scholarly journals The Gyrotrons as Promising Radiation Sources for THz Sensing and Imaging

2020 ◽  
Vol 10 (3) ◽  
pp. 980 ◽  
Author(s):  
Toshitaka Idehara ◽  
Svilen Petrov Sabchevski ◽  
Mikhail Glyavin ◽  
Seitaro Mitsudo
Keyword(s):  
Continuous Wave ◽  
Current Status ◽  
Resonance Spectroscopy ◽  
Spectroscopic Techniques ◽  
The Road ◽  
Radiation Sources ◽  
Spin Resonance ◽  
Thz Sensing ◽  
New Applications ◽  
And Control

The gyrotrons are powerful sources of coherent radiation that can operate in both pulsed and CW (continuous wave) regimes. Their recent advancement toward higher frequencies reached the terahertz (THz) region and opened the road to many new applications in the broad fields of high-power terahertz science and technologies. Among them are advanced spectroscopic techniques, most notably NMR-DNP (nuclear magnetic resonance with signal enhancement through dynamic nuclear polarization, ESR (electron spin resonance) spectroscopy, precise spectroscopy for measuring the HFS (hyperfine splitting) of positronium, etc. Other prominent applications include materials processing (e.g., thermal treatment as well as the sintering of advanced ceramics), remote detection of concealed radioactive materials, radars, and biological and medical research, just to name a few. Among prospective and emerging applications that utilize the gyrotrons as radiation sources are imaging and sensing for inspection and control in various technological processes (for example, food production, security, etc). In this paper, we overview the current status of the research in this field and show that the gyrotrons are promising radiation sources for THz sensing and imaging based on both the existent and anticipated novel techniques and methods.

scholarly journals Tuning flavin environment to detect and control light-induced conformational switching in Drosophila cryptochrome

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Siddarth Chandrasekaran ◽  
Connor M. Schneps ◽  
Robert Dunleavy ◽  
Changfan Lin ◽  
Cristina C. DeOliveira ◽  
...  
Keyword(s):  
Side Reactions ◽  
Resonance Spectroscopy ◽  
Conformational Switching ◽  
Spin Resonance ◽  
Degradation Activity ◽  
Recognition Motifs ◽  
Cellular Turnover ◽  
Control Light ◽  
Dynamics Simulations ◽  
And Control

AbstractLight-induction of an anionic semiquinone (SQ) flavin radical in Drosophila cryptochrome (dCRY) alters the dCRY conformation to promote binding and degradation of the circadian clock protein Timeless (TIM). Specific peptide ligation with sortase A attaches a nitroxide spin-probe to the dCRY C-terminal tail (CTT) while avoiding deleterious side reactions. Pulse dipolar electron-spin resonance spectroscopy from the CTT nitroxide to the SQ shows that flavin photoreduction shifts the CTT ~1 nm and increases its motion, without causing full displacement from the protein. dCRY engineered to form the neutral SQ serves as a dark-state proxy to reveal that the CTT remains docked when the flavin ring is reduced but uncharged. Substitutions of flavin-proximal His378 promote CTT undocking in the dark or diminish undocking in the light, consistent with molecular dynamics simulations and TIM degradation activity. The His378 variants inform on recognition motifs for dCRY cellular turnover and strategies for developing optogenetic tools.

scholarly journals Development of planar microstrip resonators for electron spin resonance spectroscopy

2020 ◽  
Vol 90 (3) ◽  
pp. 31001 ◽  
Author(s):  
Subhadip Roy ◽  
Sagnik Saha ◽  
Jit Sarkar ◽  
Chiranjib Mitra
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Continuous Wave ◽  
Characteristic Impedance ◽  
Spectroscopic Studies ◽  
Design Parameters ◽  
Resonance Spectroscopy ◽  
Spin Resonance ◽  
Microstrip Resonators ◽  
Transverse Electromagnetic

This work focuses on the development of planar microwave resonators for use in electron spin resonance spectroscopic studies. Two half-wavelength microstrip resonators of different geometrical shapes, namely straight ribbon and omega, are fabricated on commercially available microwave laminates. Both resonators have a characteristic impedance of 50 Ω. We have performed electromagnetic field simulations for the resonators and have extracted design parameters that were used for fabrication. The effect of the geometry on the quasi-transverse electromagnetic (quasi-TEM) modes of the resonators is noted from simulation results. The fabrication is done using optical lithography in which laser printed photomasks are used. This prototyping technique allows us to fabricate resonators in a few hours with accuracy up to 6 mils. The resonators are characterized using a Vector Network Analyzer. The fabricated resonators are used in a home built low-temperature continuous wave electron spin resonance (CW-ESR) spectrometer which operates in S-band. It captures the absorption spectrum of the free radical DPPH, at both room temperature and 77 K. The measured g-factor using our resonators is consistent with the values reported in literature. Spin sensitivity of 1015 spins/gauss is achieved at 77 K. The designed resonators will be used in setting up a pulsed electron spin resonance spectrometer by suitably modifying the CW-ESR spectrometer.

Portable Life Support System: Current Status and Future Perspectives

2020 ◽  
Vol 14 (1) ◽  
pp. 12-28
Author(s):  
Jingang Jiang ◽  
Yihao Chen ◽  
Xuefeng Ma ◽  
Yongde Zhang ◽  
Zhiyuan Huang ◽  
...  
Keyword(s):  
Support System ◽  
Life Support ◽  
Support Systems ◽  
Vital Signs ◽  
Current Status ◽  
Life Support System ◽  
Life Support Systems ◽  
Special Circumstances ◽  
And Control ◽  
Further Development

Background: Portable life support system is used in the battlefield, disaster and in other special circumstances such as in space exploration, and underground survey to give the wounded a life support. The most dangerous period for the injured is the first hour after an injury, which is a crucial time for treatment. If the patient's vital signs were stabilized, more than 40% of the injured could be saved. The staff can efficiently complete the task if they get effective and stable vital signs during the operation. Therefore, in order to reduce the risk of disaster and battlefield mortality to improve operational safety and efficiency, it is necessary to study the portable life support system. Objective: The study aimed to provide an overview of recent portable life support system and its characteristics and design. Methods: This paper introduces the patents and products related to a portable life support system, and its characteristics and application. Results: This paper summarizes five kinds of portable life support systems which are box type, stretcher type, bed type, backpack type and mobile type. Moreover, the characteristics of different portable life support systems are analyzed. The paper expounds the problems of different types of portable life support systems and puts forward improvement methods to solve the problems. Finally, the paper points out the future development of the system. Conclusion: Portable life support system plays an increasingly important role in health care. In terms of the structure, function and control, further development and improvements are needed, along with the research on portable life support system.

scholarly journals Membrane condenser as emerging technology for water recovery and gas pre-treatment: current status and perspectives

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Adele Brunetti ◽  
Francesca Macedonio ◽  
Giuseppe Barbieri ◽  
Enrico Drioli
Keyword(s):  
Current Status ◽  
Innovative Technology ◽  
Water Recovery ◽  
Treatment Unit ◽  
Treatment Stage ◽  
Treatment Technologies ◽  
Pre Treatment ◽  
And Control

Abstract The recent roadmap of SPIRE initiative includes the development of “new separation, extraction and pre-treatment technologies” as one of the “key actions” for boosting sustainability, enhancing the availability and quality of existing resources. Membrane condenser is an innovative technology that was recently investigated for the recovery of water vapor for waste gaseous streams, such as flue gas, biogas, cooling tower plumes, etc. Recently, it has been also proposed as pre-treatment unit for the reduction and control of contaminants in waste gaseous streams (SOx and NOx, VOCs, H2S, NH3, siloxanes, halides, particulates, organic pollutants). This perspective article reports recent progresses in the applications of the membrane condenser in the treatment of various gaseous streams for water recovery and contaminant control. After an overview of the operating principle, the membranes used, and the main results achieved, the work also proposes the role of this technology as pre-treatment stage to other separation technologies. The potentialities of the technology are also discussed aspiring to pave the way towards the development of an innovative technology where membrane condenser can cover a key role in redesigning the whole upgrading process.

Current status, problems and control strategies of water resources pollution in China

Water Policy ◽  
2014 ◽  
Vol 17 (3) ◽  
pp. 423-440 ◽  
Author(s):  
Lei Wu ◽  
Tong Qi ◽  
Dan Li ◽  
Huijuan Yang ◽  
Guoqing Liu ◽  
...  
Keyword(s):  
Water Pollution ◽  
Control Strategies ◽  
Water Environment ◽  
Underground Water ◽  
National Standard ◽  
Current Status ◽  
Food Borne ◽  
Major River ◽  
And Control ◽  
Research And Policy

The surface water of 10 major river systems across China has been under intermediate pollution with striking eutrophication problems in major lakes (reservoirs). More data from the Ministry of Environmental Protection of China showed that underground water in 57% of monitoring sites across Chinese cities was polluted or extremely polluted. Rural water pollution, the rising number of incidents of industrial pollution, outdated sewerage systems, and the overuse of pesticides and chemical fertilizers also endanger the health of rural inhabitants in China. Nearly 0.2 billion rural residents could not use drinking water in accordance with the national standard, and there were reports of ‘cancer villages' and food-borne diseases (cancer village refers to a village where a certain proportion of its inhabitants suffer from the same kind of cancer or where there is a hike in cancer incidence in that area). This study aims to raise awareness of the prevention and control of water pollution and to propose a set of national research and policy initiatives for the future safety of the water environment in China.

scholarly journals Spectroscopic Study of the Molecular Structure of the New Hybrid with a Potential Two-Way Antibacterial Effect

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1442
Author(s):  
Dorota Kowalczuk ◽  
Agata Gładysz ◽  
Monika Pitucha ◽  
Daniel M. Kamiński ◽  
Agnieszka Barańska ◽  
...  
Keyword(s):  
Spectroscopic Study ◽  
Good Alternative ◽  
Structure Characterization ◽  
Resonance Spectroscopy ◽  
Spectroscopic Techniques ◽  
Bacterial Strains ◽  
Active Components ◽  
Hybrid Compound ◽  
Coordination Sites ◽  
Almost All

Bacterial strains become resistant to almost all classes of antibiotics, which makes it necessary to look for new substitutes. The non-absorbable ciprofloxacin–biguanide bismuth complex, used locally, may be a good alternative to a conventional therapy. The purpose of this study was to study the structure of the proposed ciprofloxacin (CIP) -bismuth(III)—chlorhexidine (CHX) composite (CIP-Bi-CHX). The spectroscopic techniques such as UV-VIS (ultraviolet-visible) spectroscopy, FTIR (Fourier-transform infrared) spectroscopy and NMR (Nuclear Magnetic Resonance) spectroscopy were used for structure characterization of the hybrid compound. The performed analysis confirmed the presence of the two active components—CIP and CHX and revealed the possible coordination sites of the ligands with bismuth ion in the metallo-organic structure. Spectroscopic study showed that the complexation between Bi(III) and CIP occurs through the carboxylate and ketone groups of the quinolone ring, while CHX combines with the central ion via the biguanide moieties.

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