New Insight into the Effect of the Formation Environment of Fh on Its Structure and Property

Hui Liu,   Xiuling Li,   Yan Wang,   Xin Yang,   Zhen Zhen,   Rufen Chen,   Denglu Hou and    Yu Wei  


Abstract

Ferrihydrite(Fh) is a naturally occurring nanoscale iron oxyhydroxide mineral. It is of great interest in soil science and environmental science due to its extremely high surface area and reactivity. In this work, Fh samples were prepared by three procedures (named Fh-1, Fh-2, and Fh-3). The formation of Fh-1 went through a pH change from acidic to neutral, and the formation of Fh-2 went through a pH change from alkaline to neutral, while Fh-3 was formed at a constant neutral pH. The three Fhs were characterized by high-resolution transmission electron microscopy (HRTEM), terahertz (THz) spectroscopy, nitrogen adsorption isotherms, and low-temperature magnetic techniques. All these techniques indicate that the microstructure and formation process of Fh are strongly coupled. More importantly, the differences of the three Fhs in microstructure are reflected not only in their bulk structure but also in their surface properties. The adsorption and degradation of azo dye Mordant Yellow 10 (MY10) on the three Fhs were investigated. On the one hand, comparing with Fh-1 and Fh-2, Fh-3 exhibits a high density of active site per area, which leads to a large adsorption capacity. On the other hand, a strong affinity between Fh-3 and MY10 results in a more irreversible adsorption and a low degradation rate. The results from current study shed new light on synergetic effects of porosity and the variations of local structure on photocatalysis by iron oxide particles.

Full Article: http://pubs.rsc.org/en/content/articlelanding/2014/ra/c4ra00696h#!divAbstract

Low-Bias THz Amplitude Modulator Based on Split-Ring Resonators and Graphene

Riccardo Degl'Innocenti , Davide Stephan Jessop , Yash Diptesh Shah , Juraj Sibik , J Axel Zeitler , Piran Ravichandran Kidambi , Stephan Hofmann , Harvey E Beere , and David Ritchie


Abstract

Split-ring resonators represent the ideal route to achieve optical control of the incident light at THz frequencies. These sub-wavelength metamaterial elements exhibit broad resonances that can be easily tuned lithographically. We realized a design based on the interplay between the resonances of metallic split-rings and the electronic properties of a monolayer graphene integrated in a single device. By varying the major carrier concentration of graphene, an active modulation of the optical intensity was achieved in the frequency range between 2.2 THz and 3.1 THz, achieving a maximum modulation depth of 18\%, with a bias as low as 0.5 V.

This study was performed using TeraView's TPI Imaga 2000 system. (TeraView, Cambridge, UK)

Full Article: http://pubs.acs.org/doi/abs/10.1021/nn406136c

TeraView Supplies Two Terahertz Systems to Leading Research Institutes in China

Press Release: 

The University of Electronic Science and Technology of China (电子科技大学), Chengdu, and The National Institute of Metrology (中国计量科学研究院) have both recently installed TeraView’s TPS Spectra 3000 spectrometers. The systems were selected due to their superior performance, ease of use and the Company’s track record with its existing customers in Asia.

The system at UESTC will be used by Prof Xiaodong Chen Visiting Professor from Queen Mary University London. Prof. Chen, who heads the department of Microwave Engineering in the Department of Electronic Engineering at QMUL, has a long standing history in the area of terahertz radiation research and has been a key contributor to the international terahertz community. The second TPS Spectra 3000 system at the National Institute of Metrology is supplied with TeraView's unique medical probe which provides three-dimensional information revealing structures beneath the surface with spatial resolution precision of 20 μm axial resolution of 40 μm.

“The growing interest in terahertz science and technology from China and recent developments in the area by prominent Chinese researchers have been remarkable” commented TeraView’s CEO, Don Arnone. “The success of our Asian business is evidence of our commitment to provide these customers with total solutions to their business needs, which is of up-most importance to users in this region. Being selected by such high-profile institutions strengthens TeraView’s position in the region as the leading supplier of turn-key terahertz systems. “

 

Terahertz Imaging for Nondestructive Evaluation of Packaged Power Electronic Devices

Nathan M. Burford1, Magda O. El-Shenawee2, Chad B. O’Neal3, Kraig J. Olejniczak4


Abstract

Terahertz (THz) time-domain imaging of power electronic devices is performed using the commercial TPSTM Spectra 3000 THz imaging and spectroscopy system. The dimensions of bond wires within power transistor packages are extracted and the time-of-flight tomography is used to illustrate depth profiling of features in the device package. The devices under test in this paper are plastic encapsulated. The encapsulation measures a few millimeters thick. The THz images obtained in the reflection mode demonstrate a potential tool for the non-destructive inspection of packaged power electronic devices.

This study was performed using TeraView's TPS Spectra 3000 system. (TeraView, Cambridge, UK)

Full Article: http://www.ijetae.com/files/Volume4Issue1/IJETAE_0114_69.pdf

Teraview at The American Coatings CONFERENCE 2014

TeraView are please to announce that they will be attending the American Coatings CONFERENCE on April the 7-9, 2014 in the Georgia World Congress Centre.

TeraView's Rob May and Ian Grundy will be in attendance, with Rob May presenting the following talk:

Title: Non-Contact, Substrate-Independent, Multi-Layer Paint Thickness Sensor

Session: 3.3

Date: 7th of April 2014

Time: 3:00-3:30 pm

Room: C208-210

For further information visit: http://www.american-coatings-show.com/en/conference