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New neutron transmission data at resonance energies using a $$^{197}$$ 197 Au sample were measured using an early version of the Device for Indirect Capture Experiments on Radionuclides (DICER), which is under development at the Los Alamos Neutron Science Center (LANSCE). These data were combined with previous neutron transmission and capture data in a simultaneous R-matrix analysis to extract improved neutron resonance parameters for this nuclide. As a result, total radiation widths, $$\varGamma _{\gamma }$$ Γ γ , were obtained for 33 $$J=1$$ J = 1 and 44 $$J=2$$ J = 2 $$^{197}$$ 197 Au+n resonances. $$\varGamma _{\gamma }$$ Γ γ distributions for these two spins states were compared to distributions calculated according to the nuclear statistical model using published nuclear level density (NLD) and photon strength functions (PSF) measured using the Oslo technique. The calculated distributions were found to be narrower and the average values for the two spins states closer together than the data. The calculation can be brought into agreement with the data by substantial modifications to the spin distribution in $$^{198}$$ 198 Au as a function of excitation energy. As far as we know, the spin distribution currently is otherwise poorly constrained. The modified spin distribution changes the shapes of the NLD and PSF extracted using the Oslo technique and so could have broad implications.

The ion exchange of α-zirconium phosphate (ZrP) nanoparticles, highly crystalline zirconium phosphates prepared by the hydrothermal method, and epoxide functionalized zirconium phosphates were investigated. A series of exchange reactions involving both the surface and interlayer were used to determine exchange capacities for each environment and investigate the relationship between the interlayer and surface phosphates of ZrP. The resulting relationship was used to develop a new methodology to determine the average particle thickness within a sample of ZrP. Upon functionalization, the exchange capacities of derivatives prepared by surface functionalization (SF) and full functionalization (FF) were compared to the pristine ZrP, and an additional method was developed to determine the degree of functionalization in each sample.

Two dimensional (2D) nanostructured α-zirconium phosphate (ZrP) was studied for its effects on lubrication. Tribological characterization revealed that these nanoplatelets were effective as lubricant additives in both non-aqueous and aqueous media. Friction was reduced as much as by 65% and 91%, respectively in mineral oil and water when they were added. Two mechanisms of friction were proposed: viscosity modification and intermolecular interaction. This research has uncovered a novel approach for minimizing energy loss by friction reduction and should benefit many sectors such as manufacturing and consumer automobiles. Additionally, a clear understanding of properties-performance relationship of 2D nanoparticles would enable innovative design of novel materials for a variety of end uses.

A search for the neutron-unbound nucleus $^{21}$C was performed via the single proton removal reaction from a beam of 22 N at 68 MeV/u. Neutrons were detected with the Modular Neutron Array (MoNA) in coincidence with $^{20}$C fragments. No evidence for a low-lying state was found, and the reconstructed $^{20}$C+n decay energy spectrum could be described with an s-wave line shape with a scattering length limit of |as| < 2.8 fm, consistent with shell model predictions. A comparison with a renormalized zero-range three-body model suggests that $^{22}$C is bound by less than 70 keV., Accepted for publication in Nuclear Physics A

Objectives. Body weight-supported treadmill training (BWSTT) is a task-specific rehabilitation strategy that enhances functional locomotion in patients following spinal cord injury (SCI). Supraspinal centers may play an important role in the recovery of over-ground locomotor function in patients with motor-incomplete SCI. The purpose of this study was to evaluate the potential for supraspinal reorganization associated with 12 weeks of robotic BWSTT using functional magnetic resonance imaging (fMRI). Methods. Four men with motor-incomplete SCI participated in this study. Time since onset ranged from 14 weeks to 48 months post-SCI injury. All subjects were trained with BWSTT 3 times weekly for 12 weeks. This training was preceded and followed by fMRI study of supraspinal activity during a movement task. Testing of locomotor disability included the Walking Index for Spinal Cord Injury (WISCI II) and over-ground gait speed. Results. All subjects demonstrated some degree of change in the blood-oxygen-level-dependent (BOLD) signal following BWSTT. fMRI results demonstrated greater activation in sensorimotor cortical regions (S1, S2) and cerebellar regions following BWSTT. Conclusions. Intensive task-specific rehabilitative training, such as robotic BWSTT, can promote supraspinal plasticity in the motor centers known to be involved in locomotion. Furthermore, improvement in over-ground locomotion is accompanied by an increased activation of the cerebellum.

The neutron-unbound nucleus ${}^{15}$Be was observed for the first time. It was populated using neutron transfer from a deuterated polyethylene target with a 59 MeV/u ${}^{14}$Be beam. Neutrons were measured in coincidence with outgoing ${}^{14}$Be particles and the reconstructed decay energy spectrum exhibits a resonance at 1.8(1) MeV. This corresponds to ${}^{15}$Be being unbound by 0.45 MeV more then ${}^{16}$Be thus significantly hindering the sequential two-neutron decay of ${}^{16}$Be to ${}^{14}$Be through this state.

Proton removal reactions from a secondary 22N beam were utilized to populate unbound states in neutron-rich carbon isotopes. Neutrons were measured with the Modular Neutron Array (MoNA) in coincidence with carbon fragments. A resonance with a decay energy of 76(14) keV was observed in the system 18C+n corresponding to a state in 19C at an excitation energy of 653(95)keV. This resonance could correspond to the first 5/2+ state which was recently speculated to be unbound in order to describe 1n and 2n removal cross section measurements from 20C., Comment: accepted for publication in Nucl. Phys. A

High conversion efficiency and selectivity are the two primary attractive features of electrochemical processes, in particular those using high temperature ion selective membranes. By selectively removing specific ionic species, the radicals that are created will react to form new compounds. Oxygen ion conductors are commonly used to remove oxygen from oxidized species thus creating molecules with fuel value. Judicious selection of materials set and device operating conditions are required to achieve desired product formation. The electrocatalytic layers on the electrochemical cells perform two functions, that of a catalyst and as an electrical conductor. Appropriate choice of electrode materials is required for stable performance and to avoid unwanted product formation. Control of operating conditions, namely temperature, fraction converted, and driving potential also is critical to achieve the selectivity. Ceramatec is currently developing electrochemical technologies using zirconia membrane based electrolysis devices for multiple applications. One is the production of fuels such as hydrogen from steam and syngas from a mixture of steam and carbon dioxide. The product can be used as gaseous fuel or further converted to liquid fuels using conventional chemical processes. The process enables highly efficient conversion and storage of intermittent wind and solar energy in the form of energy dense liquid fuels. The second application involves electrolysis of carbon dioxide of Mars atmosphere to produce CO and oxygen for fuel synthesis and life support for future manned mission. A third application is to develop deoxygenation technology to remove oxygen from liquid hydrocarbon compounds produced from biomass to increase its fuel properties. The requirements of each of these applications are varied and necessitate different operating conditions and significant changes to conventional electrode materials developed for high temperature fuel cell applications. An overview of these technical challenges and approach to addressing them will be presented.

The ground state of $^{28}$F has been observed as an unbound resonance $2\underline{2}0$ keV above the ground state of $^{27}$F. Comparison of this result with USDA/USDB shell model predictions leads to the conclusion that the $^{28}$F ground state is primarily dominated by $sd$-shell configurations. Here we present a detailed report on the experiment in which the ground state resonance of $^{28}$F was first observed. Additionally, we report the first observation of a neutron-unbound excited state in $^{27}$F at an excitation energy of $25\underline{0}0 (2\underline{2}0)$ keV., 10 pages, 11 figures, Accepted for publication in Phys. Rev. C

Background: Momentum distributions of fragmentation products as a function of fragment mass have been used to study the fragmentation mechanism. The parallel component of the momentum distribution has been well studied previously and modeled. The perpendicular component, however, is much less measured or understood.Purpose: Measure both components of the linear momentum of a wide range of fragmentation products and compare the widths of the momentum distributions to previous results and descriptions.Method: The parallel and perpendicular components of the momentum vector have been measured for projectile-like fragments produced in the reactions of ${}^{76}$Ge with ${}^{9}$Be and ${}^{197}\phantom{\rule{-0.16em}{0ex}}$Au at 130 MeV/nucleon in a magnetic spectrometer.Results: The measured parallel momentum distributions of all fragments follow established systematics. The perpendicular momentum distributions of fragments produced by fragmentation by the ${}^{197}\phantom{\rule{-0.16em}{0ex}}$Au target with masses near that of the projectile exhibit a clear peak near the momentum corresponding to the grazing angle that diminishes with decreasing fragment mass.Conclusions: The interplay between Coulomb and nuclear scattering can be used to describe results for the most peripheral collisions.

The technique of invariant mass spectroscopy has been used to measure, for the first time, the ground state energy of neutron-unbound $^{28}\textrm{F},$ determined to be a resonance in the $^{27}\textrm{F} + n$ continuum at $2\underline{2}0 (\underline{5}0)$ keV. States in $^{28}\textrm{F}$ were populated by the reactions of a 62 MeV/u $^{29}\textrm{Ne}$ beam impinging on a 288 $\textrm{mg/cm}^2$ beryllium target. The measured $^{28}\textrm{F}$ ground state energy is in good agreement with USDA/USDB shell model predictions, indicating that $pf$ shell intruder configurations play only a small role in the ground state structure of $^{28}\textrm{F}$ and establishing a low-$Z$ boundary of the island of inversion for N=19 isotones., Comment: 5 pages, 4 figures, to be published in Phys. Rev. Lett

To develop and test a clinically relevant model for predicting the recovery of over ground walking speed after 36 sessions of progressive body weight-supported treadmill training (BWSTT) in individuals with motor incomplete spinal cord injury (SCI).A retrospective review and stepwise regression analysis of a SCI clinical outcomes data set.Outpatient SCI laboratory.Thirty individuals with a motor incomplete SCI who had participated in locomotor training with BWSTT. Eight individuals with similar diagnoses were used to prospectively test the prediction model.Over ground walking speed was assessed using the 10-m walking test.The locomotor training program consisted of 36 sessions of sequential comprehensive training comprised of robotic assisted BWSTT, followed by manual assisted BWSTT, and over ground walking. The dose of locomotor training was standardized throughout the protocol.Clinical characteristics with predictive value for walking speed were time from injury onset, the presence or absence of voluntary bowel and bladder voiding, a functional spasticity assessment, and over ground walking speed before locomotor training. The model identified that these characteristics accounted for 78.3% of the variability in the actual final over ground walking speed after 36 sessions of locomotor training. The model was successful in prospectively predicting over ground walking speed in the 8 test participants within 4.15 +/- 2.22 cm/s in their recovered walking speed.This prediction model can identify individuals who are most likely to experience success using locomotor training by determining an expected magnitude of training effect, thereby allowing individualized decisions regarding the use of this intensive approach to rehabilitation.

Two new experiments were carried out at the NSCL to explore the details of the linear moment and excitation energy distributions of projectile fragmentation production. In the first experiment the full linear momentum distributions of fragments from the reaction of a 76 Ge beam with beryllium and gold targets were measured in the S800 spectrometer. The results indicate a strong contribution of "far side" or attractive scattering to the near-projectile products with the gold target. In the second experiment the excitation energy of primary projectile fragments from peripheral nuclear reactions at intermediate energies was carried out at the NSCL. Sodium, neon and fluorine isotopes produced by the fragmentation of a neutron-rich 32Mg beam by a beryllium target were observed in a magnetic spectrometer in coincidence with fast neutrons detected using the Modular Neutron Array (MoNA). A new technique based on an analysis of the observed neutron multiplicity distributions was used to estimate the excitation energy and mass of the precursor intermediate products for the first time. A strong correlation between the neutron multiplicity and the total mass loss was observed indicating that large excitation energies were created in the prefragments by the initial collision. These findings are generally consistent with the internuclear cascade model of the collision dynamics but not with macroscopic abrasion-ablation models.

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The fatty acid composition of the stomach contents, adipose tissue, and perinephric fat of Polynesian rats (Rattus exulans Peale), from the Tokelau Is indicated that the dietary fat consisted mainly, if not exclusively, of coconut oil. Lower ratios of lauric : myristic acids were found in the depot fats of the Polynesian rats than in the dietary coconut oil. These results were consistent with chain elongation of lauric to myristic acid after ingestion, as previously reported in rats and other mammals.