Wednesday, October 29, 2014

Abstract-Optical Properties of Tetrahydrofuran Clathrate Hydrates with Polyvinylpyrrolidone (THF + H2O + PVP) Revealed by Terahertz (THz) Time-Domain Spectroscopy


Hyery Kang Dong-Yeun Koh Yun-Ho Ahn Seonghoon Jung §Jaehun Park §Jaehyoung Lee*, and Huen Lee *
 Department of Chemical and Biomolecular Engineering (BK21+ program), KAIST, Daejeon 305-701, Republic of Korea
 Graduate School of EEWS, KAIST, Daejeon 305-701, Republic of Korea
§ Pohang Accelerator Laboratory, POSTECH, Pohang 790-784, Republic of Korea
 Petroleum & Marine Research Division, Korea Institute of Geoscience & Mineral Resources, Gwahang-no 92, 30, Yuseong-gu, Daejeon 305-350, Republic of Korea
J. Chem. Eng. Data, Article ASAP
DOI: 10.1021/je5005092
Publication Date (Web): October 29, 2014
Copyright © 2014 American Chemical Society
*(H.L.) E-mail: hlee@kaist.ac.kr., *(J.L.) E-mail: ljh1155@kigam.re.kr

Abstract Image
Terahertz time-domain spectroscopy (THz-TDS) was used to observe the tetrahydrofuran (THF) clathrate hydrate system with dosage of polyvinylpyrrolidone (PVP) with three different average molecular weights (10 000 g/mol, 40 000 g/mol, and 360 000 g/mol). Distinct footprints of phase transition in the THz region (0.4 THz to 2.2 THz) were analyzed and absorption coefficients and complex refractive indices are obtained and compared in the temperature range of 253 to 288 K. Along with the optical properties, ring breathing and stretching modes for different molecular weights of PVP in THF hydrate are analyzed by Raman spectroscopy.

Abstract-Molecular Recognition and Interaction between Uracil and Urea in Solid-State Studied by Terahertz Time-Domain Spectroscopy



J. Phys. Chem. A, Just Accepted Manuscript
DOI: 10.1021/jp506045q
Publication Date (Web): October 28, 2014
Copyright © 2014 American Chemical Society

Using terahertz time-domain spectroscopy characterization, we observe that urea is able to recognize and interact with uracil efficiently even in solid phase without involving water or solvents. A cocrystal configuration linked by a pair of hydrogen bonds between uracil and urea was formed. Terahertz absorption spectrum of the cocrystal shows a distinct new absorption at 0.8 THz (26.7 cm-1) which originates from the intermolecular hydrogen bonding. Both mechanical milling and heating can accelerate the reaction efficiently. Density functional theory was adopted to simulate the vibrational modes of the cocrystal and the results agree well with the experimental observation. Multi-techniques, including powder X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy were performed to investigate the reaction process and presented supportive evidences. This work enables in-depth understanding of recognition and interaction of urea with nucleobases, and comprehending the denaturation related to RNA. We also demonstrate that terahertz spectroscopy is an effective and alternative tool for online measurement and quality control in pharmaceutical and chemical industry.

Tuesday, October 28, 2014

Lockheed, Pentagon reach agreement on new F-35 contract, - Britian and Israel confirm new purchases


(My NOTE: I included this news as Advanced Photonix (API) performs the paint and other  Exterior inspections on the F-35, using Terahertz. (Thanks to John daly!)
http://advancedphotonix.com/thzsolutions/markets/qcndt/aircraft-non-destructive-testing/)

BY STEVE KASKOVICH
http://www.star-telegram.com/2014/10/27/6235225/lockheed-pentagon-reach-agreement.html


Lockheed Martin and the Pentagon announced a deal Monday on a production contract for the next batch of F-35 fighter jets, which is projected to lower the price per plane by 3.6 percent.
The contract, expected to be finalized in the next several weeks, would cover 43 F-35 aircraft including 29 for the U.S. military, the first two for Israel, the first four for Japan, four for the United Kingdom and two each for Norway and Italy.
Deliveries from what is known as “Low-Rate Initial Production lot 8” would begin in 2016. The Pentagon said cost details will be released later, but sources told Reuters last week that it is worth about $4 billion.
In a statement, Lt. Gen. Chris Bogdan, the top Pentagon official over the F-35, said the agreement represents the program’s “ongoing maturation.”
“Once production of [the new contract’s] aircraft is completed, more than 200 F-35s will be in operation by eight nations,” he said.
The F-35, which is being built in west Fort Worth, has been dogged by technical problems and cost overruns for years but has made progress on both fronts in the past year.
In the summer, however, the U.S. military’s fleet was grounded after an engine caught fire at Eglin Air Force Base, Fla., forcing the Pentagon to cancel the F-35’s scheduled appearance at the high-profile Farnborough International Airshow in England. Officials have identified the cause of the fire, and flight testing has resumed with more frequent engine inspections.
In July in Fort Worth, the Pentagon’s top acquisition chief said the engine fire was unlikely to delay a planned increase in production, which is needed to reduce the average cost of the plane, currently around $100 million. Lockheed and the Pentagon are aiming to boost production of the F-35, now at about 36 a year, to more than 120 a year by the end of the decade.
More than 6,000 people work directly on the F-35 program in west Fort Worth, and increased production could add upward of 1,000 jobs over several years, Lockheed officials have said.
On Monday, a top Lockheed F-35 executive said the new production contract is indicative of efforts to make the plane more affordable.
“Affordability is a key performance parameter in today’s challenging acquisition environment.” Lockheed F-35 program manager Lorraine Martin said in a statement. “Working together with our suppliers, we are making steady progress in reducing F-35 costs.”
RELATED:

Israel to buy 25 more F-35 Lockheed stealth fighters: sources

(Reuters) - Israel plans to buy a second batch of Lockheed Martin's F-35 stealth fighter jets, bringing its total number on order to about 44, Israeli defense and U.S. sources said on Tuesday.
Israel bought 19 F-35s for $2.75 billion in 2010, a deal that included options for up to 75 planes. Israeli Defence Minister Moshe Yaalon, visiting the United States last week, placed a preliminary order for about 25 more F-35s, the defense sources said without elaborating on cost. see more: http://www.reuters.com/article/2014/10/28/us-israel-defence-lockheed-martin-idUSKBN0IH14T20141028

Britain to confirm first F-35 orders 'within weeks'

London (AFP) - Britain on Tuesday announced an agreement in principle with US manufacturer Lockheed Martin for an order for the first of 14 F-35B combat jets, with a formal contract expected "within weeks".
The four Lightning II stealth combat aircraft will operate from both of the Royal Navy's new aircraft carriers and Royal Air Force land bases, with another 10 due to be ordered over the next five years. see more:




Read more here: http://www.star-telegram.com/2014/10/27/6235225/lockheed-pentagon-reach-agreement.html#storylink=cpy

Photo Release -- Northrop Grumman Sets World Record with One-Terahertz Circuit, Achieves One Trillion Cycles per Second



Center, Philip Robertson, representative, Guinness World Records, presents the world record certificate for the fastest integrated circuit amplifier to, from left, Dr. Dale Burton, sector vice president and chief technology officer, Northrop Grumman Aerospace Systems; Dr. Arati Prabhakar, director, DARPA; Dr. Dev Palmer, DARPA Terahertz Electronics program manager; and Dr. William Deal, Northrop Grumman Terahertz Electronics program manager. The amplifier uses 10 transistor stages to reach an operating speed of one trillion cycles per second and could lead to revolutionary technologies such as high-resolution security imaging systems, improved collision-avoidance radar, higher-capacity communications networks and advanced spectrometers. - 

http://globenewswire.com/news-release/2014/10/28/677323/10104912/en/Photo-Release-Northrop-Grumman-Sets-World-Record-with-One-Terahertz-Circuit-Achieves-One-Trillion-Cycles-per-Second.html

MANHATTAN BEACH, Calif. – Oct. 28, 2014 – Northrop Grumman Corporation (NYSE:NOC), a leader in advanced microelectronics, has developed the world's fastest integrated circuit amplifier, which has been recognized by Guinness World Records. The amplifier uses 10 transistor stages to reach an operating speed of one terahertz (1012 Hz), or one trillion cycles per second—surpassing the company's own performance record of 850 billion cycles per second set in 2012. 

DARPA CIRCUIT ACHIEVES SPEEDS OF 1 TRILLION CYCLES PER SECOND, EARNS GUINNESS WORLD RECORD



Accomplishments in Terahertz Electronics program could pave way for new areas of research and unforeseen applications in the sub-millimeter wave spectrum
Officials from Guinness World Records today recognized DARPA’s Terahertz Electronics program for creating the fastest solid-state amplifier integrated circuit ever measured. The ten-stage common-source amplifier operates at a speed of one terahertz (1012 GHz), or one trillion cycles per second—150 billion cycles faster than the existing world record of 850 gigahertz set in 2012.
“Terahertz circuits promise to open up new areas of research and unforeseen applications in the sub-millimeter-wave spectrum, in addition to bringing unprecedented performance to circuits operating at more conventional frequencies,” said Dev Palmer, DARPA program manager. “This breakthrough could lead to revolutionary technologies such as high-resolution security imaging systems, improved collision-avoidance radar, communications networks with many times the capacity of current systems and spectrometers that could detect potentially dangerous chemicals and explosives with much greater sensitivity.”
Developed by Northrop Grumman Corporation, the Terahertz Monolithic Integrated Circuit (TMIC) exhibits power gains several orders of magnitude beyond the current state of the art. Gain, which is measured logarithmically in decibels, similar to how earthquake intensity is measured on the Richter scale, describes the ability of an amplifier to increase the power of a signal from the input to the output. The Northrop Grumman TMIC showed a measured gain of nine decibels at 1.0 terahertz and eight decibels at 1.03 terahertz. By contrast, current smartphone technology operates at one to two gigahertz and wireless networks at 5.7 gigahertz
“Gains of six decibels or more start to move this research from the laboratory bench to practical applications—nine decibels of gain is unheard of at terahertz frequencies” said Palmer. “This opens up new possibilities for building terahertz radio circuits.”
For years, researchers have been looking to exploit the tremendously high-frequency band beginning above 300 gigahertz where the wavelengths are less than one millimeter. The terahertz level has proven to be somewhat elusive though due to a lack of effective means to generate, detect, process and radiate the necessary high-frequency signals.
Current electronics using solid-state technologies have largely been unable to access the sub-millimeter band of the electromagnetic spectrum due to insufficient transistor performance. To address the “terahertz gap,” engineers have traditionally used frequency conversion—converting alternating current at one frequency to alternating current at another frequency—to multiply circuit operating frequencies up from millimeter-wave frequencies. This approach, however, restricts the output power of electrical devices and adversely affects signal-to-noise ratio. Frequency conversion also increases device size, weight and power supply requirements.
DARPA has made a series of strategic investments in terahertz electronics through itsHiFIVE, SWIFT and TFAST programs. Each program built on the successes of the previous one, providing the foundational research necessary for frequencies to reach the terahertz threshold.