Cluster Size Research Articles

Directed Electron Modulation Stabilizes Iridium Oxide Clusters for High‐Current‐Density Oxygen Evolution

AbstractThe rapid advancement of the green hydrogen industry has driven a surge in demand for devices that operate over a broad range of current density. Despite this, the development of stable iridium‐based catalysts for high‐current‐density applications in oxygen evolution reactions remains a significant challenge. In this study, directed electron modulation (DEM) of iridium oxide clusters on cobalt hydroxide nanosheets is achieved using a cyclic Joule heating strategy in pure water. The strategy achieves a rapid change of environmental energy during electronic modulation through Joule heating, which ensures strong electronic coupling between IrO2 and Co(OH)2 without significant changes in initial catalyst nanostructure and cluster size. Directed electron modulation optimizes the reactant adsorption ability of the active center (IrO2 cluster) and corresponding reaction kinetics are improved, resulting in the catalyst (DEM‐IrO2@Co(OH)2‐NF) showing excellent performance. The DEM‐IrO2@Co(OH)2‐NF exhibits excellent catalytic activity in alkaline electrolytes with only 296 mV overpotential up to 1 A cm−2 and no significant degradation in 1000 h stability test at 1 A cm−2. Additionally, the anion exchange membrane electrolyzer using DEM‐IrO2@Co(OH)2‐NF||Pt/C requires only 1.68 V at 1 A cm−2 and remains stable for 200 h. This work will provide new directions for optimization of active centers.

Enhancing the Electronic and Optical Properties of Germanium Nanoclusters through Alkali Metal Doping: A Case Study on Na₂

Abstract In the present study, we have examined the key insight into structural, electronic, and optical properties of Na2 doped germanium nano-cluster using density functional theory. Analysis of binding energy (BE) indicates enhanced thermodynamical stability increases with cluster size, where Ge5Na2 and Ge10Na2 exhibiting highest BE. Second order energy suggest that cluster with n = 2, 5, 6, and 9 are most stable while thpse with n = 3, 4, and 7 shows lower stability. Embedding energy (EE) shows decreases curve with cluster size indicating large clusters are more favourable for Na encapsulation. Large HOMO-LUMO gap ranges from 1.4 to 3.2eV illustrate semiconductor nature of clusters. Further investigation of hyperpolarizability suggesting non-linear optical (NLO) activity for GenNa2 (n = 1-4), while lower NLO features shown in high symmetry clusters with n = 5 and 6. These results imply that GenNa2 clusters have potential uses in optoelectronic and semiconductor devices.

Sensitivity of Functional Arterial Spin Labelling in Detecting Cerebral Blood Flow Changes

Aims/Background Arterial spin labelling (ASL) is a non-invasive magnetic resonance imaging (MRI) method. ASL techniques can quantitatively measure cerebral perfusion by fitting a kinetic model to the difference between labelled images (tag images) and ones which are acquired without labelling (control images). ASL functional MRI (fMRI) provides quantitative perfusion maps by using arterial water as an endogenous tracer instead of depending on vascular blood oxygenation level.This study aimed to assess the number of pulsed ASL blocks that were needed to provide accurate and reliable regional estimates of cerebral blood flow (CBF) changes when participants engaged in visually guided saccade and fixation task; evaluate the localization to cortical control saccade versus fixation; investigate the relationship between the sensitivity of ASL fMRI and the number of blocks; and compare the sensitivity of blood oxygen level-dependent (BOLD) fMRI and ASL fMRI. Methods The experiment was a block-design paradigm consisting of two conditions: fixation and saccade. No response other than the eye movements of the participants was recorded during the scans. ASL and BOLD fMRI scans were conducted on all participants during the same session. The fMRI study consisted of two functional experiments: a CBF contrast was provided using the ASL sequence, and an optimized BOLD contrast was provided using the BOLD sequence. Results From group analysis in all divided blocks of ASL sessions (4, 6, 8...... 14, 16, 18......26, 28, 30), ASL yielded significant activation clusters in the visual cortex of the bilateral hemisphere from block 4. There was no false activation from block 4. No activation cluster was found by reversing analysis of block 2. Robust and consistent activation in the visual cortex was observed in each of the 14 divided blocks group analysis, and no activation was found in the eye field of the brain. The sensitivity of 4-block was found to be better than that of 8-block. More significant activation clusters of the visual cortex were found in BOLD than in ASL. No activation cluster of parietal eye field (PEF), frontal eye field (FEF) and supplementary eye field (SEF) was detected in ASL. The voxel size of the activation cluster increased with the increasing number of blocks, and the percent signal change in the activation cluster decreased with the escalating block number. The voxel size was positively correlated with the number of blocks (correlation coefficient = 0.98, p < 0.0001), and the percent signal change negatively correlated with the number of blocks (correlation coefficient = –0.90, p < 0.0001). Conclusion The 4-block pulsed functional ASL (fASL) presents accurate and reliable activation, with minimal time-on-task effect and little adverse impact of time, in participants engaging in visually guided saccade and fixation tasks. Despite having lower sensitivity than BOLD fMRI, ASL can determine accurate activation location. Although the time-on-task effects affect the observation for the sensitivity of ASL over task time, it is suggested that ASL fMRI may provide a powerful method for pinpointing the time-on-task effect over a long period of time.

Noise and cluster size insensitive robust weighted fuzzy clustering for medical image segmentation

Noise and cluster size insensitive robust weighted fuzzy clustering for medical image segmentation

Two tests of variance homogeneity for clustered data where group size is informative

To evaluate variance homogeneity among groups for clustered data, Iachine et al. (Robust tests for the equality of variances for clustered data. J Stat Comput Simul 2010;80(4):365–377) introduced an extension of the well-known Levene test. However, this method does not account for informative cluster size (ICS) or informative within-cluster group size (IWCGS), which can occur in clustered data when cluster and group sizes are random variables. This article introduces two tests of variance homogeneity that are appropriate for data with ICS and IWCGS, one extending the Levene-style transformation method and one based on a direct comparison of estimates of variance. We demonstrate the properties of our tests in a detailed simulation study and show that they are resistant to the potentially biasing effects of ICS and IWCGS. We illustrate the use of these tests by applying them to a data set of x-ray diffraction measurements collected from a specimen of duplex steel.

[formula omitted]-core percolation and node protection strategy for edge-coupling partially interdependent networks

In the real-world, there exist mutual dependencies among not only nodes but also edges. Consequently, the study on the robustness of edge-coupling interdependent networks has emerged as a highly focused area. By analyzing the characteristics of interdependent networks, a relevant k-core percolation model is proposed. Given that for any degree distributions of edge-coupling interdependent networks, the relative sizes of k-core and corona clusters, as well as percolation thresholds are obtained by the derivation of self-consistent equations, and then the phase transition for k-core percolation is analyzed. It is found that when k≥3, with any edge-coupling strengths γA and γB in the networks, the transitions for k-core percolation always occur as first-order discontinuous one. By integrating the theoretical findings with experimental simulation, the significant influence of corona clusters on both the k-core structure and networks robustness is discovered. In view of the 3-core structure upon edge-coupling partially interdependent networks, when γB≥0.67, the robustness of which is gradually weakened with the increase of coupling strengths γA and γB. Nonetheless, significant variations in the edge-coupling strength γ still have limited impact on network robustness. Then a node protection strategy CoronaProtect is put forward, it can be found that with the increase of protection intensity α, the robustness of network is enhanced, while the phase transition of k-core may be changed as well. The effectiveness of the given protection strategy is finally verified through the ER−ER and SF−SF networks. Nevertheless, the given k-core percolation model and protection strategy can not only give help in understanding the hierarchy structure of networks but also provide some guidance in enhancing the resilience of networks against attacks.

Role of clustering in the anomalous properties of supercritical fluids

We propose that the anomalous (non-monotonic) behavior of physical properties of supercritical fluids (SCF) in the Widom delta is attributed to the formation of medium-sized clusters. This hypothesis is experimentally verified for carbon dioxide using both experimental methods and molecular dynamics simulations. From a microscopic point of view, the non-monotonic behavior of the nonlinear refractive index, speed of sound, and Raman scattering efficiency is caused by the formation of quasi-linear clusters of medium size (5–200 molecules per cluster). Within the clusters, the molecule concentration is close to that of the liquid phase, while outside the clusters, it resembles the gas phase, leading to experimentally observed high (∼15 %) density fluctuations. Isolated linear clusters exhibit high second-order hyperpolarizability, resulting in an increase in the molecular contribution to the nonlinear refractive index and the intensity of Raman scattering. The appearance of multiple Widom lines on the pressure–temperature (p-T) diagram, each associated with unique physical properties, arises from the combined effects of cluster-specific and density-related factors. This interplay results in the divergence of Widom lines and the formation of the characteristic feature known as the Widom delta.

Thermodynamics and entropic inference of nanoscale magnetic structures in Gd

A bulk gadolinium (Gd) single crystal exhibits virtually zero remnant magnetization, a common trait among soft uniaxial ferromagnets. This characteristic is reflected in our magnetometry data showing virtually hysteresis free isothermal magnetization loops with large saturation magnetization. The absence of hysteresis allows to model the measured easy axis magnetization as a function of temperature and applied magnetic field, rather than a relation, which permits the application of Maxwell relations from equilibrium thermodynamics. Demagnetization effects broaden the isothermal first-order transition from negative to positive magnetization. By analyzing magnetization data within the coexistence regime, we deduce the isothermal entropy change and the field-induced heat capacity change. Comparing the numerically inferred heat capacity with relaxation calorimetric data confirms the applicability of the Maxwell relation. Analysis of the entropy in the mixed phase region suggests the presence of hitherto unresolved nanoscale magnetic structures in the demagnetized state of Gd. To support this prediction, Monte Carlo simulations of a 3D Ising model with dipolar interactions are performed. Analyzing the cluster size statistics and magnetization from the model provides strong qualitative support of our analytic approach.

Continuity of Short-Time Dynamics Crossing the Liquid-Liquid Phase Separation in Charge-Tuned Protein Solutions.

Liquid-liquid phase separation (LLPS) constitutes a crucial phenomenon in biological self-organization, not only intervening in the formation of membraneless organelles but also triggering pathological protein aggregation, which is a hallmark in neurodegenerative diseases. Employing incoherent quasi-elastic neutron spectroscopy (QENS), we examine the short-time self-diffusion of a model protein undergoing LLPS as a function of phase splitting and temperature to access information on the nanosecond hydrodynamic response to the cluster formation both within and outside the LLPS regime. We investigate the samples as they dissociate into microdroplets of a dense protein phase dispersed in a dilute phase as well as the separated dense and dilute phases obtained from centrifugation. By interpreting the QENS results in terms of the local concentrations in the two phases determined by UV-vis spectroscopy, we hypothesize that the short-time transient protein cluster size distribution is conserved at the transition point while the local volume fractions separate.

Nanodosimetric investigation of the track structure of therapeutic carbon ion radiation part2: detailed simulation

Objectivea previous study reported nanodosimetric measurements of therapeutic-energy carbon ions penetrating simulated tissue. The results are incompatible with the predicted mean energy of the carbon ions in the nanodosimeter and previous experiments with lower energy monoenergetic beams. The purpose of this study is to explore the origin of these discrepancies.Approachdetailed simulations using the Geant4 toolkit were performed to investigate the radiation field in the nanodosimeter and provide input data for track structure simulations, which were performed with a developed version of the PTra code.Main resultsthe Geant4 simulations show that with the narrow-beam geometry employed in the experiment, only a small fraction of the carbon ions traverse the nanodosimeter and their mean energy is between 12% and 30% lower than the values estimated using the SRIM software. Only about one-third or less of these carbon ions hit the trigger detector. The track structure simulations indicate that the observed enhanced ionization cluster sizes are mainly due to coincidences with events in which carbon ions miss the trigger detector. In addition, the discrepancies observed for high absorber thicknesses of carbon ions traversing the target volume could be explained by assuming an increase in thickness or interaction cross-sections in the order of 1%.Significancethe results show that even with strong collimation of the radiation field, future nanodosimetric measurements of clinical carbon ion beams will require large trigger detectors to register all events with carbon ions traversing the nanodosimeter. Energy loss calculations of the primary beam in the absorbers are insufficient and should be replaced by detailed simulations when planning such experiments. Uncertainties of the interaction cross-sections in simulation codes may shift the Bragg peak position.

Impact response of pseudoelastic nitinol

The response of polycrystalline nitinol with solely austenite structure was studied in three series of planar impact tests characterized by loading of the nitinol samples of 0.5–10 mm thickness by 1 mm thick aluminum impactor accelerated up to velocities of about 387, 429, and 567 m/s. In all the tests, the velocities of the free surfaces of the samples were monitored by a laser velocity interferometer. It was found that in all three test series, the amplitude of elastic precursor wave, being initially greater than 4 GPa, rapidly decays with the propagation distance down to ∼2.5 GPa, below which the decay is hindered by atomic clusters of the nanometer size. Based on the part of the velocity histories indicating the shock-induced austenite–martensite transformation, the initial, of about 2.5 × 103 s−1, and the maximum, up to 1 × 105 s−1, rates of the transformation were determined. As well, the impact stress slightly greater than 4 GPa was determined as that required for the onset of the B2 → B19′ transformation under shock loading. The unloading parts of the same velocity histories allowed a rough estimate of the fraction of the shock-transformed martensite and the elucidation of the virtually complete reversibility of the transformation.

Mustard oil mediated synthesis of magic-sized ZnSe nanoclusters

Magic sized ZnSe nanoclusters have applications in a wide range of areas, such as bioimaging, bio-detection techniques, LEDs and solar cells etc. Despite extensive studies done on ZnSe quantum dots (QDs), the technological potential of photonic behaviour of their lower size range clusters is still largely unexplored. We herein present rapid mustered oil mediated synthesis of magic sized ZnSe with their identification as single-family entities by trapping a fixed position doublet in their absorption spectra. Consistent absorption peaks at 304/305 and 318/19 ​nm irrespective of methods employed are presented. The PL spectra show broad emissions between 350 and 550 ​nm dominating blue region of energy offering scope of further tunability. The mustard oil mediated synthesis was performed using thermal, microwave and ultrasound energy. Despite their size domain of about 2 ​nm, their broad XRD pattern have signature of crystalline nature. Mass spectrometry, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are in good support of ZnSe magic size clusters. Typically, blue region CIE coordinates are estimated from PL emission spectra.

Effect of discharge pulse frequency on the microstructure and field-emission performance of CNX films deposited by pulse cathode arc evaporation

CNX thin films were prepared by a pulse cathode arc technique using nitrogen as a dopant at different frequencies. Microstructure, compositions, and morphology of CNX thin films were investigated in the dependence of discharge pulse frequency by Raman spectroscopy, x-ray photoelectric spectroscopy (XPS), atomic force microscopy, scanning electron microscopy, UV–vis spectrophotometry, Hall measurements, and field-emission test. The results of Raman and XPS showed that the Csp2 cluster size of CNX films decreases and then increases and decreases with discharge pulse frequency increasing. The Csp2 cluster size of the films prepared at 9 Hz was the largest. The size of Csp3 content increases for the CNX films at the high discharge pulse frequency. The variation of C–N bonding content with frequency in CNX films is similar to that of Csp2. CNX thin films prepared at a frequency of 9 Hz were improved field-emission properties corresponding to the variation of microstructure parameters (the size and ordering of Csp2 clusters) and compositions (C–N bonds). The excellent field-emission properties, such as a low turn-on electric field of 2.1 V/μm and a high field-emission current density of 517.34 μA/cm2, were obtained.

Hydrodynamic Equations for Space-Inhomogeneous Aggregating Fluids with First-Principle Kinetic Coefficients.

We derive from the first principles new hydrodynamic equations-Smoluchowski-Euler equations for aggregation kinetics in space-inhomogeneous fluids with fluxes. Starting from Boltzmann equations, we obtain microscopic expressions for aggregation rates for clusters of different sizes and observe that they significantly differ from currently used phenomenological rates. Moreover, we show that for a complete description of aggregating systems, novel kinetic coefficients are needed. They share properties of transport and reaction-rate coefficients; for them we report microscopic expressions. For two representative examples-aggregation of particles at sedimentation and aggregation after an explosion-we numerically solve Smoluchowski-Euler equations and perform atomistic simulations by direct simulation Monte Carlo (DSMC). We find that while the new theory agrees well with DSMC results, a noticeable difference is observed for the phenomenological theory. This manifests the unreliability of the currently used phenomenological theory and the need to apply new, first-principle equations.

Fast mass transfer processes of interfering trapped CO2-clusters at reservoir conditions: Experiment and theory

The gas-to-oil ratio (GOR) of a reservoir fluid plays a critical role in optimizing oil recovery and oil production strategies, improving oil recovery efficiency, and predicting reservoir behavior. Understanding the complicated kinetics of multicomponent mass transfer at the pore scale after gas injection into petroleum reservoirs is of great importance for estimating GOR and enhanced oil recovery (EOR). However, to date, there is a significant gap in the fundamental process understanding of the complex mass transfer process at reservoir conditions. Using micro-CT technology, we investigate the time dependence of CO2 mass transfer and cluster growth after high pressure CO2 injection into sedimented porous media (sintered 0.2 mm glass beads).Surprisingly, the CO2 partitioning equilibrium is already reached after 2 h. To the best of our knowledge, such a fast CO2 transport through water-saturated porous media, which cannot be explained by linear diffusion models (time scale 100 days for a diffusion length of 10 cm), has not been reported in the literature before. We proposed a conceptual model that assumes CO2 inflation of interfering gas clusters drives cascading CO2 transport. We verified this conceptual model through a time series of experiments at different initial gas saturation, analyzing in each case the spatial cluster distribution, cluster size distribution, and pore occupancy frequency.Whether CO2 inflation of the gas clusters occurs depends on the critical initial gas saturation, which is about 10%. Our main conclusion is that CO2 migration should be considered as gas phase diffusion cascading along a quasi-percolating cluster, since CO2 inflation leads to a high gas saturation of about 26%, which is close to the percolation threshold. Our experimental results support this physical hypothesis. We show for the first time that CO2 clusters can expand over large pore spaces and thus are close to the critical percolation threshold (mobility threshold). The cluster size distribution can be described by a power distribution with the critical exponent 2.19, i.e., it shows universal scaling.We model the interfering mass transfer processes of neighboring gas clusters with a multi-sphere model. Exploring different scenarios for the dissolution kinetics of an ensemble of interfering gas clusters allow a deeper understanding of the complicated mass transfer kinetics and agree well with experimental cluster analyses at specific times.

Effect of Size-Controlled Nanofluid on Mechanical Properties, Microstructure, and Rheological Behavior of Cement Slurry for Oil Well Cementing.

The optimal design of cement slurry by balancing various cement additives and cement is critical for effective oil well cementation job. However, given adverse circumstances of application, existing additives may not be sufficient to perform suitably in challenging conditions, leading to premature cement hydration, formation of microcracks, and gas channeling pathways. Thus, this study explores the use of a single-step silica nanofluid (NP size: 5-10, 90-100, and 250-300 nm and concentration: 1, 3, and 5 wt %) as an additive and explores its effect on thickening time, fluid loss, and rheological behavior of class G cement slurry at high-pressure and high-temperature (HPHT) conditions (135 °C and 3625 psi). The improvement in thickening time, fluid loss, and rheology of conventional slurry was greater for low NP size than the nanofluid of high NP size: the nanofluid size, e.g., 5-10 nm, and concentration (1 wt %) were found to accelerate the thickening time by 30-40% while reducing fluid loss from 38 mL (no silica, slurry CS) to 30 mL (with silica, slurry C1). The rheological behavior was studied via shear (viscosity) and dynamic (elastic moduli, G') modes to evaluate the viscosity, hysteresis, and elastic response of slurry with and without nanofluid. The inclusion of nanofluid slightly reduced the slurry viscosity; however, all slurries exhibited shear thinning with superior fitting with the power law model. As compared to slurry CS, hysteresis of slurry C1 was least dependent on shear deformation, and thus, it showed that it almost matched viscosity profiles during loading and unloading cycles. The addition of silica was found to maintain the original properties of cement slurry, establishing that cement had not agglomerated, and no sedimentation was observed even at shear rates of 1000 s-1. The results of this study greatly promote the use of silica nanofluid as an important additive in class G cement for cementation operations, which is unlikely with a two-step nanofluid where nanoparticles are expensive, and upon mixing, they tend to agglomerate and make large size clusters.

Fast Collective Hydrogen-Bond Dynamics in Hexafluoroisopropanol Related to its Chemical Activity.

Using fluorinated mono-alcohols, in particular hexafluoro-isopropanol (HFIP), as a solvent can enhance chemical reaction rates in a spectacular manner. Previous work has shown evidence that this enhancement is related to the hydrogen-bond structure of these liquids. Here, we investigate the hydrogen-bond dynamics of HFIP and compare it to that of its non-fluorinated analog, isopropanol. Ultrafast infrared spectroscopy experiments show that the dynamics of individual hydrogen-bonds is about twice as slow in HFIP as in isopropanol. Surprisingly, from dielectric spectroscopy we find the opposite behavior for the dynamics of hydrogen-bonded clusters: collective rearrangements are 3 times faster in HFIP than in isopropanol. This difference indicates that the hydrogen-bonded clusters in HFIP are smaller than in isopropanol. The differences in cluster size can be traced to changes in the hydrogen-bond donor and acceptor strengths upon fluorination. The smaller cluster size can boost reaction rates in HFIP by increasing the concentration of reactive, terminal OH-groups of the clusters, whereas the fast collective dynamics can increase the rate of formation of hydrogen-bonds with the reactants. The longer lifetime of the individual hydrogen-bonds in HFIP can enhance the stability of the hydrogen-bonded clusters, and so increase the probability of reactant-solvent hydrogen-bonding.

Transcriptomic analysis reveals role of lncRNA LOC100257036 to regulate AGAMOUS during cluster compactness of Vitis vinifera cv. sistan yaghooti

Yaghooti grape, as the earliest grape variety in Iran, is considered as more resistant to heat, drought, and salinity than other cultivars. Cluster compactness is regarded as an inappropriate feature for the productivity of Yaghooti grape as a critical commercial and nutritional product. In plants, lncRNAs play a critical role in regulating biological processes related to growth and development. However, the potential role of lncRNAs was not assessed in cluster compactness. Totally, 1549 lncRNAs were identified by RNA-Seq data analysis in three steps of cluster formation, berry formation, and final cluster size after a thorough screening process. In addition, 229 lncRNAs were differentially expressed in the cluster development steps. Based on the functional analysis, lncRNAs are related to AG and MYB, bHLH, LBD, NAC, and WRKY TFs. Further, the target genes enrichment analysis revealed a relationship between lncRNAs with grape growth and development, as well as resistance to abiotic stresses such as heat and drought, plant defense against pathogens, and early grapes ripening. The study identified four lncRNAs as precursors of miRNAs, predicting that 112 other lncRNAs could potentially be targeted by 166 miRNAs. The results provide new insights into the regulatory functions of lncRNAs in Yaghooti grape to improve overall understanding of the molecular mechanisms related to grape compactness.

Study on grain refinement of AlB2 structure in aluminium alloys

ABSTRACT Aiming at the problem of unclear grain refinement mechanism in aluminium alloys, Al n B n (n = 2–12) clusters and Al–3B alloy were studied by density functional theory methods. The results show that as the cluster size increased, B atoms self-aggregated, and Al atoms surrounded the surface of the clusters. In addition, Al and B atoms formed stable AlB2 triangular structures. The average binding energy gradually increased with increasing clusters size, which indicated that the clusters structures were gradually stable. Range of n = 2–11, the Al9B9 cluster showed the most stable structure. Electronic properties and interatomic interactions calculation results suggested that there was a minimum electrostatic potential point on the surface of the B atom, and the B atom in AlB2 may be the adsorption site of α-Al. The ab initio molecular dynamics simulations results of the Al–3B alloy showed that Al and B generated the AlB2 structure in situ, and Al atoms nucleated and grew on the AlB2 surface. These results can be used to understand the grain refinement mechanism of the Al–B intermediate alloy.

Investigation of coarse-graining parameters for super-grid LEM closure applied to LES of practical bluff-body flames

Large Eddy Simulation (LES) coupled with the Linear Eddy Model (LEM) provides a robust method for studying turbulent combustion, but it is computationally expensive due to the need for highly resolved sub-grid LEM domains. These domains simulate sub-grid stirring through stochastic rearrangements of scalar fields, while large-scale transport is modelled using a Lagrangian ‘splicing’ scheme. To address the computational cost of LES-LEM, a super-grid (SG) framework for LEM closure was developed by the authors (Comb. Theor. Model. 28, 2024), which uses coarse-graining, on-the-fly chemistry tabulation and a presumed PDF approach to reconstruct thermochemical fields at LES resolution. This study applies SG-LEM to a challenging setup, Case 1 of the Volvo Validation Rig, which involves a bluff-body-stabilised turbulent premixed propane-air flame, as a stress test to identify limitations that were not revealed by the previous application, in particular that of the coarse-graining parameters used to generate the super-grid. The intent is to yield a more realistically constrained assessment of the current capabilities of the method, and insight into possible ways for improving it. Four simulations were conducted using three SG cluster sizes. The finest resolution was tested with a global 2-step mechanism, showing good agreement with experimental data for temperature and velocity, particularly near the bluff body. The two larger cluster sizes used a 66-step skeletal mechanism for more detailed chemical closure but led to unphysical quenching due to splicing inaccuracies. To mitigate these issues, two novel additions were introduced: an intra-cluster-stirring routine and a method to control SG cluster shapes to reduce numerical dissipation. These methods improved flame stability with coarser SG clusters and more detailed mechanisms. Comparison with experiments showed good agreement for temperature and velocity, though elevated CO levels were observed in the recirculation region. Potential methods for further improving SG-LEM's capabilities are discussed.