sample.

Hemodynamic effect of bypass geometry on intracranial aneurysm: A numerical investigation.

PubMed

Kurşun, Burak; Uğur, Levent; Keskin, Gökhan

2018-05-01

Hemodynamic analyzes are used in the clinical investigation and treatment of cardiovascular diseases. In the present study, the effect of bypass geometry on intracranial aneurysm hemodynamics was investigated numerically. Pressure, wall shear stress (WSS) and velocity distribution causing the aneurysm to grow and rupture were investigated and the best conditions were tried to be determined in case of bypassing between basilar (BA) and left/right posterior arteries (LPCA/RPCA) for different values of parameters. The finite volume method was used for numerical solutions and calculations were performed with the ANSYS-Fluent software. The SIMPLE algorithm was used to solve the discretized conservation equations. Second Order Upwind method was preferred for finding intermediate point values in the computational domain. As the blood flow velocity changes with time, the blood viscosity value also changes. For this reason, the Carreu model was used in determining the viscosity depending on the velocity. Numerical study results showed that when bypassed, pressure and wall shear stresses reduced in the range of 40-70% in the aneurysm. Numerical results obtained are presented in graphs including the variation of pressure, wall shear stress and velocity streamlines in the aneurysm. Considering the numerical results for all parameter values, it is seen that the most important factors affecting the pressure and WSS values in bypassing are the bypass position on the basilar artery (L b ) and the diameter of the bypass vessel (d). Pressure and wall shear stress reduced in the range of 40-70% in the aneurysm in the case of bypass for all parameters. This demonstrates that pressure and WSS values can be greatly reduced in aneurysm treatment by bypassing in cases where clipping or coil embolization methods can not be applied. Copyright © 2018 Elsevier B.V. All rights reserved.

Numerical investigations of passive scalar transport in Taylor-Couette flows: Counter-rotation effect

NASA Astrophysics Data System (ADS)

Ouazib, Nabila; Salhi, Yacine; Si-Ahmed, El-Khider; Legrand, Jack; Degrez, G.

2017-07-01

Numerical methods for solving convection-diffusion-reaction (CDR) scalar transport equation in three-dimensional flow are used in the present investigation. The flow is confined between two concentric cylinders both the inner cylinder and the outer one are allowed to rotate. Direct numerical simulations (DNS) have been achieved to study the effects of the gravitational and the centrifugal potentials on the stability of incompressible Taylor-Couette flow. The Navier-Stokes equations and the uncoupled convection-diffusion-reaction equation are solved using a spectral development in one direction combined together with a finite element discretization in the two remaining directions. The complexity of the patterns is highlighted. Since, it increases as the rotation rates of the cylinders increase. In addition, the effect of the counter-rotation of the cylinders on the mass transfer is pointed out.

Investigation of Short Channel Effects on Device Performance for 60nm NMOS Transistor

NASA Astrophysics Data System (ADS)

Chinnappan, U.; Sanudin, R.

2017-08-01

In the aggressively scaled complementary metal oxide semiconductor (CMOS) devices, shallower p-n junctions and low sheet resistances are essential for short-channel effect (SCE) control and high device performance. The SCE are attributed to two physical phenomena that are the limitation imposed on electron drift characteristics in channel and the modification of the threshold voltage (Vth) due to the shortening channel length. The decrement of Vth with decrement in gate length is a well-known attribute in SCE known as “threshold voltage roll-off’. In this research, the Technology Computer Aided Design (TCAD) was used to model the SCE phenomenon effect on 60nm n-type metal oxide semiconductor (NMOS) transistor. There are three parameters being investigated, which are the oxide thickness (Tox), gate length (L), acceptor concentration (Na). The simulation data were used to visualise the effect of SCE on the 60nm NMOS transistor. Simulation data suggest that all three parameters have significant effect on Vth, and hence on the transistor performance. It is concluded that there is a trade-off among these three parameters to obtain an optimized transistor performance.

Updated CCPS Investigation Guidelines book.

PubMed

Philley, J; Pearson, K; Sepeda, A

2003-11-14

Incident investigation standards and performance criteria continue to improve. In recognition, the Center for Chemical Process Safety (CCPS) undertook a major project to upgrade and update the Incident Investigation Guidelines originally published in 1992. These significantly expanded guidelines provide a practical resource for effective investigation of process-related incidents, and reflect changes in good practices and expectations of regulators. This paper highlights the content of the new guidelines with special emphasis on what is new and improved. Entirely new chapters address the topics of legal considerations, the near-miss event, and continuous improvement of the investigation system. The objective of the guidelines is to allow chemical process organizations to develop and implement an incident investigation management system that is effective in identifying underlying causes.

Radiation and temperature effects on electronic components investigated under the CSTI high capacity power project

NASA Technical Reports Server (NTRS)

Schwarze, Gene E.; Niedra, Janis M.; Frasca, Albert J.; Wieserman, William R.

1993-01-01

The effects of nuclear radiation and high temperature environments must be fully known and understood for the electronic components and materials used in both the Power Conditioning and Control subsystem and the reactor Instrumentation and Control subsystem of future high capacity nuclear space power systems. This knowledge is required by the designer of these subsystems in order to develop highly reliable, long-life power systems for future NASA missions. A review and summary of the experimental results obtained for the electronic components and materials investigated under the power management element of the Civilian Space Technology Initiative (CSTI) high capacity power project are presented: (1) neutron, gamma ray, and temperature effects on power semiconductor switches, (2) temperature and frequency effects on soft magnetic materials; and (3) temperature effects on rare earth permanent magnets.

The Investigation of the Effects of Authentic Assessment Approach on Prospective Teachers' Problem-Solving Skills

ERIC Educational Resources Information Center

Kinay, Ismail; Bagçeci, Birsen

2016-01-01

The purpose of this study was to investigate the effect of authentic assessment, an approach used in Scientific Research Methods, on problem solving skills of prospective classroom teachers. The participant groups of the study consisted of sophomore prospective teachers who study at Dicle University in the Ziya Gökalp Education Faculty Classroom…

Effect of temperature on Acoustic Evaluation of standing trees and logs: Part 2: Field Investigation

Treesearch

Shan Gao; Xiping Wang; Lihai Wang; R. Bruce Allison

2013-01-01

The objectives of this study were to investigate the effect of seasonal temperature changes on acoustic velocity measured on standing trees and green logs and to develop models for compensating temperature differences because acoustic measurements are performed in different climates and seasons. Field testing was conducted on 20 red pine (Pinus resinosa...

Investigation of Micro-Scale Architectural Effects on Damage of Composites

NASA Technical Reports Server (NTRS)

Stier, Bertram; Bednarcyk, Brett A.; Simon, Jaan W.; Reese, Stefanie

2015-01-01

This paper presents a three-dimensional, energy based, anisotropic, stiffness reduction, progressive damage model for composite materials and composite material constituents. The model has been implemented as a user-defined constitutive model within the Abaqus finite element software package and applied to simulate the nonlinear behavior of a damaging epoxy matrix within a unidirectional composite material. Three different composite microstructures were considered as finite element repeating unit cells, with appropriate periodicity conditions applied at the boundaries. Results representing predicted transverse tensile, longitudinal shear, and transverse shear stress-strain curves are presented, along with plots of the local fields indicating the damage progression within the microstructure. It is demonstrated that the damage model functions appropriately at the matrix scale, enabling localization of the damage to simulate failure of the composite material. The influence of the repeating unit cell geometry and the effect of the directionality of the applied loading are investigated and discussed.

Investigating the Effect of Voltage-Switching on Low-Energy Task Scheduling in Hard Real-Time Systems

DTIC Science & Technology

2005-01-01

We investigate the effect of voltage-switching on task execution times and energy consumption for dual-speed hard real - time systems , and present a...scheduling algorithm and apply it to two real-life task sets. Our results show that energy can be conserved in embedded real - time systems using energy...aware task scheduling. We also show that switching times have a significant effect on the energy consumed in hard real - time systems .

Investigating Effects of Monsoon Winds on Hydrodynamics in the South China Sea

NASA Astrophysics Data System (ADS)

Chua, V. P.

2013-12-01

The South China Sea is a large marginal sea surrounded by land masses and island chains, and characterized by complex bathymetry and irregular coastlines. The circulation in South China Sea is subjected to seasonal and inter-annual variations of tidal and meteorological conditions. The effects of monsoon winds on hydrodynamics is investigated by applying spectral and harmonic analysis on surface elevation and wind data at stations located in the South China Sea. The analysis indicates varying responses to the seasonal monsoon depending on the location of the station. At Kaohsiung (located in northern South China Sea off Taiwan coast), tides from the Pacific Ocean and the southwest monsoon winds are found to be dominant mechanisms. The Kota Kinabalu and Bintulu stations, located to the east of South China Sea off Borneo coast, are influenced by low energy complex winds, and the shallow bottom bathymetry at these locations leads to tidal energy damping compared to other stations. The tidal dynamics at Tioman, located in southern South China Sea off Malaysia coast, are most responsive to the effects of the northeast monsoon. The complexity of our problem together with the limited amount of available data in the region presents a challenging research topic. An unstructured-grid SUNTANS model is employed to perform three-dimensional simulations of the circulation in South China Sea. Skill assessment of the model is performed by comparing model predictions of the surface elevations and currents with observations. The results suggest that the quality of the model prediction is highly dependent on horizontal grid resolution and coastline accuracy. The model may be used in future applications to investigate seasonal and inter-annual variations in hydrodynamics.

Further Investigation of the Support System Effects and Wing Twist on the NASA Common Research Model

NASA Technical Reports Server (NTRS)

Rivers, Melissa B.; Hunter, Craig A.; Campbell, Richard L.

2012-01-01

An experimental investigation of the NASA Common Research Model was conducted in the NASA Langley National Transonic Facility and NASA Ames 11-foot Transonic Wind Tunnel Facility for use in the Drag Prediction Workshop. As data from the experimental investigations was collected, a large difference in moment values was seen between the experiment and computational data from the 4th Drag Prediction Workshop. This difference led to a computational assessment to investigate model support system interference effects on the Common Research Model. The results from this investigation showed that the addition of the support system to the computational cases did increase the pitching moment so that it more closely matched the experimental results, but there was still a large discrepancy in pitching moment. This large discrepancy led to an investigation into the shape of the as-built model, which in turn led to a change in the computational grids and re-running of all the previous support system cases. The results of these cases are the focus of this paper.

Investigating Effects of Fused-Deposition Modeling (FDM) Processing Parameters on Flexural Properties of ULTEM 9085 using Designed Experiment.

PubMed

Gebisa, Aboma Wagari; Lemu, Hirpa G

2018-03-27

Fused-deposition modeling (FDM), one of the additive manufacturing (AM) technologies, is an advanced digital manufacturing technique that produces parts by heating, extruding and depositing filaments of thermoplastic polymers. The properties of FDM-produced parts apparently depend on the processing parameters. These processing parameters have conflicting advantages that need to be investigated. This article focuses on an investigation into the effect of these parameters on the flexural properties of FDM-produced parts. The investigation is carried out on high-performance ULTEM 9085 material, as this material is relatively new and has potential application in the aerospace, military and automotive industries. Five parameters: air gap, raster width, raster angle, contour number, and contour width, with a full factorial design of the experiment, are considered for the investigation. From the investigation, it is revealed that raster angle and raster width have the greatest effect on the flexural properties of the material. The optimal levels of the process parameters achieved are: air gap of 0.000 mm, raster width of 0.7814 mm, raster angle of 0°, contour number of 5, and contour width of 0.7814 mm, leading to a flexural strength of 127 MPa, a flexural modulus of 2400 MPa, and 0.081 flexural strain.

Investigating Effects of Fused-Deposition Modeling (FDM) Processing Parameters on Flexural Properties of ULTEM 9085 using Designed Experiment

PubMed Central

Gebisa, Aboma Wagari

2018-01-01

Fused-deposition modeling (FDM), one of the additive manufacturing (AM) technologies, is an advanced digital manufacturing technique that produces parts by heating, extruding and depositing filaments of thermoplastic polymers. The properties of FDM-produced parts apparently depend on the processing parameters. These processing parameters have conflicting advantages that need to be investigated. This article focuses on an investigation into the effect of these parameters on the flexural properties of FDM-produced parts. The investigation is carried out on high-performance ULTEM 9085 material, as this material is relatively new and has potential application in the aerospace, military and automotive industries. Five parameters: air gap, raster width, raster angle, contour number, and contour width, with a full factorial design of the experiment, are considered for the investigation. From the investigation, it is revealed that raster angle and raster width have the greatest effect on the flexural properties of the material. The optimal levels of the process parameters achieved are: air gap of 0.000 mm, raster width of 0.7814 mm, raster angle of 0°, contour number of 5, and contour width of 0.7814 mm, leading to a flexural strength of 127 MPa, a flexural modulus of 2400 MPa, and 0.081 flexural strain. PMID:29584674

Numerical investigation of the effect of sphere dimples on the drag crisis and the Magnus effect

NASA Astrophysics Data System (ADS)

Li, Jing; Tsubokura, Makoto; Tsunoda, Masaya

2015-11-01

The present study investigates the flow over a golf ball and a smooth sphere around the critical Reynolds numbers under both stationary and self-spinning conditions by conducting Large-eddy simulations (LES) based on high resolution unstructured grids. For the stationary cases, the present calculation results validate the promotion of the drag crisis at a relatively lower Reynolds number due to the golf ball dimples. It also shows that the golf ball dimples have a limited effect on the time-dependent lateral force development in the subcritical regime, whereas the dimples are beneficial in suppressing the lateral force oscillations in the supercritical regimes. With spin parameter Γ = 0.1, the drag coefficients for the spinning smooth sphere increase slightly in all Reynolds number regimes when compared to the stationary cases, whereas for the spinning golf ball, the drag force decreases in the critical regime and increases in the supercritical regime. For both spinning models, the inverse Magnus effect was reproduced in the critical regime, whereas in the supercritical regime the ordinary Magnus force was generated. Relatively weaker lift forces were also observed in the cases of the spinning golf balls when compared to the spinning smooth spheres.

Modification of local order in FePd films by low energy He{sup +} irradiation

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

Merkel, D. G.; Tancziko, F.; Sajti, Sz.

2008-07-01

Owing to their strong perpendicular magnetic anisotropy, FePd, CoPd, and their Co(Fe)Pt counterparts are candidate materials for ultrahigh density magnetic recording. The stability and magnetic properties of such films are largely dependent on the orientation and local distribution of the L1{sub 0} FePd phase fraction. Therefore, the formation and transformation of the L1{sub 0} phase in such thin films have been the subject of continued interest. Highly ordered epitaxial FePd(001) thin films (with an L1{sub 0} phase fraction of 0.81) were prepared by molecular-beam epitaxy on a MgO(001) substrate. The effect of postgrown room temperature, 130 keV He{sup +} irradiationmore » was investigated at fluences up to 14.9x10{sup 15} ions/cm{sup 2}. X-ray diffraction and conversion electron Moessbauer spectroscopy revealed that with increasing fluence, the L1{sub 0} FePd phase decomposes into the face centered cubic phase with random Fe and Pd occupation of the sites. A partially ordered local environment exhibiting a large hyperfine magnetic field also develops. Upon He{sup +} irradiation, the lattice parameter c of the FePd L1{sub 0} structure increases and the long range order parameter S steeply decreases. The Fe-Fe nearest-neighbor coordination in the Fe-containing environments increases on average from Fe{sub 47}Pd{sub 53} to Fe{sub 54}Pd{sub 46}, indicating a tendency of formation iron-rich clusters. The equilibrium parameters corresponding to the equiatomic L1{sub 0} phase were found at different fluences by conversion electron Moessbauer spectroscopy and by x-ray diffraction a difference, from which a plane-perpendicular compressive stress and a corresponding in-plane tensile stress are conjectured. The steep increase in the interface roughness above 7.4x10{sup 15} ions/cm{sup 2} is interpreted as a percolation-type behavior related to the high diffusion anisotropy in the L1{sub 0} phase.« less

Investigating the Effectiveness of an Educational Card Game for Learning How Human Immunology Is Regulated

ERIC Educational Resources Information Center

Su, TzuFen; Cheng, Meng-Tzu; Lin, Shu-Hua

2014-01-01

This study was conducted in an attempt to investigate the effectiveness of an educational card game we developed for learning human immunology. Two semesters of evaluation were included to examine the impact of the game on students' understanding and perceptions of the game-based instruction. Ninety-nine senior high school students (11th graders)…

Investigations of the inhibitory effects of tocopherol (vitamin E) on free radical deterioration of cellular membranes

NASA Technical Reports Server (NTRS)

Richardson, D.

1975-01-01

The inhibitory effects are investigated of d,1-alpha-tocopherol and d,1-alpha-tocopheryl acetate on the free radical deterioration of cellular membranes. The level of toxicity of d,1-alpha-tocopherol and d,1-alpha-tocopheryl acetate in mice is determined.

An investigation into the effectiveness of problem-based learning in a physical chemistry laboratory course

NASA Astrophysics Data System (ADS)

Gürses, Ahmet; Açıkyıldız, Metin; Doğar, Çetin; Sözbilir, Mustafa

2007-04-01

The aim of this study was to investigate the effectiveness of a problem-based learning (PBL) approach in a physical chemistry laboratory course. The parameters investigated were students’ attitudes towards a chemistry laboratory course, scientific process skills of students and their academic achievement. The design of the study was one group pre-test post-test. Four experiments, covering the topics adsorption, viscosity, surface tension and conductivity were performed using a PBL approach in the fall semester of the 2003/04 academic year at Kazim Karabekir Education Faculty of Atatürk University. Each experiment was done over a three week period. A total of 40 students, 18 male and 22 female, participated in the study. Students took the Physical Chemistry Laboratory Concept Test (PCLCT), Attitudes towards Chemistry Laboratory (ATCL) questionnaire and Science Process Skills Test (SPST) as pre and post-tests. In addition, the effectiveness of the PBL approach was also determined through four different scales; Scales Specific to Students’ Views of PBL. A statistically significant difference between the students’ academic achievement and scientific process skills at p

Effect of some metal chlorides on the transformation of pyrite to pyrrhotite

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

Shiley, R.H.; Konopka, K.L.; Hinckley, C.C.

1982-08-01

Samples of the iron-sulfide mineral pyrrhotite were prepared using a procedure designed to closely model the pyrite-to-pyrrhotite conversion that occurs during coal-conversion processing. Pyrite mixed with graphite converts to mixtures of monoclinic and hexagonal pyrrhotite when heated at 500C for 4.5 hours, and an iron-rich pyrrhotite (Fe10S11) forms at 600 to 700C. In addition to temperature effects, the pyrrhotites formed from pyrite in graphite are also dependent on additives or impurities in the form of metal salts. The pyrrhotites used in this study were prepared in the presence of selected transition metal chlorides: PdCl2, NiCl2, CoCl2, ZnCl2, MoCl5, and ZrCl4.more » When these metal salts were used, pyrrhotites with an increased number of iron vacancies were produced. For example, in the presence of ZrCl4 at temperatures as high as 700C, a pyrrhotite was produced that exhibited Moessbauer magnetic-splitting values characteristic of pyrrhotite with a high number of iron vacancies (iron-poor). These pyrrhotites were then converted to troilite at 400C in the presence of CO and H2; and this troilite is an active catalyst for the Fischer-Tropsch synthesis, alkene hydrogenation, the Boudouard reaction, the water-gas shift reaction, and the hydrodesulfurization of organic sulfur compounds.« less

In vivo investigation of temporal effects and drug delivery induced by transdermal microneedles with optical coherence tomography

PubMed Central

Tsai, Meng-Tsan; Lee, I-Chi; Lee, Zhung-Fu; Liu, Hao-Li; Wang, Chun-Chieh; Choia, Yo-Chun; Chou, Hsin-Yi; Lee, Jiann-Der

2016-01-01

Transdermal drug-delivery systems (TDDS) have been a growing field in drug delivery because of their advantages over parenteral and oral administration. Recent studies illustrate that microneedles (MNs) can effectively penetrate through the stratum corneum barrier to facilitate drug delivery. However, the temporal effects on skin and drug diffusion are difficult to investigate in vivo. In this study, we used optical coherence tomography (OCT) to observe the process by which MNs dissolve and to investigate the temporal effects on mouse skin induced by MNs, including the morphological and vascular changes. Moreover, the recovery process of the skin was observed with OCT. Additionally, we proposed a method to observe drug delivery by estimation of cross-correlation relationship between sequential 2D OCT images obtained at the same location, reflecting the variation in the backscattered intensity due to the diffusion of the rhodamine molecules encapsulated in MNs. Our observations supported the hypothesis that the temporal effects on skin due to MNs, the dissolution of MNs, and the drug diffusion process can be quantitatively evaluated with OCT. The results showed that OCT can be a potential tool for in vivo monitoring of effects and outcomes when MNs are used as a TDDS. PMID:27231627

Experimental investigation of heat transfer and effectiveness in corrugated plate heat exchangers having different chevron angles

NASA Astrophysics Data System (ADS)

Kılıç, Bayram; İpek, Osman

2017-02-01

In this study, heat transfer rate and effectiveness of corrugated plate heat exchangers having different chevron angles were investigated experimentally. Chevron angles of plate heat exchangers are β = 30° and β = 60°. For this purpose, experimentally heating system used plate heat exchanger was designed and constructed. Thermodynamic analysis of corrugated plate heat exchangers having different chevron angles were carried out. The heat transfer rate and effectiveness values are calculated. The experimental results are shown that heat transfer rate and effectiveness values for β = 60° is higher than that of the other. Obtained experimental results were graphically presented.

The effect of federal and state off-label marketing investigations on drug prescribing: The case of olanzapine.

PubMed

Wang, Bo; Studdert, David M; Sarpatwari, Ameet; Franklin, Jessica M; Landon, Joan; Kesselheim, Aaron S

2017-01-01

In the past decade, the federal government has frequently investigated and prosecuted pharmaceutical manufacturers for illegal promotion of drugs for indications not approved by the Food and Drug Administration (FDA) ("off-label" uses). State governments can choose to coordinate with the federal investigation, or pursue their own independent state investigations. One of the largest-ever off-label prosecutions relates to the atypical antipsychotic drug olanzapine (Zyprexa). In a series of settlements between 2008 and 2010, Eli Lilly paid $1.4 billion to the federal government and over $290 million to state governments. We examined the effect of these settlements on off-label prescribing of this medication, taking advantage of geographical differences in states' involvement in the investigations and the timing of the settlements. However, we did not find a reduction in off-label prescribing; rather, there were no prescribing changes among states that joined the federal investigation, those that pursued independent state investigations, and states that pursued no investigations at all. Since the settlements of state investigations of off-label prescribing do not appear to significantly impact prescribing rates, policymakers should consider alternate ways of reducing the prevalence of non-evidence-based off-label use to complement their ongoing investigations.

A preliminary investigation of the effects of the unified protocol on temperament.

PubMed

Carl, Jenna R; Gallagher, Matthew W; Sauer-Zavala, Shannon E; Bentley, Kate H; Barlow, David H

2014-08-01

Previous research has shown that two dimensions of temperament referred to as neuroticism/behavioral inhibition (N/BI) and extraversion/behavioral activation (E/BA) are key risk factors in the development and maintenance of anxiety and mood disorders (Brown & Barlow, 2009). Given such findings, these temperamental dimensions may represent promising treatment targets for individuals with emotional disorders; however, to date, few studies have investigated the effects of psychological treatments on temperamental constructs generally assumed to be "stable, inflexible, and pervasive" (American Psychiatric Association, 2000). The present study addresses this gap in the literature by examining the effects of the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders (UP; Barlow et al., 2011), a cognitive-behavioral therapy designed to target core processes of N/BI and E/BA temperaments, in a sample of adults with principal anxiety disorders and a range of comorbid conditions. Results revealed small effects of the UP on N/BI and E/BA compared with a waitlist control group at post-treatment. Additionally, decreases in N/BI and increases in E/BA during treatment were associated with improvements in symptoms, functioning, and quality of life. Findings provide preliminary support for the notion that the UP treatment facilitates beneficial changes in dimensions of temperament. Copyright © 2014 Elsevier Inc. All rights reserved.

Investigation of the inverse piezoelectric effect of trabecular bone on a micrometer length scale using synchrotron radiation.

PubMed

Wieland, D C F; Krywka, C; Mick, E; Willumeit-Römer, R; Bader, R; Kluess, D

2015-10-01

In the present paper we have investigated the impact of electro stimulation on microstructural parameters of the major constituents of bone, hydroxyapatite and collagen. Therapeutic approaches exhibit an improved healing rate under electric fields. However, the underlying mechanism is not fully understood so far. In this context one possible effect which could be responsible is the inverse piezo electric effect at bone structures. Therefore, we have carried out scanning X-ray microdiffraction experiments, i.e. we recorded X-ray diffraction data with micrometer resolution using synchrotron radiation from trabecular bone samples in order to investigate how the bone matrix reacts to an applied electric field. Different samples were investigated, where the orientation of the collagen matrix differed with respect to the applied electric field. Our experiments aimed to determine whether the inverse piezo electric effect could have a significant impact on the improved bone regeneration owing to electrostimulative therapy. Our data suggest that strain is in fact induced in bone by the collagen matrix via the inverse piezo electric effect which occurs in the presence of an adequately oriented electric field. The magnitude of the underlying strain is in a range where bone cells are able to detect it. In our study we report on the piezoelectric effect in bone which was already discovered and explored on a macro scale in the 1950. Clinical approaches utilize successfully electro stimulation to enhance bone healing but the exact mechanisms taking place are still a matter of debate. We have measured the stress distribution with micron resolution in trabecular bone to determine the piezo electric induced stress. Our results show that the magnitude of the induced stress is big enough to be sensed by cells and therefore, could be a trigger for bone remodeling and growth. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

The Effect of Lake Erie on Climate, Student Guide and Teacher Guide. OEAGLS Investigation 2.

ERIC Educational Resources Information Center

Meinke, James D.; Kennedy, Beth A.

This guidebook for teachers is accompanied by a student workbook. The investigations are intended to offer students an opportunity to study the effects of air temperature on air density and movement, the circulation of air and how it changes the amount of precipitation in the area around the Great Lakes, and the implications of the "lake…

Investigation of Reflective Teaching Practice Effect on Training Development Skills of the Pre-Service Teachers

ERIC Educational Resources Information Center

Töman, Ufuk

2017-01-01

This study aims to investigate the effect of the reflective teaching practice on the development of teaching skills of the pre-service teachers. This study is designed in the form of action research due to the nature of the case examined. The participants were 32 pre-service teachers at Bayburt University Faculty of Education Department of…

Investigating the effect of multiple layers of insulation with a bubble wrap experiment

NASA Astrophysics Data System (ADS)

Eggers, Dolores; Ruiz, Michael J.

2018-03-01

We provide a fun, inexpensive laboratory experiment for students to investigate the effects of multiple layers of insulation and observe diminishing values for additional layers using bubble wrap. This experiment provides an opportunity for students to learn about heat transfer through conduction using readily available materials. A water-ice pack is placed on top of five layers of bubble wrap. The temperature is taken between each layer periodically for at least 15 min. Students determine asymptotic temperatures for varying layers. This experiment also suggests a real world application.

Investigation of effect of solenoid magnet on emittances of ion beam from laser ablation plasma

NASA Astrophysics Data System (ADS)

Ikeda, Shunsuke; Romanelli, Mark; Cinquegrani, David; Sekine, Megumi; Kumaki, Masafumi; Fuwa, Yasuhiro; Kanesue, Takeshi; Okamura, Masahiro; Horioka, Kazuhiko

2014-02-01

A magnetic field can increase an ion current of a laser ablation plasma and is expected to control the change of the plasma ion current. However, the magnetic field can also make some fluctuations of the plasma and the effect on the beam emittance and the emission surface is not clear. To investigate the effect of a magnetic field, we extracted the ion beams under three conditions where without magnetic field, with magnetic field, and without magnetic field with higher laser energy to measure the beam distribution in phase space. Then we compared the relations between the plasma ion current density into the extraction gap and the Twiss parameters with each condition. We observed the effect of the magnetic field on the emission surface.

Investigation of effect of solenoid magnet on emittances of ion beam from laser ablation plasma.

PubMed

Ikeda, Shunsuke; Romanelli, Mark; Cinquegrani, David; Sekine, Megumi; Kumaki, Masafumi; Fuwa, Yasuhiro; Kanesue, Takeshi; Okamura, Masahiro; Horioka, Kazuhiko

2014-02-01

A magnetic field can increase an ion current of a laser ablation plasma and is expected to control the change of the plasma ion current. However, the magnetic field can also make some fluctuations of the plasma and the effect on the beam emittance and the emission surface is not clear. To investigate the effect of a magnetic field, we extracted the ion beams under three conditions where without magnetic field, with magnetic field, and without magnetic field with higher laser energy to measure the beam distribution in phase space. Then we compared the relations between the plasma ion current density into the extraction gap and the Twiss parameters with each condition. We observed the effect of the magnetic field on the emission surface.

Investigation of relative humidity and induced-vortex effects on aircraft icing

NASA Astrophysics Data System (ADS)

Ogretim, Egemen O.

2005-07-01

Aircraft icing is an area of research that has drawn attention since the early times of powered flight at high altitudes. Since World War II, aircraft icing research has gained a great deal of momentum, and several branches of research have developed as a result. These branches include the experimental, analytical and computational methods. With the advent of high-speed computers, the computational methods are becoming the leading icing research area due to their low cost requirements. However, a significant hindrance is the lack of a complete understanding of the icing phenomena, which leads to discrepancies between the predictions and the experiments. In recent years, there have been efforts to improve this situation by accounting for several mechanisms within the computational models. These mechanisms include the droplet splash and re-impingement, water film dynamics, and different heat transfer mechanisms. In support of enhancing the understanding of the aircraft icing process, this Ph.D. study focuses on the relative humidity effects and the interaction of the induced vortices with the droplets and the surface water. Currently the relative humidity effects are neglected in the icing prediction codes with the assumption that it can at best be a second-order effect. This Ph.D. study looks at the conditions in which the relative humidity effects can pose significant impact on the accreted ice shape. It was seen that the flow around the airfoil suction surfaces and the vortices, which have low-pressure cores, shed from the existing ice shape are highly supersaturated. Therefore, the suction surfaces and the aft regions of the main ice shape are exposed to condensation/deposition due to relative humidity effects. The time scales involved in the relative humidity effects were also investigated by using a numerical droplet growth experiment. In the particular case considered in this study, the required time to re-establish equilibrium, i.e. recover saturation

The effects of corporate social responsibility on employees' affective commitment: a cross-cultural investigation.

PubMed

Mueller, Karsten; Hattrup, Kate; Spiess, Sven-Oliver; Lin-Hi, Nick

2012-11-01

This study investigated the moderating effects of several Global Leadership and Organizational Behavior Effectiveness (GLOBE) cultural value dimensions on the relationship between employees' perceptions of their organization's social responsibility and their affective organizational commitment. Based on data from a sample of 1,084 employees from 17 countries, results showed that perceived corporate social responsibility (CSR) was positively related to employees' affective commitment (AC), after controlling for individual job satisfaction and gender as well as for nation-level differences in unemployment rates. In addition, several GLOBE value dimensions moderated the effects of CSR on AC. In particular, perceptions of CSR were more positively related to AC in cultures higher in humane orientation, institutional collectivism, ingroup collectivism, and future orientation and in cultures lower in power distance. Implications for future CSR research and cross-cultural human resources management are discussed. (c) 2012 APA, all rights reserved.

Investigating the Effects of Robot-Assisted Therapy among Children with Autism Spectrum Disorder using Bio-markers

NASA Astrophysics Data System (ADS)

Bharatharaj, Jaishankar; Huang, Loulin; Al-Jumaily, Ahmed; Elara, Mohan Rajesh; Krägeloh, Chris

2017-09-01

Therapeutic pet robots designed to help humans with various medical conditions could play a vital role in physiological, psychological and social-interaction interventions for children with autism spectrum disorder (ASD). In this paper, we report our findings from a robot-assisted therapeutic study conducted over seven weeks to investigate the changes in stress levels of children with ASD. For this study, we used the parrot-inspired therapeutic robot, KiliRo, we developed and investigated urinary and salivary samples of participating children to report changes in stress levels before and after interacting with the robot. This is a pioneering human-robot interaction study to investigate the effects of robot-assisted therapy using salivary samples. The results show that the bio-inspired robot-assisted therapy can significantly help reduce the stress levels of children with ASD.

Correlation effects in fcc-Fe(x)Ni(1-x) alloys investigated by means of the KKR-CPA.

PubMed

Minár, J; Mankovsky, S; Šipr, O; Benea, D; Ebert, H

2014-07-09

The electronic structure and magnetic properties of the disordered alloy system fcc-FexNi1-x (fcc: face centered cubic) have been investigated by means of the KKR-CPA (Korringa-Kohn-Rostoker coherent potential approximation) band structure method. To investigate the impact of correlation effects, the calculations have been performed on the basis of the LSDA (local spin density approximation), the LSDA + U as well as the LSDA + DMFT (dynamical mean field theory). It turned out that the inclusion of correlation effects hardly changed the spin magnetic moments and the related hyperfine fields. The spin-orbit induced orbital magnetic moments and hyperfine fields, on the other hand, show a pronounced and element-specific enhancement. These findings are in full accordance with the results of a recent experimental study.

An Investigation of the Effects of Black Carbon on Precipitation in the Western United States

NASA Astrophysics Data System (ADS)

Tseng, Hsien-Liang Rose

Black carbon (BC), the byproduct of incomplete combustion, is considered to be the second most important anthropogenic climate forcing agent after carbon dioxide. BC warms the atmosphere by absorbing solar radiation (direct effect), alters cloud and precipitation formation by acting as cloud condensation nuclei (indirect effect), and modifies cloud distribution via cloud burn-off (semi-direct effect). Currently, there are large discrepancies in general circulation model estimates of the influence of BC on precipitation. Even less known is how BC changes precipitation on regional scales. In the drought-stricken western United States (WUS), where BC emissions are known to affect the hydrological cycle, an investigation on how BC influences precipitation is warranted. In this study, we employ the Weather Research and Forecasting-Chemistry (WRF Chem) model (version 3.6.0) with the newly chemistry- and microphysics-coupled Fu-Liou-Gu radiation scheme to study how black carbon affects precipitation by separating BC-related effects into direct and semi-direct, and indirect effects. In this three-part study, we use a recent wet year (2005) to investigate black carbon effects. We first examine BC effects during a heavy wintertime heavy precipitation event (7-11 January 2005), a heavy summertime precipitation week for comparison to the wintertime event (20-24 July 2005), and finally, examine these same effects for the months of January to June 2005 to investigate month-long trends. We find that BC suppresses precipitation, predominantly through its direct and semi-direct effects. The direct and semi-direct effects warm the air aloft, and cool the lower levels of the atmosphere (surface dimming) through the reduction of downward shortwave radiation flux at the surface. These changes in vertical temperature increase the stability of the atmosphere and reduce convective precipitation. Convective precipitation reduction accounts for approximately 60 75% of the total

Should Cost-Effectiveness Analysis Include the Cost of Consumption Activities? AN Empirical Investigation.

PubMed

Adarkwah, Charles Christian; Sadoghi, Amirhossein; Gandjour, Afschin

2016-02-01

There has been a debate on whether cost-effectiveness analysis should consider the cost of consumption and leisure time activities when using the quality-adjusted life year as a measure of health outcome under a societal perspective. The purpose of this study was to investigate whether the effects of ill health on consumptive activities are spontaneously considered in a health state valuation exercise and how much this matters. The survey enrolled patients with inflammatory bowel disease in Germany (n = 104). Patients were randomized to explicit and no explicit instruction for the consideration of consumption and leisure effects in a time trade-off (TTO) exercise. Explicit instruction to consider non-health-related utility in TTO exercises did not influence TTO scores. However, spontaneous consideration of non-health-related utility in patients without explicit instruction (60% of respondents) led to significantly lower TTO scores. Results suggest an inclusion of consumption costs in the numerator of the cost-effectiveness ratio, at least for those respondents who spontaneously consider non-health-related utility from treatment. Results also suggest that exercises eliciting health valuations from the general public may include a description of the impact of disease on consumptive activities. Copyright © 2015 John Wiley & Sons, Ltd.

An Investigation of the Differential Effects of Group versus Individual Treatment on Vocational Indecision and Indecisiveness.

ERIC Educational Resources Information Center

Cooper, Stewart E.; Van Matre, Gene

The differential effects of individual versus group treatment on career indecision and general indecisiveness among career counseling clients were investigated. Data were obtained from 24 career-undecided students seeking vocational counseling through the counseling center of a midwestern state university. Twelve subjects participated in the group…

A Randomized Trial Investigating the Effect of a Brief Lifestyle Intervention on Freshman-Year Weight Gain

ERIC Educational Resources Information Center

Middleton, Kathryn R.; Perri, Michael G.

2014-01-01

Objective: The current study was a randomized controlled trial investigating the effect of an innovative, short-term lifestyle intervention on weight gain in female freshman college students. Participants: Ninety-five freshmen were recruited from a large public university in the United States. Methods: Participants completed baseline assessments…

An experimental investigation of the effect of walls on gas-liquid flows through fixed particle beds.

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

Cooper, Marcia A.; Cote, Raymond O.; Torczynski, John Robert

The effect of particle diameter on downward co-current gas-liquid flow through a fixed bed of particles confined within a cylindrical column is investigated. Several hydrodynamic regimes that depend strongly on the properties of the gas stream, the liquid stream, and the packed particle bed are known to exist within these systems. This experimental study focuses on characterizing the effect of wall confinement on these hydrodynamic regimes as the diameter d of the spherical particles becomes comparable to the column diameter D (or D/d becomes order-unity). The packed bed consists of polished, solid, spherical, monodisperse particles (beads) with mean diameter inmore » the range of 0.64-2.54 cm. These diameters yield D/d values between 15 and 3.75, so this range overlaps and extends the previously investigated range for two-phase flow, Measurements of the pressure drop across the bed and across the pulses are obtained for varying gas and liquid flow rates.« less

Investigation of neuropsychopharmacological effects of a polyherbal formulation on the learning and memory process in rats.

PubMed

Shah, Js; Goyal, Rk

2011-04-01

To investigate the neuropsychopharmacological effect of a polyherbal formulation (PHF) on the learning and memory processes in rats. PHF contains Withania somnifera (Ashwagandha), Nardostachys jatamansi (Jatamansi), Rauwolfia serpentina (Sarpagandha), Evolvulus alsinoides (Shankhpushpi), Asparagus racemosus (Shatavari), Emblica officinalis (Amalki), Mucuna pruriens (Kauch bij extract), Hyoscyamus niger (Khurasani Ajmo), Mineral resin (Shilajit), Pearl (Mukta Shukhti Pishti), and coral calcium (Praval pishti). Its effect (500 mg / kg, p.o.) on the learning and memory processes was tested. The activity of PHF on memory acquisition and retention was studied using passive avoidance learning and elevated plus maze model (EPM) in rats. The animals treated with PHF showed a significant decrease in transfer latency as compared to the control group in EPM. PHF also produced significant improvement in passive avoidance acquisition and memory retrieval, as compared to the controls and reduced the latency to reach the shock free zone (SFZ) after 24 hours. The PHF produces significant improvement in passive avoidance acquisition and memory retrieval in rats, which needs further investigation.

Investigation of the effects of inlet shapes on fan noise radiation

NASA Technical Reports Server (NTRS)

Clark, T. L.; Slotboom, D. R.; Vaidya, P. G.

1981-01-01

The effect of inlet shape on forward radiated fan tone noise directivities was investigated under experimentally simplified zero flow conditions. Simulated fan tone noise was radiated to the far field through various shaped zero flow inlets. Baseline data were collected for the simplest baffled and unbaffled straight pipe inlets. These data compared well with prediction. The more general inlet shapes tested were the conical, circular, and exponential surfaces of revolution and an asymmetric inlet achieved by cutting a straight pipe inlet at an acute angle. Approximate theories were developed for these general shapes and some comparisons with data are presented. The conical and exponential shapes produced directivities that differed considerably from the baseline data while the circular shape produced directivities similar to the baseline data. The asymmetric inlet produced asymmetric directivities with significant reductions over the straight pipe data for some angles.

Investigating the effectiveness of technologies applied to assist seniors: A systematic literature review.

PubMed

Khosravi, Pouria; Ghapanchi, Amir Hossein

2016-01-01

Recently, a number of Information and Communication Technologies have emerged with the aim to provide innovative and efficient ways to help seniors in their daily life and to reduce the cost of healthcare. Studies have been conducted to introduce an assistive technology to support seniors and to investigate the acceptance of these assistive technologies; however, research illustrating the effectiveness of assistive technologies is scant. This study undertakes a systematic literature review of ScienceDirect, PubMed, ProQuest and IEEE Explore databases to investigate current empirical studies on the assistive technologies applied in aged care. Our systematic review of an initial set of 2035 studies published from 2000 to 2014 examines the role of assistive technologies in seniors' daily lives, from enhancements in their mobility to improvements in the social connectedness and decreases in readmission to hospitals. This study found eight key issues in aged care that have been targeted by researchers from different disciplines (e.g., ICT, health and social science), namely, dependent living, fall risk, chronic disease, dementia, social isolation, depression, poor well-being, and poor medication management. This paper also identified the assistive technologies that have been proposed to overcome those problems, and we categorised these assistive technologies into six clusters, namely, general ICT, robotics, telemedicine, sensor technology, medication management applications, and video games. In addition, we analyzed the effectiveness of the identified technologies and noted that some technologies can change and enhance seniors' daily lives and relieve their problems. Our analysis showed a significant growth in the number of publications in this area in the past few years. It also showed that most of the studies in this area have been conducted in North America. Assistive technologies are a reality and can be applied to improve quality of life, especially among older age

Theoretical investigation of two-particle two-hole effects on spin-isospin excitations through charge-exchange reactions

NASA Astrophysics Data System (ADS)

Fukui, Tokuro; Minato, Futoshi

2017-11-01

Background: Coherent one-particle one-hole (1p1h) excitations have given us effective insights into general nuclear excitations. However, the two-particle two-hole (2p2h) excitation beyond 1p1h is now recognized as critical for the proper description of experimental data of various nuclear responses. Purpose: The spin-flip charge-exchange reactions 48Ca(p ,n )48Sc are investigated to clarify the role of the 2p2h effect on their cross sections. The Fermi transition of 48Ca via the (p ,n ) reaction is also investigated in order to demonstrate our framework. Methods: The transition density is calculated microscopically with the second Tamm-Dancoff approximation, and the distorted-wave Born approximation is employed to describe the reaction process. A phenomenological one-range Gaussian interaction is used to prepare the form factor. Results: For the Fermi transition, our approach describes the experimental behavior of the cross section better than the Lane model, which is the conventional method. For spin-flip excitations including the GT transition, the 2p2h effect decreases the magnitude of the cross section and does not change the shape of the angular distribution. The Δ l =2 transition of the present reaction is found to play a negligible role. Conclusions: The 2p2h effect will not change the angular-distributed cross section of spin-flip responses. This is because the transition density of the Gamow-Teller response, the leading contribution to the cross section, is not significantly varied by the 2p2h effect.

Investigating the Effectiveness of an Active Learning Based-Interactive Conceptual Instruction (ALBICI) on Electric Field Concept

ERIC Educational Resources Information Center

Samsudin, Achmad; Suhandi, Andi; Rusdiana, Dadi; Kaniawati, Ida; Costu, Bayram

2016-01-01

The aim of this study was to develop an Active Learning Based-Interactive Conceptual Instruction (ALBICI) model through PDEODE*E tasks (stands for Predict, Discuss, Explain, Observe, Discuss, Explore, and Explain) for promoting conceptual change and investigating its effectiveness of pre-service physics teachers' understanding on electric field…

Investigation of local strain distribution and linear electro-optic effect in strained silicon waveguides.

PubMed

Chmielak, Bartos; Matheisen, Christopher; Ripperda, Christian; Bolten, Jens; Wahlbrink, Thorsten; Waldow, Michael; Kurz, Heinrich

2013-10-21

We present detailed investigations of the local strain distribution and the induced second-order optical nonlinearity within strained silicon waveguides cladded with a Si₃N₄ strain layer. Micro-Raman Spectroscopy mappings and electro-optic characterization of waveguides with varying width w(WG) show that strain gradients in the waveguide core and the effective second-order susceptibility χ(2)(yyz) increase with reduced w(WG). For 300 nm wide waveguides a mean effective χ(2)(yyz) of 190 pm/V is achieved, which is the highest value reported for silicon so far. To gain more insight into the origin of the extraordinary large optical second-order nonlinearity of strained silicon waveguides numerical simulations of edge induced strain gradients in these structures are presented and discussed.

Investigation of arterial gas occlusions. [effect of noncondensable gases on high performance heat pipes

NASA Technical Reports Server (NTRS)

Saaski, E. W.

1974-01-01

The effect of noncondensable gases on high-performance arterial heat pipes was investigated both analytically and experimentally. Models have been generated which characterize the dissolution of gases in condensate, and the diffusional loss of dissolved gases from condensate in arterial flow. These processes, and others, were used to postulate stability criteria for arterial heat pipes under isothermal and non-isothermal condensate flow conditions. A rigorous second-order gas-loaded heat pipe model, incorporating axial conduction and one-dimensional vapor transport, was produced and used for thermal and gas studies. A Freon-22 (CHCIF2) heat pipe was used with helium and xenon to validate modeling. With helium, experimental data compared well with theory. Unusual gas-control effects with xenon were attributed to high solubility.

Multiscale Modelling for investigating single molecule effects on the mechanics of actin filaments

NASA Astrophysics Data System (ADS)

A, Deriu Marco; C, Bidone Tamara; Laura, Carbone; Cristina, Bignardi; M, Montevecchi Franco; Umberto, Morbiducci

2011-12-01

This work presents a preliminary multiscale computational investigation of the effects of nucleotides and cations on the mechanics of actin filaments (F-actin). At the molecular level, Molecular Dynamics (MD) simulations are employed to characterize the rearrangements of the actin monomers (G-actin) in terms of secondary structures evolution in physiological conditions. At the mesoscale level, a coarse grain (CG) procedure is adopted where each monomer is represented by means of Elastic Network Modeling (ENM) technique. At the macroscale level, actin filaments up to hundreds of nanometers are assumed as isotropic and elastic beams and characterized via Rotation Translation Block (RTB) analysis. F-actin bound to adenosine triphosphate (ATP) shows a persistence length around 5 μm, while actin filaments bound to adenosine diphosphate (ADP) have a persistence length of about 3 μm. With magnesium bound to the high affinity binding site of G-actin, the persistence length of F-actin decreases to about 2 μm only in the ADP-bound form of the filament, while the same ion has no effects, in terms of stiffness variation, on the ATP-bound form of F-actin. The molecular mechanisms behind these changes in flexibility are herein elucidated. Thus, this study allows to analyze how the local binding of cations and nucleotides on G-actin induce molecular rearrangements that transmit to the overall F-actin, characterizing shifts of mechanical properties, that can be related with physiological and pathological cellular phenomena, as cell migration and spreading. Further, this study provides the basis for upcoming investigating of network and cellular remodelling at higher length scales.

Investigations of Effect of Rotary EDM Electrode on Machining Performance of Al6061 Alloy

NASA Astrophysics Data System (ADS)

Robinson Smart, D. S.; Jenish Smart, Joses; Periasamy, C.; Ratna Kumar, P. S. Samuel

2018-04-01

Electric Discharge Machining is an essential process which is being used for machining desired shape using electrical discharges which creates sparks. There will be electrodes subjected to electric voltage and which are separated by a dielectric liquid. Removing of material will be due to the continuous and rapid current discharges between two electrodes.. The spark is very carefully controlled and localized so that it only affects the surface of the material. Usually in order to prevent the defects which are arising due to the conventional machining, the Electric Discharge Machining (EDM) machining is preferred. Also intricate and complicated shapes can be machined effectively by use of Electric Discharge Machining (EDM). The EDM process usually does not affect the heat treat below the surface. This research work focus on the design and fabrication of rotary EDM tool for machining Al6061alloy and investigation of effect of rotary tool on surface finish, material removal rate and tool wear rate. Also the effect of machining parameters of EDM such as pulse on & off time, current on material Removal Rate (MRR), Surface Roughness (SR) and Electrode wear rate (EWR) have studied. Al6061 alloy can be used for marine and offshore applications by reinforcing some other elements. The investigations have revealed that MRR (material removal rate), surface roughness (Ra) have been improved with the reduction in the tool wear rate (TWR) when the tool is rotating instead of stationary. It was clear that as rotary speed of the tool is increasing the material removal rate is increasing with the reduction of surface finish and tool wear rate.

Investigating the effects of laryngotracheal stenosis on upper airway aerodynamics.

PubMed

Cheng, Tracy; Carpenter, David; Cohen, Seth; Witsell, David; Frank-Ito, Dennis O

2018-04-01

Very little is known about the impact of laryngotracheal stenosis (LTS) on inspiratory airflow and resistance, especially in air hunger states. This study investigates the effect of LTS on airway resistance and volumetric flow across three different inspiratory pressures. Head-and-neck computed tomography scans of 11 subjects from 2010 to 2016 were collected. Three-dimensional reconstructions of the upper airway from the nostrils to carina, including the oral cavity, were created for one subject with a normal airway and for 10 patients with LTS. Airflow simulations were conducted using computational fluid dynamics modeling at three different inspiratory pressures (10, 25, 40 pascals [Pa]) for all subjects under two scenarios: 1) inspiration through nostrils only (MC), and 2) through both nostrils and mouth (MO). Volumetric flows in the normal subject at the three inspiratory pressures were considerably higher (MC: 11.8-26.1 L/min; MO: 17.2-36.9 L/min) compared to those in LTS (MC: 2.86-6.75 L/min; MO: 4.11-9.00 L/min). Airway resistances in the normal subject were 0.051 to 0.092 pascal seconds per milliliter (Pa.s)/mL (MC) and 0.035-0.065 Pa.s/mL (MO), which were approximately tenfold lower than those of subjects with LTS: 0.39 to 0.89 Pa.s/mL (MC) and 0.45 to 0.84 Pa.s/mL (MO). Furthermore, subjects with glottic stenosis had the greatest resistance, whereas subjects with subglottic stenosis had the greatest variability in resistance. Subjects with tracheal stenosis had the lowest resistance. This pilot study demonstrates that LTS increases resistance and decreases airflow. Mouth breathing significantly improved airflow and resistance but cannot completely compensate for the effects of stenosis. Furthermore, location of stenosis appears to modulate the effect of the stenosis on resistance differentially. NA. Laryngoscope, 128:E141-E149, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

An Empirical Investigation of Mode of Delivery, Ratings of Speech Characteristics, and Perceptions of Speaking Effectiveness.

ERIC Educational Resources Information Center

Vallin, Marlene Boyd

A study tested those theories upon which instruction and curriculum in speech and public communication are based. The study investigated the relationship of mode of delivery on ratings of individual speech characteristics as well as the relationship of these perceptions of effectiveness in a public communication setting. Twenty-four videotapes of…

Abundance and Speciation of Water and Sulfate at Gusev Crater and Meridiani Planum

NASA Technical Reports Server (NTRS)

Ming, D. W.; Clark, B. C.; Klingelhoefer, G.; Gellert, R.; Rodionov, D.; Schroeder, C.; deSouza, P.; Yen, A.

2005-01-01

A major science goal of the Mars Exploration Rover (MER) mission is to search for evidence of water activity, and direct mineralogical evidence for aqueous activity has been reported for Meridiani Planum in the form of the iron sulfate hydroxide mineral jarosite and at Gusev crater in the form of goethite. The Spirit and Opportunity rovers have each collected 110+ Moessbauer (MB) and 75+ Alpha Particle X-Ray Spectrometer (APXS) spectra from Gusev crater and Meridiani Planum [1 - 4]. In this abstract, we use mineralogical and elemental data, primarily from the Moessbauer and APXS instruments, to infer the speciation and estimate the abundance of sulfate and water (as either the H2O molecule or the hydroxyl anion) at Gusev crater and Meridiani Planum. Throughout the abstract, we adopt a format for mineral formulas that shows water explicitly rather than the usual practice of structure-based formulas (e.g., for goethite we write Fe2O3xH2O instead of FeOOH).

Investigation of a direct effect of nanosecond pulse electric fields on mitochondria

NASA Astrophysics Data System (ADS)

Estlack, Larry E.; Roth, Caleb C.; Cerna, Cesario Z.; Wilmink, Gerald J.; Ibey, Bennett L.

2014-03-01

The unique cellular response to nanosecond pulsed electric field (nsPEF) exposure, as compared to longer pulse exposure, has been theorized to be due to permeabilization of intracellular organelles including the mitochondria. In this investigation, we utilized a high-throughput oxygen and pH sensing system (Seahorse® XF24 extracellular flux analyzer) to assess the mitochondrial activity of Jurkat and U937 cells after nsPEF. The XF Analyzer uses a transient micro-chamber of only a few μL in specialized cell culture micro-plates to enable oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) to be monitored in real-time. We found that for nsPEF exposures of 10 pulses at 10-ns pulse width and at 50 kV/cm e-field, we were able to cause an increase in OCR in both U937 and Jurkat cells. We also found that high pulse numbers (>100) caused a significant decrease in OCR. Higher amplitude 150 kV/cm exposures had no effect on U937 cells and yet they had a deleterious effect on Jurkat cells, matching previously published 24 hour survival data. These results suggest that the exposures were modulating metabolic activity in cells possibly due to direct effects on the mitochondria themselves. To validate this hypothesis, we isolated mitochondria from U937 cells and exposed them similarly and found no significant change in metabolic activity for any pulse number. In a final experiment, we removed calcium from the buffer solution that the cells were exposed in and found that no significant enhancement in metabolic activity was observed. These results suggest that direct permeabilization of the mitochondria is unlikely a primary effect of nsPEF exposure and calcium-mediated intracellular pathway activation is likely responsible for observed pulse-induced mitochondrial effects.

Experimental investigation of CNT effect on curved beam strength and interlaminar fracture toughness of CFRP laminates

NASA Astrophysics Data System (ADS)

Arca, M. A.; Coker, D.

2014-06-01

High mechanical properties and light weight structures of composite materials and advances in manufacturing processes have increased the use of composite materials in the aerospace and wind energy industries as a primary load carrying structures in complex shapes. However, use of composite materials in complex geometries such as L-shaped laminates creates weakness at the radius which causes delamination. Carbon nanotubes (CNTs) is preferred as a toughening materials in composite matrices due to their high mechanical properties and aspect ratios. However, effect of CNTs on curved beam strength (CBS) is not investigated in literature comprehensively. The objective of this study is to investigate the effect of CNT on Mode I and Mode II fracture toughness and CBS. L-shaped beams are fabric carbon/epoxy composite laminates manufactured by hand layup technique. Curved beam composite laminates were subjected to four point bending loading according to ASTM D6415/D6415M-06a. Double cantilever beam (DCB) tests and end notch flexure (ENF) tests were conducted to determine mode-I and mode-II fracture toughness, respectively. Preliminary results show that 3% CNT addition to the resin increased the mode-I fracture toughness by %25 and mode-II fracture toughness by %10 compared to base laminates. In contrast, no effect on curved beam strength was found.

Investigation of the effect of Mg doping for improvements of optical and electrical properties

NASA Astrophysics Data System (ADS)

Caglar, Mujdat; Caglar, Yasemin; Ilican, Saliha

2016-03-01

Sol-gel spin coating method was used for the deposition of nanostructured undoped and Mg doped ZnO films. The effects of magnesium incorporation on the crystalline structure were investigated by XRD measurements and the structural deterioration was observed in the crystalline quality of the films with respect to increasing in Mg doping. All the samples exhibited a wurtzite structure. From the scanning electron microscopy (SEM) images obtained to investigate the surface morphology it was detected that an increase in Mg doping caused an improvement on the surface roughness and a reduction in the number of voids on the surface. To evaluate the absorption edges of the produced samples depending on the Mg, different methods were used and according to the obtained results, a shifting towards to high energies for the optical band gap was observed in each method. By using the single oscillator model, developed by DiDomenico and Wemple, the refractive index dispersion of the films was analyzed. Eo and Ed values of the 5% Mg doped film were found to be 5.76 eV and 11.80 eV, respectively. Within the scope of electrical properties, from Hall effect measurements, it was determined that all the films exhibited n-type behavior and the carrier concentration increased from 1.49×1016 to 1.20×1017 cm-3 with increasing Mg doping.

Flight Investigation of the Effects of Pressure-Belt Tubing Size on Measured Pressure Distributions

NASA Technical Reports Server (NTRS)

Rivers, Natale A.; vanDam, Cornielious P.; Brown, Phillip W.; Rivers, Robert A.

2001-01-01

The pressure-belt technique is commonly used to measure pressure distributions on lifting and nonlifting surfaces where flush, through-the-surface measurements are not possible. The belts, made from strips of small-bore, flexible plastic tubing, are surface-mounted by a simple, nondestructive method. Additionally, the belts require minimal installation time, thus making them much less costly to install than flush-mounted pressure ports. Although pressure belts have been used in flight research since the early 1950s, only recently have manufacturers begun to produce thinner, more flexible tubing, and thin, strong adhesive tapes that minimize the installation-induced errors on the measurement of surface pressures. The objective of this investigation was to determine the effects of pressure-belt tubing size on the measurement of pressure distributions. For that purpose, two pressure belts were mounted on the right wing of a single-engine, propeller-driven research airplane. The outboard pressure belt served as a baseline for the measurement and the comparison of effects. Each tube had an outer diameter (OD) of 0.0625 in. The inboard belt was used to evaluate three different tube sizes: 0.0625-, 0.1250-, and 0.1875-in. OD. A computational investigation of tube size on pressure distribution also was conducted using the two-dimensional Multielement Streamtube Euler Solver (MSES) code.

Wind tunnel investigation of helicopter rotor wake effects on three helicopter fuselage models

NASA Technical Reports Server (NTRS)

Wilson, J. C.; Mineck, R. E.

1974-01-01

The effects of rotor downwash on helicopter fuselage aerodynamic characteristics were investigated. A rotor model for generating the downwash was mounted close to each of three fuselage models. The main report presents the force and moment data in both graphical and tabular form and the pressure data in graphical form. This supplement presents the pressure data in tabular form. Each run or parameter sweep is identified by a unique run number. The data points in each run are identified by a point number. The pressure data can be matched to the force data by matching the run and point number.

Investigation of MeV-Cu implantation and channeling effects into porous silicon formation

NASA Astrophysics Data System (ADS)

Ahmad, M.; Naddaf, M.

2011-11-01

P-type (1 1 1) silicon wafers were implanted by copper ions (2.5 MeV) in channeling and random directions using ion beam accelerator of the Atomic Energy Commission of Syria (AECS). The effect of implantation direction on formation process of porous silicon (PS) using electrochemical etching method has been investigated using scanning electron microscope (SEM) and photoluminescence (PL) techniques. SEM observations revealed that the size, shape and density of the formed pores are highly affected by the direction of beam implantation. This in turn is seen to influence the PL behavior of the PS.

Effects of industrial and investigator disturbance on Arctic-nesting geese

USGS Publications Warehouse

Meixell, Brandt W.; Flint, Paul L.

2017-01-01

Oil and gas development on the Arctic Coastal Plain (ACP) of Alaska, USA may have effects on Arctic-nesting birds. To estimate effects of industrial activity and investigator disturbance on avian productivity, we monitored nests of greater white-fronted geese (Anser albifrons) with digital cameras and periodic nest visits during 2013–2014 at 2 sites on the ACP. A disturbed site was adjacent to human-made infrastructure and industrial clean-up activities initiated at the onset of the study and a control site was >2 km from sources of industrial disturbance. We assessed variation in estimates of incubation constancy, nest survival, and predator behavior relative to site, year, and distance from industrial activity using nest photographs obtained at 1-minute intervals. We compared analysis of hourly nest survival informed by intensive monitoring with cameras to analysis of daily nest survival informed by traditional nest visit data obtained at intervals of 5–7 days to assess how method and time scale of sampling affect ecological inference. Geese in both sites exhibited high levels of nest attendance and initiated incubation breaks less than once per day. Observer-caused incubation breaks associated with nest visits ( = 37.8 min) were longer than other types of incubation breaks ( = 8.7 min), demonstrating a differential response by nesting geese to direct human encroachment versus indirect vehicular and aircraft traffic. During both years, geese were absent from nests more frequently in the disturbed ( = 0.9 breaks/day) than control ( = 0.6 breaks/day) site, and this break frequency was slightly higher for nests closer to industrial activity. In the year with high rates of depredation, nest survival was positively related to distance from industrial activity and abandoned infrastructure, consistent with predictions of industry-caused effects. This relationship, however, was not evident in the year with reduced predation pressure, likely

Investigate the Effect of Thawing Process on the Self-Assembly of Silk Protein for Tissue Applications.

PubMed

Nguyen, Hiep Thi; Luong, Hien Thu; Nguyen, Hai Dai; Tran, Hien Anh; Huynh, Khon Chan; Vo, Toi Van

2017-01-01

Biological self-assembly is a process in which building blocks autonomously organize to form stable supermolecules of higher order and complexity through domination of weak, noncovalent interactions. For silk protein, the effect of high incubating temperature on the induction of secondary structure and self-assembly was well investigated. However, the effect of freezing and thawing on silk solution has not been studied. The present work aimed to investigate a new all-aqueous process to form 3D porous silk fibroin matrices using a freezing-assisted self-assembly method. This study proposes an experimental investigation and optimization of environmental parameters for the self-assembly process such as freezing temperature, thawing process, and concentration of silk solution. The optical images demonstrated the possibility and potential of -80ST48 treatment to initialize the self-assembly of silk fibroin as well as controllably fabricate a porous scaffold. Moreover, the micrograph images illustrate the assembly of silk protein chain in 7 days under the treatment of -80ST48 process. The surface morphology characterization proved that this method could control the pore size of porous scaffolds by control of the concentration of silk solution. The animal test showed the support of silk scaffold for cell adhesion and proliferation, as well as the cell migration process in the 3D implantable scaffold.

Investigate the Effect of Thawing Process on the Self-Assembly of Silk Protein for Tissue Applications

PubMed Central

Tran, Hien Anh; Huynh, Khon Chan; Vo, Toi Van

2017-01-01

Biological self-assembly is a process in which building blocks autonomously organize to form stable supermolecules of higher order and complexity through domination of weak, noncovalent interactions. For silk protein, the effect of high incubating temperature on the induction of secondary structure and self-assembly was well investigated. However, the effect of freezing and thawing on silk solution has not been studied. The present work aimed to investigate a new all-aqueous process to form 3D porous silk fibroin matrices using a freezing-assisted self-assembly method. This study proposes an experimental investigation and optimization of environmental parameters for the self-assembly process such as freezing temperature, thawing process, and concentration of silk solution. The optical images demonstrated the possibility and potential of −80ST48 treatment to initialize the self-assembly of silk fibroin as well as controllably fabricate a porous scaffold. Moreover, the micrograph images illustrate the assembly of silk protein chain in 7 days under the treatment of −80ST48 process. The surface morphology characterization proved that this method could control the pore size of porous scaffolds by control of the concentration of silk solution. The animal test showed the support of silk scaffold for cell adhesion and proliferation, as well as the cell migration process in the 3D implantable scaffold. PMID:28367442

Development of a New Apparatus for Investigating Acoustic Effects on Hydraulic Properties of Low-Permeability Geo-Materials

NASA Astrophysics Data System (ADS)

Nakajima, H.; Sawada, A.; Sugita, H.; Takeda, M.; Komai, T.; Zhang, M.

2006-12-01

Remediation of polluted soils and groundwater contaminated by heavy metals and non-aqueous phase liquids has been one of the challenging issues in the field of geo-environments. In-situ removal of the contaminants from low permeable soils, such as clay strata, is particularly difficult because of the low mobility, strong adsorption, and/or other various interactions within soils. Thus current remediation techniques, such as pump- and-treat method and even eletrokinetic method, generally suffer from low recovery rates and/or economically unacceptable long remediation periods. A perspective improvement in remediation technology is to couple the electrokinetic method with an application of acoustic waves. This so-called Electro-Acoustic Soil Decontamination (EASD) method has been proposed by Battelle Columbus Labs.(Muralidhara et al. 1990). Simultaneous application of an electric field and an acoustic field may produce a synergistic effect and result in further enhancement of water transport by electro-osmosis in principle, but there is still no fundamental data for the design of EASD method in practical applications. A number of investigations have shown that an application of acoustic waves can increase hydraulic conductivity and mobility of non-aqueous phase liquids in porous media. Most of the prior and ongoing researches in this area have been focused on increasing production from declining oil and gas reservoirs. During several field tests by the oil and gas industries, increases in oil production rates by 20% or more have been reported. However, underlying physical mechanisms for acoustically enhanced fluid transport are not adequately understood. In addition, majority of the past investigations has dealt with applications of large amplitude of acoustic waves to relatively permeable soils or fractured rocks, and there is little information if acoustic wave effectively enhances flow and contaminant transport for less permeable clayey soils. To evaluate the

Nuclear microprobe investigation of the effects of ionization and displacement damage in vertical, high voltage GaN diodes

DOE PAGES

Vizkelethy, G.; King, M. P.; Aktas, O.; ...

2016-12-02

Radiation responses of high-voltage, vertical gallium-nitride (GaN) diodes were investigated using Sandia National Laboratories’ nuclear microprobe. Effects of the ionization and the displacement damage were studied using various ion beams. We found that the devices show avalanche effect for heavy ions operated under bias well below the breakdown voltage. Here, the displacement damage experiments showed a surprising effect for moderate damage: the charge collection efficiency demonstrated an increase instead of a decrease for higher bias voltages.

Nuclear microprobe investigation of the effects of ionization and displacement damage in vertical, high voltage GaN diodes

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

Vizkelethy, G.; King, M. P.; Aktas, O.

Radiation responses of high-voltage, vertical gallium-nitride (GaN) diodes were investigated using Sandia National Laboratories’ nuclear microprobe. Effects of the ionization and the displacement damage were studied using various ion beams. We found that the devices show avalanche effect for heavy ions operated under bias well below the breakdown voltage. Here, the displacement damage experiments showed a surprising effect for moderate damage: the charge collection efficiency demonstrated an increase instead of a decrease for higher bias voltages.

Investigation on the Effects of 12 Days Intensive Competition on Some Blood Parameters of Basketball Players

ERIC Educational Resources Information Center

Gencer, Yildirim Gokhan; Coskun, Funda; Sarikaya, Mucahit; Kaplan, Seyhmus

2018-01-01

The aim of this study is to investigate the effect of intensive basketball competitions (10 official basketball games in 12 days intensive competition period) on blood parameters of basketball players. Blood samples were taken from the basketball players of the university team. The players were training regularly and they had no regular health…

An Investigation of the Effectiveness of Two Educational Programs in View of the Students' Previous Experiences.

ERIC Educational Resources Information Center

Bell, Anita Iris

This study investigated the possibility that the effectiveness of an educational program for an individual student is dependent on his or her background. A 101-item biographical data questionnaire was administered to the parents of 43 Follow Through and 38 non-Follow Through students who had just finished the third grade. The biographical…

Ultrastructural investigation of the protective effects of propolis on bleomycin induced pulmonary fibrosis.

PubMed

Bilgin, G; Kismet, K; Kuru, S; Kaya, F; Senes, M; Bayrakceken, Y; Yumusak, N; Celikkan, F T; Erdemli, E; Celemli, O G; Sorkun, K; Koca, G

2016-01-01

We investigated the antioxidant and anti-inflammatory effects of propolis on bleomycin induced lung fibrosis and compared these effects to prednisolone treatment. Forty rats were divided into four groups of ten: group 1 was treated with intratracheal infusion of 0.2 ml physiological saline followed by daily treatment with 0.5 ml physiological saline for 20 days. In the remaining groups (groups 2 - 4), 5 mg/kg bleomycin was given via the trachea. Rats in group 2 were given 0.5 ml physiological saline. Rats in group 3 were treated with 100 mg/kg propolis, and 10 mg/kg prednisolone was given to rats in group 4. The treatments for all groups were continued for 20 days. On postoperative day 21, blood and lung samples were taken for biochemistry, histopathology and electron microscopy evaluation. We compared oxidative stress parameters and found lower malondialdehyde and myeloperoxidase levels, and higher total sulfhydryl levels and catalase activities for the bleomycin + propolis group than for the bleomycin and bleomycin + prednisolone groups. The highest mean fibrosis score was detected in the bleomycin group. Although the mean fibrosis scores of the bleomycin + propolis and bleomycin + prednisolone groups were not significantly different, electron microscopy revealed that propolis diminished bleomycin induced lung fibrosis more effectively than prednisolone. The effects of propolis might be due to its potent antioxidant and anti-inflammatory properties.

Effects of the chemical environment on the spectroscopic properties of clays: Applications for Mars

NASA Technical Reports Server (NTRS)

Bishop, Janice L.; Pieters, Carle M.

1992-01-01

Laboratory studies of Mars soil analogs pose unique problems, since soils interact readily with their environment and exhibit variable characteristics depending on the environment. We have performed a series of experiments focusing on the spectral properties of clays and how they vary as a function of composition and environment, including examination of fundamental as well as overtone absorptions, that occur in the mid- and near-IR, respectively. Smectite clays have been selected in our laboratory experiments as a primary surface analog for Mars because of their compatibility with results of the Viking biology experiments, their stability under current martian conditions, and their compatibility with reflectance spectra of Mars. We prepared a number of monoionic montmorillonites in order to examine the influence of cations on the water molecules in the clay interlayer region. Moessbauer spectra of several montmorillonites with variable amounts of interlayer iron confirm the presence of ferrihydrite.

Investigation of terpinen-4-ol effects on vascular smooth muscle relaxation.

PubMed

Maia-Joca, Rebeca Peres Moreno; Joca, Humberto Cavalcante; Ribeiro, Francisca Jéssica Penha; do Nascimento, Renata Vieira; Silva-Alves, Kerly Shamyra; Cruz, Jader S; Coelho-de-Souza, Andrelina Noronha; Leal-Cardoso, José Henrique

2014-10-12

This study investigated the mechanisms underlying the vascular effects of terpinen-4-ol in isolated rat aortic ring preparations. The thoracic aortae of healthy rats were submitted to isometric tension recording. Membrane resting potential and input membrane resistance were measured by conventional microelectrode technique. Terpinen-4-ol reversibly relaxed endothelium-containing preparations pre-contracted with high K(+) and phenylephrine with IC50 values of 421.43 μM and 802.50 μM, respectively. These effects were significantly reduced by vascular endothelium removal. In Ca(2+)-free and high K(+) (80 mM) medium, the contractions produced by Ba(2+) were reduced by terpinen-4-ol (100-1000 μM) in a concentration-dependent manner. In aortic rings maintained under Ca(2+)-free conditions, terpinen-4-ol significantly reduced the contractions induced by either phenylephrine (1 μM) or phorbol 12,13-dibutyrate (1 μM). Terpinen-4-ol (10-1000 μM) also relaxed the contractions evoked by BAYK-8644 (3 μM) with an IC50 of 454.23 μM. Neither membrane resting potential nor input resistance of smooth muscle cells was altered by terpinen-4-ol exposure. The present results suggest that terpinen-4-ol induced vascular smooth muscle relaxation that was preferentially due to the inhibition of electromechanical pathways related to calcium influx through voltage-operated calcium channels. Copyright © 2014 Elsevier Inc. All rights reserved.

Diagnostics Upgrades for Investigations of HOM Effects in TESLA-type SCRF Cavities

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

Lumpkin, A. H.; Edstrom Jr., D.; Ruan, J.

We describe the upgrades to diagnostic capabilities on the Fermilab Accelerator Science and Technology (FAST) electron linear accelerator that will allow investigations of the effects of high-order modes (HOMs) in SCRF cavities on macropulse-average beam quality. We examine the dipole modes in the first pass-band generally observed in the 1.6-1.9 GHz regime for TESLA-type SCRF cavities due to uniform transverse beam offsets of the electron beam. Such cavities are the basis of the accelerators such as the European XFEL and the proposed MaRIE XFEL facility. Preliminary HOM detector data, prototype BPM test data, and first framing camera OTR data withmore » ~20- micron spatial resolution at 250 pC per bunch will be presented.« less

AN EXPLORATORY STUDY INVESTIGATING THE EFFECTS OF A TREATMENT MANUAL FOR VIDEO GAME ADDICTION.

PubMed

Pallesen, Ståle; Lorvik, Ingjerd Meen; Bu, Eli Hellandsjø; Molde, Helge

2015-10-01

This study investigated the effects of a manualized therapy for video game addiction in 12 males, ages 14-18 yr. The manual was based on cognitive-behavioral therapy, short-term strategic family therapy, solution-focused therapy, and motivational interviewing. Treatment response was reported by the patients, their mothers, and the therapists. The patients reported moderate (but statistically non-significant) improvement from pre- to post-treatment. The mothers, however, reported large effects and statistically significant improvement from pre- to post-treatment. The therapists reported marked or moderate treatment response in six of the 12 patients. The ratings of change by mothers converged well with the views of change of both the patients and therapists, whereas the convergence of views on change between the two latter sources was far lower.

Determination of doping effects on Si and GaAs bulk samples properties by photothermal investigations

NASA Astrophysics Data System (ADS)

Abroug, Sameh; Saadallah, Faycel; Yacoubi, Noureddine

2007-11-01

The knowledge of doping effects on optical and thermal properties of semiconductors is crucial for the development of opto-electronic compounds. The purpose of this work is to investigate these effects by mirage effect technique and spectroscopic ellipsometry SE. The near gap optical spectra are obtained from photothermal signal for differently doped Si and GaAs bulk samples. However, the above bandgap absorption is determined from SE. These spectra show that absorption in the near IR increases with dopant density and also the bandgap shifts toward low energies. This behavior is due to free carrier absorption which could be obtained by subtracting phonon-assisted absorption from the measured spectrum. This carrier absorption is related to the dopant density through a semi-empirical model. We have also used the photothermal signal phase to measure the influence of doping on thermal diffusivity.

Integrating 21st Century Skills into Teaching English: Investigating Its Effect on Listening and Speaking Skills

ERIC Educational Resources Information Center

Ashraf, Hamid; Ahmadi, Fatemeh; Hosseinnia, Mansooreh

2017-01-01

The present study intended to integrate some 21st century skills teaching into English classroom and investigate their effect on listening and reading comprehension skills. In so doing, the study used a quantitative, experimental design with 55 participants, 25 in the control group and 30 in the experimental group who were students of second high…

Investigating the Effect of Extensive Reading on EFL Learners' Reading Attitudes at Hail University in KSA

ERIC Educational Resources Information Center

Salameh, Lina Abedelqader Mohmmad

2017-01-01

Extensive reading approach (ER) has received conceptual support from views and theories that prioritize the importance of input in second language acquisition. ER is probably one of the easiest ways to implement an input-rich learning environment in a pedagogical setting. Accordingly, the current study is an attempt to investigate the effect of ER…

Pilot Investigation of the Effectiveness of Respite Care for Carers of an Adult with Mental Illness

ERIC Educational Resources Information Center

Jardim, Claudia; Pakenham, Kenneth I.

2009-01-01

Informal carers of an adult with mental illness have asked that respite care be an integral component of mental health service provision. The present study involved a pilot investigation of the effectiveness of accessing respite care for carers of individuals with a mental illness. It was hypothesised that compared to carers who have not accessed…

Misbehaving Peer Models in the Classroom: An Investigation of the Effects of Social Class and Intelligence.

ERIC Educational Resources Information Center

Kniveton, Bromley H.

1987-01-01

Investigates the effects on young male students of differing social backgrounds and varying levels of intelligence, of seeing a peer misbehave. Notes that working class boys imitated the misbehaving model significantly more than middle-class boys. Level of intelligence was not found to relate to the amount a student imitated a misbehaving peer.…

Investigation of the Effect of Dimple Bionic Nonsmooth Surface on Tire Antihydroplaning.

PubMed

Zhou, Haichao; Wang, Guolin; Ding, Yangmin; Yang, Jian; Zhai, Huihui

2015-01-01

Inspired by the idea that bionic nonsmooth surfaces (BNSS) reduce fluid adhesion and resistance, the effect of dimple bionic nonsmooth structure arranged in tire circumferential grooves surface on antihydroplaning performance was investigated by using Computational Fluid Dynamics (CFD). The physical model of the object (model of dimple bionic nonsmooth surface distribution, hydroplaning model) and SST k - ω turbulence model are established for numerical analysis of tire hydroplaning. By virtue of the orthogonal table L16(4(5)), the parameters of dimple bionic nonsmooth structure design compared to the smooth structure were analyzed, and the priority level of the experimental factors as well as the best combination within the scope of the experiment was obtained. The simulation results show that dimple bionic nonsmooth structure can reduce water flow resistance by disturbing the eddy movement in boundary layers. Then, optimal type of dimple bionic nonsmooth structure is arranged on the bottom of tire circumferential grooves for hydroplaning performance analysis. The results show that the dimple bionic nonsmooth structure effectively decreases the tread hydrodynamic pressure when driving on water film and increases the tire hydroplaning velocity, thus improving tire antihydroplaning performance.

Investigation of the Effect of Dimple Bionic Nonsmooth Surface on Tire Antihydroplaning

PubMed Central

Zhou, Haichao; Wang, Guolin; Ding, Yangmin; Yang, Jian; Zhai, Huihui

2015-01-01

Inspired by the idea that bionic nonsmooth surfaces (BNSS) reduce fluid adhesion and resistance, the effect of dimple bionic nonsmooth structure arranged in tire circumferential grooves surface on antihydroplaning performance was investigated by using Computational Fluid Dynamics (CFD). The physical model of the object (model of dimple bionic nonsmooth surface distribution, hydroplaning model) and SST k − ω turbulence model are established for numerical analysis of tire hydroplaning. By virtue of the orthogonal table L16(45), the parameters of dimple bionic nonsmooth structure design compared to the smooth structure were analyzed, and the priority level of the experimental factors as well as the best combination within the scope of the experiment was obtained. The simulation results show that dimple bionic nonsmooth structure can reduce water flow resistance by disturbing the eddy movement in boundary layers. Then, optimal type of dimple bionic nonsmooth structure is arranged on the bottom of tire circumferential grooves for hydroplaning performance analysis. The results show that the dimple bionic nonsmooth structure effectively decreases the tread hydrodynamic pressure when driving on water film and increases the tire hydroplaning velocity, thus improving tire antihydroplaning performance. PMID:27018311

Thermodynamic Effect of Platinum Addition to beta-NiAl: An Initial Investigation

NASA Technical Reports Server (NTRS)

2005-01-01

An initial investigation was conducted to determine the effect of platinum addition on the activities of aluminum and nickel in beta-NiAl(Pt) over the temperature range 1354 to 1692 K. These measurements were made with a multiple effusion-cell configured mass spectrometer (multi-cell KEMS). The results of this study show that Pt additions act to decreased alpha(Al) and increased the alpha(Ni) in beta-NiAl(Pt) for constant X(sub Ni)/X(sub Al) approx. = 1.13, while at constant X(sub Al) the affect of Pt on Al is greatly reduced. The measured partial enthalpies of mixing indicate Al-atoms have a strong self interaction while Ni- and Pt-atoms in have similar interactions with Al-atoms. Conversely the binding of Ni-atoms in beta-NiAl decreases with Pt addition independent of Al concentration. These initial results prove the technique can be applied to the Ni-Al-Pt system but more activity measurements are required to fully understand the thermodynamics of this system and how Pt additions improved the scaling behavior of nickel-based superalloys. In addition, with the choice of a suitable oxide material for the effusion-cell, the "closed" isothermal nature of the effusion-cell allows the direct investigation of an alloy-oxide equilibrium which resembles the "local-equilibrium" description of the metal-scale interface observed during high temperature oxidation. It is proposed that with an Al(l) + Al2O3(s) experimental reference state together with the route measurement of the relative partial-pressures of Al(g) and Al2O(g) allows the activities of O and Al2O3 to be determined along with the activities of Ni and Al. These measurements provide a direct method of investigating the thermodynamics of the metal-scale interface of a TGO-scale.

Investigation of Neuropsychopharmacological Effects of a Polyherbal Formulation on the Learning and Memory Process in Rats

PubMed Central

Shah, JS; Goyal, RK

2011-01-01

Objective: To investigate the neuropsychopharmacological effect of a polyherbal formulation (PHF) on the learning and memory processes in rats. Materials and Methods: PHF contains Withania somnifera (Ashwagandha), Nardostachys jatamansi (Jatamansi), Rauwolfia serpentina (Sarpagandha), Evolvulus alsinoides (Shankhpushpi), Asparagus racemosus (Shatavari), Emblica officinalis (Amalki), Mucuna pruriens (Kauch bij extract), Hyoscyamus niger (Khurasani Ajmo), Mineral resin (Shilajit), Pearl (Mukta Shukhti Pishti), and coral calcium (Praval pishti). Its effect (500 mg / kg, p.o.) on the learning and memory processes was tested. The activity of PHF on memory acquisition and retention was studied using passive avoidance learning and elevated plus maze model (EPM) in rats. Results: The animals treated with PHF showed a significant decrease in transfer latency as compared to the control group in EPM. PHF also produced significant improvement in passive avoidance acquisition and memory retrieval, as compared to the controls and reduced the latency to reach the shock free zone (SFZ) after 24 hours. Conclusion: The PHF produces significant improvement in passive avoidance acquisition and memory retrieval in rats, which needs further investigation. PMID:21731356

A pilot investigation of the effect of extremely low frequency pulsed electromagnetic fields on humans' heart rate variability.

PubMed

Baldi, Emilio; Baldi, Claudio; Lithgow, Brian J

2007-01-01

The question whether pulsed electromagnetic field (PEMF) can affect the heart rhythm is still controversial. This study investigates the effects on the cardiocirculatory system of ELF-PEMFs. It is a follow-up to an investigation made of the possible therapeutic effect ELF-PEMFs, using a commercially available magneto therapeutic unit, had on soft tissue injury repair in humans. Modulation of heart rate (HR) or heart rate variability (HRV) can be detected from changes in periodicity of the R-R interval and/or from changes in the numbers of heart-beat/min (bpm), however, R-R interval analysis gives only a quantitative insight into HRV. A qualitative understanding of HRV can be obtained considering the power spectral density (PSD) of the R-R intervals Fourier transform. In this study PSD is the investigative tool used, more specifically the low frequency (LF) PSD and high frequency (HF) PSD ratio (LF/HF) which is an indicator of sympatho-vagal balance. To obtain the PSD value, variations of the R-R time intervals were evaluated from a continuously recorded ECG. The results show a HR variation in all the subjects when they are exposed to the same ELF-PEMF. This variation can be detected by observing the change in the sympatho-vagal equilibrium, which is an indicator of modulation of heart activity. Variation of the LF/HF PSD ratio mainly occurs at transition times from exposure to nonexposure, or vice versa. Also of interest are the results obtained during the exposure of one subject to a range of different ELF-PEMFs. This pilot study suggests that a full investigation into the effect of ELF-PEMFs on the cardiovascular system is justified.

An experimental investigation on the effects of freestream turbulence intensity on film cooling effectiveness and heat transfer coefficient for an anti-vortex hole

NASA Astrophysics Data System (ADS)

Hayes, Stephen Andrew

Film cooling is used to thermally protect combustor and turbine components by creating a layer of relatively cooler air than the freestream air to insulate the components from the hot freestream gases. This relatively cooler air is taken from upstream in the high-pressure compressor section at a loss to the engine efficiency, and therefore must be used as effectively as possible. The efficiency gained from increasing the turbine inlet temperature outweighs the loss due to extracting air from the compressor section if the cooling air is used effectively. A novel anti-vortex hole (AVH) geometry has been investigated experimentally through a transient infrared thermography technique to study the film cooling effectiveness and surface convective heat transfer coefficients for varying blowing ratio and freestream turbulence intensity. A major concern with the AVH will be how the secondary jets counteract the main counter rotating vortex (CRV) pair at increased freestream turbulence levels. This is the first experimental facility to study the effects of higher freestream turbulence levels on an AVH geometry. Furthermore, this is the first experimental investigation to report centerline film cooling effectiveness and the convective heat transfer coefficient that had not been reported in prior studies. The AVH geometry is designed with two secondary holes stemming from a main cooling hole; these holes attempt to diffuse the coolant jet and mitigate the vorticity produced by conventional straight holes. This geometry shows improved results at low turbulence intensities compared to conventional straight holes. Three freestream turbulence intensities of 1, 7.5, and 11.7% were investigated at blowing ratios of 0.5, 1.0, 1.5, and 2.0 to form a test matrix of twelve different test conditions. Results showed that the higher freestream turbulence conditions were beneficial in the performance of the AVH. Increasing the blowing ratio at all turbulence levels also improved film

Investigating the quark flavor dependence of the chiral magnetic effect with a multiphase transport model

NASA Astrophysics Data System (ADS)

Huang, Ling; Ma, Chun-Wang; Ma, Guo-Liang

2018-03-01

Because the properties of the QCD phase transition and the chiral magnetic effect (CME) depend on the number of quark flavors (Nf) and quark mass, relativistic heavy-ion collisions provide a natural environment to investigate the flavor features if quark deconfinement occurs. We introduce an initial two-flavor or three-flavor dipole charge separation into a multiphase transport (AMPT) model to investigate the flavor dependence of the CME. By taking advantage of the recent ALICE data of charge azimuthal correlations with identified hadrons, we attempt to disentangle two-flavor and three-flavor CME scenarios in Pb+Pb collisions at 2.76 TeV. We find that the experimental data show a certain potential to distinguish the two scenarios, therefore we further suggest to collect more data to clarify the possible flavor dependence in future experiments.

Inclusiveness, Effectiveness and Intrusiveness: Issues in the Developing Uses of DNA Profiling in Support of Criminal Investigations

PubMed Central

2005-01-01

Précis The rapid implementation and continuing expansion of forensic DNA databases around the world has been supported by claims about their effectiveness in criminal investigations and challenged by assertions of the resulting intrusiveness into individual privacy. These two competing perspectives provide the basis for ongoing considerations about the categories of persons who should be subject to nonconsensual DNA sampling and profile retention as well as the uses to which such profiles should be put. This paper uses the example of the current arrangements for forensic DNA databasing in England & Wales to discuss the ways in which the legislative and operational basis for police DNA databasing is reliant upon continuous deliberations over these and other matters by a range of key stakeholders. We also assess the effects of the recent innovative use of DNA databasing for ‘familial searching’ in this jurisdiction in order to show how agreed understandings about the appropriate uses of DNA can become unsettled and reformulated even where their investigative effectiveness is uncontested. We conclude by making some observations about the future of what is recognised to be the largest forensic DNA database in the world. PMID:16240734

An Investigation of the Compensatory Effectiveness of Assistive Technology on Postsecondary Students with Learning Disabilities. Final Report.

ERIC Educational Resources Information Center

Murphy, Harry; Higgins, Eleanor

This final report describes the activities and accomplishments of a 3-year study on the compensatory effectiveness of three assistive technologies, optical character recognition, speech synthesis, and speech recognition, on postsecondary students (N=140) with learning disabilities. These technologies were investigated relative to: (1) immediate…

In search of the big fish: investigating the coexistence of the big-fish-little-pond effect with the positive effects of upward comparisons.

PubMed

Seaton, Marjorie; Marsh, Herbert W; Dumas, Florence; Huguet, Pascal; Monteil, Jean-Marc; Régner, Isabelle; Blanton, Hart; Buunk, Abraham P; Gibbons, Frederick X; Kuyper, Hans; Suls, Jerry; Wheeler, Ladd

2008-03-01

Blanton, Buunk, Gibbons, and Kuyper (1999) and Huguet, Dumas, Monteil, and Genestoux (2001) found that children nominated a social comparison target who slightly outperformed them in class with a beneficial effect on course grades - an assimilation effect, but with no effects on self-evaluation. However, big-fish-little-pond effect (BFLPE) research has shown that attending a high-ability school has a negative effect on academic self-concept--a contrast effect. To resolve this apparent conflict, the present investigation (1) tested the BFLPE in the Netherlands and France, using nationally representative samples (Study 1) and (2) further analysed (using more sophisticated analyses) the Dutch (Blanton et al.) study (Study 2) and the French (Huguet et al.) study including new French data (Study 3), to examine whether the BFLPE coexisted with, or was moderated by, the beneficial impact of upward comparisons. In support of the BFLPE, all studies found the negative effects of school- or class-average ability on self-evaluation, demonstrating that these assimilation and contrast effects can coexist.

Investigating the Effect of van Hiele Phase-Based Instruction on Pre-Service Teachers' Geometric Thinking

ERIC Educational Resources Information Center

Armah, Robert Benjamin; Cofie, Primrose Otokonor; Okpoti, Christopher Adjei

2018-01-01

This study investigated the effect of van Hiele Phase-based Instruction (VHPI) on Ghanaian Pre-service Teachers' (PTs') geometric thinking in terms of the van Hiele Levels. A pre-test post-test quasi-experimental design was employed. There were 75 PTs each in the experimental group and the control group. Van Hiele Geometry Test (VHGT) was…

Automated Data Processing Support of Investigation and Security Missions at the Defense Investigative Service

DTIC Science & Technology

1990-03-29

This is our final report on the Audit of Automated Data Processing Support of Investigative and Security Missions at the Defense Investigative...Service for your information and use. Comments on a draft of this report were considered in preparing the final report. The audit was made from May through...October 1989. The objectives of the audit were to determine if the Defense Investigative Service (DIS) was effectively managing automated data

Design of a quasi-experiment on the effectiveness and cost-effectiveness of using the child-interview intervention during the investigation following a report of child abuse and/or neglect.

PubMed

Snoeren, Froukje; Hoefnagels, Cees; Lamers-Winkelman, Francien; Baeten, Paul; Evers, Silvia M A A

2013-12-11

In the Netherlands, suspected cases of child maltreatment can be reported to an advice and reporting center on child abuse and neglect (Advies- en Meldpunt Kindermishandeling or AMK). AMKs investigate these reports, screen for problems in the family and its surroundings and refer to child welfare. Over the last decades the focus of AMK investigations has changed from an adult-only approach to a more child-oriented approach using a Child-Interview intervention. The effects and cost-effectiveness of AMK involvement in the Netherlands have never been studied. The primary aim of this study is therefore to examine the effect of the participation of maltreated children aged 6-18 years in the Child-Interview intervention on their mental health and quality of life. As a second aim, this study will examine the balance between additional costs and effects of the Child-Interview intervention in comparison with AMK investigation without the Child-Interview intervention (adult-only intervention). A quasi-experiment will be performed consisting of two post-intervention measurements of two nonequivalent groups: an intervention group, in which the Child-Interview intervention has been used during the AMK investigation, and a control group, in which the intervention has not been used (adult-only intervention). Participants from an ongoing prospective study on the mental health and quality of life of maltreated children after a report to an AMK, will be contacted to complete a questionnaire twice. Multivariate regression analyses will be used to determine effectiveness of the Child-Interview intervention. The economic evaluation will involve a cost-effectiveness analysis and a cost-utility analysis. This will be the first study to examine the effect of AMK involvement in the Netherlands. Using the Child-Interview intervention during AMK investigation may prevent or reduce negative outcomes of child maltreatment, which may result in a lower consumption of healthcare and other

Increased cognitive control after task conflict? Investigating the N-3 effect in task switching.

PubMed

Schuch, Stefanie; Grange, James A

2018-05-25

Task inhibition is considered to facilitate switching to a new task and is assumed to decay slowly over time. Hence, more persisting inhibition needs to be overcome when returning to a task after one intermediary trial (ABA task sequence) than when returning after two or more intermediary trials (CBA task sequence). Schuch and Grange (J Exp Psychol Learn Mem Cogn 41:760-767, 2015) put forward the hypothesis that there is higher task conflict in ABA than CBA sequences, leading to increased cognitive control in the subsequent trial. They provided evidence that performance is better in trials following ABA than following CBA task sequences. Here, this effect of the previous task sequence ("N-3 effect") is further investigated by varying the cue-stimulus interval (CSI), allowing for short (100 ms) or long (900 ms) preparation time for the upcoming task. If increased cognitive control after ABA involves a better preparation for the upcoming task, the N-3 effect should be larger with long than short CSI. The results clearly show that this is not the case. In Experiment 1, the N-3 effect was smaller with long than short CSI; in Experiment 2, the N-3 effect was not affected by CSI. Diffusion model analysis confirmed previous results in the literature (regarding the effect of CSI and of the ABA-CBA difference); however, the N-3 effect was not unequivocally associated with any of the diffusion model parameters. In exploratory analysis, we also tested the alternative hypothesis that the N-3 effect involves more effective task shielding, which would be reflected in reduced congruency effects in trials following ABA, relative to trials following CBA; congruency effects did not differ between these conditions. Taken together, we can rule out two potential explanations of the N-3 effect: Neither is this effect due to enhanced task preparation, nor to more effective task shielding.

Investigation of specimen size effects by in-situ microcompression of equal channel angular pressed copper

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

Howard, C.; Frazer, D.; Lupinacci, A.

Here, micropillar compression testing was implemented on Equal Channel Angular Pressed copper samples ranging from 200 nm to 10 µm in side length in order to measure the mechanical properties yield strength, first load drop during plastic deformation at which there was a subsequent stress decrease with increasing strain, work hardening, and strain hardening exponent. Several micropillars containing multiple grains were investigated in a 200 nm grain sample. The effective pillar diameter to grain size ratios, D/d, were measured to be between 1.9 and 27.2. Specimens having D/d ratios between 0.2 and 5 were investigated in a second sample thatmore » was annealed at 200 °C for 2 h with an average grain size of 1.3 µm. No yield strength or elastic modulus size effects were observed in specimens in the 200 nm grain size sample. However work hardening increases with a decrease in critical ratios and first stress drops occur at much lower stresses for specimens with D/d ratios less than 5. For comparison, bulk tensile testing of both samples was performed, and the yield strength values of all micropillar compression tests for the 200 nm grained sample are in good agreement with the yield strength values of the tensile tests.« less

Investigation of specimen size effects by in-situ microcompression of equal channel angular pressed copper

DOE PAGES

Howard, C.; Frazer, D.; Lupinacci, A.; ...

2015-09-30

Here, micropillar compression testing was implemented on Equal Channel Angular Pressed copper samples ranging from 200 nm to 10 µm in side length in order to measure the mechanical properties yield strength, first load drop during plastic deformation at which there was a subsequent stress decrease with increasing strain, work hardening, and strain hardening exponent. Several micropillars containing multiple grains were investigated in a 200 nm grain sample. The effective pillar diameter to grain size ratios, D/d, were measured to be between 1.9 and 27.2. Specimens having D/d ratios between 0.2 and 5 were investigated in a second sample thatmore » was annealed at 200 °C for 2 h with an average grain size of 1.3 µm. No yield strength or elastic modulus size effects were observed in specimens in the 200 nm grain size sample. However work hardening increases with a decrease in critical ratios and first stress drops occur at much lower stresses for specimens with D/d ratios less than 5. For comparison, bulk tensile testing of both samples was performed, and the yield strength values of all micropillar compression tests for the 200 nm grained sample are in good agreement with the yield strength values of the tensile tests.« less

Wind tunnel investigation of the effect of high relative velocities on the structural integrity of birds

NASA Technical Reports Server (NTRS)

Bresnahan, D. L.

1972-01-01

An experimental investigation was conducted in a supersonic wind tunnel to determine the effect a sudden high velocity headwind had on the physical deformation and structural breakup characteristics of birds. Several sizes of recently killed birds were dropped into the test section at free-stream Mach numbers ranging from 0.2 to 0.8 and photographed with high-speed motion-picture cameras. These conditions simulated flow conditions encountered when birds are ingested into the inlets of high speed aircraft, thereby constituting a safety hazard to the aircraft and its occupants. The investigation shows that, over the range of headwind conditions tested, the birds remained structurally intact and did not suffer any appreciable deformation or structural breakup.

Effect of chlorhexidine digluconate on different cell types: a molecular and ultrastructural investigation.

PubMed

Giannelli, M; Chellini, F; Margheri, M; Tonelli, P; Tani, A

2008-03-01

Although several studies have shown that chlorhexidine digluconate (CHX) has bactericidal activity against periodontal pathogens and exerts toxic effects on periodontal tissues, few have been directed to evaluate the mechanisms underlying its adverse effects on these tissues. Therefore, the aim of the present study was to investigate the in vitro cytotoxicity of CHX on cells that could represent common targets for its action in the surgical procedures for the treatment of periodontitis and peri-implantitis and to elucidate its mechanisms of action. Osteoblastic, endothelial and fibroblastic cell lines were exposed to various concentrations of CHX for different times and assayed for cell viability and cell death. Also analysis of mitochondrial membrane potential, intracellular Ca2+ mobilization and reactive oxygen species (ROS) generation were done in parallel, to correlate CHX-induced cell damage with alterations in key parameters of cell homeostasis. CHX affected cell viability in a dose and time-dependent manners, particularly in osteoblasts. Its toxic effect consisted in the induction of apoptotic and autophagic/necrotic cell deaths and involved disturbance of mitochondrial function, intracellular Ca2+ increase and oxidative stress. These data suggest that CHX is highly cytotoxic in vitro and invite to a more cautioned use of the antiseptic in the oral surgical procedures.

A Practical Science Investigation for Middle School Students: Designing a Simple Cost Effective Chemical Solar Padiation Dosimeter

ERIC Educational Resources Information Center

Downs, Nathan; Larsen, Kim; Parisi, Alfio; Schouten, Peter; Brennan, Chris

2012-01-01

A practical exercise for developing a simple cost-effective solar ultraviolet radiation dosimeter is presented for use by middle school science students. Specifically, this exercise investigates a series of experiments utilising the historical blue print reaction, combining ammonium iron citrate and potassium hexacyanoferrate to develop an…

Cation distributions on rapidly solidified cobalt ferrite

NASA Technical Reports Server (NTRS)

De Guire, Mark R.; Kalonji, Gretchen; O'Handley, Robert C.

1990-01-01

The cation distributions in two rapidly solidified cobalt ferrites have been determined using Moessbauer spectroscopy at 4.2 K in an 8-T magnetic field. The samples were obtained by gas atomization of a Co0-Fe2O3-P2O5 melt. The degree of cation disorder in both cases was greater than is obtainable by cooling unmelted cobalt ferrite. The more rapidly cooled sample exhibited a smaller departure from the equilibrium cation distribution than did the more slowly cooled sample. This result is explained on the basis of two competing effects of rapid solidification: high cooling rate of the solid, and large undercooling.

An empirical investigation of the efficiency effects of integrated care models in Switzerland

PubMed Central

Reich, Oliver; Rapold, Roland; Flatscher-Thöni, Magdalena

2012-01-01

Introduction This study investigates the efficiency gains of integrated care models in Switzerland, since these models are regarded as cost containment options in national social health insurance. These plans generate much lower average health care expenditure than the basic insurance plan. The question is, however, to what extent these total savings are due to the effects of selection and efficiency. Methods The empirical analysis is based on data from 399,274 Swiss residents that constantly had compulsory health insurance with the Helsana Group, the largest health insurer in Switzerland, covering the years 2006–2009. In order to evaluate the efficiency of the different integrated care models, we apply an econometric approach with a mixed-effects model. Results Our estimations indicate that the efficiency effects of integrated care models on health care expenditure are significant. However, the different insurance plans vary, revealing the following efficiency gains per model: contracted capitated model 21.2%, contracted non-capitated model 15.5% and telemedicine model 3.7%. The remaining 8.5%, 5.6% and 22.5%, respectively, of the variation in total health care expenditure can be attributed to the effects of selection. Conclusions Integrated care models have the potential to improve care for patients with chronic diseases and concurrently have a positive impact on health care expenditure. We suggest policy-makers improve the incentives for patients with chronic diseases within the existing regulations providing further potential for cost-efficiency of medical care. PMID:22371691

Investigation of the effects of sleeper-passing impacts on the high-speed train

NASA Astrophysics Data System (ADS)

Wu, Xingwen; Cai, Wubin; Chi, Maoru; Wei, Lai; Shi, Huailong; Zhu, Minhao

2015-12-01

The sleeper-passing impact has always been considered negligible in normal conditions, while the experimental data obtained from a High-speed train in a cold weather expressed significant sleeper-passing impacts on the axle box, bogie frame and car body. Therefore, in this study, a vertical coupled vehicle/track dynamic model was developed to investigate the sleeper-passing impacts and its effects on the dynamic performance of the high-speed train. In the model, the dynamic model of vehicle is established with 10 degrees of freedom. The track model is formulated with two rails supported on the discrete supports through the finite element method. The contact forces between the wheel and rail are estimated using the non-linear Hertz contact theory. The parametric studies are conducted to analyse effects of both the vehicle speeds and the discrete support stiffness on the sleeper-passing impacts. The results show that the sleeper-passing impacts become extremely significant with the increased support stiffness of track, especially when the frequencies of sleeper-passing impacts approach to the resonance frequencies of wheel/track system. The damping of primary suspension can effectively lower the magnitude of impacts in the resonance speed ranges, but has little effect on other speed ranges. Finally, a more comprehensively coupled vehicle/track dynamic model integrating with a flexible wheel set is developed to discuss the sleeper-passing-induced flexible vibration of wheel set.

Numerical investigation of velocity slip and temperature jump effects on unsteady flow over a stretching permeable surface

NASA Astrophysics Data System (ADS)

Hosseini, E.; Loghmani, G. B.; Heydari, M.; Rashidi, M. M.

2017-02-01

In this paper, the boundary layer flow and heat transfer of unsteady flow over a porous accelerating stretching surface in the presence of the velocity slip and temperature jump effects are investigated numerically. A new effective collocation method based on rational Bernstein functions is applied to solve the governing system of nonlinear ordinary differential equations. This method solves the problem on the semi-infinite domain without truncating or transforming it to a finite domain. In addition, the presented method reduces the solution of the problem to the solution of a system of algebraic equations. Graphical and tabular results are presented to investigate the influence of the unsteadiness parameter A , Prandtl number Pr, suction parameter fw, velocity slip parameter γ and thermal slip parameter φ on the velocity and temperature profiles of the fluid. The numerical experiments are reported to show the accuracy and efficiency of the novel proposed computational procedure. Comparisons of present results are made with those obtained by previous works and show excellent agreement.

The Distracting Effects of a Ringing Cell Phone: An Investigation of the Laboratory and the Classroom Setting

PubMed Central

Shelton, Jill T.; Elliott, Emily M.; Lynn, Sharon D.; Exner, Amanda L.

2010-01-01

The detrimental effects of a ringing phone on cognitive performance were investigated in four experiments. In Experiments 1 and 2, the effects of different types of sounds (a standard cell phone ring, irrelevant tones and an instrumental song commonly encountered by participants) on performance were examined. In Experiment 1, slower responses were observed in all auditory groups relative to a silence condition, but participants in the ring and song conditions recovered more slowly. In Experiment 2, participants who were warned about the potential for distraction recovered more quickly, suggesting a benefit of this prior knowledge. This investigation continued in a college classroom setting (Experiments 3a and 3b); students were exposed to a ringing cell phone during the lecture. Performance on a surprise quiz revealed low accuracy rates on material presented while the phone was ringing. These findings offer insight into top-down cognitive processes that moderate involuntary orienting responses associated with a common stimulus encountered in the environment. PMID:21234286

An experimental and analytical investigation of stall effects on flap-lag stability in forward flight

NASA Technical Reports Server (NTRS)

Nagabhushanam, J.; Gaonkar, Gopal H.; Mcnulty, Michael J.

1987-01-01

Experiments have been performed with a 1.62 m diameter hingeless rotor in a wind tunnel to investigate flap-lag stability of isolated rotors in forward flight. The three-bladed rotor model closely approaches the simple theoretical concept of a hingeless rotor as a set of rigid, articulated flap-lag blades with offset and spring restrained flap and lag hinges. Lag regressing mode stability data was obtained for advance ratios as high as 0.55 for various combinations of collective pitch and shaft angle. The prediction includes quasi-steady stall effects on rotor trim and Floquet stability analyses. Correlation between data and prediction is presented and is compared with that of an earlier study based on a linear theory without stall effects. While the results with stall effects show marked differences from the linear theory results, the stall theory still falls short of adequate agreement with the experimental data.

Investigation of the effects of long duration space exposure on active optical system components

NASA Technical Reports Server (NTRS)

Blue, M. D.

1994-01-01

This experiment was exposed to the space environment for 6 years on the Long Duration Exposure Facility (LDEF). It investigated quantitatively the effects of the long-duration space exposure on the relevant performance parameters of a representative set of electron-optic system components, including lasers, radiation detectors, filters, modulators, windows, and other related components. It evaluated the results and implications of the measurements indicating real or suspected degradation mechanisms. This information will be used to establish guidelines for the selection and use of components for space-based, electro-optic systems.

Numerical investigation of effects on blanks for press hardening process during longitudinal flux heating

NASA Astrophysics Data System (ADS)

Dietrich, André; Nacke, Bernard

2018-05-01

With the induction heating technology, it is possible to heat up blanks for the press hardening process in 20 s or less. Furthermore, the dimension of an induction system is small and easy to control in comparison to conventional heating systems. To bring the induction heating technology to warm forming industry it is necessary to analyze the process under the view of induction. This paper investigates the edge- and end-effects of a batch heated blank. The results facilitate the later design of induction heating systems for the batch process.

Investigation of the Specht density estimator

NASA Technical Reports Server (NTRS)

Speed, F. M.; Rydl, L. M.

1971-01-01

The feasibility of using the Specht density estimator function on the IBM 360/44 computer is investigated. Factors such as storage, speed, amount of calculations, size of the smoothing parameter and sample size have an effect on the results. The reliability of the Specht estimator for normal and uniform distributions and the effects of the smoothing parameter and sample size are investigated.

Applying Kalman filtering to investigate tropospheric effects in VLBI

NASA Astrophysics Data System (ADS)

Soja, Benedikt; Nilsson, Tobias; Karbon, Maria; Heinkelmann, Robert; Liu, Li; Lu, Cuixian; Andres Mora-Diaz, Julian; Raposo-Pulido, Virginia; Xu, Minghui; Schuh, Harald

2014-05-01

Very Long Baseline Interferometry (VLBI) currently provides results, e.g., estimates of the tropospheric delays, with a delay of more than two weeks. In the future, with the coming VLBI2010 Global Observing System (VGOS) and increased usage of electronic data transfer, it is planned that the time between observations and results is decreased. This may, for instance, allow the integration of VLBI-derived tropospheric delays into numerical weather prediction models. Therefore, future VLBI analysis software packages need to be able to process the observational data autonomously in near real-time. For this purpose, we have extended the Vienna VLBI Software (VieVS) by a Kalman filter module. This presentation describes the filter and discusses its application for tropospheric studies. Instead of estimating zenith wet delays as piece-wise linear functions in a least-squares adjustment, the Kalman filter allows for more sophisticated stochastic modeling. We start with a random walk process to model the time-dependent behavior of the zenith wet delays. Other possible approaches include the stochastic model described by turbulence theory, e.g. the model by Treuhaft and Lanyi (1987). Different variance-covariance matrices of the prediction error, depending on the time of the year and the geographic latitude, have been tested. In winter and closer to the poles, lower variances and covariances are appropriate. The horizontal variations in tropospheric delays have been investigated by comparing three different strategies: assumption of a horizontally stratified troposphere, using north and south gradients modeled, e.g., as Gauss-Markov processes, and applying a turbulence model assuming correlations between observations in different azimuths. By conducting Monte-Carlo simulations of current standard VLBI networks and of future VGOS networks, the different tropospheric modeling strategies are investigated. For this purpose, we use the simulator module of VieVS which takes into

Effects of an online alcohol education course among college freshmen: an investigation of potential mediators.

PubMed

Paschall, Mallie J; Ringwalt, Chris; Wyatt, Todd; Dejong, William

2014-04-01

The authors investigated possible mediating effects of psychosocial variables (perceived drinking norms, positive and negative alcohol expectancies, personal approval of alcohol use, protective behavioral strategies) targeted by an online alcohol education course (AlcoholEdu for College) as part of a 30-campus randomized trial with 2,400 first-year students. Previous multilevel analyses have found significant effects of the AlcoholEdu course on the frequency of past-30-day alcohol use and binge drinking during the fall semester, and the most common types of alcohol-related problems. Exposure to the online AlcoholEdu course was inversely related to perceived drinking norms but was not related to any of the other psychosocial variables. Multilevel analyses indicated at least partial mediating effects of perceived drinking norms on behavioral outcomes. Findings of this study suggest that AlcoholEdu for College affects alcohol use and related consequences indirectly through its effect on student perceptions of drinking norms. Further research is needed to better understand why this online course did not appear to affect other targeted psychosocial variables.

Human small bowel as a useful tool to investigate smooth muscle effects of potential therapeutics in organophosphate poisoning.

PubMed

Marquart, Katharina; Prokopchuk, Olga; Worek, Franz; Thiermann, Horst; Martignoni, Marc E; Wille, Timo

2018-09-01

Isolated organs proofed to be a robust tool to study effects of (potential) therapeutics in organophosphate poisoning. Small bowel samples have been successfully used to reveal smooth muscle relaxing effects. In the present study, the effects of obidoxime, TMB-4, HI-6 and MB 327 were investigated on human small bowel tissue and compared with rat data. Hereby, the substances were tested in at least seven different concentrations in the jejunum or ileum both pre-contracted with carbamoylcholine. Additionally, the cholinesterase activity of native tissue was determined. Human small intestine specimens showed classical dose response-curves, similar to rat tissue, with MB 327 exerting the most potent smooth muscle relaxant effect in both species (human EC 50 =0.7×10 -5 M and rat EC 50 =0.7×10 -5 M). The AChE activity for human and rat samples did not differ significantly (rat jejunum=1351±166 mU/mg wet weight; rat ileum=1078±123 mU/mg wet weight; human jejunum=1030±258 mU/mg wet weight; human ileum=1293±243 mU/mg wet weight). Summarizing, our isolated small bowel setup seems to be a solid tool to investigate the effects of (potential) therapeutics on pre-contracted smooth muscle, with data being transferable between rat and humans. Copyright © 2017 Elsevier B.V. All rights reserved.

SPM investigation of local aging effects in glassy polymers

NASA Astrophysics Data System (ADS)

Crider, Philip

2005-03-01

We investigate the cooperative and heterogeneous nature of glassy dynamics by nanometer-scale probing in a glassy polymer, Polyvinyl-Actetate (PVAc), with a Scanning Force Microscope (SFM). Using ultra-high-vacuum (UHV) Scanning Capacitive Force Microscopy techniques, nanometer-scale capacitive responses are probed. Dielectric relaxation near the glass transition is investigated, and scanning capabilities are utilized to analyze spatial response on a nanometer scale. The results of these studies may yield insight into the understanding of temperature-dependent cooperative length scales, local aging properties, and energy landscape properties of evolving dipole clusters on a mesoscopic scale. Results are used to test the validity and relevance of current models of glassy dynamics.

An Investigation of the Effectiveness of Increasing Academic Learning Time for College Undergraduate Students' Achievement in Kuwait

ERIC Educational Resources Information Center

Al-Shammari, Zaid; Mohammad, Anwar; Al-Shammari, Bandar

2010-01-01

The study investigated the effectiveness of increasing ALT for college students' achievement in Kuwait. In Phase 1, 37 students participated (22, experimental; 15, control); in Phase 2, 19 students participated (8, sub-experimental; 11, sub-control). Several experimental research methods used in conducting this study, including development of a…

Investigating the Effects of Background Knowledge on Chinese Word Processing during Text Reading: Evidence from Eye Movements

ERIC Educational Resources Information Center

Jian, Yu-Cin; Ko, Hwa-Wei

2014-01-01

This study investigates the effects of background knowledge on Chinese word processing during silent reading by monitoring adult readers' eye movements. Both higher knowledge (physics major) and lower knowledge (nonphysics major) graduate students were given physics texts to read. Higher knowledge readers spent less time rereading and had…

An Investigation of the Life Experiences and Beliefs of High School Teachers Exhibiting Effective Classroom Management Behaviors

ERIC Educational Resources Information Center

Miller, Byron

2012-01-01

The purpose of this qualitative study was to explore the life experiences and beliefs of high school teachers exhibiting highly effective classroom management skills. The research for this phenomenological study utilized the narrative inquiry method of data collection. This study investigates the life experiences and beliefs of nine teachers…

Investigating industrial investigation: examining the impact of a priori knowledge and tunnel vision education.

PubMed

Maclean, Carla L; Brimacombe, C A Elizabeth; Lindsay, D Stephen

2013-12-01

The current study addressed tunnel vision in industrial incident investigation by experimentally testing how a priori information and a human bias (generated via the fundamental attribution error or correspondence bias) affected participants' investigative behavior as well as the effectiveness of a debiasing intervention. Undergraduates and professional investigators engaged in a simulated industrial investigation exercise. We found that participants' judgments were biased by knowledge about the safety history of either a worker or piece of equipment and that a human bias was evident in participants' decision making. However, bias was successfully reduced with "tunnel vision education." Professional investigators demonstrated a greater sophistication in their investigative decision making compared to undergraduates. The similarities and differences between these two populations are discussed. (c) 2013 APA, all rights reserved

Investigation of scale effects in the TRF determined by VLBI

NASA Astrophysics Data System (ADS)

Wahl, Daniel; Heinkelmann, Robert; Schuh, Harald

2017-04-01

-linear motion or completely excluding affected stations is another important step for an improved scale determination. In addition to the investigation of single baseline repeatabilities also the spatial transformation, which is performed for determining parameters of the ITRF2008, are considered. Since the reliability of the resulting transformation parameters is higher the more identical points are used in the transformation, an approach where all possible stations are used as control points is comprehensible. Experiments that examine the scale-factor and its spatial behavior between control points in ITRF2008 and coordinates determined by VLBI only showed that the network geometry has a large influence on the outcome as well. Introducing an unequally distributed network for the datum configuration, the correlations between translation parameters and the scale-factor can become remarkably high. Only a homogeneous spatial distribution of participating stations yields a maximally uncorrelated scale-factor that can be interpreted independent from other parameters. In the current release of the ITRF, the ITRF2014, for the first time, non-linear effects in the time series of station coordinates are taken into account. The present work shows the importance and the right direction of the modification of the ITRF calculation. But also further improvements were found which lead to an enhanced scale determination.

Investigating the effects of PDC cutters geometry on ROP using the Taguchi technique

NASA Astrophysics Data System (ADS)

Jamaludin, A. A.; Mehat, N. M.; Kamaruddin, S.

2017-10-01

At times, the polycrystalline diamond compact (PDC) bit’s performance dropped and affects the rate of penetration (ROP). The objective of this project is to investigate the effect of PDC cutter geometry and optimize them. An intensive study in cutter geometry would further enhance the ROP performance. The relatively extended analysis was carried out and four significant geometry factors have been identified that directly improved the ROP. Cutter size, back rake angle, side rake angle and chamfer angle are the stated geometry factors. An appropriate optimization technique that effectively controls all influential geometry factors during cutters manufacturing is introduced and adopted in this project. By adopting L9 Taguchi OA, simulation experiment is conducted by using explicit dynamics finite element analysis. Through a structure Taguchi analysis, ANOVA confirms that the most significant geometry to improve ROP is cutter size (99.16% percentage contribution). The optimized cutter is expected to drill with high ROP that can reduce the rig time, which in its turn, may reduce the total drilling cost.

INVESTIGATION OF THE HUMIDITY EFFECT ON THE FAC-IR-300 IONIZATION CHAMBER RESPONSE.

PubMed

Mohammadi, Seyed Mostafa; Tavakoli-Anbaran, Hossein

2018-02-01

The free-air ionization chamber is communicating with the ambient air, therefore, the atmospheric parameters such as temperature, pressure and humidity effect on the ionization chamber performance. The free-air ionization chamber, entitled as FAC-IR-300, that design at the Atomic Energy Organization of Iran, AEOI, is required the atmospheric correction factors for correct the chamber reading. In this article, the effect of humidity on the ionization chamber response was investigated. For this reason, was introduced the humidity correction factor, kh. In this article, the Monte Carlo simulation was used to determine the kh factor. The simulation results show in relative humidities between 30% to 80%, the kh factor is equal 0.9970 at 20°C and 0.9975 at 22°C. From the simulation results, at low energy the energy dependence of the kh factor is significant and with increasing energy this dependence is negligible. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Investigating the Effect of Contextual Clues on the Processing of Unfamiliar Words in Second Language Listening Comprehension

ERIC Educational Resources Information Center

Cai, Wei; Lee, Benny P. H.

2010-01-01

This study examines the effect of contextual clues on the use of strategies (inferencing and ignoring) and knowledge sources (semantics, morphology, world knowledge, and others) for processing unfamiliar words in listening comprehension. Three types of words were investigated: words with local co-text clues, global co-text clues and extra-textual…

Total Dose Effects (TDE) of heavy ionizing radiation in fungus spores and plant seeds: Preliminary investigations

NASA Technical Reports Server (NTRS)

Kranz, A. R.; Zimmermann, M. W.; Stadler, R.; Gartenbach, K. E.; Pickert, M.

1992-01-01

The opportunity to compare cosmic radiation effects caused during long and short duration exposure flights in biological objects are limited until now, and data obtained so far are very rare and insufficient. Because of the very long exposure of the experiment during the Long Duration Exposure Facility (LDEF) mission (approximately 2000 days) structural changes of the hardware material can be expected which will influence its biocompatibility and, thus, will interact with the radiobiological effects. The aim of the experiment flown on LDEF was a detailed investigation of biological effects caused by cosmic radiation especially of particles of high atomic number Z and high energy. The flight hardware consisted of standard BIOSTACK containers; in these containers a special sandwich construction consisted of visual plastic detectors with seed rsp. spore layers interlocked.

Kinesthetic Investigations in the Physics Classroom

ERIC Educational Resources Information Center

Whitworth, Brooke A.; Chiu, Jennifer L.; Bell, Randy L.

2014-01-01

Creating investigations that allow students to see physics in their everyday world and to be kinesthetically active outside of the traditional physics classroom can be incredibly engaging and effective. The investigations we developed were inquiry investigations in which students engaged in concrete experiences before we discussed the abstract…

Zeeman effect of weak La I lines investigated by the use of optogalvanic spectroscopy

NASA Astrophysics Data System (ADS)

Sobolewski, Ł. M.; Windholz, L.; Kwela, J.

2017-03-01

New Landé- gJ factors of 35 energy levels of La I, found from investigations of 40 spectral lines in the wavelength range 562.959÷609.537 nm, were determined. As a source of free La atoms a hollow cathode discharge lamp was used. We monitored the signal of the optogalvanic effect appearing when a laser beam is passing through the hollow cathode. Spectra were recorded in the presence of a magnetic field of about 800 G produced by a permanent magnet, for two linear polarizations of the exciting laser light. Optogalvanic spectroscopy is a very sensitive method, so we were able to observe the Zeeman effect of very weak atomic lines. In this way we have determined for the first time the Landé-gJ factors for 35 recently found levels of neutral La. The Landé gJ- factors for several other levels were reinvestigated.

Effective Boundary Conditions for Continuum Method of Investigation of Rarefied Gas Flow over Blunt Body

NASA Astrophysics Data System (ADS)

Brykina, I. G.; Rogov, B. V.; Semenov, I. L.; Tirskiy, G. A.

2011-05-01

Super- and hypersonic rarefied gas flow over blunt bodies is investigated by using asymptotically correct viscous shock layer (VSL) model with effective boundary conditions and thin viscous shock layer model. Correct shock and wall conditions for VSL are proposed with taking into account terms due to the curvature which are significant at low Reynolds number. These conditions improve original Davis's VSL model [1]. Numerical calculation of Krook equation [2] is carried out to verify continuum results. Continuum numerical and asymptotic solutions are compared with kinetic solution, free-molecule flow solution and with DSMC solutions [3, 4, 5] over a wide range of free-stream Knudsen number Kn∞. It is shown that taking into account terms with shock and surface curvatures have a pronounced effect on skin friction and heat-transfer in transitional flow regime. Using the asymptotically correct VSL model with effective boundary conditions significantly extends the range of its applicability to higher Kn∞ numbers.

Effects of the 2017 Solar Eclipse on HF Radio Propagation and the D-Region Ionosphere: Citizen Science Investigation

NASA Astrophysics Data System (ADS)

Fry, C. D.; Adams, M.; Gallagher, D. L.; Habash Krause, L.; Rawlins, L.; Suggs, R. M.; Anderson, S. C.

2017-12-01

August 21, 2017 provided a unique opportunity to investigate the effects of the total solar eclipse on high frequency (HF) radio propagation and ionospheric variability. In Marshall Space Flight Center's partnership with the US Space and Rocket Center (USSRC) and Austin Peay State University (APSU), we engaged students and citizen scientists in an investigation of the eclipse effects on the mid-latitude ionosphere. The Amateur Radio community has developed several automated receiving and reporting networks that draw from widely-distributed, automated and manual radio stations to build a near-real time, global picture of changing radio propagation conditions. We used these networks and employed HF radio propagation modeling in our investigation. A Ham Radio Science Citizen Investigation (HamSCI) collaboration with the American Radio Relay League (ARRL) ensured that many thousands of amateur radio operators would be "on the air" communicating on eclipse day, promising an extremely large quantity of data would be collected. Activities included implementing and configuring software, monitoring the HF Amateur Radio frequency bands and collecting radio transmission data on days before, the day of, and days after the eclipse to build a continuous record of changing propagation conditions as the moon's shadow marched across the United States. Our expectations were the D-Region ionosphere would be most impacted by the eclipse, enabling over-the-horizon radio propagation on lower HF frequencies (3.5 and 7 MHz) that are typically closed during the middle of the day. Post-eclipse radio propagation analysis provided insights into ionospheric variability due to the eclipse. We report on results, interpretation, and conclusions of these investigations.

Acute effects of cocaine and cannabis on response inhibition in humans: an ERP investigation.

PubMed

Spronk, Desirée B; De Bruijn, Ellen R A; van Wel, Janelle H P; Ramaekers, Johannes G; Verkes, Robbert J

2016-11-01

Substance abuse has often been associated with alterations in response inhibition in humans. Not much research has examined how the acute effects of drugs modify the neurophysiological correlates of response inhibition, or how these effects interact with individual variation in trait levels of impulsivity and novelty seeking. This study investigated the effects of cocaine and cannabis on behavioural and event-related potential (ERP) correlates of response inhibition in 38 healthy drug using volunteers. A double-blind placebo-controlled randomized three-way crossover design was used. All subjects completed a standard Go/NoGo task after administration of the drugs. Compared with a placebo, cocaine yielded improved accuracy, quicker reaction times and an increased prefrontal NoGo-P3 ERP. Cannabis produced opposing results; slower reaction times, impaired accuracy and a reduction in the amplitude of the prefrontal NoGo-P3. Cannabis in addition decreased the amplitude of the parietally recorded P3, while cocaine did not affect this. Neither drugs specifically affected the N2 component, suggesting that pre-motor response inhibitory processes remain unaffected. Neither trait impulsivity nor novelty seeking interacted with drug-induced effects on measures of response inhibition. We conclude that acute drug effects on response inhibition seem to be specific to the later, evaluative stages of response inhibition. The acute effects of cannabis appeared less specific to response inhibition than those of cocaine. Together, the results show that the behavioural effects on response inhibition are reflected in electrophysiological correlates. This study did not support a substantial role of vulnerability personality traits in the acute intoxication stage. © 2015 Society for the Study of Addiction.

An Investigation of the Effects of Reader Characteristics on Reading Comprehension Of a General Chemistry Text

NASA Astrophysics Data System (ADS)

Neiles, Kelly Y.

There is great concern in the scientific community that students in the United States, when compared with other countries, are falling behind in their scientific achievement. Increasing students' reading comprehension of scientific text may be one of the components involved in students' science achievement. To investigate students' reading comprehension this quantitative study examined the effects of different reader characteristics, namely, students' logical reasoning ability, factual chemistry knowledge, working memory capacity, and schema of the chemistry concepts, on reading comprehension of a chemistry text. Students' reading comprehension was measured through their ability to encode the text, access the meanings of words (lexical access), make bridging and elaborative inferences, and integrate the text with their existing schemas to make a lasting mental representation of the text (situational model). Students completed a series of tasks that measured the reader characteristic and reading comprehension variables. Some of the variables were measured using new technologies and software to investigate different cognitive processes. These technologies and software included eye tracking to investigate students' lexical accessing and a Pathfinder program to investigate students' schema of the chemistry concepts. The results from this study were analyzed using canonical correlation and regression analysis. The canonical correlation analysis allows for the ten variables described previously to be included in one multivariate analysis. Results indicate that the relationship between the reader characteristic variables and the reading comprehension variables is significant. The resulting canonical function accounts for a greater amount of variance in students' responses then any individual variable. Regression analysis was used to further investigate which reader characteristic variables accounted for the differences in students' responses for each reading comprehension

[Preliminary investigation of the in vitro inhibitory effect of antibiotics on algae of the genus Prototheca].

PubMed

Casal, M; Gutierrez, J

1981-07-10

We investigated the possible inhibitory action 'in vitro' by antibiotic containing discs against microscopic alga that are potential human pathogens of the genus Prototheca especially P. wickerhamii. The results indicated that inhibitors in vitro included amikacin, colistin, dibecacin, framicetin, gentamycin, kanamycin, lividomycin, neomycin, polymyxin, paromomycin, ribostamycin, sisomycin and tobramycin. We emphasize the interest in the effectiveness at these drugs in a case of human protothecosis.

Investigating physical field effects on the size-dependent dynamic behavior of inhomogeneous nanoscale plates

NASA Astrophysics Data System (ADS)

Ebrahimi, Farzad; Reza Barati, Mohammad

2017-02-01

This article investigates the thermo-mechanical vibration frequencies of magneto-electro-thermo-elastic functionally graded (METE-FG) nanoplates in the framework of refined four-unknown shear deformation plate theory. The present nanoplate is subjected to various kinds of thermal loads with uniform, linear and nonlinear distributions. The nonlinear distribution is considered as heat conduction and sinusoidal temperature rise. The present refined theory captures the influences of shear deformations without the need for shear correction factors. Thermo-magneto-electro-elastic coefficients of the FG nanoplate vary gradually along the thickness according to the power-law form. The scale coefficient is taken into consideration implementing the nonlocal elasticity of Eringen. The governing equations are derived through Hamilton's principle and are solved analytically. The frequency response is compared with those of previously published data. The obtained results are presented for the thermo-mechanical vibrations of the FG nanobeams to investigate the effects of material graduation, nonlocal parameter, mode number, slenderness ratio and thermal loading in detail. The present study is associated to aerospace, mechanical and nuclear engineering structures which are under thermal loads.

Effect of emodin on Candida albicans growth investigated by microcalorimetry combined with chemometric analysis.

PubMed

Kong, W J; Wang, J B; Jin, C; Zhao, Y L; Dai, C M; Xiao, X H; Li, Z L

2009-07-01

Using the 3114/3115 thermal activity monitor (TAM) air isothermal microcalorimeter, ampoule mode, the heat output of Candida albicans growth at 37 degrees C was measured, and the effect of emodin on C. albicans growth was evaluated by microcalorimetry coupled with chemometric methods. The similarities between the heat flow power (HFP)-time curves of C. albicans growth affected by different concentrations of emodin were calculated by similarity analysis (SA). In the correspondence analysis (CA) diagram of eight quantitative parameters taken from the HFP-time curves, it could be deduced that emodin had definite dose-effect relationship as the distance between different concentrations of it increased along with the dosage and the effect. From the principal component analysis (PCA) on eight quantitative parameters, the action of emodin on C. albicans growth could be easily evaluated by analyzing the change of values of the main two parameters, growth rate constant k (2) and maximum power output P(2)(m). The coherent results of SA, CA, and PCA showed that emodin at different concentrations had different effects on C. albicans growth metabolism: A low concentration (0-10 microg ml(-1)) poorly inhibited the growth of C. albicans, and a high concentration (15-35 microg ml(-1)) could notably inhibit growth of this fungus. This work provided a useful idea of the combination of microcalorimetry and chemometric analysis for investigating the effect of drug and other compounds on microbes.

Investigation of the phototoxic effect of ZnO nanorods on fibroblasts and melanoma human cells

NASA Astrophysics Data System (ADS)

Kishwar, S.; Siddique, M.; Israr-Qadir, M.; Nur, O.; Willander, M.; Öllinger, K.

2014-11-01

Photocytotoxic effects of as-grown and zinc oxide (ZnO) nanorods coated with 5-aminolevulinic acid (ALA) have been studied on human cells, i.e. melanoma and foreskin fibroblast, under dark and ultraviolet light exposures. Zinc oxide nanorods have been grown on the very sharp tip (diameter = 700 nm) of borosilicate glass pipettes and then were coated by the photosensitizer for targeted investigations inside human cells. The coated glass pipette’s tip with photosensitizer has been inserted inside the cells with the help of a micro-manipulator and irradiated through ultraviolet light (UVA), which reduces the membrane potential of the mitochondria leading to cell death. Cell viability loss has been detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay when exposed to the dissolved ZnO nanorods and the production of the reactive oxygen species (ROS) has been detected along with the enhanced cytotoxic effect under UVA irradiation. Additionally, the influence of the lipid soluble antioxidant vitamin E and water-soluble N-acetyl-cysteine toward the enhancement or reduction of the toxicity has been investigated. A comparative analysis of the toxic nature of ZnO nanorods has been drawn between normal human fibroblast and melanoma cells, which can be favorable for understanding the clinical setting for killing tumor cells.

An investigation of the time course of category congruence and priming distance effects in number classification tasks.

PubMed

Perry, Jason R; Lupker, Stephen J

2012-09-01

The issue investigated in the present research is the nature of the information that is responsible for producing masked priming effects (e.g., semantic information or stimulus-response [S-R] associations) when responding to number stimuli. This issue was addressed by assessing both the magnitude of the category congruence (priming) effect and the nature of the priming distance effect across trials using single-digit primes and targets. Participants made either magnitude (i.e., whether the number presented was larger or smaller than 5) or identification (i.e., press the left button if the number was either a 1, 2, 3, or 4 or the right button if the number was either a 6, 7, 8, or 9) judgments. The results indicated that, regardless of task instruction, there was a clear priming distance effect and a significantly increasing category congruence effect. These results indicated that both semantic activation and S-R associations play important roles in producing masked priming effects.

Investigation of nitrogen transport in active screen plasma nitriding processes - Uphill diffusion effect

NASA Astrophysics Data System (ADS)

Jasinski, J. J.; Fraczek, T.; Kurpaska, L.; Lubas, M.; Sitarz, M.

2018-07-01

The paper presents a structure of a nitrided layer formed with active screen plasma nitriding (ASPN) technique, which is a modification of plasma nitriding. The model investigated material was Fe Armco. The nitriding processes were carried out at 773 K for 6 h and 150 Pa. The main objective of this study was to confirm nitrogen migration effect and its influence on the nitride layer formation in different area of the layer interfaces (ε/ε+γ‧/γ‧). The results of the tests were evaluated using scanning electron microscopy (SEM, SEM/EBSD), transmission electron microscopy - electron energy loss spectroscopy (TEM-EFTEM), secondary ion mass spectroscopy (SIMS) and Wavelength Dispersive X-Ray Spectrometry (WDS). The analysis of the results suggests that the structures of the nitrided layers and nitrides morphology differ for various parameters and are dependent on the surface layer saturation mechanism for each of the temperatures and process parameters. New approaches in diffusion of nitrogen and carbon atoms and optimizing process were also analyzed. Nitrogen and also carbon transport in the sublayer was observed by several effects i.e. uphill diffusion effect which confirmed migration of the atoms in diffusive layer towards top surface (ε/ε+γ‧ interface) and stress change effect in the nitrogen saturation area of the (Fe(C,N)+γ‧) layer. Results showed in the paper might be used both for optimization of ASPN processes, modeling of nitrided layers formation mechanism and for controlling the nitrided layers morphology when nitriding different Fe based materials.

Free compressible jet investigation

NASA Astrophysics Data System (ADS)

De Gregorio, Fabrizio

2014-03-01

The nozzle pressure ratio (NPR) effect on a supersonic turbulent jet was investigated. A dedicated convergent/divergent nozzle together with a flow feeding system was designed and manufactured. A nozzle Mach exit of M j = 1.5 was selected in order to obtain a convective Mach number of M c = 0.6. The flow was investigated for over-expanded, correctly expanded and under-expanded jet conditions. Mach number, total temperature and flow velocity measurements were carried out in order to characterise the jet behaviour. The inlet conditions of the jet flow were monitored in order to calculate the nozzle exit speed of sound and evaluate the mean Mach number distribution starting from the flow velocity data. A detailed analysis of the Mach results obtained by a static Pitot probe and by a particle image velocimetry measurement system was carried out. The mean flow velocity was investigated, and the axial Mach decay and the spreading rate were associated with the flow structures and with the compressibility effects. Aerodynamics of the different jet conditions was evaluated, and the shock cells structures were detected and discussed correlating the jet structure to the flow fluctuation and local turbulence. The longitudinal and radial distribution of the total temperature was investigated, and the temperature profiles were analysed and discussed. The total temperature behaviour was correlated to the turbulent phenomena and to the NPR jet conditions. Self-similarity condition was encountered and discussed for the over-expanded jet. Compressibility effects on the local turbulence, on the turbulent kinetic energy and on the Reynolds tensor were discussed.

A piloted simulation of helicopter air combat to investigate effects of variations in selected performance and control response characteristics

NASA Technical Reports Server (NTRS)

Lewis, Michael S.; Mansur, M. Hossein; Chen, Robert T. N.

1987-01-01

A piloted simulation study investigating handling qualities and flight characteristics required for helicopter air to air combat is presented. The Helicopter Air Combat system was used to investigate this role for Army rotorcraft. Experimental variables were the maneuver envelope size (load factor and sideslip), directional axis handling qualities, and pitch and roll control-response type. Over 450 simulated, low altitude, one-on-one engagements were conducted. Results from the experiment indicate that a well damped directional response, low sideforce caused by sideslip, and some effective dihedral are all desirable for weapon system performance, good handling qualities, and low pilot workload. An angular rate command system was favored over the attitude type pitch and roll response for most applications, and an enhanced maneuver envelope size over that of current generation aircraft was found to be advantageous. Pilot technique, background, and experience are additional factors which had a significant effect on performance in the air combat tasks investigated. The implication of these results on design requirements for future helicopters is presented.

Investigation of bioactivity and cell effects of nano-porous sol-gel derived bioactive glass film

NASA Astrophysics Data System (ADS)

Ma, Zhijun; Ji, Huijiao; Hu, Xiaomeng; Teng, Yu; Zhao, Guiyun; Mo, Lijuan; Zhao, Xiaoli; Chen, Weibo; Qiu, Jianrong; Zhang, Ming

2013-11-01

In orthopedic surgery, bioactive glass film coating is extensively studied to improve the synthetic performance of orthopedic implants. A lot of investigations have confirmed that nano-porous structure in bioactive glasses can remarkably improve their bioactivity. Nevertheless, researches on preparation of nano-porous bioactive glasses in the form of film coating and their cell response activities are scarce. Herein, we report the preparation of nano-porous bioactive glass film on commercial glass slide based on a sol-gel technique, together with the evaluation of its in vitro bioactivity through immersion in simulated body fluid and monitoring the precipitation of apatite-like layer. Cell responses of the samples, including attachment, proliferation and osteogenic differentiation, were also investigated using BMSCS (bone marrow derived mesenchymal stem cells) as a model. The results presented here provide some basic information on structural influence of bioactive glass film on the improvement of bioactivity and cellular effects.

Lattice density functional theory investigation of pore shape effects. I. Adsorption in single nonperiodic pores.

PubMed

Malanoski, A P; van Swol, Frank

2002-10-01

A fully explicit in three dimensions lattice density functional theory is used to investigate adsorption in single nonperiodic pores. The effect of varying pore shape from the slits and cylinders that are normally simulated was our primary interest. A secondary concern was the results for pores with very large diameters. The shapes investigated were square pores with or without surface roughness, cylinders, right triangle pores, and trapezoidal pores. It was found that pores with very similar shape factors gave similar results but that the introduction of acute angled corners or very large side ratio lengths in rectangular pores gave results that were significantly different. Further, a rectangular pore going towards the limit of infinite side ratio does not approach the results of a slit pore. In all of these cases, the importance of features that are present for only a small portion of the pore is demonstrated.

An Investigation of Magneto-Optical Effects

NASA Technical Reports Server (NTRS)

Adams, Mitzi L.; Hagyard, Mona J.; West, Edward A.

1998-01-01

We exhibit the effects of Faraday rotation on the direction of the transverse component of the magnetic field in a simple, symmetric sunspot. A set of 35 polarization filtergrams of NOAA active region 4662 (June 9, 1985) were obtained with the Marshall Space Flight Center (MSFC) vector magnetograph. These filtergrams measured the Stokes I, Q, U, and V intensities averaged over the instrument's filter bandpass (0.0125 nm) for wavelengths from 0.017 nm in the red wing to 0.017 nm in the blue wing of the Lambda525.22 nm spectral line in steps of 0.001 nm. These data were used to derive the azimuth phi of the vector field as a function of wavelength over the field of view of the sunspot. We interpret the observed variations of this azimuth with wavelength as the effects of Faraday rotation and verify this interpretation by comparing these variations with those predicted from magneto-optical theory. In the theoretical calculations we use the line-profile parameters and magnetic field strength derived in previous work by Balasubramaniam and West (Astrophys. J 382, p. 699, 1991).

Computational Investigation of the Aerodynamic Effects on Fluidic Thrust Vectoring

NASA Technical Reports Server (NTRS)

Deere, K. A.

2000-01-01

A computational investigation of the aerodynamic effects on fluidic thrust vectoring has been conducted. Three-dimensional simulations of a two-dimensional, convergent-divergent (2DCD) nozzle with fluidic injection for pitch vector control were run with the computational fluid dynamics code PAB using turbulence closure and linear Reynolds stress modeling. Simulations were computed with static freestream conditions (M=0.05) and at Mach numbers from M=0.3 to 1.2, with scheduled nozzle pressure ratios (from 3.6 to 7.2) and secondary to primary total pressure ratios of p(sub t,s)/p(sub t,p)=0.6 and 1.0. Results indicate that the freestream flow decreases vectoring performance and thrust efficiency compared with static (wind-off) conditions. The aerodynamic penalty to thrust vector angle ranged from 1.5 degrees at a nozzle pressure ratio of 6 with M=0.9 freestream conditions to 2.9 degrees at a nozzle pressure ratio of 5.2 with M=0.7 freestream conditions, compared to the same nozzle pressure ratios with static freestream conditions. The aerodynamic penalty to thrust ratio decreased from 4 percent to 0.8 percent as nozzle pressure ratio increased from 3.6 to 7.2. As expected, the freestream flow had little influence on discharge coefficient.

Investigations on birefringence effects in polymer optical fiber Bragg gratings

NASA Astrophysics Data System (ADS)

Hu, X.; Sáez-Rodríguez, D.; Bang, O.; Webb, D. J.; Caucheteur, C.

2014-05-01

Step-index polymer optical fiber Bragg gratings (POFBGs) and microstructured polymer optical fiber Bragg gratings (mPOFBGs) present several attractive features, especially for sensing purposes. In comparison to FBGs written in silica fibers, they are more sensitive to temperature and pressure because of the larger thermo-optic coefficient and smaller Young's modulus of polymer materials. (M)POFBGs are most often photowritten in poly(methylmethacrylate) (PMMA) materials using a continuous-wave 325 nm HeCd laser. For the first time to the best of our knowledge, we study photoinduced birefringence effects in (m)POFBGs. To achieve this, highly reflective gratings were inscribed with the phase mask technique. They were then monitored in transmission with polarized light. For this, (m)POF sections a few cm in length containing the gratings were glued to angled silica fibers. Polarization dependent loss (PDL) and differential group delay (DGD) were computed from the Jones matrix eigenanalysis using an optical vector analyser. Maximum values exceeding several dB and a few picoseconds were obtained for the PDL and DGD, respectively. The response to lateral force was finally investigated. As it induces birefringence in addition to the photo-induced one, an increase of the PDL and DGD values were noticed.

Numerical and Experimental Investigation of the Effects of Acceleration Disturbances on Microgravity Experiments

NASA Technical Reports Server (NTRS)

Ramachandran, Narayanan

2000-01-01

Normal vibrational modes on large spacecraft are excited by crew activity, operating machinery, and other mechanical disturbances. Periodic engine burns for maintaining vehicle attitude and random impulse type disturbances also contribute to the acceleration environment of a Spacecraft. Accelerations from these vibrations (often referred to as g-jitter) are several orders of magnitude larger than the residual accelerations from atmospheric drag and gravity gradient effects. Naturally, the effects of such accelerations have been a concern to prospective experimenters wishing to take advantage of the microgravity environment offered by spacecraft operating in low Earth orbit and the topic has been studied extensively, both numerically and analytically. However, these studies have not produced a general theory that predicts the effects of multi-spectral periodic accelerations on a general class of experiments nor have they produced scaling laws that a prospective experimenter could use to assess how his/her experiment might be affected by this acceleration environment. Furthermore, there are no actual flight experimental data that correlates heat or mass transport with measurements of the periodic acceleration environment. The present investigation approaches this problem with carefully conducted terrestrial experiments and rigorous numerical modeling thereby providing comparative theoretical and experimental data. The modeling, it is hoped will provide a predictive tool that can be used for assessing experiment response to Spacecraft vibrations.

Eyewitness identification in simultaneous and sequential lineups: an investigation of position effects using receiver operating characteristics.

PubMed

Meisters, Julia; Diedenhofen, Birk; Musch, Jochen

2018-04-20

For decades, sequential lineups have been considered superior to simultaneous lineups in the context of eyewitness identification. However, most of the research leading to this conclusion was based on the analysis of diagnosticity ratios that do not control for the respondent's response criterion. Recent research based on the analysis of ROC curves has found either equal discriminability for sequential and simultaneous lineups, or higher discriminability for simultaneous lineups. Some evidence for potential position effects and for criterion shifts in sequential lineups has also been reported. Using ROC curve analysis, we investigated the effects of the suspect's position on discriminability and response criteria in both simultaneous and sequential lineups. We found that sequential lineups suffered from an unwanted position effect. Respondents employed a strict criterion for the earliest lineup positions, and shifted to a more liberal criterion for later positions. No position effects and no criterion shifts were observed in simultaneous lineups. This result suggests that sequential lineups are not superior to simultaneous lineups, and may give rise to unwanted position effects that have to be considered when conducting police lineups.

Gamma ray irradiated silicon nanowires: An effective model to investigate defects at the interface of Si/SiOx

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

Yin, Kui; Zhao, Yi; Liu, Liangbin

2014-01-20

The effect of gamma ray irradiation on silicon nanowires was investigated. Here, an additional defect emerged in the gamma-ray-irradiated silicon nanowires and was confirmed with electron spin resonance spectra. {sup 29}Si nuclear magnetic resonance spectroscopy showed that irradiation doses had influence on the Q{sup 4} unit structure. This phenomenon indicated that the unique core/shell structure of silicon nanowires might contribute to induce metastable defects under gamma ray irradiation, which served as a satisfactory model to investigate defects at the interface of Si/SiOx.

LASERS IN MEDICINE: Investigation of the influence of the photodynamic effect on micro-organisms using the laser photothermal cytometry method

NASA Astrophysics Data System (ADS)

Lapotko, D. O.; Zharov, V. P.; Romanovskaya, T. R.; Kuchinskii, G. S.

1999-12-01

An investigation of the influence of the photodynamic effect on S.aureus and E.coli bacteria in the presence of blood cells was made by the laser photothermal cytometry method. Elements of the theory of the photothermal method are considered for the case of pulsed lasers used in microscopy. Chlorin in doses of 0.02 mg litre-1 was used as a photosensitiser. The results of the investigation made it possible to propose the possibility of an immunomodulation effect caused by introducing photoactivated chlorin into the cell — microbe system. It was found that the photothermal parameters of the cells interacting with microbes in the presence of photoactivated chlorin differed from the parameters of intact cells much less than in the absence of chlorin. However, a more pronounced bactericidal effect was observed in the samples treated with chlorin.

The Investigation Of Carbon Contamination And Sputtering Effects Of Xenon Ion Thrusters

NASA Technical Reports Server (NTRS)

Prak, Moline K.

2004-01-01

The Electro-Physics Branch of the NASA Glenn Research Center investigates the effect of atomic oxygen, environmental durability of high performance power materials and surfaces, and low earth orbit. One of its current projects involves the analysis of ion thrusters. Ion thrusters are devices that initiate a beam of ions to a target area. The type of ion thruster that I have been working with this Summer of 2004 emits positively charged Xenon (Xe(+)) atoms through two grids, the screen grid and the accelerator grid, after it enters an ionization chamber. Insulators are used to mechanically hold and separate these two grids. A propellant isolator, an instrument that closely resembles insulators, is placed in front of the ionization chamber. Both the insulator and isolator are made with a ceramic compound and filled with insulating beads. The main difference between the two devices is that the propellant isolator allows gas to flow through, in this case, the gas is Xe(+) and the insulators do not. In order to avoid carbon deposits and other contaminating chemicals to settle on the insulators and propellant isolator, a metal shadow shield is placed around them. These shadow shields function as a protectant and can be shaped in numerous configurations. Part of my job responsibility this summer is to investigate the effectiveness of different shadow shields that are utilized on three different ion engines: the NSTAR (NASA Solar Electric Propulsion Technology Application Readiness), JIMO (Jupiter Icy Moons Orbiter), and NEXIS (Nuclear Electric Xenon Ion System). Using calculus and other mathematical tactics, I was asked to find the total flux of carbon contamination that was able to pass the protectant shadow shield. I familiarized myself with the software program, MathCad2004, to help perform some mathematical computations such as complex integration. Another method of studying the probability of contamination is by experimental simulation. After attaining the precise

Numerical investigation of shape domain effect to its elasticity and surface energy using adaptive finite element method

NASA Astrophysics Data System (ADS)

Alfat, Sayahdin; Kimura, Masato; Firihu, Muhammad Zamrun; Rahmat

2018-05-01

In engineering area, investigation of shape effect in elastic materials was very important. It can lead changing elasticity and surface energy, and also increase of crack propagation in the material. A two-dimensional mathematical model was developed to investigation of elasticity and surface energy in elastic material by Adaptive Finite Element Method. Besides that, behavior of crack propagation has observed for every those materials. The government equations were based on a phase field approach in crack propagation model that developed by Takaishi-Kimura. This research has varied four shape domains where physical properties of materials were same (Young's modulus E = 70 GPa and Poisson's ratio ν = 0.334). Investigation assumptions were; (1) homogeneous and isotropic material, (2) there was not initial cracking at t = 0, (3) initial displacement was zero [u1, u2] = 0) at initial condition (t = 0), and (4) length of time simulation t = 5 with interval Δt = 0.005. Mode I/II or mixed mode crack propagation has been used for the numerical investigation. Results of this studies were very good and accurate to show changing energy and behavior of crack propagation. In the future time, this research can be developed to complex phenomena and domain. Furthermore, shape optimization can be investigation by the model.

Investigation of aerosol indirect effects on simulated flash-flood heavy rainfall over Korea

NASA Astrophysics Data System (ADS)

Lim, Kyo-Sun Sunny; Hong, Song-You

2012-11-01

This study investigates aerosol indirect effects on the development of heavy rainfall near Seoul, South Korea, on 12 July 2006, focusing on precipitation amount. The impact of the aerosol concentration on simulated precipitation is evaluated by varying the initial cloud condensation nuclei (CCN) number concentration in the Weather Research and Forecasting (WRF) Double-Moment 6-class (WDM6) microphysics scheme. The simulations are performed under clean, semi-polluted, and polluted conditions. Detailed analysis of the physical processes that are responsible for surface precipitation, including moisture and cloud microphysical budgets shows enhanced ice-phase processes to be the primary driver of increased surface precipitation under the semi-polluted condition. Under the polluted condition, suppressed auto-conversion and the enhanced evaporation of rain cause surface precipitation to decrease. To investigate the role of environmental conditions on precipitation response under different aerosol number concentrations, a set of sensitivity experiments are conducted with a 5 % decrease in relative humidity at the initial time, relative to the base simulations. Results show ice-phase processes having small sensitivity to CCN number concentration, compared with the base simulations. Surface precipitation responds differently to CCN number concentration under the lower humidity initial condition, being greatest under the clean condition, followed by the semi-polluted and polluted conditions.

Experimental investigation on performance of crossflow wind turbine as effect of blades number

NASA Astrophysics Data System (ADS)

Kurniawati, Diniar Mungil; Tjahjana, Dominicus Danardono Dwi Prija; Santoso, Budi

2018-02-01

Urban living is one of the areas with large electrical power consumption that requires a power supply that is more than rural areas. The number of multi-storey buildings such as offices, hotels and several other buildings that caused electricity power consumption in urban living is very high. Therefore, energy alternative is needed to replace the electricity power consumption from government. One of the utilization of renewable energy in accordance with these conditions is the installation of wind turbines. One type of wind turbine that is now widely studied is a crossflow wind turbines. Crossflow wind turbine is one of vertical axis wind turbine which has good self starting at low wind speed condition. Therefore, the turbine design parameter is necessary to know in order to improve turbine performance. One of wind turbine performance parameter is blades number. The main purpose of this research to investigate the effect of blades number on crossflow wind turbine performance. The design of turbine was 0.4 × 0.4 m2 tested by experimental method with configuration on three kinds of blades number were 8,16 and 20. The turbine investigated at low wind speed on 2 - 5 m/s. The result showed that best performance on 16 blade number.

Investigation on the effect of nonlinear processes on similarity law in high-pressure argon discharges

NASA Astrophysics Data System (ADS)

Fu, Yangyang; Parsey, Guy M.; Verboncoeur, John P.; Christlieb, Andrew J.

2017-11-01

In this paper, the effect of nonlinear processes (such as three-body collisions and stepwise ionizations) on the similarity law in high-pressure argon discharges has been studied by the use of the Kinetic Global Model framework. In the discharge model, the ground state argon atoms (Ar), electrons (e), atom ions (Ar+), molecular ions (Ar2+), and fourteen argon excited levels Ar*(4s and 4p) are considered. The steady-state electron and ion densities are obtained with nonlinear processes included and excluded in the designed models, respectively. It is found that in similar gas gaps, keeping the product of gas pressure and linear dimension unchanged, with the nonlinear processes included, the normalized density relations deviate from the similarity relations gradually as the scale-up factor decreases. Without the nonlinear processes, the parameter relations are in good agreement with the similarity law predictions. Furthermore, the pressure and the dimension effects are also investigated separately with and without the nonlinear processes. It is shown that the gas pressure effect on the results is less obvious than the dimension effect. Without the nonlinear processes, the pressure and the dimension effects could be estimated from one to the other based on the similarity relations.

77 FR 39101 - Rules Relating to Investigations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-29

... procedures for investigations under section 1052 of the Dodd-Frank Act. DATES: The final rule is effective... Federal consumer financial law. Section 1052 of the Dodd-Frank Act sets forth the parameters that govern these investigations. 12 U.S.C. 5562. Section 1052 became effective immediately upon transfer on July 21...

Investigating the Effect of Cooperative Learning and Competitive Learning Strategies on the English Vocabulary Development of Iranian Intermediate EFL Learners

ERIC Educational Resources Information Center

Fekri, Neda

2016-01-01

The current study investigated the effect of cooperative and competitive learning strategies on the acquisition of English vocabulary development by Iranian EFL intermediate learners. In addition, it explored what type of theses strategies was more effective. In such doing, utilizing an Oxford Placement Test (OPT), 45 out of 77 Iranian EFL…

An Investigation of the Hypoalgesic Effects of TENS Delivered by a Glove Electrode

PubMed Central

Cowan, Stephen; McKenna, Joanne; McCrum-Gardner, Evie; Johnson, Mark I.; Sluka, Kathleen A.; Walsh, Deirdre M.

2009-01-01

This randomized, placebo-controlled, blinded study investigated the hypoalgesic effects of high-frequency transcutaneous electrical nerve stimulation (TENS) delivered via a glove electrode compared with standard self-adhesive electrodes. Fifty-six TENS-naïve, healthy individuals (18 to 50 years old; 28 men, 28 women) were randomly allocated to 1 of 4 groups (n = 14 per group): glove electrode; placebo TENS using a glove electrode; standard electrode; and no treatment control. Active TENS (continuous stimulus, 100 Hz, strong but comfortable intensity) was applied to the dominant forearm/hand for 30 minutes. Placebo TENS was applied using a burst stimulus, 100-Hz frequency, 5-second cycle time for 42 seconds, after which the current amplitude was automatically reset to 0 mA. Pressure pain thresholds (PPTs) were recorded from 3 points on the dominant and nondominant upper limbs before and after TENS. Statistical analyses of dominant PPT data using between-within groups ANOVA showed significant differences between groups at all 3 recording points (P = .01). Post hoc Scheffe tests indicated no significant difference between the standard electrode and glove electrode groups. There was a significant hypoalgesic effect in the standard electrode group compared with the control group and between the glove electrode group and both the control and placebo TENS groups. There was no significant interactive effect between time and group at any of the recording points (P > .05). Perspective This study presents a comparison of the hypoalgesic effects of 2 different types of TENS electrode, a novel glove electrode and standard self-adhesive rectangular electrodes. The glove electrode provides a larger contact area with the skin, thereby stimulating a greater number of nerve fibers. The results show that both electrodes have similar hypoalgesic effects and therefore give the clinician another choice in electrode. PMID:19398378

Investigation of potential endocrine disrupting effects of mosquito larvicidal Bacillus thuringiensis israelensis (Bti) formulations.

PubMed

Maletz, Sibylle; Wollenweber, Marc; Kubiak, Katharina; Müller, Annett; Schmitz, Stefan; Maier, Dieter; Hecker, Markus; Hollert, Henner

2015-12-01

Bti is successfully used as a biological control agent for mosquito control. It has proven to be ecological friendly, and thus, is used in ecologically sensitive habitats. Recent investigations of groundwater in Germany have detected estrogenic activity in five consecutive groundwater wells in a region where Bti is applied. Therefore, it was suspected that this compound can act as an environmental xenoestrogen. In the present study, five Bti formulations as well as the active ingredient, VectoBac® TP (TP), were investigated regarding their estrogenic activity using the LYES and ER CALUX® assays. Furthermore, their steroidogenesis disruption properties were studied using the H295R Steroidogenesis Assay. Additionally, field samples from a Bti application area as well as samples from an artificial pond were examined. Three of the Bti formulations and the active ingredient TP showed significant estrogenic activity in the LYES (up to 52 ng·l(-1) estradiol equivalents (EEQ) in the 18-fold concentration) and/or the ER CALUX® (up to 1 ng·EEQ·l(-1) in the 18-fold concentration). In the H295R significant but weak effects with no dose-response-relationship on the production of estradiol, and 21-hydroxyprogesterone (WDG) as well as testosterone (TP) by H295R cells could be observed. The field samples as well as the samples from the artificial pond showed no significant increase of estrogenic activity after application of TP or WDG in the ER CALUX®. With the exception of the controlled laboratory experiments with direct application of Bti to the utilized in vitro test systems the present study did not reveal any significant effects of Bti on endocrine functions that would indicate that the application of Bti could cause adverse endocrine effects to organisms in aquatic ecosystems. Instead, our results support previous studies that the use of Bti products against mosquitos would be safe even for sensitive habitats such as conservation areas. Copyright © 2015 Elsevier B

An experimental study to investigate the effects of a motion tracking electromagnetic sensor during EEG data acquisition.

PubMed

Bashashati, Ali; Noureddin, Borna; Ward, Rabab K; Lawrence, Peter D; Birch, Gary E

2006-03-01

A power spectral analysis study was conducted to investigate the effects of using an electromagnetic motion tracking sensor on an electroencephalogram (EEG) recording system. The results showed that the sensors do not generate any consistent frequency component(s) in the power spectrum of the EEG in the frequencies of interest (0.1-55 Hz).

Field investigation of influenza vaccine effectiveness on morbidity.

PubMed

Carrat, F; Tachet, A; Rouzioux, C; Housset, B; Valleron, A J

1998-01-01

Our objective was to evaluate influenza vaccine effectiveness during an influenza epidemic by means of a matched case-control study. The study was performed by 35 general practitioners who collected specimens for influenza virus testing from 610 patients who consulted for infectious syndrome: 168 (28%) were influenza-positive. Two designs were used for selecting controls to take into account the high incidence-rate of influenza-like illness and the various possible protective effects of the vaccine. A first disease-free control matched for age and sex was selected during the same week as the case. A second control matched for age and sex was selected at the end of the epidemic period, irrespective of disease history during the epidemic period. Upper and lower bounds of vaccine effectiveness can be derived from these case-control designs. After adjustment for chronic conditions and exposure to an index case, analysis of the matched-pairs whose case was influenza-positive showed, with the first group of controls, an influenza vaccine effectiveness of 68% (95% CI, 10% to 88%) and, in the second group, 53% (95% CI, -19% to 82%). Among the pairs whose case was negative for influenza, vaccine effectiveness was, respectively, 31% (95% CI, -17% to 59%) and 12% (95% CI, -47% to 47%). Vaccine effectiveness was highest for the H3N2 subtype whose vaccine strain was identical to that of the wild-type strain. The results suggest that influenza vaccine is effective in the field in preventing influenza morbidity.

Technique of investigations of thermomagnetic Nernst-Ettingshausen and Maggi-Righi-Leduc effects in micro-samples at ultrahigh pressure

NASA Astrophysics Data System (ADS)

Ovsyannikov, Sergey; Shchennikov, Vladimir

2004-03-01

In the present work the novel technique of investigation of thermomagnetic effects (longitudinal and transverse Nernst-Ettingshausen effects, Maggi-Righi-Leduc effects) on semiconductor micro-samples at high pressure up to 30 GPa has been developed. The technique has been applied for characterisation of semiconductor micro-samples and minerals of VI, IV-VI, and II-VI Groups. Advantages of thermomagnetic effects over the traditional galvanomagnetic ones have been demonstrated. It has been shown that technique of thermomagnetic measurements at high pressure is a powerful tool in studying of parameters of electron structure of semiconductors and being the perspective one for any technological applications. The work was supported by the Russian Foundation for Basic Research, Gr. No. 01-02-17203.

Investigation of the spin Seebeck effect and anomalous Nernst effect in a bulk carbon material

NASA Astrophysics Data System (ADS)

Wongjom, Poramed; Pinitsoontorn, Supree

2018-03-01

Since the discovery of the spin Seebeck effect (SSE) in 2008, it has become one of the most active topics in the spin caloritronics research field. It opened up a new way to create the spin current by a combination of magnetic fields and heat. The SSE was observed in many kinds of materials including metallic, semiconductor, or insulating magnets, as well as non-magnetic materials. On the other hand, carbon-based materials have become one of the most exciting research areas recently due to its low cost, abundance and some exceptional functionalities. In this work, we have investigated the possibility of the SSE in bulk carbon materials for the first time. Thin platinum film (Pt), coated on the smoothened surface of the bulk carbon, was used as the spin detector via the inverse spin Hall effect (ISHE). The experiment for observing longitudinal SSE in the bulk carbon was set up by applying a magnetic field up to 30 kOe to the sample with the direction perpendicular to the applied temperature gradient. The induced voltage from the SSE was extracted. However, for conductive materials, e.g. carbon, the voltage signal under this set up could be a combination of the SSE and the anomalous Nernst effect (ANE). Therefore, two measurement configurations were carried out, i.e. the in-plane magnetization (IM), and the perpendicular-to-plane magnetization (PM). For the IM configuration, the SSE + ANE signals were detected where as the only ANE signal existed in the PM configuration. The results showed that there were the differences between the voltage signals from the IM and PM configurations implying the possibility of the SSE in the bulk carbon material. Moreover, it was found that the difference in the IM and PM signals was a function of the magnetic field strength, temperature difference, and measurement temperature. Although the magnitude of the possible SSE voltage in this experiment was rather low (less than 0.5 μV at 50 K), this research showed that potential of using

Investigating the effectiveness of response strategies for vulnerabilities to corruption in the chinese public construction sector.

PubMed

Shan, Ming; Chan, Albert P C; Le, Yun; Hu, Yi

2015-06-01

Response strategy is a key for preventing widespread corruption vulnerabilities in the public construction sector. Although several studies have been devoted to this area, the effectiveness of response strategies has seldom been evaluated in China. This study aims to fill this gap by investigating the effectiveness of response strategies for corruption vulnerabilities through a survey in the Chinese public construction sector. Survey data obtained from selected experts involved in the Chinese public construction sector were analyzed by factor analysis and partial least squares-structural equation modeling. Analysis results showed that four response strategies of leadership, rules and regulations, training, and sanctions, only achieved an acceptable level in preventing corruption vulnerabilities in the Chinese public construction sector. This study contributes to knowledge by improving the understanding of the effectiveness of response strategies for corruption vulnerabilities in the public construction sector of developing countries.

Investigating the effectiveness of using Bluetooth low-energy technology to trigger in-vehicle messages in work zones : final report.

DOT National Transportation Integrated Search

2016-12-01

In order to reduce risky behavior around workzones, this project examines the effectiveness of using in-vehicle : messages to heighten drivers awareness of safety-critical and pertinent workzone information. : This investigation centers around an ...

Investigation of flaw geometry and loading effects on plane strain fracture in metallic structures

NASA Technical Reports Server (NTRS)

Hall, L. R.; Finger, R. W.

1971-01-01

The effects on fracture and flaw growth of weld-induced residual stresses, combined bending and tension stresses, and stress fields adjacent to circular holes in 2219-T87 aluminum and 5AI-2.5Sn(ELI) titanium alloys were evaluated. Static fracture tests were conducted in liquid nitrogen; fatigue tests were performed in room air, liquid nitrogen, and liquid hydrogen. Evaluation of results was based on linear elastic fracture mechanics concepts and was directed to improving existing methods of estimating minimum fracture strength and fatigue lives for pressurized structure in spacecraft and booster systems. Effects of specimen design in plane-strain fracture toughness testing were investigated. Four different specimen types were tested in room air, liquid nitrogen and liquid hydrogen environments using the aluminum and titanium alloys. Interferometry and holograph were used to measure crack-opening displacements in surface-flawed plexiglass test specimens. Comparisons were made between stress intensities calculated using displacement measurements, and approximate analytical solutions.

Piloted simulator investigation of helicopter control systems effects on handling qualities during instrument flight

NASA Technical Reports Server (NTRS)

Forrest, R. D.; Chen, R. T. N.; Gerdes, R. M.; Alderete, T. S.; Gee, D. R.

1979-01-01

An exploratory piloted simulation was conducted to investigate the effects of the characteristics of helicopter flight control systems on instrument flight handling qualities. This joint FAA/NASA study was motivated by the need to improve instrument flight capability. A near-term objective is to assist in updating the airworthiness criteria for helicopter instrument flight. The experiment consisted of variations of single-rotor helicopter types and levels of stability and control augmentation systems (SCAS). These configurations were evaluated during an omnirange approach task under visual and instrument flight conditions. The levels of SCAS design included a simple rate damping system, collective decoupling plus rate damping, and an attitude command system with collective decoupling. A limited evaluation of stick force versus airspeed stability was accomplished. Some problems were experienced with control system mechanization which had a detrimental effect on longitudinal stability. Pilot ratings, pilot commentary, and performance data related to the task are presented.

A Study Investigating the Effect of Treatment Developed by Integrating the 5E and Simulation on Pre-Service Science Teachers' Achievement in Photoelectric Effect

ERIC Educational Resources Information Center

Taslidere, Erdal

2015-01-01

The Current study investigated the effect of the 5E learning cycle in which the simulations were integrated on pre-service science teachers' achievement in photoelectric subject. Four sophomore level classes with their 140 students participated in the research and a quasi-experimental design was used. The classes were randomly assigned into one of…

The Effect of Two Different Cooperative Approaches on Students' Learning and Practices within the Context of a WebQuest Science Investigation

ERIC Educational Resources Information Center

Zacharia, Zacharias C.; Xenofontos, Nikoletta A.; Manoli, Constantinos C.

2011-01-01

The goal of this study was to investigate the effect of two different cooperative learning approaches, namely, the Jigsaw Cooperative Approach (JCA) and the Traditional Cooperative Approach (TCA), on students' learning and practices/actions within the context of a WebQuest science investigation. Another goal of this study was to identify possible…

Extraction and phytochemical investigation of Calotropis procera: effect of plant extracts on the activity of diverse muscles.

PubMed

Moustafa, A M Y; Ahmed, S H; Nabil, Z I; Hussein, A A; Omran, M A

2010-10-01

Calotropis procera (Ait.) R.Br. (Asclepiadaceae) is a shrub or small tree that grows wild in Egypt. Calotropis acts as a purgative, anthelmintic, anticoagulant, palliative (in problems with respiration, blood pressure), antipyretic, and analgesic, and induces neuromuscular blocking activity. Little research has been done to study the electrophysiological effects of this plant's extracts on cardiac, smooth, and skeletal muscle activities. The present study was conducted to determine the phytochemical composition and the effect of the total alcohol extract of the shoot of the plant, which contains almost all of C. procera's cardiac glycosides, flavonoids, and saponins. Also, this study attempted to throw more light on the electrophysiological effects of the plant extracts on cardiac, smooth, and skeletal muscle activities and to clarify the mechanism(s) of their observed action(s). The aerial parts of the plant were air dried and their ethanol extracts partitioned with successive solvents. Cardiac, smooth, and skeletal muscles were used in this study to investigate the physiological and pharmacological effects of the plant extracts from different solvents. The data were analyzed by paired t-test. The phytochemical investigation of Calotropis procera revealed the presence of cardenolides, flavonoids, and saponins. The effects of ethanol, n-butanol, and ethyl acetate (EtOAc) extracts were each evaluated on isolated toad heart and their mechanisms of action determined. Perfusion with 2 μg/mL ethanol, 0.2 μg/mL butanol, and 0.2 μg/mL EtOAc extracts caused a significant decrease in heart rate (bradycardia), significant increase in the force of ventricular contraction, and increase in T-wave amplitude. In addition, the effects of different extracts of the studied plant on smooth muscle and skeletal muscle were investigated in this study. The different extracts and latex of C. procera induced a negative chronotropic effect and decreased the heart rate (HR) of

Investigating the Effectiveness of Teaching Methods Based on a Four-Step Constructivist Strategy

NASA Astrophysics Data System (ADS)

Çalik, Muammer; Ayas, Alipaşa; Coll, Richard K.

2010-02-01

This paper reports on an investigation of the effectiveness an intervention using several different methods for teaching solution chemistry. The teaching strategy comprised a four-step approach derived from a constructivist view of learning. A sample consisting of 44 students (18 boys and 26 girls) was selected purposively from two different Grade 9 classes in the city of Trabzon, Turkey. Data collection employed a purpose-designed `solution chemistry concept test', consisting of 17 items, with the quantitative data from the survey supported by qualitative interview data. The findings suggest that using different methods embedded within the four-step constructivist-based teaching strategy enables students to refute some alternative conceptions, but does not completely eliminate student alternative conceptions for solution chemistry.

Investigating the Effectiveness of Storylines Embedded within a Context-Based Approach: The Case for the Periodic Table

ERIC Educational Resources Information Center

Demircioglu, Hulya; Demircioglu, Gokhan; Calik, Muammar

2009-01-01

We investigated the effect of the context-based approach on 9th grade students' conceptions of the Periodic Table. Within a nonequivalent pretest-posttest control group design the study was conducted with 80 grade 9 students (aged 15-16) drawn from two classes (39 and 41 students) in a high school in Turkey. The experimental group was exposed to…

Investigating investigators: examining witnesses' influence on investigators.

PubMed

Dahl, Leora C; Lindsay, D Stephen; Brimacombe, C A Elizabeth

2006-12-01

This research examined the influence of eyewitness identification decisions on participants in the role of police investigators. Undergraduate "investigators" interviewed confederate "witnesses" and then searched a computer database of potential suspects. The database included information on each suspect's physical description, prior criminal record, alibi, and fingerprints. Participants selected a suspect and estimated the probability that the suspect was guilty. Investigators subsequently administered a photo lineup to the witness and re-estimated the suspect's guilt. If the witness identified the suspect probability estimates increased dramatically. If the witness identified an innocent lineup member or rejected the lineup, investigators' probability estimates dropped significantly, even when pre-lineup objective evidence (e.g., fingerprints) was strong. Performance of participants acting as witnesses in two baseline studies was at chance. Therefore, participant-investigators greatly overestimated the amount of information gain provided by eyewitness identifications.

Investigation of the safety effects of knee bolster air bag deployment in similar real-world crash comparisons.

PubMed

Weaver, Ashley A; Loftis, Kathryn L; Stitzel, Joel D

2013-01-01

The lower extremity is the most frequently injured body region and knee-thigh-hip (KTH) injuries account for half of these injuries. Knee bolster air bags (KBABs) have been incorporated in some vehicles to serve as an additional restraint for the occupant's knees and reduce KTH injuries. To investigate the safety benefits of KBABs, similar frontal crashes with opposing KBAB deployment were selected from the Crash Injury Research and Engineering Network (CIREN) database. An 8-point similarity scoring algorithm was used to quantify crash and occupant similarity and select case comparisons. A total of 183 cases without a KBAB were scored for similarity to 9 KBAB cases. These similarity scores were used to select 31 final case comparisons. The effect of KBAB deployment on occupant injury patterns was investigated with a particular focus on KTH injuries. Over half of the occupants exposed to a KBAB sustained no KTH injuries and a reduction in femur fractures was observed in KBAB occupants (P = .036). However, increases in proximal tibia/fibula and foot/ankle fractures were observed in KBAB occupants (P = .022 and .002, respectively). Mildly significant decreases in pelvic fractures and Abbreviated Injury Scale (AIS) 2+ head injuries were observed in the KBAB occupants, supporting the notion that KBABs reduce forward occupant excursion (P = .094 and .055, respectively). Investigation of each case comparison yielded further insight into the reasons for injury pattern differences between cases with opposing KBAB deployment. In addition to KBAB deployment status, differences in occupant factors (age, height, and weight) and crash factors (delta V and belt use) between the cases for a particular comparison could explain variation in injury patterns. The current study presents a preliminary in-depth qualitative and quantitative assessment of KBAB safety benefits. However, further investigation is recommended to provide conclusive evidence of KBAB effectiveness.

An investigation of safety belt usage and effectiveness

DOT National Transportation Integrated Search

1975-03-01

This interim report contains primarily a theoretical discussion of problems of inference in studies on seat belt utilization and effectiveness. Seat belt effectiveness in accidents is initially discussed from a population paramenter point of, view. T...

Investigating the Effects of Peer to Peer Prompts on Collaborative Argumentation, Consensus and Perceived Efficacy in Collaborative Learning

ERIC Educational Resources Information Center

Harney, Owen M.; Hogan, Michael J.; Quinn, Sarah

2017-01-01

In a society which is calling for more productive modes of collaboration to address increasingly complex scientific and social issues, greater involvement of students in dialogue, and increased emphasis on collaborative discourse and argumentation, become essential modes of engagement and learning. This paper investigates the effects of…

Cognitive fallacies and criminal investigations.

PubMed

Ditrich, Hans

2015-03-01

The human mind is susceptible to inherent fallacies that often hamper fully rational action. Many such misconceptions have an evolutionary background and are thus difficult to avert. Deficits in the reliability of eye-witnesses are well known to legal professionals; however, less attention has been paid to such effects in crime investigators. In order to obtain an "inside view" on the role of cognitive misconceptions in criminalistic work, a list of fallacies from the literature was adapted to criminalistic settings. The statements on this list were rated by highly experienced crime scene investigators according to the assumed likelihood of these errors to appear and their severity of effect. Among others, selective perception, expectation and confirmation bias, anchoring/"pars per toto" errors and "onus probandi"--shifting the burden of proof from the investigator to the suspect--were frequently considered to negatively affect criminal investigations. As a consequence, the following measures are proposed: alerting investigating officers in their training to cognitive fallacies and promoting the exchange of experiences in peer circles of investigators on a regular basis. Furthermore, the improvement of the organizational error culture and the establishment of a failure analysis system in order to identify and alleviate error prone processes are suggested. Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

Maximization of beta-galactosidase production: a simultaneous investigation of agitation and aeration effects.

PubMed

Alves, Fernanda Germano; Filho, Francisco Maugeri; de Medeiros Burkert, Janaína Fernandes; Kalil, Susana Juliano

2010-03-01

In this work, the agitation and aeration effects in the maximization of the beta-galactosidase production from Kluyveromyces marxianus CCT 7082 were investigated simultaneously, in relation to the volumetric enzyme activity and the productivity, as well as the analysis of the lactose consumption and production of glucose, and galactose of this process. Agitation and aeration effects were studied in a 2 L batch stirred reactor. A central composite design (2(2) trials plus three central points) was carried out. Agitation speed varied from 200 to 500 rpm and aeration rate from 0.5 to 1.5 vvm. It has been shown in this study that the volumetric enzyme production was strongly influenced by mixing conditions, while aeration was shown to be less significant. Linear models for activity and productivity due to agitation and aeration were obtained. The favorable condition was 500 rpm and 1.5 vvm, which lead to the best production of 17 U mL(-1) for enzymatic activity, 1.2 U mL(-1) h(-1) for productivity in 14 h of process, a cellular concentration of 11 mg mL(-1), and a 167.2 h(-1) volumetric oxygen transfer coefficient.

Investigating genetic correlations and causal effects between caffeine consumption and sleep behaviours.

PubMed

Treur, Jorien L; Gibson, Mark; Taylor, Amy E; Rogers, Peter J; Munafò, Marcus R

2018-04-22

Observationally, higher caffeine consumption is associated with poorer sleep and insomnia. We investigated whether these associations are a result of shared genetic risk factors and/or (possibly bidirectional) causal effects. Summary-level data were available from genome-wide association studies on caffeine intake (n = 91 462), plasma caffeine and caffeine metabolic rate (n = 9876), sleep duration and chronotype (being a "morning" versus an "evening" person) (n = 128 266), and insomnia complaints (n = 113 006). First, genetic correlations were calculated, reflecting the extent to which genetic variants influencing caffeine consumption and those influencing sleep overlap. Next, causal effects were estimated with bidirectional, two-sample Mendelian randomization. This approach utilizes the genetic variants most robustly associated with an exposure variable as an "instrument" to test causal effects. Estimates from individual variants were combined using inverse-variance weighted meta-analysis, weighted median regression and MR-Egger regression. We found no clear evidence for a genetic correlation between caffeine intake and sleep duration (rg = 0.000, p = .998), chronotype (rg = 0.086, p = .192) or insomnia complaints (rg = -0.034, p = .700). For plasma caffeine and caffeine metabolic rate, genetic correlations could not be calculated because of the small sample size. Mendelian randomization did not support causal effects of caffeine intake on sleep, or vice versa. There was weak evidence that higher plasma caffeine levels causally decrease the odds of being a morning person. Although caffeine may acutely affect sleep when taken shortly before bedtime, our findings suggest that a sustained pattern of high caffeine consumption is more likely to be associated with poorer sleep through shared environmental factors. Future research should identify such environments, which could aid the development of interventions to improve sleep. © 2018 The

The Investigation of the Cox-2 Selective Inhibitor Parecoxib Effects in Spinal Cord Injury in Rat.

PubMed

Yuksel, Ulas; Bakar, Bulent; Dincel, Gungor Cagdas; Budak Yildiran, Fatma Azize; Ogden, Mustafa; Kisa, Ucler

2018-01-22

Today, spinal cord injury (SCI) can be rehabilitated but cannot be treated adequately. This experimental study was conducted to investigate possible beneficial effects of methylprednisolone and parecoxib in treatment of SCI. Forty-eight male Wistar albino rats were assigned into CONTROL, acute (MP-A, PX-A, and PXMP-A), and subacute (MP-S, PX-S, and PXMP-S) stage groups. Then, to induce SCI, a temporary aneurysm clip was applied to the spinal cord following T7-8 laminectomy, except in the CONTROL group. Four hours later parecoxib, methylprednisolone, or their combination was administered to rats intraperitoneally except CONTROL, SHAM-A, and SHAM-S groups. Rats in the acute stage group were sacrificed 72 h later, and whereas rats in the subacute stage were sacrificed 7 days later for histopathological and biochemical investigation and for gene-expression analyses. Parecoxib and methylprednisolone and their combination could not improve histopathological grades in any stage. They also could not decrease malondialdehyde or caspase-3, myeloperoxidase levels in any stage. Parecoxib and methylprednisolone could decrease the TNF-α gene expression in subacute stage. Methylprednisolone could increase TGF-1β gene-expression level in acute stage. Neither of the experimental drugs, either alone or in combination, did not show any beneficial effects in SCI model in rats.

Martensitic phase transformations in the nanostructured surface layers induced by mechanical attrition treatment

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

Ni Zhichun; Wang Xiaowei; Wu Erdong

2005-12-01

Conversion electron Moessbauer spectroscopy (CEMS) and x-ray diffraction (XRD) analysis have been used to investigate the relationship between characteristics of phase transformation and the treatment time in surface nanocrystallized 316L stainless steel induced by surface mechanical attrition treatment (SMAT). A similar trend of development of the martensitic phase upon the treatment time has been observed from both CEMS and XRD measurements. However, in the CEMS measurement, two types of martensite phase with different magnetic hyperfine fields are revealed. Based on a random distribution of the non-iron coordinating atoms, a three-element theoretical model is developed to illustrate the difference of twomore » types of martensite phase. The calculated results indicate the segregation of the non-iron atoms associated with SMAT treatment.« less

Moessbauer Study of Reduced Putidaredoxin in Zero and Intermediate Applied Fields.

NASA Astrophysics Data System (ADS)

Valentine, Mark

An ('57)Fe Mossbauer investigation of the reduced (S = 1/2) active center of the redox and effector protein, putidaredoxin, is reported. Putidaredoxin is a prototype of a 2Fe-2S protein; it functions as an electron shuttle in a bacterial enzyme system. Several 2Fe-2S proteins, including putidaredoxin, have already been subjected to numerous Mossbauer and magnetic resonance studies, but current understanding of the active center is still very incomplete, and the mechanism of electron transfer is not known. Previous Mossbauer experiments on reduced putidaredoxin, as on most Kramers systems, were restricted to the applied field range .01 - 4T. The intermediate field region 0 - .01T is included here, and a primary goal of this work is to demonstrate the feasibility of those experiments. The analysis of zero field spectra differs from that in applied fields in the following respects: (i) The spectra consist of 64 discrete lines. (ii) The average over all molecular orientations is done explicitly, not numerically. (iii) No generality is lost by taking the magnetic hyperfine terms for both sites to be symmetric and in their principal axis systems. (iv) The spectra are sensitive to weak coupling of S with nearby nuclear moments that become negligible as the applied field is increased. Skew-symmetric contributions to the magnetic hyperfine and electronic Zeeman interactions are often ignored in the literature without justification. Either g or A can be symmetrized by an S transformation, but both g and A can be simultaneously symmetrized if and only if the invariants. (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI). are equal.

A numerical investigation of the effects of the spanwise length on the 3-D wake of a circular cylinder

NASA Astrophysics Data System (ADS)

Labbé, D. F. L.; Wilson, P. A.

2007-11-01

The numerical prediction of vortex-induced vibrations has been the focus of numerous investigations to date using tools such as computational fluid dynamics. In particular, the flow around a circular cylinder has raised much attention as it is present in critical engineering problems such as marine cables or risers. Limitations due to the computational cost imposed by the solution of a large number of equations have resulted in the study of mostly 2-D flows with only a few exceptions. The discrepancies found between experimental data and 2-D numerical simulations suggested that 3-D instabilities occurred in the wake of the cylinder that affect substantially the characteristics of the flow. The few 3-D numerical solutions available in the literature confirmed such a hypothesis. In the present investigation the effect of the spanwise extension of the solution domain on the 3-D wake of a circular cylinder is investigated for various Reynolds numbers between 40 and 1000. By assessing the minimum spanwise extension required to predict accurately the flow around a circular cylinder, the infinitely long cylinder is reduced to a finite length cylinder, thus making numerical solution an effective way of investigating flows around circular cylinders. Results are presented for three different spanwise extensions, namely πD/2, πD and 2πD. The analysis of the force coefficients obtained for the various Reynolds numbers together with a visualization of the three-dimensionalities in the wake of the cylinder allowed for a comparison between the effects of the three spanwise extensions. Furthermore, by showing the different modes of vortex shedding present in the wake and by analysing the streamwise components of the vorticity, it was possible to estimate the spanwise wavelengths at the various Reynolds numbers and to demonstrate that a finite spanwise extension is sufficient to accurately predict the flow past an infinitely long circular cylinder.

Investigation of ionospheric effects on SAR Interferometry (InSAR): A case study of Hong Kong

NASA Astrophysics Data System (ADS)

Zhu, Wu; Ding, Xiao-Li; Jung, Hyung-Sup; Zhang, Qin; Zhang, Bo-Chen; Qu, Wei

2016-08-01

Synthetic Aperture Radar Interferometry (InSAR) has demonstrated its potential for high-density spatial mapping of ground displacement associated with earthquakes, volcanoes, and other geologic processes. However, this technique may be affected by the ionosphere, which can result in the distortions of Synthetic Aperture Radar (SAR) images, phases, and polarization. Moreover, ionospheric effect has become and is becoming further significant with the increasing interest in low-frequency SAR systems, limiting the further development of InSAR technique. Although some research has been carried out, thorough analysis of ionospheric influence on true SAR imagery is still limited. Based on this background, this study performs a thorough investigation of ionospheric effect on InSAR through processing L-band ALOS-1/PALSAR-1 images and dual-frequency Global Positioning System (GPS) data over Hong Kong, where the phenomenon of ionospheric irregularities often occurs. The result shows that the small-scale ionospheric irregularities can cause the azimuth pixel shifts and phase advance errors on interferograms. Meanwhile, it is found that these two effects result in the stripe-shaped features in InSAR images. The direction of the stripe-shaped effects keep approximately constant in space for our InSAR dataset. Moreover, the GPS-derived rate of total electron content change index (ROTI), an index to reflect the level of ionospheric disturbances, may be a useful indicator for predicting the ionospheric effect for SAR images. This finding can help us evaluate the quality of SAR images when considering the ionospheric effect.

Investigating the sonophoresis effect on the permeation of diclofenac sodium using 3D skin equivalent.

PubMed

Aldwaikat, Mai; Alarjah, Mohammed

2015-01-01

Ultrasound temporally increases skin permeability by altering stratum corneum SC function (sonophoresis). The objective of this study was to evaluate the effect of variable ultrasound conditions on the permeation of diclofenac sodium DS with range of physicochemical properties through EpiDerm™. Permeation studies were carried out in vitro using Franz diffusion cell. HPLC method was used for the determination of the concentration of diclofenac sodium in receiving compartment. Parameters like ultrasound frequency, application time, amplitude, and mode of sonication and distance of ultrasound horn from skin were investigated, and the conditions where the maximum enhancement rate obtained were determined. Application of ultrasound enhanced permeation of diclofenac sodium across EpiDerm™ by fivefolds. The most effective enhancing parameters were power sonication of 20kHz frequency, 20% amplitude at continuous mode for 5min. Copyright © 2014. Published by Elsevier B.V.

Investigating the effect of STN-DBS stimulation and different frequency settings on the acoustic-articulatory features of vowels.

PubMed

Yilmaz, Atilla; Sarac, Elif Tuğba; Aydinli, Fatma Esen; Yildizgoren, Mustafa Turgut; Okuyucu, Emine Esra; Serarslan, Yurdal

2018-06-25

Parkinson's disease (PD) is the second most frequent progressive neuro-degenerative disorder. In addition to motor symptoms, nonmotor symptoms and voice and speech disorders can also develop in 90% of PD patients. The aim of our study was to investigate the effects of DBS and different DBS frequencies on speech acoustics of vowels in PD patients. The study included 16 patients who underwent STN-DBS surgery due to PD. The voice recordings for the vowels including [a], [e], [i], and [o] were performed at frequencies including 230, 130, 90, and 60 Hz and off-stimulation. The voice recordings were gathered and evaluated by the Praat software, and the effects on the first (F1), second (F2), and third formant (F3) frequencies were analyzed. A significant difference was found for the F1 value of the vowel [a] at 130 Hz compared to off-stimulation. However, no significant difference was found between the three formant frequencies with regard to the stimulation frequencies and off-stimulation. In addition, though not statistically significant, stimulation at 60 and 230 Hz led to several differences in the formant frequencies of other three vowels. Our results indicated that STN-DBS stimulation at 130 Hz had a significant positive effect on articulation of [a] compared to off-stimulation. Although there is not any statistical significant stimulation at 60 and 230 Hz may also have an effect on the articulation of [e], [i], and [o] but this effect needs to be investigated in future studies with higher numbers of participants.

Kinesthetic Investigations in the Physics Classroom

NASA Astrophysics Data System (ADS)

Whitworth, Brooke A.; Chiu, Jennifer L.; Bell, Randy L.

2014-02-01

Creating investigations that allow students to see physics in their everyday world and to be kinesthetically active outside of the traditional physics classroom can be incredibly engaging and effective. The investigations we developed were inquiry investigations in which students engaged in concrete experiences before we discussed the abstract concepts and derived the mathematical relationships. In this article, we describe the approach to inquiry used and an explanation of kinesthetic investigations in general. We then provide a description of several of the investigations and some examples of how students responded to them.

A Quasi-Experimental Study Investigating the Effect of Scent on Students' Memory of Multiplication Facts and Math Anxiety

ERIC Educational Resources Information Center

Leap, Evelyn M.

2013-01-01

This quasi-experimental study was conducted with two fifth grade classrooms to investigate the effect of scent on students' acquisition and retention of multiplication facts and math anxiety. Forty participants received daily instruction for nine weeks, using a strategy-rich multiplication program called Factivation. Students in the Double Smencil…

Investigating Students' Perceived Satisfaction, Behavioral Intention, and Effectiveness of E-Learning: A Case Study of the Blackboard System

ERIC Educational Resources Information Center

Liaw, S. S.

2008-01-01

Although the benefits of e-learning have been discussed in various previous studies; it is a critical issue of better understanding the reasons why some learners are dissatisfied with the e-learning experience. Therefore, this research investigates learners' satisfaction, behavioral intentions, and the effectiveness of the Blackboard e-learning…

Investigating the Relationship between Effective Communication of Spouse and Father-Child Relationship (Test Pattern Causes to Education Parents)

ERIC Educational Resources Information Center

Ataeifar, Robabeh; Amiri, Sholeh; Ali Nadi, Mohammad

2016-01-01

This research is targeted with the plan of father-child model or effective relationship mediating of spouses or investigating attachment style, personality traits, communication skills, and spouses' sexual satisfaction. Based on this, 260 people (father and child) were selected through random sampling method based on share. Participants were…

An Investigation into the Complex Process of Facilitating Effective Professional Learning: CPD Tutors' Practices under the Microscope

ERIC Educational Resources Information Center

Makopoulou, Kyriaki

2018-01-01

Background: Research evidence on what makes CPD effective is accumulating. Yet, fundamental questions about the specific features that lead to programme success. Furthermore, very little research investigates the nature and quality of CPD providers' (tutors) practices. Taking a closer look at how CPD providers support teachers to learn is…

An fMRI investigation of the effects of attempted naming on word retrieval in aphasia

PubMed Central

Heath, Shiree; McMahon, Katie L.; Nickels, Lyndsey A.; Angwin, Anthony; MacDonald, Anna D.; van Hees, Sophia; McKinnon, Eril; Johnson, Kori; Copland, David A.

2015-01-01

In healthy controls, picture naming performance can be facilitated by a single prior exposure to the same picture (“priming”). This priming phenomenon is utilized in the treatment of aphasia, which often includes repeated picture naming as part of a therapeutic task. The current study sought to determine whether single and/or multiple exposures facilitate subsequent naming in aphasia and whether such facilitatory effects act through normal priming mechanisms. A functional magnetic resonance imaging paradigm was employed to explore the beneficial effects of attempted naming in two individuals with aphasia and a control group. The timing and number of prior exposures was manipulated, with investigation of both short-term effects (single prior exposure over a period of minutes) and long-term effects (multiple presentations over a period of days). Following attempted naming, both short-term and long-term facilitated items showed improvement for controls, while only the long-term condition showed benefits at a behavioral level for the participants with aphasia. At a neural level, effects of long-term facilitation were noted in the left precuneus for one participant with aphasia, a result also identified for the equivalent contrast in controls. It appears that multiple attempts are required to improve naming performance in the presence of anomia and that for some individuals with aphasia the source of facilitation may be similar to unimpaired mechanisms engaged outside the language network. PMID:26074801

Investigation into the Coating and Desensitization Effect on HNIW of Paraffin Wax/Stearic Acid Composite System

NASA Astrophysics Data System (ADS)

Wang, Dong-Xu; Chen, Shu-Sen; Jin, Shao-Hua; Shu, Qing-Hai; Jiang, Zhen-Ming; Shang, Feng-Qin; Li, Jin-Xin

2016-01-01

2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (HNIW) was bonded by fluorine rubber and then desensitized by paraffin wax (PW), stearic acid (SA), and a PW/SA composite system using an aqueous suspension method. The coating and desensitization effects of the composite systems on HNIW and the influence of the addition of SA on the mechanical properties of the coated HNIW samples were studied. In addition, the PW/SA composite solution was simulated using a molecular dynamics method, and the relationship between the desensitization effect on HNIW and the properties of the composite solution was investigated. The results showed that the PW/SA composite system, of which the desensitization effect on HNIW was between those of the two desensitizers, could effectively coat HNIW and that the composite solution had the most stable and well-distributed state when using benzene as solvent with the mass ratio of PW/SA equal to 7/3 or 3/7, thus resulting in the best desensitization effect on HNIW. Moreover, the addition of stearic acid was successful in enhancing the mechanical properties of the coated HNIW samples.

Investigation of Correlation Effects in Nonlinear Optics

NASA Astrophysics Data System (ADS)

Friberg, Stephen Richard

This thesis deals with intensity correlation measurement methods as they apply to the study of light generated by a parametric downconversion process. The correlation properties of light can be used to distinguish between quantum mechanical light and classical light, where quantum mechanical light is electromagnetic radiation that can be accurately described only by a theory that quantizes the field. Spontaneous parametric downconversion produces quantum mechanical light, and we investigate some of its properties. A unique aspect of downconverted light is that pairs of photons are emitted in an interval that can be made smaller than the resolving time of any photon counting apparatus. Our experiments indicate that the interval is not affected by the bandwidth of the pump laser, nor by the length of the crystal. It is apparently determined only by the bandwidth of the detection apparatus, which in our experiment implies that the photons are produced in less than 1 psec, which is much shorter than the 100 psec resolution of our detection apparatus. The normalized cross-correlation functions for spontaneous downconversion are inversely dependent on intensity, but the normalized auto-correlations are independent of intensity. Measurements of the magnitude of the cross -correlations for several different pump beam intensities confirm this relationship. One of the inequalities imposed by classical theory relates the magnitude of the auto-correlations to the magnitude of the cross-correlations. Because of the inverse intensity dependence, this inequality is violated, thereby showing the quantum mechanical nature of the downconverted light. As an application of the large cross-correlations in downconversion, we apply the process to an optical communication channel which transmits information via coincidences between two light beams. Because of the strong discrimination against background provided by this technique, the channel can operate with large amounts of background

Investigation on the effectiveness of pretreatment in stormwater management technologies.

PubMed

Maniquiz-Redillas, Marla C; Geronimo, Franz Kevin F; Kim, Lee-Hyung

2014-09-01

The effectiveness of presettling basins as component of stormwater best management practice (BMP) technologies was investigated. Storm event monitoring and sediment collection were conducted from May 2009 to November 2012 on the presettling basins of the three BMP technologies designed to capture and treat stormwater runoff from highly impervious roads and parking lots. Data on captured runoff and sediment, total suspended solids (TSS) loadings, rainfall and runoff rate, sediment accumulation rate, as well as particle distribution and pollutant concentrations of sediment were gathered and analyzed along with the physical design characteristics of the presettling basins such as surface area and storage volume. Regression models were generated to determine significant relationships between design parameters. Results revealed that the storage volume ratio (ratio of storage volume of presettling basin to BMP) was an important parameter in designing the presettling basin of the BMP. For practicality, optimizing the design of the presettling basin means that the storage volume ratio should be determined based on the desired captured amount of runoff and sediment from runoff to limit the frequency of maintenance caused by the accumulation of sediment. It was recommended that pretreatment of runoff should be employed when the site in which the BMP is to be sited has high TSS loading and runoff rate, and is subjected to high intensity rainfall. Copyright © 2014. Published by Elsevier B.V.

Effect of biaxial strain on the magnetism of Fe16N2: Density-functional investigations

NASA Astrophysics Data System (ADS)

Zhou, Wei; Liu, Lijuan; Wu, Ping

2014-02-01

The effect of biaxial strain on the magnetism of α″-Fe16N2 was investigated by the first principles calculations. The GGA, GGA + U and HSE06 calculations give the same result that the magnetic moments increase with the biaxial strain in the ab plane. All non-equivalent Fe atoms contribute to the increase of magnetic moments, although the variations of inter-atomic distances between non-equivalent Fe and N are different. Additionally, the magnetic anisotropy of Fe16N2 could be controlled by the biaxial strain.

Comparative investigation on the effect of T-2 mycotoxin on lipid peroxidation and antioxidant status in different poultry species.

PubMed

Mézes, M; Barta, M; Nagy, G

1999-02-01

The effect of low dose T-2 toxin was investigated in chicken, duck and goose. The purpose of the present study was to investigate the effect of T-2 toxin on the lipid peroxidation and on the activity of glutathione redox system (amount of reduced and oxidised glutathione and the activity of glutathione peroxidase) in blood and liver. The treatment lasted days and two samples were taken, first at the time of lowest feed intake and second when the intake was the same as the control. It was found, that lipid per oxidation as detected by the amount of malondialdehyde increased in all of the species and tissues but the changes varied by species. The most sensitive species was goose followed by duck and chicken, and the most sensitive tissue was the liver followed by blood plasma and red blood cells.

Investigating the effect of emotional intelligence education on baccalaureate nursing students' emotional intelligence scores.

PubMed

Orak, Roohangiz Jamshidi; Farahani, Mansoureh Ashghali; Kelishami, Fatemeh Ghofrani; Seyedfatemi, Naima; Banihashemi, Sara; Havaei, Farinaz

2016-09-01

Nursing students, particularly at the time of entering clinical education, experience a great deal of stress and emotion typically related to their educational and clinical competence. Emotional intelligence is known to be one of the required skills to effectively cope with such feelings. The aim of this study was to investigate the effect of training on first-year nursing students' levels of emotional intelligence. This was a quasi-experiment study in which 69 first-year nursing students affiliated with Tehran University of Medical Sciences were assigned to either the control or the experimental groups. The study intervention included of an emotional intelligence educational program offered in eight two-hour sessions for eight subsequent weeks. In total, 66 students completed the study. The study groups did not differ significantly in terms of emotional intelligence scores before and after educational program. Although the educational program did not have an effect on students' emotional intelligence scores, this study finding can be explained. Limited time for exercising the acquired knowledge and skills may explain the non-significant findings. Moreover, our participants were exclusively first-year students who had no clinical experience and hence, might have felt no real need to learn emotional intelligence skills. Copyright © 2016 Elsevier Ltd. All rights reserved.

Flight investigation of the effect of tail boom strakes on helicopter directional control

NASA Technical Reports Server (NTRS)

Kelly, Henry L.; Crowell, Cynthia A.; Yenni, Kenneth R.; Lance, Michael B.

1993-01-01

A joint U.S. Army/NASA flight investigation was conducted utilizing a single-rotor helicopter to determine the effectiveness of horizontally mounted tail boom strakes on directional controllability and tail rotor power during low-speed, crosswind operating conditions. Three configurations were investigated: (1) baseline (strakes off), (2) single strake (strake at upper shoulder on port side of boom), and (3) double strake (upper strake plus a lower strake on same side of boom). The strakes were employed as a means to separate airflow over the tail boom and change fuselage yawing moments in a direction to improve the yaw control margin and reduce tail rotor power. Crosswind data were obtained in 5-knot increments of airspeed from 0 to 35 knots and in 30 deg increments of wind azimuth from 0 deg to 330 deg. At the most critical wind azimuth and airspeed in terms of tail rotor power, the strakes improved the pedal margin by 6 percent of total travel and reduced tail rotor power required by 17 percent. The increase in yaw control and reduction in tail rotor power offered by the strakes can expand the helicopter operating envelope in terms of gross weight and altitude capability. The strakes did not affect the flying qualities of the vehicle at airspeeds between 35 and 100 knots.

Investigation of coal properties and airborne respirable dust generation. Report of investigations/1998

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

Organiscak, J.A.; Page, S.J.

1998-10-01

Laboratory crushing experiments were conducted on a range of low- to high-volatile bituminous coals to investigate the various factors influencing airborne respirable dust (ARD) generation. This research was conducted to identify the principles of ARD liberation from the coal product. Five U.S. bituminous coals were uniformly prepared and processed through a double roll crusher located in a low-velocity wind tunnel. Experimental factors studied included inherent coal seam constituents, coal grindability, specific energy of crushing, product size characteristics, dust cloud electrostatic field, and specific ARD generated. The results of this investigation indicate that a combination of several factors are associated withmore » ARD generation. One factor is the effect of coal rank, described by the inherent moist fuel ratio, on the product size characteristics, defined by Schuhmann size function parameters. Another key factor is the effect of air dry loss (ADL) moisture in the coal seam on the breakage-induced electrostatic field of airborne dust. The effect of these factors is that different percentages of <10-micrometers coal particles are dispersed as ARD. A discussion of electrostatic field principles, coal ADL, and its effect on ARD generation is presented.« less

Investigation and modeling of the effects of light spectrum and incident angle on the growth of Chlorella vulgaris in photobioreactors.

PubMed

Souliès, Antoine; Legrand, Jack; Marec, Hélène; Pruvost, Jérémy; Castelain, Cathy; Burghelea, Teodor; Cornet, Jean-François

2016-03-01

An in-depth investigation of how various illumination conditions influence microalgal growth in photobioreactors (PBR) has been presented. Effects of both the light emission spectrum (white and red) and the light incident angle (0° and 60°) on the PBR surface were investigated. The experiments were conducted in two fully controlled lab-scale PBRs, a torus PBR and a thin flat-panel PBR for high cell density culture. The results obtained in the torus PBR were used to build the kinetic growth model of Chlorella vulgaris taken as a model species. The PBR model was then applied to the thin flat-panel PBR, which was run with various illumination conditions. Its detailed representation of local rate of photon absorption under various conditions (spectral calculation of light attenuation, incident angle influence) enabled the model to take into account all the tested conditions with no further adjustment. This allowed a detailed investigation of the coupling between radiation field and photosynthetic growth. Effects of all the radiation conditions together with pigment acclimation, which was found to be relevant, were investigated in depth. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:247-261, 2016. © 2016 American Institute of Chemical Engineers.

The Theory of Investigative Study and the Development of People

ERIC Educational Resources Information Center

Chen, Yuejun; Xu, Zhenhui

2017-01-01

Based on explaining investigative learning, this paper analyzed the characteristics of investigative learning and efficient methods to develop investigative learning, further to state the effects of investigative learning to train the abilities of university students especially the creative ability and the promotion effect to the mutual…

A Multilevel Investigation of Neighborhood Effects on Parental Warmth

ERIC Educational Resources Information Center

Tendulkar, Shalini A.; Buka, Stephen; Dunn, Erin C.; Subramanian, S. V.; Koenen, Karestan C.

2010-01-01

Although researchers recognize that social contexts shape parenting behaviors, the relationship between neighborhood environment and parenting remains poorly understood. To address this gap, we investigated the associations between compositional and contextual (structural, social, and safety) characteristics of neighborhoods and parental warmth.…

Cumulative Axial and Torsional Fatigue: An Investigation of Load-Type Sequencing Effects

NASA Technical Reports Server (NTRS)

Kalluri, Sreeramesh; Bonacuse, Peter J.

2000-01-01

Cumulative fatigue behavior of a wrought cobalt-base superalloy, Haynes 188 was investigated at 538 C under various single-step sequences of axial and torsional loading conditions. Initially, fully-reversed, axial and torsional fatigue tests were conducted under strain control at 538 C on thin-walled tubular specimens to establish baseline fatigue life relationships. Subsequently, four sequences (axial/axial, torsional/torsional, axial/torsional, and torsional/axial) of two load-level fatigue tests were conducted to characterize both the load-order (high/low) and load-type sequencing effects. For the two load-level tests, summations of life fractions and the remaining fatigue lives at the second load-level were computed by the Miner's Linear Damage Rule (LDR) and a nonlinear Damage Curve Approach (DCA). In general, for all four cases predictions by LDR were unconservative. Predictions by the DCA were within a factor of two of the experimentally observed fatigue lives for a majority of the cumulative axial and torsional fatigue tests.

Inhibitory control training for appetitive behaviour change: A meta-analytic investigation of mechanisms of action and moderators of effectiveness.

PubMed

Jones, Andrew; Di Lemma, Lisa C G; Robinson, Eric; Christiansen, Paul; Nolan, Sarah; Tudur-Smith, Catrin; Field, Matt

2016-02-01

Inhibitory control training (ICT) is a novel intervention in which participants learn to associate appetitive cues with inhibition of behaviour. We present a meta-analytic investigation of laboratory studies of ICT for appetitive behaviour change in which we investigate candidate mechanisms of action, individual differences that may moderate its effectiveness, and compare it to other psychological interventions. We conducted random-effects generic inverse variance meta-analysis on data from 14 articles (18 effect sizes in total). Participants who received ICT chose or consumed significantly less food or alcohol compared to control groups (SMD = 0.36, 95% CIs [0.24, 0.47]; Z = 6.18, p < .001; I(2) = 71%). Effect sizes were larger for motor (Go/No-Go and Stop Signal) compared to oculomotor (Antisaccade) ICT. The effects of ICT on behaviour were comparable to those produced by other psychological interventions, and effects of ICT on food intake were greater in participants who were attempting to restrict their food intake. The magnitude of the effect of ICT on behaviour was predicted by the proportion of successful inhibitions but was unrelated to the absolute number of trials in which appetitive cues were paired with the requirement to inhibit, or the contingency between appetitive cues and the requirement to inhibit. The effect of ICT on cue devaluation (primarily assessed with implicit association tests) was not statistically significant. Our analysis confirms the efficacy of ICT for short-term behaviour change in the laboratory, and we have demonstrated that its effectiveness may depend on pairings between appetitive cues and successful inhibition. We highlight the need for further research to translate these findings outside of the laboratory. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Seasonal Change Investigations

ERIC Educational Resources Information Center

Smith, Wendy

2009-01-01

The author describes how the yearlong Investigating Seasonal Change at North Ponds project enabled third-grade students to take on the role of environmental scientists, recording and analyzing environmental data from ponds near their school. The students used an array of technological tools to explore and report on the causes and effects of…

Investigation of organic adhesives for hybrid microcircuits

NASA Technical Reports Server (NTRS)

Perkins, K. L.; Licari, J. J.

1975-01-01

The properties of organic adhesives were investigated to acquire information for a guideline document regarding the selection of adhesives for use in high reliability hybrid microcircuits. Specifically, investigations were made of (1) alternate methods for determining the outgassing of cured adhesives, (2) effects of long term aging at 150 C on the electrical properties of conductive adhesives, (3) effects of shelf life age on adhesive characteristics, (4) bond strengths of electrically conductive adhesives on thick film gold metallization, (5) a copper filled adhesive, (6) effects of products outgassed from cured adhesives on device electrical parameters, (7) metal migration from electrically conductive adhesives, and (8) ionic content of electrically insulative adhesives. The tests performed during these investigations are described, and the results obtained are discussed.

Investigations on a novel photoacoustofluidic effect

NASA Astrophysics Data System (ADS)

Dumy, Gabriel; Hoyos, Mauricio; Aider, Jean-Luc

2017-11-01

Acoustic manipulation of micro-objects (particles, cells, bacteria) can be achieved using ultrasonic standing waves in a fluidic or microfluidic resonator. By matching resonator dimensions and acoustic field frequency it is possible to use acoustic radiation force (ARF) to gather the particles in the pressure nodal (or anti-nodal) plane, creating one or several aggregates. In standard operating conditions, they are stable for as long as needed in acoustic levitation at this position. In this study, we present a new unexpected phenomenon. After creating an aggregate of light-absorbing particles, we show that it is possible to force the breakup of the aggregate when lighting it with an electromagnetic wave of adequate wavelength and intensity. While the particles remain in levitation, they are rejected and propelled away from the aggregate, leading to its destruction. We show that this phenomenon depends on both amplitude of the ultrasonic field and lighting intensity. Various experiments with different types of particles and concentrations are used to discuss the possible phenomenon explanations. Moreover, investigations showed that this phenomenon applies to biological compounds such as red blood cells and stem cells, suggesting potential biomedical applications. We are thankful to doctoral school ``Frontières du vivant'' for supporting G. Dumy's PhD.

Weapon Simulator Test Methodology Investigation: Comparison of Live Fire and Weapon Simulator Test Methodologies and the Effects of Clothing and Individual Equipment on Marksmanship

DTIC Science & Technology

2016-09-15

METHODOLOGY INVESTIGATION: COMPARISON OF LIVE FIRE AND WEAPON SIMULATOR TEST METHODOLOGIES AND THE EFFECTS OF CLOTHING AND INDIVIDUAL EQUIPMENT ON...2. REPORT TYPE Final 3. DATES COVERED (From - To) October 2014 – August 2015 4. TITLE AND SUBTITLE WEAPON SIMULATOR TEST METHODOLOGY INVESTIGATION...COMPARISON OF LIVE FIRE AND WEAPON SIMULATOR TEST METHODOLOGIES AND THE EFFECTS OF CLOTHING AND INDIVIDUAL EQUIPMENT ON MARKSMANSHIP 5a. CONTRACT

Investigating the Effects of Asthma Medication on the Cognitive and Psychosocial Functioning of Primary School Children with Asthma

ERIC Educational Resources Information Center

Naude, H.; Pretorius, E.

2003-01-01

The effects of asthma medication on the cognitive and psychosocial functioning of primary school children with asthma are investigated. A questionnaire survey was conducted in a primary school in Stellenbosch (South Africa) with a population of six hundred and thirty-five students. Among these students, fifty-nine asthmatic children were…

Effects of Teacher Professional Characteristics on Student Achievement: An Investigation in Blended Learning Environment with Standards-Based Curriculum

ERIC Educational Resources Information Center

Çakir, Hasan; Bichelmeyer, Barbara A.

2016-01-01

Use of different teaching materials and curriculum for the same subjects is always a confounding factor in studies investigating teacher characteristics and student achievement. The purpose of this study is to understand the effects of different teacher qualities on student achievement in high schools with a standards-based curriculum delivered…

Interpreting and Reporting Effect Sizes in Research Investigations.

ERIC Educational Resources Information Center

Tapia, Martha; Marsh, George E., II

Since 1994, the American Psychological Association (APA) has advocated the inclusion of effect size indices in reporting research to elucidate the statistical significance of studies based on sample size. In 2001, the fifth edition of the APA "Publication Manual" stressed the importance of including an index of effect size to clarify…

Interdependence of stroke survivors' recovery and their relatives' attitudes and health: a contribution to investigating the causal effects.

PubMed

Barskova, Tatjana; Wilz, Gabriele

2007-10-15

One goal of the study was to test specific hypotheses concerning the interdependence of the stroke survivors' recovery and their caregiving partners' attitudes and health. The other aim was to find an applicable method for investigating causal effects on the rehabilitation of chronically sick persons in longitudinal studies with medium-sized samples. The recovery of 81 stroke survivors regarding the physical and mental functioning in everyday life and their caregiving partners' health and attitudes were assessed twice, once after the patients left the hospital and again one year later. We applied the structure equation modeling and the cross-lagged partial correlation analysis (CLPC) for testing causal effects. Particularly stroke victims' cognitive and emotional recovery seems to be influenced by psychosocial factors such as the caregiving partners' acceptance of a post-stroke life-situation. In contrast to this, the research suggests that the patients' recovery regarding physical functioning is not substantially affected by the partners, rather the patients' difficulties with motor functioning influence their partners' health. Caregivers merit attention as part of rehabilitation interventions. We recommend the CLPC for investigating causal effects in the complex interdependence of chronically sick persons' convalescence and their family members' health and state of mind in medium-sized samples.

Investigation on the reflector/moderator geometry and its effect on the neutron beam design in BNCT.

PubMed

Kasesaz, Y; Rahmani, F; Khalafi, H

2015-12-01

In order to provide an appropriate neutron beam for Boron Neutron Capture Therapy (BNCT), a special Beam Shaping Assembly (BSA) must be designed based on the neutron source specifications. A typical BSA includes moderator, reflector, collimator, thermal neutron filter, and gamma filter. In common BSA, the reflector is considered as a layer which covers the sides of the moderator materials. In this paper, new reflector/moderator geometries including multi-layer and hexagonal lattice have been suggested and the effect of them has been investigated by MCNP4C Monte Carlo code. It was found that the proposed configurations have a significant effect to improve the thermal to epithermal neutron flux ratio which is an important neutron beam parameter. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of investigator observation on gait parameters in individuals with and without chronic low back pain.

PubMed

Vickers, Joshua; Reed, Austin; Decker, Robert; Conrad, Bryan P; Olegario-Nebel, Marissa; Vincent, Heather K

2017-03-01

Despite the ubiquity of gait assessment in clinic and research, it is unclear how observation impacts gait, particularly in persons with chronic pain and psychological stress. We compared temporal spatial gait patterns in people with and without chronic low back pain (CLBP) when they were aware and unaware of being observed. This was a repeated-measures, deception study in 55 healthy persons (32.0±12.4 yr, 24.2±2.7kg/m 2 ) and persons with CLBP (51.9±17.9 yr, 27.8±4.4kg/m 2 ). Participants performed one condition in which they were unaware of observation (UNW), and three conditions under investigator observation: (1) aware of observation (AWA), (2) investigators watching cadence, (3) investigators watching step length. Participants walked across an 8.4m gait mat, while temporal spatial parameters of gait were collected. The Medical Outcomes Short Form (SF-12), Beck Depression Inventory (BDI), State Trait Anxiety Inventory (STAI), and Oswestry Disability Index (ODI) were completed. Significant condition by group interactions were found for velocity and step length (p<0.05). Main effects of study condition existed for all gait variables except for step width. Main effects of group (healthy, LBP) were significant for all variables except for step width (p<0.05). Regression analyses revealed that after accounting for age, sex, and SF-12 mental component score, BDI scores predict velocity changes during walking from the UNW to AWA conditions. These findings show that people change their gait patterns when being observed. Gait analyses may require additional trials before data can reliably be interpreted and used for clinical decision-making. Copyright © 2017 Elsevier B.V. All rights reserved.

Investigation of the bipolar effect in the thermoelectric material CaMg2Bi2 using a first-principles study.

PubMed

Gong, J J; Hong, A J; Shuai, J; Li, L; Yan, Z B; Ren, Z F; Liu, J-M

2016-06-28

The bipolar effect in relatively narrow band-gap thermoelectric (TE) compounds is a negative process deteriorating the TE properties particularly at higher temperatures. In this work, we investigate the TE performance of the compound CaMg2Bi2 using the first-principles calculation and semi-classical Boltzmann transport theory in combination with our experimental data. It is revealed that this compound exhibits a remarkable bipolar effect and temperature-dependent carrier concentration. The bipolar effect imposes remarkable influence on all the electron-transport related TE parameters. An effective carrier concentration neff as a function of temperature is proposed to account for the bipolar effect induced carrier excitations. The as-evaluated TE parameters then show good consistency with measured results. This work may shed light on our understanding of the bipolar effect in TE compounds.

Effects of polyphosphates and fluoride on hydroxyapatite dissolution: A pH-stat investigation.

PubMed

do Amaral, Jackeline Gallo; Delbem, Alberto Carlos Botazzo; Pessan, Juliano Pelim; Manarelli, Michele Mauricio; Barbour, Michele E

2016-03-01

This study investigated the immediate and sustained effect of sodium trimetaphosphate (TMP) and sodium hexametaphosphate (HMP) associated or not with fluoride (F) on hydroxyapatite (HA) dissolution using an erosion-like model, considering as well as the influence of salivary coating. Baseline dissolution rates were determined for HA discs using a pH-stat system. In the first set of experiments, HA discs were treated with 1100μgF/mL, 1% or 8% of HMP, 1% or 8% of TMP and 1100μgF/mL associated with 1% or 8% of HMP or TMP, totaling 9 groups (n=8). In a second phase, HA discs were kept in pooled human saliva at 37°C for 2h before treatment with deionised water and 1100μgF/mL associated with 1% or 8% of HMP or TMP, totaling 5 groups (n=8). The post-treatment dissolution rate was determined from three consecutive 30-min assays. Data were analysed using 2 and 3-way ANOVA followed by Fisher and Holm-Sidak methods, respectively (α=0.05). All test solutions promoted reduction in HA dissolution rate when compared to baseline control in the first post-treatment run (p<0.001). However, a synergistic effect was only observed between fluoride and 1% HMP. Moreover, the duration of inhibitory effect was greater when 8% HMP and 1 or 8% HMP associated with F were assessed (p<0.001). The presence of salivary coating led to higher protection for all groups when compared to discs without coating (p<0.001). The reduction of HA dissolution rate, as well as the duration of this effect were influenced by fluoride, type and concentration of phosphate salt and the presence of a salivary coating. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparative investigation of anticlastogenic effects in cell cultures of healthy donors and patients with nettle-rash.

PubMed

Arutyunyan, R M; Sarkisyan, T F; Oganesyan, G G; Durnev, A D

1994-03-01

In cultures of lymphocytes from 12 healthy donors and 12 patients with nettle-rash (NR) the anticlastogenic effect of the antimutagens WR-2721 (WR), bemitil (BM), tomerzol (TM) and interferon (IF) on the induction of chromosomal aberrations by photrin (PT) and dioxidine (DX) was investigated. There were no statistically significant differences between healthy donors and patients with NR in the levels of chromosomal aberrations that were spontaneous or induced by PT or DX. Statistically significant protective effects of BM, WR, TM and IF were demonstrated in cells of healthy donors after treatment with PT or DX, and after modification of the clastogenic action of PT in lymphocytes of NR patients. There was no protective effect of any of the anticlastogens after treatment of the lymphocyte cultures from NR patients with DX. That observation allows us to suggest the test of anticlastogenic action as a measure of sensitivity of the chromosomal apparatus in groups with different genetic risks.

75 FR 47588 - Trans Bay Cable, LLC; Notice of Institution of Section 206 Investigation and Refund Effective Date

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-06

... Cable, LLC; Notice of Institution of Section 206 Investigation and Refund Effective Date July 30, 2010...-116-000, pursuant to section 206 of the Federal Power Act (FPA), 16 U.S.C. 824e, concerning the justness and reasonableness of rates proposed by Trans Bay Cable, LLC (Trans Bay) in [[Page 47589

An Investigation of the Effects of a Non-Sexist Curriculum on One Preschool Group's Sex-Role Stereotypical Behavior.

ERIC Educational Resources Information Center

Kroeger, Janice E.

This study investigated effects of a nonsexist curriculum on preschoolers' dramatic role play behavior and usage of language and play space. A quasi-experimental design included two preschool groups, one of which received a treatment component that consisted of a nonsexist curriculum. The treatment group included 12 males and 10 females between…

Seeking Effectiveness and Equity in a Large College Chemistry Course: An HLM Investigation of Peer-Led Guided Inquiry

ERIC Educational Resources Information Center

Lewis, Scott E.; Lewis, Jennifer E.

2008-01-01

This study employed hierarchical linear models (HLM) to investigate Peer-Led Guided Inquiry (PLGI), a teaching practice combining cooperative learning and inquiry and tailored for a large class. Ultimately, the study provided an example of the effective introduction of a reform pedagogical approach in a large class setting. In the narrative, the…

Developing an Interactive Non-Formal Chemistry Setting and Investigating Its Effectiveness on High School Students' Attitudes towards Chemistry

ERIC Educational Resources Information Center

Demircioglu, Gökhan

2016-01-01

The main purpose of this study is to design an interactive non-formal chemistry environment and investigate its effectiveness on high school students' attitudes towards chemistry. Besides that, it is tried to determine to what extent students correlate these concepts with daily life. 14 voluntary students (5 female, 9 male) from different levels…

Bimanual coupling paradigm as an effective tool to investigate productive behaviors in motor and body awareness impairments.

PubMed

Garbarini, Francesca; Pia, Lorenzo

2013-11-05

When humans move simultaneously both hands strong coupling effects arise and neither of the two hands is able to perform independent actions. It has been suggested that such motor constraints are tightly linked to action representation rather than to movement execution. Hence, bimanual tasks can represent an ideal experimental tool to investigate internal motor representations in those neurological conditions in which the movement of one hand is impaired. Indeed, any effect on the "moving" (healthy) hand would be caused by the constraints imposed by the ongoing motor program of the 'impaired' hand. Here, we review recent studies that successfully utilized the above-mentioned paradigms to investigate some types of productive motor behaviors in stroke patients. Specifically, bimanual tasks have been employed in left hemiplegic patients who report illusory movements of their contralesional limbs (anosognosia for hemiplegia). They have also been administered to patients affected by a specific monothematic delusion of body ownership, namely the belief that another person's arm and his/her voluntary action belong to them. In summary, the reviewed studies show that bimanual tasks are a simple and valuable experimental method apt to reveal information about the motor programs of a paralyzed limb. Therefore, it can be used to objectively examine the cognitive processes underpinning motor programming in patients with different delusions of motor behavior. Additionally, it also sheds light on the mechanisms subserving bimanual coordination in the intact brain suggesting that action representation might be sufficient to produce these effects.

An investigation into the effect of surveillance drones on textile evidence at crime scenes.

PubMed

Bucknell, Alistair; Bassindale, Tom

2017-09-01

With increasing numbers of Police forces using drones for crime scene surveillance, the effect of the drones on trace evidence present needs evaluation. In this investigation the effect of flying a quadcopter drone at different heights over a controlled scene and taking off at different distances from the scene were measured. Yarn was placed on a range of floor surfaces and the number lost or moved from their original position was recorded. It was possible to estimate "safe" distances above and take off distance from the bath mat (2m and 1m respectively), and carpet tile (3m and 1m) which were the roughest surfaces. The maximum distances tested of 5m above and 2m from was not far enough to prevent significant disturbance with the other floor surfaces. This report illustrates the importance of considering the impact of new technologies into a forensic workflow on established forensic evidence prior to implementation. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.

Hyperspectral imaging as a technique for investigating the effect of consolidating materials on wood

NASA Astrophysics Data System (ADS)

Bonifazi, Giuseppe; Serranti, Silvia; Capobianco, Giuseppe; Agresti, Giorgia; Calienno, Luca; Picchio, Rodolfo; Lo Monaco, Angela; Santamaria, Ulderico; Pelosi, Claudia

2017-01-01

The focus of this study was to investigate the potential of hyperspectral imaging (HSI) in the monitoring of commercial consolidant products applied on wood samples. Poplar (Populus spp.) and walnut (Juglans Regia L.) were chosen for the consolidant application. Both traditional and innovative products were selected, based on acrylic, epoxy, and aliphatic compounds. Wood samples were stressed by freeze/thaw cycles in order to cause material degradation without the loss of wood components. Then the consolidant was applied under vacuum. The samples were finally artificially aged for 168 h in a solar box chamber. The samples were acquired in the short wave infrared (1000 to 2500 nm) range by SISUChema XL™ device (Specim, Finland) after 168 h of irradiation. As comparison, color measurement was also used as an economic, simple, and noninvasive technique to evaluate the deterioration and consolidation effects on wood. All data were then processed adopting a chemometric approach finalized to define correlation models, HSI based, between consolidating materials, wood species, and short-time aging effects.

Investigating the effect of independent, blinded digital image assessment on the STOP GAP trial.

PubMed

Patsko, Emily; Godolphin, Peter J; Thomas, Kim S; Hepburn, Trish; Mitchell, Eleanor J; Craig, Fiona E; Bath, Philip M; Montgomery, Alan A

2017-02-02

Blinding is the process of keeping treatment assignment hidden and is used to minimise the possibility of bias. Trials at high risk of bias have been shown to report larger treatment effects than low-risk studies. In dermatology, one popular method of blinding is to have independent outcome assessors who are unaware of treatment allocation assessing the endpoint using digital photographs. However, this can be complex, expensive and time-consuming. The objective of this study was to compare the effect of blinded and unblinded outcome assessment on the results of the STOP GAP trial. The STOP GAP trial compared prednisolone to ciclosporin in treating pyoderma gangrenosum. Participants' lesions were measured at baseline and at 6 weeks to calculate the primary outcome, speed of healing. Independent blinded assessors obtained measurements from digital photographs using specialist software. In addition, unblinded treating clinicians estimated lesion area by measuring length and width. The primary outcome was determined using blinded measurements where available, otherwise unblinded measurements were used (method referred to as trial measurements). In this study, agreement between the trial and unblinded measurements was determined using the intraclass correlation coefficient (ICC). The STOP GAP trial's primary analysis was repeated using unblinded measurements only. We introduced differential and nondifferential error in unblinded measurements and investigated the effect on the STOP GAP trial's primary analysis. Eighty-six (80%) of the 108 patients were assessed using digital images. Agreement between trial and unblinded measurements was excellent (ICC = 0.92 at baseline; 0.83 at 6 weeks). There was no evidence that the results of the trial primary analysis differed according to how the primary outcome was assessed (p value for homogeneity = 1.00). Blinded digital image assessment in the STOP GAP trial did not meaningfully alter trial conclusions compared with