Transient Melting Research Articles

Synthesis and Formation Mechanism of All-Organic Block Copolymer-Directed Templating of Laser-Induced Crystalline Silicon Nanostructures.

This report describes the generation of three-dimensional (3D) crystalline silicon continuous network nanostructures by coupling all-organic block copolymer self-assembly-directed resin templates with low-temperature silicon chemical vapor deposition and pulsed excimer laser annealing. Organic 3D mesoporous continuous-network resin templates were synthesized from the all-organic self-assembly of an ABC triblock terpolymer and resorcinol-formaldehyde resols. Nanosecond pulsed excimer laser irradiation induced the transient melt transformation of amorphous silicon precursors backfilled in the organic template into complementary 3D mesoporous crystalline silicon nanostructures with high pattern fidelity. Mechanistic studies on laser-induced crystalline silicon nanostructure formation revealed that the resin template was carbonized during transient laser-induced heating on the milli- to nanosecond timescales, thereby imparting enhanced thermal and structural stability to support the silicon melt-crystallization process at temperatures above 1250 °C. Photoablation of the resin material under pulsed excimer laser irradiation was mitigated by depositing an amorphous silicon overlayer on the resin template. This approach represents a potential pathway from organic block copolymer self-assembly to alternative functional hard materials with well-ordered 3D morphologies for potential hybrid photovoltaics, photonic, and energy storage applications.

MEMOS 3D modelling of ELM-induced transient melt damage on an inclined tungsten surface in the ASDEX Upgrade outer divertor

The first MEMOS 3D simulations of liquid metal motion on an inclined bulk tungsten sample transiently molten by edge-localized modes (ELMs) are reported. The exposures took place at the outer ASDEX-Upgrade divertor with the tungsten surface tangent intersecting the magnetic field at ∼ 18°. Simulations confirm that the observed poloidal melt motion is caused by the volumetric J × B force with J the bulk replacement current triggered by thermionic emission. The final erosion profile and total melt build up are reproduced by employing the escaping thermionic current dependence on the incident heat flux derived from dedicated particle-in-cell simulations. Modelling reveals that melt dynamics is governed by the volumetric Lorentz force, capillary flows due to thermal surface tension gradients and viscous deceleration. The effect of the evolving surface deformation, that locally alters the field-line inclination modifying the absorbed power flux and the escaping thermionic current, in the final surface morphology is demonstrated to be significant.

Heat flux analysis of Type-I ELM impact on a sloped, protruding surface in the JET bulk tungsten divertor

Tungsten (W) melting due to transient power loads, for example those delivered by edge localised modes (ELMs), is a major concern for next step fusion devices. A series of experiments has been performed on JET to investigate the dynamics of Type-I ELM-induced transient melting. Following initial exposures in 2013 of a W-lamella with sharp leading edge in the bulk W outer divertor, new experiments have been performed in 2016–2017 on a protruding W-lamella with a 15° slope, allowing direct and spatially resolved (0.85 mm/pixel) observation of the top surface using the IR thermography system viewing from the top of the poloidal cross-section. Thermal and IR analysis have already been conducted assuming the geometrical projection of the parallel heat flux on the W-lamellas, thus ignoring the gyro-radius orbit of plasma particles. Although it is well justified during L-mode or inter-ELM period, the hypothesis becomes questionable during ELM when the ion Larmor radius is larger. The goal of this paper is to extend the previous analysis based on the forward approach to the H-mode discharges and investigate in particular the gyro-radius effect during the Type-I ELMs, those used to achieve transient melting on the slope of the protruding W-lamella. Surface temperatures measured by the IR camera are compared with reconstructed synthetic data from 3D thermal modelling using heat loads derived from optical projection of the parallel heat flux (ignoring the gyro-radius orbit), 2D gyro-radius orbit and particle-in-cell (PIC) simulations describing the influence of finite Larmor-radius effects and electrical potential on the deposited power flux. Results show that the ELM power deposition behaves differently than the optical projection of the parallel heat flux, contrary to the L-mode observations, and may thus be due to the much larger gyro-orbits of the energetic ELM ions in comparison to L-mode or inter-ELM conditions.

Zircon Macrocrysts from the Drybones Bay Kimberlite Pipe (Northwest Territories, Canada): A High-Resolution Trace Element and Geochronological Study

Zircon macrocrysts in (sub)volcanic silica-undersaturated rocks are an important source of information about mantle processes and their relative timing with respect to magmatism. The present work describes variations in trace element (Sc, Ti, Y, Nb, lanthanides, Hf, Ta, Pb, Th, and U) and isotopic (U-Pb) composition of zircon from the Drybones Bay kimberlite, Northwest Territories, Canada. These data were acquired at a spatial resolution of ≤100 µm and correlated to the internal characteristics of macrocrysts (imaged using cathodoluminescence, CL). Six types of zircon were distinguished on the basis of its luminescence characteristics, with the majority of grains exhibiting more than one type of CL response. The oscillatory-zoned core and growth sectors of Drybones Bay zircon show consistent variations in rare-earth elements (REE), Hf, Th, and U. Their chondrite-normalized REE patterns are typical of macrocrystic zircon and exhibit extreme enrichment in heavy lanthanides and a positive Ce anomaly. Their Ti content decreases slightly from the core into growth sectors, but the Ti-in-zircon thermometry gives overlapping average crystallization temperatures (820 ± 26 °C to 781 ± 19 °C, respectively). There is no trace element or CL evidence for Pb loss or other forms of chemical re-equilibration. All distinct zircon types are concordant and give a U-Pb age of 445.6 ± 0.8 Ma. We interpret the examined macrocrysts as products of interaction between a shallow (<100 km) mantle source and transient kimberlitic melt.

Numerical Study of Competition Effects of Laser Parameters on a Transient Melt Pool Evolution Process

The melt pool, formed by the superheated molten metal, is the initiation of solid part and the general process of laser additive manufacture process. The transient phenomena in the melt pool are of paramount interest in obtaining an optimum mechanical performance. In this paper, the different transient evolution phenomena of melt pool for the moving and fixed laser beam during the laser irradiation process are investigated, then the quantitative competition effects of the laser parameters on those transient phenomena are also studied. The results show that the evolution of melt pool gradually enters into the quasi-steady-state for the moving laser condition, the deformation of free surface almost has no change near the forward of laser beam. However, the fixed laser condition has different evolution process and the deformation of free surface becomes larger and larger even piercing the workpiece. The melt pool evolution becomes vigorous and prone to enter the quasi-steady-state with the increasing energy input per unit area which directly dominated by the laser parameters. Further investigation on the quantitative percentage of each parameter on the evolution shows that the laser scan speed is the most important factor for the evolution of melt pool.

Self-consistent description of the replacement current driving melt layer motion in fusion devices

The bulk replacement current density triggered by surface charge loss owing to thermionic emission leads to a volumetric Lorentz force which has been observed to drive macroscopic melt layer motion in transient tungsten melting tokamak experiments in which components of different geometries (deliberate leading edges and sloped surfaces) have been exposed to edge localized mode (ELM) pulsed heat loads in high power H-mode discharges. A self-consistent approach is formulated for the replacement current which is based on the magnetostatic limit of the resistive thermoelectric magnetohydrodynamic description of the liquid metal and results in a well-defined boundary value problem for the whole conductor. A new module is incorporated into the incompressible fluid dynamics code MEMOS-3D, which numerically solves the finite difference representation of the problem. The phenomenological approach, employed thus far to describe the replacement current, is demonstrated to be accurate for the sloped geometry but inadequate for the leading edge. MEMOS-3D simulations of very recent ASDEX-Upgrade leading edge experiments with the rigorous as well as the simplified approach are reported. For these simulations, the self-consistent approach predicts a fivefold reduction of the displaced material volume, a sevenfold reduction of the maximum peak height of displaced material and a different eroded surface morphology in comparison with the previously applied simplified approach.

Transient Melting at the Nanoscale: A Continuum Heat Transfer and Nonequilibrium Molecular Dynamics Approach

Transient melting is an ubiquitous phenomenon in nature, which plays an increasingly important role in the processing of nanomaterials. A sound theoretical description of this process is therefore important, both from fundamental and applied points of view. We present a numerical study of transient melting in simple atomic solids using both, continuum theory based on the heat diffusion equation and transient nonequilibrium molecular dynamics simulations. We show that continuum theory provides an accurate description of relevant properties, temperature relaxation, time-dependent internal energy, and dynamics of the melting front. However, deviations between the continuum approach and the molecular dynamics simulations are observed in picosecond time scales depending on the initial temperature used to melt the solid. These deviations are due to the emergence of new time scales associated with the activated character of the melting process. Consistently with this notion, we observe that the closer the initia...

Experimental investigation of transient melting and heat transfer behavior of nanoparticle-enriched PCM in a rectangular enclosure

Abstract An experimental study was conducted to investigate the transient melting and heat transfer behavior of nanoparticle-PCM mixtures in a rectangular enclosure. Four types of nanoparticles, silver, copper oxide, aluminum oxide and multi-walled carbon nanotubes were considered, and paraffin wax was used as the PCM. The results show that all four nanoparticle-enriched PCM mixtures provided better thermal performance as compared to the case with the plain PCM. It has been argued that the addition of surfactant to improve the suspension-ability of nanoparticles in the PCM counteracted the viscosity enhancement due to nanoparticles in the PCM. Among the four tested nanoparticles, silver nanoparticles were found to be the most effective in the heat transfer enhancement, followed by copper oxide nanoparticles. The performances of aluminum oxide and MWCNT were hampered due to their higher settlement rates. The transient heat transfer coefficients for all cases were computed and found to have increased rapidly in the early stages of melting up to the melted fraction of about 0.2, after that they remained almost constant for the rest of the melting process. The heat transfer coefficients for CuO and silver were found to be about 18% and 14% higher than the plain PCM case, while aluminum oxide and MWCNT were lower and closer to the plain PCM case due to higher sinking rates. The thermal behavior of CuO-enriched PCM was further investigated for 1, 3, 6, 8 and 10% mass fractions of CuO. It was found that under given conditions, 6% CuO fraction provides the best thermal performance and highest melting rate. For this case, the melting rate and heat flux were about 25% higher than that for the plain PCM case.

Co-development of experimental and simulation methods for the laser flash heating and melting technique: The thermoelastic effects of UO2

The thermoelastic effects on the behaviour of subsecond laser heating experiments on UO2 to temperatures approaching 3000 K are explored using a thermoelastic model coupling heat transport and large deformation hyperelasticity, with consideration of thermoelastic effects. A series of steady state experiments at temperatures up to ∼2600 K are conducted and used to calibrate heat loss models. A series of subsecond transient laser flash melting experiments are then conducted and simulated. Simulation results reproduce the observations well without tuning of the transient model. The importance of considering thermoelastic effects in modelling the behaviour of solid materials with temperature and stress gradients typical of laser flash heating experimentation is discussed.

An Analytical Technique of Transient Phase-Change Material Melting Calculation for Cylindrical and Tubular Containers

ABSTRACTIn this study, an analytical model for a class of heat storage that utilizes latent heat of a phase-change material (PCM) is developed. Two basic shell-and-tube configurations are considered, one in which the PCM melts inside the tubes while the heat transfer fluid (HTF) flows in the shell along it, and the other in which HTF flows inside the tubes while PCM melts outside. A system of partial differential equations, which describes heat transfer and melting of the PCM and heat transfer in the HTF, is derived with some simplifying assumptions, while still capturing and preserving the essential features of the processes involved. These equations are solved analytically, yielding the overall heat exchange parameters, like instantaneous heat transfer rate, stored energy, and overall operation time of the system. The present work shows that the use of the proposed analytical technique and its modifications for the practical PCM arrangements is beneficial. Proper application of the model makes it possible to obtain the parameters of a real PCM melting process in the form of algebraic formulas, both for the transient values of variables over time, and for the overall process characteristics. A comparison with the results of numerical calculations of transient melting, made using computational fluid dynamics, confirms the validity of analytical findings and allows to assess the degree of accuracy of the results of our analytical method in various practical cases.

Transient 3D simulation for heating and melting process of PWR core after SBO

In the heat transfer between the core and coolant in a reactor pressure vessel (RPV), a bounding structure such as a shroud has an important influence on the heating and melting process of the core. To study the 3D transient heat transfer and melting process of the Hualong 1 PWR using an IVR strategy, a numerical analysis model has been established based on the 2D transient heat conduction of each rod, which is coupled considering the residual heat of the core, the convective and radiation heat transfer inside the core, and natural convection heat transfer of the outer water chamber. A transient 3D numerical simulation code, 3DTMCOR, has been developed to analyze the melting process of an IVR reactor core with high precision. The effects of heat generation from a zirconium–water reaction, radiation heat transfer, and the adoption of an IVR strategy on the heating and melting process of the reactor core have been investigated. It was found that the first melting time for the same 100 MW PWR from the 3DTMCOR code is about 2500 s later than that of MAAP. The core temperature will first decrease with a decrease in core power within 100 s, then increase as the water level drops down with a zirconium–water reaction of 100 s to 1000 s, then decrease again with a decrease in core power from 1000 s to 4300 s, and increase a second time when water in the RPV is evaporated after 4300 s. At 4860 s, a continuous melting area first appears in the core top. Radiation heat exchange is very important for transferring heat from the fuel rods to structures such as the control rods and bounding structures, which is also the main cooling mode in the core after water is evaporated. The first melting time with the precise radiation exchange model will occur 200 s later than in the results with the empirical model. The water chamber outside the RPV does not have a remarkable effect on the heating and melting process of the core.

Experiments on transient melting of tungsten by ELMs in ASDEX Upgrade

Repetitive melting of tungsten by power transients originating from edge localized modes (ELMs) has been studied in ASDEX Upgrade. Tungsten samples were exposed to H-mode discharges at the outer divertor target plate using the divertor manipulator II (DIM-II) system (Herrmann et al 2015 Fusion Eng. Des. 98–9 1496–9). Designed as near replicas of the geometries used also in separate experiments on the JET tokamak (Coenen et al 2015 J. Nucl. Mater. 463 78–84; Coenen et al 2015 Nucl. Fusion 55 023010; Matthews et al 2016 Phys. Scr. T167 7), the samples featured a misaligned leading edge and a sloped ridge respectively. Both structures protrude above the default target plate surface thus receiving an increased fraction of the parallel power flux. Transient melting by ELMs was induced by moving the outer strike point to the sample location. The temporal evolution of the measured current flow from the samples to vessel potential confirmed transient melting. Current magnitude and dependency from surface temperature provided strong evidence for thermionic electron emission as main origin of the replacement current driving the melt motion. The different melt patterns observed after exposures at the two sample geometries support the thermionic electron emission model used in the MEMOS melt motion code, which assumes a strong decrease of the thermionic net current at shallow magnetic field to surface angles (Pitts et al 2017 Nucl. Mater. Energy 12 60–74). Post exposure ex situ analysis of the retrieved samples show recrystallization of tungsten at the exposed surface areas to a depth of up to several mm. The melt layer transport to less exposed surface areas leads to ratcheting pile up of re-solidified debris with zonal growth extending from the already enlarged grains at the surface.

Relict zircon U-Pb age and O isotope evidence for reworking of Neoproterozoic crustal rocks in the origin of Triassic S-type granites in South China

Granites derived from partial melting of sedimentary rocks are generally characterized by high δ18O values and abundant relict zircons. Such relict zircons are valuable in tracing the source rocks of granites and the history of crustal anatexis. Here we report in-situ U-Pb ages, O isotopes and trace elements in zircons from Triassic granites in the Zhuguangshan and Jiuzhou regions, which are located in the Nanling Range and the Darongshan area, respectively, in South China. Zircon U-Pb dating yields magma crystallization ages of 236±2Ma for the Zhuguangshan granites and 246±2Ma to 252±3Ma for the Jiuzhou granites. The Triassic syn-magmatic zircons are characterized by high δ18O values of 10.1–11.9‰ in Zhuguangshan and 8.5–13.5‰ in Jiuzhou. The relict zircons show a wide range of U-Pb ages from 315 to 2185Ma in Zhuguangshan and from 304 to 3121Ma in Jiuzhou. Nevertheless, a dominant age peak of 700–1000Ma is prominent in both occurrences, demonstrating that their source rocks were dominated by detrital sediments weathered from Neoproterozoic magmatic rocks. Taking previous results for regional granites together, Neoproterozoic relict zircons show δ18O values in a small range from 5 to 8‰ for the Nanling granites but a large range from 5 to 11‰ for the Darongshan granites. In addition, relict zircons of Paleozoic U-Pb age occur in the two granitic plutons. They exhibit consistently high δ18O values similar to the Triassic syn-magmatic zircons in the host granites. These Paleozoic relict zircons are interpreted as the peritectic product during transient melting of the metasedimentary rocks in response to the intracontinental orogenesis in South China. Therefore, the relict zircons of Neoproterozoic age are directly inherited from the source rocks of S-type granites, and those of Paleozoic age record the transient melting of metasedimentary rocks before intensive melting for granitic magmatism in the Triassic.

Simulations of thermionic suppression during tungsten transient melting experiments

Plasma-facing components receive enormous heat fluxes under steady state and especially during transient conditions that can even lead to tungsten (W) melting. Under these conditions, the unimpeded thermionic current density emitted from the W surfaces can exceed the incident plasma current densities by several orders of magnitude triggering a replacement current which drives melt layer motion via the force. However, in tokamaks, the thermionic current is suppressed by space-charge effects and prompt re-deposition due to gyro-rotation. We present comprehensive results of particle-in-cell modelling using the 2D3V code SPICE2 for the thermionic emissive sheath of tungsten. Simulations have been performed for various surface temperatures and selected inclinations of the magnetic field corresponding to the leading edge and sloped exposures. The surface temperature dependence of the escaping thermionic current and its limiting value are determined for various plasma parameters; for the leading edge geometry, the results agree remarkably well with the Takamura analytical model. For the sloped geometry, the limiting value is observed to be proportional to the thermal electron current and a simple analytical expression is proposed that accurately reproduces the numerical results.

Convective melting and freezing of phase change materials encapsulated within small diameter polymer tubes

This work characterizes the inward melting and freezing of phase change materials (PCMs) within small diameter polymer tubes under convective boundary conditions. Using air as the heat transfer fluid, a custom-built experimental apparatus was used to control the convective heating and cooling of vertically oriented PCM-filled tubes with an outer diameter of 3.175 mm. Various air speeds and air temperatures were investigated, as well as the effects of wall thickness and material properties, using three different polymer encapsulant tubes. Volume fraction, latent heat transfer rate, and the associated overall heat transfer coefficient have been measured experimentally during the transient melting and freezing processes. Using a commercially available paraffin-based PCM with a nominal melting temperature of 35 °C, phase change times ranging from 50 s to 180 s were recorded with air speeds and air temperatures of 4.7–15.3 m/s and 25.3–62.6 °C, respectively. Overall latent heat transfer coefficients as high as 200 W/m2 K were measured and shown to decay with time as the PCM changes phase during inward melting and freezing. For the thinnest encapsulants tested here, the results were consistent with a simplified one-dimensional quasi-steady-state thermal circuit model. Deviations from this model were observed and explained, including the importance of the wall thickness and thermal conductivity of the encapsulant.

Transient melting of an impure paraffin wax in a double-pipe heat exchanger: Effect of forced convective flow of the heat transfer fluid

A transient 2-D numerical study is carried out on the melting (energy storage) of an impure phase change material (paraffin wax) embedded in the annular gap formed by an outer equilateral pipe and an inner tube carrying the heat transfer fluid. A non-orthogonal curvilinear coordinate method is used to account correctly for the irregular boundaries of the annular domain. A set of parametric studies is performed by varying the bulk temperature and mass flow rate of the heat transfer fluid (HTF). Besides, numerical simulations are also made to ascertain the effects of the various cross-sectional shapes and positions of the inner tube as well as the initial state of the solid PCM on the melting process. The temporal velocity and temperature profiles are shown in addition to the cumulatively stored energy and total melt fraction as a function of the melting time. The results indicate that the bulk temperature of the HTF imposes a significant effect on the melting process compared to its mass flow rate. The lower eccentric position of the inner circular tube provides the maximum energy storage capacity compared to its concentric position. The concentrically placed circular inner tube provides the maximum energy storage in the annulus relative to the other two cross-sectional inner tubes namely prolate- and oblate-shaped elliptical tubes.

Investigation of transient melting of tungsten by ELMs in ASDEX Upgrade

Repetitive melting of tungsten by power transients originating from edge localized modes (ELMs) has been studied in the tokamak experiment ASDEX Upgrade. Tungsten samples were exposed to H-mode discharges at the outer divertor target plate using the Divertor Manipulator II system. The exposed sample was designed with an elevated sloped surface inclined against the incident magnetic field to increase the projected parallel power flux to a level were transient melting by ELMs would occur. Sample exposure was controlled by moving the outer strike point to the sample location. As extension to previous melt studies in the new experiment both the current flow from the sample to vessel potential and the local surface temperature were measured with sufficient time resolution to resolve individual ELMs. The experiment provided for the first time a direct link of current flow and surface temperature during transient ELM events. This allows to further constrain the MEMOS melt motion code predictions and to improve the validation of its underlying model assumptions. Post exposure ex situ analysis of the retrieved samples confirms the decreased melt motion observed at shallower magnetic field line to surface angles compared to that at leading edges exposed to the parallel power flux.

Verification and validation of a rapid heat transfer calculation methodology for transient melt pool solidification conditions in powder bed metal additive manufacturing

A fundamental understanding of spatial and temporal thermal distributions is crucial for predicting solidification and solid-state microstructural development in parts made by additive manufacturing. While sophisticated numerical techniques that are based on finite element or finite volume methods are useful for gaining insight into these phenomena at the length scale of the melt pool (100–500μm), they are ill-suited for predicting engineering trends over full part cross-sections (>10×10cm) or many layers over long process times (>many days) due to the necessity of fully resolving the heat source characteristics. On the other hand, it is extremely difficult to resolve the highly dynamic nature of the process using purely in-situ characterization techniques [1]. This paper proposes a pragmatic alternative based on a semi-analytical approach to predicting the transient heat conduction during powder bed metal additive manufacturing processes. The model calculations were theoretically verified for selective laser melting of AlSi10Mg and electron beam melting of IN718 powders for simple cross-sectional geometries and the transient results are compared to steady state predictions from the Rosenthal equation. It is shown that the transient effects of the scan strategy create significant variations in the melt pool geometry and solid-liquid interface velocity, especially as the thermal diffusivity of the material decreases and the pre-heat of the process increases. With positive verification of the strategy, the model was then experimentally validated to simulate two point-melt scan strategies during electron beam melting of IN718, one intended to produce a columnar and one an equiaxed grain structure. Through comparison of the solidification conditions (i.e. transient and spatial variations of thermal gradient and liquid-solid interface velocity) predicted by the model to phenomenological CET theory, the model accurately predicted the experimental grain structures.

Transient induced tungsten melting at the Joint European Torus (JET)

Melting is one of the major risks associated with tungsten (W) plasma-facing components (PFCs) in tokamaks like JET or ITER. These components are designed such that leading edges and hence excessive plasma heat loads deposited at near normal incidence are avoided. Due to the high stored energies in ITER discharges, shallow surface melting can occur under insufficiently mitigated plasma disruption and so-called edge localised modes—power load transients. A dedicated program was carried out at the JET to study the physics and consequences of W transient melting. Following initial exposures in 2013 (ILW-1) of a W-lamella with leading edge, new experiments have been performed on a sloped surface (15 slope) during the 2015/2016 (ILW-3) campaign. This new experiment allows significantly improved infrared thermography measurements and thus resolved important issue of power loading in the context of the previous leading edge exposures. The new lamella was monitored by local diagnostics: spectroscopy, thermography and high-resolution photography in between discharges. No impact on the main plasma was observed despite a strong increase of the local W source consistent with evaporation. In contrast to the earlier exposure, no droplet emission was observed from the sloped surface. Topological modifications resulting from the melting are clearly visible between discharges on the photographic images. Melt damage can be clearly linked to the infrared measurements: the emissivity drops in zones where melting occurs. In comparison with the previous leading edge experiment, no runaway melt motion is observed, consistent with the hypothesis that the escape of thermionic electrons emitted from the melt zone is largely suppressed in this geometry, where the magnetic field intersects the surface at lower angles than in the case of perpendicular impact on a leading edge. Utilising both exposures allows us to further test the model of the forces driving melt motion that successfully reproduced the findings from the original leading edge exposure. Since the ILW-1 experiments, the exposed misaligned lamella has now been retrieved from the JET machine and post mortem analysis has been performed. No obvious mass loss is observed. Profilometry of the ILW-1 lamella shows the structure of the melt damage which is in line with the modell predictions thus allowing further model validation. Nuclear reaction analysis shows a tenfold reduction in surface deuterium concentration in the molten surface in comparison to the non-molten part of the lamella.

Late Noachian Icy Highlands climate model: Exploring the possibility of transient melting and fluvial/lacustrine activity through peak annual and seasonal temperatures

Late Noachian Icy Highlands climate model: Exploring the possibility of transient melting and fluvial/lacustrine activity through peak annual and seasonal temperatures