Effect Measurements (effect + measurement)

Distribution by Scientific Domains
Distribution within Physics and Astronomy

Kinds of Effect Measurements

  • hall effect measurement


  • Selected Abstracts


    Significant improvement in sleep in people with intellectual disabilities living in residential settings by non-pharmaceutical interventions

    JOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 8 2009
    T. Hylkema
    Abstract Background Although about 15 to 50 percent of people with intellectual disabilities (ID) living in residential settings suffer from sleep problems, scant attention is paid to these problems. Most available studies focus on pharmaceutical solutions. In this study we focus on improving sleep in people with intellectual disabilities living in residential settings by non-pharmaceutical interventions. Method The design is a multiple case study using actigraphy. Following a baseline measurement of people with ID, we recommended an intervention such as bedtime scheduling. This was followed by an effect measurement. Results Sleep efficiency, sleep latency and rising latency improved significantly. The time spent in bed also decreased significantly and the hours of sleep while in bed increased significantly. Conclusion For people with ID, sleep can be improved by non-pharmaceutical interventions. A multidisciplinary approach is helpful in selecting an adequate intervention. [source]


    Activation energy of Mg in a -plane Ga1,xInx N (0 < x < 0.17)

    PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 6 2009
    Daisuke Iida
    Abstract We investigated the electrical properties of Mg-doped Ga1,xInx N grown on an a -plane template. High-hole-concentration p-type Mg-doped Ga1,xInx N films with an InN molar fraction of 0.17 were fabricated on sidewall-epitaxial-lateral overgrown a -plane GaN grown on an r -plane sapphire substrate by MOVPE. Variable-temperature Hall effect measurement showed that a maximum hole concentration of 1.4 × 1019 cm,3 for x = 0.17 was reproducibly achieved at room temperature. The activation energy of Mg acceptors in Mg-doped a -plane Ga0.83In0.17N was found to be as low as 48 meV. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Properties of InAs co-doped ZnO thin films prepared by pulsed laser deposition

    CRYSTAL RESEARCH AND TECHNOLOGY, Issue 12 2009
    J. Elanchezhiyan
    Abstract InAs co-doped ZnO films were grown on sapphire substrates by pulsed laser deposition. The grown films have been characterized using X-ray diffraction (XRD), Hall effect measurements, Atomic force microscope (AFM) and Field emission scanning electron microscope (FESEM) in order to investigate the structural, electrical, morphological and elemental properties of the films respectively. XRD analysis showed that all the films were highly orientated along the c-axis. It was observed from Hall effect measurements that InAs co-doped ZnO films were of n-type conductivity. In addition, the presence of In and As has been confirmed by Energy dispersive X-ray analysis. AFM images revealed that the surface roughness of the films was decreased upon the co-doping. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Microstructural, thermal, and electrical properties of Bi1.7V0.3Sr2Ca2Cu3Ox glass-ceramic superconductor

    CRYSTAL RESEARCH AND TECHNOLOGY, Issue 12 2004
    T. S. Kayed
    Abstract A glass-ceramic Bi1.7V0.3Sr2Ca2Cu3Ox superconductor was prepared by the melt-quenching method. The compound was characterized by scanning electron microscopy, x-ray diffraction, differential thermal analysis, current-voltage characteristics, transport resistance measurements, and Hall effect measurements. Two main phases (BSCCO 2212 and 2223) were observed in the x-ray data and the values of the lattice parameters quite agree with the known values for 2212 and 2223 phases. The glass transition temperature was found to be 426 °C while the activation energy for crystallization of glass has been found to be Ea = 370.5 kJ / mol. This result indicates that the substitution of vanadium increased the activation energy for the BSCCO system. An offset Tc of 80 K was measured and the onset Tc was 100 K. The Hall resistivity ,H was found to be almost field-independent at the normal state. A negative Hall coefficient was observed and no sign reversal of ,H or RH could be noticed. The mobility and carrier density at different temperatures in the range 140-300 K under different applied magnetic fields up to 1.4 T were also measured and the results are discussed. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Intra- and interlaboratory calibration of the DR CALUX® bioassay for the analysis of dioxins and dioxin-like chemicals in sediments

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2004
    Harrie T. Besselink
    Abstract In the Fourth National Policy Document on Water Management in the Netherlands [1], it is defined that in 2003, in addition to the assessment of chemical substances, special guidelines for the assessment of dredged material should be recorded. The assessment of dredged material is based on integrated chemical and biological effect measurements. Among others, the DR CALUX® (dioxin responsive,chemically activated luciferase expression) bioassay has tentatively been recommended for inclusion in the dredged material assessment. To ensure the reliability of this bioassay, an intra- and interlaboratory validation study, or ring test, was performed, organized by the Dutch National Institute for Coastal and Marine Management (RIKZ) in cooperation with BioDetection Systems BV (BDS). The intralaboratory repeatability and reproducibility and the limit of detection (LOD) and quantification (LOQ) of the DR CALUX bioassay were determined by analyzing sediment extracts and dimethyl sulfoxide (DMSO) blanks. The highest observed repeatability was found to be 24.1%, whereas the highest observed reproducibility was calculated to be 19.9%. Based on the obtained results, the LOD and LOQ to be applied for the bioassay are 0.3 and 1.0 pM, respectively. The interlaboratory calibration study was divided into three phases, starting with analyzing pure chemicals. During the second phase, sediment extracts were analyzed, whereas in the third phase, whole sediments had to be extracted, cleaned, and analyzed. The average interlaboratory repeatability increased from 14.6% for the analysis of pure compound to 26.1% for the analysis of whole matrix. A similar increase in reproducibility with increasing complexity of handlings was observed with the interlaboratory reproducibility of 6.5% for pure compound and 27.9% for whole matrix. The results of this study are intended as a starting point for implementing the integrated chemical,biological assessment strategy and for systematic monitoring of dredged materials and related materials in the coming years. [source]


    The reaction of OH with acetaldehyde and deuterated acetaldehyde: Further insight into the reaction mechanism at both low and elevated temperatures

    INTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 8 2006
    Philip H. Taylor
    The pulsed laser photolysis/laser-induced fluorescence technique has been used to conduct additional measurements of the gas-phase CH3CHO + OH reaction. These measurements were conducted to verify the complex temperature dependence previously observed by the authors and to acquire mechanistic information about the reaction mechanism in the form of primary kinetic isotope effects. Primary kinetic isotope effect measurements at temperatures of 297, 383, 600, and 860 K indicate that H abstraction from the acetyl group dominates that of the methyl group at low to modest temperatures (,600 K) and H abstraction from the methyl group dominates that from the acetyl group at higher temperatures (860 K). A bi-exponential © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 489,495, 2006 [source]


    Wet-oxidation effect on p-type transparent conducting CuAlO2 thin film

    PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 15 2005
    Dae-Sung Kim
    Abstract The wet-oxidation effect on optical and electrical properties of CuAlO2 thin films was investigated with different water vapor pressures. Preferential (006) oriented films were ob-tained after wet-oxidation. The transmittance was 50,85% for the visible range and the optical band gap was estimated to be 3.96,4.20 eV. The p-type nature of the films was confirmed by Hall effect measurements. The resistivity and transmittance were increased as water vapor pressure, and these phenomena were caused by the decrease of lower oxides with higher oxygen pressure. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Study of the electrical conductivity and thermoelectric power of In2Te5 single crystals

    PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 3 2003
    M. M. Nassary
    Abstract In the present study, single crystals of defect semiconductor In2Te5 were grown by the Bridgman technique. An investigation was made on the Hall effect, electrical conductivity and thermoelectric power of In2Te5 monocrystal in the temperature ranging from 200 to 500 K. The investigated samples were P-type conducting. The Hall coefficient yields a room-temperature carrier concentration of (7.7 × 109 cm,3). The bandgap was found to be (,Eg = 0.993 eV). Hence, a combination of the electrical conductivity and Hall effect measurements enable us to study the influence of temperature on the Hall mobility (,) and to discuss the scattering mechanism of the charge carriers, also the present investigation involves thermoelectric power measurements of In2Te5 single crystal: these measurements enable us to determine many physical parameters such as carriers mobilities, effective masses of free charge carriers (mp*, mn*, diffusion coefficients (Dp, Dn) and diffusion lengths as well as the relaxation time (,p, ,n). (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Impurity levels in the layered semiconductor p-GaSe doped with group V elements As, Bi and Sb

    PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 15 2005
    S. Shigetomi
    Abstract The radiative and non radiative recombination mechanisms in the As, Sb and Bi-doped GaSe have been investigated on the basis of photoluminescence (PL) and Hall effect measurements. The PL features (at 77 K) related to the impurity levels coming from the As, Sb and Bi atoms are dominated by a broad emission band at about 1.7 eV. From the temperature dependences of the peak energy and PL intensity and the dependence of excitation intensity of peak energy, it was found that the 1.7 eV emission band is due to the transition from the shallow donor level at about 0.08 eV below the conduction band to the deep acceptor. In addition it was found, from the temperature dependence of hole concentration, that a deep acceptor level at about 0.6 eV above the valence band is formed by the doping atoms. It is associated with defects or defect complexes. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    AlGaN metal-semiconductor-metal structure for pressure sensing applications

    PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2006
    Z. Hassan
    Abstract We report on the effects of hydrostatic pressure on an Alx Ga1,xN metal-semiconductor-metal (MSM) structure with Ni Schottky contacts. Structural, optical, and electrical analysis of the Alx Ga1,xN film were carried out using atomic force microscopy (AFM), high resolution X-ray diffraction (HRXRD), Raman, UV-visible spectroscopy, and Hall effect measurements. The AlN mole fraction in this film was determined to be about 24%. Current-voltage (I-V) measurements of the MSM structure under hydrostatic pressure indicated a linear decrease of current with pressure. The decrease of the current under pressure was attributed to an increase in barrier height, tentatively attributed to a combination of piezoelectric and band structure effects. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    High and low energy proton irradiation effects on AlGaN/GaN HFETs

    PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2006
    G. Sonia
    Abstract AlGaN/GaN heterojunction field effect transistors (HFETs) have been irradiated with protons at 68 MeV and 2 MeV with fluences up to 1013 cm,2 in order to simulate operation in space. Hall effect measurements, dc characteristics and RF load pull measurements at 2 GHz do not reveal significant changes indicating the suitability of the transistors for reliable operation in space. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Predominant point defects in tellurium saturated CdTe

    PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 4 2006
    P. Fochuk
    Abstract High temperature Hall effect measurements at 570,1070 K under well defined Te vapor pressure in CdTe single crystals grown by THM and Bridgman techniques were made. Both the free carrier density versus Te vapour pressure value and temperature dependencies were studied. At heating up till ,870 K the hole density was Te vapor pressure independent, but it varied in different samples from 1 × 1016 to 1 × 1017 cm,3. At higher temperatures the conductivity becomes of intrinsic type, turning then into n-type one. A theoretical analysis of native point defects contents at different conditions in the framework of Krögers quasichemical formalism was performed. It resulted in the impossibility of mutual compensation of native donors and acceptors proposed by different authors. The results were explained assuming the presence of an electrically active foreign point defect , the oxygen interstitial acceptor. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Structural and electrical characterization of a -plane GaN grown on a -plane SiC

    PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2003
    M. D. Craven
    Abstract Planar nonpolar () a -plane GaN thin films were grown on () a -plane 6H-SiC substrates via metalorganic chemical vapor deposition by depositing a high temperature AlN buffer layer prior to the epitaxial GaN growth. The orientation of the GaN film and AlN buffer layer directly match that of the SiC substrate, as determined by on- and off-axis X-ray diffraction measurements. The morphological evolution of GaN grown on the AlN buffer layers was investigated using atomic force microscopy. Microstructural characterization of the coalesced a -plane GaN films provided by plan-view transmission electron microscopy revealed threading dislocation and stacking fault densities of ,3 × 1010 cm,2 and ,7 × 105 cm,1, respectively. Structural comparisons to a -plane GaN films grown on r -plane sapphire substrates are presented. Si-doped films were grown with a variety of Si/Ga ratios and electrically characterized using Hall effect measurements. A maximum Hall mobility of 109 cm2/Vs was attained at a carrier concentration of 1.8 × 1019 cm,3. [source]


    Radiation-induced defects and their transformations in oxygen-rich germanium crystals

    PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 2 2003
    V. P. Markevich
    Abstract Defects induced by irradiation with fast electrons and 60Co gamma-rays in oxygen-rich Ge crystals have been studied by means of infrared absorption, deep level transient spectroscopy (DLTS) and Hall effect measurements. It is found that the vacancy,oxygen (V,O) complex in Ge has three charge states (doubly negative, singly negative and neutral ones) and two corresponding energy levels in the gap at about Ec,,,0.21 eV and Ev + 0.27 eV. Three absorption bands at 621.4, 669.1 and 716.2 cm,1 are identified as oxygen-related asymmetrical stretching vibrations for the neutral, singly negatively charged and doubly negatively charged states of the V,O complex, respectively. [source]


    Ageing in granular aluminium insulating thin films

    ANNALEN DER PHYSIK, Issue 12 2009
    J. Delahaye
    Abstract We present a new set of electrical field effect measurements on granular aluminium insulating thin films. We have explored how the conductance relaxations induced by gate voltage changes depend on the age of the system, namely the time elapsed since its quench at low temperature. A clear age dependence of the relaxations is seen, qualitatively similar to ageing effects seen in other well studied glassy systems such as spin glasses or polymers. We explain how our results differ from the previous ones obtained with different protocols in indium oxide and granular aluminium thin films. Our experimental findings bring new information on the dynamics of the system and put new constraints on the theoretical models that may explain slow conductance relaxations in disordered insulators. [source]