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The supercritical organic Rankine cycle is a critical technology for efficiently using medium- or low-temperature heat sources, where heat transfer by supercritical organic fluids is crucial. This study experimentally investigates the heat-transfer performance of supercritical-pressure R134a in a heated tube and predicts its heat transfer coefficient. The wall-temperature distributions and heat transfer coefficients are obtained. Moreover, the buoyancy effect on the heat transfer is discussed. The results show that the buoyancy effect is evident in low-enthalpy regimes, and it is more significant at lower mass and higher heat fluxes but is slightly affected by pressure. Furthermore, empirical correlations and an artificial neural network (ANN) model are adopted to predict the heat transfer coefficient, and their prediction performances are quantitatively evaluated. The results show that the ANN prediction performance is significantly improved over traditional correlations, demonstrating that ANN is an effective tool for predicting the heat-transfer performance of supercritical-pressure fluids. [Display omitted] • Heat transfer coefficient of supercritical-pressure R134a were measured. • Buoyancy effect has an important impact on heat transfer of supercritical fluids. • ANN model could predict heat transfer of supercritical fluid with high accuracy. [ABSTRACT FROM AUTHOR]

In this experiment, the changes in protein hydrolysis, protein oxidation, and flavor of low-salt wet-marinated fermented golden pomfret were studied during processing. During processing, a decrease in sulfhydryl content (P < 0.05), a significant increase in protein surface hydrophobicity (P < 0.05), a significant increase in carbonyl content and TCA-soluble peptide (P < 0.05), an increase in TVB-N and amino acid nitrogen (P < 0.05), and a significant increase in the content of free amino acids (P < 0.05), indicating that proteins were gradually oxidized and degraded to small molecules and flavor precursors under the action of bacterial reduction pretreatment, deodorization, marination and fermentation processes, small molecules and aroma precursors was generated by gradual oxidative decomposition. In the course of processing, a total of 113 volatile flavor compounds were identified using GC–MS analysis, while OPLS-DA analysis and VIP value determination led to the identification of 10 characteristic flavor compounds. The results showed that an abundance of flavor compounds was generated during the processing, thereby imparting a more pronounced taste profile to the low-salt wet-marinated fermented golden carp. The results showed that a large number of flavor substances were generated during the processing to give a richer flavor to low-salt wet-marinated fermented golden pomfret that could provide data and theoretical support for the subsequent processing industry of golden pomfret. • Marination and fermentation promote oxidative breakdown of proteins • Fermentation golden pomfret is very rich in free amino acids. • The different components that have been identified make up the unique flavor of fermented golden pomfret. • A significant increase in the content of flavor compounds in the processed golden pomfret fish [ABSTRACT FROM AUTHOR]

• Convection heat transfer of supercritical hydrocarbon fuel is experimentally investigated in a long mini tube. • Heat transfer of supercritical hydrocarbon fuel is divided into four regions. • Heat transfer mechanisms of supercritical hydrocarbon fuel are discussed under various heat fluxes. Thermal management system is crucial for hypersonic vehicles, in which a large amount of thermal energy due to aerodynamic heating needs to be removed by hydrocarbon fuel. In this study, an experimental investigation is performed on the convection heat transfer of supercritical hydrocarbon fuel in a long mini tube. The horizontal test tube has an inner diameter of 1.0 mm and a length-to-diameter ratio of 980, which are close to those of practical heat-transfer channels in the thermal management system for hypersonic vehicles. The non-linear distribution characteristics of wall temperature and heat transfer coefficient along the test tube are presented. The heat transfer regions of hydrocarbon fuel are classified into initial heat transfer (IHT), normal heat transfer (NHT), enhanced heat transfer (EHT) and deteriorated heat transfer (DHT). The heat transfer mechanisms in each heat transfer region are discussed in detail. The heat transfer of hydrocarbon fuel are affected by the dramatic variations in thermo-physical properties and buoyancy effect. Heat transfer is commonly deteriorated under disadvantageous thermo-physical properties and absence of buoyancy effect. The results could be beneficial for the analysis and design of the thermal management system for hypersonic vehicles. [ABSTRACT FROM AUTHOR]

• Heat transfer of supercritical CO 2 (S-CO 2) was experimentally studied under high ratio of heat flux to mass flux (q / G) conditions. • Heat transfer deterioration of S-CO 2 and the buoyancy effect under high q / G conditions were analyzed. • A number of heat transfer correlations for S-CO 2 were compared with the experimental data. • A new correlation was proposed to predict the heat transfer of S-CO 2 under high q / G conditions. Supercritical carbon dioxide (S-CO 2) power cycles hold great potential applications in various energy utilization systems, in which the heat transfer of S-CO 2 is one of the most important issues. However, due to the complex thermophysical properties, it is still insufficient to predict heat transfer coefficient of S-CO 2 , especially under the heating conditions with high ratios of heat flux to mass flux (q / G). In this study, the heat transfer of S-CO 2 is experimentally investigated in a mini tube (d = 2 mm) in the range of p = 7.6–8.4 MPa, q = 100–200 kW/m2 and G = 400–700 kg/m2 s, in which the ratio of q / G is within 250–500 J/kg. The parameter influences on heat transfer coefficient of S-CO 2 are analyzed. It is found that the heat transfer coefficient decreases with increasing heat flux and decreasing mass flux, but is little affected by pressure. Under high q / G conditions, buoyancy effect is significant and heat transfer is deteriorated in the whole test section. Available heat transfer correlations for S-CO 2 are compared with the experimental data; however, the prediction errors of these correlations are relatively high, especially in pseudo-critical regions. As a result, a new heat transfer correlation is developed for S-CO 2 under high q / G conditions, in which buoyancy effect and variations in thermophysical properties are both taken into account. [ABSTRACT FROM AUTHOR]

Recent developments in the legal establishment and the market have motivated more agro-food companies to implement traceability systems (TS). TS play an important role not only for planning system implementation before development, but also for analyzing system performance after using the system. A novel agro-food TS model is presented here, based on comprehensive and quantifiable granularity concepts. A 2-layer index system was established; the first layer was mainly factors such as precision, breadth, and depth, and the second layer included seven indicator sub-factors: external trace units, internal flow units, IU conversion, information collection content, information update frequency, forward tracking distance, and backward tracing distance. An indicator’s overall score was scaled with five contributing scores that graded the assignment method. Indicator weight was confirmed with the AHP method. The weight values of the seven indicators were 0.1985, 0.1141, 0.0872, 0.1870, 0.1248, 0.1442, and 0.1442, respectively. A weighted sum model was adopted to calculate the evaluation value. A high evaluation value indicated high granularity. The granularity model was applied in two enterprises, here identified as WPF and WFPE, which were located at different stages in wheat-flour supply chain. The survey results showed that WFPE should invest more in tracing equivalent granularity than WPF should because it involves multi-stage processing, a complicated supply chain structure, it is a large enterprise, and operates in a strict regulatory environment. Furthermore, WFPE was motivated to implement a high granularity level because of benefits in supply chain management, market and customer response, and recall and risk management. In the future, an updated granularity evaluation model that could combine enterprise characteristics and uncover hidden costs and benefits will be studied further. [ABSTRACT FROM AUTHOR]

[Display omitted] • A low-molecular weight sulfate glycosaminoglycan (D-SBSG) was obtained from the freshwater fish swimming bladder of Aristichthys nobilis by hyaluronidase enzymatic degradation. • The bioactivities had arose dramatic differences, whereas main molecule structure of D-SBSG had little change after enzymatic degradation. • The low-molecular weight sulfate glycosaminoglycan (D-SBSG) possessed higher anti-inflammatory effect. • D-SBSG can be considered to develop nutraceutical or cosmetic with anti-inflammatory effects. Low molecular weight sulfate glycosaminoglycan has attracted more attention recently for its great bioactivity. In the present study, a degraded sulfate glycosaminoglycan (named D-SBSG) was prepared from swimming bladder by enzymatic depolymerization, the structure characteristics of D-SBSG and its effects on blood coagulation and inflammation in vitro was investigated. HPGPC analysis showed that the molecular weight (Mw) of SBSG was 115.84 kDa, while the Mw of D-SBSG was 4.96 kDa. The bioactivities had arose dramatic differences, though its main molecule structure had little change after enzymatic degradation. Compared with heparin sodium, relatively milder anticoagulant activity in vitro , which were positively associated with molecular weight, were found in SBSG and D-SBSG. In contrast, the results of anti-inflammatory assays indicated that D-SBSG with the lower molecular weight possessed higher bioactivity than SBSG. Additionally, the D-SBSG inhibited the LPS-induced inflammatory in RAW264.7 macrophages by down-regulation of inflammatory mediators, both of NF-κB (including p65) and MAPK (including p38) signaling pathways to exert its anti-inflammatory function. These results indicated that enzymolysis is a viable strategy for degradation of sulfate glycosaminoglycan, and D-SBSG could be a promising ingredient for inflammation management. [ABSTRACT FROM AUTHOR]