Timber modification by radio wave technology

2019 ◽  
Author(s):  
Christian Pfütze
Keyword(s):  
Radio Wave ◽  
Molecular Level ◽  
Positive Influence ◽  
Thermal Modification ◽  
Microwave Oven ◽  
Water Molecules ◽  
Radio Waves ◽  
Natural Conditions ◽  
Treated Timber ◽  
Hygric Properties

<p>The following paper describes how radio wave thermal modification at temperatures above 160°C can improve the durability of timber. It also broadens possible applications in areas where the timber decays faster under natural conditions. During the process, cellulose areas are modified to absorb less water. The treated timber is more resistant to decaying fungi. The heat required for this process is generated by polarization at a molecular level, similar to a microwave oven. However, the frequency of the radio and microwaves are different. (The frequency of radio and microwave are 13.56MHz and 2.45GHz respectively.) Radio waves have an advantage of higher permeability by several meters whereas microwaves can only heat a few centimeters. It is also possible to generate temperatures greater than 100°C, due to the frequency of radio waves polarizing water molecules and achieving ionic polarization. Therefore, it is possible to heat dry materials. The modified timber samples are analyzed for mechanical und hygric properties. The results show a positive influence on hydrologic properties by improving durability.</p>

scholarly journals Sensing Framework for the Internet of Actors in the Value Co-Creation Process with a Beacon-Attachable Indoor Positioning System

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 83
Author(s):  
Keiichi Zempo ◽  
Taiga Arai ◽  
Takuya Aoki ◽  
Yukihiko Okada
Keyword(s):  
Radio Wave ◽  
Indoor Positioning ◽  
Measurement Range ◽  
Pulse Interval ◽  
Retail Stores ◽  
Positioning System ◽  
Radio Waves ◽  
Positioning Systems ◽  
Environment Recognition ◽  
Indoor Positioning System

To evaluate and improve the value of a service, it is important to measure not only the outcomes, but also the process of the service. Value co-creation (VCC) is not limited to outcomes, especially in interpersonal services based on interactions between actors. In this paper, a sensing framework for a VCC process in retail stores is proposed by improving an environment recognition based indoor positioning system with high positioning performance in a metal shelf environment. The conventional indoor positioning systems use radio waves; therefore, errors are caused by reflection, absorption, and interference from metal shelves. An improvement in positioning performance was achieved in the proposed method by using an IR (infrared) slit and IR light, which avoids such errors. The system was designed to recognize many and unspecified people based on the environment recognition method that the receivers had installed, in the service environment. In addition, sensor networking was also conducted by adding a function to transmit payload and identification simultaneously to the beacons that were attached to positioning objects. The effectiveness of the proposed method was verified by installing it not only in an experimental environment with ideal conditions, but posteriorly, the system was tested in real conditions, in a retail store. In our experimental setup, in a comparison with equal element numbers, positioning identification was possible within an error of 96.2 mm in a static environment in contrast to the radio wave based method where an average positioning error of approximately 648 mm was measured using the radio wave based method (Bluetooth low-energy fingerprinting technique). Moreover, when multiple beacons were used simultaneously in our system within the measurement range of one receiver, the appropriate setting of the pulse interval and jitter rate was implemented by simulation. Additionally, it was confirmed that, in a real scenario, it is possible to measure the changes in movement and positional relationships between people. This result shows the feasibility of measuring and evaluating the VCC process in retail stores, although it was difficult to measure the interaction between actors.

scholarly journals Perspective Ground-based Method for Diagnostics of the Lower Ionosphere and the Neutral Atmosphere

2013 ◽  
Vol 22 (1) ◽  
Author(s):  
N. V. Bakhmetieva ◽  
G. I. Grigoriev ◽  
A. V. Tolmacheva
Keyword(s):  
Radio Wave ◽  
High Power ◽  
Relative Concentration ◽  
Spectral Characteristics ◽  
Lower Ionosphere ◽  
Internal Gravity Waves ◽  
Spatial Period ◽  
Neutral Atmosphere ◽  
Radio Waves ◽  
D Region

AbstractWe present a new perspective ground-based method for diagnostics of the ionosphere and atmosphere parameters. The method uses one of the numerous physical phenomena observed in the ionosphere illuminated by high-power radio waves. It is a generation of the artificial periodic irregularities (APIs) in the ionospheric plasma. The APIs were found while studying the effects of ionospheric high-power HF modification. It was established that the APIs are formed by a standing wave that occurs due to interference between the upwardly radiated radio wave and its reflection off the ionosphere. The API studies are based upon observation of the Bragg backscatter of the pulsed probe radio wave from the artificial periodic structure. Bragg backscatter occurs if the spatial period of the irregularities is equal to half a wavelength of the probe signal. The API techniques makes it possible to obtain the following information: the profiles of electron density from the lower D-region up to the maximum of the F-layer; the irregular structure of the ionosphere including split of the regular E-layer, the sporadic layers; the vertical velocities in the D- and E-regions of the ionosphere; the turbulent velocities, turbulent diffusion coefficients and the turbopause altitude; the neutral temperatures and densities at the E-region altitudes; the parameters of the internal gravity waves and their spectral characteristics; the relative concentration of negative oxygen ions in the D-region. Some new results obtained by the API technique are discussed.

scholarly journals Velocity of radio waves in glaciers as an indicator of their hydrothermal state, structure and regime

1993 ◽  
Vol 39 (132) ◽  
pp. 373-384 ◽  
Author(s):  
Yu. Ya. Macheret ◽  
M. Yu. Moskalevsky ◽  
E.V. Vasilenko
Keyword(s):  
Experimental Data ◽  
Radio Wave ◽  
Water Content ◽  
Low Frequency ◽  
Wide Angle ◽  
Radio Waves ◽  
State Structure ◽  
Mountain Ridge ◽  
Wave Velocities

AbstractThe results of measurements of radio-wave velocities (RWV) by wide-angle reflection (WAR) methods in the temperate Abramov Glacier in the Alai Mountain Ridge and the “two-layered” sub-polar Fridtjovbreen and Hansbreen on Svalbard using a low-frequency (2–13 MHz) radar are considered and discussed. The experimental data obtained and the data from the literature show that the values of RWV could be a good indicator of the hydrothermal state of glaciers. As such, these data enable the identification of cold, temperate and transitional (two-layered) glaciers, and can be used for estimation of the water content in glaciers and changes in the hydrothermal state.

The role of natural E-region plasma turbulence in the enhanced absorption of HF radio waves in the auroral ionosphere:Implications for RF heating of the auroral electrojet

1994 ◽  
Vol 12 (4) ◽  
pp. 316-332 ◽  
Author(s):  
T. R. Robinson
Keyword(s):  
Radio Wave ◽  
Electromagnetic Waves ◽  
Auroral Electrojet ◽  
Radio Waves ◽  
Electrostatic Waves ◽  
Enhanced Absorption ◽  
Heating Effects ◽  
Wave Heating ◽  
Radio Wave Absorption ◽  
E Region

Abstract. Physical processes which affect the absorption of radio waves passing through the auroral E-region when Farley-Buneman irregularities are present are examined. In particular, the question of whether or not it is legitimate to include the anomalous wave-enhanced collision frequency, which has been used successfully to account for the heating effects of Farley-Buneman waves in the auroral E-region, in the usual expression for the radio-wave absorption coefficient is addressed. Effects also considered are those due to wave coupling between electromagnetic waves and high-frequency electrostatic waves in the presence of Farley-Buneman irregularities. The implications for radio-wave heating of the auroral electrojet of these processes are also discussed. In particular, a new theoretical model for calculating the effects of high-power radio-wave heating on the electron temperature in an electrojet containing Farley-Buneman turbulence is presented.

scholarly journals A Novel Method for Prediction of Attenuation of Millimeter Waves by Fog and Smoke

2019 ◽  
Vol 8 (3) ◽  
pp. 2080-2085
Keyword(s):  
Wave Propagation ◽  
Water Vapor ◽  
Radio Wave ◽  
Millimeter Wave ◽  
Millimeter Waves ◽  
The Other ◽  
Radio Waves ◽  
Weather Phenomenon ◽  
Novel Method ◽  
And Diffusion

Terrestrial radio wave link faces various challenges like attenuation caused by gases, water vapor and other weather phenomenon like rain, storms, snow, fog, cloud etc. These challenges are responsible for absorption and diffusion of energy. Another kind of obstacles observed by the radio waves on terrestrial path is vegetation, lamppost, grills and other urban constructions. Different phenomenon is studied under these conditions like reflection, diffraction, refraction, scattering, depolarization etc. In case of millimeter waves various propagation studies has been performed under different scenarios. More propagation studies are needed to be done especially for fog. In this paper radio wave propagation studies are performed for fog using proposed fog model and results are compared with the other model proposed in the Literature. Another propagation study is performed for smoke which is unique of its kind. This study indicates that even smoke can causes attenuation for millimeter wave frequencies.

scholarly journals Modelling the influence of meteoric smoke particles on artificial heating in the D-region

2021 ◽  
Vol 39 (6) ◽  
pp. 1055-1068
Author(s):  
Margaretha Myrvang ◽  
Carsten Baumann ◽  
Ingrid Mann
Keyword(s):  
Electron Temperature ◽  
Radio Wave ◽  
Electron Density ◽  
Electron Attachment ◽  
Radio Waves ◽  
Night Time ◽  
Smoke Particles ◽  
D Region ◽  
Meteoric Smoke ◽  
Artificial Heating

Abstract. We investigate if the presence of meteoric smoke particles (MSPs) influences the electron temperature during artificial heating in the D-region. By transferring the energy of powerful high-frequency radio waves into thermal energy of electrons, artificial heating increases the electron temperature. Artificial heating depends on the height variation of electron density. The presence of MSPs can influence the electron density through charging of MSPs by electrons, which can reduce the number of free electrons and even result in height regions with strongly reduced electron density, so-called electron bite-outs. We simulate the influence of the artificial heating by calculating the intensity of the upward-propagating radio wave. The electron temperature at each height is derived from the balance of radio wave absorption and cooling through elastic and inelastic collisions with neutral species. The influence of MSPs is investigated by including results from a one-dimensional height-dependent ionospheric model that includes electrons, positively and negatively charged ions, neutral MSPs, singly positively and singly negatively charged MSPs, and photochemistry such as photoionization and photodetachment. We apply typical ionospheric conditions and find that MSPs can influence both the magnitude and the height profile of the heated electron temperature above 80 km; however, this depends on ionospheric conditions. During night, the presence of MSPs leads to more efficient heating and thus a higher electron temperature above altitudes of 80 km. We found differences of up to 1000 K in electron temperature for calculations with and without MSPs. When MSPs are present, the heated electron temperature decreases more slowly. The presence of MSPs does not much affect the heating below 80 km for night conditions. For day conditions, the difference between the heated electron temperature with MSPs and without MSPs is less than 25 K. We also investigate model runs using MSP number density profiles for autumn, summer and winter. The night-time electron temperature is expected to be 280 K hotter in autumn than during winter conditions, while the sunlit D-region is 8 K cooler for autumn MSP conditions than for the summer case, depending on altitude. Finally, an investigation of the electron attachment efficiency to MSPs shows a significant impact on the amount of chargeable dust and consequently on the electron temperature.

Propagation Model of Multi-hop High-frequency Radio in Ocean Signal Attenuation

2020 ◽  
Vol 34 (14) ◽  
pp. 2058019
Author(s):  
Wenbin Liu ◽  
Dongbing Liu
Keyword(s):  
Radio Wave ◽  
High Frequency ◽  
Ocean Model ◽  
Propagation Model ◽  
Radio Waves ◽  
Analysis Method ◽  
Signal Attenuation ◽  
Modeling And Analysis ◽  
Reflection Model ◽  
The Difference

On the basis of propagation the characteristics of Multi-hop High-Frequency Radio waves in Marine environment, the modeling and analysis method of ocean signal reflection model are firstly introduced from the attenuation of the radio wave. Then the difference between the influence of ocean and earth on wireless communication is studied. By studying the influence of ship on the loss of radio wave propagation, the original ocean model is improved. Finally, an ocean signal reflection model suitable for different marine environments is obtained.

scholarly journals Empirical Model of Radio Wave Propagation in the Presence of Vegetation inside Greenhouses Using Regularized Regressions

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6621
Author(s):  
Dora Cama-Pinto ◽  
Miguel Damas ◽  
Juan Antonio Holgado-Terriza ◽  
Francisco Manuel Arrabal-Campos ◽  
Francisco Gómez-Mula ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Radio Wave ◽  
Empirical Model ◽  
Precision Agriculture ◽  
Wave Attenuation ◽  
Multipath Propagation ◽  
Field Tests ◽  
Radio Wave Propagation ◽  
Radio Waves ◽  
Vegetation Height

Spain is Europe’s leading exporter of tomatoes harvested in greenhouses. The production of tomatoes should be kept and increased, supported by precision agriculture to meet food and commercial demand. The wireless sensor network (WSN) has demonstrated to be a tool to provide farmers with useful information on the state of their plantations due to its practical deployment. However, in order to measure its deployment within a crop, it is necessary to know the communication coverage of the nodes that make up the network. The multipath propagation of radio waves between the transceivers of the WSN nodes inside a greenhouse is degraded and attenuated by the intricate complex of stems, branches, leaf twigs, and fruits, all randomly oriented, that block the line of sight, consequently generating a signal power loss as the distance increases. Although the COST235 (European Cooperation in Science and Technology - COST), ITU-R (International Telecommunications Union—Radiocommunication Sector), FITU-R (Fitted ITU-R), and Weisbberger models provide an explanation of the radio wave propagation in the presence of vegetation in the 2.4 GHz ICM band, some significant discrepancies were found when they are applied to field tests with tomato greenhouses. In this paper, a novel method is proposed for determining an empirical model of radio wave attenuation for vegetation in the 2.4 GHz band, which includes the vegetation height as a parameter in addition to the distance between transceivers of WNS nodes. The empirical attenuation model was obtained applying regularized regressions with a multiparametric equation using experimental signal RSSI measurements achieved by our own RSSI measurement system for our field tests in four plantations. The evaluation parameters gave 0.948 for R2, 0.946 for R2 Adj considering 5th grade polynomial (20 parameters), and 0.942 for R2, and 0.940 for R2 Adj when a reduction of parameters was applied using the cross validation (15 parameters). These results verify the rationality and reliability of the empirical model. Finally, the model was validated considering experimental data from other plantations, reaching similar results to our proposed model.

scholarly journals Mapping the temperature-dependent and network site-specific onset of spectral diffusion at the surface of a water cluster cage

2020 ◽  
Vol 117 (42) ◽  
pp. 26047-26052
Author(s):  
Nan Yang ◽  
Sean C. Edington ◽  
Tae Hoon Choi ◽  
Elva V. Henderson ◽  
Joseph P. Heindel ◽  
...  
Keyword(s):  
Water Cluster ◽  
Ion Trap ◽  
Canonical Ensemble ◽  
Molecular Level ◽  
Magic Number ◽  
Spectral Diffusion ◽  
Water Molecules ◽  
Temperature Dependent ◽  
Cage Structure ◽  
Free Position

We explore the kinetic processes that sustain equilibrium in a microscopic, finite system. This is accomplished by monitoring the spontaneous, time-dependent frequency evolution (the frequency autocorrelation) of a single OH oscillator, embedded in a water cluster held in a temperature-controlled ion trap. The measurements are carried out by applying two-color, infrared-infrared photodissociation mass spectrometry to the D3O+·(HDO)(D2O)19isotopologue of the “magic number” protonated water cluster, H+·(H2O)21. The OH group can occupy any one of the five spectroscopically distinct sites in the distorted pentagonal dodecahedron cage structure. The OH frequency is observed to evolve over tens of milliseconds in the temperature range (90 to 120 K). Starting at 100 K, large “jumps” are observed between two OH frequencies separated by ∼300 cm−1, indicating migration of the OH group from the bound OH site at 3,350 cm−1to the free position at 3,686 cm−1. Increasing the temperature to 110 K leads to partial interconversion among many sites. All sites are observed to interconvert at 120 K such that the distribution of the unique OH group among them adopts the form one would expect for a canonical ensemble. The spectral dynamics displayed by the clusters thus offer an unprecedented view into the molecular-level processes that drive spectral diffusion in an extended network of water molecules.

Analisis Kinerja GSM-R Pada Kereta Cepat Indonesia

2020 ◽  
Vol 4 (2) ◽  
pp. 93-100
Author(s):  
Natriya Faisal
Keyword(s):  
New York ◽  
Control System ◽  
High Speed ◽  
Radio Waves ◽  
High Speed Train ◽  
New York University ◽  
Natural Conditions ◽  
Train Control ◽  
Train Control System ◽  
Railway System

The High-Speed Train of Indonesian will be implemented in 2022. The communication system used on the fast train is planned to use GSM-R in the future. GSM-R technology is expected to be applied to railways in Indonesia as well as in Europe. The railway system in Germany has applied GSM-R on the Berlin to Halle / Leipzig line using the first European Train Control System (ETCS) in Europe [2]. Radio waves used by GSM-R are at a frequency of 876 to 880 MHz for the uplink side and 921 to 925 MHz on the downlink side. This journal analyzes the GSM-R design that will be applied to Indonesian fast trains using the New York University Simulation (NYUSIM) method. This study evaluates the performance of GSM-R with intervention with natural conditions, such as temperature, humidity, air pressure, power and so on, resulting in a better GSM-R performance in terms of resistance to interference tested.

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