Wednesday, 21 February 2018

Pulsed terahertz imaging of breast cancer in freshly excised murine tumors

Bowman, Tyler, Tanny Chavez, Kamrul Khan, Jingxian Wu, Avishek Chakraborty, Narasimhan Rajaram, Keith Bailey, and Magda El-Shenawee. "Pulsed terahertz imaging of breast cancer in freshly excised murine tumors." Journal of Biomedical Optics 23, no. 2 (2018): 026004.



Abstract

This paper investigates terahertz (THz) imaging and classification of freshly excised murine xenograft breast cancer tumors. These tumors are grown via injection of E0771 breast adenocarcinoma cells into the flank of mice maintained on high-fat diet. Within 1 h of excision, the tumor and adjacent tissues are imaged using a pulsed THz system in the reflection mode. The THz images are classified using a statistical Bayesian mixture model with unsupervised and supervised approaches. Correlation with digitized pathology images is conducted using classification images assigned by a modal class decision rule. The corresponding receiver operating characteristic curves are obtained based on the classification results. A total of 13 tumor samples obtained from 9 tumors are investigated. The results show good correlation of THz images with pathology results in all samples of cancer and fat tissues. For tumor samples of cancer, fat, and muscle tissues, THz images show reasonable correlation with pathology where the primary challenge lies in the overlapping dielectric properties of cancer and muscle tissues. The use of a supervised regression approach shows improvement in the classification images although not consistently in all tissue regions. Advancing THz imaging of breast tumors from mice and the development of accurate statistical models will ultimately progress the technique for the assessment of human breast tumor margins


"This work makes use of the TPS Spectra 3000 THz pulsed imaging and spectroscopy system (TeraView, Ltd., United Kingdom) at the University of Arkansas."


For more information about TeraView see https://www.azom.com/article.aspx?ArticleID=14796




For full paper see https://www.spiedigitallibrary.org/journals/Journal-of-Biomedical-Optics/volume-23/issue-2/026004/Pulsed-terahertz-imaging-of-breast-cancer-in-freshly-excised-murine/10.1117/1.JBO.23.2.026004.short?SSO=1

Monday, 19 February 2018

The 9th International Symposium on Ultrafast Phenomena and Terahertz Waves (ISUPTW 2018)

On behalf of the Program Committee, we are pleased to announce that The 9th International Symposium on Ultrafast Phenomena and Terahertz Waves (ISUPTW 2018) will be held in Changsha, China from April 23 to 26, 2018. ISUPTW 2018 is organized by National University of Denfense Technology (NUDT) and the Optical Society of America (OSA). More information will be released in the website.

ISUPTW, an international symposium, is devoted to strengthening the collaboration among worldwide researchers and promoting the development in Ultrafast and Terahertz science and technology. The biennial symposium, initiated in 2002, has been held in Beijing, Shanghai, Nanjing, Tianjin, Xi'an, and Wuhan. It brings together scientists, technologists, and students from more than 10 countries and typically hosts 150-300 participants.

This symposium provides an excellent opportunity to share and exchange ideas. We look forward to welcoming our friends and colleagues from all around the world. The paper submission system is open now. We warmly invite you and your colleagues as well as students to submit the latest work. The contributed papers will be archived on EI Compendex by OSA. We believe you will not only enjoy the exchange and discussions on ultrafast phenomena and terahertz wave, but will also have a memorable experience in Changsha, China.

It is our great pleasure to invite you to attend this symposium.Your contributions are crucial to the success of these exciting events.

We look forward to seeing you in Changsha, China.

Topics may include, but are not limited to:
Symposium I: The development of ultrafast phenomena and ultrashort pulse laser
1. Ultrafast science and technology;
2. Ultrafast phenomena in micro and nano-structures;
3. High-speed diagnosis, high-speed imaging, and high-speed data processing etc;
4. High-field physics and attosecond science;
5. Ultra high intensity laser and its application;
Symposium II: Terahertz science and technology 1. Extreme terahertz science and technology;
2. Terahertz science and technology in micro and nano-structures;
3. Terahertz spectroscopy and the interaction between terahertz radiation and materials.
4. Terahertz wave transmission and communication;
5. Terahertz imaging and its application;
6. The applications of terahertz wave in industry, defense, and astronomy.

for more information see http://ampg.nudt.edu.cn/isuptw/index.html

8th International Workshop on Terahertz Technology and Applications


March 20th/21st 2018 in Kaiserslautern (Germany)

7th Workshop on Terahertz Technology and Applications (Bild: VDI e.V.)
8th International Workshop on Terahertz Technology and Applications

Nowadays terahertz technology has proven to be a valuable tool for applications in diagnostics, measurement and testing. The industrial use of this technology, however, puts a lot of challenging questions. The 8th “International Workshop on Terahertz Technology and Applications” especially fosters the exchange of knowledge and experience between academics and industry in this exciting and rapidly developing field.

The workshop will address primarily the topics:
  1. Non-destructive testing
  2. Technology for homeland security
  3. Communications
  4. Health and social aspects of terahertz technology
  5. New THz system Technologies


The workshop is focused on the subjects below:
  • sources and detectors,
  • imaging and
  • millimeter-wave testing.

It also addresses:
  • spectroscopy,
  • communication,
  • coatings and
  • regulative aspects of Terahertz radiation.

The international workshop is jointly organised by VDI/VDE Society Measurement and Automatic Control and Fraunhofer ITWM. 

for more information see https://www.vdi.de/index.php?id=47465

Friday, 16 February 2018

Call for Papers – 43rd International Conference on Infrared, Millimeter and Terahertz Waves

We are very happy to announce that the 43rd International Conference on Infrared, 
Millimeter and Terahertz Waves (IRMMW-THz 2018) is now open for accepting submissions
of one-page abstracts. The deadline is March 31st, 2018.

IRMMW-THz 2018 will be held in Nagoya, Japan during September 9-14, 2018.
The conference venue is Nagoya Congress Center. Nagoya city is the 4th largest city in Japan,
and the venue is located within 4 km (or 10 min by train) from the downtown of the city.
The access from the Chubu Centrair International Airport in Nagoya is very convenient,
and it takes about 30-40 minutes by the express trains. For more detail,
please visit our website http://irmmw-thz2018.org/index.html.

Topics at the conference include, but are not strictly limited to:
1.    Astronomy, Planetary and Environmental Science
2.    Applications in Biology and Medicine
3.    Applications in Industry, Security and Inspection
4.    Spectroscopy and Material Properties
5.    Spectroscopy of Gases, Liquids, and Solids
6.    Sources, Detectors, and Receivers
7.    Imaging and Remote Sensing
8.    Modeling and Analysis Techniques
9.    Metamaterial Structures and Applications
10.    Devices, Components, and Systems
11.    High-Field THz Wave Generation and Nonlinear THz Physics
12.    MM and sub-MM wave systems
13.    Laser Driven THz Sources
14.    Quantum Cascade Lasers
15.    Gyro-Oscillators and Amplifiers
16.    Free Electron Lasers and Synchrotron Radiation
17.    Ultrafast Measurements
18.    Metrology
19.    MMW and THz Wave Radar and Communications
20.    2D Materials for MMW, THz, IR Applications

We are very much looking forward to welcoming you to Nagoya for a week
with 300+ exciting talks and plentiful poster sessions reporting on the latest advances in this field,
as well as technical exhibits with the newest THz technology and networking with your old and
new colleagues in the largest forum for IR, millimeter and terahertz wave science and technology !

Best wishes

Dr. Toshitaka Idehara
Dr. Masahiko Tani
Chairs of IRMMW-THz 2018 (Nagoya, Japan)
http://irmmw-thz2018.org

Tuesday, 13 February 2018

Presentation at IFPAC 2018

Dissolution Modeling of a Controlled Release Osmotic Tablet using Terahertz Pulsed Imaging (TPI): A Chemometric Approach 


Zach Dance1, Brian Regler1, Donna Carroll1, Busolo Wabuyele1, Jerry Klinzing1, Jim DiNunzio1, Gary Chia1, Lee Dowden1, Gerard Bredael1, David Harris1, Zhihao Lin1, Phil Taday2
[1Merck & Co., Inc., 2TeraView Ltd.]

see https://www.xcdsystem.com/IFPAC/program/sEg2Mf6/index.cfm

Abstract: 

Push-pull osmotic tablets are currently being developed for controlled release of compound A in order to provide once daily dosing. The release rate of compound A from the osmotic tablet has been found to be largely controlled by the coating thickness. Terahertz pulsed imaging (TPI) uses short pulses of terahertz radiation (2-120 cm-1) that penetrate typical pharmaceutical components. The time delay of reflections of these pulses from materials of different refractive indexes in the sample allows for the measurement of thickness of various materials. Using TPI, the coating thickness of compound A osmotic tablets can be measured in a rapid, non-destructive manner across an entire tablet. The coating thickness data obtained using TPI was found to be in line with other analysis techniques such as XRCT. Combining the dissolution release rate data from products designed to provide different drug release rates through modification of coating weight, a chemometric model was developed to predict release rate as a function of coating thickness.


Monday, 12 February 2018

The Impact of Interference from the Side Lanes on mmWave/THz Band V2V Communication Systems with Directional Antennas

Petrov, Vitaly, Joonas Kokkoniemi, Dmitri Moltchanov, Janne Lehtomaki, Markku Juntti, and Yevgeni Koucheryavy. "The Impact of Interference from the Side Lanes on mmWave/THz Band V2V Communication Systems with Directional Antennas." IEEE Transactions on Vehicular Technology(2018).


Abstract:

Communications systems operating in the millimeter and terahertz band have been recently suggested to enable high data-rate vehicle-to-vehicle communications in future networks. However, massive deployment of such systems may lead to significant interference, affecting the performance of information transmission. While the multipath interference caused by the signal reflections from the road has been extensively discussed in literature, the interference caused by the vehicles on the side lanes has been insufficiently studied so far. In this paper, using a combination of measurement, simulation, and analytical methods we comprehensively characterize the interference from the side lanes in two typical deployments including highway and urban road environments for millimeter and low terahertz bands. Both the multipath interference and direct interference from the transmitting vehicles on the side lanes are taken into account. As a result of the presented study, we reveal that: i) the interference from the side lanes can be well approximated using two-dimensional stochastic models without any notable loss of accuracy; and ii) even when highly directional antennas are used there are special spatial configurations, where the interference may greatly affect the communication systems performance. We lately apply the developed models to estimate the signal-to-interference ratio and link capacity of mmWave/THz band V2V communications with directional antennas.



To measure the signal losses, we used the TeraView TeraPulse 4000 [46] platform, based on THz time domain spectroscopy (THz-TDS) … 


For full paper see http://ieeexplore.ieee.org/abstract/document/8272491/
for more information about TeraView is https://www.azom.com/article.aspx?ArticleID=14796

Friday, 2 February 2018

Terahertz Bandpass Filter Based on Frequency Selective Surface

Li, Jiu-Sheng, Yang Li, and Le Zhang. "Terahertz Bandpass Filter Based on Frequency Selective Surface." IEEE Photonics Technology Letters 30, no. 3 (2018): 238-241.

Abstract:
We designed a terahertz bandpass filter based on double-layer frequency selective surface. Details of the proposed terahertz wave filter design and of the related parametric analysis are presented and discussed. The proposed terahertz filter was fabricated by laser technology. The transmission spectrum was characterized by terahertz time-domain spectroscopy. The results show that the center frequency of the terahertz filter is about 1 THz with 3-dB bandwidth of 400 GHz.
for full paper see http://ieeexplore.ieee.org/document/8194866/
for more information about TeraView is https://www.azom.com/article.aspx?ArticleID=14796

Plasmonic Nanodisk Thin-Film Terahertz Photoconductive Antenna

Burford, Nathan M., Michael J. Evans, and Magda O. El-Shenawee. "Plasmonic Nanodisk Thin-Film Terahertz Photoconductive Antenna." IEEE Transactions on Terahertz Science and Technology (2017).

Abstract:

This paper presents the design, fabrication, and measurement of a plasmonic thin-film terahertz photoconductive antenna. Conventional terahertz photoconductive antennas suffer from poor optical-to-terahertz conversion efficiency, often on the order of 10−4. This is due to the low quantum efficiency of the device. The goal of this work is to demonstrate enhanced terahertz emission from a plasmonic thin-film device architecture. The combination of plasmonic nanodisks, a 120-nm low-temperature-grown gallium arsenide thin-film, and a bottom-located bowtie antenna has demonstrated the feasibility of producing such devices. Fabrication attempts and failure analysis is discussed in this work. Experimental characterization measuring the peak-to-peak electric field values of the terahertz pulses emitted from the device prototypes showed approximately five times improvement in plasmonic thin-film devices compared to conventional devices. The plasmonic thin-film devices had a measureable terahertz bandwidth of ∼5 THz. This indicates that the plasmonic thin-film architecture has a potential for producing high optical-to-terahertz conversion efficiencies across a wide frequency range.
for full paper see http://ieeexplore.ieee.org/abstract/document/8239849/
for more information about TeraView is https://www.azom.com/article.aspx?ArticleID=14796

Resolving the rapid water absorption of porous functionalised calcium carbonate powder compacts by terahertz pulsed imaging

Markl, Daniel, Parry Wang, Cathy Ridgway, Anssi-Pekka Karttunen, Prince Bawuah, Jarkko Ketolainen, Patrick Gane, Kai-Erik Peiponen, and J. Axel Zeitler. "Resolving the Rapid Water Absorption of Porous Functionalised Calcium Carbonate Powder Compacts by Terahertz Pulsed Imaging." Chemical Engineering Research and Design (2018).

Abstract

Cost effectiveness, ease of use and patient compliance make pharmaceutical tablets the most popular and widespread form to administer a drug to a patient. Tablets typically consist of an active pharmaceutical ingredient and a selection from various excipients. A novel highly porous excipient, functionalised calcium carbonate (FCC), was designed to facilitate rapid liquid uptake leading to disintegration times of FCC based tablets in the matter of seconds. Five sets of FCC tablets with a target porosity of 45–65% in 5% steps were prepared and characterised using terahertz pulsed imaging (TPI). The high acquisition rate (15 Hz) of TPI enabled the analysis of the rapid liquid imbibition of water into these powder compacts. The penetration depth determined from the TPI measurements as a function of time was analysed by the power law and modelled for both the inertial (initial phase) and Lucas-Washburn (LW, longer time Laplace-​Poiseuillian) regimes. The analysis of the hydraulic radius estimated by fitting the liquid imbibition data to the LW equation demonstrates the impact of the porosity as well as the tortuosity of the pore channels on the liquid uptake performance. The tortuosity was related to the porosity by a geometrical model, which shows that the powder compact is constructed by aggregated particles with low permeability and its principal axis perpendicular to the compaction direction. The consideration of the tortuosity yielded a very high correlation (R2 = 0.96) between the porosity and the hydraulic pore radius. The terahertz data also resolved fluctuations (0.9–1.3 Hz) of the liquid movement which become more pronounced and higher in frequency with increasing porosity, which is attributed to the constrictivity of pore channels. This study highlights the strong impact of a tablet's microstructure on its liquid penetration kinetics and thus on its disintegration behaviour.

for full paper see https://www.sciencedirect.com/science/article/pii/S0263876218300017
for more information about TeraView is https://www.azom.com/article.aspx?ArticleID=14796

Damage assessment in composite materials using full wavefield analysis

WANDOWSKI, Tomasz, Pawel H. MALINOWSKI, and Wieslaw M. OSTACHOWICZ. "Damage assessment in composite materials using full wavefield analysis." see http://www.ndt.net/article/aero2017/papers/NDT2017-014_Damage_assessment_in_composite_materials_using_full_wavefield_analysis.pdf

Abstract 

In this paper damage assessment method is presented. This method is based on phenomenon of guided elastic waves propagation. Guided waves are generated by piezoelectric transducer and registered by Scanning Laser Doppler Vibrometer (SLDV). Signal processing is based on the analysis of full wave-field measurements. In this approach guided wave signals are gathered from dense mesh of measurement points spanned over investigated area of investigated structure. This approach allows to create animations representing the guided wave propagation which are suitable for analysis of interaction of guided waves with different discontinuities located in composite material. In the research attention is especially focused on analysis of phenomenon of guided wave mode conversion. This phenomenon occurs due to the interaction of guided wave with discontinuities in the structure. Guided wave mode conversion phenomenon has potential for damage detection. Method is validated for the fibre reinforced composite materials. In the research such discontinuities like delamination simulated by teflon insert with different shapes and location as well as true delamination created by impact are investigated. In the research auxiliary nondestructive testing (NDT) method is utilized. The aim of this method is to indicate the depth of discontinuity, and to prove that delamination was created. Auxiliary method is based on terahertz spectroscopy (THz). This method is based on analysis of propagation of electromagnetic waves in the terahertz band. THz spectroscopy method can be utilized for damage assessment in the materials that do not conduct electric current. 

for more information about TeraView is https://www.azom.com/article.aspx?ArticleID=14796

Thermally induced tunability of a terahertz metamaterial by using a specially designed nematic liquid crystal mixture

Kowerdziej, Rafał, Marek Olifierczuk, and Janusz Parka. "Thermally induced tunability of a terahertz metamaterial by using a specially designed nematic liquid crystal mixture." Optics Express 26, no. 3 (2018): 2443-2452.

Abstract
Article CoverThe search for new low loss nematic liquid crystal mixtures with enhanced birefringence and low temperature of nematic-to-isotropic phase transition plays a pivotal role in a development of new applications in the emerging field of thermally tunable metamaterials. Here we maximize thermally induced tunability of a terahertz metamaterial by using a specially designed nematic liquid crystal mixture. It is shown that the resonant response of a metamaterial device can be effectively tuned both in terms of its magnitude and wavelength with the spectral tunability approaching the theoretical limit of 8 GHz. Electromagnetic simulations confirm our tests and match the experimental observations well. The suggested approach opens new routes for next-generation soft-matter-based filtering and sensing components and devices.


"of the metamaterial when loaded with a nematic liquid crystal mixture during the heating process, THz-TDS (TeraView TPS 3000 …" 
for more information about TeraView is https://www.azom.com/article.aspx?ArticleID=14796