2,617 research outputs found

    Examining the Role of the Catholic Environment in Students’ Search for Meaning

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    Emerging research illustrates that undergraduate students are searching for meaning in their lives, yet postsecondary institutions generally do little to support them in exploring such issues (Astin et al., 2005b). We speculated that religiously affiliated institutions might offer guidance on supporting students’ spiritual development, and thus examined students in the context of Catholic postsecondary environments, focusing on whether the students’ religious affiliations and perceptions of their institution as supporting their spiritual development affected their search for meaning. Further, we examined the aspects of the environment that strengthened students’ perceptions of their college environment as closely aligned with the Catholic mission, and thus supportive of their spiritual development. We discuss implications for secular and religious institutions

    Gas-phase spin relaxation of 129Xe

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    Journal ArticleWe have completed an extensive study of 129Xe longitudinal spin relaxation in the gas phase, involving both intrinsic and extrinsic mechanisms. The dominant intrinsic relaxation is mediated by the formation of persistent Xe2 van der Waals dimers. The dependence of this relaxation on applied magnetic field yields the relative contributions of the spin-rotation and chemical-shift-anisotropy interactions; the former dominates at magnetic fields below a few tesla. This relaxation also shows an inverse quadratic dependence on temperature T; the maximum low-field intrinsic relaxation for pure xenon at room temperature (measured here to be 4.6 h, in agreement with previous work) increases by ~60% for T=100 °C. The dominant extrinsic relaxation is mediated by collisions with the walls of the glass container. Wall relaxation was studied in silicone-coated alkali-metal-free cells, which showed long (many hours or more) and robust relaxation times, even at the low magnetic fields typical for spin-exchange optical pumping (~3 mT). The further suppression of wall relaxation for magnetic fields above a few tesla is consistent with the interaction of 129Xe with paramagnetic spins on or inside the surface coating. At 14.1 T and sufficiently low xenon density, we measured a relaxation time T1 =99 h, with an inferred wall-relaxation time of 174 h. A prototype large storage cell (12 cm diameter) was constructed to take advantage of the apparent increase in wall-relaxation time for cells with a smaller surfaceto- volume ratio. The measured relaxation time in this cell at 3 mT and 100 °C was 5.75 h. Such a cell (or one even larger) could be used to store many liters of hyperpolarized 129Xe produced by a flow-through polarizer and accumulator for up to three times longer than currently implemented schemes involving freezing xenon in liquid nitrogen

    Radiation imaging apparatus

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    A radiation imaging system using a charge multiplier and a position sensitive anode in the form of periodically arranged sets of interconnected anode regions for detecting the position of the centroid of a charge cloud arriving thereat from the charge multiplier. Various forms of improved position sensitive anodes having single plane electrode connections are disclosed. Various analog and digital signal processing systems are disclosed, including systems which use the fast response of microchannel plates, anodes and preamps to perform scintillation pulse height analysis digitally

    Cultures of transformation: An integrated framework for transformative action

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    The challenges posed by climate change have generated many initiatives that seek to implement societal transformations. In most cases, these focus on technology developments, adoption and diffusion but neglect the social and cultural dimensions of a transformation. Insights from systems and behavioural sciences can provide valuable guidance on these aspects, but the utility of this literature is limited by two factors. Firstly, the literature on the intersection between social transformation and psychological processes of behaviour change by individuals is limited. Secondly, the complex technical nature of much of the transition relevant literature limits its accessibility by stakeholders outside academia. We seek to address these challenges through the development of a transdisciplinary Transformation Process Framework for use as a ‘knowledge integration’ tool as part of a co-design process for transformative change. The Framework: (1) develops a systematic narrative of the transformational changes that need to be triggered at multiple scales (from individual to society), (2) generates a map to identify key variables, drivers, and blockers in a transformation process integrating different knowledge from fragmented disciplines; (3) serves as a tool to support the exploration of relevant academic (and other) literature to collate and utilise relevant knowledge. © 2022Suggestion H.P., A.H.S. and A.A.K was supported by the H2020 European Commission Project ‘PARIS REINFORCE’ under grant agreement no. 820846 . This work also originated in, and benefited from, discussions with multiple research and non-governmental organisations. We acknowledge and thank all involved in helping us develop and refine our ideas. We also thank two anonymous referees who provided valuable and insights comments that significantly helped in improving the original manuscript. We also grateful for the constructive and thoughtful comments provided by two anonymous referees

    Irradiation control of the "SPIRAL" target by measuring the ion beam intensity via a fast current transformer

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    International audienceIn order to obtain a more precise control on the irradiation of the targets of the "SPIRAL" installation, a new criterion of safety must be respected. To control this latter, an AQ system has been put in operation and more specifically a new device has been set up in order to measure the ion beam intensity and to calculate the number of particules per second. This value can then be integrated over time. This device consists of two Fast Current Transformers integrated in a mechanical unit placed in a vacuum chamber. These sensors reproduce the image of the pulsed beam at 10MHz and we take from the amplified signal of each sensor, the amplitude of the 2nd harmonic. Each one of these amplitudes is detected by a Lock-in Amplifier, which is acquired via a real time industrial controller. The intensity is calculated by the Fourier series relation between the amplitude of the 2nd harmonic and the average intensity. These equipments can be remotely tested by integrating a test turn on the sensors. They are redundant. The accuracy of measurement is estimated taking into account the variation of beam, of the environment and of the installatio

    THI safety system

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    International audienceFor several years, GANIL has been allowed to reach a maximum beam power of six kilowatts (400W in normal mode) thanks to the THI system (High Intensity Transport System). Three modes of running are necessary to accelerate a THI beam ("Injector" mode, "tuning" mode and "surveillance" mode). The "surveillance" mode requires a safety system to protect equipment against beam losses. Inside cyclotrons, diagnostics measure beam-loss currents at the injection and extraction devices. Along beam lines, diaphragms measure beam-loss currents at the input and output of dipoles. Current transformers are used for beam transmission measurements through beam lines and the cyclotrons. The safety system controls beam losses and quickly cuts the beam with a chopper if losses exceed thresholds. These thresholds can be seen and changed by software

    Resolution and enhancement in nanoantenna-based fluorescence microscopy

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    Single gold nanoparticles can act as nanoantennas for enhancing the fluorescence of emitters in their near-fields. Here we present experimental and theoretical studies of scanning antenna-based fluorescence microscopy as a function of the diameter of the gold nanoparticle. We examine the interplay between fluorescence enhancement and spatial resolution and discuss the requirements for deciphering single molecules in a dense sample. Resolutions better than 20 nm and fluorescence enhancement up to 30 times are demonstrated experimentally. By accounting for the tip shaft and the sample interface in finite-difference time-domain calculations, we explain why the measured fluorescence enhancements are higher in the presence of an interface than the values predicted for a homogeneous environment.Comment: 10 pages, 3 figures. accepted for publication in Nano Letter

    Recent developments for beam intensity increase operation

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    International audienceThe aim of the beam intensity increase operation (THI project) is to multiply the present intensities for lightest ions by a factor of fifteen in order to reach maximum power of six kilowatts [1]. The main objective is the production of large amounts of rare isotopes, either with SISSI (device intended for producing radioactive beams), or with SPIRAL (production and acceleration of radioactive ion beams). As part of this THI project, new developments have been required such as spiral scanners, for beanl profile measurements, and safety system to protect equipments against beam losses. Other developments are being carried on to improve the high intensity beam operation

    RESEARCH REAGRDING ACID SOILS IMPROVEMENT USING A WASTE FROM METALLURGY

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    The soil reaction value depend on the soil percentage base saturation degree and of the saturation type (predominantly with calcium or sodium). At the same time, the soil moisture regime, percolative or periodically percolative, the long application of nitrogen fertilizers, acid pollution, determine the deep leaching of bases. So, the upper part of soil suffers an acidification process especially under the conditions without liming. Generally, soil pH values less than 5,5 ensure conditions for strong solubilization of pollutants and their translocation into plants. Particular problems are raised by the very strongly and strongly acid soils (0,60% and 6,57%, respectively), some of the being specific for the mountainous pastures. In Romania are 1 867 000 ha acid agricultural land, representing over 12% from the total agricultural surface of the country. On the other hand, in Romania are produced annually from 0.18 to 0.2 million tones ladle slag (LF slag) from steel refinery, classified as a dangerous waste due to its alkalinity (alkalinity index 3.5-4.5)
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