PMMA-titania floating macrospheres for the photocatalytic remediation of agro-pharmaceutical wastewater

2017 ◽  
Vol 75 (6) ◽  
pp. 1362-1369 ◽  
Author(s):  
Adam C. Hartley ◽  
Joseph B. Moss ◽  
Kyle J. Keesling ◽  
Nathanael J. Moore ◽  
Justin D. Glover ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Large Scale ◽  
Pond Water ◽  
Minimal Risk ◽  
Animal Feeding Operations ◽  
Confined Animal Feeding Operations ◽  
Solar Exposure ◽  
Large Size ◽  
Natural Pond ◽  
Lagoon Environment

Antibiotics such as tetracycline are used on a large scale in agriculture, and can become concentrated in wastewater lagoons that are used in conjunction with confined animal feeding operations. Solar-illuminated titanium dioxide can be used to photocatalytically degrade aqueous tetracycline, but its application in a lagoon environment requires that the photocatalyst be supported on a macroscopic support material to prevent loss of the nanoscale photocatalyst into the environment. In this work, titanium dioxide was deposited within a porous poly(methyl methacrylate) film on the surface of floating 7.0 cm diameter acrylic spheres. Six of these floating spheres removed over 96% of the tetracycline in 3.5 L of 60 mg/L tetracycline in natural pond water during 24 hours of solar illumination. The durability of these spheres under long-term solar exposure was also investigated along with the amount of photocatalyst lost from the sphere surface during use. These macroscale floating composite spheres provide a new method for removing tetracycline from wastewater lagoons with minimal risk of being displaced in the environment due to the large size of the spheres.

scholarly journals The Transformation from (111) to (100): A Routine to Large-Scale Epitaxial Diamond

2020 ◽  
Author(s):  
Yang Wang ◽  
Weihua Wang ◽  
Shilin Yang ◽  
Jiaqi Zhu
Keyword(s):  
Large Scale ◽  
Diamond Films ◽  
Diamond Growth ◽  
Nucleation Density ◽  
Diamond Synthesis ◽  
First Principle ◽  
High Quality ◽  
First Principle Calculations ◽  
Large Size ◽  
Experimental Researches

Diamond is a material with excellent performances which attracts the attention from researchers for decades. Pt (111), owing to its catalytic activity on diamond synthesis, is regarded to be a candidate for diamond hetero-epitaxity, which can enhance nucleation density. Molten surface at diamond growth temperature can also improve mobility and aggregation capability of primitive nuclei. Generally, (100)-oriented is welcomed for the achivement of high quality and large size diamond, since the formation of defects and twins are prevented. First-principle calculations and experimental researches were carried out for the study of transformation of orientation. The transformation from {111} to {100}-oriented diamond has been observed on Pt (111) substrate, which can be promoted by the increase of carbon source concentration and substrate temperature. The process is energetic favorable, which may provides a way towards large-scale (100) diamond films.

scholarly journals A Multi-Scale Modelling of Aggregation of TiO2 Nanoparticle Suspensions in Water

2021 ◽  
Author(s):  
Giulia Mancardi ◽  
Matteo Alberghini ◽  
Neus Aguilera-Porta ◽  
Monica Calatayud ◽  
Pietro Asinari ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Density Functional ◽  
Large Scale ◽  
Molecular Descriptors ◽  
Titanium Dioxide Nanoparticles ◽  
Accurate Determination ◽  
Multi Scale ◽  
Spherical Bead ◽  
Living Organisms ◽  
Dynamics Simulations

Titanium dioxide nanoparticles have risen concerns about their possible toxicity and the European Food Safety Authority recently banned the use of TiO2 nano-additive in food products. Following the intent of relating nanomaterials atomic structure with their toxicity without having to conduct large scale experiments on living organisms, we investigate the aggregation of titanium dioxide nanoparticles using a multi-scale technique: starting from ab initio Density Functional Theory to get an accurate determination of the energetics and electronic structure, we switch to classical Molecular Dynamics simulations to calculate the Potential of Mean Force for the connection of two identical nanoparticles in water; the fitting of the latter by a set of mathematical equations is the key for the upscale. Lastly, we perform Brownian Dynamics simulations where each nanoparticle is a spherical bead. This coarsening strategy allows studying the aggregation of a few thousand nanoparticles. Applying this novel procedure, we find three new molecular descriptors, namely, the aggregation free energy and two numerical parameters used to correct the observed deviation from the aggregation kinetic described by the Smoluchowski theory. Molecular descriptors can be fed into QSAR models to predict the toxicity of a material knowing its physicochemical properties, without having to conduct large scale experiments on living organisms.

scholarly journals Early Agenian rhinocerotids from Wischberg (Canton Bern, Switzerland) and clarification of the systematics of the genus Diaceratherium

2019 ◽  
Author(s):  
Claire Jame ◽  
Jérémy Tissier ◽  
Olivier Maridet ◽  
Damien Becker
Keyword(s):  
Large Scale ◽  
Phylogenetic Study ◽  
Fossil Remains ◽  
Large Size ◽  
Good State ◽  
The Future ◽  
Faunal Diversity ◽  
Faunal List ◽  
First Time

Background. Wischberg is a Swiss locality in Bern Canton which has yielded numerous vertebrates remains from the earliest Miocene (= MN1). It has a very rich faunal diversity, one of the richest in Switzerland for this age. Among all the mammals reported in the original faunal list 70 years ago, three rhinocerotid species were identified. The material consists of two fragmentary skulls, cranial fragments, several mandibles, teeth and postcranial bones, in a rather good state of preservation. Results. After reexamination of the material from this locality (curated in three different Swiss museums), and comparison with holotype specimens, we show that all rhinocerotid specimens from Wischberg can be referred to just two species. Most of the material can be attributed to the large size teleoceratine Diaceratherium lemanense, while only a few specimens, including a skull and mandible, belong to the much smaller sized Pleuroceros pleuroceros. We describe and illustrate for the first time most of these fossil remains. However, the systematics of the genus Diaceratherium is currently controversial, and we attempt to elucidate it based on our new observations, though a large-scale phylogenetic study should be done in the future to resolve it. The rhinocerotid association found in Wischberg is nonetheless typical of the MN1 biozone, which results from a faunal renewal occurring just before the end of the Oligocene.

scholarly journals Temperature-Dependent Raman Scattering of Large Size Hexagonal Bi2Se3 Single-Crystal Nanoplates

2018 ◽  
Vol 8 (10) ◽  
pp. 1794 ◽  
Author(s):  
Fang Zhou ◽  
Yujing Zhao ◽  
Weichang Zhou ◽  
Dongsheng Tang
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Temperature Coefficient ◽  
Thermoelectric Materials ◽  
Large Scale ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Large Size ◽  
Transmission Electron ◽  
High Figure

Bi 2 Se 3 has extensive application as thermoelectric materials. Here, large-scale Bi 2 Se 3 single-crystal hexagonal nanoplates with size 7.50–10.0 μ m were synthesized successfully by hydrothermal method. X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) were used to characterize the Bi 2 Se 3 nanoplates, which confirm the single-crystal quality and smooth surface morphology with large size. Micro-Raman spectra over a temperature range of 83–603 K were furthermore used to investigate the lattice dynamics of Bi 2 Se 3 nanoplates. Both 2A g 1 and 1E g 2 modes shift evidently with reduced temperature. The line shape demonstrates a significant broadening of full width at half maximum (FWHM) and red-shift of frequency with increased temperature. The temperature coefficient of A 1 g 1 , E g 2 , A 1 g 2 modes were determined to be −1.258 × 10 − 2 cm − 1 /K, −1.385 × 10 − 2 cm − 1 /K, −2.363 × 10 − 2 cm − 1 /K, respectively. Such low temperature coefficient may favor the obtaining of a high figure of merit (ZT) and indicate that Bi 2 Se 3 nanoplates were used as excellent candidates of thermoelectric materials.

scholarly journals Methods for Large-Scale Time-Triggered Network Scheduling

Electronics ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 738 ◽  
Author(s):  
Francisco Pozo ◽  
Guillermo Rodriguez-Navas ◽  
Hans Hansson
Keyword(s):  
Wireless Networks ◽  
Large Scale ◽  
Synthesis Method ◽  
Cyber Physical Systems ◽  
Network Scheduling ◽  
Synthesis Time ◽  
Physical Systems ◽  
Large Size ◽  
Np Complete ◽  
Communication Schedule

Future cyber–physical systems may extend over broad geographical areas, like cities or regions, thus, requiring the deployment of large real-time networks. A strategy to guarantee predictable communication over such networks is to synthesize an offline time-triggered communication schedule. However, this synthesis problem is computationally hard (NP-complete), and existing approaches do not scale satisfactorily to the required network sizes. This article presents a segmented offline synthesis method which substantially reduces this limitation, being able to generate time-triggered schedules for large hybrid (wired and wireless) networks. We also present a series of algorithms and optimizations that increase the performance and compactness of the obtained schedules while solving some of the problems inherent to segmented approaches. We evaluate our approach on a set of realistic large-size multi-hop networks, significantly larger than those considered in the existing literature. The results show that our segmentation reduces the synthesis time by up to two orders of magnitude.

scholarly journals Large-Scale Production of Large-Size Atomically Thin Semiconducting Molybdenum Dichalcogenide Sheets in Water and Its Application for Supercapacitor

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yu-Xiang Chen ◽  
Chien-Wei Wu ◽  
Ting-Yang Kuo ◽  
Yu-Lung Chang ◽  
Ming-Hsing Jen ◽  
...  
Keyword(s):  
Large Scale ◽  
Scale Production ◽  
Large Size ◽  
Large Scale Production
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