Size Controlled Synthesis of Magnetite Nanoparticles Using Microwave Irradiation Method

2013 ◽  
Vol 24 ◽  
pp. 184-193 ◽  
Author(s):  
K. Prem Ananth ◽  
Sujin P. Jose ◽  
K.S. Venkatesh ◽  
R. Ilangovan
Keyword(s):  
Microwave Irradiation ◽  
Magnetite Nanoparticles ◽  
Magnetic Nanoparticle ◽  
Nanoparticle Synthesis ◽  
Cubic Phase ◽  
Microwave Irradiation Method ◽  
Experimental Conditions ◽  
Wide Range ◽  
Powder Samples ◽  
Vibration Sample Magnetometer

The experimental conditions play an important role in particle size and in their properties in multifunctional magnetic nanoparticle synthesis. In the present study, magnetite nanoparticles of various sizes were synthesized by microwave irradiation method. The synthesized powder samples were characterized using XRD and SEM which substantiated the formation of magnetic nanoparticle in cubic phase. The particle sizes obtained were 40 nm, 31 nm and 27 nm from TEM micrographs. The FTIR studies confirmed the characteristic band of Fe-O within the range of 574 - 580 cm-1. The magnetic properties of the samples were measured by vibration sample magnetometer that confirmed ferrimagnetic behavior of magnetite nanoparticles at room temperature. From the present study, it is observed that the microwave irradiation method is a convenient method to produce a wide range of magnetite nanoparticles of desired size for a variety of novel biomedical applications.

Triply-periodic nanostructures in surfactant, block copolymer, and biomembrane systems, and simulation of TEMs

1993 ◽  
Vol 51 ◽  
pp. 884-885
Author(s):  
David M. Anderson ◽  
Tomas Landh
Keyword(s):  
Liquid Crystalline ◽  
Diblock Copolymers ◽  
Cubic Phase ◽  
List Type ◽  
Interpenetrating Networks ◽  
Triply Periodic ◽  
Wide Range ◽  
Bicontinuous Cubic ◽  
Phase Liquid ◽  
Dividing Surface

First discovered in surfactant-water liquid crystalline systems, so-called ‘bicontinuous cubic phases’ have the property that hydropnilic and lipophilic microdomains form interpenetrating networks conforming to cubic lattices on the scale of nanometers. Later these same structures were found in star diblock copolymers, where the simultaneous continuity of elastomeric and glassy domains gives rise to unique physical properties. Today it is well-established that the symmetry and topology of such a morphology are accurately described by one of several triply-periodic minimal surfaces, and that the interface between hydrophilic and hydrophobic, or immiscible polymer, domains is described by a triply-periodic surface of constant, nonzero mean curvature. One example of such a dividing surface is shown in figure 5.The study of these structures has become of increasing importance in the past five years for two reasons:1)Bicontinuous cubic phase liquid crystals are now being polymerized to create microporous materials with monodispersed pores and readily functionalizable porewalls; figure 3 shows a TEM from a polymerized surfactant / methylmethacrylate / water cubic phase; and2)Compelling evidence has been found that these same morphologies describe biomembrane systems in a wide range of cells.

Strongly Coupled Redox-Linked Conformational Switching at the Active Site of the Non-Heme Iron-Dependent Dioxygenase, TauD

2019 ◽  
Author(s):  
Christopher John ◽  
Greg M. Swain ◽  
Robert P. Hausinger ◽  
Denis A. Proshlyakov
Keyword(s):  
Active Site ◽  
Structural Model ◽  
Heme Iron ◽  
Chemical Transformations ◽  
Experimental Conditions ◽  
Strongly Coupled ◽  
Non Heme Iron ◽  
Reversible Redox ◽  
Wide Range ◽  
Complex Structural

2-Oxoglutarate (2OG)-dependent dioxygenases catalyze C-H activation while performing a wide range of chemical transformations. In contrast to their heme analogues, non-heme iron centers afford greater structural flexibility with important implications for their diverse catalytic mechanisms. We characterize an <i>in situ</i> structural model of the putative transient ferric intermediate of 2OG:taurine dioxygenase (TauD) by using a combination of spectroelectrochemical and semi-empirical computational methods, demonstrating that the Fe (III/II) transition involves a substantial, fully reversible, redox-linked conformational change at the active site. This rearrangement alters the apparent redox potential of the active site between -127 mV for reduction of the ferric state and 171 mV for oxidation of the ferrous state of the 2OG-Fe-TauD complex. Structural perturbations exhibit limited sensitivity to mediator concentrations and potential pulse duration. Similar changes were observed in the Fe-TauD and taurine-2OG-Fe-TauD complexes, thus attributing the reorganization to the protein moiety rather than the cosubstrates. Redox difference infrared spectra indicate a reorganization of the protein backbone in addition to the involvement of carboxylate and histidine ligands. Quantitative modeling of the transient redox response using two alternative reaction schemes across a variety of experimental conditions strongly supports the proposal for intrinsic protein reorganization as the origin of the experimental observations.

scholarly journals Low-Energy Electron Damage to Condensed-Phase DNA and Its Constituents

2021 ◽  
Vol 22 (15) ◽  
pp. 7879
Author(s):  
Yingxia Gao ◽  
Yi Zheng ◽  
Léon Sanche
Keyword(s):  
Condensed Phase ◽  
Genetic Material ◽  
High Energy ◽  
Dna Lesions ◽  
Low Energy ◽  
Experimental Investigations ◽  
Experimental Conditions ◽  
Strand Breaks ◽  
Sequence Of Events ◽  
Wide Range

The complex physical and chemical reactions between the large number of low-energy (0–30 eV) electrons (LEEs) released by high energy radiation interacting with genetic material can lead to the formation of various DNA lesions such as crosslinks, single strand breaks, base modifications, and cleavage, as well as double strand breaks and other cluster damages. When crosslinks and cluster damages cannot be repaired by the cell, they can cause genetic loss of information, mutations, apoptosis, and promote genomic instability. Through the efforts of many research groups in the past two decades, the study of the interaction between LEEs and DNA under different experimental conditions has unveiled some of the main mechanisms responsible for these damages. In the present review, we focus on experimental investigations in the condensed phase that range from fundamental DNA constituents to oligonucleotides, synthetic duplex DNA, and bacterial (i.e., plasmid) DNA. These targets were irradiated either with LEEs from a monoenergetic-electron or photoelectron source, as sub-monolayer, monolayer, or multilayer films and within clusters or water solutions. Each type of experiment is briefly described, and the observed DNA damages are reported, along with the proposed mechanisms. Defining the role of LEEs within the sequence of events leading to radiobiological lesions contributes to our understanding of the action of radiation on living organisms, over a wide range of initial radiation energies. Applications of the interaction of LEEs with DNA to radiotherapy are briefly summarized.

scholarly journals Review of the Upright Balance Assessment Based on the Force Plate

2021 ◽  
Vol 18 (5) ◽  
pp. 2696
Author(s):  
Baoliang Chen ◽  
Peng Liu ◽  
Feiyun Xiao ◽  
Zhengshi Liu ◽  
Yong Wang
Keyword(s):  
Postural Balance ◽  
Force Plate ◽  
Assessment Method ◽  
Balance Assessment ◽  
Experimental Conditions ◽  
Methodological Research ◽  
Assessment Tests ◽  
Wide Range ◽  
Foot Posture ◽  
Plate System

Quantitative assessment is crucial for the evaluation of human postural balance. The force plate system is the key quantitative balance assessment method. The purpose of this study is to review the important concepts in balance assessment and analyze the experimental conditions, parameter variables, and application scope based on force plate technology. As there is a wide range of balance assessment tests and a variety of commercial force plate systems to choose from, there is room for further improvement of the test details and evaluation variables of the balance assessment. The recommendations presented in this article are the foundation and key part of the postural balance assessment; these recommendations focus on the type of force plate, the subject’s foot posture, and the choice of assessment variables, which further enriches the content of posturography. In order to promote a more reasonable balance assessment method based on force plates, further methodological research and a stronger consensus are still needed.

scholarly journals Towards Reduced CNNs for De-Noising Phase Images Corrupted with Speckle Noise

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 255
Author(s):  
Marie Tahon ◽  
Silvio Montresor ◽  
Pascal Picart
Keyword(s):  
Phase Error ◽  
Speckle Noise ◽  
Experimental Conditions ◽  
Benchmark Data ◽  
Wide Range ◽  
Phase Images ◽  
Different Depths ◽  
Phase Data ◽  
Do So

Digital holography is a very efficient technique for 3D imaging and the characterization of changes at the surfaces of objects. However, during the process of holographic interferometry, the reconstructed phase images suffer from speckle noise. In this paper, de-noising is addressed with phase images corrupted with speckle noise. To do so, DnCNN residual networks with different depths were built and trained with various holographic noisy phase data. The possibility of using a network pre-trained on natural images with Gaussian noise is also investigated. All models are evaluated in terms of phase error with HOLODEEP benchmark data and with three unseen images corresponding to different experimental conditions. The best results are obtained using a network with only four convolutional blocks and trained with a wide range of noisy phase patterns.

Cellulose-g-PAM Derived from Kenaf for Ethyl Orange Removal

2016 ◽  
Vol 818 ◽  
pp. 246-249 ◽  
Author(s):  
Siti Fatimah Mohamed Razak ◽  
Norzita Ngadi ◽  
Nurul Jannah Arsad
Keyword(s):  
Waste Water ◽  
Microwave Irradiation ◽  
Ftir Spectroscopy ◽  
Microwave Irradiation Method ◽  
Spectroscopy Analysis

A novel hybrid flocculant of acrylamide and cellulose was synthesized by using microwave irradiation method. Cellulose was extracted from kenaf by using TAPPI method. 57.4% of percentage grafting and efficiency has been obtained from the grafting process. There are additional peaks that appeared in FTIR spectroscopy analysis that show PAM was grafted into cellulose backbone. The flocculation behavior was studied by using ethyl orange wastewater. The result shows that hybrid flocculant (cellulose-g-PAM) has potential to be used as flocculant in treating dyes waste water.

Microwave synthesis of high rate nanostructured LiMnBO3 with excellent cyclic behavior for lithium ion batteries

RSC Advances ◽  
2014 ◽  
Vol 4 (60) ◽  
pp. 31851-31854 ◽  
Author(s):  
Kaliyappan Karthikeyan ◽  
Yun Sung Lee
Keyword(s):  
Microwave Irradiation ◽  
Lithium Ion Batteries ◽  
Microwave Synthesis ◽  
Lithium Ion ◽  
High Rate ◽  
Cyclic Behavior ◽  
Microwave Irradiation Method

LiMnBO3 nanobeads (LMB-NB) prepared using a urea assisted microwave irradiation method delivered 67 mA h g−1 capacity at 0.6 C rate between 1.25 and 4.8 V, showing 88% cyclability after 100 cycles.

Sign in / Sign up

Export Citation Format

Share Document