85 research outputs found
A Survey of Out-of-School Activities of Third Grade Students with Above and Below Level Reading Achievement Scores
This study surveyed the out-of-school activities of third grade students with above and below level reading achievement scores. Twenty-one students scoring in the first through third and seventh through ninth stanines on the reading comprehension subtest of the Stanford Achievement Test participated in the study. Each child individually completed the out-of-school activities survey, designed and administered by the researcher.
Results of the survey indicated that significant differences do exist in the out-of-school activities of the subjects. The greatest number of differences existed between the above and below level third graders, and the above and below level third grade boys. A smaller number of differences were noted between boys and girls and the above and below level girls. Specific differences in activities are described in the study.
The relationship between out-of-school activities and reading achievement must be further investigated to determine the influence of out-of-school activities on reading achievement. Also recommended for further investigation are the effects of certain variables such as age and parental background on reading achievement and out-of-school activities
Furthering the understanding of silicate-substitution in α-tricalcium phosphate : an X-ray diffraction, X-ray fluorescence and solid-state nuclear magnetic resonance study
High-purity (SupT) and reagent-grade (ST), stoichiometric and silicate-containing α-tricalcium phosphate (α-TCP: ST0/SupT0 and Si-TCP x = 0.10: ST10/SupT10) were prepared by solid-state reaction based on the substitution mechanism Ca3(PO4)(2-x)(SiO4)x. Samples were determined to be phase pure by X-ray diffraction (XRD), and Rietveld analysis performed on the XRD data confirmed inclusion of Si in the α-TCP structure as determined by increases in unit cell parameters; particularly marked increases in the b-axis and ÎČ-angle were observed. X-ray fluorescence (XRF) confirmed the presence of expected levels of Si in Si-TCP compositions as well as significant levels of impurities (Mg, Al and Fe) present in all ST samples; SupT samples showed both expected levels of Si and a high degree of purity. Phosphorus (31P) magic-angle-spinning solid-state nuclear magnetic resonance (MAS NMR) measurements revealed that the high-purity reagents used in the synthesis of SupT0 can resolve the 12 expected peaks in the 31P spectrum of α-TCP compared to the low-purity ST0 that showed significant spectral line broadening; line broadening was also observed with the inclusion of Si which is indicative of induced structural disorder. Silicon (29Si) MAS NMR was also performed on both Si-TCP samples which revealed Q0 species of Si with additional Si Q1/Q2 species that may indicate a potential charge-balancing mechanism involving the inclusion of disilicate groups; additional Q4 Si species were also observed, but only for ST10. Heating and cooling rates were briefly investigated by 31P MAS NMR which showed no significant line broadening other than that associated with the emergence of ÎČ-TCP which was only realised with the reagent-grade sample ST0. This study provides an insight into the structural effects of Si-substitution in α-TCP and could provide a basis for understanding how substitution affects the physicochemical properties of the material
Analysis of the effects of atmospheric helium plasma treatment on the surface structure of jute fibres and resulting composite properties
Silicon-hydroxyapatite bioactive coatings (Si-HA) from diatomaceous earth and silica. Study of adhesion and proliferation of osteoblast-like cells
The aim of this study consisted on investigating
the influence of silicon substituted hydroxyapatite (SiâHA)
coatings over the human osteoblast-like cell line (SaOS-2)
behaviour. Diatomaceous earth and silica, together with
commercial hydroxyapatite were respectively the silicon
and HA sources used to produce the SiâHA coatings. HA
coatings with 0 wt% of silicon were used as control of the
experiment. Pulsed laser deposition (PLD) was the selected
technique to deposit the coatings. The SiâHA thin films
were characterized by Fourier Transformed Infrared
Spectroscopy (FTIR) demonstrating the efficient transfer of
Si to the HA structure. The in vitro cell culture was
established to assess the cell attachment, proliferation and
osteoblastic activity respectively by, Scanning Electron
Microscopy (SEM), DNA and alkaline phosphatase (ALP)
quantification. The SEM analysis demonstrated a similar
adhesion behaviour of the cells on the tested materials and
the maintenance of the typical osteoblastic morphology
along the time of culture. The SiâHA coatings did not
evidence any type of cytotoxic behaviour when compared
with HA coatings. Moreover, both the proliferation rate
and osteoblastic activity results showed a slightly better
performance on the SiâHA coatings from diatoms than on
the SiâHA from silica.This work was supported by the UE-Interreg IIIA (SP1.P151/03) Proteus project and Xunta de Galicia ( Projects: 2006/12 and PGIDITO5PXIC30301PN)
Mechanical and Water Intake Properties of Banana-Carbon Hybrid Fiber Reinforced Polymer Composites
Structure of Biocompatible Coatings Produced from Hydroxyapatite Nanoparticles by Detonation Spraying
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