113,406 research outputs found
A Structural Comparison of Ordered and Non-Ordered Ion Doped Silicate Bioactive Glasses
One of the key benefits of sol-gel-derived glasses is the presence of a mesoporous structure
and the resulting increase in surface area. This enhancement in textural properties has a significant
e ect on the physicochemical properties of the materials. In this context the aim of this study was to
investigate how sol-gel synthesis parameters can influence the textural and structural properties of
mesoporous silicate glasses. We report the synthesis and characterization of metal ion doped sol-gel
derived glasses with di erent dopants in the presence or absence of a surfactant (Pluronic P123)
used as structure-directing templating agent. Characterization was done by several methods. Using
a structure directing agent led to larger surface areas and highly ordered mesoporous structures.
The chemical structure of the non-ordered glasses was modified to a larger extent than the one
of the ordered glasses due to increased incorporation of dopant ions into the glass network. The
results will help to further understand how the properties of sol-gel glasses can be controlled by
incorporation of metal dopants, in conjunction with control over the textural properties, and will be
important to optimize the properties of sol-gel glasses for specific applications, e.g., drug delivery,
bone regeneration, wound healing, and antibacterial materials.European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 643050, project “HyMedPoly
Textural properties of laksa noodle as affected by rice flour particle size
This study examined the physicochemical properties of rice flours with five different particle sizes (≤63, 80, 100, 125, and 140 μm) prepared by dry milling and their effects on textural properties of laksa noodles. Rice flour with the smallest particle size had the highest water absorption index, peak viscosity, hot paste viscosity, breakdown, final or cold paste viscosity and gel hardness, but the lowest gelatinization temperature. Reduction of rice flour particle size improved textural properties of laksa noodle. Laksa noodle produced from rice flour with the smallest particle size had the best textural properties
Modelling of wave climate and sediment transport patterns at a tideless embayed beach, Pirita Beach, Estonia
Nearshore sand transport patterns along the tideless, embayed Pirita beach, Tallinn, Estonia, have been investigated utilizing high-resolution modelling of wave processes combined with bathymetric surveys and sediment textural analyses of the nearshore sea floor. Textural analysis showed the mean grain size is about 0.12 mm. Fine sand (0.063–0.125 mm) accounts for about 77% of the sediments. Coarser-grained sand (0.28 mm) dominates along the waterline. Based upon the spatial distribution of the mean grain size and basic features of the local wave activity, properties of the Dean Equilibrium Beach Profile were determined.
Alongshore sediment transport was calculated based upon a long-term time series of wave properties along the beach, and the CERC formula applied to about 500 m long beach sectors. The time series of wave fields and the properties of the local wave climate were modelled using a triple nested WAM wave model with an extended spectral range for short waves. The model is forced by open sea wind data from Kalbådagrund for the years 1981–2002. Results indicate that typical closure depth at Pirita is 2.5 m. The width and mean slope of the equilibrium profile are 250 m and 1:100, respectively. Southward transport dominates in the northern sections of the beach whereas no prevailing transport direction exists in the southern sections. This pattern has several nontrivial implications for the planning of beach protection activities
Comparison of Short-grain Rice Cultivars Grown in Japan and the United States
Although short-grain rice accounts for less than 2% of U.S. rice production, the demand for short-grain rice is expected to increase because of the increasing popularity of sushi and sake. The objective of this study was to compare the physical, chemical and textural properties of short-grain rice cultivars grown in Japan and in the U.S. Seven short-grain rice cultivars from the 2016 crop year were collected, including five cultivars (Hatsushimo, Kinuhikari, Koshihikari, Nanatsuboshi, and Yumepirika) grown and purchased in grocery stores in Japan, one (RU9601099) grown in Arkansas, and one (CH-202) grown in California. The rice cultivars were characterized for kernel dimensions, color, chemical composition, amylopectin fine structure, and gelatinization, pasting and textural properties. RU9601099 had a smaller kernel width and a greater whiteness (L*) value than the other cultivars. Japanese cultivars were comparable in protein content, while RU9601099 had the greatest and CH-202 had the lowest protein content. RU9601099, CH-202 and Kinuhikari shared a similar value of average amylopectin chain length and gelatinization temperatures and enthalpy, which were significantly greater than the other cultivars. Kinuhikari and RU9601099 displayed greater peak and trough viscosities, whereas Hatsushimo and Nanatsuboshi had lower peak and breakdown viscosities. When cooked, the Japanese cultivars exhibited significantly greater hardness than the U.S. cultivars. Based on Ward’s cluster analysis considering all data, CH-202 shared similar properties with Kinuhikari, and RU9601099 was distinctively different from the other cultivars in most properties. The information obtained from this study will help future cultivar development and marketing of existing short-grain rice cultivars in the U.S
Breast-Lesion Characterization using Textural Features of Quantitative Ultrasound Parametric Maps
© 2017 The Author(s). This study evaluated, for the first time, the efficacy of quantitative ultrasound (QUS) spectral parametric maps in conjunction with texture-analysis techniques to differentiate non-invasively benign versus malignant breast lesions. Ultrasound B-mode images and radiofrequency data were acquired from 78 patients with suspicious breast lesions. QUS spectral-analysis techniques were performed on radiofrequency data to generate parametric maps of mid-band fit, spectral slope, spectral intercept, spacing among scatterers, average scatterer diameter, and average acoustic concentration. Texture-analysis techniques were applied to determine imaging biomarkers consisting of mean, contrast, correlation, energy and homogeneity features of parametric maps. These biomarkers were utilized to classify benign versus malignant lesions with leave-one-patient-out cross-validation. Results were compared to histopathology findings from biopsy specimens and radiology reports on MR images to evaluate the accuracy of technique. Among the biomarkers investigated, one mean-value parameter and 14 textural features demonstrated statistically significant differences (p < 0.05) between the two lesion types. A hybrid biomarker developed using a stepwise feature selection method could classify the legions with a sensitivity of 96%, a specificity of 84%, and an AUC of 0.97. Findings from this study pave the way towards adapting novel QUS-based frameworks for breast cancer screening and rapid diagnosis in clinic
Soil Particle Size Distribution Protocol
The purpose of this resource is to sure the distribution of different sizes of soil particles in each horizon of a soil profile. Using dry, sieved soil from a horizon, students mix the soil with water and a dispersing solution to completely separate the particles from each other. Students shake the mixture to fully suspend the soil in the water. The soil particles are then allowed to settle out of suspension, and the specific gravity and temperature of the suspension are measured using a hydrometer and thermometer. These measurements are taken after 2 minutes and 24 hours. Educational levels: Middle school, High school
Synthesis and textural properties of unsupported and supported rutile (TiO2) membranes
Two approaches were postulated for improving the stability of porous texture of titania membranes: (1) retarding the phase transformation and grain growth; (2) avoiding the phase transformation. Based on the second approach, rutile membranes were made directly from a rutile sol, prepared by the precipitation of titania on SnO2 nuclei. The rutile membranes were stable up to 800 °C, with a porosity of ca. 40%, whereas normal titania membranes (starting with anatase) show very little porosity above 600 °C. Alumina substitution retards grain growth and pore growth at 850 °C for unsupported as well as supported membranes. \u
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