Polymerization Initiated by Particle Contact: A Quiescent State Trigger for Materials Synthesis

2016 ◽  
Vol 138 (38) ◽  
pp. 12336-12339 ◽  
Author(s):  
Kristin M. Hutchins ◽  
Nina M. Sekerak ◽  
Jeffrey S. Moore
Keyword(s):  
Quiescent State ◽  
Materials Synthesis ◽  
Particle Contact

Novel CO2-Thermic Oxidation Process with Mg-Based Intermetallic Compounds and Its Application to Energy Storage Materials

2018 ◽  
Author(s):  
Younghwan Cha ◽  
Jung-In Lee ◽  
Panpan Dong ◽  
Xiahui Zhang ◽  
Min-Kyu Song
Keyword(s):  
Intermetallic Compounds ◽  
Oxidation Process ◽  
Value Added ◽  
Energy Storage Materials ◽  
Reaction Products ◽  
Materials Synthesis ◽  
Energy Materials ◽  
A Value ◽  
Carbon Coated ◽  
Novel Strategy

A novel strategy for the oxidation of Mg-based intermetallic compounds using CO<sub>2</sub> as an oxidizing agent was realized via simple thermal treatment, called ‘CO2-thermic Oxidation Process (CO-OP)’. Furthermore, as a value-added application, electrochemical properties of one of the reaction products (carbon-coated macroporous silicon) was evaluated. Considering the facile tunability of the chemical/physical properties of Mg-based intermetallics, we believe that this route can provide a simple and versatile platform for functional energy materials synthesis as well as CO<sub>2</sub> chemical utilization in an environment-friendly and sustainable way.

Mitotic Activity Dynamics in Recalcitrant Seeds Acer sachharinum during Maturation and Germination

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 479c-479
Author(s):  
L. Kozeko ◽  
V. Troyan ◽  
L. Musatenko
Keyword(s):  
Cell Division ◽  
Mitotic Activity ◽  
Quiescent State ◽  
Activity Levels ◽  
Recalcitrant Seeds ◽  
Mature Embryos ◽  
Before And After ◽  
Orthodox Seeds ◽  
Mature Seeds ◽  
Activity Dynamics

In orthodox seeds the cell division within the embryo meristems arrests during maturation at embryo moisture content (MC) 65% to 47%, and the maturation completion and transition of seeds to quiescent state occurs at MC about 10%. The arrest of cycling happens asynchronously in different meristematic tissues during desiccation: first in shoot and then in root. The aim of this work was to define a mitotic activity dynamics in recalcitrant seeds with the high MC at maturation end and the absence of quiescent state characteristic of it. The object was seeds of Acer saccharinum, using widely for planting of greenery in Kiev city. The mitotic activity was determined in 0.5 mm of the embryo root pole (RP) and 0.5 mm of the shoot pole with embryo leaves (SP). The A. sachharinum seeds completed them maturation at MC 53% (FW basis). During maturation the mitotic index (MI) in RP decreased from 3.2% in immature seeds (at embryos MC 80%) to 0 in mature seeds and in SP–from 5.4% to 3.3%, respectively. Cell division in SP arrested by dehydration of mature embryos to MC 46% by PEG 6000 (30%). The seeds lost viability by desiccation to MC 34%. The mature seeds were able to germinate immediately after abscission. During seed germination the cell division reactived in RP and increased in SP already before root protrusion. In plantlets 10–15 mm long the MI increased to 8% in RP and 12% in SP. Thus, the strategy of immediate germination of recalcitrant A. sachharinum seeds includes a preservation of cell division in SP of mature embryos, in contrast with orthodox seeds, and high mitotic activity levels in meristems of germinating embryos before and after root protrusion.

Polymeric textile-based electromagnetic interference shielding materials, their synthesis, mechanism and applications – A review

2021 ◽  
pp. 152808372110370
Author(s):  
Faiza Safdar ◽  
Munir Ashraf ◽  
Amjed Javid ◽  
Kashif Iqbal
Keyword(s):  
Electromagnetic Interference ◽  
Hybrid Composites ◽  
Electronic Devices ◽  
High Tech ◽  
Emi Shielding ◽  
Materials Synthesis ◽  
Synthesis Mechanism ◽  
High Frequencies ◽  
Textile Materials ◽  
Shielding Composites

The rapid proliferation of electronic devices and their operation at high frequencies has raised the contamination of artificial electromagnetic radiations in the atmosphere to an unprecedented level that is responsible for catastrophe for ecology and electronic devices. Therefore, the lightweight and flexible electromagnetic interference (EMI) shielding materials are of vital importance for controlling the pollution generated by such high-frequency EM radiations for protecting ecology and human health as well as the other nearby devices. In this regard, polymeric textile-based shielding composites have been proved to be the best due to their unique properties such as lightweight, excellent flexibility, low density, ease of processability and ease of handling. Moreover, such composites cover range of applications from everyday use to high-tech applications. Various polymeric textiles such as fibers, yarn, woven, nonwoven, knitted, as well as their hybrid composites have been extensively manipulated physically and/or chemically to act as shielding against such harmful radiations. This review encompasses from basic concept of EMI shielding for beginner to the latest research in polymeric-based textile materials synthesis for experts, covering detailed mechanisms with schematic illustration. The review also covers the gap of materials synthesis and their application on polymeric textiles which could be used for EMI shielding applications. Furthermore, recent research regarding rendering EMI shielding properties at various stages of polymeric textile development is provided for readers with critical analysis. Lastly, the applications along with environmental compliance have also been presented for better understanding.

scholarly journals Dynamic changes of podocytes caused by fibroblast growth factor 2 in culture

2021 ◽  
Author(s):  
Eishin Yaoita ◽  
Masaaki Nameta ◽  
Yutaka Yoshida ◽  
Hidehiko Fujinaka
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Fibroblast Growth Factor 2 ◽  
Quiescent State ◽  
Fibroblast Growth ◽  
Gene Expressions ◽  
Dynamic Changes ◽  
Ki 67

AbstractFibroblast growth factor 2 (FGF2) augments podocyte injury, which induces glomerulosclerosis, although the mechanisms remain obscure. In this study, we investigated the effects of FGF2 on cultured podocytes with interdigitating cell processes in rats. After 48 h incubation with FGF2 dynamic changes in the shape of primary processes and cell bodies of podocytes resulted in the loss of interdigitation, which was clearly shown by time-lapse photography. FGF2 reduced the gene expressions of constituents of the slit diaphragm, inflections of intercellular junctions positive for nephrin, and the width of the intercellular space. Immunostaining for the proliferation marker Ki-67 was rarely seen and weakly stained in the control without FGF2, whereas intensely stained cells were frequently found in the presence of FGF2. Binucleation and cell division were also observed, although no significant increase in cell number was shown. An in vitro scratch assay revealed that FGF2 enhanced migration of podocytes. These findings show that FGF2 makes podocytes to transition from the quiescent state into the cell cycle and change their morphology due to enhanced motility, and that the culture system in this study is useful for analyzing the pathological changes of podocytes in vivo.

scholarly journals Controlled Fabrication of Quality ZnO NWs/CNTs and ZnO NWs/Gr Heterostructures via Direct Two-Step CVD Method

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1836
Author(s):  
Nicholas Schaper ◽  
Dheyaa Alameri ◽  
Yoosuk Kim ◽  
Brian Thomas ◽  
Keith McCormack ◽  
...  
Keyword(s):  
Direct Synthesis ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Materials Synthesis ◽  
Oxide Nanowires ◽  
Cvd Method ◽  
Thermal Actuators ◽  
Potential Applications ◽  
Walled Carbon Nanotubes ◽  
Scalable Production

A novel and advanced approach of growing zinc oxide nanowires (ZnO NWs) directly on single-walled carbon nanotubes (SWCNTs) and graphene (Gr) surfaces has been demonstrated through the successful formation of 1D–1D and 1D–2D heterostructure interfaces. The direct two-step chemical vapor deposition (CVD) method was utilized to ensure high-quality materials’ synthesis and scalable production of different architectures. Iron-based universal compound molecular ink was used as a catalyst in both processes (a) to form a monolayer of horizontally defined networks of SWCNTs interfaced with vertically oriented ZnO NWs and (b) to grow densely packed ZnO NWs directly on a graphene surface. We show here that our universal compound molecular ink is efficient and selective in the direct synthesis of ZnO NWs/CNTs and ZnO NWs/Gr heterostructures. Heterostructures were also selectively patterned through different fabrication techniques and grown in predefined locations, demonstrating an ability to control materials’ placement and morphology. Several characterization tools were employed to interrogate the prepared heterostructures. ZnO NWs were shown to grow uniformly over the network of SWCNTs, and much denser packed vertically oriented ZnO NWs were produced on graphene thin films. Such heterostructures can be used widely in many potential applications, such as photocatalysts, supercapacitors, solar cells, piezoelectric or thermal actuators, as well as chemical or biological sensors.

scholarly journals Autonomous reinforcement learning agent for chemical vapor deposition synthesis of quantum materials

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Pankaj Rajak ◽  
Aravind Krishnamoorthy ◽  
Ankit Mishra ◽  
Rajiv Kalia ◽  
Aiichiro Nakano ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Reinforcement Learning ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Time Behavior ◽  
Materials Synthesis ◽  
Design Synthesis ◽  
Learning Agent ◽  
Threshold Temperatures ◽  
Quantum Materials

AbstractPredictive materials synthesis is the primary bottleneck in realizing functional and quantum materials. Strategies for synthesis of promising materials are currently identified by time-consuming trial and error and there are no known predictive schemes to design synthesis parameters for materials. We use offline reinforcement learning (RL) to predict optimal synthesis schedules, i.e., a time-sequence of reaction conditions like temperatures and concentrations, for the synthesis of semiconducting monolayer MoS2 using chemical vapor deposition. The RL agent, trained on 10,000 computational synthesis simulations, learned threshold temperatures and chemical potentials for onset of chemical reactions and predicted previously unknown synthesis schedules that produce well-sulfidized crystalline, phase-pure MoS2. The model can be extended to multi-task objectives such as predicting profiles for synthesis of complex structures including multi-phase heterostructures and can predict long-time behavior of reacting systems, far beyond the domain of molecular dynamics simulations, making these predictions directly relevant to experimental synthesis.

scholarly journals Mixed Oxide Layered Double Hydroxide Materials: Synthesis, Characterization and Efficient Application for Mn2+ Removal from Synthetic Wastewater

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4089
Author(s):  
Cristina Modrogan ◽  
Simona Cǎprǎrescu ◽  
Annette Madelene Dǎncilǎ ◽  
Oanamari Daniela Orbuleț ◽  
Eugeniu Vasile ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Layered Double Hydroxides ◽  
Synthetic Wastewater ◽  
Precipitation Method ◽  
Metallic Ions ◽  
Materials Synthesis ◽  
Experimental Conditions ◽  
Edx Analysis ◽  
Co Precipitation ◽  
Double Hydroxides

Magnesium–aluminum (Mg-Al) and magnesium–aluminum–nickel (Mg-Al-Ni) layered double hydroxides (LDHs) were synthesized by the co-precipitation method. The adsorption process of Mn2+ from synthetic wastewater was investigated. Formation of the layered double hydroxides and adsorption of Mn2+ on both Mg-Al and Mg-Ni-Al LDHs were observed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometry (EDX) analysis. XRD patterns for prepared LDHs presented sharp and symmetrical peaks. SEM studies revealed that Mg-Al LDH and Mg-Al-Ni LDH exhibit a non-porous structure. EDX analysis showed that the prepared LDHs present uniformly spread elements. The adsorption equilibrium on these LDHs was investigated at different experimental conditions such as: Shaking time, initial Mn2+ concentration, and temperatures (10 and 20 °C). The parameters were controlled and optimized to remove the Mn2+ from synthetic wastewater. Adsorption isotherms of Mn2+ were fitted by Langmuir and Freundlich models. The obtained results indicated that the isotherm data fitted better into the Freundlich model than the Langmuir model. Adsorption capacity of Mn2+ gradually increased with temperature. The Langmuir constant (KL) value of Mg-Al LDH (0.9529 ± 0.007 L/mg) was higher than Mg-Al-Ni LDH (0.1819 ± 0.004 L/mg), at 20 °C. The final adsorption capacity was higher for Mg-Al LDH (91.85 ± 0.087%) in comparison with Mg-Al-Ni LDH (35.97 ± 0.093%), at 20 °C. It was found that the adsorption kinetics is best described by the pseudo-second-order model. The results indicated that LDHs can be considered as a potential material for adsorption of other metallic ions from wastewater.

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