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Scale Structure (scale + structure)
Selected AbstractsPsychometric properties of the Pediatric Motor Activity Log used for children with cerebral palsyDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 3 2009MARGARET WALLEN MA BAPPSC(OT) The Pediatric Motor Activity Log (PMAL) is a parent-report measure of the use, by children with hemiplegic cerebral palsy (CP), of their affected upper limb in everyday activities. The aim of this study was to examine the psychometric properties of both scales of the PMAL (,How Often' and ,How Well' scales) using Rasch measurement modelling. Sixty-one parents of children with hemiplegic CP completed the PMAL and 31 completed it again 3 weeks later. The mean age of children was 4 years 6 months (SD 1y 9mo); 35 males, 26 females. Children were at Gross Motor Function Classification System (GMFCS) levels I (83%) and II (17%), and Manual Ability Classification System levels I (35%), II (52%), and III (14%). The original scales were found to have disordered rating scale structure. Further Rasch modelling with collapsed rating scale structures resulted in both scales conforming to the expectations of the Rasch model, yielding strong evidence for construct validity and reliability. One item from the How Often scale failed to conform to Rasch expectations and was deleted in subsequent analyses. Test,retest reliability of both scales was high (the intraclass correlation coefficient for the How Often scale was 0.94, and for the How Well scale 0.93). The revised scales possess good psychometric properties, specifically a logical item hierarchy, evidence of unidimensionality, adequate rating scale structure, and good test,retest reliability. We conclude that the revised PMAL has the capacity to yield valid and reliable scores except for children at the extremes of upper limb ability. [source] Relating the Functional Properties of an Organic Semiconductor to Molecular Structure by nc-AFMADVANCED MATERIALS, Issue 20 2009Sarah A. Burke The structure and properties of different molecular scale PTCDA arrangements are investigated by noncontact-AFM. A hybrid optical,electrostatic characterization is used to locally probe freely grown and nanoconfined structures in order to connect opto-electronic properties with the molecular scale structure determined by high resolution AFM. [source] Preparation and characterization of biodegradable waterabsorbent PAN/SS nanocompositePOLYMER COMPOSITES, Issue 11 2008Bijayashree Samal Polyacrylonitrile (PAN)/sodium silicate (SS) nanocomposite was prepared via nonconventional emulsion method using an in situ developed transition metal complex Cu(II)/glycine taking ammonium persulfate (APS) as initiator, with a novel motive of converting hydrophobic homopolymer PAN into hydrophilic nano material via nanotechnology by the inclusion of SS to the homopolymer. UV,visible spectral analysis was carried out which revealed various interactions between the in situ developed complex with other reaction components. The formation of the PAN/SS nanocomposite was confirmed by infrared spectra (IR). Furthermore, as evidenced by transmission electron microscopy (TEM), the composite so obtained was found to have nano scale structure. X-ray diffraction (XRD) was carried out suggesting that the silicate layers were exfoliated during the polymerization process. An increase in the thermal stability for the developed nanocomposite was recorded by thermogravimetric analysis (TGA). Surprisingly, it was also found that the PAN/SS nanocomposite showed considerable amount of waterabsorbency and was biodegradable as tested by activated sludge and cultured media and further confirmed by scanning electron microscopy (SEM). POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers [source] Parsec-scale jet in the distant gigahertz-peaked spectrum quasar PKS 0858,279ASTRONOMISCHE NACHRICHTEN, Issue 2-3 2009Y. Y. KovalevArticle first published online: 13 FEB 200 Abstract The high redshift GPS quasar PKS 0858,279 exhibits the following properties which make the source unusual. Our RATAN-600 monitoring of 1,22 GHz spectrum has detected broad-band radio variability with high amplitude and relatively short time scale. In the same time, the milliarcsecond scale structure observed in a snapshot VLBA survey turned out to be very resolved which is not expected from the fast flux density variations. We performed 1.4,22 GHz VLBA observations of this quasar in 2005,2007. It has revealed a core-jet morphology. A high Doppler factor , is suggested for the jet, its nature is discussed in this report on the basis of the multi-frequency VLBA and RATAN data collected. Synchrotron self-absorption was confirmed to be dominating at low frequencies, the magnetic field strength of the dominating jet feature is estimated of an order of 0.1, mG (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Ultra-cool and extra-vigorous: Rotation and activity in Mand L dwarfsASTRONOMISCHE NACHRICHTEN, Issue 10 2007A. Reiners, Article first published online: 27 DEC 200 Abstract The study of rotation and activity in low-mass stars or brown dwarfs of spectral classes M and L has seen enormous progress during the last years. I summarize the results from different works that measured activity, rotation, and sometimes magnetic fields. The generation of magnetic activity seems to be unchanged at the threshold to completely convective stars, i.e. no change in the efficiency of the magnetic dynamos is observed. On the other hand, a sudden change in the strength of rotational braking appears at the threshold mass to full convection, and strong evidence exists for rotational braking weakening with lower mass. A probable explanation is that the field topology changes from dipolar to small scale structure as the objects become fully convective. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Protoclusters associated with distant radio galaxiesASTRONOMISCHE NACHRICHTEN, Issue 2-3 2006B. P. Venemans Abstract The results of a large program conducted with the Very Large Telescope and the Keck telescope to search for forming clusters of galaxies near powerful radio galaxies at 2 < z < 5.2 are presented. Deep narrow- and broad-band images of eight radio galaxies and their surroundings were obtained. In the images a total of 335 candidate Ly, emitting galaxies at the redshift of the radio galaxies were selected. Subsequently, follow-up spectroscopy was performed to obtain redshifts for the candidate Ly, emitters. In at least six of eight fields (75%) an overdensity of Ly, emitters is found near the radio galaxy. Taken together with a significant clustering in redshift space of the emitters, we argue that we have discovered six forming clusters of galaxies (protoclusters). Based on the estimated masses and the volume density, we conclude that the observed structures are the likely progenitors of present-day massive (,1015 M,) clusters of galaxies. Finally, we compare the observed galaxy overdensities with numerical simulations of the development of large scale structure in the Universe. The preliminary results of this comparison provide strong additional evidence for the hypothesis that the radio galaxy protoclusters are forming massive clusters. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Probing small scale structure in the atmosphere of V471 TauriASTRONOMISCHE NACHRICHTEN, Issue 3 2004F. M. Walter Abstract The white dwarf in the eclipsing binary system V471 Tau is viewed through the atmosphere of the active K star prior to ingress and after egress. In the far UV the surface brightness of the hot white dwarf far outshines the K star emission. We can use this to probe the structure of the extended K star atmosphere along one line of sight, in absorption, on spatial scales of the radius of the white dwarf (10,000 km). The time series of HST/STIS spectra which show a hot (>250,000 K) extended (>1 K star radius) atmosphere around the K star. We see discrete structures in the velocity-resolved spectra, on spatial scales of less than 100,000 km. The mean velocity is that expected of gas in co-rotation with the K star, but the discrete velocity structures have excursions of up to 70 km/s from the mean. The mean temperature seems to increase with height above the K star photosphere. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Inside Management Teams: Developing a Teamwork Survey InstrumentBRITISH JOURNAL OF MANAGEMENT, Issue 2 2007Barbara Senior This article reports the development of a measure of teamwork for use with management teams. A five-stage process was followed. First, a model of teamwork including team processes was generated through empirical research involving the elicitation of 600 team performance constructs from members of management teams and from theoretical considerations. Second, items were written to operationalize the model. Third, data from 220 members of management teams working in private- and public-sector organizations were factor analysed in order to establish the scale structure of the instrument. Fourth, data from a second sample of 16 complete management teams were collected in order to assess within-team properties of the instrument. Lastly, convergent and criterion-related validity were assessed. The resulting ,Teamwork Survey', is a 7-scale, 36-item general-purpose questionnaire that can be used in further research and in consulting interventions. [source] A novel scale for measuring mixed states in bipolar disorderCLINICAL PSYCHOLOGY AND PSYCHOTHERAPY (AN INTERNATIONAL JOURNAL OF THEORY & PRACTICE), Issue 6 2009Jonathan Cavanagh Abstract Objectives: Conventional descriptions of bipolar disorder tend to treat the mixed state as something of an afterthought. There is no scale that specifically measures the phenomena of the mixed state. This study aimed to test a novel scale for mixed state in a clinical and community population of bipolar patients. Methods: The scale included clinically relevant symptoms of both mania and depression in a bivariate scale. Recovered respondents were asked to recall their last manic episode. The scale allowed endorsement of one or more of the manic and depressive symptoms. Internal consistency analyses were carried out using Cronbach alpha. Factor analysis was carried out using a standard Principal Components Analysis followed by Varimax Rotation. A confirmatory factor analytic method was used to validate the scale structure in a representative clinical sample. Results: The reliability analysis gave a Cronbach alpha value of 0.950, with a range of corrected-item-total-scale correlations from 0.546 (weight change) to 0.830 (mood). The factor analysis revealed a two-factor solution for the manic and depressed items which accounted for 61.2% of the variance in the data. Factor 1 represented physical activity, verbal activity, thought processes and mood. Factor 2 represented eating habits, weight change, passage of time and pain sensitivity. Conclusions: This novel scale appears to capture the key features of mixed states. The two-factor solution fits well with previous models of bipolar disorder and concurs with the view that mixed states may be more than the sum of their parts. Copyright © 2009 John Wiley & Sons, Ltd. Key Practitioner Message: There is no clinical scale that specifically measures the phenomena of the bipolar mixed state. This new scale includes clinically relevant symptoms of both mania and depression in a bivariate scale. The scale appears to capture key features of the mixed state and endorses the view that mixed states may be more than the sum of their parts. [source] Relationship between load/unload response ratio and damage variable and its applicationCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 12 2010Lang-Ping Zhang Abstract The physics-based parameter: load/unload response ratio (LURR) was proposed to measure the proximity of a strong earthquake, which achieved good results in earthquake prediction. As LURR can be used to describe the damage degree of the focal media qualitatively, there must be a relationship between LURR and damage variable (D) which describes damaged materials quantitatively in damage mechanics. Hence, based on damage mechanics and LURR theory, taking Weibull distribution as the probability distribution function, the relationship between LURR and D is set up and analyzed. This relationship directs LURR applied in damage analysis of materials quantitatively from being qualitative earlier, which not only provides the LURR method with a more solid basis in physics, but may also give a new approach to the damage evaluation of big scale structures and prediction of engineering catastrophic failure. Copyright © 2009 John Wiley & Sons, Ltd. [source] Observation of Mode like Coherent Structures in Curved Magnetic Fields of a Simple Magnetized TorusCONTRIBUTIONS TO PLASMA PHYSICS, Issue 4 2004F. Greiner Abstract The spatio-temporal dynamics of large-scale structures in curved magnetic field of simple magnetized torus (SMT) are presented. The experiments are performed in the SMT BLAAMANN and employ the techniques of conditional averaging (CA) and cross-correlation (CCF) of Langmuir probe data. By means of a detailed comparison of radio-frequency and thermionic discharges, it is shown that general features of the observed large-scale structures are independent of the discharge mechanism. Further, the observed large scale structures have a pronounced spatio-temporal periodicity, which suggests a description as mode-like. The conjectured relationship between the observed coherent structures and the inverse energy cascade is therefore questioned again. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Psychometric properties of the Pediatric Motor Activity Log used for children with cerebral palsyDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 3 2009MARGARET WALLEN MA BAPPSC(OT) The Pediatric Motor Activity Log (PMAL) is a parent-report measure of the use, by children with hemiplegic cerebral palsy (CP), of their affected upper limb in everyday activities. The aim of this study was to examine the psychometric properties of both scales of the PMAL (,How Often' and ,How Well' scales) using Rasch measurement modelling. Sixty-one parents of children with hemiplegic CP completed the PMAL and 31 completed it again 3 weeks later. The mean age of children was 4 years 6 months (SD 1y 9mo); 35 males, 26 females. Children were at Gross Motor Function Classification System (GMFCS) levels I (83%) and II (17%), and Manual Ability Classification System levels I (35%), II (52%), and III (14%). The original scales were found to have disordered rating scale structure. Further Rasch modelling with collapsed rating scale structures resulted in both scales conforming to the expectations of the Rasch model, yielding strong evidence for construct validity and reliability. One item from the How Often scale failed to conform to Rasch expectations and was deleted in subsequent analyses. Test,retest reliability of both scales was high (the intraclass correlation coefficient for the How Often scale was 0.94, and for the How Well scale 0.93). The revised scales possess good psychometric properties, specifically a logical item hierarchy, evidence of unidimensionality, adequate rating scale structure, and good test,retest reliability. We conclude that the revised PMAL has the capacity to yield valid and reliable scores except for children at the extremes of upper limb ability. [source] Prediction of sea surface temperature from the global historical climatology network dataENVIRONMETRICS, Issue 3 2004Samuel S. P. Shen Abstract This article describes a spatial prediction method that predicts the monthly sea surface temperature (SST) anomaly field from the land only data. The land data are from the Global Historical Climatology Network (GHCN). The prediction period is 1880,1999 and the prediction ocean domain extends from 60°S to 60°N with a spatial resolution 5°×5°. The prediction method is a regression over the basis of empirical orthogonal functions (EOFs). The EOFs are computed from the following data sets: (a) the Climate Prediction Center's optimally interpolated sea surface temperature (OI/SST) data (1982,1999); (b) the National Climatic Data Center's blended product of land-surface air temperature (1992,1999) produced from combining the Special Satellite Microwave Imager and GHCN; and (c) the National Centers for Environmental Prediction/National Center for Atmospheric Research Reanalysis data (1982,1999). The optimal prediction method minimizes the first- M -mode mean square error between the true and predicted anomalies over both land and ocean. In the optimization process, the data errors of the GHCN boxes are used, and their contribution to the prediction error is taken into account. The area-averaged root mean square error of prediction is calculated. Numerical experiments demonstrate that this EOF prediction method can accurately recover the global SST anomalies during some circulation patterns and add value to the SST bias correction in the early history of SST observations and the validation of general circulation models. Our results show that (i) the land only data can accurately predict the SST anomaly in the El Nino months when the temperature anomaly structure has very large correlation scales, and (ii) the predictions for La Nina, neutral, or transient months require more EOF modes because of the presence of the small scale structures in the anomaly field. Copyright © 2004 John Wiley & Sons, Ltd. [source] High-resolution seismic imaging in deep sea from a joint deep-towed/OBH reflection experiment: application to a Mass Transport Complex offshore NigeriaGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2010S. Ker SUMMARY We assess the feasibility of high-resolution seismic depth imaging in deep water based on a new geophysical approach involving the joint use of a deep-towed seismic device (SYSIF) and ocean bottom hydrophones (OBHs). Source signature measurement enables signature deconvolution to be used to improve the vertical resolution and signal-to-noise ratio. The source signature was also used to precisely determine direct traveltimes that were inverted to relocate source and receiver positions. The very high accuracy of the positioning that was obtained enabled depth imaging and a stack of the OBH data to be performed. The determination of the P -wave velocity distribution was realized by the adaptation of an iterative focusing approach to the specific acquisition geometry. This innovative experiment combined with advanced processing succeeded in reaching lateral and vertical resolution (2.5 and 1 m) in accordance with the objectives of imaging fine scale structures and correlation with in situ measurements. To illustrate the technological and processing advances of the approach, we present a first application performed during the ERIG3D cruise offshore Nigeria with the seismic data acquired over NG1, a buried Mass Transport Complex (MTC) interpreted as a debris flow by conventional data. Evidence for a slide nature of a part of the MTC was provided by the high resolution of the OBH depth images. Rigid behaviour may be inferred from movement of coherent material inside the MTC and thrust structures at the base of the MTC. Furthermore, a silt layer that was disrupted during emplacement but has maintained its stratigraphic position supports a short transport distance. [source] Rich Phase Behavior in a Supramolecular Conducting Material Derived from an OrganogelatorADVANCED FUNCTIONAL MATERIALS, Issue 6 2009Josep Puigmartí-Luis Abstract Organic conducting fiber-like materials hold great promise for the development of nanowires that can act as connections in miniature electronic devices, as an alternative to inorganic nanometer scale structures. This article presents a conducting organic tetrathiafulvalene-based supramolecular material which possesses a rich phase behavior with different packing of the molecules in the different forms, evidenced by electron spin resonance (ESR) spectroscopy. The distinct phases of conducting nanofibers can be easily fabricated through the temperature control of their preparation process from a xerogel by doping with iodine vapors. A total of four conducting phases have been identified conclusively using ESR spectroscopy as the key analytical tool. Three of the phases show a good long-term stability and areas in which the I,V curves have ohmic behavior when studied by current sensing (conducting) AFM. They offer promise for applications where electrical nanometer scale connections are required. [source] Molecular dynamics study on effects of surface structures in nanometer scale on energy transfer from fluid to surfaceHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 3 2005Masahiko Shibahara Abstract Energy transfer from fluid to surface was calculated numerically by using the classical molecular dynamics method in order to investigate the effects of surface structures from 0.1 nm to 10 nm on surface energy transfer. Surface structures on a constant surface area were composed of several hundred atoms having various potential energy parameters, in other words, thermal properties. The upper region in the calculation domain was controlled at a constant temperature and one of the solid atomic layers at the lower region in the calculation domain was controlled at another constant temperature to create a temperature gradient in the calculation system. Energy transfer to the surface was very dependent on surface nanometer scale structures in that affected the static structure and the dynamic behaviors of fluid molecules in the vicinity of the surface. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(3): 171,179, 2005; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/htj.20055 [source] Effects of High Water-Vapor Pressure on Oxidation of Silicon Carbide at 1200°CJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2003Peter F. Tortorelli The oxidation of SiC at 1200°C in a slowly flowing gas mixture of either air or air + 15 vol% H2O at 10 atm (1 MPa) was studied for extended times to examine the effects of elevated water-vapor pressure on oxidation rates and microstructural development. At a water-vapor pressure of 1.5 atm (150 kPa), distinct SiO2 scale structures were observed on the SiC; thick, porous, nonprotective cristobalite scales formed above a thin, nearly dense vitreous SiO2 layer, which remained constant in thickness with time as the crystalline SiO2 continued to grow. The pore morphology of the cristobalite layer differed depending on the type of SiC on which it was grown. The crystallization and growth rates of the cristobalite layer were significantly accelerated in the presence of the high water-vapor pressure and resulted in rapid rates of SiC surface recession that were on the order of what is observed when SiO2 volatility is rate controlling at high gas-flow velocities (30 m/s). The recession process can be described by a paralinear kinetic model controlled by the conversion of dense vitreous SiO2 to porous, nonprotective SiO2. [source] | |||||||||||||