Crystallization by particle attachment is impacting our understanding of natural mineralization processes and holds promise for novel materials design. When particles assemble in crystallographic ...alignment, expulsion of the intervening solvent and particle coalescence are enabled by near-perfect co-alignment via interparticle forces that remain poorly quantified. Here we report measurement and simulation of these nanoscale aligning forces for the ZnO(0001)-ZnO(000Formula: see text) system in aqueous solution. Dynamic force spectroscopy using nanoengineered single crystal probes reveals an attractive force with 60
rotational periodicity. Calculated distance and orientation-dependent potentials of mean force show several attractive free energy wells distinguished by numbers of intervening water layers, which reach a minimum when aligned. The calculated activation energy to separate the attractively bound solvated interfaces perfectly reproduces the measured 60
periodicity, revealing the key role of intervening water structuring as a basis to generate the interparticle torque that completes alignment and enables coalescence.Crystal growth is a fundamental process, important in a wide range of fields, but the interparticle forces responsible for molecule alignment are not well understood. Here, the authors measure the alignment forces in ZnO using dynamic force spectroscopy, highlighting the role of intervening water molecules.
PROSPECT, the Precision Reactor Oscillation and Spectrum Experiment, is an effort to resolve anomalous results observed in previous neutrino physics experiments. The primary physics goals of PROSPECT ...are to perform a search for short baseline neutrino oscillations (Δm 2 ∼ 1eV2) and to make a high precision measurement of the 235U reactor antineutrino energy spectrum. PROSPECT will operate close to the Oak Ridge National Laboratory's High Flux Isotope Reactor, where very little cosmic-ray attenuating overburden is available. To make precision measurements in this difficult environment, PROSPECT has developed a segmented detector design using a 6Li-doped liquid scintillator which provides excellent energy resolution and background rejection.
We present a detailed report on sterile neutrino oscillation and 235Uν¯e energy spectrum measurement results from the PROSPECT experiment at the highly enriched High Flux Isotope Reactor (HFIR) at ...Oak Ridge National Laboratory. In 96 calendar days of data taken at an average baseline distance of 7.9 m from the center of the 85 MW HFIR core, the PROSPECT detector has observed more than 50,000 interactions of νe produced in beta decays of 235U fission products. New limits on the oscillation of ν¯e to light sterile neutrinos have been set by comparing the detected energy spectra of ten reactor-detector baselines between 6.7 and 9.2 meters. Measured differences in energy spectra between baselines show no statistically significant indication of ν¯e to sterile neutrino oscillation and disfavor the reactor antineutrino anomaly best-fit point at the 2.5σ confidence level. The reported 235U ν¯e energy spectrum measurement shows excellent agreement with energy spectrum models generated via conversion of the measured 235U beta spectrum, with a χ2/d.o.f. of 31/31. PROSPECT is able to disfavor at 2.4σ confidence level the hypothesis that 235U ν¯e are solely responsible for spectrum discrepancies between model and data obtained at commercial reactor cores. A data-model deviation in PROSPECT similar to that observed by commercial core experiments is preferred with respect to no observed deviation, at a 2.2σ confidence level.
We report on several features in the energy spectrum from an ultralow-noise germanium detector operated deep underground. By implementing a new technique able to reject surface events, a number of ...cosmogenic peaks can be observed for the first time. We discuss an irreducible excess of bulklike events below 3 keV in ionization energy. These could be caused by unknown backgrounds, but also dark matter interactions consistent with DAMA/LIBRA. It is not yet possible to determine their origin. Improved constraints are placed on a cosmological origin for the DAMA/LIBRA effect.
The study assessed the efficacy and safety of risperidone as an adjunctive agent to mood stabilizers in the treatment of acute mania.
This 3-week randomized, double-blind, placebo-controlled study ...included 156 bipolar disorder patients with a current manic or mixed episode who received a mood stabilizer (lithium or divalproex) and placebo, risperidone, or haloperidol. The primary efficacy measure was the Young Mania Rating Scale. Other assessments used the Brief Psychiatric Rating Scale, the Clinical Global Impression scale, and safety measures.
The trial was discontinued by 25 (49%) of the 51 placebo group patients, 18 (35%) of the 52 risperidone group patients, and 28 (53%) of the 53 haloperidol group patients. Mean modal doses were 3.8 mg/day (SD=1.8) of risperidone and 6.2 mg/day (SD=2.9) of haloperidol. Significantly greater reductions in Young Mania Rating Scale scores at endpoint and over time were seen in the risperidone group and in the haloperidol group, compared with the placebo group. Young Mania Rating Scale total scores improved with risperidone and with haloperidol both in patients with psychotic features and in those without psychotic features at baseline. Extrapyramidal Symptom Rating Scale total scores at endpoint were significantly higher in the haloperidol patients than in the placebo patients. Antiparkinsonian medications were received by 8%, 17%, and 38% of patients in the placebo, risperidone, and haloperidol groups, respectively.
Risperidone plus a mood stabilizer was more efficacious than a mood stabilizer alone, and as efficacious as haloperidol plus a mood stabilizer, for the rapid control of manic symptoms and was well tolerated.
Shear Assisted Processing and Extrusion (ShAPE) -a novel processing route that combines high shear and extrusion conditions- was evaluated as a processing method to densify melt spun magnesium alloy ...(AZ91E) flake materials. This study illustrates the microstructural regimes and transitions in crystallographic texture that occur as a result of applying simultaneous linear and rotational shear during extrusion. Characterization of the flake precursor and extruded tube was performed using scanning and transmission electron microscopy, x-ray diffraction and microindentation techniques. Results show a unique transition in the orientation of basal texture development. Despite the high temperatures involved during processing, uniform grain refinement and material homogenization are observed. These results forecast the ability to implement the ShAPE processing approach for a broader range of materials with novel microstructures and high performance.
PROSPECT is a reactor antineutrino experiment whose primary goals are to search for short-baseline neutrino oscillations and perform a precise measurement of the
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U reactor antineutrino energy ...spectrum. Since March 2018, PROSPECT has operated a 4 ton antineutrino detector less than 10 m from the 85 MW High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory. Operating in this environment with tight space constraints and limited overburden to attenuate cosmic ray backgrounds is a significant technical challenge. The PROSPECT detector design uses efficient optical segmentation and a 6Li-doped liquid scintillator with good light yield and pulse-shape discrimination properties to achieve excellent energy reconstruction and background rejection in a compact, space efficient system. Initial results from PROSPECT have demonstrated the ability to detect 100 s of antineutrino events per day with good signal-to-background in this aboveground location and perform precise measurements of the HFIR antineutrino energy spectrum.
This Letter reports the first measurement of the 235U $\bar{ν}$e energy spectrum by PROSPECT, the Precision Reactor Oscillation and Spectrum experiment, operating 7.9 m from the 85 MWth highly ...enriched uranium (HEU) High Flux Isotope Reactor. With a surface-based, segmented detector, PROSPECT has observed 31678±304(stat) $\bar{ν}$e-induced inverse beta decays, the largest sample from HEU fission to date, 99% of which are attributed to 235U. Despite broad agreement, comparison of the Huber 235U model to the measured spectrum produces a χ2/ndf=51.4/31, driven primarily by deviations in two localized energy regions. The measured 235U spectrum shape is consistent with a deviation relative to prediction equal in size to that observed at low-enriched uranium power reactors in the $\bar{ν}$e energy region of 5–7 MeV.
A background-free observation of cold antihydrogen atoms is made using field ionization followed by antiproton storage, a detection method that provides the first experimental information about ...antihydrogen atomic states. More antihydrogen atoms can be field ionized in an hour than all the antimatter atoms that have been previously reported, and the production rate per incident high energy antiproton is higher than ever observed. The high rate and the high Rydberg states suggest that the antihydrogen is formed via three-body recombination.
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