Energy Of Fragments Research Articles

Fractal Behavior of Size Distribution and Specific Surface Area of Blasting Fragments

The shape characteristics of blasting fragments are important for analyzing the blasting fragmentation mechanism and evaluating the fragmentation energy efficiency. In this study, through field blasting experiments and morphological parameter measurements, fractal theory was employed to reveal the fractal characteristics of rock blasting fragmentation. Using the fragmentation fractal dimension, the probability of rock blasting fragmentation was analyzed, and a predictive formula for the specific surface area (SSA) of blasting fragments was established. For fragments, the fractal dimensions of the particle size distribution calculated using different characteristic sizes were less than 2.0. When the fragment size distribution had dual fractal characteristics, significant differences were observed in the scale-free interval and fragmentation fractal dimension. Within the large scale-free interval, the fragmentation fractal dimension was mostly greater than 2.3, whereas within the small scale-free interval, it tended to be less than 2.0. The rock fragmentation process typically consisted of two or three breakage levels, with a similarity ratio of 0.5 and an average fragmentation probability ranging from 0.44 to 0.71. The predicted SSA of the blasting fragments closely matched the measured values. The findings provide valuable insights into the mechanism of rock blasting fragmentation and the calculation of fragmentation energy consumption.

Half‐Sandwich, Bent‐Sandwich and Triple‐Decker Molybdenum Complexes of S2N2 – Fluxionality and Metal‐Metal Bond

AbstractThe instability of the π‐complexes of electron‐rich inorganic aromatics with transition metal fragments, contrary to their conventional aromatic analogues, was investigated by taking the four‐membered 6π‐electron S2N2. Our theoretical investigation based on fragment molecular orbitals and Energy Decomposition Analysis with Natural Orbitals for Chemical Valence (EDA‐NOCV) on the bonding nature of different types of π‐complexes of S2N2 viz. half‐sandwich, bent‐sandwich and triple‐decker type complexes with molybdenum fragment reveals that S2N2 can potentially act as a six π‐electron donor. However, due to the lower energy π* MOs the π‐back donation from metal fragment is stronger than the π‐donation, which might lead to weaking of the overall ring structure and low dissociation energy. The dissociation energy for dissociation of one S2N2 ring increases with the increasing number of S2N2 in the complex. The smaller size of the ring leads to fluxional behaviour in order to attain orbital compatibility between the π‐MOs and the metal orbitals. Also, the triple decker complex depicts an unsymmetric middle deck, where the middle S2N2 ring has been fragmented into two SN units along with a Mo−Mo bond. The higher dissociation energy of triple‐decker complexes can be corroborated well with the report of an isoelectronic triple‐decker complex [Mo2Te12]6+.

Optimization of the matching relationship between the stemming length and minimum burden in cut blasting of large-diameter long-hole stopes

Cut blasting, in which new surfaces and relief space for subsequent blasting are created, is one of the most critical steps in the establishment of large-diameter long-hole (LDL) stopes. To reduce the damage to the chamber roof caused by stemming recoil and improve the rock breaking effect, 15 groups of small-scale model tests with minimum burdens of 3, 4, 5, 6, and 7 cm and stemming lengths of 0, 2, 4, 5, 6, and 7 cm were designed to optimize the matching relationship between the stemming length and minimum burden. First, through the model tests, values were obtained for ten evaluation indexes related to the total mass of fragments, crate size, fragment size, fragmentation energy consumption, and stemming recoil area. Then, the normal cloud combination weighting method was used to combine six subjective and objective weighting methods, and combined weights were obtained. Finally, the test schemes were optimized according to the Euclidean distance and similarity. The test results showed that the best blasting scheme involves a burden of 5 cm and a stemming length of 5 cm, followed by that involving a burden of 4 cm and a stemming length of 4 cm, and the optimal stemming length is approximately equal to the minimum burden. A field test of LDL stope cut blasting was conducted, with a stemming length of 2.2 m and a minimum burden of 2.2 m in the boreholes. The highly satisfactory field blasting effect indicates that the stemming length and minimum burden are reasonable.

Total kinetic energy release in the fast neutron induced fission of actinide nuclei

The total kinetic energy release and fission mass distributions for the fast neutron (En = 3–100 MeV) induced fission of 232Th, 233U, 235U, 237Np, 239Pu, 240Pu, and 242Pu have been measured using the LANSCE facility. The neutron energies were deduced from time-of- flight measurements. The fission fragments were detected using Si PIN diode detectors, giving us the fragment energies. The actinide targets were made by vapor deposition leading to high-quality targets, that were thin and uniform with reduced impurities. Corrections were made to the data for pulse height defect and the fragment energy loss in the target and its backing. The TKE distributions were Gaussian in shape and their mean value as a function of incoming neutron energy could be fitted with second order polynomials. In the case of 233U and 235U, our measurements agree with prior work. Our measurements for 232Th are unique. Our data agree with Viola scaling. The constant position of the heavy mass peak is interpreted as being due to the influence of the N = 88 and Z = 50 shells. The GEF model predictions agree with the data in general as do the CGMF model predictions.

Spatio-temporal fragmentation-aware time-varying service provisioning in computing power networks based on model-assisted reinforcement learning

Widespread application of AI with high computing requirements has promoted the rapid development of cloud and edge computing. Ubiquitous computing resources need to be interconnected through high-performance IP and optical networks. Computing power networks (CPNs) have been studied as an IP/optical cross-layer architecture to provide on-demand computing services. The service provisioning in CPNs can be modeled as a virtual optical network embedding problem; however, the time-varying characteristics of service requirements increase the complexity. In particular, there can be stranded computing or bandwidth resources that are isolated in the spatio-temporal dimension and therefore difficult for other requests to utilize. This phenomenon is referred to as spatio-temporal resource fragmentation, which will lead to inefficient use of resources and higher energy consumption. To meet the time-varying requirements and achieve an energy-efficient CPN, in this paper, we first analyze the main reason for spatio-temporal resource fragmentation and excess energy consumption in cross-layer CPNs, which is the mismatched embedding scheme and the inappropriate scheduling order. Therefore, an auxiliary-graph-model-assisted edge-featured graph-attention-network-enabled DRL algorithm, DeepDefrag, is studied to solve the problem. Its core highlight is co-optimizing the scheduling and embedding of time-varying virtual networks along with the awareness of resource fragmentation. In addition, an integer linear programming algorithm is developed to determine the performance bounds. We validate DeepDefrag through a series of ablation studies and comparison algorithms under different numbers of requests. The results show that DeepDefrag can achieve >26.4% lower energy consumption for CPNs compared with the DRL-based baseline. Moreover, it is shown to generalize well across requests and networks.

Fragment-based models for dissociation of strong acids in water: Electrostatic embedding minimizes the dependence on the fragmentation schemes.

Fragmentation methods such as MIM (Molecules-in-Molecules) provide a route to accurately model large systems and have been successful in predicting their structures, energies, and spectroscopic properties. However, their use is often limited to systems at equilibrium due to the inherent complications in the choice of fragments in systems away from equilibrium. Furthermore, the presence of charges resulting from any heterolytic bond breaking may increase the fragmentation error. We have previously suggested EE-MIM (Electrostatically Embedded Molecules-In-Molecules) as a method to mitigate the errors resulting from the missing long-range interactions in molecular clusters in equilibrium. Here, we show that the same method can be applied to improve the performance of MIM to solve the longstanding problem of dependency of the fragmentation energy error on the choice of the fragmentation scheme. We chose four widely used acid dissociation reactions (HCl, HClO4, HNO3, and H2SO4) as test cases due to their importance in chemical processes and complex reaction potential energy surfaces. Electrostatic embedding improves the performance at both one and two-layer MIM as shown by lower EE-MIM1 and EE-MIM2 errors. The EE-MIM errors are also demonstrated to be less dependent on the choice of the fragmentation scheme by analyzing the variation in fragmentation energy at the points with more than one possible fragmentation scheme (points where the fragmentation scheme changes). EE-MIM2 with M06-2X as the low-level resulted in a variation of less than 1 kcal/mol for all the cases and 1 kJ/mol for all but three cases, rendering our method fragmentation scheme-independent for acid dissociation processes.

Modelling and mechanical characteristics of PDC cutter-rock interaction by combining mixed fragmentation modes with dynamic rock strength

Polycrystalline diamond compact (PDC) bit is one of the most widely used drill bits for improving the rate of penetration in deep oil and gas well and geothermal well. However, the dynamic rock fragmentation mechanics characteristics of PDC bits are still unclearly. A coupled fragmentation mechanics model of PDC cutter-rock interaction is established by combining the mixed fragmentation modes with dynamic strength. The coupling influence laws of cutter angle, cutting depth, dynamic strength ratio, breaking modes on the horizontal force coefficient (HFC), vertical force coefficient (VFC) and specific energy are analyzed. The model of this paper can optimize cutter inclination angle, cutting depth and minimum specific energy. With the increase of the cutter inclination angle, the dynamic VFC changes into two modes. The definition of the dynamic modes depends on the dynamic strength ratio. As the cutting angle increases, the cutting force increases. The cutting force increases nonlinearly with increasing cutting depth. The specific energy of rock fragmentation increases nonlinearly with increasing cutting depth. With the increase of dynamic strength, the specific energy of rock fragmentation increases nonlinearly. When the input-energy increases, the rate of penetration response is divided into three stages. The results have important guiding significance for the PDC bit design and drilling parameters optimization to increase the rate of penetration and the efficiency of exploration and development.

Experiment Study of Stemming Length and Stemming Material Impact on Rock Fragmentation and Dynamic Strain

Stemming length and stemming materials are crucial factors in blasting design, which affect the sustainability of mining. This study investigates the influence of stemming length and stemming material on rock fragmentation, stemming recoil, and surface strain response through 15 small-scale model blasting tests. The results indicate that when using clay as a stemming material, increasing the stemming length facilitates rock fragmentation and reduces the stemming recoil area. The strain measurements show that both tensile and compressive strain peaks on the blasting crater surface increase with the growth of stemming length, while the strain peaks on the upper surface decrease. A comparative analysis of different stemming materials reveals that clay performs the best, exhibiting the highest total weight of fragments, blasting crater size, and fragmentation energy utilization. Strain results indicate that clay stemming generates more significant strain peaks and higher strain loading rates on the blasting crater surface, favoring a more concentrated application of explosive energy on the crater surface and improving rock fragmentation. Sand + clay stemming yields fragments more concentrated in medium-sized particles than clay stemming. If the blasting goal is to increase the utilization efficiency of explosive energy and reduce the hazards of stemming recoil, it is recommended to use clay stemming. In addition, if uniform fragmentation is desired (reducing large and fine particles), a combination of sand + clay stemming can be used. These findings have practical implications for optimizing blasting design and engineering applications.

Rockfalls, fragmentation, and dust clouds: analysis of the 2017 Pousset event (Northern Italy)

The process and dynamics of rock fragmentation during the collapse of rockfalls and rock avalanches is a poorly developed topic. The most severe fragmentation often leads to the formation of a rock dust that rises to form a cloud suspended in the air. The understanding of fragmentation processes is hampered by the environmental disturbances that alter the dust cloud deposit shortly after deposition. Here, we study the fragmentation of the October 2017 Pousset rockfall, detached from a NNE facing steep bedrock wall in the permafrost zone, that involved 8,300m3 of metamorphic rock and fell about 800 m. The collapse generated large boulders which rolled downslope and a thick and large dust cloud. The source and deposit were investigated, and dust cloud material was sampled at different locations to reconstruct an exponential thickness distribution and perform grain size characterization. The fragmentation energy was estimated by integrating the spectrum of the grains assuming that the fragmentation energy is proportional to the generated area. The fragmentation energy was found to be about 0.4% of the initial potential energy. Most probable fragmentation points and block deposition areas were evaluated and positioned by means of the HyStone 3D rockfall simulator. Furthermore, we calculated the flow rate of the suspended powder generated by the fragmentation process and compared the results with observations available for the evolution of the phenomenon and the collected samples. The Pousset event, in its relatively simple dynamics, may be a good testing ground to address the current theories of rockfall and rock avalanche fragmentation and dust cloud behavior.

Total Kinetic Energy of Fission Fragments based on Fission Product Data

Total kinetic energy (TKE) is the physical quantity that must be acquired during a nuclear fission reaction. This energy is used for various purposes, primarily to determine the spectrum of the second proton. This spectrum is advantageous in the design of nuclear reactors. Various techniques for calculating TKE, from microscopic to macroscopic, have been carried out, from statistical to quantum reviews. This whole technique is solely for obtaining TKE accurately. This paper will review the TKE calculation based on the fission products' experimental results. This fission product data can be in the form of raw experimental data or evaluated data. The calculations are carried out within a macroscopic and statistical review framework. The macroscopic view is a liquid drop model, while the statistics use the random number technique. Because the liquid drop model and the random number technique are very standard, this paper does not review them.

Trimethylplatinum(IV) Complexes for MOCVD Applications: A Physicochemical Study

The structure of trimethylplatinum(IV) iodide [(CH3)3PtI]4 (I) (CIF file CCDC no. 22330007) is refined. The structure of the synthesized for the first time trimethylplatinum(IV) complex with tridentate N,N,O-iminoketonate [(CH3)3Pt(C9H17N2O)] (II) is determined by X-ray diffraction (XRD) (CIF file CCDC no. 22330008). The purity of the isolated phases is confirmed by elemental analysis and IR and NMR spectroscopy. The thermal behavior of complex II is studied by thermogravimetry. The energies of ionization and fragmentation of the molecules of complex II leading to the formation of the most stable fragment [(CH3)3Pt]+ are estimated by quantum-chemical calculations. Complex II is tested in the MOCVD processes. The Pt films with the pronounced (111) texture and particle sizes about 100 nm are prepared on Si plates in the presence of oxygen.

Explosion of high pressure hydrogen tank in fire: Mechanism, criterion, and consequence assessment

This study published experimental data on the catastrophic rupture consequences of high-pressure hydrogen storage tanks in fire environments. It made up for the lack of actual explosion data for verification of the traditional theoretical prediction models and numerical simulations. To reveal the mechanism of high-pressure tank explosion and corresponding characteristics of hydrogen explosion, the fireball parameters, fragment characteristics, and blast wave attenuation patterns resulting from tank rupture were analyzed. The results indicated that the hazard of hydrogen storage tank explosion was coupled with the combined contribution of physical and chemical explosion energies. The failure pressure of a 6.8 L – 30 MPa tank under fire conditions decreased by 60.3 % compared to that at room temperature. Following tank explosion, the duration of hydrogen-air deflagration was only about 2 s, and the maximum diameter of the fireball was nearly 4.48 m. A portion of the mechanical energy generated by tank explosion was converted into the kinetic energy of projectile fragments, with the farthest discovered fragment distance reaching 46.0 m. Additionally, the measured peak overpressure decreased from 875.33 kPa to 7.52 kPa at distances ranging from 2 m to 15 m from the explosion source. To evaluate blast wave overpressure in high-pressure hydrogen tanks for engineering applications, a standardized and generalized procedure was innovatively proposed, and its effectiveness was validated by experimental data. Furthermore, the hazardous distances defined by the peak overpressure were utilized to delineate risk zones. The distances of 61.6 m and 17.3 m from the explosion source were identified as zones without injury to human and without damage to structures, respectively. The proposed methodology and the results of the experiments were of practical importance for ensuring the safety of high-pressure hydrogen storage systems in various applications.

Dynamic properties and fragmentation fractal characteristics of water-saturated reef limestone concrete under impact loading

Reef limestone was used as a coarse–fine aggregate to prepare concrete with a strength class of C30. The mechanism of influences of water-saturated state on dynamic compressive strength, energy dissipation, and macroscopic and microscopic failure modes of reef limestone concrete was studied, and the relationships between fractal dimension and loading rate, fragmentation characteristics, and energy dissipation were discussed. The results indicated that the dynamic compressive strength of reef limestone concrete presents power function growth with increasing loading rate, the free water reduces the degree of cementation among particles and weakens the quasi-static state and dynamic mechanical properties of reef limestone concrete. Meanwhile, under the same loading rate, water-saturated reef limestone concrete demonstrates a stronger energy absorption effect and a greater energy dissipation density, and the energy dissipation density is linearly correlated with the dynamic compressive strength. In addition, the irregular shape and porous structure of reef limestone aggregate particles effectively enhances the friction strengths between the aggregates and cement slurry, causing most of the dynamic cracks in reef limestone concrete to occur in the cement-sand slurry and aggregates themselves. Finally, the results also show that the fractal dimension of the fragments of reef limestone concrete increases linearly with increases in the loading rate and fragmentation energy dissipation density. At approximately the same loading rate, the fractal dimension of dry specimens was larger, and when the fractal dimensions in the two states were similar, the energy consumed per unit mass water-saturated specimen exceeds that of dry specimens.

Structure and stability of Mo-doped Cun (n = 1–12) clusters: DFT calculations

The thermodynamic and chemical stability of CunMo (n = 1–12) clusters are evaluated by density functional theory (DFT) calculations. The most stable structures are obtained by using the SCG (systematic growth algorithm) and corroborated by simulated annealing. The lowest-energy structures of CunMo clusters are planar and quasiplanar for n = 3–7, while icosahedral-like structures for n = 8–12. The relative stability of the clusters is further analyzed through the average binding energy, the fragmentation energy and second-order energy differences. The results of EB shows that doping with Mo slightly reduces the stability of small clusters with n = 1–7, however, for n = 8 onward, the doped clusters become more stable due to the formation of the icosahedral structure at Cu12Mo. The results show that Cu4Mo, Cu7Mo, Cu9Mo and Cu12Mo, are more stable than the neighbor clusters. In addition, the doped clusters show higher HOMO–LUMO gaps and total spin magnetic moments compared to pure Cun clusters. The IR spectra of the clusters are provided.

Damage and failure characteristics of coal and surrounding rock under shaped blasting

The high crustal stress in deep coal mining undermines the efficiency and safety of blasting operations conducted to increase gas permeability in the coal seam. Therefore, in this study, theoretical research, computer-based numerical simulations, and experiments were conducted to investigate the damage and fracture characteristics of a coal body and surrounding rock subjected to shaped blasting. ANSYS LS-DYNA was employed for numerical simulations to understand how a shaped jet is formed and how damage occurs in shaped blasting. A model of crack evolution under the influence of detonation gases that is based on fracture mechanics theory was constructed to analyze the mechanism underlying the directional propagation of detonation cracks in shaped blasting. In the conducted experiments, shaped blasting resulted in the creation of an oval-shaped fragmentation area, which was evidence that the shaped cartridge limited the loss of energy in fragmentation, allowed detonation cracks to evolve further in the specimen, and caused the formation of a main crack that propagated in the direction along which energy was concentrated (i.e., directional damage). Compared with ordinary blasting, shaped blasting facilitated more efficient blast energy use and reduced undesirable blast disturbance to the surrounding rock by 58% according to the computed tomography image of resistivity. The results of this study provide valuable insights on safe and efficient coal production.

Physicochemical Characteristics for Fen (n = 2–10) Cluster by Density Functional Theory

The In this work, we present a theoretical study on the equilibrium geometry and the energetic, electronic and magnetic properties of Fen (n = 2–10) based on the use of density functional theory (DFT). The results are obtained using Both Generalized Gradient Approximation according to the scheme described by Perdew-Burke-Ernzerhof (GGA-PBE). More stable structures obtained compared to other isomers have not been previously found. It is shown by the results calculated as the calculated fragmentation energy, and the second-order energy difference that Fen (n = 7,8,9) clusters are more stable than the other cluster sizes. The calculated magnetic properties of the most stable clusters display varying magnetic torque between values 3.00 μB and 3.35 μB, except for the Fe10 cluster, which takes the upper value 3.38 μB. These results are very important for experimental experts who are active in designing new nanocatalysis systems in the physical and chemical fields.

Penetration enhanced behaviour of reactive fragment impacting medium-thickness plate

The medium-thickness plate penetration enhanced behavior of coupled kinetic energy and chemical energy of reactive fragment was investigated. A series of penetration experiments were conducted. After the experiments, the High-speed photography images and blackening at front plate were compared. The results show that the enhancement behavior of reactive fragment penetrating is related to the intensity of deflagration at front plate. Division of deflagration zones of reactive fragment impacting at front plate is proposed, combine dynamic model of reactive fragment penetrating medium-thickness plate, reveal the enhancement mechanism of reactive fragment penetrating medium-thickness plate below ballistic limit velocity.

Research on Theoretical Model of Ceramic/PE Composite Protection for Projectile

In order to predict the ballistic limit of ceramic/ UHMWPE composite protection, a theoretical model of ceramic/UHMWPE composite protection for projectile was established based on A-T model and fiber energy dissipation model. In the ballistic impact process, the fragments will experience ceramic dwell, ceramic fragmentation and fiber layer energy dissipation. The theoretical model obtained is compared with the experimental and simulation results. The results show that the residual velocity obtained by the theoretical model is in good agreement with the experimental and simulation results, and it can be applied to ceramic/UHMWPE composite protection of projectile penetration to a certain extent.

Fragments-in-fragments method for efficient and reliable estimates of individual hydrogen bond energies in large molecular clusters.

The knowledge of individual hydrogen bond (HB) strength in molecular clusters is indispensable to get insights into the bulk properties of condensed systems. Recently, we have developed the molecular tailoring approach based (MTA-based) method for the estimation of individual HB energy in molecular clusters. However, the direct use of this MTA-based method to large molecular clusters becomes progressively difficult with the increase in the size of a cluster. To overcome this caveat, herein, we propose the use of linear scaling method (such as the original MTA method) for the estimation of single-point (SP) energies of large-sized parent molecular cluster and their respective fragments. Because the fragments of the MTA-based method, for the estimation of HB energy, are further fragmented, this proposed strategy is called as Fragments-in-Fragments (Frags-in-Frags) method. The SP energies of fragments and parent cluster calculated by the Frags-in-Frags approach were utilized to estimate the individual HB energy. The estimated individual HB energies, in various molecular clusters, by Frags-in-Frags method are found to be in excellent linear agreement with their MTA-based counterparts (R2 = 0.9975 of 348 data points). The difference being less than 0.5 kcal/mol in most of the cases. Furthermore, RMSD is 0.43 kcal/mol, MAE is 0.33 kcal/mol, and the standard deviation is 0.44 kcal/mol. Importantly, the Frags-in-Frags method not only enables the reliable estimation of HB energy in large molecular clusters but also requires less computational time and can be possible even with off-the-shelf hardware.

Fission dynamics of excited compound nuclei in a wide range of fissile parameters produced in O16,18+X reactions within a stochastic approach

A stochastic approach based on four-dimensional Langevin equations has been used to simulate the fission dynamics of the excited compound nuclei $^{256}\mathrm{Fm}, ^{254}\mathrm{Fm}, ^{224}\mathrm{Th}, ^{215}\mathrm{Fr}, ^{213}\mathrm{Fr}, ^{200}\mathrm{Pb}, ^{187}\mathrm{Ir}, ^{172}\mathrm{Yb}, ^{170}\mathrm{Yb}, ^{162}\mathrm{Yb}, ^{142}\mathrm{Ce}$, and $^{125}\mathrm{Cs}$ produced in ${}^{16,18}\mathrm{O}+X$ reactions with projectile energies 158.8 and 288 MeV. The effect of nuclear dissipation was investigated in the dynamical simulation of fission process of these nuclei. The average prescission neutron multiplicity, the fission time, the average total kinetic energy of fission fragments, the mass and energy distribution of fission fragments, and the variation of the prescission neutron multiplicity with total kinetic energy of fission fragments have been calculated for these nuclei. The dynamical calculations have taken into account not only three shape collective coordinates introduced on the basis of the ``funny hills'' shape parameters but also orientation degree of freedom (spin about the symmetry axis), and in the dynamical calculations dissipation generated through the chaos-weighted wall and window friction formula and also the sum of the chaos-weighted wall and window friction formula with the two-body nuclear friction. Furthermore, the effect of dissipation coefficient of $K, {\ensuremath{\gamma}}_{K}$, were also considered in the dynamical calculations. Comparison of the theoretical results with the experimental data shows that the experimental data for compound nuclei produced with the projectile energy 158.8 MeV can be reproduced satisfactorily with the results of calculations by using the chaos-weighted wall and window friction formula, although the results of calculations of the average prescission neutron multiplicity, the fission time, and the variation of the pre-scission neutron multiplicity with total kinetic energy of fission fragments lie somewhat below the experimental data for heavy nuclei produced in reactions with projectile energy ${E}_{\mathrm{lab}}=158.8\phantom{\rule{0.28em}{0ex}}\mathrm{MeV}$ and also for compound nuclei produced with the projectile energy 288 MeV. It was also shown that for reproducing experimental data for heavy nuclei produced in reactions with projectile energy ${E}_{\mathrm{lab}}=158.8\phantom{\rule{0.16em}{0ex}}\mathrm{MeV}$ and also for nuclei produced with projectile energy ${E}_{\mathrm{lab}}=288\phantom{\rule{0.16em}{0ex}}\mathrm{MeV}$ is suitable to use the sum of the chaos-weighted wall and window friction formula with the two-body nuclear friction in the Langevin equations. In other words, for simulations of fission dynamics of nuclei at high excitation energies and also for heavy nuclei it is suitable to use the sum of the chaos-weighted wall and window friction formula with the two-body nuclear friction in the Langevin equations.