Unit Mass Research Articles

Natural mineral raw materials as granular filtering materials in industrial and waste water treatment

Analysis of currently existing methods of natural and waste water treatment from heavy metals has shown that one of the most promising is the sorption method using natural inorganic materials as sorbents: zeolite, diatomite, and vermiculite. The relevance of the topic is dictated by the need to develop an original technology of wastewater treatment and water treatment, which allows constant monitoring of the level of pollution of natural waters by industrial wastewater from metallurgical enterprises. The proposed methods of sorbent modification create a basis for studying the structure, porosity, and sorption capabilities of the mentioned natural materials. All three minerals: zeolite, diatomite, and vermiculite belong to highly porous, structured materials, promising for use as stable sorption systems in water treatment and water purification. The influence of physical and chemical characteristics of natural sorbents and the application of new promising environmentally safe materials and reagents for water treatment are considered. The sorption of copper ions on natural zeolite material before and after its modification by hydrothermal method was investigated. The activity of sorbents was estimated by the value of sorption capacity, i.e. the amount of heavy metal ions absorbed by a unit mass of sorbent based on zeolite and its modified form.

Phosphorus Enrichment by ONe Novae in the Galaxy

Recent observations have shown that [P/Fe] in the Galactic stars decreases with increasing [Fe/H] for [Fe/H] ≳ − 1 whereas it is almost subsolar for [Fe/H] ≲ −2. These [P/Fe] trends with [Fe/H] have not been well reproduced by previous theoretical models incorporating phosphorus (P) enrichment only by core collapse supernoave. We here show, for the first time, that the trends can be naturally explained by our new models incorporating P enrichment by oxygen–neon (ONe) novae, which occur at the surface of massive white dwarfs whose masses are larger than 1.25M ⊙ with a metallicity-dependence rate. We also show that the observations can be better reproduced by the models by assuming that (i) the total mass of gaseous ejecta per ONe nova (M ej) is as high as 4 × 10−5 M ⊙ and (ii) the number of such novae per unit mass (N ONe) is as large as 0.01 at [Fe/H] ≈ −3. The assumed M ej is consistent with observations, and the high N ONe is expected from recent theoretical models for ONe nova fractions. We predict that (i) [P/Fe] increases with increasing [Fe/H] for −2 ≲ [Fe/H] ≲ −1 and (ii) [P/Fe] and [Cl/Fe] trends with [Fe/H] are very similar to each other due to very large yields of P and Cl from ONe novae. It is thus worthwhile for future observations to assess the validity of the proposed P enrichment by ONe novae by confirming or ruling out these two predictions.

Lightweight design of lattice structure of boron steel prepared by selective laser melting

Three-cycle minimum surface structures show excellent lightweight and energy absorption capabilities, and additive manufacturing techniques provide a unique degree of freedom for lattice structure design. Therefore, in this study, three-period minimum surface (TPMS) structures of Schwarz-P boron steel alloys were prepared by Selective Laser Melting (SLM) technique. By investigating the effect of lattice structure design, we have analyzed the deformation behavior, mechanical properties and energy absorption capacity under compression. In addition, tensile properties and fracture morphology were analyzed to gain insight into the performance characteristics of these structures, and the effect of structural design on hardness was explored. The results of the study show that the structural design has a small effect on the microstructure and hardness. Under compressive loading, the P (0.5 1) structure exhibits a uniform deformation behavior, while the other four structures show a crushing deformation pattern. In particular, the P (0.5 1) structure exhibits excellent compressive performance, with an energy absorption work per unit mass as high as 296.2 J/mm^3, and its stiffness reaches 1627 MPa. Meanwhile, the P (0.35 1) structure exhibits excellent tensile performance with the tensile strength of 687 MPa. The morphological analysis of the tensile fracture reveals that the fracture mainly occurs in the strut nodes, and it mainly exhibits ductile tensile fracture.

Presupernova Evolution and Explosive Nucleosynthesis of Rotating Massive Stars. II. The Supersolar Models at [Fe/H] = 0.3

We present an extension of the set of models published in Limongi & Chieffi (2018) at metallicity 2 times solar, i.e., [Fe/H] = 0.3. The key physical properties of these models at the onset of core collapse are mainly due to the higher mass loss triggered by the higher metallicity: the supersolar metallicity (SSM) models reach core collapse with smaller He- and CO-core masses, while the amount of 12C left by the central He burning is higher. These results are valid for all the rotation velocities. The yields of the neutron-capture nuclei expressed per unit mass of oxygen (i.e., the X/O) are higher in the SSM models than in the SM ones in the nonrotating case, while the opposite occurs in the rotating models. The trend shown by the nonrotating models is the expected one, given the secondary nature of the neutron-capture nucleosynthesis. Vice versa, the counterintuitive trend obtained in the rotating models is the consequence of the higher mass loss present in the SSM models, removes the H-rich envelope faster than in the SM models while the stars are still in central He burning, dumping out the entanglement (activated by the rotation instabilities) and therefore conspicuous primary neutron-capture nucleosynthesis.

Application of Calcium Carbonate in the Pharmaceutical Removal Process

One way to reduce the negative impact of human activity on the natural environment is to use natural, easily available and relatively cheap to produce compounds in industrial processes. One such compound is naturally occurring calcium carbonate (CaCO3). This compound has adsorption properties so that it can be an alternative to commonly used adsorbents. The aim of this work is to determine the possibility of using CaCO3 to remove pharmaceutical substances such as sulfadiazine and tetracycline from water. The CaCO3 used in this work was synthesised using our own method, which allows the production of CaCO3 particles with nanometric size. In the conducted research, calcium carbonate was used in the form of a suspension in purified solutions and as an inorganic filling of the developed membranes. The mass of pharmaceutical substances removed from their aqueous solutions was determined in the tests carried out. Based on the results obtained, it can be concluded that CaCO3 has the ability to adsorb both tetracycline and sulfadiazine. In suspension tests, the mass of the removed substances per unit mass of adsorbent was 1.52 mg/g and 6.85 mg/g, respectively. In turn, in the case of the integrated process using the developed membranes, the mass of the removed substances per unit mass of adsorbent was 109 mg/g and 97 mg/g.

Energy absorption characteristics of novel bionic H-type whip restraints for nuclear power plants

To enhance the efficiency of energy absorption in H-type whip restraints for nuclear power plants, this study takes inspiration from the asymmetric twisted lines observed in the Nautilus shell, introducing the Nautilus Bionic Hierarchical Multi-Cell (NBHMC) structure. For different high-energy pipeline sizes and energy absorption quantities, the proposed structures are miniaturized and can be combined into H-type whip restraint by multiple tubes to meet the requirements. The NBHMC structures are investigated based on the validated finite element method, the results demonstrate that the energy absorption per unit mass of the new structure can reach up to 180% of that of the hollow tube, with the maximum enhancement in energy absorption efficiency being 47%. Through parameter analysis of the cross-sectional wall thickness, the highest energy absorption efficiency obtained is 99.62%, with a specific energy absorption of 31.29J/g. Furthermore, utilizing the TOPSIS method, all proposed parameter combinations are ranked, leading to the determination of the optimal parameter combination. Additionally, a theoretical model predicting the mean crushing force is introduced, exhibiting good agreement with numerical simulations. The results presented in this work provide innovative insights for the design of efficient pipe whip restraints.

Regulation of the interaction of heat exchange and throttling effect for a Joule-Thomson cooler with rectangular microchannels

Applying microchannels in Joule-Thomson (J-T) coolers can enhance precooling. The regulation of heat transfer and throttling is crucial to lower the cold terminal temperature Tcold.The present cooler with rectangular microchannels served as the prototype. The experiments were carried out under 4, 5 and 6 MPa, with Ar and N2 as the refrigerants. The cooler can achieve the lowest cold terminal temperature (Tcold, 194.9 K) at 6 MPa. Then, the mathematical model was verified. The analysis showed that under the premise of constant total length and working condition, the precooled temperature before throttling could be reduced, and finally, the Tcold could be reduced. There are two ways to regulate. On the one hand, extending the recuperative structure (CFHX)’s length and reducing the length and cross-sectional flow area of the throttling structure (THR). This regulation increased the heat exchange per unit mass qm and the integral throttling effect ΔTjt in each section and finally reduced the Tcold. When the length of THR was decreased to 15 mm, and the end of THR reached the chocked flow, the Tcold reached the lowest value of 166.3 K. On the other hand, when fins were added in CFHX, THR became shorter. This method enhanced the precooling at the expense of pressure drop in CFHX. When the fins’ number raised from 0 to 6, Tcold declined. When the number is 6, the Tcold decreased by 7.7 K. As the number went on rising, the performance eventually deteriorated.

Energy absorption characteristics and multi-objective optimization of 3D bionic negative Poisson’s ratio honeycomb

This paper introduces a new bionic cell element with a negative Poisson’s ratio, which is derived from the traditional re-entrant hexagonal cell element. By incorporating rotation into the two-dimensional (2D) cell element, a three-dimensional (3D) cell element is formed, which exhibits enhanced mechanical properties. The 3D honeycomb is obtained by arraying the 3D cell elements and is enhanced by adding longitudinal ribs to the honeycomb. The present study employs the ABAQUS/EXPLICIT software to investigate the correlation between various compression velocities and the crashworthiness and energy absorption capacity of a given system. The effects of different compression velocities on the 3D honeycomb deformation pattern and energy absorption performance are analyzed. The simulation results show that the new bionic negative Poisson’s ratio honeycomb has better crashworthiness and energy absorption capacity than the traditional re-entrant hexagonal honeycomb. The nominal stress-strain curves of different honeycombs and the energy absorbed per unit mass of honeycomb are compared and analyzed, and the NSGA-II genetic algorithm is used to perform a multi-objective optimization analysis of the peak stress and energy absorbed per unit mass of honeycomb. The results show that the optimized honeycomb can increase the absorbed energy per unit mass by 7.5 % when the peak stress is the same as the initial honeycomb, while the peak stress can be reduced by 9.6 % when the absorbed energy per unit mass is the same.

Discontinuous Atmospheric Pressure Interface in-Trap Single Photon Ionization Ion Trap Mass Spectrometry (DAPI in-Trap SPI ITMS)

A compact in-trap single photon ionization (SPI) system, termed discontinuous atmospheric pressure interface (DAPI) ion trap mass spectrometry (ITMS), for the rapid determination of trace volatile organic compounds (VOCs). DAPI enables the maintenance of high analyte pressure in the SPI source while preserving the vacuum. Utilizing vacuum ultraviolet (VUV) lamp as the ion source, we ionize the analyte within an enclosed miniature 3D ion trap for efficient analysis. Experimental findings demonstrate that the system achieves a mass resolution of less than 0.5 atomic mass units for full width at half maxima (FWHM), providing unit resolution. For the response for benzene, the system achieves almost instantaneous response, with rise and fall times of only 2 s, which is a significant advantage compared to the membrane inlet (MI) approach necessary for on-site detection. Additionally, tandem mass spectrometry (MS/MS) with unit m/z isolation window was achieved and resolved dimethyl disulfide and phenol with similar molecular weights. Our results demonstrate that the system provides excellent performance and we anticipate its application in rapidly determining VOCs.

Introducing and performance evaluation of a novel Multi-Generation process for producing Power, fresh Water, oxygen and nitrogen integrated with liquefied natural gas regasification and carbon dioxide removal process

The objective of this paper is to develop and evaluate a new integrated multigenerational system comprised of cryogenic air separation, hydrate-based desalination, combined cycle and oxyfuel power plants, carbon dioxide amine absorption, and transcritical carbon dioxide power cycle, employing liquefied natural gas cold energy. This integrated multi-generation system, applicable for liquefied natural gas importer terminals with access to seawater, produces approximately 2,533 MW net output power and 1,985 kg/h fresh water. In addition, this integrated multi-generation process produces 16,735,861 kg/h high-purity liquid oxygen (100 mol%), 4,773,633 kg/h liquid nitrogen with 99.71 mol% purity, more than 31,724,465 kg/h high-purity gaseous nitrogen (99.9 mol%), and 90,903,230 kg/h low-purity gaseous nitrogen (83.38 mol%). About 5907.3 MW of produced power is generated by liquefied natural gas expander. The performance of this system is evaluated by energetic methods. The results of energy analysis show the specific energy consumptions of the air separation products are 0.551 kW/kg and 1.93 kW/kg for liquid oxygen and nitrogen, respectively. Moreover, in the hydrate-based desalination subsystem, the specific energy consumption is 0.5 kW/m3 for produced pure water. The combined cycle power plant includes two gas turbines, three steam turbines, and a three-pressure level heat recovery steam generation. The thermal efficiencies of gas turbine cycles (Bryton), steam turbine cycles (Rankine) and combined power cycles are 26.3 %, 29.6 %, and 36.2 %, respectively. The flue gases from power plants enter the carbon dioxide amine absorption subsystem. The separated carbon dioxide is used as a working fluid to produce 372.1 MW power in transcritical carbon dioxide cycle. The results of energy analysis for carbon dioxide amine absorption subsystem show that the specific energy consumption, the ratio of captured carbon dioxide per unit mass of liquefied natural gas and the carbon dioxide removal efficiency are 6.60 kW/kg, 33.91 kg/tone, and 90.06 %, respectively. Approximately 2,905,000 kg/h of liquid carbon dioxide is obtained as the byproduct of this multi-generation process. Additionally, sensitivity analysis is conducted to determine key parameters influencing the main energetic indexes. Finally, the amount of attainable regasified natural gas reaches 257,523 tone/h by applying this multi-generation system with total 86 % energy efficiency.

Incomplete solid fuel burning as the major emission source of atmospheric phenols and environmentally persistent free radicals

Environmentally persistent free radicals (EPFRs) bonded to fine particle matters (PMs) are known to cause adverse health impacts. This study comprehensively addressed their emission sources and major precursors including phenols, based on field measurements and inventory estimation. The emission characteristics of phenols and EPFRs were obtained through direct measurement of PM2.5 and gaseous samples, collected from various real-world anthropogenic sources. The residential sector (coal and biomass combustion) was revealed to produce the highest level of EPFRs (0.66 to 3.21 × 1017 spins/g) and phenols (5.8 to 55.9 mg/g) per unit mass of emitted PM2.5 amidst all estimated samples, including power plant, various industrial processes, and transportation sources. Additionally, the emission of phenols strongly correlates with that of EPFRs, indicating an EPFR transition pathway during the pyrolysis process of lignin. Furthermore, the residential sector contributed approximately 80.6 % of atmospheric EPFRs and 99.9 % of phenols as primary emitted PM2.5 in mainland China in 2019. Much higher levels of primary phenols and EPFRs presented in agricultural regions, where biomass was commonly used as household fuel. The obtained results highlight that the pollution control of residential solid fuel burning can efficiently relieve the negative impacts associated with atmospheric phenols and EPFRs.

Study on the crashworthiness of multi-cell thin-walled tubes filled with triply periodic minimal surface lattices

To improve energy absorption and efficiency and develop a structure with outstanding energy absorption capability, this study proposed designing multi-cell tubes filled with triply periodic minimal surface (TPMS) lattices. Based on experimental and simulation methods, the crashworthiness of multi-cell tubes filled with three types of TPMS lattices (Diamond, Gyroid, and Primitive) was investigated. Five multi-cell tube structures were fabricated by increasing the thin-walled tube corner units, improving the energy absorption efficiency by 67.98%. The results show that due to the coupling between TPMS lattices and thin-walled tubes, multi-cell tubes filled with TPMS lattices exhibited better crashworthiness performance. The energy absorption of multi-cell tubes filled with Diamond, Gyroid, and Primitive lattices increased sequentially. The energy absorption per unit mass and energy absorption capability were most notably enhanced for the multi-cell tubes filled with Diamond lattice, with energy absorption efficiency 17.24% higher and energy absorption 104.26% greater than empty multi-cell tubes. This inspires crash designs of rail vehicles and automotive fronts.

Compressive properties of a modified re-entrant chiral auxetic structure (MRCA) under uniaxial quasi-static loading

Auxetics are a unique class of innovative materials/structures. Auxetic material/structures possess a negative value of Poisson’s ratio owing to the distinguished deformation behavior represented by the transvers expansion or contraction when they experience uniaxial stretching or compression, respectively. The aim of this manuscript is to show contributions of the structural modification on an auxetic hybrid structure. The in-plane properties of an auxetic structure, called the modified re-entrant chiral auxetic (MRCA) structure under quasi-static compression were experimentally and numerically explored. The experimental specimens were 3D printed using fused deposition modeling technique. The commercial ABAQUS/Explicit solver was used to develop the simulated models. Results showed that the structural modification have led to effectively improve deformation coordination (i.e. uniform deformation patterns) and the compressive properties of the modified structure. Young’s moduli were 1.75 and 12.7 higher than those of the original geometry, while values of plateau stress were 3.1 and 1.23 higher than those of the original geometry when they were compressed along the X and Y axes, respectively. The specific energy absorptions per unit mass were 4.7 J g−1 and 3.9 J g−1 when the MRCA specimens were compressed along the X and Y axes, respectively. However, the added cylinders limited the auxeticity (i.e. the transvers contraction) of the specimens during the compression tests.

Measurement of mass force field driving water refilling of cuttage

Cuttage is a common plant cultivation method, and the key to its survival is the restoration of water refilling, which remains unclear up to now. We report 3D dynamic imaging of water refilling of cuttage without resorting to any contrast agent. Hydrodynamics of the refilled water flow over time reveals the existence of a unit mass force field with a gradient along the refilling direction, which means that cutting plants also have a gradient force field to drive the recovery of water refilling, as predicted by Cohesion-Tension theory in normal plants. We found that force fields of different functional regions are isolated and independently distributed, which is conducive to ensure the safety of water transmission. At the same time, we also found that there is a so-called "inchworm effect" in the mass force field, which contributes to the force transfer inside the cutting through local force accumulation. Results of this paper demonstrate that the developed method for the measurement of mass force field in-vivo is applicable to help decipher the mechanism of plant water refilling.

Dynamic analysis of a tensegrity-based traction structure

Purpose This study proposes a tensegrity-based traction structure with D-bar dual cable units. It is used to connect the airship and the ground to stabilize the airship.Design/methodology/approach The mathematical models and dynamic models of the D-bar dual cable (hereafter referred to as DD cable) unit of the tensegrity-based traction structure are established. Based on the minimum mass method, the mass of the DD cable unit in the critical state (cable member is yielding, or bar member is buckling or yielding) is analyzed. Then, the tensile strength of the DD cable unit and single cable unit under the same condition is compared using the control variate method. Finally, based on ANSYS dynamic simulation, the stability of the two structures under the same external force disturbance was tested.Findings Expressions for the minimum mass of the DD cable unit under different failure conditions are solved. Dynamic simulation results show that the capacity of resisting disturbance of the DD cable unit is much better than that of the single cable unit under the same wind speed. So, we find a structure more suitable for the fixed connection of an airship.Originality/value This study helps to provide theoretical reference and thinking for the practical application of the traction structure with a D-bar dual cable unit.

Thermal performance of polymer gyroid heat exchangers combined with phase change materials as a latent heat thermal energy storage system: An experimental investigation

Latent heat thermal energy storage (LHTES) systems utilizing phase-change materials (PCMs) in conjunction with heat exchangers (HXs) have been widely investigated for efficient thermal energy utilization. This study experimentally evaluated the heat transfer performance and pressure loss of a PCM-based gyroid HX fabricated using a polymer 3D printer. Initially, the study compared the phase change time, heat storage and release characteristics, and pressure drop of the gyroid HX with those of a conventional shell-and-tube HX (S&T HX). The results demonstrate that the gyroid HX achieved up to 20 % shorter thermal charge and discharge times than the S&T HX, which is attributed to a higher heat transfer rate. Additionally, the measured pressure drop of the gyroid HX was up to 44 % lower than that of the S&T HX. Consequently, considering both the heat transfer rate and pressure drop, the gyroid HX showed an average improvement of 57 % and 31 % in the overall enhancement factor during charging and discharging, respectively, compared to the S&T HX. Further, metal gyroid HXs fabricated from steel and aluminum using metal 3D printing were experimentally compared with the polymer gyroid HX. Despite the polymer thermal conductivity being only 1/90 and 1/790 that of steel and aluminum, respectively, the heat transfer rate per unit mass of the polymer gyroid HX was 1.7 times that of the steel gyroid HX and approximately half that of the aluminum gyroid HX. This finding suggests that the polymer gyroid HX is suitable for LHTES applications where lightweight characteristics are crucial.

Determination of effective atomic number, electron density and Kerma of some ferroelectric materials using mass attenuation coefficients in the energy range 1 keV -100 GeV

The effective atomic number Zeff and the corresponding effective electron density Nel of ferroelectric materials (BaCoF4, LiNbO3, KNbO3, BaTiO3, PbZrO3, PbTiO3, KNbO3, Bi4Ti3O12, KHPO4, PbBi2Nb2O9, SrBi2Ta2O9, Ba0.73Sr0.27TiO3 and Mg3B7O13Cl) has been calculated in the extended energy region from 1 keV – 100 GeV using WinXCom program. The total photon interaction with coherent and incoherent one can distinguish three energy regions are approximately E<1 keV, 10 keV<E<1 GeV and E>10 GeV. The main photon interaction processes in these regions are photoelectric absorption, incoherent (Compton) scattering and pair production. Zeff and Nel values also have been obtained for different processes such as coherent and incoherent scattering pair production in nuclear and electric field, photoelectric absorption and the variations are shown graphically. The variations are due to the presence of different elements in a compound. The behaviour of the energy dependence of electron density is similar to the energy dependence of effective atomic number. The photoelectric absorption is dominant for total coherent process for Kinetic energy released per unit mass (Kerma). Direct method is one of the method helpful to calculate effective atomic number for all types of materials, for all energies greater than 1 keV.

Investigation of the fracture resistance of high strength ferritic steel welds in gaseous hydrogen environment

Hydrogen is expected to play a major role in the decarbonization of the energy grid. As a fuel, it possesses an elevated energy density per unit mass, about twice as much as natural gas but also a very low mass density; for this reason, it is preferably stored and transported at elevated pressures in the gas phase to achieve a comparable volumetric energy density. High strength quenched and tempered ferritic steels are widely used for gaseous hydrogen storage despite the fact that hydrogen affects material properties and result in higher fatigue crack growth rate and lower fracture toughness.This work presents the results of a comprehensive fracture toughness test program in gaseous hydrogen for the characterization of base metal, heat affected zone and weld metal on a high strength, quenched and tempered steel, suitable for the construction of hydrogen pressure equipment.Full penetration, butt welded joints were made using partly mechanized gas metal arc welding technique on a weldable, high strength steel, namely EN 101216-3 grade P690 QL2. Two different welding procedures were evaluated, and fracture toughness tests were conducted according to ASTM E1820 requirements, in high purity (99.9995%) hydrogen gas at a pressure of 200 bar on specimens extracted from base metal, heat affected zone and weld metal. While base metal and weld metal exhibited stable crack growth behavior, heat affected zone showed variable behavior as a function of the post-weld heat treatment conditions. It was found that local micro-hardness spots are a concern and should be controlled through dedicated post weld heat treatment operation to limit hardness values for use of welds in H2 gas conditions.

Charging kinetics of a vibrated bed of particles by numerical simulations and experiments

Through particle dynamics simulations and experiments, we investigate the charging kinetics of a granular bed in a vibrating cell. The numerical method is based on a theoretical model combining an equation for charge transfer at the particle scale with a theoretical model of charge relaxation. Simultaneously, experiments are carried out to calibrate and validate the numerical model using a vibrated cell with glass beads. Specific charge per unit mass induced by vibrations initially increases before leveling off. Saturation specific charge and charging characteristic time decrease with increasing bed mass. Data collapse onto a master curve is observed when normalizing specific charges and times. At the particle scale, we find that charge saturation results from the balance between charge transfer and relaxation. Saturation specific charge correlates with the relative rate of collisions between particles and the vibrating plate. We introduce a simple expression for the average ballistic time based on single-particle dynamics and a restitution coefficient dependent on bed mass. The characteristic time is proportional to the ballistic time and decreases with increasing bed mass due to more inelastic collisions between particles.

A criterion of dimensional design to improve flame spread resistance of magnesium alloy components

A criterion for predicting the flame spread time of stick-shaped Mg alloy samples was proposed based on the law of energy conservation. It is indicated that the flame spread time is mainly affected by the material and sample dimension. The initial temperature and ignition temperature of the control volume and the S/lc ratio (the cross-sectional area/cross-sectional circumference) of the sample are decisive for the flame spread time. The flame spread time is proportional to the ΔH (the energy required to heat a unit mass of sample from initial temperature to ignition temperature) and the S/lc ratio, which is confirmed in three Mg alloys of Mg–8.5Al–0.5Zn–0.2Mn, Mg–2.7Nd– 0.4Zn–0.6Zr and Mg–4.0Y–3.3Nd–0.5Zr. For samples with the same dimension, the Mg–8.5Al–0.5Zn–0.2Mn alloy sample possesses the largest ΔH and the longest flame spread time. For samples with constant length and cross-sectional area, the sample with circular cross-section has the largest S/lc ratio and the best flame spread resistance in the same alloy.