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Purpose Little is known of the potential long term gait alterations that occur after an anterior cruciate ligament (ACL) reconstruction. In particular, variables such as impact loading which have been previously associated with joint deterioration have not been studied in walking and running after an ACL reconstruction. The purpose of this study was to define the alterations in impact forces, loading rates, and the accompanying sagittal plane kinematic and kinetic mechanics at the time of impact between the ACL reconstructed group and a healthy control group. Methods 40 females (20 ACL reconstruction, 20 controls) participated in the study. An instrumented gait analysis was performed on all subjects. Between group and limb comparisons were made for initial vertical impact force, loading rate, sagittal plane knee and hip angles as well as moments. Results During walking and running the ACL cohort had significantly greater initial vertical impact force (p=0.002 and p= 0.001), and loading rates (p=0.03 and p= 0.01), as well as a smaller knee extensor moment and hip angle during walking (p=0.000 and p=0.01). There was a trend towards a smaller knee moment and hip angle during running (p=0.08 and p=0.06) as well as a larger hip extensor moment during walking (p=0.06) in the ACL group. No differences were found for hip extensor moment during running, knee angles between groups during walking or running. Lastly, no between limb differences were found for any variable. Conclusion Gait deviations such as elevated impact loading and loading rates do not resolve long term after the individual has resumed previous activity levels and may contribute to the greater risk of early joint degeneration in this population.

This work aims to understand how effective the typical admissions criteria used in physics are at identifying students who will complete the PhD. Through a multivariate statistical analysis of a sample that includes roughly one in eight students who entered physics PhD programs from 2000-2010, we find that the traditional admissions metrics of undergraduate GPA and the Graduate Records Examination (GRE) Quantitative, Verbal, and Physics Subject Tests do not predict completion in US physics graduate programs with the efficacy often assumed by admissions committees. We find only undergraduate GPA to have a statistically significant association with physics PhD completion across all models studied. In no model did GRE Physics or GRE Verbal predict PhD completion. GRE Quantitative scores had statistically significant relationships with PhD completion in two of four models studied. However, in practice, probability of completing the PhD changed by less than 10 percentage points for students scoring in the 10 vs 90 percentile of US test takers that were physics majors. Noting the significant race, gender, and citizenship gaps in GRE scores, these findings indicate that the heavy reliance on these test scores within typical PhD admissions process is a deterrent to increasing access, diversity, and equity in physics. Misuse of GRE scores selects against already-underrepresented groups and US citizens with tools that fail to meaningfully predict PhD completion. This is a draft; see the journal for the published version.Additionally included in blue text are several responses to queries about this work.

The net tunneling conductance of metal-insulator-metal tunnel junctions is studied using a distribution of barrier thicknesses consistent with interfacial roughness typical of state-of-the-art tunnel junctions. Moderate amounts of roughness cause the conductance to resemble that of much thinner and taller barriers. Fitting numerically generated conductance data that include roughness with models that assume a single-thickness barrier leads to erroneous results for both the barrier height and width. Rules of thumb are given that connect the roughness to the real space mean thickness and the thickness inferred from fitting the net conductance with traditional tunneling models.

The SUPREX thin film refinement of x-ray diffraction ͑XRD͒ was used to quantitatively analyze the structure of thermally evaporated iron phthalocyanine ͑FePc͒ organic thin films as a function of growth temperature and postdeposition in situ annealing time. A bilayer model was necessary to refine the FePc XRD data. Results using this model provide clear evidence that the first molecular layer of FePc contacting the sapphire substrate differs from the subsequent uniformly spaced molecular layers, indicating a Stranski-Krastanov growth mode. The ␣-to-␤ structural phase transformation of FePc was observed as a function of substrate temperature. No significant effect of postdeposition in situ annealing time was observed. Atomic force microscopy ͑AFM͒ measurements reveal a temperature-dependent morphology as the FePc changes from grains, to extended films, and finally shows crystallite formation for increasing deposition temperature. Structural characteristics obtained by SUPREX refinement and AFM quantitatively agree for surface roughness and average molecular layer spacing.

The critical temperature and saturation magnetization for four- and five-component FCC transition metal alloys are predicted using a formalism that combines density functional theory and a magnetic mean-field model. Our theoretical results are in excellent agreement with experimental data presented in both this work and in the literature. The generality and power of this approach allow us to computationally design alloys with well-defined magnetic properties. Among other alloys, the method is applied to CoCrFeNiPd alloys, which have attracted attention recently for potential magnetic applications. The computational framework is able to predict the experimentally measured TC and to explore the dominant mechanisms for alloying trends with Pd. A wide range of ferromagnetic properties and Curie temperatures near room temperature in hitherto unexplored alloys is predicted in which Pd is replaced in varying degrees by, e.g., Ag, Au, and Cu.

This review focuses on the magnetocaloric effect with special attention to nanoscale thin films and heterostructures. The authors outline the general phenomenon of the magnetocaloric effect and discuss how using materials in reduced dimensions can impact this emerging area. The authors note works of significance to date and highlight general features emanating from the community. They provide important details related to sample fabrication, relevant metrology, and discuss advanced data analyses, all of which are done in a tutorial fashion. Finally, the authors provide an outlook for the application of nanoscience to magnetocalorics.

The equimolar alloy FeCoCrNi, a high-entropy alloy, forms in the face-centered-cubic crystal structure and has a ferromagnetic Curie temperature of 130 K. In this study, we explore the effects of Cr concentration, cold-rolling, and subsequent heat treatments on the magnetic properties of FeCoCrxNi alloys. Cr reductions result in an increase of the Curie temperature, and may be used to tune the TC over a very large temperature range. The magnetic entropy change for a change in applied field of 2T is ΔSm = −0.35 J/(kg K) for cold-rolled FeCoCrNi. Cold-rolling results in a broadening of ΔSm, where subsequent heat treatment at 1073 K sharpens the magnetic entropy curve. In all of the alloys, we find that upon heating (after cold-rolling) there is a re-entrant magnetic moment near 730 K. This feature is much less pronounced in the as-cast samples (without cold-rolling) and in the Cr-rich samples, and is no longer observed after annealing at 1073 K. Possible origins of this behavior are discussed.