ARTICLE | doi:10.20944/preprints201711.0155.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: millimeter-wave; radiometer; sequential lobing
Online: 23 November 2017 (11:29:03 CET)
The paper investigates the theory of operation of a passive millimeter-wave seeker sensor using fast electronic sequential-lobing technique and the experimental validation obtained through laboratory trials. The paper analyzes in detail the theoretical performance of a difference channel sensor and a pseudo-monopulse sensor deriving agile formulas for the estimation of target angular tracking accuracy and the subsequent experimental validation.
Subject: Life Sciences, Biophysics Keywords: non-ionizing radiation; millimeter waves; novel biomedical applications; yeast; non-invasive devices
Online: 17 September 2020 (07:08:47 CEST)
Nonionizing millimeter-waves (MMW) are reported to interact with cells in a variety of ways. Possible mechanisms of the inhibited cell division effect were investigated using 85-105 GHz MMW irradiation within the ICNIRP (International Commission on Non-Ionizing Radiation Protection) non-thermal 20 mW/cm2 safety standards. ~1.0 mW/cm2 exposure over 5-6 hours treatment on 50 cells/μl samples of Saccharomyces cerevisiae model organism, resulted in 62% growth rate reduction compared to control (sham). The effect was specific for 85-105 GHz range and energy dose and cell density dependent. Irradiation of wild type and Δrad52 (DNA damage repair gene) deletion cells presented no differences of colony growth profiles indicating non-thermal MMW treatment does not cause genetic alterations. Dose versus response relations studied using a standard horn antenna (~1.0 mW/cm2) and compared to that of a compact waveguide (17.17 mW/cm2) for increased power delivery resulted in complete termination of cell division via non-thermal processes supported by temperature rise measurements. Combinations of MMW mediated Structure Resonant Energy Transfer (SRET), membrane modulations eliciting signaling effects, and energetic resonance with biomolecules were indicated to be responsible for the observations reported. Our results provide novel mechanistic insights enabling innovative applications of nonionizing radiation procedures for eliciting targeted biomedical outcomes.
ARTICLE | doi:10.20944/preprints202003.0439.v2
Subject: Physical Sciences, Applied Physics Keywords: non-ionizing radiation; lung cancer; millimeter waves; cell morphology; 75-110 GHz
Online: 17 April 2020 (12:49:49 CEST)
Efficiently targeted cancer therapy without causing detrimental side effects is necessary for alleviating patient care and improving survival rates. This paper presents observations of morphological changes in H1299 human lung cancer cells following W-band MMW irradiation (75 – 105 GHz) at a non-thermal power density of 0.2 mW/cm2, investigated over 14 days of subsequent physiological incubation following exposure. Microscopic analyses of physical parameters measured indicate MMW irradiation induces significant morphological changes characteristic of apoptosis and senescence. The Immediate short-term responses translate into long-term effects, retained over the duration of the experiment(s); reminiscent of the phenomenon of Accelerated Cellular Senescence (ACS) achieving terminal tumorigenic cell growth. Further, results were observed to be treatment-specific in energy (dose) dependent manner and were achieved without the use of chemotherapeutic agents, ionizing radiation or thermal ablation employed in conventional methods; thereby overcoming associated side effects. Adaptation of the experimental parameters of this study for clinical oncology concomitant with current developmental trends of non-invasive medical endoscopy alleviates MMW therapy as an effective treatment procedure for human non-small cell lung cancer (NSCLC).
Subject: Engineering, Electrical & Electronic Engineering Keywords: millimeter wave imaging; orthogonal coded multiplexing; compressed sensing; real-time imaging; dynamic range
Online: 10 November 2019 (09:40:50 CET)
Millimeter wave wide-band imaging is widely studied for a variety of applications. However real-time millimeter wave wide-band imaging at frequencies above 30GHz for moving targets in a large field of view has not been realized commercially. A 2D sparse array with transmitter multiplexing is a promising solution to this problem. In this article, a method combining compressed sensing and orthogonal coded multiplexing was proposed, and the imaging performance was analyzed for different reconstruction algorithms and observation matrices by imaging simulation for a continuous object. Also the influence on the dynamic range of the original signal introduced by orthogonal coded multiplexing was studied. This work demonstrated that the proposed method was effective in reconstructing the image with a real-time capability. It is shown that different algorithms and matrices resulted in distinct performances, while the evaluation parameter selection also played a role. This work provided useful instructions for both the hardware and software design of a real-time 3D millimeter wave imaging system in the future.
ARTICLE | doi:10.20944/preprints201703.0103.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: radar 3D imaging; synthetic aperture radar; millimeter wave radar; remote sensing; compressed sensing; inverse Radon transform; portable
Online: 15 March 2017 (08:44:25 CET)
In this paper, a new millimeter wave 3D imaging radar is proposed. The user just needs to move the radar along a circular track, a high resolution 3D imaging can be generated. The proposed radar uses the movement of itself to synthesize a large aperture in both the azimuth and elevation directions. It can utilize inverse Radon transform to resolve 3D imaging. To improve the sensing result, compressed sensing approach is further investigated. The simulation and experimental result further illustrated the design. Because a single transceiver circuit is needed, a light, affordable and high resolution 3D mmWave imaging radar is illustrated in the paper.
ARTICLE | doi:10.20944/preprints201806.0263.v1
Subject: Engineering, Other Keywords: Multi-tier hybrid caching networks; stochastic geometry; millimeter wave; average successful delivery probability; performance analysis
Online: 15 June 2018 (15:24:27 CEST)
In the fifth generation communication system, millimeter wave (mmWave) networks will coexist with traditional micro wave (μWave) networks, which allows for higher data transmission rate and better user experience. In this paper, we give a comprehensive framework of mathematical models and analytical methods for multi-tier mmWave and μWave hybrid caching networks based on stochastic geometry. We propose an association strategy by assuming average biased-received power association and Rayleigh fading. Accordingly, by using a D-ball approximating blockage model of mmWave networks, expressions of the cell association probability and the coverage probability of the hybrid networks are derived. Also, we use the average successful delivery probability as the performance metric to analyze the existing caching placement strategies. Simulation results validate the accuracy of our analytical conclusions.
ARTICLE | doi:10.20944/preprints202201.0149.v3
Subject: Life Sciences, Cell & Developmental Biology Keywords: Mussel; vitality; motility; millimeter waves; SAR
Online: 28 February 2022 (09:55:17 CET)
Recently, a rising use of wireless internet technologies has been demonstrated. The devices 18 which use these technologies emit in new spectral regions an electromagnetic radiation (EMFs) 19 which could interact with the male reproductive system. The aim of this study was to investigate in 20 vitro influence of electromagnetic fields at 27 GHz on sperm quality in Mytilus galloprovincialis. 21 Sperm samples, were collected from sexually mature males of M. galloprovincialis and placed in sea- 22 water. Once evaluated the number and quality of spermatozoa, sperm cells were exposed to elec- 23 tromagnetic fields radiated by a pyramidal horn antenna. The effect of exposure was evaluated after 24 10, 20, 30, 40 and 60 minutes with light microscope and using Eosin test. Ten replications were per- 25 formed for each time series, and statistical analysis was carried out byt-test. A significative decrease 26 in sperm motility was observed after 10 minutes of exposure and after 30 minutes most of sperms 27 were immobile and not vital. This study provides useful data on potential ecological impact of the 28 5G high-band on animal fertility, whose effect is currently under investigation.
ARTICLE | doi:10.20944/preprints202201.0136.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: millimeter waves; zebrafish; DanioScope; biomarkers of exposure; SAR.
Online: 11 January 2022 (12:22:42 CET)
5G technology is evolving to satisfy several service requirements favoring high data-rate connections and lower latency times than current ones (< 1ms). 5G systems use different frequency bands of the radio wave spectrum, taking advantage of higher frequencies than previous mobile radio generations. In order to guarantee a capillary coverage of the territory for high reliability applications, it will be necessary to install a large number of repeaters because higher frequencies waves have a lower capacity to propagate in free space. Following the introduction of this new technology, there has been a growing concern about possible harmful effects on human health. The aim of this study is investigating possible short term effects induced by 5G-millimeter waves on embryonic development of Danio rerio. We have exposed fertilized eggs to 27 GHz frequency, 9.7 mW/cm2 incident power density, 23 dbm and have measured several endpoints every 24 hours. The exposure to electromagnetic fields at 27 GHz (5G) caused no significant impacts on mortality nor on morphology because the exposed larvae showed a normal detachment of the tail, presence of heart-beat and well-organised somites. A weak positivity on exposed larvae has been highlighted by immunohistochemical analysis.
ARTICLE | doi:10.20944/preprints201611.0010.v1
Subject: Earth Sciences, Atmospheric Science Keywords: millimeter-wavelength cloud radar; attenuation correction; dual-radar; data fusion
Online: 1 November 2016 (10:05:18 CET)
In order to correct attenuated millimeter-wavelength (Ka-band) radar data and address the problem of instability, an attenuation correction methodology (attenuation correction with variation trend constraint; VTC) was developed. Using synchronous observation conditions and multi-band radars, the VTC method adopts the variation trends of reflectivity in X-band radar data captured with wavelet transform as a constraint to adjust reflectivity factors of millimeter-wavelength radar. The correction was evaluated by comparing reflectivities obtained by millimeter-wavelength cloud radar and X-band weather radar. Experiments showed that attenuation was a major contributory factor in the different reflectivities of the two radars when relatively intense echoes exist, and the attenuation correction developed in this study significantly improved data quality for millimeter-wavelength radar. Reflectivity differences between the two radars were reduced and reflectivity correlations were enhanced. Errors caused by attenuation were eliminated, while variation details in the reflectivity factors were retained. The VTC method is superior to the bin-by-bin method in terms of correction amplitude and can be used for attenuation correction of shorter wavelength radar assisted by longer wavelength radar data.
ARTICLE | doi:10.20944/preprints201707.0060.v1
Subject: Earth Sciences, Atmospheric Science Keywords: vertical air velocity; millimeter-wave cloud radar; convective cloud; Tibetan Plateau
Online: 21 July 2017 (04:58:56 CEST)
In the summertime, convections occur frequently over the Tibetan Plateau (TP) because of the large dynamic and thermal effects of the landmass. Measurements of vertical air velocity in convective cloud are useful for advancing our understanding of the dynamic and microphysical mechanisms of clouds and can be used to improve the parameterization of current numerical models. This paper presents a technique for retrieving high-resolution vertical air velocity from convective cloud over the TP, by using Doppler spectra from a vertically pointing Ka-band cloud radar. The method is based on the development of a “small-particle-traced” idea and the necessary data processing and uses three modes of radar. Spectral broadening corrections, uncertainty estimations, and result merging are used to ensure accurate results. Qualitative analysis of two typical convective cases shows that the retrievals are reliable and agree with the expectant results inferred from other radar measurements. A quantitative retrieval of vertical air motion from a ground-based optical disdrometer is used to preliminarily validate our radar-derived results. The comparison illustrates that while the data trends from the two methods of retrieval are similar, with the updrafts and downdrafts coinciding, cloud radar has a much higher resolution and can reveal the small-scale variation of vertical air motion.
ARTICLE | doi:10.20944/preprints202011.0032.v3
Subject: Life Sciences, Biochemistry Keywords: Non-ionizing Radiation; Millimeter waves; Novel biomedical applications; Yeast; Non-invasive devices
Online: 16 April 2021 (14:52:04 CEST)
Nonionizing millimeter-waves (MMW) interact with cells in a variety of ways. Here the inhibited cell division effect was investigated using 85-105 GHz MMW irradiation within the ICNIRP (International Commission on Non-Ionizing Radiation Protection) non-thermal 20 mW/cm2 safety standards. Irradiation using a power density of about 1.0 mW/cm2 , SAR over 5-6 hours on 50 cells/μl samples of Saccharomyces cerevisiae model organism resulted in 62% growth rate reduction compared to the control (sham). The effect was specific for 85-105 GHz range, and was energy and cell density dependent. Irradiation of wild type and Δrad52 (DNA damage repair gene) deleted cells presented no differences of colony growth profiles indicating non-thermal MMW treatment does not cause permanent genetic alterations. Dose versus response relations studied using a standard horn antenna (~1.0 mW/cm2) and compared to that of a compact waveguide (17.17 mW/cm2) for increased power delivery resulted in complete termination of cell division via non-thermal processes supported by temperature rise measurements. We have shown that non-thermal MMW radiation has potential for future use in treatment of yeast related diseases and other targeted biomedical outcomes.
ARTICLE | doi:10.20944/preprints202111.0514.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: millimeter bands; fifth Generation; Handover; Deep Reinforcement Learning; and Jump Markov Linear System
Online: 29 November 2021 (07:50:19 CET)
The fifth Generation (5G) mobile networks use millimeter Waves (mmWaves) to offer giga bit data rates. However, unlike microwaves, mmWave links are prone to user and topographic dynamics. They easily get blocked and end up forming irregular cell patterns for 5G. This in turn cause too early, too late, or wrong handoffs (HOs). To mitigate HO challenges, sustain connectivity and avert unnecessary HO, we propose a HO scheme based on Jump Markov Linear System (JMLS) and Deep Reinforcement Learning (DRL). JMLS is widely known to account for abrupt changes in system dynamics. DRL likewise emerges as an artificial intelligence technique for learning highly dimensional and time-varying behaviors. We combine the two techniques to account for time-varying, abrupt, and irregular changes in mmWave link behaviour by predicting likely deterioration patterns of target links. The prediction is optimized by meta training techniques that also reduces training sample size. Thus, the JMLS-DRL platform formulates intelligent and versatile HO policies for 5G. Results show our proposed prediction scheme about target link behavior post HO to be highly reliable. The scheme also averts unnecessary HOs thus ably supports longer dew time.
ARTICLE | doi:10.20944/preprints201807.0149.v1
Subject: Physical Sciences, Astronomy & Astrophysics Keywords: planetary nebulae; AGB & post-AGB stars; binarity; accretion disks; jets; mass-loss; circumstellar matter; (sub)millimeter interferometry; ultraviolet radiation; X-rays
Online: 9 July 2018 (13:58:51 CEST)
It is widely believed that the dramatic transformation of the spherical outflows of AGB stars into the extreme aspherical geometries seen during the planetary nebula (PN) phase is linked to binarity and driven by the associated production of fast jets and central disks/torii. The key to understanding the engines that produce these jets and the jet-shaping mechanisms lies in the study of objects in transition between the AGB and PN phases. I discuss the results of our recent studies with high-angular-resolution (with ALMA & HST) and at high-energies (with GALEX, XMM-Newton & Chandra) of several such objects, which reveal new details of close binary interactions and high-speed outflows. These include two PPNe (the Boomerang Nebula and IRAS16342-3814), and the late carbon star, V Hya. The Boomerang is notable for a massive, high-speed outflow that has cooled below the microwave background temperature, making it the coldest object in the Universe. IRAS16342 is the prime example of the class of water-fountain PPNe (very young PPNe with high-velocity H2O masers) and shows the signature of a precessing jet. V Hya ejects high-speed bullets every 8.5 years associated with the periastron passage of a companion in an eccentric orbit. I discuss our work on AGB stars with strongly-variable high-energy (FUV, X-ray) emission, suggesting that these objects are in the early stages of binary interactions that result in the formation of accretion disks and jets.