54 results about "Arrhenius equation" patented technology

The invention discloses a calculation method for the remaining shelf life of fruits and vegetables and provides a calculation method for determining the remaining shelf life of fruits and vegetables by the hardness index. The calculation method comprises the following steps: firstly measuring an initial hardness value Q of the fruits and the vegetables, and simultaneously measuring a transformation relation of the hardness of the fruits and the vegetables with time under different temperatures; establishing a dynamic model of the fruits and the vegetables by adopting a first-order chemical reaction dynamic equation InAt=lnA0-kt, carrying out linear regression fitting on a hardness and time relation of the step, and thus obtaining a hardness-change rate constant ki of the fruits and the vegetables under different temperatures; applying an Arrhenius equation shown in the specification and combining the hardness-change rate constant ki of the fruits and the vegetables under different temperatures and a fitting-equation determination coefficient to obtain a relation curve graph shown in the specification of the fruits and the vegetables, obtaining a curve fitting equation from the obtained relation curve graph and determining the inclination and the intercept of the fitting line, wherein the mass equation of the fresh-eating fruits and vegetables is shown as the specification, the equivalent transformation is shown in the specification, and then the shelf life t of the fruits and the vegetables under the ambient temperature can be calculated.

The invention relates to a new method for researching the asphalt thermal decomposition behavior by deepening into the asphalt component level, belongs to the field of fire disaster safety and solves the problem that the current asphalt thermal decomposition behavior research is difficultly thorough. The method comprises the steps of: firstly, preparing component test samples, determining component content, testing the thermal decomposition property of asphalt and four components thereof by adopting differential scanning calorimetry-infrared spectroscopy technology, acquiring the thermal decomposition test data of all components in the asphalt, analyzing the thermal decomposition gradient distribution character of all the component and producing smoke ingredient and release rule; secondly, calculating the thermal analysis kinetic parameters of all the components according to the Arrhenius equation, and establishing a thermal decomposition kinetic model; finally, testing the microstructure, components and content of residues of the thermally-decomposed components by adopting a transmission electron microscope and aphotoelectron spectroscopy instrument, researching the thermal decomposition behavior of all the components in asphalt, and comparing with the asphalt test sample test results, and revealing the asphalt thermal decomposition mechanism. The method can fundamentally reveal the thermal decomposition behavior of asphalt under the high-temperature environment.

An electronic device is proposed for accompanying a perishable good during one period to monitor the exposure of the good to an environmental parameter, such as temperature. The device includes a data interface for receiving data representing the exposure of the good to the environmental parameter during an immediately preceding period. It further includes a sensor for measuring the environmental parameter. Also, the device includes a processor for using a relationship specific to the good (such an Arrhenius equation for that good) to compute a characteristic of the good at the end of the one period using the received data and the output of the sensor. The device further includes a memory for recording the output of the sensor. To economise on memory usage, data is stored at a faster rate during periods when the data is of most significant (e.g. it indicates a high temperature). A switch is provided for indicating that data should not be taken into account in the computation, during a short interval, in which for example the device may be being handled.

The invention discloses an asphalt aging performance prediction method based on isothermal thermal analysis kinetics, belongs to the technical field of road asphalt pavement durability, and solves problems that an asphalt aging process cannot be predicted accurately and more practical asphalt aging performance prediction cannot be provided for pavement management and maintenance work when attenuation of a macroscopic performance index of the asphalt is adopted to speculate a pavement performance degradation degree at present. The asphalt aging performance prediction method provided by the invention comprises the following steps: firstly, selecting an asphalt sample, testing with a thermal analyzer, simulating thermal-oxidative aging of the asphalt to obtain TG and DTG data and a char yieldof the asphalt; secondly, selecting a reaction mechanism function corresponding to the asphalt aging process according to a chemical structure, a functional group and thermal stability change of theasphalt aging process to establish an isothermal thermal analysis kinetics model of the asphalt; finally, using an aging-time equivalence principle to analyze equivalence of the asphalt aging processand time, calculating an isothermal aging shift factor by an Arrhenius equation to predict the asphalt aging performance, thereby providing a basis for decision-making of an asphalt pavement maintenance scheme.

The invention relates to a method for calculating the thickness of an oxide film of martensitic heat-resistant steel under supercritical high-temperature steam. The method is particularly suitable for9% Cr martensitic heat-resistant steel. According to the method, a parabola model of metal oxidation kinetics is utilized; mathematical correction is carried out on the Arrhenius equation on the basis of the parabola model; a large number of actual operation results of a power plant and simulation experiment data are comprehensively taken into consideration; an oxide film thickness calculation formula of the 9% Cr martensitic heat-resistant steel in a high-temperature steam environment with a temperature of 23-35MPa is obtained by using a step-by-step linear fitting method and a function curve fitting method; and according to the formula, the influence of time and temperature on the thickness of the oxide film is comprehensively taken into consideration, and the thickness of the oxide film of the 9% Cr martensite heat-resistant steel under the condition can be calculated by substituting steam temperature and running time into the formula. The formula breaks through the limitation thatmost oxidation kinetic models only consider the influence of a single factor, and overcomes the defects that traditional oxide skin thickness measurement method is long in test period, high in cost,complex in operation and unstable in precision, or need to cut a steel pipe and the like.

A technique for determining the relative humidity of the cathode input airflow to a fuel cell stack that eliminates the need for a dew-point sensor. The cathode input airflow is humidified by a water vapor transfer unit that uses water in the cathode exhaust gas. The technique employs an algorithm that determines the flow of water into the cathode inlet of the stack. In one embodiment, the algorithm determines the volume flow of water through the water vapor transfer unit using the Arrhenius equation, and then converts the water volume flow to a water mole flow. The algorithm then uses the water mole flow through the water vapor transfer unit and the water mole flow of ambient air to determine the water mole flow into the cathode inlet. The algorithm then uses the water mole flow into the cathode inlet to determine the relative humidity of the cathode airflow.

The invention relates to the technical field of electrical equipment fault diagnosis, and discloses a bushing insulation oil paper temperature correction and activation energy prediction method based on dielectric modulus, comprising the following steps: obtaining an expression of a dielectric model M (omega); preparing experimental samples with different moisture contents, and performing frequency domain dielectric spectrum testing on the samples at different temperatures to obtain an FDS curve corresponding to a complex dielectric constant; converting the FDS curve corresponding to the complex dielectric constant imaginary part to obtain an FDS curve corresponding to M ''(omega); positioning the peak frequency fp of the FDS curve corresponding to the M "(omega) by using a least square method, and obtaining the change rule of the fp along with the temperature and the moisture; defining a translation factor, and obtaining a rule that the translation factor changes along with temperature and moisture; introducing a classical Arrhenius equation into activation energy calculation, and obtaining an activation energy calculation formula related to the translation factor; and establishing an activation energy prediction model. According to the invention, the influence of temperature and moisture in the oil-paper insulation system on activation energy is considered, and the method is of great significance to aging evaluation of on-site bushings.

The invention discloses an oil paper insulation aging state evaluation method and system based on activation energy iterative correction. By utilizing an iterative algorithm, activation energy is continuously corrected in an oil paper insulation aging state evaluation iteration process, so that the activation energy error is reduced and the accuracy of a temperature normalization process is improved. The method comprises the steps of carrying out temperature normalization processing on a frequency domain dielectric spectral curve of tested oil paper insulation equipment by utilizing an Arrhenius equation; carrying out curve fitting on the frequency domain dielectric spectral curve subjected to the temperature normalization processing and an H-N model to obtain characteristic parameters tau, alpha and beta of the H-N model; and matching the characteristic parameters with a database of oil paper insulation H-N models with different aging states to determine an oil paper insulation agingstate. An evaluation result has relatively high accuracy and reliability.

The invention discloses a method for improving shelf life of a saltwater-freshwater bdellovibrio sp. microbial preparation. The method comprises the following steps: preparing the bdellovibrio sp. microbial preparation; mixing the bdellovibrio sp. microbial preparation with a protection agent belonging to different kinds and / or with different concentration, so as to obtain a mixed solution; placing the mixed solution at different temperature to perform accelerated testing; sampling regularly, and detecting the live bacteria concentration of the bdellovibrio sp. microbial preparation in the mixed solution; and utilizing Arrhenius equation and recorded data to calculate out the shelf life of the bdellovibrio sp. microbial preparation, and determining the effect of the protection agent by comparing the shelf life. According to the method, by comparing the quality-guaranteeing effect of different protection agents on the bdellovibrio sp. microbial preparation, a protection agent with best quality-guaranteeing effect is screened out, and the shelf life of the bdellovibrio sp. microbial preparation is obviously prolonged; and also the activity of thalline in the bdellovibrio sp. microbial preparation can be effectively kept for a long time. The provided protection agent is wide in raw material selection scope and cheap in price, and is suitable for popularization and usage.

The invention provides a leaf spring normal-temperature and high-temperature stress relaxation life predicting method. Firstly, a spring sample to be tested is prepared, and the prepared spring sample to be tested is an equal stress sample; then a test device is arranged, side plates are fixed at the front part and the rear part of a base of the test device, two ends of the sample are respectively arranged on the side plates, the base and an upper plate are fixed together through limiters, a pressure sensor is arranged on the upper plate, and a pressure head arranged at the lower end of the pressure sensor applies pressure on the sample; and then a spring stress relaxation experiment is carried out, stress values at different time are acquired to determine the stress relaxation loss condition of a sample material after the regulated experiment time is up, test data is selected according to failure criteria, the data is processed by an empirical formula and an Arrhenius equation, and finally the life of the sample at the normal temperature is determined. According to the method disclosed by the invention, sample bending deflection which is not easy to measure is converted into an electrical signal which is easy to measure, the work efficiency is improved, the method is simple, and the obtained life prediction result is accurate.