Hyperelastic models for the description and simulation of rubber subjected to large tensile loading

Purpose: Rubber is widely used in tires, mechanical parts, and user goods where elasticity is necessary. Some essential features persist unsolved, primarily if they function in excessive mechanical properties. It is required to study elastomeric Rubber's performance, which is operational in high-level dynamic pressure and high tensile strength. These elastomeric aims to increase stress breaking and preserve highly pressurised tensile strength. Design/methodology/approach: The effects of carbon black polymer matrix on the tensile feature of different Rubber have been numerically investigated in this research. Rubber's material characteristics properties were measured using three different percentages (80%, 90%and 100%) of carbon black filler parts per Hundreds Rubber (pphr). Findings: This study found that the tensile strength and elongation are strengthened as the carbon black filler proportion increases by 30%. Practical implications: This research study experimental tests for Rubber within four hyperelastic models: Ogden's Model, Mooney-Rivlin Model, Neo Hooke Model, Arruda- Boyce Model obtain the parameters for the simulation of the material response using the finite element method (FEM) for comparison purposes. These four models have been extensively used in research within Rubber. The hyperelastic models have been utilised to predict the tensile test curves—the accurate description and prediction of elastomer rubber models. For four models, elastomeric material tensile data were used in the FEA package of Abaqus. The relative percentage error was calculated when predicting fitness in selecting the appropriate model—the accurate description and prediction of elastomer rubber models. For four models, elastomeric material tensile data were used in the FEA package of Abaqus. The relative percentage error was calculated when predicting fitness in selecting the appropriate model. Numerical Ogden model results have shown that the relative fitness error was the case with large strains are from 1% to 2.04%. Originality/value: In contrast, other models estimate parameters with fitting errors from 2.3% to 49.45%. The four hyperelastic models were tensile test simulations conducted to verify the efficacy of the tensile test. The results show that experimental data for the uniaxial test hyperelastic behaviour can be regenerated effectively as experiments. Ultimately, it was found that Ogden's Model demonstrates better alignment with the test data than other models.

Application of Grey System Model to Forecast the Natural Gas Imports in China

China’s natural gas imports will keep an upward trend in the future due to its increasing demands. A comparatively accurate prediction of natural gas imports will help the Chinese government make appropriate decisions when formulating energy policies. In this paper, a new grey predication model, GPM_NGI model, was proposed to forecast China’s natural gas imports. Compared with GM (1, 1) and DGM (1, 1) model, the proposed new model performed better in the simulation process and bore smaller mean relative percentage error when used in simulating China’s natural gas imports from 2011 to 2019. Then, the new model was employed to forecast China’s natural gas imports from 2020 to 2022. The results showed that China’s natural gas imports would continue to grow rapidly over the next three years. Therefore, in order to strike a balance between the natural gas supply and demand in the future and avoid overdependence on imports, the Chinese government should take effective measures from both the supply and demand ends, such as making better use of shale gas, wind, and solar energy as well as reducing the industrial dependence on natural gas.

Evaluation of Ultrasonic Velocity Theories on Binary Liquid Mixtures of Propiophenone with Isomeric Xylenes at Temperatures (T = 303.15 to 318.15 K)

Densities (ρ), ultrasonic speeds of sound (u) of binary mixtures containing propiophenone with o-xylene, m-xylene and p-xylene were measured over the entire composition range at temperatures from 303.15-318.15 K and at atmospheric pressure 0.1 MPa. Experimental data of ultrasonic velocity was used to compute the theoretical velocities by using the various theories like Nomoto’s relation (UNOM), impedance relation (UIMP), Van Dael and Vangeel’s relation (UVDV), Rao’s specific velocity relation (URAO), Jouyban-Acree’s (UJOE) and Junjie’s theory (UJUN). The results are in good agreement with the experimental data. The relative percentage error, chi square test for goodness of fit and the molecular interaction parameter (α) values for non-ideality in the binary mixtures were computed and analyzed in terms of intermolecular interactions between the molecules of the binary mixtures.

Assessment of drip lateral design methods based on uniformity coefficient

In this paper, six drip lateral design methods were selected and a comparative assessment was done to find its practical applicability for finding accurate uniformity coefficient. Step-By-Step (SBS) method, Differential method (DM), Constant Discharge method (CDM), Variable discharge method (VDM), Outlet variation method (OVM) and Statistical method (STM) were the different methods assessed. The percentage relative error in calculating the uniformity coefficient by different methods were obtained as the difference between step-by-step method (true) value and alternate method (observed) value. These errors were tabulated. VDM and OVM method performed well with equal accuracy to SBS method at different slopes. For L=250m, DM method performed well. The STM performed good for down slope and lateral length of 250m with 6 per cent relative error. The method having lesser relative percentage error can be selected by the design engineers for designing the laterals from the relative percentage error tables.

An aptamer-based electrochemical biosensor for simple and sensitive detection of staphylococcal enterotoxin B in milk

The relative percentage error between the proposed method and ELISA ranged from −8.38 to 8.33, which indicates that there is no significant difference between the results.

A Stability-Indicating HPLC Method for the Quantification of Aliskiren and Hydrochlorothiazide in a Pharmaceutical Formulation

A novel, fast, and sensitive stability-indicating HPLC method was developed, fully validated, and applied to the simultaneous determination of aliskiren and hydrochlorothiazide in a combined formulation. Effective chromatographic separation was achieved using a phenyl analytical column with isocratic elution using the mobile phase 0.030 M ammonium acetate–acetonitrile (60 + 40, v/v) at a flow rate of 0.40 mL/min. The UV spectrophotometric detector was set at 280 nm. The method was linear over the concentration ranges of 1.5–4.5 and 0.125–0.375 μg/mL for aliskiren and hydrochlorothiazide, respectively. The intraday and interday RSD values were less than 6.1%, while the relative percentage error, Er, was less than 5% for both analytes. Both drugs were subjected to stress conditions of acidic and alkaline hydrolysis, oxidation, and thermal degradation. The proposed method proved to be stability indicating by resolution of the drugs from their forced degradation products. The method was applied successfully to the QC and content uniformity tests in combined commercial tablets.

Sorption isotherms for oat flakes (Avena sativa L.)

Moisture sorption isotherms of oat flakes were determined at temperatures of 5, 25 and 37°C, using a gravimetric technique in an aw range of between 0.107 and 0.855. These curves were modeled using six equations commonly applied in food. The quality of the fit was assessed with the regression coefficient (r2) and the mean relative percentage error (MRPE). The best fit were obtained with the Caurie model with r2 of 0.996, 0.901 and 0.870, and MRPE of 7.190, 17.878 and 16.206, at 5, 25 and 37°C, respectively. The equilibrium moisture presented a dependence on temperature in the studied aw range, as did the security moisture (XS). These results suggest that the recommended storage conditions of oat flakes include: a relative air humidity of 50% between 5 and 25°C and of 38% up to 37°C.

Dry Characteristics and Kinetics of Explosion Puffing Dried Crispy Winter Jujube at Different Vacuum Drying Temperature

Drying characteristics of crispy winter jujube dried by explosion puffing drying at different vacuum drying temperature were investigated. Selection of the best model was examined by comparing the determination of coefficient (R2), root means square error (RMSE), and mean relative percentage error (P) between the experimental and predicted values. As expected, higher drying rates were obtained with higher vacuum drying temperature. The results showed that the Modified Henderson and Pabis model provided better simulation of drying curves for crispy winter jujube according to thin-layer drying theory. The effective moisture diffusivity of crispy winter jujube dried by explosion puffing drying with higher vacuum drying temperature was higher than the others.

Desorption Isotherm of Mango Soy Fortified Yoghurt

Desorption isotherms of three yoghurt samples viz. plain yoghurt, mango soy fortified yoghurt (MSFY) and MSFY containing 0.4 % gelatin stabilizer (MSFYG) were determined by gravimetric static method at 20, 30, 40 and 50 °C in the range of 0.11 – 0.81 water activity. It was found that desorption isotherm of yoghurt samples follow a typical type III sigmoid curve. Experimental data were fitted to five mathematical models i. e. modified Henderson, modified Chung Pfost, Oswin, Smith and Guggenheim-Anderson-deBoer (GAB). Equations were developed for the prediction of the GAB constants as a function of temperature and these equations were used during modeling. Standard error of estimate (SE), mean relative percentage error (P), percent root mean square (% RMS) and trend of residual plots were used to compare the goodness of fit. It was found that the GAB models were acceptable in describing equilibrium moisture content – water activity relationships for yoghurt samples over the entire experimental temperature range.