Search

Background Cooked meat is a good source of high-quality protein. However, during long-term cooking of meat, radical-induced lipid and protein oxidation may lead to the formation of poisonous compounds, such as heterocyclic amines (HAs). This work investigated a testing method for HAs and it describes that cooking temperature, cooking time and repeated cooking times have influences on the overall quality of braised sauce beef and the effect of HAs formation. Results The improved method has a good separation effect on nine kinds of HAs. The average recovery of HAs at two spiked levels is between 51.70% and 88.25% (n = 6). The detection limit is 0.025-0.060 ng g-1 , and the limit of quantitation is 0.070-0.160 ng g-1 . Only harman and norharman were detected in samples. Cooking time and cooking temperature will affect the quality and HA content of samples. When the braised sauce beef soup was cooked 20 times, the HA content was the highest - as high as 21.43 ng g-1 . The more times the beef was cooked repeatedly, the higher was the HA content. Under different cooking conditions, glucose has a significant effect on the formation of β-carboline. Conclusion We have established a detection method for HAs with good repeatability and accuracy. HAs were more easily formed in braised sauce beef by high temperature, long heating and repeated brine cooking. © 2021 Society of Chemical Industry.

This paper took plate workshop of A furniture production enterprise as research object, and analyzed logistics situation of workshop according to data materials such as material flow of workshop and distance between production processes of workshop, and found out problems existing in layout of workshop facilities of the company. Then, targeting at these problems, system layout planning method was used to analyze logistics relationship, non-logistic relationship, and comprehensive relationship, diagram of work area was drew and an improvement plan for the company’s workshop layout was proposed. Finally, simulations of the front and post improvement scenarios were simulated by flexsim simulation software and effects were evaluated.

With the span of CFST (Concrete Filled Steel Tube) arch bridges getting much longer, the dynamic performance of them is becoming more and more advanced. In order to evaluate the structure of CFST arch bridges in a comprehensive way, it is necessary to take the dynamic performance of this kind of bridges into consideration. Methods of doing the dynamic analysis can be divided into two kinds: one is traditional theoretical analytical method, which is only suitable for simple arch bridge models; the other is FEM (Finite Element Methods), which is able to simulate the real structure and lead to more precise results. This paper attempts to study the calculation theory of free vibration characteristic of arch bridges through theoretical analytical method, and then it will do an empirical study on the dynamic performance of a CFST arch bridge by FEM to test the conclusion of theoretical study.

For over 40 years, the universal soil loss equation (USLE) and its revised version the revised universal soil loss equation (RUSLE) have been used all over the world for soil mean annual loss per area unit. Because of the watershed erosion models are under developing, many researchers applied the USLE and RUSLE to estimate soil loss in watershed estimations. However, a major limitation is the difficulty in extracting the LS factor. The geographic information system-based (GIS-based) methods which have been developed for estimating the slope length for USLE and RUSLE model also have limitations. A series of ARC/INFO AML program was created that can calculate LS factor for the USLE, however the program need a very long time to run in wide-ranging areas. The flowpath and cumulative cell length-based method (FCL) overcomes this disadvantage but does not consider the following questions: (1) Some original AML program functions are not achieved, so results are different. (2) Using USLE to calculate LS factor that do not adapt to the erosion environment of China. (3) There isnt a friendly graphic user interface. The purpose of this research was to overcome these limitations and extend the FCL method through Integrating CSLE equation. We developed a LS calculation tool (LS-TOOL) in Microsofts .NET environment using C# with a user-friendly interface. Comparing the LS factor calculated with the FCL method and AML method, LS factor values generated by using LS-TOOL method delivers improved results. The LS-TOOL algorithm can automatically calculate slope length, slope steepness, L factor, S factor, and LS factors, providing the results as ASCII files which can be easily used in some GIS software. This study is an important step forward in conducting fast large-scale erosion evaluation.

A mesogenic crosslinking agent M-1 was synthesized to minimize the perturbations of non-mesogenic crosslinking agents in liquid crystalline elastomers. The synthesis of new side chain liquid crystalline elastomers containing the rigid mesogenic crosslinking agent M-1 and nematic monomer M-2 by a one-step hydrosilylation reaction is described. The chemical structures of the monomers and network polymers obtained were confirmed by FTIR and 1H NMR spectroscopy. The mesomorphic properties and phase behaviour were investigated by differential scanning calorimetry, polarizing optical microscopy, and X-ray diffraction. The influence of the crosslinking units on phase behaviour is discussed. Liquid crystalline elastomers containing less than 15 mol % of the crosslinking units showed elasticity, reversible phase transitions and a threaded texture. The experimental results demonstrated that the glass transition temperature of polymers P-1–7 increased with increasing concentration of crosslinking agent M-1; but the ...