845 research outputs found

    Examining the impact of meaning and resilience on survivors\u27 life satisfaction after Hurricane Harvey

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    The experience of a traumatic event such as a natural disaster can often lead individuals to suffer a variety of negative sequelae, including the development of posttraumatic stress symptoms. However, certain positive psychological constructs like meaning and resilience have been shown to mitigate these consequences. The purpose of this study was to explore the contributions of meaning and resilience to the life satisfaction of individuals (N = 55) impacted by 2017‚Äôs Hurricane Harvey. It was hypothesized that not only would meaning and resilience be significantly and positively related to life satisfaction but that meaning would contribute more to the prediction of life satisfaction than resilience. Significant positive relationships were found between meaning and life satisfaction (r = .51, p ‚ȧ .05) and between resilience and life satisfaction (r = .32, p ‚ȧ .05) as was expected. After conducting a multiple regression analysis, meaning was also found to significantly predict life satisfaction (ő≤ = .46, t(54) = 3.48, p = .001, pr2 = .19), and did so to a greater extent than resilience (ő≤ = .13, t(54) = .97, p = .34, pr2 = .02), which was not a statistically significant predictor in this instance. The implications of these findings are discussed, along with study strengths, limitations, and directions for research

    Coherent population oscillations with nitrogen-vacancy color centers in diamond

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    We present results of our research on two-field (two-frequency) microwave spectroscopy in nitrogen-vacancy (NV-) color centers in a diamond. Both fields are tuned to transitions between the spin sublevels of the NV- ensemble in the 3A2 ground state (one field has a fixed frequency while the second one is scanned). Particular attention is focused on the case where two microwaves fields drive the same transition between two NV- ground state sublevels (ms=0 -> ms=+1). In this case, the observed spectra exhibit a complex narrow structure composed of three Lorentzian resonances positioned at the pump-field frequency. The resonance widths and amplitudes depend on the lifetimes of the levels involved in the transition. We attribute the spectra to coherent population oscillations induced by the two nearly degenerate microwave fields, which we have also observed in real time. The observations agree well with a theoretical model and can be useful for investigation of the NV relaxation mechanisms.Comment: 17 page

    Microwave saturation spectroscopy of nitrogen-vacancy ensembles in diamond

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    Negatively-charged nitrogen-vacancy (NV‚ąí^-) centers in diamond have generated much recent interest for their use in sensing. The sensitivity improves when the NV ground-state microwave transitions are narrow, but these transitions suffer from inhomogeneous broadening, especially in high-density NV ensembles. To better understand and remove the sources of broadening, we demonstrate room-temperature spectral "hole burning" of the NV ground-state transitions. We find that hole burning removes the broadening caused by magnetic fields from 13^{13}C nuclei and demonstrate that it can be used for magnetic-field-insensitive thermometry.Comment: Main text: 5 pages, 4 figures. Supplement: 6 pages, 3 figure

    Teacher Quality and Sorting across Traditional Public and Charter Schools in the Detroit Metropolitan Region

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    In the quest to raise student achievement in low-performing urban schools, researchers often point to the central importance of recruitment and retention of a high quality teacher workforce

    Examining the impact of meaning and resilience on survivors' life satisfaction after Hurricane Harvey

    Get PDF
    The experience of a traumatic event such as a natural disaster can often lead individuals to suffer a variety of negative sequelae, including the development of posttraumatic stress symptoms. However, certain positive psychological constructs like meaning and resilience have been shown to mitigate these consequences. The purpose of this study was to explore the contributions of meaning and resilience to the life satisfaction of individuals (N = 55) impacted by 2017‚Äôs Hurricane Harvey. It was hypothesized that not only would meaning and resilience be significantly and positively related to life satisfaction but that meaning would contribute more to the prediction of life satisfaction than resilience. Significant positive relationships were found between meaning and life satisfaction (r = .51, p ‚ȧ .05) and between resilience and life satisfaction (r = .32, p ‚ȧ .05) as was expected. After conducting a multiple regression analysis, meaning was also found to significantly predict life satisfaction (ő≤ = .46, t(54) = 3.48, p = .001, pr2 = .19), and did so to a greater extent than resilience (ő≤ = .13, t(54) = .97, p = .34, pr2 = .02), which was not a statistically significant predictor in this instance. The implications of these findings are discussed, along with study strengths, limitations, and directions for research

    A segmented total energy detector (sTED) for (n, ő≥) cross section measurements at n_TOF EAR2

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    This work was supported in part by the I+D+i grant PGC2018-096717-B-C21 funded by MCIN/AEI/10.13039/501100011033 and by the European Commission H2020 Framework Programme project SANDA (Grant agreement ID: 847552).The neutron time-of-flight facility n_TOF is characterised by its high instantaneous neutron intensity, high resolution and broad neutron energy spectra, specially conceived for neutron-induced reaction cross section measurements. Two Time-Of-Flight (TOR) experimental areas are available at the facility: experimental area 1 (EAR1), located at the end of the 185 m horizontal flight path from the spallation target, and experimental area 2 (EAR2), placed at 20 m from the target in the vertical direction. The neutron fluence in EAR2 is similar to 300 times more intense than in EARL in the relevant time-of-flight window. EAR2 was designed to carry out challenging cross-section measurements with low mass samples (approximately 1 mg), reactions with small cross-sections or/and highly radioactive samples. The high instantaneous fluence of EAR2 results in high counting rates that challenge the existing capture systems. Therefore, the sTED detector has been designed to mitigate these effects. In 2021, a dedicated campaign was done validating the performance of the detector up to at least 300 keV neutron energy. After this campaign, the detector has been used to perform various capture cross section measurements at n_TOF EAR2.MCIN/AEI/10.13039/501100011033 I+D+i PGC2018-096717-B-C21European Commission H2020 Framework Programme SANDA 84755

    Experimental setup and procedure for the measurement of the 7Be(n,p)7Li reaction at n_TOF

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    Following the completion of the second neutron beam line and the related experimental area (EAR2) at the n_TOF spallation neutron source at CERN, several experiments were planned and performed. The high instantaneous neutron flux available in EAR2 allows to investigate neutron induced reactions with charged particles in the exit channel even employing targets made out of small amounts of short-lived radioactive isotopes. After the successful measurement of the 7Be(n,) cross section, the 7Be(n,p)7Li reaction was studied in order to provide still missing cross section data of relevance for Big Bang Nucleosynthesis (BBN), in an attempt to find a solution to the cosmological Lithium abundance problem. This paper describes the experimental setup employed in such a measurement and its characterization.Séptimo Programa Marco de la Comunidad Europea de la Energía Atómica (Euratom)-Proyecto CHANDA (No. 605203)Narodowe Centrum Nauki (NCN)-UMO-2012/04/M/ST2/00700-UMO-2016/22/M/ST2/00183Croatian Science Foundation-HRZZ 168

    Longitudinal spin relaxation in nitrogen-vacancy ensembles in diamond

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    We present an experimental study of the longitudinal electron-spin relaxation of ensembles of negatively charged nitrogen-vacancy (NV ) centers in diamond. The measurements were performed with samples having different NV- concentrations and at different temperatures and magnetic fields. We found that the relaxation rate T1-1 increases when transition frequencies in NV- centers with different orientations become degenerate and interpret this as cross-relaxation caused by dipole-dipole interaction.Comment: 11 pages, 9 figure

    Probe spectroscopy in an operating magneto-optical trap: the role of Raman transitions between discrete and continuum atomic states

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    We report on cw measurements of probe beam absorption and four-wave-mixing spectra in a 85^{85}Rb magneto-optical trap taken while the trap is in operation. The trapping beams are used as pump light. We concentrate on the central feature of the spectra at small pump-probe detuning and attribute its narrow resonant structures to the superposition of Raman transitions between light-shifted sublevels of the ground atomic state and to atomic recoil processes. These two contributions have different dependencies on trap parameters and we show that the former is inhomogeneously broadened. The strong dependence of the spectra on the probe-beam polarization indicates the existence of large optical anisotropy of the cold-atom sample, which is attributed to the recoil effects. We point out that the recoil-induced resonances can be isolated from other contributions, making pump-probe spectroscopy a highly sensitive diagnostic tool for atoms in a working MOT.Comment: 9 pages, 8 figure
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