Understanding And Improving The Environmental Dependent Tribology And Thermal Stability Of Hydrogenated Amorphous Carbon By Using Silicon And Oxygen As Dopants

Hydrogenated amorphous carbon (a-C:H) films are a class of non-crystalline materials composed of hydrogen and carbon bonded in both sp2 and sp3 configurations. These films are notable for their high hardness (10–16 GPa), low roughness, chemical inertness, and good tribological performance (low friction and wear). This combination of favorable properties has led to promising applications in diverse fields, including automotive and aerospace components, biomedical devices, and computer hard drives. However, a-C:H becomes unstable above 150 °C, preventing its use in important technological applications, such as heat assisted magnetic recording (HAMR) disk drives. Also, the low friction and wear is only maintained in dry and vacuum conditions. To understand and address these limitations, the effect of adding silicon and oxygen to a-C:H films is considered, since prior experimental evidence shows that this can significantly increases thermal stability, and help maintain low friction and wear in humid environments. However, the mechanisms and extent of these improvements are unknown. Friction and wear testing were performed on a-C:H doped with Si and O (a-C:H:Si:O) in a range of environments. Friction coefficients varied from approximately 0.05 in dry environments (RH \u3c 5%) to 0.15 in humid air, better than prior observations for undoped a-C:H films. The friction and wear behavior is controlled by adhesive interactions leading to the development of transfer films on the steel counterface. Possible mechanisms underlying this behavior are discussed. Annealing experiments showed significant improvements in thermal stability up to 450 °C. In order to understand the atomistic origins of this enhanced thermal stability, reactive molecular dynamics (MD) simulations using the ReaxFF potential were performed. The primary thermal degradation pathway in undoped a-C:H was observed to be the breaking of tensile strained C-C bonds. The presence of Si suppresses this mechanism by decreasing the frequency of highly strained C-C bonds in the unannealed structure. This is due to the longer C-Si equilibrium bond length compared to C-C bonds. The activation energy for rehybridization could be modeled using the same methods as in prior experiments and produced good agreement between the experimental and simulation results

The Effects of Massage on Delayed Muscle Soreness

The purpose of this study was to investigate the physiological and psychological effects of massage on delayed onset muscle soreness (DOMS). To that end, 18 subjects were randomly assigned to a massage or control group. Prior to inducing DOMS, the following baseline measures were made: range of motion (ROM), peak hamstring torque, neutrophil count, and mood (POMS). DOMS was induced with 6 sets of 8 maximal eccentric contractions of the right hamstring. Two hours later, subjects received 20 min of massage or sham massage (control). Peak torque, POMS, neutrophil count, and intensity and unpleasantness of soreness were assessed. at 2, 6, 24, and 48 h post­ exercise. A two-factor ANOVA (treatment vs. time) with repeated measures on the second factor showed no significant treatment differences for peak hamstring torque, ROM, unpleasantness of soreness, POMS, and neutrophil count (p \u3e 0.05). However, the massage group indicated significantly lower intensity of soreness at 48 h post-exercise than the control (p \u3c 0.05). In conclusion, massage administered after DOMS-inducing exercise does not appear to reduce inflammation or improve hamstring function. Massage treatments may still be practical because our data revealed it lowered the intensity of soreness. The mechanisms for such psychological benefits require further investigation

Cosmic Shear Results from the Deep Lens Survey - II: Full Cosmological Parameter Constraints from Tomography

We present a tomographic cosmic shear study from the Deep Lens Survey (DLS), which, providing a limiting magnitude r_{lim}~27 (5 sigma), is designed as a pre-cursor Large Synoptic Survey Telescope (LSST) survey with an emphasis on depth. Using five tomographic redshift bins, we study their auto- and cross-correlations to constrain cosmological parameters. We use a luminosity-dependent nonlinear model to account for the astrophysical systematics originating from intrinsic alignments of galaxy shapes. We find that the cosmological leverage of the DLS is among the highest among existing >10 sq. deg cosmic shear surveys. Combining the DLS tomography with the 9-year results of the Wilkinson Microwave Anisotropy Probe (WMAP9) gives Omega_m=0.293_{-0.014}^{+0.012}, sigma_8=0.833_{-0.018}^{+0.011}, H_0=68.6_{-1.2}^{+1.4} km/s/Mpc, and Omega_b=0.0475+-0.0012 for LCDM, reducing the uncertainties of the WMAP9-only constraints by ~50%. When we do not assume flatness for LCDM, we obtain the curvature constraint Omega_k=-0.010_{-0.015}^{+0.013} from the DLS+WMAP9 combination, which however is not well constrained when WMAP9 is used alone. The dark energy equation of state parameter w is tightly constrained when Baryonic Acoustic Oscillation (BAO) data are added, yielding w=-1.02_{-0.09}^{+0.10} with the DLS+WMAP9+BAO joint probe. The addition of supernova constraints further tightens the parameter to w=-1.03+-0.03. Our joint constraints are fully consistent with the final Planck results and also the predictions of a LCDM universe.Comment: Accepted for publication in Ap

Perceptions of Family Preservation Practitioners: A Preliminary Study

This exploratory, qualitative study examined practitioners\u27 perceptions about family preservation practice. Findings reveal a wide range of identified strengths as well as the limitations of such a model. Interestingly, the most frequently identified strengths were value based rather than practice based in perspective whereas limitations were practice based. Keeping families together was the most common perceived strength but concern about children\u27s safety by keeping the family intact was a frequently reported limitation. Further, lack of support and a lack of theoretical clarity were identified as considerable limitations. Implications suggest these practitioners (mostly child welfare/mental health workers) believe in the approach for the sake of keeping families together but are concerned with endangering the child in the process and recognize the need for theoretical guidance

Uma nova metodologia de solução para sistemas de mancais radiais em carregamento dinâmico incluindo atrito sólido e desgaste

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia MecânicaEste trabalho discorre sobre o modelamento de mancais radiais acoplados sujeitos a carregamento dinâmico, bem como sobre sua metodologia de solução, incluindo atrito sólido e desgaste. O modelo considera o acoplamento entre dois mancais radiais de um mesmo eixo, levando em conta os deslocamentos e desalinhamentos radiais. Uma metodologia de volumes finitos é utilizada para a solução da equação de Reynolds que governa o problema de lubrificação. O desgaste e o contato direto entre as superfícies do eixo e dos mancais são tratados com o uso das leis de Archard e de Coulomb para desgaste e atrito sólido, respectivamente. O volume desgastado é removido da vizinhança do ponto de contato sólido de uma forma automática. Isto permite um cálculo preciso das geometrias do eixo e do mancal após contato e desgaste. As equações da dinâmica, do contato direto, e de Reynolds, são resolvidas em um único sistema linear de equações. O método de solução é direto, mas são necessárias iterações para contemplar a cavitação do filme de óleo e as não-linearidades das equações. O sistema linear é resolvido utilizando-se o método de eliminação de Gauss, e para otimizar o processo de solução, considera-se a esparsividade do sistema. Um programa computacional com base na formulação deste trabalho foi desenvolvido e testado utilizando-se informações da literatura. São obtidos resultados para os mancais principal e secundário de um pequeno compressor alternativo utilizado em refrigeração doméstica. A pressão do gás no topo do pistão do compressor foi artificialmente aumentada para forçar o contato sólido. Foi então observado que uma nova geometria para eixo e mancais foi gerada pelo desgaste e que o contato sólido foi eliminado. Informações como a órbita dos mancais, o consumo de potência por atritos sólido e viscoso, a vazão lateral de óleo, a espessura mínima de filme de óleo e o desgaste podem ser consistentemente obtidas pelo programa computacional que mostrou-se robusto e eficiente

Topology of the three-qubit space of entanglement types

The three-qubit space of entanglement types is the orbit space of the local unitary action on the space of three-qubit pure states, and hence describes the types of entanglement that a system of three qubits can achieve. We show that this orbit space is homeomorphic to a certain subspace of R^6, which we describe completely. We give a topologically based classification of three-qubit entanglement types, and we argue that the nontrivial topology of the three-qubit space of entanglement types forbids the existence of standard states with the convenient properties of two-qubit standard states.Comment: 9 pages, 3 figures, v2 adds a referenc

Land-use and Land-cover Change from 1974 to 2008 around Mobile Bay

This project is a Gulf of Mexico Application Pilot in which NASA Stennis Space Center (SSC) is working within a regional collaboration network of the Gulf of Mexico Alliance. NASA researchers, with support from the NASA SSC Applied Science Program Steering Committee, employed multi-temporal Landsat data to assess land-use and land-cover (LULC) changes in the coastal counties of Mobile and Baldwin, AL, between 1974 and 2008. A multi-decadal time-series, coastal LULC product unique to NASA SSC was produced. The geographic extent and nature of change was quantified for the open water, barren, upland herbaceous, non-woody wetland, upland forest, woody wetland, and urban landscapes. The National Oceanic and Atmospheric Administration (NOAA) National Coastal Development Data Center (NCDDC) will assist with the transition of the final product to the operational end user, which primarily is the Mobile Bay National Estuary Program (MBNEP). We found substantial LULC change over the 34-year study period, much more than is evident when the change occurring in the last years. Between 1974 and 2008, the upland forest landscape lost almost 6% of the total acreage, while urban land cover increased by slightly more than 3%. With exception to open water, upland forest is the dominant landscape, accounting for about 25-30% of the total area

Medication adherence in patients with myotonic dystrophy and facioscapulohumeral muscular dystrophy

Myotonic dystrophy (DM) and facioscapulohumeral muscular dystrophy (FSHD) are the two most common adult muscular dystrophies and have progressive and often disabling manifestations. Higher levels of medication adherence lead to better health outcomes, especially important to patients with DM and FSHD because of their multisystem manifestations and complexity of care. However, medication adherence has not previously been studied in a large cohort of DM type 1 (DM1), DM type 2 (DM2), and FSHD patients. The purpose of our study was to survey medication adherence and disease manifestations in patients enrolled in the NIH-supported National DM and FSHD Registry. The study was completed by 110 DM1, 49 DM2, and 193 FSHD patients. Notable comorbidities were hypertension in FSHD (44 %) and DM2 (37 %), gastroesophageal reflux disease in DM1 (24 %) and DM2 (31 %) and arrhythmias (29 %) and thyroid disease (20 %) in DM1. Each group reported high levels of adherence based on regimen complexity, medication costs, health literacy, side effect profile, and their beliefs about treatment. Only dysphagia in DM1 was reported to significantly impact medication adherence. Approximately 35 % of study patients reported polypharmacy (taking 6 or more medications). Of the patients with polypharmacy, the DM1 cohort was significantly younger (mean 55.0 years) compared to DM2 (59.0 years) and FSHD (63.2 years), and had shorter disease duration (mean 26 years) compared to FSHD (26.8 years) and DM2 (34.8 years). Future research is needed to assess techniques to ease pill swallowing in DM1 and to monitor polypharmacy and potential drug interactions in DM and FSHD

Geospatial Method for Computing Supplemental Multi-Decadal U.S. Coastal Land-Use and Land-Cover Classification Products, Using Landsat Data and C-CAP Products

This paper discusses the development and implementation of a geospatial data processing method and multi-decadal Landsat time series for computing general coastal U.S. land-use and land-cover (LULC) classifications and change products consisting of seven classes (water, barren, upland herbaceous, non-woody wetland, woody upland, woody wetland, and urban). Use of this approach extends the observational period of the NOAA-generated Coastal Change and Analysis Program (C-CAP) products by almost two decades, assuming the availability of one cloud free Landsat scene from any season for each targeted year. The Mobile Bay region in Alabama was used as a study area to develop, demonstrate, and validate the method that was applied to derive LULC products for nine dates at approximate five year intervals across a 34-year time span, using single dates of data for each classification in which forests were either leaf-on, leaf-off, or mixed senescent conditions. Classifications were computed and refined using decision rules in conjunction with unsupervised classification of Landsat data and C-CAP value-added products. Each classification's overall accuracy was assessed by comparing stratified random locations to available reference data, including higher spatial resolution satellite and aerial imagery, field survey data, and raw Landsat RGBs. Overall classification accuracies ranged from 83 to 91% with overall Kappa statistics ranging from 0.78 to 0.89. The accuracies are comparable to those from similar, generalized LULC products derived from C-CAP data. The Landsat MSS-based LULC product accuracies are similar to those from Landsat TM or ETM+ data. Accurate classifications were computed for all nine dates, yielding effective results regardless of season. This classification method yielded products that were used to compute LULC change products via additive GIS overlay techniques