scholarly journals Large-Scale Cu Nanowire Synthesis by PVP-Ethylene Glycol Route

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jhon L. Cuya Huaman ◽  
Iori Urushizaki ◽  
Balachandran Jeyadevan
Keyword(s):  
Ethylene Glycol ◽  
Large Scale ◽  
Average Length ◽  
Cost Benefit ◽  
Average Diameter ◽  
Atmospheric Conditions ◽  
Experimental Conditions ◽  
High Yields ◽  
Sequential Reduction ◽  
Multiply Twinned Particles

Cu nanowire (NW) is a promising cost-benefit conducting material that could be considered for the development of transparent conducting films (TCF). However, the development of Cu NW as an alternating material for Ag or Au is not only limited by its stability in atmospheric conditions in the nanometer range but also due to the nonavailability of a simple synthetic route to produce them in high yields and in large-scale. Here, a scheme to synthesize Cu NWs by reducing Cu nitrate in a Cl− ion-polyvinylpyrrolidine- (PVP-) ethylene glycol (EG) system is proposed. Cu NWs with average diameter around 60 nm and average length of about 40 μm was obtained under optimized experimental conditions. Furthermore, the formation of Cu NW was elucidated to be through the progression of the following sequential reduction steps: at first, Cu ions underwent partial reduction to form spherical Cu2O. Then, the spherical Cu2O particles were redissolved and reduced to metallic Cu0 atoms that subsequently formed the Cu seeds. Thereafter, Cu seeds underwent etching to form multiply-twinned particles (MTP). Finally, these Cu MTP grew unidirectionally to form metallic Cu NWs.

Electroless Deposition of Silver Nanowires Using Waste Ethylene Glycol for Highly Transparent Flexible Conducting Electrodes

2018 ◽  
Vol 775 ◽  
pp. 254-259
Author(s):  
Nathaniel de Guzman ◽  
Mary Donnabelle L. Balela
Keyword(s):  
Ethylene Glycol ◽  
Indium Tin Oxide ◽  
Silver Nanowires ◽  
Average Length ◽  
Average Diameter ◽  
Optical Transmittance ◽  
Transparent Conductive Electrode ◽  
Transparent Conducting ◽  
Better Than ◽  
Excellent Stability

High aspect ratio silver nanowires (AgNWs) with an average length of 40 μm and average diameter of 88 nm were successfully synthesized using waste ethylene glycol as solvent and reducing agent. Silver nanowires with an average length and diameter of 32 μm and 122 nm, were produced after the third cycle of being reused. A transparent conducting film with a sheet resistance of 69 Ω/sq and optical transmittance of 91% was fabricated by Meyer rod coating an ink formulation of AgNWs dispersed in hydroxyethyl celullose (HEC)/methanol/deionized water. The low resistance of the AgNW networks was maintained even after 1000 bending cycles due to HEC acting as binder for the nanowires. The AgNWHEC transparent conductive electrode performed better than bare AgNWs and indium tin oxide (ITO) on polyethylene terephthalate (PET) substrate after several bending cycles. The AgNW-HEC electrode also showed excellent stability against corrosion.

scholarly journals Direct Exfoliation of Natural SiO2-Containing Molybdenite in Isopropanol: A Cost Efficient Solution for Large-Scale Production of MoS2 Nanosheetes

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 843 ◽  
Author(s):  
Wenyan Zhao ◽  
Tao Jiang ◽  
Yujie Shan ◽  
Hongrui Ding ◽  
Junxian Shi ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Large Scale ◽  
Low Cost ◽  
Industrial Applications ◽  
Scale Production ◽  
Mos2 Nanosheets ◽  
Poly Ethylene Glycol ◽  
Experimental Conditions ◽  
Poly Ethylene ◽  
Layered Mos2

The cost-effective exfoliation of layered materials such as transition metal dichalcogenides into mono- or few- layers is of significant interest for various applications. This paper reports the preparation of few-layered MoS2 from natural SiO2-containing molybdenite by exfoliation in isopropanol (IPA) under mild ultrasonic conditions. One- to six-layer MoS2 nanosheets with dimensions in the range of 50-200 nm are obtained. By contrast, MoS2 quantum dots along with nanosheets are produced using N-methyl-pyrrolidone (NMP) and an aqueous solution of poly (ethylene glycol)-block-poly (propylene glycol)-block-poly (ethylene glycol) (P123) as exfoliation solutions. Compared with molybdenite, commercial bulk MoS2 cannot be exfoliated to nanosheets under the same experimental conditions. In the exfoliation process of the mineral, SiO2 associated in molybdenite plays the role of similar superfine ball milling, which significantly enhances the exfoliation efficiency. This work demonstrates that isopropanol can be used to exfoliate natural molybdenite under mild conditions to produce nanosheets, which facilitates the preparation of highly concentrated MoS2 dispersions or MoS2 in powder form due to the volatility of the solvent. Such exfoliated MoS2 nanosheets exhibit excellent photoconductivity under visible light. Hence, the direct mild exfoliation method of unrefined natural molybdenite provides a solution for low-cost and convenient production of few-layered MoS2 which is appealing for industrial applications.

Synthesis and Characterizing of High Aspect Ratio Silver Nanowires by Polyol Process

2018 ◽  
Vol 768 ◽  
pp. 75-84 ◽  
Author(s):  
Tian Rui Chen ◽  
Hai Feng Wang ◽  
Hui Yang ◽  
Xing Zhong Guo
Keyword(s):  
Ethylene Glycol ◽  
Electrode Materials ◽  
Selective Adsorption ◽  
Silver Nanowires ◽  
Average Length ◽  
Silver Ions ◽  
Average Diameter ◽  
Diameter Ratio ◽  
Conductive Materials ◽  
High Length

Silver nanowires with controllable and high length-diameter ratio were prepared by using the reductibility of ethylene glycol under high temperature and selective adsorption of PVP. AgNO3, ethylene glycol, PVP and CuCl2was used as the silver source, the reductant, the capping agent and the ion additives, respectively. The effects of centrifugal rate, silver ions' concentration, AgNO3adding rate on the morphology of silver nanowires were investigated by SEM, XRD, TEM and other technologies. The results show that the optimal centrifugal rate is 2000n/s, the better silver ions’ concentration is 6.55 mg/mL, and the best rate of adding AgNO3is 6 ml/min. The silver nanowires with an average diameter of 74.9 nm, the average length of 45.5μm and its length-diameter ratio of 607.5 are obtained. The silver nanowires with good morphology and high length-diameter ratio are adjustable, which is suitable for the preparation of OLED transparent film electrode materials, and other conductive materials.

scholarly journals Environmental Engineering Techniques to Restore Degraded Posidonia oceanica Meadows

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 661
Author(s):  
Luigi Piazzi ◽  
Stefano Acunto ◽  
Francesca Frau ◽  
Fabrizio Atzori ◽  
Maria Francesca Cinti ◽  
...  
Keyword(s):  
Large Scale ◽  
Natural Habitat ◽  
Cost Benefit ◽  
Cost Effective ◽  
Posidonia Oceanica ◽  
Environmental Engineering ◽  
Bottom Surface ◽  
Sessile Invertebrates ◽  
Set Up ◽  
Short Time

Seagrass planting techniques have shown to be an effective tool for restoring degraded meadows and ecosystem function. In the Mediterranean Sea, most restoration efforts have been addressed to the endemic seagrass Posidonia oceanica, but cost-benefit analyses have shown unpromising results. This study aimed at evaluating the effectiveness of environmental engineering techniques generally employed in terrestrial systems to restore the P. oceanica meadows: two different restoration efforts were considered, either exploring non-degradable mats or, for the first time, degradable mats. Both of them provided encouraging results, as the loss of transplanting plots was null or very low and the survival of cuttings stabilized to about 50%. Data collected are to be considered positive as the survived cuttings are enough to allow the future spread of the patches. The utilized techniques provided a cost-effective restoration tool likely affordable for large-scale projects, as the methods allowed to set up a wide bottom surface to restore in a relatively short time without any particular expensive device. Moreover, the mats, comparing with other anchoring methods, enhanced the colonization of other organisms such as macroalgae and sessile invertebrates, contributing to generate a natural habitat.

scholarly journals A simple and efficient automated microvolume radiosynthesis of [18F]Florbetaben

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Ksenia Lisova ◽  
Jia Wang ◽  
Philip H. Chao ◽  
R. Michael van Dam
Keyword(s):  
Large Scale ◽  
Solid Phase ◽  
Acetonitrile Solution ◽  
Synthesis Methods ◽  
Pet Tracers ◽  
Molar Activity ◽  
Alternative Approaches ◽  
High Yields ◽  
Sufficient Concentration

Abstract Background Current automated radiosynthesizers are generally optimized for producing large batches of PET tracers. Preclinical imaging studies, however, often require only a small portion of a regular batch, which cannot be economically produced on a conventional synthesizer. Alternative approaches are desired to produce small to moderate batches to reduce cost and the amount of reagents and radioisotope needed to produce PET tracers with high molar activity. In this work we describe the first reported microvolume method for production of [18F]Florbetaben for use in imaging of Alzheimer’s disease. Procedures The microscale synthesis of [18F]Florbetaben was adapted from conventional-scale synthesis methods. Aqueous [18F]fluoride was azeotropically dried with K2CO3/K222 (275/383 nmol) complex prior to radiofluorination of the Boc-protected precursor (80 nmol) in 10 μL DMSO at 130 °C for 5 min. The resulting intermediate was deprotected with HCl at 90 °C for 3 min and recovered from the chip in aqueous acetonitrile solution. The crude product was purified via analytical scale HPLC and the collected fraction reformulated via solid-phase extraction using a miniature C18 cartridge. Results Starting with 270 ± 100 MBq (n = 3) of [18F]Fluoride, the method affords formulated product with 49 ± 3% (decay-corrected) yield,> 98% radiochemical purity and a molar activity of 338 ± 55 GBq/μmol. The miniature C18 cartridge enables efficient elution with only 150 μL of ethanol which is diluted to a final volume of 1.0 mL, thus providing a sufficient concentration for in vivo imaging. The whole procedure can be completed in 55 min. Conclusions This work describes an efficient and reliable procedure to produce [18F]Florbetaben in quantities sufficient for large-scale preclinical applications. This method provides very high yields and molar activities compared to reported literature methods. This method can be applied to higher starting activities with special consideration given to automation and radiolysis prevention.

scholarly journals Performance of Strawberry Varieties Developed for Perennial Matted-Row Production in Annual Plasticulture in a Cold Climate Region

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1407
Author(s):  
Courtney A. Weber
Keyword(s):  
Large Scale ◽  
Fruit Size ◽  
Weather Conditions ◽  
Cold Climate ◽  
Annual Production ◽  
High Yield ◽  
Production Cycle ◽  
Late Season ◽  
Berry Weight ◽  
High Yields

Annual plasticulture production of strawberries promises superior weed control, fruit quality and yields. However, strawberry varieties adapted for perennial, matted-row production and local markets in cold climate regions have not been widely tested for adaptation to an annual production cycle. Productivity of seven short-day varieties developed for matted-row and/or annual production was examined in an annual plasticulture system in two consecutive trials in central NY (lat. 42.87° N, long. 76.99° W) harvested in 2013 and 2014. ‘Flavorfest’ demonstrated good performance in Trial 1 with high yield (390 g/plant) and large fruit size (13.9 g mean berry weight). ‘Jewel’ was shown to be well adapted to the annual plasticulture system with consistently high yields (330 and 390 g/plant) that equaled or surpassed other varieties and had moderate fruit size. ‘Chandler’ performed similarly to previous trials conducted in warmer regions with yield (340 g/plant) and fruit size (9.8 g mean berry weight) similar to ‘Jewel’. ‘Clancy’ yielded less but was consistent from year to year. The late season varieties Seneca and Ovation showed marked variability between years, possibly due to drastically different temperatures during flowering and fruit development in Trial 1 compared to Trial 2. High temperatures in Trial 1 likely caused higher early fruit yield, a compressed season and a precipitous decline in fruit size in the later season, thus reducing yield in the late season. Survival after a second dormant period was poor resulting in a small second harvest and reduced fruit size. Overall, the system demonstrated many of the expected benefits but may be more sensitive to weather conditions in the region. While many varieties developed for matted-row production may work well in an annual plasticulture system, not all varieties are equally adapted. Performance of each variety should be determined independently before large scale adoption by growers.

scholarly journals Compartment and hub definitions tune metabolic networks for metabolomic interpretations

GigaScience ◽  
2020 ◽  
Vol 9 (1) ◽  
Author(s):  
T Cameron Waller ◽  
Jordan A Berg ◽  
Alexander Lex ◽  
Brian E Chapman ◽  
Jared Rutter
Keyword(s):  
Large Scale ◽  
Metabolic Networks ◽  
Shortest Paths ◽  
Large Data ◽  
Differential Regulation ◽  
Large Data Sets ◽  
Data Sets ◽  
Human Metabolism ◽  
Experimental Conditions ◽  
Systemic Model

Abstract Background Metabolic networks represent all chemical reactions that occur between molecular metabolites in an organism’s cells. They offer biological context in which to integrate, analyze, and interpret omic measurements, but their large scale and extensive connectivity present unique challenges. While it is practical to simplify these networks by placing constraints on compartments and hubs, it is unclear how these simplifications alter the structure of metabolic networks and the interpretation of metabolomic experiments. Results We curated and adapted the latest systemic model of human metabolism and developed customizable tools to define metabolic networks with and without compartmentalization in subcellular organelles and with or without inclusion of prolific metabolite hubs. Compartmentalization made networks larger, less dense, and more modular, whereas hubs made networks larger, more dense, and less modular. When present, these hubs also dominated shortest paths in the network, yet their exclusion exposed the subtler prominence of other metabolites that are typically more relevant to metabolomic experiments. We applied the non-compartmental network without metabolite hubs in a retrospective, exploratory analysis of metabolomic measurements from 5 studies on human tissues. Network clusters identified individual reactions that might experience differential regulation between experimental conditions, several of which were not apparent in the original publications. Conclusions Exclusion of specific metabolite hubs exposes modularity in both compartmental and non-compartmental metabolic networks, improving detection of relevant clusters in omic measurements. Better computational detection of metabolic network clusters in large data sets has potential to identify differential regulation of individual genes, transcripts, and proteins.

scholarly journals Atmospheric Conditions Associated with Labrador Sea Deep Convection: New Insights from a Case Study of the 2006/07 and 2007/08 Winters

2016 ◽  
Vol 29 (14) ◽  
pp. 5281-5297 ◽  
Author(s):  
Who M. Kim ◽  
Stephen Yeager ◽  
Ping Chang ◽  
Gokhan Danabasoglu
Keyword(s):  
North America ◽  
North Atlantic ◽  
Large Scale ◽  
Initial Conditions ◽  
Deep Convection ◽  
La Niña ◽  
Labrador Sea ◽  
Atmospheric Conditions ◽  
Circulation Anomaly ◽  
La Nina

Abstract Deep convection in the Labrador Sea (LS) resumed in the winter of 2007/08 under a moderately positive North Atlantic Oscillation (NAO) state. This is in sharp contrast with the previous winter with weak convection, despite a similar positive NAO state. This disparity is explored here by analyzing reanalysis data and forced-ocean simulations. It is found that the difference in deep convection is primarily due to differences in large-scale atmospheric conditions that are not accounted for by the conventional NAO definition. Specifically, the 2007/08 winter was characterized by an atmospheric circulation anomaly centered in the western North Atlantic, rather than the eastern North Atlantic that the conventional NAO emphasizes. This anomalous circulation was also accompanied by anomalously cold conditions over northern North America. The controlling influence of these atmospheric conditions on LS deep convection in the 2008 winter is confirmed by sensitivity experiments where surface forcing and/or initial conditions are modified. An extended analysis for the 1949–2009 period shows that about half of the winters with strong heat losses in the LS are associated with such a west-centered circulation anomaly and cold conditions over northern North America. These are found to be accompanied by La Niña–like conditions in the tropical Pacific, suggesting that the atmospheric response to La Niña may have a strong influence on LS deep convection.

Growth Mechanism and Electrochemical Properties of Porous Hollow Tin Dioxide Nanospheres

NANO ◽  
2015 ◽  
Vol 10 (06) ◽  
pp. 1550087 ◽  
Author(s):  
Youwen Yang ◽  
Dongming Ma ◽  
Ting Cheng ◽  
Yuanhao Gao ◽  
Guanghai Li
Keyword(s):  
Growth Mechanism ◽  
Tin Dioxide ◽  
Ostwald Ripening ◽  
Lithium Ion ◽  
Average Diameter ◽  
Reversible Capacity ◽  
Cycling Performance ◽  
Experimental Conditions ◽  
Electrochemical Tests ◽  
Hydrolysis Method

Porous hollow SnO 2 nanospheres were prepared by means of enforced Sn 2+ hydrolysis method under hydrochloric acid medium. These hollow nanospheres with an average diameter of 220nm had a very thin shell thickness of about 40nm and were surrounded by elongated octahedral-like nanoparticles with the apex oriented outside. The experimental conditions, such as HCl content, reaction temperature and time directly dominated the morphology, structure and crystallinity of the obtained samples. A pre-oxidation-nucleation-growth mechanism and inside-out Ostwald-ripening method was proposed on the basis of the previous research and time-dependent experiments. Electrochemical tests showed that the porous hollow SnO 2 nanospheres exhibited improved cycling performance for anode materials of lithium-ion batteries, which retained a high reversible capacity of 540.0mAhg-1, and stable cyclic retention at 120th cycle.

scholarly journals Domain-Adversarial Training of Self-Attention-Based Networks for Land Cover Classification Using Multi-Temporal Sentinel-2 Satellite Imagery

2021 ◽  
Vol 13 (13) ◽  
pp. 2564
Author(s):  
Mauro Martini ◽  
Vittorio Mazzia ◽  
Aleem Khaliq ◽  
Marcello Chiaberge
Keyword(s):  
Land Cover ◽  
Large Scale ◽  
Domain Adaptation ◽  
Learning Approaches ◽  
Atmospheric Conditions ◽  
Practical Applications ◽  
Area Of Interest ◽  
Multi Temporal ◽  
Significant Performance ◽  
Adversarial Training

The increasing availability of large-scale remote sensing labeled data has prompted researchers to develop increasingly precise and accurate data-driven models for land cover and crop classification (LC&CC). Moreover, with the introduction of self-attention and introspection mechanisms, deep learning approaches have shown promising results in processing long temporal sequences in the multi-spectral domain with a contained computational request. Nevertheless, most practical applications cannot rely on labeled data, and in the field, surveys are a time-consuming solution that pose strict limitations to the number of collected samples. Moreover, atmospheric conditions and specific geographical region characteristics constitute a relevant domain gap that does not allow direct applicability of a trained model on the available dataset to the area of interest. In this paper, we investigate adversarial training of deep neural networks to bridge the domain discrepancy between distinct geographical zones. In particular, we perform a thorough analysis of domain adaptation applied to challenging multi-spectral, multi-temporal data, accurately highlighting the advantages of adapting state-of-the-art self-attention-based models for LC&CC to different target zones where labeled data are not available. Extensive experimentation demonstrated significant performance and generalization gain in applying domain-adversarial training to source and target regions with marked dissimilarities between the distribution of extracted features.

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