Terahertz tuning by core-shell nanoparticles irradiated by skew-cosh Gaussian lasers

Physica Scripta, Journal Year: 2024, Volume and Issue: 99(3), P. 035605 - 035605

Published: Jan. 24, 2024

Abstract Choosing two skew-cosh Gaussian beams, an analytical investigation of a medium having spherical and cylindrical core–shell nanoparticles (NPs) is performed for the generation tunable terahertz (THz) radiation. The core NPs considered to be made up silica which concentrically wrapped by graphite shell. basal planes / are taken in parallel or perpendicular direction with lasers electric field. In this phenomenon, incident beams provide nonlinear velocity electron cloud NPs, leading current hence THz emission. After obtaining expression current, field calculated making use Maxwell’s equations along effective permittivity governed radii shell NPs. Tunable radiations obtained judiciously varying order tune focus radiation, resonance peaks can shift towards higher frequencies, i.e., 10.4 49.4 THz, depending on longitudinal transverse plasmon resonances, respectively. parameters laser exploited achieving efficient

Language: Английский

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Ultrasoft Long-Lasting Reusable Hydrogel-Based Sensor Patch for Biosignal Recording

Biosensors, Journal Year: 2024, Volume and Issue: 14(8), P. 405 - 405

Published: Aug. 22, 2024

Here, we report an ultrasoft extra long-lasting, reusable hydrogel-based sensor that enables high-quality electrophysiological recording with low-motion artifacts. The developed can be used and stored in ambient environment for months before being reused. is made of a self-adhesive electrical-conductivity-enhanced hydrogel mounted Ecoflex-based frame. hydrogel’s conductivity was enhanced by incorporating polypyrrole (PPy), resulting 0.25 S m−1. Young’s modulus the only 12.9 kPa, it stretchable up to 190%. successfully electrocardiography (ECG) electromyography (EMG). Our results indicate using sensor, signal-to-noise ratio recorded signals improved comparison when medical-grade silver/silver chloride (Ag/AgCl) wet gel electrodes were (33.55 dB 22.16 dB). Due ultra-softness, high stretchability, self-adhesion conform skin and, therefore, shows low susceptibility motion. In addition, no sign irritation or allergic reaction, which usually occurs after long-term wearing Ag/AgCl on skin. Further, fabricated low-cost scalable fabrication process.

Language: Английский

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Terahertz Metamaterial Sensors: Design Theory, Optimization Approach, and Advancements in Biosensing Applications

Advanced Materials Technologies, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 14, 2024

Abstract Metamaterials (MMs), distinguished by their unique electromagnetic properties, offer significant advantages in the realm of terahertz (THz) biosensing and early disease diagnosis. The intense electric field confined within subwavelength volumes metallic MMs enhances interaction between light analytes. Q‐factor, sensitivity figure merit (FOM) are three critical direct parameters for quantitative evaluation sensor performance. Researchers pursuing enhancement these optimal design structures dimensions as well proper choice materials. Recently, dielectric perturbation theory is quantitatively calculated successfully utilized optimization THz sensors. Guided this theory, review focuses on principle sensors, various study how to improve fundamental specific application including functionalization process, fabrication Based methods results, future development sensors finally presented a perspective view.

Language: Английский

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Review of Bioplastics Characterisation by Terahertz Techniques in the View of Ensuring a Circular Economy

Photonics, Journal Year: 2023, Volume and Issue: 10(8), P. 883 - 883

Published: July 29, 2023

The increasing scarcity of natural resources, worsening global climate change, environmental degradation, and rising demand for food are forcing the biotechnology plastics industries to seek apply circular economy models that would lead a sustainable transition in production use bioplastics. Circular can improve economic productivity bio-based have positive impact on environment by reducing conventional plastic waste consumption petrochemical feedstocks production. In addition, some agricultural wastes potential be used as bioplastics reused. Terahertz (THz) systems already rubber non-destructive testing, detection, imaging, quality control. Several reports highlighted applications THz spectroscopy imaging polymer analysis characterisation. This is even greater with chemometric methods artificial intelligence algorithms. this review, we focus support transformation sector economy, particularly via from discuss characterisation biopolymers. results previous studies biopolymers frequency range summarised. Furthermore, using approaches such machine learning advanced analytical addition conventionally methods, discussed. review highlight technology contribute closed technological circles important areas related industries.

Language: Английский

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Study on the Influence of UV Light on Selective Antibacterial Activity of Silver Nanoparticle Synthesized Utilizing Protein/Polypeptide-Rich Aqueous Extract from The Common Walkingstick, Diapheromera femorata

Materials, Journal Year: 2024, Volume and Issue: 17(3), P. 713 - 713

Published: Feb. 2, 2024

Common walkingstick (Diapheromera femorata) aqueous extract (CWSAE) can induce the synthesis of useful bionanomaterials. CWSAE is rich in water-soluble organic compounds such as proteins and polypeptides that function reducing/stabilizing agents for nanoparticle formation from Ag+ ion precursors. The synthesized AgNPs exhibited a moderately uniform size, with majority falling within range 20-80 nm. These were UV-treated tested antibacterial to inhibit growth four pathogenic bacteria (Burkholderia cenocepacia K-56, Klebsiella pneumoniae ST258, Pseudomonas aeruginosa PAO1, Staphylococcus aureus USA300), well one common bacterium (Escherichia coli BW25113). disk diffusion test demonstrated significantly selectively inhibited USA300 P. aeruginosa, while showing small effect on other two species. This suggests potential application green-chemically selective agents. Furthermore, we studied effects short-term (1-2 min) long-term (5-30 UV treatment cytotoxicity found could depend duration exposure against certain bacteria.

Language: Английский

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Femtosecond X-ray snapshots reveal correlated displacements of specific distal atoms in a protein crystal

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: June 2, 2024

Abstract Protein dynamics is shaped by interactions between thermal fluctuations, external forces, and molecular structures. Thermal fluctuations have high frequencies are hence very challenging to quantify. We were able record femtosecond X-ray diffraction snapshots determine atomic displacements of crystalline bovine trypsin atoms either in the native steady state or a transient initiated short THz pulse, results which interpreted with numerical simulations. In absence pulses, specific distal exhibited correlated movements. Under influence fields, simulations demonstrated slight enhancement displacement correlations. The experimental revealed contrasting response where measured not solely determined atom position, but also influenced type. These findings call for reinterpretation dynamic properties inherent folded protein structures physical principles behind formation assemblies. To this end, theoretical model was developed lattice deformations local excitations entraining (squeezed) coherent state, explaining emergence accounts magnitudes through balance harmonic anharmonic coupling forces.

Language: Английский

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Advancing Aerospace Inspection With Terahertz Technology

Advances in mechatronics and mechanical engineering (AMME) book series, Journal Year: 2024, Volume and Issue: unknown, P. 195 - 211

Published: May 17, 2024

The chapter discusses the advancements in technology security and aerospace inspection, focusing on terahertz (THz) technology. THz, a mix of radio light waves, is used detection hazardous compounds weapons, enabling accurate chemical identification, high-bandwidth communication, imaging, material analysis. However, Terahertz Gap presents challenges, leading to development THz Photoconductive Antennas (THz-PCAs), quantum cascade lasers (QCLs), frequency combs, optical photonic oscillators (OPOs), superconducting bolometers, field-effect transistors. revolutionizing non-destructive industrial quality control aviation, space exploration, non-invasive medical imaging. Challenges include cost, size, complexity, lack standardization. This suggests reducing costs, miniaturization,

Language: Английский

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Spectroscopic evidence of the radioresistance of Chroococcidiopsis biosignatures: A combined Raman, FT-IR and THz-TDs spectroscopy study

Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy, Journal Year: 2022, Volume and Issue: 288, P. 122148 - 122148

Published: Nov. 24, 2022

In the last decades, Mars has been widely studied with on-site missions and observations, showing a planet that could have hosted life in past. For this reason, recent future space on red will search for traces of past and, possibly, present life. As basis these missions, Space Agencies, such as European Agency, conducted many experiments living organisms, studying their behavior extraterrestrial conditions, learning to recognize biosignatures techniques remotely controllable Raman spectroscopy. Among radioresistant cyanobacterium Chroococcidiopsis was irradiated during STARLIFE campaign strong radiative insults. article we investigated using spectroscopy extended characterization its response stress mid- Infrared Terahertz spectral region Fourier Transform InfraRed (FT-IR) Time Domain (THz- TDs), which demonstrates compatibility suitability missions.

Language: Английский

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Observation of Spurious Spectral Features in Mixed-Powder Compressed Pellets Measured by Terahertz Time-Domain Spectroscopy

IEEE Transactions on Terahertz Science and Technology, Journal Year: 2023, Volume and Issue: 13(5), P. 569 - 572

Published: June 27, 2023

Spurious loss features were observed in mixed-powder compressed pellets measured transmission using terahertz time-domain spectroscopy. Loss identified two types of pellets: polytetrafluoroethylene (PTFE)-glass microspheres and PTFE-lactose. The found to be dependent on grain size concentration. An explanation is proposed, based varying optical thickness the sample material.

Language: Английский

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Introduction to the Biological Effects of Terahertz Radiation

IntechOpen eBooks, Journal Year: 2023, Volume and Issue: unknown

Published: June 29, 2023

Terahertz (THz) radiation has been noted to affect biological organisms a unique degree with various effects ranging from modifications brought protein activity epigenetic changes that lead altered metabolism or reproduction. These are classified into thermal and non-thermal, the former being caused by THz’s capacity induce localised while latter involves more complex interactions cells’ macromolecules which poorly understood. Terahertz’s ability enhance actin polymerisation alter gene expression leads number of possible applications in agriculture, as it observed certain plant species have higher growth speeds post-exposure, medicine, cancer’s rapid division possibly slowed down.

Language: Английский

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