Initial Conditions Research Articles

Assessment of the Sensitivity of the Mean Climate Simulation over West Africa to Planetary Boundary Layer Parameterization Using RegCM5 Regional Climate Model

This study evaluates the performance of two planetary boundary parameterizations in simulating the mean climate of West Africa using the Regional Climate Model version 5 (RegCM5). These planetary boundary parameterizations are the Holtslag scheme and the University of Washington scheme. Two sets of three one-year simulations were carried out at 25 km horizontal resolution with three different initial conditions. The first set of simulations used the Holtslag scheme (hereafter referred to as Hol), while the second used the University of Washington (UW) scheme (hereafter referred to as UW). The results displayed in this study are an average of the three simulations. During the JJAS rainy season, with respect to GPCP, both models overestimated total rainfall in the orographic regions. The UW experiment represented total rainfall fairly well compared to its counterpart, Hol. Both models reproduced convective rainfall well, with a relatively weak dry bias over the Guinean coast subregion. Globally, UW performed better than Hol in simulating precipitation. The pattern of near-surface temperature in both models was well reproduced with a higher bias with Hol than with UW. Indeed, the UW scheme led to a cooling effect owing to the reduction in eddy heat diffusivity in the lower troposphere contributing to reduce the bias. As a consequence, the height of the planetary boundary layer (PBL) was best simulated using the UW scheme but was underestimated compared to ERA5, while using the Hol scheme failed to capture the height of the PBL. This is coherent with the distribution of total cloud cover, which was better simulated with the UW scheme compared to the Hol scheme. This study shows that use of both planetary boundary parameterizations leads to a good simulation of most of the climatological characteristics of the West African region. Nevertheless, use of the UW scheme contributes to a better performance than use of the Hol scheme, and the differentiation between the two schemes is significant along the Guinea Coast and in orographic regions. In these topographically complex regions, UW appears to be more appropriate than Hol. This study emphasizes the importance of planetary boundary parameterizations for accurately simulating climate variables and for improving climate forecasts and projections in West Africa.

An analytical approach to engineer multistability in the oscillatory response of a pulse-driven ReRAM

A nonlinear system, exhibiting a unique asymptotic behaviour, while being continuously subject to a stimulus from a certain class, is said to suffer from fading memory. This interesting phenomenon was first uncovered in a non-volatile tantalum oxide-based memristor from Hewlett Packard Labs back in 2016 out of a deep numerical investigation of a predictive mathematical description, known as the Strachan model, later corroborated by experimental validation. It was then found out that fading memory is ubiquitous in non-volatile resistance switching memories. A nonlinear system may however also exhibit a local form of fading memory, in case, under an excitation from a given family, it may approach one of a number of distinct attractors, depending upon the initial condition. A recent bifurcation study of the Strachan model revealed how, under specific train stimuli, composed of two square pulses of opposite polarity per cycle, the simplest form of local fading memory affects the transient dynamics of the aforementioned Resistive Random Access Memory cell, which, would asymptotically act as a bistable oscillator. In this manuscript we propose an analytical methodology, based on the application of analysis tools from Nonlinear System Theory to the Strachan model, to craft the properties of a generalised pulse train stimulus in such a way to induce the emergence of complex local fading memory effects in the nano-device, which would consequently display an interesting tuneable multistable oscillatory response, around desired resistance states. The last part of the manuscript discusses a case study, shedding light on a potential application of the local history erase effects, induced in the device via pulse train stimulation, for compensating the unwanted yet unavoidable drifts in its resistance state under power off conditions.

Analytical solution to non-isothermal pore-pressure evolution in hydrating minefill

Anomalous rises in minefill pressure during deposition shutdown have been increasingly reported in recent field investigations, raising growing concerns over contemporary underground tailings disposal. While constrained backfill expansion during hydration-heat release has been invoked to rationalize such perplexing observations, a benchmark for understanding the complex minefill response to thermal loading is still lacking. A novel analytical procedure is thus proposed in this study to characterize the non-isothermal evolution of pore pressure in cemented backfill hydrating in undrained adiabatic settings. By constructing a suitable variable system and selecting a proper auxiliary parameter for calculation, the proposed strategy based on canonical thermo-poroelasticity could enable straightforward implementation and has shown excellent compliance with computational and experimental results. The analytical results suggest that because higher temperature could stimulate cement hydration while enhancing simultaneously fluid expansivity, the pore pressure would decline initially with the rising curing temperature and then revert to increase after a critical threshold. Moreover, our investigation has shown that increasing binder usage is not always conducive to pore-pressure dissipation, as the payoff can be also hinged strongly upon the initial thermal condition. These findings could better elucidate the intriguing control of coupled multiphysics processes on backfill behaviour, and can also serve benchmarking purposes for sophisticated computational procedures.

Study of the effect of salt deposition on production capacity and storage capacity in underground gas storage

Underground gas storage (UGS) is the most economical and effective means to guarantee stable gas supply. During gas production process, the evaporation of formation water leads to the increase of water content in the gas, and the salinity of the remaining formation water increases. This work applied numerical simulation to analyze the effect of salt deposition on flowing bottomhole pressure, production capacity and storage capacity. The simulation results show that the minimum and maximum pressure of UGS is more likely to be reached during multi-cycle production under the conditions of salt deposition. Under the initial water condition, reservoir drying can improve the gas storage capacity. At the end of the tenth cycle, the storage capacity increases by 1.4%. It is concluded that the study on the impact of formation water evaporation on storage capacity is helpful for the prevention and control of salt formation water in UGS with high salinity.

Robustness of hydrometeorological extremes in surrogated seasonal forecasts

AbstractWater and disaster risk management require accurate information about hydrometeorological extremes. However, estimation of rare events using extreme value analysis is hampered by short observational records, with large resulting uncertainties. Here, we present a surrogate world setup that makes use of data samples from meteorological and hydrological seasonal re‐forecasts to explore extremes for long return periods. The surrogate timeseries allow us to pool the re‐forecasts into 1000‐year‐long timeseries. We can then calculate return values of extremes and explore how they are affected by the size of sub‐samples as method for estimating the uncertainty. The approach relies on the fact that probabilistic seasonal re‐forecasts, initialized with perturbed initial conditions, have limited predictive skill with increasing lead time. At long lead times re‐forecasts will diverge into independent samples. The meteorological seasonal re‐forecasts are taken from the SEAS5 system, and hydrological re‐forecasts are generated with the E‐HYPE process‐based model for the pan‐European domain. Extreme value analysis is applied to annual maxima of precipitation and streamflow for return periods of 100 years. The analysis clearly demonstrates the large uncertainty in long return period estimates with typical available samples of only few decades. The uncertainty is somewhat reduced for 100‐year samples, but several 100 years seem to be necessary to have robust estimates. The bootstrap with replacement approach is applied to shorter timeseries, and is shown to well reproduce the uncertainty range of the longer samples. However, the main estimate of the return value can be significantly offset. Although the method is model based, with the associated uncertainties and bias compared to the real world, the surrogate approach is likely useful to explore rare and compounding extremes.

Detailed chemical composition of the globular cluster Sextans A GC-1 on the outskirts of the Local Group

The chemical composition of globular clusters (GCs) across the Local Group provides information on chemical abundance trends. Studying GCs in isolated systems in particular provides us with important initial conditions plausibly unperturbed by mergers and tidal forces from the large Local Group spirals. We present a detailed chemical abundance analysis of Sextans A GC-1. The host galaxy, Sextans A, is a low-surface-brightness dwarf irregular galaxy located on the edge of the Local Group. We derive the dynamical mass of the GC together with the mass-to-light ratio and the abundances of the alpha , Fe-peak, and heavy elements. Abundance ratios were determined from the analysis of an optical integrated-light spectrum of Sextans A GC-1, obtained with UVES on the VLT. We apply non-local thermodynamic equilibrium (NLTE) corrections to Mg, Ca, Ti, Fe, and Ni. The GC appears to be younger and more metal-poor than the majority of the GCs of the Milky Way, with an age of 8.6pm 2.7 Gyr and $ Fe/H dex. The calculated dynamical mass is dyn odot $, which results in an atypically high value of the mass-to-light ratio, 4.35pm 1.40 M$_ odot $/L$_ V odot $. Sextans A GC-1 has varying alpha elements -- the Mg abundance is extremely low, Ca and Ti are solar-scaled or mildly enhanced, and Si is enhanced. The measured values are $ Mg/Fe Ca/Fe Ti/Fe and $ Si/Fe which makes the mean alpha abundance (excluding Mg) to be enhanced $ <Si,Ca,Ti>/Fe NLTE The Fe-peak elements are consistent with scaled-solar or slightly enhanced abundances: $ Cr/Fe Mn/Fe Sc/Fe and $ Ni/Fe The heavy elements measured are Ba, Cu, Zn, and Eu. Ba and Cu have sub-solar abundance ratios ($ Ba/Fe and $ Cu/Fe <-0.343$), while Zn and Eu are consistent with their upper limits being solar-scaled and enhanced, $ Zn/Fe <+0.171$ and $ Eu/Fe The composition of Sextans A GC-1 resembles the overall pattern and behaviour of GCs in the Local Group. The anomalous values are the mass-to-light ratio and the depleted abundance of Mg. There is no definite explanation for such an extreme abundance value. Variations in the initial mass function or the presence of an intermediate-mass black hole might explain the high mass-to-light ratio value.

Numerical simulations of a hydrogen-air pre-detonator for detonation engines

In recent years, heat release associated with the detonation phenomenon is considered a very efficient process. Pressure gain combustors are being developed with detonation waves as the driving force. In this scenario, study of detonation waves has become very important. Deflagration-to-Detonation transition (DDT) is one of the ways used to initiate detonation in the combustors. An attempt has been made in this paper to study the DDT in a tube with obstacles using OPENFOAM. A 2-dimensional rectangular section of a tube containing obstacles filled with stoichiometric hydrogen-air mixtures at different initial conditions have been studied. The effect of changes in the length of the tube, number of obstacles, blockage ratios and initial pressure of the reactants on the detonation wave properties have been studied using numerical simulation based on ddtfoam software. The motivation for this study is to design a pre-detonator for a rotating detonation engine (RDE). In order to make it compatible with the RDE and the test facility, it has been proposed to carry out simulations using shorter lengths of the DDT tube. The number of obstacles has been selected appropriately to obtain detonation at shorter lengths of the tube of the order of 1.5 m, 1.0 m & 0.5 m. As the objective has been to obtain design data for the prototype, the finer details of DDT are not being discussed in this paper.

Advanced Optimal Control Problem and Numerical Method for its Solving

The advanced statement of the optimal control problem is presented. The difference between the extended setting of the problem and the classical one is that the model of the control object consists of two subsystems, a reference model, which generates an optimal motion path and a dynamic model of the control object with a system for stabilizing movement along the optimal trajectory. In the problem, it is necessary to find a program control function whose argument is time and a stabilization system function whose argument is the deviation of the state vector of the control object from the optimal program trajectory. The task has many initial conditions, one of which is used in the search for software control, and the rest for the search for a stabilization system. The control quality criterion is defined as the sum of the original quality criterion for all specified initial conditions. The procedure for trans forming the classical setting of the optimal control problem to an extended setting based on the refinement of the problem for its practical implementation is presented. To solve the extended optimal control problem, a universal numerical method is proposed based on a piecemeal linear approximation of the control function using evolutionary algorithms and symbol regression methods for structurally parametric optimization of the stabilization system function. An example of solving an extended optimal control problem for spatial motion by a quadcopter, which should conduct reconnaissance of a given territory in a minimum time, is given.

Design and analysis of ELM-based predefined time sliding mode adaptive controller for PMLM position control under physical constraints

Achieving accurate position tracking for robotics and industrial servo systems is an extremely challenging task, particularly when dealing with control saturation, parameter perturbation, and external disturbance. To address these challenges, a predefined time convergent sliding mode adaptive controller (PTCSMAC) has been proposed for a permanent magnet linear motor (PMLM). A novel sliding mode surface (SMS) with predefined time convergence PDTC has been constructed, which ensures that the error converges to zero within the prescribed time. The system not only meets the expected performance standards but also has a uniformly bounded motor speed. The trajectory tracking error in SMS is proven to converge to zero within the predefined time. This predefined time stability of the closed-loop system has been demonstrated by using the Lyapunov stability criterion with PDTC. The convergence time (CT) can be arbitrarily set, and the upper bound of it is not affected by the initial value and control parameters of the system. A new updated version of extreme learning machine (ELM) is introduced to approximate the uncertain part of the system based on PDTC. The ELM is also provided with the hyperbolic tangent function to estimate the saturation constraint. This is done by converting the function into a linear function concerning the unconstrained control input variable. Then, based on established stability, a novel sliding mode adaptive controller (PTCSMAC) with predefined time convergence is designed. The convergence time (CT) of the controller is unaffected by the initial conditions as well as the control parameters. The rigorous numerical simulations on the PMLM model with complex disturbances verify the strong robustness and high-precision tracking characteristic of the proposed control law.

Modeling the Light Curve of HD 222925's Progenitor Kilonova

The leading theory for heavy element nucleosynthesis is that a majority of isotopes heavier than iron are formed in neutron star mergers (NSMs), visible through the kilonovae that proceed them. In this work, we derive the potential kilonova light curve associated with the elemental abundances of the “gold standard” metal-poor star HD 222925, which is thought to be enriched by a single NSM. Previous work explores which initial kilonova conditions best match the elemental abundances in HD 222925 and finds two main solutions: either the ejecta is highly constrained, or the underlying nuclear microphysics model is incomplete. We construct the light curves for these two cases in hopes of using kilonova to break this degeneracy. We find that our merger models produce light curves that are observationally too alike to robustly distinguish between the two valid models, offering little hope for constraining kilonova ejecta or the behavior of neutron-rich nuclei.

Incorporating temporal information during feature engineering bolsters emulation of spatio-temporal emergence.

Emergent biological dynamics derive from the evolution of lower-level spatial and temporal processes. A long-standing challenge for scientists and engineers is identifying simple low-level rules that give rise to complex higher-level dynamics. High-resolution biological data acquisition enables this identification and has evolved at a rapid pace for both experimental and computational approaches. Simultaneously harnessing the resolution and managing the expense of emerging technologies-e.g. live cell imaging, scRNAseq, agent-based models-requires a deeper understanding of how spatial and temporal axes impact biological systems. Effective emulation is a promising solution to manage the expense of increasingly complex high-resolution computational models. In this research, we focus on the emulation of a tumor microenvironment agent-based model to examine the relationship between spatial and temporal environment features, and emergent tumor properties. Despite significant feature engineering, we find limited predictive capacity of tumor properties from initial system representations. However, incorporating temporal information derived from intermediate simulation states dramatically improves the predictive performance of machine learning models. We train a deep-learning emulator on intermediate simulation states and observe promising enhancements over emulators trained solely on initial conditions. Our results underscore the importance of incorporating temporal information in the evaluation of spatio-temporal emergent behavior. Nevertheless, the emulators exhibit inconsistent performance, suggesting that the underlying model characterizes unique cell populations dynamics that are not easily replaced. All source codes for the agent-based model, emulation, and analyses are publicly available at the corresponding DOIs: 10.5281/zenodo.10622155, 10.5281/zenodo.10611675, 10.5281/zenodo.10621244, respectively.

Reconstructing the baryonic acoustic oscillations in the presence of photo-z uncertainties

ABSTRACT The reconstruction method has been widely employed to improve the baryon acoustic oscillations (BAO) measurement in spectroscopic survey data analysis. In this study, we explore the reconstruction of the BAO signals in the realm of photometric data. By adapting the Zel’dovich reconstruction technique, we develop a formalism to reconstruct the transverse BAO in the presence of photo-z uncertainties under the plane-parallel approximation. We access the performance of the BAO reconstruction through comoving N-body simulations. The transverse reconstruction potential can be derived by solving a 2D potential equation, with the surface density and the radial potential contribution acting as the source terms. The solution is predominantly determined by the surface density. As is evident in dense samples, such as the matter field, the transverse BAO reconstruction can enhance both the strength of the BAO signals and their cross correlation with the initial conditions. At z = 0, the cross-correlation is increased by a factor of 1.2 at $k_\perp = 0.2 \, \mathrm{Mpc}^{-1}h$ and 1.4 at $k_\perp = 0.3 \, \mathrm{Mpc}^{-1}h$, respectively. We contrast the 2D potential results with the 3D Poisson equation solution, wherein we directly solve the potential equation using the position in photo-z space, and find good agreement. Additionally, we examine the impact of various conditions, such as the smoothing scales and the level of photo-z uncertainties, on the reconstruction results. We envision the straightforward application of this method to survey data.

Enhanced flow variability and morphological changes through individual wood placements on a gravel bed

To design and evaluate river restoration projects with wood, it is crucial to understand how the placement of wood will alter flow and bed morphology. This information is still missing. To address this, flume experiments were conducted with a single log placed on a mobile bed with a uniform grain size. The effect of log diameter, log orientation to the flow, and log length on flow variability and bed morphology was studied for various initial flow conditions. Even a single log increased flow variability, herein defined as spatial variability in both velocity and turbulent kinetic energy. For each log placed at the channel center, the logs generated a symmetric scour pattern alongside and downstream of the log due to increased bed shear and turbulence generated by the log. A steady, adjusted cross-section was reached at the cessation of erosion, which occurred when the bed stress decreased below the critical shear velocity. Logs with larger diameter tended to erode more deeply, so that the final, adjusted cross-section was similar for different log dimensions. Changes in bed topography affected wake characteristics. Logs with small changes in bed topography generated longer zones of reduced velocity, which can increase the residence time of organic matter or nutrients in the wake region. Logs with big changes in bed topography created the deepest and longest scour holes, which may locally reduce stream temperature and improve fish habitat during summer.

EXTINGUISHING TIME OF OIL PRODUCT TANK FIRES WITH SELF-EXPANDING GAS-AEROSOL-FILLED FOAM

EXTINGUISHING TIME OF OIL PRODUCT TANK FIRES WITH SELF-EXPANDING GAS-AEROSOL-FILLED FOAM

ANALISIS PERUBAHAN URBAN HEAT ISLAND DAN PENGARUHNYA TERHADAP INDEKS KENYAMANAN KOTA BANJARBARU

The Banjarbaru administrative status has changed from an Administrative City to a City, and in 2022 become the Provincial Capital. Population growth and infrastructure/building development due to these changes may affect environmental changes. A significant increase in air temperature against its normal due to environmental changes can trigger climate change. Urban Heat Island (UHI) is a phenomenon recognized by the higher temperature conditions in urban areas compared to surrounding areas. UHI identification is known by calculating the difference in Land Surface Temperature (LST) values using remote sensing (satellite data). An increase in the value of LST in an area can trigger the appearance of UHI and make the environment less comfortable. The LST value is also related to population, vegetation, residential areas, and built-up land. Thermal Humidity Index (THI) is an index used to determine comfort level based on temperature and humidity conditions. This study aims to analyze spatiotemporal changes in UHI phenomena in the Banjarbaru area during three administrative status periods (1998 - 2022) and its effect on the comfortable index. This study uses Landsat satellite data (consist Visible, Near Infrared, and Thermal Bands) and Relative Humidity (RH) from 2 weather stations in Banjarbaru. The result shows that the distribution of UHI in the Banjarbaru City area increases around industrial areas, settlements, government centers, and along arterial roads that are open land without trees. In general, the Banjarbaru area experienced an increase in the comfort index. Initial conditions belonging to the comfortable and less comfortable classes changed to become less comfortable to uncomfortable, especially in the North Banjarbaru sub-district and around Syamsudin Noor Airport ( Landasan Ulin sub-district).

Fixed-time nonsingular terminal sliding mode control for trajectory tracking of uncertain robot manipulators

Fixed-time nonsingular terminal sliding mode control for trajectory tracking of uncertain robot manipulators

Model order reduction based on Laguerre orthogonal polynomials for parabolic equation constrained optimal control problems

In this paper, two model order reduction methods based on Laguerre orthogonal polynomials for parabolic equation constrained optimal control problems are studied. The spatial discrete scheme of the cost function subject to a parabolic equation is obtained by Galerkin approximation, and then the coupled ordinary differential equations of the optimal original state and adjoint state with initial value and final value conditions are obtained by Pontryagin's minimum principle. For this original system, we propose two kinds of model order reduction methods based on the differential recurrence formula and integral recurrence formula of Laguerre orthogonal polynomials, respectively, and they are totally different from these existing researches on model order reduction only for initial value problems. Furthermore, we prove the coefficient-matching properties of the outputs between the reduced system and the original system. Finally, two numerical examples are given to verify the feasibility of the proposed methods.

Efficient conversion of cane molasses into Tremella fuciformis polysaccharides with enhanced bioactivity through repeated batch culture

Tremella fuciformis polysaccharide (TFPS) is a natural mushroom mucopolysaccharide widely used in health foods, medical care, cosmetic and surgical materials. In this study, we developed an efficient strategy for the repeated batch production of highly bioactive TFPS from the agro-industrial residue cane molasses. Cane molasses contained 39.92 % sucrose (w/w), 6.36 % fructose and 3.53 % glucose, all of which could be utilized by T. fuciformis spores, whereas, the TFPS production efficiency only reached 0.74 g/L/d. Corn cobs proved to be the best immobilized carrier that could tightly absorb spores and significantly shorten the fermentation lag period. The average yield of TFPS in eight repeated batch culture was 5.52 g/L with a production efficiency of 2.04 g/L/d. The average fermentation cycle after optimization was reduced by 61.61 % compared with the initial conditions. Compared to glucose as a carbon source, cane molasses significantly increased the proportion of low-molecular-weight TFPS (TFPS-2) in total polysaccharides from 3.54 % to 17.25 % (w/w). Moreover, TFPS-2 exhibited potent antioxidant capacity against four free radicals (O2−, ABTS+, OH, and DPPH). In conclusion, this study lays the foundation for the efficient conversion of cane molasses and production of TFPS with high bioactivity.

104 Maternal pre- and post-partum supplementation of Bacillus-based DFM enhanced cow and calf performance

Abstract This study evaluated the effects of maternal supplementation of Bacillus-based direct-fed microbials (DFM) on physiology and growth performance of Bos indicus-influenced cow-calf pairs. On d 0 (~139 d before expected calving date), 72 fall-calving, Brangus crossbred beef heifers (25 to 37.5% Bos indicus; 20 to 22 mo of age) pregnant with their first offspring were stratified by their initial body weight (BW; 431 ± 31 kg) and body condition score (BCS; 6.0 ± 0.36; scale 1 to 9), and randomly allocated into 1 of 12 bahiagrass pastures (1 ha and 6 heifers per pasture). Treatments were randomly assigned to pastures (6 pastures per treatment) and consisted of heifers supplemented with 1 kg/d of soybean hulls dry matter (DM) added (BAC) or not (CON) with a Bacillus-based DFM mixture (BovacillusTM; Chr. Hansen A/S, Hørsholm, Denmark) from d 0 to 242 (139 ± 4 d prepartum to 104 ± 4 d postpartum). Calves were weaned on d 242 (96 ± 30 d of age) and then allocated into 1 of 16 drylot pens and limit-fed the same concentrate at 3.25% of BW until d 319. Maternal treatment effects were not detected (P ≥ 0.29) for herbage allowance, forage nutritive value, and heifer activity on pasture. Heifer BCS on d 39 and 63 tended (P ≤ 0.09) to be greater, whereas heifer BCS on d 91 was greater (P = 0.01) for BAC vs. CON heifers and did not differ (P ≥ 0.20) between treatments on d 179 and 242. Plasma concentrations of glucose did not differ from d 0 to 63 (P ≥ 0.14) but were greater (P = 0.005) on d 179 and tended (P = 0.09) to be greater on d 242 for BAC vs. CON heifers. First offspring BW at birth, ADG from birth to early weaning, and BW weaning did not differ (P ≥ 0.19), but BW at drylot exit (d 319) was greater (P = 0.05) for BAC vs. CON calves. Maternal treatment effects were not detected (P ≥ 0.42) for calf serum concentrations of IgG at birth, and post-vaccination plasma concentrations of glucose, cortisol and haptoglobin. However, serum titers against bovine respiratory syncytial virus (BRSV) were greater (P = 0.04) for BAC vs. CON calves on d 287, whereas seroconversion against parainfluenza 3 virus (PI-3) was greater (P < 0.01) for BAC vs. CON calves on d 271. Thus, maternal supplementation of Bacillus-based DFM increased prepartum BCS gain and postpartum plasma concentrations of glucose of heifers and led to positive carryover effects on post-weaning BW gain and some indicators of humoral immune response to vaccination in their first offspring.

Observation of non-Hermitian skin effect in thermal diffusion

The paradigm shift of Hermitian systems into the non-Hermitian regime profoundly modifies inherent property of the topological systems, leading to various unprecedented effects such as the non-Hermitian skin effect (NHSE). In the past decade, the NHSE has been demonstrated in quantum, optical and acoustic systems. Beside those wave systems, the NHSE in diffusive systems has not yet been observed, despite recent abundant advances in the study of topological thermal diffusion. In this work, we design a thermal diffusion lattice based on a modified Su-Schrieffer-Heeger model and demonstrate the diffusive NHSE. In the proposed model, the asymmetric temperature field coupling inside each unit cell can be judiciously realized by appropriate configurations of structural parameters. We find that the temperature fields trend to concentrate toward the target boundary which is robust against initial excitation conditions. We thus experimentally demonstrated the NHSE in thermal diffusion and verified its robustness against various defects. Our work provides a platform for exploration of non-Hermitian physics in the diffusive systems, which has important applications in efficient heat collection, highly sensitive thermal sensing and others.