Search results for "rake"
showing 10 items of 866 documents
Developmental associations of accelerometer measured moderate-to-vigorous physical activity and sedentary time with cardiorespiratory fitness in scho…
2022
Objectives This study examined the developmental associations of accelerometer-based moderate-to-vigorous physical activity (MVPA) and sedentary time (ST) with cardiorespiratory fitness (CRF) in schoolchildren. Design A three-year follow-up study. Methods Participants were 446 (girls 57 %) Finnish children (M = 11.26 ± 0.32 years) from 17 randomly selected public schools in Finland. Accelerometer-based MVPA and ST were assessed using waist-worn activity monitors and CRF using the 20 m shuttle run test at four measurement points from 2017 to 2020. The developmental associations were tested using the Random Intercept Cross-Lagged Panel Model (RI-CLPM) reflecting MVPA, CRF, and ST overall leve…
Indoor air problems and the perceived social climate in schools: A multilevel structural equation analysis
2018
Indoor air problems in schools appear to influence learning outcomes and absence rates. However, previous research has not investigated whether indoor air problems influence the social climate of schools. Therefore, we studied whether indoor air problems observed in schools associate with students' perceptions of the teacher-student relationship and class spirit. The nationwide sample of Finnish schools (N = 194 schools/27153 students) was analyzed using multilevel structural equation modeling. Data on the schools' social climate collected from students were merged with independently collected data on observed indoor air problems from school principals. We found that the teacher-student rel…
Marketing or methodology? : Exposing the fallacies of PLS with simple demonstrations
2023
Purpose Over the past 20 years, partial least squares (PLS) has become a popular method in marketing research. At the same time, several methodological studies have demonstrated problems with the technique but have had little impact on its use in marketing research practice. This study aims to present some of these criticisms in a reader-friendly way for non-methodologists. Design/methodology/approach Key critiques of PLS are summarized and demonstrated using existing data sets in easily replicated ways. Recommendations are made for assessing whether PLS is a useful method for a given research problem. Findings PLS is fundamentally just a way of constructing scale scores for regression. PL…
Rejoinder: fractures in the edifice of PLS
2023
Purpose This study aims to provide a response to the commentary by Yuan on the paper “Marketing or Methodology” in this issue of EJM. Design/methodology/approach Conceptual argument and statistical discussion. Findings The authors find that some of Yuan’s arguments are incorrect, or unclear. Further, rather than contradicting the authors’ conclusions, the material provided by Yuan in his commentary actually provides additional reasons to avoid partial least squares (PLS) in marketing research. As such, Yuan’s commentary is best understood as additional evidence speaking against the use of PLS in real-world research. Research limitations/implications This rejoinder, coupled with Yuan’s comm…
Globally Optimized Equilibrium Shapes of Zirconia-Supported Rh and Pt Nanoclusters: Insights into Site Assembly and Reactivity
2019
Metal–support interfaces form an active site for many important catalytic reactions. The modeling of these interfacial sites calls for approximations to set up a structure model, which in turn may ...
Study of Coating/Work Material Interaction in Turning with Chip Forming Inserts
1997
This paper presents some interesting and novel results of an experimental study on the influence of the coating structure on the behaviour of the tribo-contact between the tool and the chip. The experiments involved TiC, TiC/TiN and TiC/Al2O3/TiN — coated flat-faced and grooved inserts in conjunction with a medium carbon steel and an austenitic stainless steel. Extensive experimental studies involving the cutting force and the tool-chip interface temperature were carried out. Two new parameters were introduced in order to compare both the mechanical and thermal loadings of the tool-chip contact for the two shapes of the rake face. Some optimal coating structures for high speed machining of …
First-principles insight into CO hindered agglomeration of Rh and Pt single atoms on m-ZrO2
2020
In this first-principles study we evaluate the thermodynamic and kinetic stability of Rh and Pt single-atoms (SAs) and subnano clusters on the monoclinic zirconia surface with and without a CO atmosphere. To address the kinetic stability and agglomeration of SAs to clusters and nanoparticles, a non-equilibrium nanothermodynamic approach is developed and parametrised using data computed with density functional theory. The bare subnano clusters are more stable than SA and become more so with increasing size, which means the agglomeration is always favoured. CO binds strongly to the single atoms and clusters, and our atomistic thermodynamics treatment indicates that some CO will be present eve…
Plasmon Excitations in Mixed Metallic Nanoarrays
2019
Features of the surface plasmon from macroscopic materials emerge in molecular systems, but differentiating collective excitations from single-particle excitations in molecular systems remains elusive. The rich interactions between single-particle electron-hole and collective electron excitations produce phenomena related to the chemical physics aspects within the atomic array. We study the plasmonic properties of atomic arrays of noble (Au, Ag, and Cu) and transition-metal (Pd, Pt) homonuclear chains using time-dependent density functional theory and their Kohn-Sham transition contributions. The response to the electromagnetic radiation is related to both the geometry-dependent confinement…
Structural stability of DNA origami nanostructures under application-specific conditions
2018
With the introduction of the DNA origami technique, it became possible to rapidly synthesize almost arbitrarily shaped molecular nanostructures at nearly stoichiometric yields. The technique furthermore provides absolute addressability in the sub-nm range, rendering DNA origami nanostructures highly attractive substrates for the controlled arrangement of functional species such as proteins, dyes, and nanoparticles. Consequently, DNAorigami nanostructures have found applications in numerous areas of fundamental and applied research, ranging from drug delivery to biosensing to plasmonics to inorganic materials synthesis. Since many of those applications rely on structurally intact, well-defin…
Preparation of graphene nanocomposites from aqueous silver nitrate using graphene oxide’s peroxidase-like and carbocatalytic properties
2020
AbstractThe present study evaluates the role of graphene oxide’s (GO’s) peroxidase-like and inherent/carbocatalytic properties in oxidising silver nitrate (AgNO3) to create graphene nanocomposites with silver nanoparticles (GO/Ag nanocomposite). Activation of peroxidase-like catalytic function of GO required hydrogen peroxide (H2O2) and ammonia (NH3) in pH 4.0 disodium hydrogen phosphate (Na2HPO4). Carbocatalytic abilities of GO were triggered in pH 4.0 deionised distilled water (ddH2O). Transmission electron microscope (TEM), scanning electron microscope (SEM), cyclic voltammetry (CV) and UV-Vis spectroscopy aided in qualitatively and quantitatively assessing GO/Ag nanocomposites. TEM and …