Huang Model Research Articles

Experimental study evaluating the performance of thermal conductivity prediction models for air–water saturated weathered sandstone heritage

As a critical parameter, thermal conductivity directly determines the heat transfer and temperature variation within rocks, which can lead to mechanical damage and chemical corrosion. Consequently, understanding the thermal conductivity of stone heritage is vital for assessing their deterioration mechanisms and developing effective conservation strategies. This study obtained sandstone samples from the Yungang Grottoes and subjected them to freeze–thaw cycle experiments to generate weathered sandstone samples. Subsequently, the thermal conductivity of these samples was measured under both dry and water-saturated state using the transient plane source method. To analyze the relationship between air–water saturation, porosity, and thermal conductivity, a saturation influence coefficient was introduced. Thereafter, the effectiveness and applicability of 13 commonly used thermal conductivity mixing law prediction models were evaluated based on experimental data. The results suggested that the influence of water saturation on the thermal conductivity of rocks varies with porosity, and water saturation significantly enhances the thermal conductivity of weathered sandstone. Among the 13 common models, the Geometric mean model was found to be more accurate than other models, with superior performance in both dry (MAE, RMSE, MAPE are 0.148, 0.214, 5.59% respectively) and water-saturated (MAE, RMSE, MAPE are 0.244, 0.170, 8.4% respectively) state. The Albert model demonstrates a good fit in the dry state, whereas the Walsh model (with maximum effect), Ribaud model, and Huang model also exhibit good fitting efficacy in the water-saturated state. This study provides a solid foundation for better predicting the thermal conductivity of weathered stone heritage and developing effective preventive conservation strategies.

Three-pressure prediction method of jointing well-seismic data in JT1 well area of Sichuan Basin in China

With the high yield of many wells represented by Well JT1 in the Maokou Formation, has catalyzed a surge in exploration activities along the platform margin facies of the Maokou Formation in central Sichuan and further showed the significant exploration potential of the Maokou Formation in the northern slope. However, the fracture cave body of the Maokou Formation exhibits a high degree of development, strong longitudinal and horizontal heterogeneity, large formation pressure differences, and drilling events such as gas kicks and lost circulation occur frequently, which seriously affects the efficient implementation of drilling. Understanding the spatial distribution of the three-pressure in the formation can help better deal with and solve the above problems. Therefore, in order to help the safe, high-quality and rapid drilling of the Maokou Formation in the study area, and enhance the efficiency of oil and gas development, this paper explores the research on the prediction method of the three-pressure of jointing well-seismic data based on the geomechanical experimental data and the actual drilling data. In the process of prediction of pore pressure, this study found that the pore pressure and formation velocity in the study area have an exponential relationship. In order to enhance the applicability of the Filippone’s method in the study area and improve the prediction accuracy of pore pressure, the linear relationship between pore pressure and formation velocity in the Filippone’s method is modified to an exponential relationship, and a pore pressure prediction model suitable for the work area was established. Based on the Mohr–Coulomb criterion and Huang's model, the prediction models of collapse pressure and fracture pressure applicable to the study area were established, respectively. Then, the elastic parameters were obtained through pre-stack inversion, and the three-pressure bodies were calculated based on the elastic parameter bodies. The results indicate that: (1) The three-pressure prediction method of the jointing well-seismic data in this paper can predict the formation's longitudinal and transverse pressure anomaly zones in advance. (2) The Maokou Formation in the study area is characterized by abnormally high pressure, to balance the pressure of the high-ground formation, high-density drilling fluid is necessary. (3) The prediction results of three-pressure in this paper are highly consistent with the actual drilling engineering events, which verifies the reliability of the three-pressure prediction results presented in this study. The results of the study can provide a basis for decision-making in drilling geological design, such as the determination of drilling fluid density, the evaluation of borehole stability and other engineering problems that require support from three-pressure data.

Modeling the growth behavior of Salmonella spp. in grated carrots inoculated with different inoculum levels stored at various temperatures

AbstractThe consumption of fresh and fresh‐cut fruits and vegetables, such as carrots, has increased for the last decades for a healthy life and an adequate diet, but concerns regarding the microbial safety of them have been raised. The present study was conducted to develop predictive models for Salmonella spp. in grated carrots. The results showed that Salmonella spp. did not display growth at 5°C, but it grew in grated carrots at other temperatures (10, 15, 20, 25, and 37°C) for both inoculum levels. Also, the inoculum levels affected the growth of this pathogen in grated carrots when the storage temperatures ranged from 15 to 25°C. The theoretical minimum temperatures calculated using the Huang model were 3.48 and 5.79°C for inoculum levels of 101 and 102 CFU/g, respectively. The primary and secondary models performed well in terms of agreement between experimental and estimated values. Furthermore, compared to the Ratkowsky model, the theoretical minimum temperature was given a more reasonable value using the Huang model. The models developed in the present study will be a useful input for future quantitative microbial risk assessment to appraise the proliferation of Salmonella spp. in grated carrots throughout the production process, storage, and distribution.

Construction of warfarin population pharmacokinetics and pharmacodynamics model in Han population based on Bayesian method

The purpose of this paper is to study the genetic polymorphisms of related gene loci (CYP2C9*3, VKORC1-1639G > A) based on demographic and clinical factors, and use the maximum a posterior Bayesian method to construct a warfarin individualized dose prediction model in line with the Chinese Han population. Finally, the built model is compared and analyzed with the widely used models at home and abroad. In this study, a total of 5467 INR measurements are collected from 646 eligible subjects in our hospital, and the maximum a posterior Bayesian method is used to construct a warfarin dose prediction that conforms to the Chinese Han population on the basis of the Hamberg model. The model is verified and compared with foreign models. This study finds that body weight and concomitant use of amiodarone have a significant effect on the anticoagulant effect of warfarin. The model can provide an effective basis for individualized and rational dosing of warfarin in Han population more accurately. In the performance of comparison with different warfarin dose prediction models, the new model has the highest prediction accuracy, and the prediction percentage is as high as 72.56%. The dose predicted by the Huang model is the closest to the actual dose of warfarin. The population pharmacokinetics and pharmacodynamics model established in this study can better reflect the distribution characteristics of INR values after warfarin administration in the Han population, and performs better than the models reported in the literature.

Characterisation of the surface growth of Mucor circinelloides in cheese agar media using predictive mathematical models

The main objective of this work was to characterise the mycelial growth of Mucor circinelloides, one of the fungal contaminants that appear frequently in the artisan cheese production environment. The study uses primary Baranyi and Huang models to compare their parameters and predict M. circinelloides on cheese-based medium (CBA) under diverse environmental conditions (temperature range from 6 to 37 °C and 0 and 1 % NaCl concentration). However, the Baranyi model consistently estimated longer lag phases and higher surface growth rates (sgr) than the Huang model; both models showed adequate best-fit performance (exactly with the mean coefficient of determination R2 = (0.993 ± 0.020 × 10−1). The groups of primary growth parameters were analysed against temperature using the cardinal model (CM) with the following main outputs. The optimal surface growth rates (sgropt) on CBA were 6.8 and 6.5 mm/d calculated with the Baranyi and Huang models, respectively. They were reduced by approximately 46 % on the surface of the agar medium when 1 % NaCl was added. Topt was estimated in a very narrow range of 32.1–32.5 °C from both primary sgr data sets (0 % and 1 % NaCl). Similarly, Tmax values of 37.2 °C and 37.3 °C were estimated for the Baranyi and Huang models, respectively; however, they decreased at 2 °C in CBA with 1 % NaCl (Tmax = 35.1 °C). The application of CM for sgr provided an estimation of the parameter Tmin with negative values that are considered only as a theoretical output. The results provide insight into the modelling and prediction of fungi growth as a function of time and salt concentration, including the times to detect visible mycelial growth of Mucor circinelloides. The mere quantification of this phenomenon can be useful for practice. Adjusting the frequency of the cheese surface washing step with a salt solution at the early stage of ripening properly can prevent the growth of not only fast fungal growers.

Solitary fibrous tumor: Can the new Huang risk stratification system for orbital tumors improve prognostic accuracy in other tumor locations?

Solitary fibrous tumors (SFTs) are known for their heterogeneous morphology, characterized by a variety of cell shapes and different growth patterns. They can also arise in various anatomical locations, most commonly in extremities and deep soft tissues. Despite this diversity in morphology and location, all SFTs share a common molecular signature involving the NAB2::STAT6 gene fusion. Due to their unpredictable clinical behavior, establishing prognostic factors is crucial. This study aims to evaluate an orbital risk stratification system (RSS) proposed by Huang et al. for use in extraorbital SFTs using a database of 97 cases. The Huang model takes into consideration tumor size, mitotic figures, Ki-67 index, and dominant constituent cell (DCC) as key variables. Survival analysis confirmed the model's predictive value, with higher-risk scores being associated with poorer outcomes. However, in contrast to the orbital SFTs studied by Huang et al., our study did not find a correlation between tumor size and recurrence in extraorbital cases. While the Huang model performs slightly better than other RSS, it falls short on achieving statistical significance in distinguishing recurrence risk groups in extraorbital locations. In conclusion, this study validates the Huang RSS for use in extraorbital SFTs and underscores the importance of considering DCC, mitotic count, and Ki-67 together. However, we found that including tumor size in this model did not improve prognostic significance in extraorbital SFTs. Despite the benefits of this additional RSS, vigilant monitoring remains essential, even in cases classified as low-risk due to the inherent unpredictability of SFT clinical outcomes.

Lattice vibration modes and electron-phonon interactions in monolayer vs. bilayer of transition metal dichalcogenides.

Transition metal dichalcogenides are at the center of intense scientific activity due to their promising applications, as well as the growing interest in basic research related to their electronic and dielectric properties. The layered structure of single-(ML) and two-layer (2ML) samples presents exciting features for light-matter interaction, electron transport, and electronic and optoelectronic applications. Lattice vibrations and electron-phonon interactions are essential for studying the above mentioned topics. Phonon spectra in ML and 2ML of MoX2 and WX2 (X = S, Se, and Te) families are studied using first principles calculations. A comprehensive analysis of the two-dimensional optical-phonon dispersion laws is performed, and the results illustrate the main differences between ML and 2ML for each considered semiconductor. Taking advantage of ab initio calculations, a generalization of the phenomenological Born-Huang dielectric model for long-wavelength vibrational modes around the Γ-point of the Brillouin zone (BZ) in 2ML structures is implemented. Explicit expressions are derived for the optical phonon dispersion of in-plane and out-of-plane normal modes. The set of characteristic parameters describing each long-wavelength optical branch is resolved from a direct comparison with the exact dispersion laws provided using the first principles calculations. The long-range electron-phonon Pekar-Fröhlich (PF) interaction and intra-valley electron scattering rates at the K-point of the BZ via E' (LO) and Eul longitudinal optical oscillations are examined for the ML and 2ML structures, respectively. The non-local macroscopic screening and the coupling between the in-plane electric field and longitudinal optical mechanical oscillation, profoundly affect the PF Hamiltonian and the carrier inverse relaxation time.

Investigating the Sorption Isotherms and Hysteresis of a Round Perforated Brick Using Newly Developed Models

This article deals with the hygrothermal behavior of round perforated brick including hysteresis effects. It aims at examining the effect of temperature on sorption isotherms and hysteresis of this product, reducing the energy consumption of the buildings, reinforcing the constructional economy and the inhabitant’s comfort as well as offering a hygrothermal description of this product that has never been previously investigated. To achieve this, we have carried out an experimental study to determine the sorption isotherms and the hysteresis in five different temperatures (10, 23, 30, 40, and 50 °C). Twelve equations have been tested against the experimental isotherms in order to find the optimal one. After that, three models were tested in order to develop a personal model; the latter explains the real effect of the hysteresis phenomenon on hygrothermal behavior of the studied product. To validate the mathematical model, two methods were applied to calculate the isosteric heat. The obtained results revealed a significant influence of the increase in temperature on the hygrothermal behavior in which a decrease in the equivalent water content was found. Moreover, the developed experimental model is based on Oswin’s model describing the dependence of temperature on the sorption characteristics of round perforated bricks. Furthermore, the Huang model was found to be the best compared with the other models with a regression factor (R2) of 0.990. The validation of the results using the isosteric heat parameter has confirmed that the suggested models demonstrated a perfect presentation of the sorption isotherms and the hysteresis phenomenon of the round perforated brick.

Development of a predictive model for the growth of Staphylococcus aureus in costeño chesee covered with active film

Staphylococcus aureus is a foodborne bacterium frequently isolated from cheeses, and it is responsible for causing food poisoning. The purpose of this study was to develop a secondary model to assess the growth of S. aureus in costeño cheese packaged with an active film. Costeño cheese samples were inoculated with S. aureusand covered with an active film made from an aqueous extract of Schinopsis balansae. Subsequently, the cheese samples were stored at temperatures of 6, 12, 18, and 21 °C. The Huang model was applied to the experimental data of S. aureus to determine growth parameters. The maximum growth rate (μmax) was then used as a function of temperature to create the secondary model using a polynomial equation. The results indicate that the application of the active film of S. aureus had a significant influence on growth parameters of S. aureus such as μmax, lag-phase (λ), and maximum cell population (Ymax) in Costeño cheese. The validation process included measuring the indices: accuracy factor (Af ), bias factor (Bf ), and root mean square error (RMSE). The secondary model exhibited Af and Bf factors close to one, suggesting that the polynomial models are viable to predict S. aureus growth in cheese packaged with active film, considering temperature and storage time.

The damage mechanism of the metastable β-titanium alloy Ti5321 with specific microtexture using synchrotron X-ray microtomography

In order to investigate damage mechanism of metastable β-titanium alloy Ti5321 with bimodal microstructure and specific microtexture, in situ tensile test was performed facilitating with synchrotron X-ray microtomography. The damage evolution of metastable β-titanium alloy Ti5321 can be predicted in three dimensions by proper micromechanics-based modelling methods, the Rice and Tracey model and Huang model. Through comparisons of the Rice and Tracey model and Huang model validated using the values of stress triaxiality calculated from experimental data and Finite Element (FE) simulations, the prediction accuracy of growth rates of voids can be enhanced. The results also show that the void growth is strongly related to microtexture of α plates. It is found that the growth path of largest voids is along α plates which have their c-axes with similar inclination angle of ∼45° from rolling direction (RD). Electron backscatter diffraction (EBSD) was also used to reveal the damage mechanism. This result is important enlightenment for study of damage mechanism of metastable β-titanium alloys.

Estimation of Hidden Logits Using Several Randomized Response Techniques

In survey sampling, we aspire to obtain sound and consistent responses, which are not achieved while dealing with sensitive issues. Frequently, respondents give elusive responses to sensitive questions, so we employ randomized response techniques that facilitate finding an appropriate proportion of socially sensitive characteristics. In the present study, we proposed a hidden logit estimation method using Huang, Warner, and Mangat’s randomized response techniques. This study depicts that the estimates become closer to the standard logits as the values of p increase. We found that the hidden logit estimates obtained by the Huang randomized response technique were nearer to the parametric values, in contrast to the other existing techniques, and we demonstrate an increase in accuracy as well. The simulation-based AIC and SIC values are used to assess model performance. We found that the Huang model is the best model for the proposed hidden logit method. This paper contributes towards the application of logistic models in the case of sensitive or socially stigmatized issues.

Primary Growth Models Investigation of Pseudomonas nitroreducens Growth on Octylphenol Polyethoxylates

This study evaluated the degradation of octylphenol polyethoxylates by Pseudomonas nitrore-ducens TX1 using secondary kinetics analysis. Nonlinear kinetic regression was employed through the utilization of curve-fitting software in order to fit the digitized growth degradation data. A comprehensive analysis was conducted using various statistical metrics including root-mean-square error (RMSE), adjusted coefficient of determination (adjR2), bias factor (BF), accu-racy factor (AF), corrected AICc (Akaike Information Criterion), Bayesian Information Criterion (BIC), and Hannan-Quinn information criterion (HQC). The accuracy and statistical analysis of the kinetic models used showed that only the Huang, Baranyi Roborts, modified Gompertz, Bu-chanan-3-phase, modified Richards and Von Bertalanffy model fit the data, with modified Logis-tics having the best model with low RMSE and AICc values, highest adjusted R2 values, and Bias Factor and Accuracy Factor values closest to unity. The calculated values for the modified Logis-tics constant maximum growth rate (m), maximum growth value (A) and lag period (l), were 0.179 (h-1), 2.199 and 13.015 h, respectively. Growth curve of the bacterium on varying concen-trations of this compound can then be modelled using this model and the maximum growth rate value can be utilized for secondary modelling works further revealing important parameters.

Mathematical Modeling of Molybdenum Blue Production from Bacillus sp. Strain Khayat

In the long run, bioremediation is the utmost cost-effective way, particularly at low concentrations while other methods like physical or chemical procedures would be ineffective, for the elimination of heavy metals and organic pollutants. The process of reducing molybdenum (sodium molybdate) with an oxidation state of (VI) to molybdenum blue (oxidation state from V to VI) serves as a form of detoxification. Important characteristics, such as specific reduction rate, theoretical reduction maximum, and the lag duration of reduction, can be shown by mathematical modeling of the reduction process. While natural logarithm transformation is a common linearization approach, it is not precise and can only provide a rough estimate of the most important single measurable parameter; the specific growth rate. In this study, for the first time, values for the aforementioned parameters or constants were calculated using a wide range of models, including the logistic, Gompertz, Richards, Schnute, Baranyi-Roberts, Buchanan three-phase, von Bertalanffy and most recently, the Huang model. Based on statistical tests including root-mean-square error (RMSE), bias factor (BF), adjusted coefficient of determination (adjR2), accuracy factor (AF), and corrected Akaike information criterion (AICc), the logistics model was found to be the best model for representing the Mo-blue production curve of Bacillus sp. strain khayat. The fitting technique resulted in the calculation of three parameters: specific reduction rate (h-1), Lag period (h), and maximum Mo-blue production (nmole Mo-blue). In this study, we utilize a mathematical technique to determine the reduction parameters for Mo-blue production from sodium molybdate. The calculated parameter constants will be used to create secondary models, such as the influence of substrate and environment on Mo-blue synthesis.

Establishment and Application of a Predictive Growth Kinetic Model of Salmonella with the Appearance of Two Other Dominant Background Bacteria in Fresh Pork.

To better guide microbial risk management and control, growth kinetic models of Salmonella with the coexistence of two other dominant background bacteria in pork were constructed. Sterilized pork cutlets were inoculated with a cocktail of Salmonella Derby (S. Derby), Pseudomonas aeruginosa (P. aeruginosa), and Escherichia coli (E. coli), and incubated at various temperatures (4-37 °C). The predictive growth models were developed based on the observed growth data. By comparing R2 of primary models, Baranyi models were preferred to fit the growth curves of S. Derby and P. aeruginosa, while the Huang model was preferred for E. coli (all R2 ≥ 0.997). The secondary Ratkowsky square root model can well describe the relationship between temperature and μmax (all R2 ≥ 0.97) or Lag (all R2 ≥ 0.98). Growth models were validated by the actual test values, with Bf and Af close to 1, and MSE around 0.001. The time for S. Derby to reach a pathogenic dose (105 CFU/g) at each temperature in pork was predicted accordingly and found to be earlier than the time when the pork began to be judged nearly fresh according to the sensory indicators. Therefore, the predictive microbiology model can be applied to more accurately predict the shelf life of pork to secure its quality and safety.

Luminescence and optical properties of sodium germanate glasses doped with Sm3+ ions

Sm3+ doped sodium germanate glasses were synthesized by high temperature melt-quenching technique, suitable glass composition with optimum Sm3+ concentration and good luminescence thermal stability was obtained. The luminescence performance of Sm3+ and its optical transition property in glasses were studied. The optical transition intensity parameters of Sm3+ were calculated according to Judd-Ofelt theory. According to Huang's model and Dexter's model, it was confirmed that the electric dipole-dipole interaction among Sm3+ was responsible for the concentration dependent luminescence quenching of 4G5/2 level of Sm3+. Temperature dependent luminescence characteristics of Sm3+ was also investigated, and the luminescence thermal quenching behavior was found. When the temperature was 423 K, the emission intensity of the sample can still maintain 90% of that at room temperature. The result showed that this kind of red-emitting glass phosphor had an excellent luminescence thermal stability.

Effects of cinnamaldehyde on the germination and growth of Bacillus cereus spores in ready-to-eat boiled ground beef

The study quantitatively described the effects of cinnamaldehyde on the germination and growth of Bacillus cereus spores in boiled ready-to-eat ground beef. With the combination of the concentrations of cinnamaldehyde 0, 0.1, 0.5, and 1.0% vol/wt at temperatures 12, 20, 28, and 36°C, the Huang model was successfully used as the primary model to predict the lag time (λ) and maximum growth rate (µmax). Thereafter, the cubic polynomial models were used to estimate the values of Ln λ and Ln µmax considering both the storage temperature and cinnamaldehyde concentration. The models were highly accurate, because they produced acceptable root mean squared error (RMSE) values that were close to 0, while the determination (R2), accuracy factor (Af), and bias factor (Bf) values were all close to 1. As indicated by the fitted models, the supplementary of cinnamaldehyde in samples increased the lag time of B. cereus significantly from 17.7 to 75.8 h at 12°C of storage. Increasing the storage temperature from 12 to 36°C led to only 0.80-fold prolongation of lag time from 1.6 to 2.9 h in the sample containing cinnamaldehyde. However, the µmax value declined most obviously at 20°C, while 66% decrease was determined. According to the results, the cinnamaldehyde can be used as a natural antimicrobial agent in boiled ready-to-eat ground beef in staple food industry by inhibiting the germination and growth of B. cereus. The results also provided regressing models that can be used for effectively designing the storage temperature and cinnamaldehyde concentration for a specific requirement.

Efficiency assessment of a single surface dielectric barrier discharge plasma actuator with an optimized Suzen–Huang model

Spatial and time-resolved characteristics of a single surface dielectric barrier discharge (sDBD) actuator are experimentally and numerically investigated. The paper also focuses on the efficiency of sDBD actuators used as flow-control devices. The motivation is the need for developing a cost-effective way to optimize the balance between control performance and actuator power consumption. The study considers the steady state as often employed in experiments as well as the transient regime. Experimental methods to obtain the active power are revisited, and for the first time, the commonly used simplified phenomenological Suzen–Huang model (SHM) is used for the computation of electrical characteristics. The SHM represents fair qualitative features of the starting vortex. However, it fails when time-resolved velocity profiles are compared. Results show that even with an optimized parametrical analysis of the “tuned” plasma variables, the model is not able to fully reproduce the induced wall-jet neither spatially nor temporally. Furthermore, it underestimates the power consumption by more than 80%. The intrinsic challenge of accurately measuring the alternating current of the DBD and the instantaneous mechanical power, together with the failure of representing time-resolved velocity profiles and the underestimated electric power by the model, highlights that a better phenomenological model including gas dynamics and electric characteristics or using a fully coupled physical plasma model is required.

Growth simulation of Pseudomonas fluorescens in pork using hyperspectral imaging

Hyperspectral imaging (HSI) is a promising technique that can replace the time-consuming and destructive plate count method. In this study, growth models of Pseudomonas fluorescens (P. fluorescens) in pork using the plate count method and HSI were established. Hyperspectral information extracted by three different methods was used for the growth simulation of P. fluorescens. The Baranyi model in combination with the Ratkowsky square-root model (BRSR model) and the Huang model in combination with the Ratkowsky square-root model (HRSR model) for P. fluorescens in pork were directly constructed using a one-step method. Results showed that the correlation coefficients between the growth models established using HSI and the plate count method were high, ranging from 0.952–0.999. The adjusted coefficient of determination (Ra2) of simulation models reached 0.974, and the growth parameters obtained were consistent with those obtained using the plate count method. This study demonstrated that HSI may be potentially used as a new predictive microbial modeling technique in the future.

Fatigue Crack Growth Evaluation of IMO Type B Spherical LNG Cargo Tank Considering the Effect of Stress Ratio and Load History

The crack propagation on a spherical IMO Type B LNG tank deployed on a 150K class LNG carrier is studied. IMO Type B tanks require a high level of safety . Therefore, analyses such as strength evaluation, fatigue analysis, fatigue crack propagation analysis, and LNG leak rate should be conducted to ensure safety. Various fatigue crack growth models were proposed for fatigue crack propagation analysis. The Forman model and the Walker model consider the stress ratio. Furthermore, the Huang model, and the Lee and Kim model consider the stress ratio and the effects of overload and underload present in the past load history on crack propagation.To examine the effects of stress ratio and load history for the fatigue crack propagation models, the crack growth of the LNG tank was evaluated by considering the stresses under full load and ballast load operating conditions, and three stress amplitude sequence cases.

Predictive modeling and sensitivity analysis to estimate the experimental data of inulinase fermentation by Aspergillus niger grown on sugar beet molasses-based medium optimized using Plackett-Burman Design.

The present work aimed to model Aspergillus niger inulinase fermentation performed in the medium using sigmoidal functions, validate the selected models using an independent set of the experimental values, and perform a sensitivity analysis of the selected models. Based on the results, the selected models were Stannard and Fitzhugh models for substrate consumption (R2 = 0.9976 and 0.9974, respectively), Huang model for inulinase production (R2 =0.9967), Weibull model for invertase-type production (R2 =0.9963), and modified logistic model for invertase-type activity/inulinase activity ratio (R2 =0.9292) with high R2 values (>0.90). Kinetics predicted by particularly selected models mentioned above fit well with the experimental kinetic results. Besides, validation of the selected models with an independent set of the experimental data indicated that they gave satisfying results with high R2 values for consumption and production (R2 >0.90). Sensitivity analysis of the selected models showed that the yielded R2 values (R2 ≥0.9775) were in good agreement with those obtained from the selected models. Consequently, A. niger inulinase fermentation was successfully modeled and the selected models were successfully validated with an independent set of the observed data. Besides, the sensitivity analysis also verified the reliability of the selected models. Those models can serve as universal equations to describe the A. niger inulinase fermentation.