Direct Component Research Articles

Open Circuit Fault Detection of T-Type Grid Connected Inverters Using Fast S Transform and Random Forest.

To detect open circuit faults of grid-connected T-type inverters, this paper proposed a real-time method based on fast S transform and random forest. The three-phase fault currents of the inverter were used as the inputs of the new method and no additional sensors were needed. Some fault current harmonics and direct current components were selected as the fault features. Then, fast S transform was used to extract the features of fault currents, and random forest was used to recognize the features and the fault type, as well as locate the faulted switches. The simulation and experiments showed that the new method could detect open-circuit faults with low computation complexity and the detection accuracy was 100%. The real-time and accurate open circuit fault detection method was proven effective for grid-connected T-type inverter monitoring.

Impact of aerosol optics on vertical distribution of ozone in autumn over Yangtze River Delta

Abstract. Tropospheric ozone, an important secondary pollutant, is greatly impacted by aerosols within boundary layer (BL). Previous studies have mainly attributed ozone variation to either aerosol–BL or aerosol–photolysis interactions at the near-surface level. In this study, we analyze the sensitivities of ozone response to aerosol mixing states (e.g., mixing behavior hypothesis of scattering and absorbing components) in the vertical direction and address the effects of aerosol–BL and aerosol–photolysis interactions on ozone profiles in autumn by Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) simulations. The aerosol internal mixing state experiment reasonably reproduces the vertical distribution and time variation in meteorological elements and ozone. Sensitivity experiments show that aerosols lead to turbulent suppression, precursor accumulation, lower-level photolysis reduction, and upper-level photolysis enhancement. Consequently, ozone basically decreases within entire the BL during daytime (08:00–17:00 LT), and the decrease is the least in the external mixing state (2.0 %) when compared with internal (10.5 %) and core shell mixing states (8.6 %). The photolysis enhancement is the most significant in the external mixing state due to its strong scattering ability. By process analysis, lower-level ozone chemical loss is enhanced due to photolysis reduction and NOx accumulation under a volatile organic compound (VOC)-limited regime. Upper-level ozone chemical production is accelerated due to a higher photolysis rate resulting from aerosol backscattering. Therefore, the increased ozone entrainment from BL aloft to the surface induced by the boosted ozone vertical gradient outweighs the decreased ozone entrainment induced by turbulent suppression after 11:00 LT. Additional simulations support the finding that the aerosol effect on precursors, photolysis, and ozone is consistent under different underlying surface and pollution conditions.

Poiseuille and thermal transpiration flows of a dense gas between two parallel plates

The Poiseuille and thermal transpiration flows of a dense gas between two parallel plates are investigated on the basis of the Enskog kinetic equation under the diffuse reflection boundary condition. In contrast to the case of an ideal gas, the density and the gradients of pressure and the normal stress component in the flow direction are not uniform in the direction normal to the plates for a dense gas. The non-uniform normal stress gradient contributes also to the acceleration or deceleration of the thermal transpiration flow for small Knudsen numbers. The profiles of mass and heat flows as well as the net mass flows are obtained for various Knudsen numbers and ratios of the molecular diameter to the distance of plates. In the analysis of the Poiseuille flow, most characteristics of a force-driven flow with a small force are recovered. However, for the case of a dense gas, differences between the force-driven and the present pressure-driven flows are observed even within the linearized regime for small force and pressure gradient, especially at the microscopic level. The behaviour of the velocity distribution functions, in particular, the way in which they approach the ones for the Boltzmann equation as the molecular diameter becomes smaller, is clarified.

Radio Channel Measurements and Characterization in Substation Scenarios for Power Grid Internet of Things

Wireless communication technologies play a key role to support the implementation of power grid Internet of Things (PIoT). An in-depth knowledge of the radio channel is vital to the application of wireless communication technologies in PIoT. This paper investigates the radio channel measurements and characterization for PIoT substation scenarios. A novel channel sounder is designed for achieving omnidirectional measurements and phased array antennas based directional measurements, and a directional multipath components extraction algorithm is proposed. The channel sounding system is verified and is used to perform a series of 3.35 GHz omnidirectional and directional channel measurements in four substation scenarios, involving a 10 kV switch room, a 110 kV GIS room, a semi-indoor 110 kV substation and an outdoor 220 kV substation. Based on the measured channel impulse responses data, both large-scale and small-scale fading characteristics of substation channels are extracted and analyzed. Empirical models of path loss, shadow fading, Ricean K-factor and root-mean-square (RMS) delay spread are proposed. In addition, results of RMS angle spread of departure and RMS angle spread of arrival are presented. These results will provide useful reference for the deployment and optimization of wireless communication networks in PIoT substation scenarios.

On the Residual Finiteness of a Class of Polycyclic Groups II

Let A be a free abelian group of rank n (n ≥ 2) and ϕ be an automorphism of A, then $$A\langle \phi \rangle $$ is a polycyclic group. This paper investigates the residual finiteness of $$A\langle \phi \rangle $$ , and the special case that ϕ is a cyclic permutation of the direct components twisted by a rational integer m.

Analyzing Water Use Embodied in the Initial Construction and Life Cycle Management of Healthcare Facilities

Most research on the environmental sustainability of buildings often centers on reducing energy use and may overlook an equally crucial aspect of freshwater use. Buildings consume 1/5th of global fresh water in their construction as embodied water (EW) that must be reduced for long-term sustainability. Like embodied energy (EE), the EW of a facility is composed of a direct component used in construction processes and an indirect component that includes water used in manufacturing construction materials. An equally important component rarely covered in EW calculations is the energy-related embodied water (EREW), which comes from different energy sources that are consumed as EE, each of which depletes a significant amount of water in its generation, refinement, and transmission/transportation. This paper presents a macroeconomic model to compute and analyze not only the direct and indirect EW but also EREW of healthcare facilities. A wide variation is observed in calculated EW values associated with facilities’ initial construction (1,010-38,750 gallons/m²) and life cycle management (1,335-51,250 gallons/m²). The findings further show that EREW may represent 7.7% and 6% (average 6.7%) of the total EW of healthcare facilities relating to their initial construction and facilities management, respectively, including interior and exterior maintenance, repairs, and replacement activities. The significance of these findings is twofold. First, it shows that reducing EE may not help decrease most EW of a facility, and additional measures must be applied to decrease water use holistically. Second, it highlights the urgency of decreasing the water footprint of both renewable and non-renewable energy sources.

DIDACTIC TERMS OF USE OF BIOGRAPH INFINITI SPECIALIZED SOFTWARE IN UKRAINE’S HIGHER EDUCATION INSTITUTIONS

The article shows the possibility of using hardware ProComp Infiniti System with BioGraph Infiniti Software in the educational process of higher education institutions in Ukraine in different directions of training, including specific training conditions. The Infiniti system monitors and records a wide range of physiological and mechanical signals, analyzes and provides real-time biofeedback through various auditory and visual aids. The authors analyzed scientific and professional literature on the development and introduction of specialized software products in the educational process of higher education institutions in Ukraine and across the globe. The paper defines the advantages and prospects of carrying out a cycle laboratory work and research with BioGraph Infiniti tools and the principles of work with ProComp Infinity hardware. The didactic conditions of use of BioGraph Infiniti Software in the educational process of higher medical education institutions and universities of internal affairs of Ukraine are defined for formation of informational and subject competence of Ukraine’s students. Attention is focused on ensuring the flexibility of the educational process by means of variability, changes in the content and methods of education, forms of organization of educational classes with a direct practical component, a combination of different education methods for students of various types of higher education institutions. The possibilities of development of a series of laboratory works with their further placement in the virtual educational environment "Laboratory works system with specialized software Biograph Infiniti" are considered. Each laboratory work is created according to the principles of scientificity, integrity and professional orientation of education and includes 3 levels: general (basic), psychological and medical-biological.

Anisotropic Evolution of Effective Stress and Pore Pressure during Coalbed Methane Drainage

Summary The anisotropy and dynamic variation in permeability of gas-adsorbing coals have a significant influence on fluid flow behavior in the cleat system. The assumption of a constant anisotropy coefficient (the ratio between permeability components in orthogonal directions) has been traditionally made to simplify the seepage-stress coupling analytical model. In this approach, the pressure drop of the coalbed is separated into desorption and nondesorption areas. To evaluate the effective stress, pore pressure, permeability distribution, and variable anisotropy coefficient more accurately, analytical formulas were developed that consider elastic mechanics and methane sorption. The results show that the anisotropy coefficient can be dynamic when cleat compressibility anisotropy exists. Pressure contours are a set of ellipses that increase in eccentricity from the near-wellbore area to the pressure drop boundary, leading to corresponding anisotropy changes in effective stress and permeability. The gas desorption-related matrix shrinkage effect causes a discontinuous pressure drop gradient at the boundary between desorption and nondesorption areas, resulting in nonsmooth pressure drop curves. The pressure gradient difference changes with the radius of the desorption area and is nonisotropic, with the high-permeability direction showing a greater difference than the low-permeability direction. These results indicate that the dynamic anisotropy coefficient has a significant impact on coalbed drainage and extraction. Compared to previous mathematical models, which assumed permeability isotropy or constant anisotropy coefficient in cleat systems, the proposed model provides a more accurate method to evaluate pressure and permeability distribution.

A new scheme for adding a pilot at direct current component location in photonics-assisted OFDM MMW system

This paper proposes a new scheme, that is, a constant is added to the real part or imaginary part of the signal at the transmitting end, and the constant becomes a pilot at the location of DC component, thereby replacing the scheme of traditional manual bias IQ modulator to generate a pilot. By adopting this scheme, the purpose of frequency offset estimation can be achieved, and the performance can be improved by quantitatively optimizing the magnitude of the constant at the same time. Using this technology and combined probability shaping technology, a 3.4Gbaud 256QAM OFDM signal can be transmitted 700 m wireless distance, achieving the normalized general mutual information (NGMI) threshold of 0.83 with 25% soft-decision forward-error correction (SD-FEC) overhead.

PIFs interact with SWI2/SNF2-related 1 complex subunit 6 to regulate H2A.Z deposition and photomorphogenesis in Arabidopsis

Light is an essential environmental signal perceived by a broad range of photoreceptors in plants. Among them, the red/far-red light receptor phytochromes function to promote photomorphogenesis, which is critical to the survival of seedlings after seeds germination. The basic-helix-loop-helix transcription factors phytochrome-interacting factors (PIFs) are the pivotal direct downstream components of phytochromes. H2A.Z is a highly conserved histone variant regulating gene transcription, and its incorporation into nucleosomes is catalyzed by SWI2/SNF2-related 1 complex, in which SWI2/SNF2-related 1 complex subunit 6 (SWC6) and actin-related protein 6 (ARP6) serve as core subunits. Here, we show that PIFs physically interact with SWC6 in vitro and in vivo, leading to the disassociation of HY5 from SWC6. SWC6 and ARP6 regulate hypocotyl elongation partly through PIFs in red light. PIFs and SWC6 coregulate the expression of auxin-responsive genes such as IAA6, IAA19, IAA20, and IAA29 and repress H2A.Z deposition at IAA6 and IAA19 in red light. Based on previous studies and our findings, we propose that PIFs inhibit photomorphogenesis, at least in part, through repression of H2A.Z deposition at auxin-responsive genes mediated by the interactions of PIFs with SWC6 and promotion of their expression in red light.

Impact of Direct Taxation on Economic Growth: Empirical Evidence Based on Panel Data Regression Analysis at the Level of Eu Countries

Through fiscal policy, the government can influence businesses and individuals in order to regulate their behaviour. The research used panel data from all 27 EU countries covering the period 2008–2020 to investigate the impact of direct taxation on economic growth at the level of two main clusters of countries concerning fiscal efficiency. Therefore, the analysis employed cluster methods to classify the main EU countries in both groups of countries with a high level of fiscal efficiency and those with a rather limited level of fiscal efficiency. The study employs fixed effect models and dynamic GMM methods to investigate the effect of direct taxation components (personal and corporate income taxes) on economic growth. The analysis also considers the informal economy’s role in relation to the official economy. The empirical results revealed that corporate income taxes significantly negatively impact economic growth for both clusters of high- and limited fiscal efficiency countries. Additionally, personal income tax was associated with lower economic growth for countries in the limited fiscal efficiency group. Thus, from the perspective of policymakers, lowering direct taxation can increase disposable income, stimulate consumption and economic growth, encourage investment leading to job creation, increase competitiveness, and reduce tax evasion and avoidance, thereby leading to a more efficient tax system.

Experimental performance analysis of a mixed forced convection solar dryer: Application to cocoa bean drying

The influence of a mixed forced convection solar dryer with thermal storage, on the quality of cocoa beans is studied. This study has as reference the quality level recommended by the international standard ISO 2451. A collection of experimental data with the realized dryer was made for six days on a sample of 10 kg of cocoa coming from the cocoa zone of Kekem in Cameroon. This sample consisted of more than 300 cocoa beans as recommended by the standard for testing. The dryer, is mainly made of wood for the frame and polystyrene for the isolating part, it has an operation based on a combination of the direct and indirect model. A control and measuring device for airflow, temperature and humidity has been installed in the drying chamber. The dryer's direct solar component can be used to accelerate the drying process, especially during the first drying phase. This experimental system was able to dehydrate cocoa beans in 2 days with a water content that went from 53.4 % to 4.6 %. From the beginning to the end of the drying process, the temperature and the relative humidity were respectively between 18 and 55 °C and between 28 and 80 %. Placing the same amount of beans in the acceleration chamber, the drying chamber and in the open air, for an amount of water to be removed of about 5.07 kg, the water removal rates were respectively about 0.32 kg/h, 0.21 kg/h and 0.10 kg/h for an effective daily average of 8 h. The drying performances of the acceleration chamber and the drying chamber are respectively 68 % and 52 %, more than the open-air drying.

Collision-energy dependence of the Breit-Wheeler process in heavy-ion collisions and its application to nuclear charge radius measurements

The collision energy dependence of the cross section and the transverse momentum distribution of dielectrons from the Breit-Wheeler process in heavy-ion collisions are computed in the lowest-order QED and found to be sensitive to the nuclear charge distribution and the infrared divergence of the ultra-Lorentz-boosted Coulomb field. Within a given experimental kinematic acceptance, the cross section is found to increase while the pair transverse momentum ($\sqrt{\ensuremath{\langle}{p}_{T}^{2}\ensuremath{\rangle}}$) decreases with increasing beam energy. We demonstrate that the transverse-momentum component of Weizs\"acker-Williams photons is due to the finite extent of the charge source and electric field component in the longitudinal direction. We further clarify the connection between the nuclear charge distribution and the kinematics of produced ${e}^{+}{e}^{\ensuremath{-}}$ from the Breit-Wheeler process, and propose a criterion for the validity of the Breit-Wheeler process in relativistic heavy-ion collisions. Following this approach we demonstrate that the experimental measurements of the Breit-Wheeler process in ultrarelativistic heavy-ion collisions can be used to quantitatively constrain the nuclear charge radius. The extracted parameters show sensitivity to the impact parameter dependence, and can be used to study the initial-state and final-state effects in hadronic interactions.

Further validation of the estimates of the downwelling solar radiation at ground level in cloud-free conditions provided by the McClear service: the case of Sub-Saharan Africa and the Maldives Archipelago

Abstract. Being part of the Copernicus Atmosphere Monitoring Service (CAMS), the McClear service provides estimates of the downwelling shortwave irradiance and its direct and diffuse components received at ground level in cloud-free conditions, with inputs on ozone, water vapor and aerosol properties from CAMS. McClear estimates have been validated over several parts of the world by various authors. This article makes a step forward by comparing McClear estimates to measurements performed at 44 ground-based stations located in Sub-Saharan Africa and the Maldives Archipelago in the Indian Ocean. The global irradiance received on a horizontal surface (G) and its direct component received at normal incidence (BN) provided by the McClear-v3 service were compared to 1 min measurements made in cloud-free conditions at the stations. The correlation coefficient is greater than 0.96 for G, whereas it is greater than 0.70 at all stations but five for BN. The mean of G is accurately estimated at stations located in arid climates (BSh, BWh, BSk, BWk) and temperate climates without a dry season and a hot or warm summer (Cfa, Cfb) or with a dry and hot summer (Csa) with a relative bias in the range [−1.5, 1.5] % with respect to the means of the measurements at each station. It is underestimated in tropical climates of monsoon type (Am) and overestimated in tropical climates of savannah type (Aw) and temperate climates with a dry winter and hot (Cwa) or warm (Cwb) summer. The McClear service tends to overestimate the mean of BN. The standard deviation of errors for G ranges between 13 W m−2 (1.3 %) and 31 W m−2 (3.7 %) and that for BN ranges between 31 W m−2 (3.0 %), and 70 W m−2 (7.9 %). Both offer small variations in time and space. A review of previous works reveals no significant difference between their results and ours. This work establishes a general overview of the performances of the McClear service.

Phase separation strategy achieves printable corrosion-resistant ternary SiOC supercapacitors with sustained capacitance increase

Carbon-ceramic material with well-designed components and architectures is an effective strategy to fulfill the chemical-stability requirements of long-life supercapacitors. Herein, we proposed a direct cation-induced component recombination strategy to convert the intrinsically insulated SiOC ceramic to an electrochemically active ternary state for stable and long-life capacitive energy storage. Meanwhile, the cation-induced component recombination process can be directly coupled to advanced photocurable 3D printing technology to create the integral ternary SiOC electrode with various 3D structures for a complex-shaped supercapacitor. As a result, the ternary SiOC electrodes with four-type triply periodic minimal surface structures have been successfully printed and used in an alkaline supercapacitor with high corrosivity. The integral ternary SiOC electrode with Diamond structure demonstrates high capacity (756 mF·g−1 at 1.7 mA·g−1). The symmetrical supercapacitor based on ternary SiOC electrodes with a Diamond structure exhibits outstanding long-term durability (181.5 % capacity retention after 10,000 cycles) in highly corrosive environments. In addition, the ternary SiOC electrode also shows extremely high cycling stability in highly corrosive seawater, with a capacity retention rate of over 95 % after 20,000 cycles. Therefore, this novel 3D-printed ternary SiOC electrodes provides an efficient approach for developing long-term stable and reliable supercapacitors for applications in highly corrosive environments.

Managing the coagulopathy of postpartum hemorrhage: an evolving role for viscoelastic hemostatic assays

Postpartum hemorrhage (PPH) is usually caused by obstetrical complications but may be exacerbated by hemostatic impairment. Standard laboratory tests of coagulation often take too long to become available to inform treatment in a rapidly changing clinical situation. The role of point-of-care viscoelastic hemostatic assays (VHAs) in monitoring hemostatic impairment and guiding procoagulant blood product replacement during PPH is evolving, although these technologies are not available in most maternity units. We have used VHAs during PPH in our institution for the last 8 years and have developed a simple algorithm to direct blood component replacement. VHAs are useful for reassuring clinicians that hemostasis is adequate and that procoagulant blood products are not required and an obstetrical cause for bleeding needs to be sought. VHAs can be used to detect hypofibrinogenemia due to dilution or acute obstetrical coagulopathy and to guide fibrinogen replacement. The role of VHAs in guiding fresh frozen plasma infusion is less clear, but normal results suggest that fresh frozen plasma is not required. In this review, we describe 3 cases of postpartum hemorrhage to illustrate different hemostatic scenarios and discuss the controversies and evidence gaps related to each case.

Feasibility of imaging under structured illumination for evaluation of white striping in broiler breast fillets

Muscle myopathies or defects, such as white striping (WS), downgrade the quality of broiler meat, leading to the loss of millions of dollars annually for the U.S. poultry industry. Visual inspection is currently practiced for assessing myopathies in broiler meat, which is however prone to human evaluation error, labor-intensive, and costly. Imaging under uniform or diffuse illumination has been investigated for assessing broiler meat quality, but their performance is not always satisfactory, especially for detecting subtle defects with few visual symptoms. This study presents the first proof-of-concept evaluation of the utility of an innovative technique for improved imaging of structures of biological materials, i.e., structured-illumination reflectance imaging (SIRI), for detecting WS conditions in broiler breast meat. Broiler breast fillets with varying degrees of WS severity were imaged by an in-house assembled SIRI system under sinusoidal illumination at different spatial frequencies (0.05–0.40 cycles/mm). The acquired pattern images were demodulated into direct components (DC) and amplitude components (AC) at each spatial frequency. Texture features were extracted from DC and AC images for building classification models using regularized linear discriminant analysis, which were to classify meat samples into 2, 3, and 4 classes, respectively, according to WS conditions. AC images were found by visual inspection more effective than DC in resolving WS characteristics, depending on the spatial frequency of illumination patterns. Compared to DC, AC yielded the maximum accuracy improvements of 8.33%, 7.93%, and 12.3% in 2-, 3- and 4-class classifications, respectively. Models using ranked features yielded similar improvements of up to 9.53% by AC over DC. The SIRI technique is promising for enhanced detection of WS and potentially other defects of broiler breast meat. • Structured-illumination reflectance imaging (SIRI) was used for poultry quality detection. • Amplitude component (AC) images enabled resolving white striping (WS) of broiler breast meat. • Broiler breast fillets were classified by models into 2, 3 and 4 classes according to WS conditions. • SIRI offered substantial improvements of up to 12% in classifying WS-affected poultry samples.

Radon mapping, correlation study of radium, seasonal indoor radon and radon exhalation levels in communities around Ghana atomic energy commission

Radon mapping and seasonal radon studies have been carried out within the communities around the Ghana Atomic Energy Commission (GAEC), using ArcMap geostatistical interpolation tool. The correlation analysis was done using Pearson's correlation tools. Average seasonal indoor radon variations for CR (rainy) and CD (dry) with mean values ranging from 28.9 to 177.2 Bq/m3 (78.1 ± 38.7 Bq/m3) and 24.4–125.5 Bq/m3 (69.9 ± 24.2 Bq/m3). Average seasonal soil radon exhalation for ER (rainy) and ED (dry) with mean values ranging from 39.6 to 100.3 (68.9 ± 24.2 μBq/m2 h) and 55.2 to 111.9 (77.1 ± 18.7 μBq/m2 h). Radium concentrations ranged from 8.1 to 42.2 Bq/kg (21.3 ± 9.9 Bq/kg). Annual effective dose and resultant effective dose to lungs were found to be 0.9 to 2.9 (1.9 ± 0.8 mSv/yr), 2.1 to 9.2 (4.6 mSv/yr). The study recorded the highest and lowest positive correlation coefficient was found in the study with higher and lower coefficient values of 0.81 and 0.47 recorded in radium concentration with radon exhalation and indoor radon concentration within the dry season respectively. Pearson correlation result recorded values 0.81 and 0.47 as the highest and lowest positive coefficient values for the radium concentration correlation between radon exhalation and indoor radon concentration. One directional principal component was observed in radium concentration, seasonal radon exhalation, and indoor radon concentration. Two clusters originated from radium and seasonal radon concentrations present in dwellings as well as soils. Pearson's correlation results were in agreed with the principal component and cluster factor analysis. The study obtained the highest and lowest indoor radon concentrations with radon exhalation in rainy and dry seasons. Radium concentration was found to have a considerable effect on indoor radon and radon exhalation in dwellings and soils.

Using sensorless direct torque with fuzzy proportional-integral controller to control three phase induction motor

Induction motors (IM) attracted many researchers in the last few decades. In this field, various applications are implemented, such as servo motor drives and electric vehicles. This work applies a sensorless direct torque controller (DTC) to control a three-phase IM. System dynamics of the IM were derived. A nonlinear dynamic model had introduced with white noise. Given the complexity of the dynamics, the Jacobean Linearization technique has been used to obtain the linear model for a control task. A DTC technique is employed to control the motor speed of the system with a combination of two controllers. The fuzzy proportional-integral (PI) controllers are applied to obtain the reference torque based on an optimization process against the speed error raise. The optimizer is called grey wolf optimizer (GWO) and is implemented to achieve the centre values of the two output memberships for the fuzzy PI controllers. Then the extended Kalman filter (EKF) is used to evaluate the direct and quadratic components of the rotor flux and rotor speed from the observation of stator voltages and currents. The system is tested employing MATLAB simulation software and determines the targeted results. The outcomes are evaluated to improve the control performance.

Effects of Fire Plumes From Pine Needles on Small-Scale Fading in Radiowave Propagation

In this article, radiowave fading caused by fire plumes due to the burning of heaps of pine needles is studied. Detailed characterization of the fire impact in terms of excess loss due to the yielded plumes at UHF frequencies, mainly in the L-band, when considering two different ignition sources, is also presented. The implemented small-scale fire scenario is composed of a 1 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times 1$ </tex-math></inline-formula> m metallic grid covered with a 0.6 kg pine needle fuel bed that was placed right above a circular and linear gas burner to mimic an underbrush scenario. The propagation phenomena were evaluated through specific wideband measurements as the fire developed while intersecting the radio path at the antennas’ boresight. Results demonstrate changes in the propagation medium that is strongly influenced by the plume, which ultimately becomes (partly) ionized. Deep fades of up to 12 dB below median levels at specific frequencies during a short period of time, when the fire is more intense, were measured. We also obtained an overall median excess loss due to fire of up to 2 dB in the frequency range from 0.6 to 2 GHz in a relatively short path (below 1 m). A time-domain analysis allowed us to expand these results yielding fading values of the direct component of more than 3 dB in the presence of fire. Extending the findings presented in this article to a real-scale fire scenario, in which median excess loss of more than 20 dB and deeper nulls are ought to be expected, sets the rationale and motivation to pursue future work on the topic, with practical relevance to future mission-critical communication networks planning, such as, but not limited to, LTE Public-Safety and specific 5G use cases.