Temperature Dependence Of Loss Research Articles

Microstructural, magnetic and electric properties of sol-gel synthesized Na0.5Bi0.5TiO3–CoFe2O4 composites

In this work, we presented investigations on the microstructural, magnetic, dielectric and conductive properties of (1-x)Na0.5Bi0.5TiO3-xCoFe2O4 (NBT-CFO) composite ceramics (x = 0.1, 0.2, 0.3 and 0.5). The composites were synthesized using the in-situ sol-gel method, and the resulting CFO/NBT embedded structure was observed in the 0.9NBT–0.1CFO sample. Rietveld refinement confirmed that the embedded structure had remarkable effects on the c/a ratios of NBT-CFO composites. Increasing normalization saturation magnetizations were observed with increasing of CFO contents, thus revealing the influence of phase interfaces on magnetism. Dielectric relaxation anomalies were observed on both temperature dependent permittivity and loss spectra. Two sets of anomalies in these spectra were caused by space charges on the phase interfaces of embedded CFO grains and the NBT matrix. The conduction behavior of ceramics with and without the embedded structure obeyed the double power law and Jonscher's fraction power law, respectively, which inferred a transformation from the AC to the DC conduction mechanism with the disappearance of the embedded structure.

Customized unique core-shell Fe2N@N-doped carbon with tunable void space for microwave response

Here, we report a unique core-shell nanocomposite of Fe2N@N-doped carbon that coats dopamine-derived carbon shells on porous Fe2N nanoparticles via a facile and effective soft chemical method. The feasibility of preparing core-shell structure in the process of polymerization is realized by utilizing the fact that affluent amino and hydroxyl groups in dopamine endow the formidable chelation ability with metal ions. Temperature-dependent volume shrinkage effect of Fe2N originates from the lattice transformation in nitridation process, which is the key factor to control the void space inside carbon nanocubes and optimize the electromagnetic performance. Consequently, the as-prepared samples achieve excellent reflection loss (RL) values and effective absorption bandwidth at an even thin thickness of 1.4 mm. The balance between the temperature-dependent conduction loss and the optimization of hole structure impedance matching may be responsible for the excellent microwave behaviors. This work offers an attractive core-shell Fe2N@carbon with controllable void space as a promising candidate to handle the electromagnetic interface (EMI) issues.

Bicomponent poly(ethylene)/poly(propylene) fiber bonding using dielectric inks

A dielectric ink thermal processing method has been developed to bond bicomponent poly(ethylene)/poly(propylene) (bico-PE/PP) fibers that are commonly used to make nonwoven fabrics for a variety of applications including medical, hygiene, and filtration needs. Dielectric inks applied to the fibers offer a number of potential advantages over conventional calendar bonding including more efficient energy conversion, faster heating rates, heating directed to desired bond sites, facile patterning, the ability to function on materials with substantial amounts of loft, and avoidance of fiber damage induced by calendar roller contact. Poly(ethylene) and poly(propylene) do not efficiently convert microwave energy to heat on their own; therefore, propylene carbonate (PC) and glycerine carbonate (GC) were selected as ink candidates due to their large dipole moments and dielectric constants. The temperature-dependent dielectric constant and dielectric loss values of both carbonates were measured as well as their thermal responses to microwave energy at 2.45 GHz. The dispersion of each carbonate on bico-PE/PP fibers, including the application to nonwoven fabrics, was characterized by optical microscopy. The thermal response for ink loading as a function of microwave radiation exposure time was investigated. Tensile test results showed that the bonding strength of dielectric ink bonded samples was comparable with the bonding obtained using conventional calendar bonding. The results presented herein demonstrate that dielectric inks provide fast heating rates, excellent fiber bonding, and the ability for facile nonwoven patterning.

Digital twins probe into food cooling and biochemical quality changes for reducing losses in refrigerated supply chains

Refrigerated transport and storage of mango fruit are essential to maintain quality, reduce food waste and the associated embodied energy losses. Refrigeration is also key to enable successful transcontinental export to distant markets. To minimize the environmental impact of the cold chain and to optimize logistics, a better knowledge of the fruit quality evolution within individual shipments would be extremely valueable. For this purpose, a digital fruit twin is developed, based on mechanistic modeling. This digital twin simulates the thermal behavior of mango fruit throughout the cold chain, based on the measured environmental temperature conditions, namely the air temperature in the vicinity of the fruit. At the same time, the evolution of associated quality attributes, due to enzymatically-driven, temperature-dependent biochemical degradation reactions, is quantified. Also, a biophysical counterpart of real mango fruit – an innovative fruit simulator sensing device – was developed and used for model validation of fruit pulp temperatures. We identified – in-silico – the impact of the unique delivery air temperature history and cold chain length on fruit quality evolution for actual maritime vs. airfreight transport pathways. Digital twins were found to provide complementary insights in the thermophysical behavior of fruit, particularly in supply chains of very perishable species, and for storage at low airflow rates. Such mechanistic modeling enabled to understand, record, and predict where temperature-dependent fruit quality loss occurs in each supply chain. In that way, digital twins can help to improve refrigeration processes and logistics to reduce food losses, thereby making the refrigerated supply chain greener.

Frequency dependence of ac losses in a granular superconductor Lu2Fe3Si5

By using ac susceptibility measurements, the frequency dependence of ac losses was experimentally studied in a granular Lu2Fe3Si5 sample. Three types of temperature dependent ac loss peaks were observed which were attributed to the intergranular, intragranular and intrinsic bulk behaviors. It is found that the intergranular and intragranular peaks show clear frequency dependence while the intrinsic peak remains constant as the frequency changes. With increasing frequency the pinning difference between the intergranular and intragranular becomes small, and vanishes at high frequencies. The vortex glass temperature Tg was determined to be 5.97 K. The phase diagram was constructed by measuring the ac susceptibility under different magnetic fields.

Dielectric, magnetic hyperthermia, and photocatalytic properties of ZnFe2O4 nanoparticles synthesized by solvothermal reflux method

Spinel ferrites at nanoscale showed quite different properties rather than the bulk counterpart. Among all the ferrites, ZnFe2O4 compound is chemically stable and showed very good properties at room temperature. In this investigation, we reported the synthesis and characterization of ZnFe2O4 single-phase crystals of diameter 11 nm by solvothermal reflux method. Temperature-dependent dielectric constant, dielectric loss, and ac-electrical conductivity of the pellet were measured up to 450 °C under different alternating electric field frequencies from 1 kHz to 1 MHz. The obtained data revealed interfacial or space charge polarization mechanism. Furthermore, the sample showed superparamagnetic nature at room temperature. In addition, the magnetic hyperthermia value and specific heat generation rate (SHGR) of 128.76 J s−1 g−1 for ZnFe2O4 compound at 1 mg mL−1 concentration were evaluated. The data were interpreted by spin-relaxation mechanism. ZnFe2O4 nanoparticles showed good photocatalytic activity under UV light irradiation. The data were interpreted by electron–hole pair and radical formation and degradation of Rhodamine B dye.

Measurement of specific heat capacity via fast scanning calorimetry—Accuracy and loss corrections

This study explores specific heat capacity (cp) measurements via fast scanning calorimetry, with a focus on correcting measured heat flow by accounting for temperature dependent heat losses. Using MultiSTAR-UFS1 sensors with the Mettler-Toledo Flash-DSC 2+, cp of Pb (99.998% purity) was measured in dependence of the sample mass and scanning rate. Masses from 0.3–5 μg were evaluated at rates of 100, 1000 and 2000 K s−1 in the temperature range −20 to 320 °C. Two correction methods are shown and compared to cp results without corrections. Heat loss corrections are mandatory when measuring cp, but are in particular important for low masses and rates. High consistency was found between the two proposed correction procedures giving good confidence in their viability. A slight but consistent overestimation of cp compared to literature casts uncertainty upon the determined sample mass. Whilst the systems under study in this work encompass only pure Pb, the arguments and procedures of the shown method of cp determination are applicable to any system in the absence of physical transformations.

Investigation of Structural, Electrical and Thermal Characteristics of NdFeO3 Ceramic

The synthesis of single phase polycrystalline ceramic sample of NdFeO₃ by high temperature solid state reaction technique using high purity oxides has been reported. The structural parameters were investigated by Rietveld refinement program. The prepared ceramics show orthorhombic structure with space group Pnma. The frequency and temperature dependent dielectric constant, dielectric loss and ac conductivity of the compound have been studied. The dc conductivity has also been measured and its activation energies were calculated using Arrhenius relation. The calculated heat capacity (ΔCp) and enthalpy change (ΔH) of the compound are 0.068 J/gK and 2.3664 J/g respectively.<div><br></div>

An investigation on curing rheokinetics of a nadic end-capped MDA-BTDA-ODA copolyimide resin by dynamic mechanical analysis

Abstract The curing behavior of a nadic end capped MDA-BTDA-ODA copolyimide resin was investigated using dynamic mechanical analysis in the shear mode. The studied copolyimide consists of 3,3′,4,4′-benzophenonetetracarboxylic acid dianhydride (BTDA) with a 50:50 M combination of 4,4′-diaminodiphenylmethane (MDA) and 3,4′-oxydianiline (ODA) monomers. The effects of curing temperature and time on the rheological properties of the resin were examined. At the beginning of the network formation process, an increase in the storage modulus, loss modulus and complex viscosity was observed. The gelation temperature, Tgel, was determined from the intersection points of the temperature-dependent storage and loss moduli curves. It was found that the rate of gelation of the resin was increased with increasing temperature. In terms of mechanical curing condition, the kinetics of isothermal network formation process at different isothermal curing temperatures were monitored by using Kamal-Sourour model. The model fitted well with experimental data. Therefore, mechanical conversion at different temperatures can be well predicted by the kinetics data.

Hierarchical Sm-doped ZnO nanorod–nanosheet architecture: dielectric and ferroelectric studies

A novel hierarchical samarium (Sm)-doped ZnO nanorod–nanosheet architecture with high-temperature ferroelectricity (Tc ~ 110 °C, Ec ~ 3.64 kV/cm and Pr ~ 0.08 μC/cm2) have been developed here using wet chemical co-precipitation method. In this study, we show the origin of ferroelectric behavior in Sm-doped ZnO product and study the effect of frequency and temperature on its dielectric characteristics. Interestingly as an impact of Sm-doping, the morphology of pristine ZnO got evolved from 1D nanopencils (NPCs) to 3D hierarchical architectures composed of both 1D nanorods (NRs) and 2D nanosheets (NSs). Crystallite size (L), lattice strain (e), deformation stress (σ), and uniform energy density (u) of both isolated 1D NPCs and 3D hierarchical NR–NS architectures were evaluated using the Debye–Scherrer and Williamson–Hall methods. Temperature-dependent real dielectric constant (e′) revealed a ferro- to para-electric transition peak at 110 °C. Temperature-dependent complex dielectric constant (e″), dielectric loss (tan δ) and ac conductivity (σ) were found to increase with temperature. The frequency-dependent dispersion curves of dielectric properties showed an increase in ac conductivity with increase in frequency whereas complex part of dielectric constant and dielectric loss showed an opposite trend. The Sm-doped ZnO NR–NS architecture exhibits weak ferroelectricity with a coercive field (Ec) of 3.64 kV/cm and a remnant polarization (Pr) of 0.08 μC/cm2 at room temperature. Moreover, the high-temperature ferroelectricity established in this work will make Sm–ZnO a futuristic material in the field of designing memory devices.

Quantifying Temperature-Dependent Substrate Loss in GaN-on-Si RF Technology

Intrinsic limits to temperature-dependent substrate loss for GaN-on-Si technology, due to the change in resistivity of the substrate with temperature, are evaluated using an experimentally validated device simulation framework. Effect of room temperature substrate resistivity on temperature-dependent coplanar waveguide (CPW) line loss at various operating frequency bands is then presented. CPW lines for GaN-on-high-resistivity Si are shown to have a pronounced temperature dependence for temperatures above 150 °C and have lower substrate losses for frequencies above the X-band. On the other hand, GaN-on-low-resistivity Si is shown to be more temperature insensitive and has lower substrate losses than even highly resistive Si for lower operating frequencies. The effect of various CPW geometries on substrate loss is also presented to generalize the discussion. These results are expected to act as a benchmark for temperature-dependent substrate loss in GaN-on-Si RF technology.

Electrical properties and relaxor phase evolution of Nb-Modified Bi0.5Na0.5TiO3-Bi0.5K0.5TiO3-SrTiO3 lead-free ceramics

In this work, the crystalline phase, domain structure, and electrical properties of [Bi0.5(Na0.84K0.16)0.5]0.96Sr0.04Ti1-xNbxO3 (x = 0.010–0.030) ceramics are investigated. Increasing the Nb content induces the phase transition from coexistent rhombohedral and tetragonal phases to a single pseudo-cubic phase, and the lamellar ferroelectric domains evolve into polar nanoregions. Decreased ferroelectric-to-relaxor transition temperature and enhanced frequency dispersion are found in the temperature-dependent dielectric constant and loss, implying a transition from the non-ergodic to ergodic relaxor state. The Nb substitution significantly degrades the long-range ferroelectric order with sharply decreased piezoelectric coefficients from ˜ 140 to ˜ 1 pC/N. However, a large strain of 0.32% at 5 kV/mm (normalized strain of 640 pm/V) is obtained around the critical composition of x = 0.0225. The composition of x = 0.030 shows good temperature insensitivity of the strain response, characterized by 308 pm/V with less than 15% reduction from 25 °C to 125 °C.

Significance of oxygen defects in SnO2 quantum dots as hybrid electrochemical capacitors

Understanding the role of defects is important due to its influence on electrical and optical properties of SnO2. This study reports the role of oxygen defects in SnO2 quantum dots decorated in carbon paper for an improved electron transfer process in electrochemical applications. A simple and cost-effective chemical route for preparation of a SnO2-decorated carbon paper electrode is described. The pseudo-capacitance property of SnO2nano-materials allowed strong improvement in capacitance value compared to pristine carbon paper. Transmission electron microscopy, Raman and photoluminescence studies reveal the presence of ultra-small SnO2 nanoparticles with defects related to prevalent oxygen vacancies. Electron paramagnetic resonance measurement indicates presence of singly charged defect in diamagnetic SnO2. Temperature-dependent photoluminescence, vibrational studies and electron energy loss spectroscopy provide further evidence for shallow in-plane oxygen defects in the SnO2 quantum dots, while impedance measurement discloses their significance in the electrochemical hybrid structure.

Electromagnetic heating control via high-frequencyresonance of a triple-layer laminate

Beamed energy transport requires the use of heat exchangers to collect the thermal energy produced from the absorption of electromagnetic radiation. To explore the high-frequency effects of wave–geometry interactions on this heat transfer, we consider a central dielectric layer, possessing a temperature-dependent loss factor, surrounded by two fluid channels filled with a lossless dielectric fluid. Considering an asymptotically thin domain, we derive a diffusion–reaction equation, assuming no flow in the fluid. We show that the high-frequency effects generate a new energy balance leading to a previously unknown steady-state solution. A characterization of the steady-state-dependent parameters is performed in an effort to determine a mechanism to control the nonlinear heating. Diffusive effects are shown to produce regions of the power response where steady-state solutions are replaced by traveling-wave solutions. These regions are also location to the greatest heating efficiency. Analytical approximations to the wave speed and location of these regions are found using boundary layer theory.

Effects of Nd-doping on multiferroic properties of Bi&lt;sub&gt;6−x&lt;/sub&gt;Nd&lt;sub&gt;x&lt;/sub&gt;Fe&lt;sub&gt;1.4&lt;/sub&gt;Ni&lt;sub&gt;0.6&lt;/sub&gt;Ti&lt;sub&gt;3&lt;/sub&gt;O&lt;sub&gt;18&lt;/sub&gt; polycrystalline

Single phase polycrystalline Nd-modified BNFNT-&lt;i&gt;x&lt;/i&gt; series samples are obtained from the precursors of the same chemical formula, and prepared by using the citric acid-nitrate method. The X-ray photoelectron spectroscopy measurement indicates that a slight Nd modification does not exert significant influence on the stability of the octahedral FeO&lt;sub&gt;6&lt;/sub&gt;, nor NiO&lt;sub&gt;6&lt;/sub&gt; nor TiO&lt;sub&gt;6&lt;/sub&gt;. When the molar concentration of Nd exceeds 0.25, the stability of BiO layer is cemented and conducive to the insulating role of BiO layer. It is seen that a small quantity of Nd substitution for bismuth can improve the ferroelectric polarization (2&lt;i&gt;P&lt;/i&gt;&lt;sub&gt;r&lt;/sub&gt;) of ～ 19.7 &lt;inline-formula&gt;&lt;tex-math id="Z-20190127014418-3"&gt;\begin{document}$ \mu {\rm C/cm }^2$\end{document}&lt;/tex-math&gt;&lt;alternatives&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="3-20181287-e-lijj-revised_Z-20190127014418-3.jpg"/&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="3-20181287-e-lijj-revised_Z-20190127014418-3.png"/&gt;&lt;/alternatives&gt;&lt;/inline-formula&gt;. The room-temperature magnetization (2&lt;i&gt;M&lt;/i&gt;&lt;sub&gt;s&lt;/sub&gt;) can reach a maximal value of ～ 4.132 emu/g (1 emu/g = 10&lt;sup&gt;−3&lt;/sup&gt; A·m&lt;sup&gt;2&lt;/sup&gt;/g)in the BNFNT-0.20 sample. Two anomalies are observed in the temperature-dependent dielectric loss spectrum: one is situated in the temperature range from 200 K to 400 K and the other is located in the vicinity of 900 K. It is considered that the loss anomaly found near 900 K might be associated with the viscous motion of ferroelectric domain walls. In addition, the loss peak shown in a temperature range from 200 K to 400 K shifts toward the higher temperature with measuring frequency increasing, indicating the characteristics of dielectric relaxor behavior. The activation energy is evaluated to be 0.287−0.366 eV, which suggests that the relaxor is associated with the electrons transfer and hop between Fe&lt;sup&gt;3+&lt;/sup&gt; and Fe&lt;sup&gt;2+&lt;/sup&gt;. The room-temperature magnetization (2&lt;i&gt;M&lt;/i&gt;&lt;sub&gt;s&lt;/sub&gt;) has reached a maximal value of ～ 4.132 emu/g in the BNFNT-0.20 sample. The lattice distortion due to the introduction of Nd changes the angle of such antiferromagnetic coupling bonds as Fe&lt;sup&gt;3+&lt;/sup&gt;—O—Fe&lt;sup&gt;3+&lt;/sup&gt;, Fe&lt;sup&gt;3+&lt;/sup&gt;—O—Ni&lt;sup&gt;3+&lt;/sup&gt; and Ni&lt;sup&gt;3+&lt;/sup&gt;—O—Ni&lt;sup&gt;3+&lt;/sup&gt;, which leads the AFM spin states to break, and thus increases the magnetic properties. While with further modification of Nd, the drastic lattice distortion reduces the occupation of the B-sites of the magnetic ions, which might be responsible for further deteriorating the magnetic properties.

Energy-Efficiency Improvement Potential of Electric Vehicles Considering Transmission Temperature

This study presents an integrated energy and transmission thermal management system to quantify the impact of a cold-start on the energy consumption of electric vehicles (EVs) from optimal control perspective. In addition, it provides insights into reducing this cold effect from design point of view. The cold-start conditions in an EV refer to a low transmission temperature, which increases the frictional power losses caused by viscosity effects in the transmission. These losses are eventually compensated by the battery, leading to excess energy usage. A detailed EV model, especially the transmission part with transient thermodynamics based on experiment data, is developed, and the integrated energy and thermal controller aims to maximize the energy efficiency. Numerical results show that a cold-start influences the energy-saving potential, up to 2.9%. Through analysis of temperature-dependent transmission behavior and energy losses of the EV, design considerations of reducing the cold impact, thus improving energy efficiency, can be derived.

Examination of Temperature-Dependent Iron Loss Models Using a Stator Core

In order to examine the popular temperature-dependent iron loss models with unidirectional magnetization, we cut and measured a ring sample and stator core with several hundreds of combination of temperatures (RT-200 °C), frequencies (20–1 kHz), and magnetic inductions (0–1.9 T). Coefficients of various iron loss models are extracted based on the sample test, and then imported into the finite element method postprocessor to calculate the iron loss of the stator core. We found that constant coefficient loss separation temperature-dependent iron loss models can achieve a good fitting accuracy (about 5%) on ring sample in a wide range of 20–1 kHz, 0–1.9 T, RT-200 °C, while loss coefficients extracted on small ring sample could lead to 15%–20% error when predicting iron loss of larger sized stator stamp. The iron loss of silicon steel decreases with rising temperature, and thicker silicon steel is more influenced by temperature.

Thermoplastic Overmolding onto Injection-Molded and In Situ Polymerization-Based Polyamides.

We investigated products manufactured by in situ polymerization, which were reinforced with overmolded ribs. We developed our own mold and prototype product for the project. We used three different materials as preform: a material with a magnesium catalyst, manufactured by in situ polymerization, a Brüggemann AP-NYLON-based in situ polymerization material and an injection-molded PA6 (Durethan B30S, Lanxess GmbH) material. The ribs were formed from the same PA6 material (Durethan B30S, Lanxess GmbH). We examined the effect of the different technological parameters through the pull-off of the overmolded ribs. We measured the effect of melt temperature, holding pressure and holding time, and mold temperature. Considering the individual preforms, we pointed out that monomer migration and binding strength are related, which we concluded from the temperature-dependent mass loss of the materials, measured by thermogravimetric analysis (TGA). Finally, we designed a mold suitable for manufacturing overmolded parts. We designed and built pressure and temperature sensors into the mold to examine and analyze pressures and temperatures around the welding zone of the materials.

Thermal tolerance varies with age and sex for the nonnative Italian Wall Lizard (Podarcis siculus) in Southern California

Temperature has a substantial effect on both the physiology and behavior of ectothermic animals such as lizards. Physiology and behavior can also be influenced by ontogenetic and sex differences, but these effects are largely understudied in lizards. We examined ontogenetic and sex-based differences in thermal tolerances, preferred temperature, and temperature-dependent evaporative water loss rates in Italian Wall Lizards, Podarcis siculus, collected from an introduced population near Los Angeles, California, USA that were acclimated to laboratory conditions. Podarcis siculus has been introduced to multiple localities in the USA and the Mediterranean region and has demonstrated remarkable ability to adapt to novel climatic conditions. In the California population, adults of both sexes had a higher critical thermal maximum (CTmax) than juveniles, and adult females had a lower critical thermal minimum (CTmin) than juveniles and adult males. Thus, adult females had a significantly wider thermal breadth (CTmax - CTmin) compared to adult males and juveniles. Mass-specific evaporative water loss was higher in juveniles compared to adult males at intermediate temperatures. There was no significant difference among groups for preferred temperature. This implies that thermal tolerance, a physiological characteristic, varies with age and sex for this population, whereas thermal preference, a behavioral characteristic, does not. Interestingly, CTmin for all age and sex classes was above temperatures likely experienced by some nonnative populations in winter, suggesting individuals need to find urban thermal retreats. These results add to the growing literature demonstrating that thermal tolerances and breadths can vary between sexes and across age classes in squamate species.

The ionospheric response over the UK to major bombing raids during World War II

Abstract. The Earth's ionosphere is subject to disturbance from above (via solar variability and space-weather effects) and from below (such as tectonic activity, thunderstorms and sudden stratospheric warmings). Identifying the relative contribution of these effects remains challenging, despite recent advances in spacecraft monitoring near-Earth space. Man-made explosions provide a quantifiable proxy for natural terrestrial sources, enabling their impact on ionospheric variability to be studied. In this paper, the contribution of ground-based disturbances to ionospheric variability is investigated by considering the response of the ionospheric F2 layer over Slough, UK, to 152 major bombing raids over Europe during World War II, using a superposed epoch analysis. The median response of the F2 layer is a significant decrease in peak electron concentration (∼0.3 MHz decrease in foF2). This response is consistent with wave energy heating the thermosphere, enhancing the (temperature-dependent) loss rate of O+ ions. The analysis was repeated for a range of thresholds in both time of bombing before the (noon) ionospheric measurement and tonnage of bombs dropped per raid. It was found that significant (∼2–3σ) deviations from the mean occurred for events occurring between approximately 3 and 7 h ahead of the noon ionospheric measurements and for raids using a minimum of between 100 and 800 t of high explosives. The most significant ionospheric response (2.99σ) occurred for 20 raids up to 5 h before the ionospheric measurement, each with a minimum of 300 t of explosives. To ensure that the observed ionospheric response cannot be attributable to space-weather sources, the analysis was restricted to those events for which the geomagnetic Ap index was less than 48 (Kp&lt;5). Digitisation of the early ionospheric data would enable the investigation into the response of additional ionospheric parameters (sporadic E, E and F1 layer heights and peak concentrations). One metric ton of TNT has an explosive energy of 4.184×109 J, which is of the same order of energy as a cloud to ground lightning stroke. Since the occurrence of lightning has distinctive diurnal and seasonal cycles, it is feasible that a similar mechanism could contribute to the observed seasonal anomaly in ionospheric F-region electron concentrations. Further investigation, using less extreme examples, is required to determine the minimum explosive energy required to generate a detectable ionospheric response.