Predicting the Mechanical Properties of RCA-Based Concrete Using Supervised Machine Learning Algorithms.

Environment-friendly concrete is gaining popularity these days because it consumes less energy and causes less damage to the environment. Rapid increases in the population and demand for construction throughout the world lead to a significant deterioration or reduction in natural resources. Meanwhile, construction waste continues to grow at a high rate as older buildings are destroyed and demolished. As a result, the use of recycled materials may contribute to improving the quality of life and preventing environmental damage. Additionally, the application of recycled coarse aggregate (RCA) in concrete is essential for minimizing environmental issues. The compressive strength (CS) and splitting tensile strength (STS) of concrete containing RCA are predicted in this article using decision tree (DT) and AdaBoost machine learning (ML) techniques. A total of 344 data points with nine input variables (water, cement, fine aggregate, natural coarse aggregate, RCA, superplasticizers, water absorption of RCA and maximum size of RCA, density of RCA) were used to run the models. The data was validated using k-fold cross-validation and the coefficient correlation coefficient (R2), mean square error (MSE), mean absolute error (MAE), and root mean square error values (RMSE). However, the model's performance was assessed using statistical checks. Additionally, sensitivity analysis was used to determine the impact of each variable on the forecasting of mechanical properties.

Physiochemical properties and tastes of gels from Japanese Spanish mackerel (Scomberomorus niphonius) surimi by different washing processes.

The study investigated the properties of gels from Japanese Spanish mackerel (Scomberomorus niphonius) (JSM) surimi received conventional washing (CW) or alkaline-saline washing (AW) and un-washing (UW). AW gel exhibited the highest breaking force and deformation as well as water-holding capacity, but CW gel only had higher breaking force than UW gel. Low-field NMR analysis showed that peak P22 in AW gel was shifted to higher relaxation time and the areas of peak P21 and P22 in AW gel were higher than those in UW and CW gels. Compared with UW gel, network structure of AW gel was more continuous with many tiny voids, but CW gel microstructure showed partially uneven area with large voids. SDS-PAGE showed that band intensity of myosin heavy chain attenuated more in AW gel than in UW and CW gels in nonreducing electrophoresis and it recovered more pronounced in reducing electrophoresis. Solubility attributed to hydrophobic interaction, hydrogen and disulfide bonds increased in CW and AW gels. AW gel gave stronger bitterness and aftertaste A while CW gel showed heavier sourness, astringency, and aftertaste B than UW gel. Results suggest that AW improved physiochemical properties of gel and preserved a closer taste pattern to UW gel. It is recommended for JSM surimi producing. PRACTICAL APPLICATIONS: Surimi food has great potential due to its convenience, elasticity, and nutritional value. Japanese Spanish mackerel (JSM), a popular fish species in China, is widely used for producing surimi food, such as fish ball, dumpling, and sausage. Washing is a practical way to improve its gel properties. This study investigated the gel strength, water status, protein pattern, molecular interactions, microstructure, color, and taste of gels from JSM surimi received conventional washing or alkaline-saline washing and un-washing. Some practical information of effects of washing on gel properties was obtained. These results provide supports to the gel properties improvement by appropriate washing for JSM.

Effects of deodorization by powdered activated carbon, ß-cyclodextrin and yeast on odor and functional properties of tiger puffer (Takifugu rubripes) skin gelatin.

The study investigated odor, physiochemical and functional properties of tiger puffer skin gelatin (TPSG) deodorized by powdered activated carbon (PAC, 0.5%), ß-cyclodextrin (ßCD, 3%) and yeast fermentation (YEF, 1%). Sensory test and electronic nose analysis exposed that three treatments lowered fishy odor intensity, coincided with decreased categories and levels of volatile compounds. Amide I, II and B of group ßCD were shifted to lower wavenumber and amplitudes of amide bands in group YEF were much lower than those of others. Gel strength of group ßCD and YEF declined, coincided with their higher relaxation time (component T22 and T2b) (p < 0.05). Marked decreases in gelling and melting temperature were found in group ßCD. Emulsion activity index of group YEF decreased (p < 0.05) while emulsion stability index of all deodorized groups increased (p < 0.05). Different from uneven clusters with large size emulsion droplets in control, a homogenous system with small size droplets was observed in group YEF. PAC filtration increased clarity and lowered b* value (p < 0.05), but ßCD treatment greatly decreased clarity (p < 0.05). Results suggest that YEF and ßCD treatment deteriorated physical and functional properties of TPSG. Nevertheless, PAC filtration reduced fishy odor without compromising physiochemical and functional properties and is recommended for TPSG deodorization.

Physiochemical and functional properties of tiger puffer (Takifugu rubripes) skin gelatin as affected by extraction conditions.

The study investigated physiochemical and functional properties of gelatins from tiger puffer skin (GTPS) extracted with warm-water method at 45, 55 and 65°C for 3, 6 and 12h. GTPS45 exhibited strong γ-, ß-, α1- and α2-chains, but they faded with the presence of fragments (<80KDa) in other GTPS. As the increase of temperature and time, amide I and A were shifted to higher wavenumber and their amplitudes in GTPS65-12 decreased. Lightness declined while redness and yellowness were enhanced. Gel strength was in a range of 144.5-79.8g, where it of GTPS45-3 was the highest while it of GTPS65-12 was the lowest (p<0.05), coincided with the longer relaxation time of T22 for immobilized water. Decline in gelling and melting temperature was observed when temperature and time increased. EAI and ESI increased as time prolonged or temperature climbed (p<0.05), in agreement with the form of emulsion droplet by microscopy. Both category and level of volatile compounds increased GTPS65-12 and 55-12 compared with those in GTPS45-12. Results suggest that temperature and time greatly affect the properties of GTPS. To ensure good properties, GTPS should be extracted at a temperature of 45-55°C for less than 12h.