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Stone waste refers to the waste stone particles generated from mining and stone processing to finished products that are not utilized in a resourceful manner. In this study, a CGF solid waste-based binder (abbreviated as CGF), with calcium carbide residue (CCR), ground granulated blast-furnace slag (GGBS), and fly ash (FA) as components, was developed to solidify the stone waste. Through “treating waste with waste”, the resource utilization of solid waste was realized. In order to improve the performance of the new material, this paper proposes the MAA-SW model for stone waste pavement base material based on the MAA model, establishes the relationship with the target gradation, and obtains the ideal gradation composition of stone waste through the calculation of the response surface analysis so as to obtain an energy-saving stone waste pavement base material with excellent performance.

This study investigated the synergistic effects of three protein concentrates from legumes (pea, lentil, and lima bean) as emulsifiers and stabilizers of oil-in-water (O/W) emulsions using a simplex-centroid mixture design. The aim was to check whether proteins combined in different proportions have better emulsifying properties than isolated proteins. During this study, each protein concentrate was characterized by different evaluated parameters: emulsifying activity, emulsion stability, accelerated stability test, thermal coagulation time, stability to coalescence, and others. After statistical analysis mixture optimization, it was found that the best formulation for stabilizing O/W emulsion under the tested conditions (2% total protein; 3% sunflower oil) was the protein blend containing 21.21% pea, 32.78% lentil, and 46.01% fava bean. This blend exhibited better emulsification properties compared to the individual proteins.

The substrate that adheres between the teeth of the traveling track plate during the operation of a deep-sea polymetallic nodule mining vehicle affects the driving performance, so this study aimed to investigate the effect of the water jet on the cleaning and decontamination performance of the track under different conditions. An optimization design method based on response surface methodology (RSM) is proposed. Based on the Box–Behnken design, the optimization variables of jet pressure, jet target distance, and impact angle, and the target response of jet strike pressure on tracks, were selected, and the numerical simulation method was combined with the response surface method to establish the regression model of the response of each optimization variable to the jet strike pressure on tracks and to determine the optimal parameter combinations. The study findings indicate that the primary factor influencing the pressure of the jet striking the crawler is the jet pressure. The hierarchical order of influence on the pressure of the jet striking the crawler, under the interaction of the three factors, is as follows: jet pressure and impact angle, jet pressure and target distance of the jet, and target distance of the jet and impact angle. The maximum pressure of the jet striking the crawler occurs when the jet pressure is 0.983 MPa, the target distance is 0.14 m, and the impact angle is 89.5°. Overall, the proposed design serves as a systematic framework for parameter optimization in the cleaning and decontamination process, and the research method and results provide theoretical references for the optimal design of mining truck desorption efficiency, which is critical for increasing mining efficiency and lowering energy consumption.

Additive manufacturing procedures are being increasingly developed, from prototyping to finished functional products. However, their rapid development also brings along the testing of properties with different manufacturing parameters. In selective laser sintering, the most influential manufacturing parameter is the energy density, which also consists, among other things, of the hatch distance. For better usage of the entire chamber and a reduction in the overall price of the finished product, in practice, the manufacturing of products at different heights (levels) of the working chamber with different orientations is inevitable. The study examines how hatch distance and product orientation impact the tensile strength and dimensional stability of polyamide products across two levels within the chamber. Upon analysis, it was observed that manufacturing products at different levels within the working chamber does not influence their dimensions. Achieving precise product dimensions comparable to those in the CAD model is possible. Furthermore, the same factors (orientation and hatch distance) and their combinations affect the length, thickness, and width of the product. Although all test specimens were tested, a tensile strength analysis of variance (ANOVA) of test specimens produced at the lower level of the chamber with a combination of hatch distance (ranging from 0.23 to 0.6 mm) and orientation (ranging from 0° to 60°) was not feasible in the design of the experiment. Despite this limitation, it was noted that both chamber levels had the potential to reach a maximum tensile strength of 47 N/mm2. Nevertheless, the average tensile strength of PA12, obtained through combinations of input factors, stood at only 30 N/mm2, which is quite a low value for polyamide made by selective laser sintering.

Ship resistance has a very important value in the determination of ship power and the design of emission standards. In this paper, a ship resistance model with different displacement, speed, and attachment under the condition of a fixed scale ratio is tested by means of experimental research, which is used to analyze the change law of ship resistance under the condition of a single factor. The coupling effects of multiple factors on the actual ship power are studied after the establishment of a mathematical relationship between the actual ship power and resistance on the basis of the response surface method. The research results show that: (1) there is an obvious positive correlation between ship resistance and speed, which matches the change law of the exponential equation. Compared with ship appendages, displacement and speed have the greatest influence on resistance. (2) According to the correlation analysis, the maximum correlation coefficient between ship speed/resistance and power is 0.99, and the correlation coefficients between displacement/resistance and power are 0.93 and 0.88, respectively. However, the correlation coefficients between ship appendages and resistance and power are only 0.23 and 0.14, respectively. (3) The actual ship power and speed, displacement, and appendages form a quadratic polynomial relationship. The multi-factor interaction analysis results show that speed and displacement have the greatest influence on the actual ship power. The research results have a certain guiding significance for ship design.

In this paper, the results obtained from a series of parametric analyses, where the influence that geometric and mechanical parameters have in the structural response of existing vernacular cob walls within an Irish context, are presented. A design of experiments using central composite designs was implemented along with analysis of variance following two computational approaches, namely, the finite element method and kinematic limit analysis. As results, a series of response surfaces and parametric equations with which it is possible to compute safety factors and collapse multipliers (within the range of values studied) are provided. Based on the results obtained, it could be concluded that traditional cob walls in Ireland are very robust. Relatively high acceleration values, unlikely to happen in a low seismic hazard region such as Ireland, would be needed to start the collapse mechanisms studied or cause yielding in typical vernacular cob walls. Furthermore, the equations generated with the refined regression models can be used by practitioners as a first approach to estimate the safety levels of existing cob buildings with similar characteristics.

Additive manufacturing (AM) of metallic materials is increasingly being adopted in numerous sectors, such as biomedicine, aerospace or automotive industries, due to its versatility in the creation of complex geometries and the minimisation of material waste when compared to traditional subtractive methods. In order to ensure a reliable operation of these parts, however, an in-depth study of the effect of additive manufacturing on mechanical properties, including tensile, fatigue and fracture resistance, is necessary. Among the vast number of methods and materials, this project is focused in one of the most promising techniques for the industry: Selective Laser Melting (SLM) for the production of a tools steel, in particular C300 steel components for the automotive sector. The main objective of this paper is to optimise some of the key parameters in the printing process, such as laser power, laser speed and hatch spacing. These variables are essential to obtain parts with good resistance. To that purpose, tensile tests were performed in 3D printed specimens, and then elastoplastic properties were extracted, organised and analysed through a design of experiments for the subsequent output fitting using the response surface methodology.

In the present study, the implementation of multi-blade profiles in a Savonius rotor was evaluated in order to increase the pressure in the blade’s intrados and, thus, decrease motion resistance. The geometric proportions of the secondary element were determined, which maximized the rotor’s performance. For this, the response surface methodology was used through a full factorial experimental design and a face-centered central composite design, consisting of three factors, each with three levels. The response variable that was sought to be maximized was the power coefficient (CP), which was obtained through the numerical simulation of the geometric configurations resulting from the different treatments. All geometries were studied under the same parameters and computational fluid dynamics models through the ANSYS Fluent software. The results obtained through both experimental designs showed a difference of only 1.06% in the performance estimates using the regression model and 3.41% when simulating the optimal proportions geometries. The optimized geometry was characterized by a CP of 0.2948, which constitutes an increase of 10.8% in its performance compared to the profile without secondary elements and of 51.2% compared to the conventional semicircular profile. The numerical results were contrasted with experimental data obtained using a wind tunnel, revealing a good degree of fit.

The development of a carbon-fiber-reinforced plastic (CFRP) part is carried out by utilizing many experimental results in deciding the design. For this reason, the development period of a CFRP structure is long and an obstacle for commercialization. In this paper, multiple regression analysis is used to derive a response surface that estimates the generated load using the shape parameters of a corrugated collision energy absorbing structure to shorten the development period. To obtain the response surface, we conducted a quasistatic crushing experiment by using the length of linear portions (pitch) and the number of stacks (thickness) of a corrugated shape as parameters. When progressive crushing mode is observed, energy absorption efficiency decreases with the increase in pitch, and increases with the increase in the number of stacks. To discuss how energy absorption efficiency changes, a comparison examination is conducted using the derived response surfaces. Results indicate that specifications with high energy absorption efficiency can be accurately selected using the response surface of primary expression. In addition, differences in deformation mode were due to the influence of the stress at the corner portion of a part.

The coagulating properties of wood vinegar from para rubber wood, bamboo, and coconut shell used as a substitute for acetic acid in the production process of natural rubber (NR) sheets were investigated and considered. For the dirt and volatile content, the tensile strength at break, the percentage of elongation at break, and the 300% modulus, the results showed that the types of wood vinegar coagulants were not significantly different from acetic acid. However, the Mooney viscosity and plasticity retention index (PRI) properties were significantly different from those of acetic acid. The NR sheet temperature increased rapidly during the first hour after the drying process started due to heat transfer from the hot air. Afterward, the temperature of the NR sheet samples began to stabilize. When the drying process started, the drying temperature was increased, so the trend was reducing the drying time. For the yellowness index (YI) value, the increase in the YI value was related to the type of coagulating material, the increase in the airspeed, and the drying temperature. The dried sheet samples using para rubber wood vinegar as the coagulating material had a color value at the same level as acetic acid and the referent. However, the bamboo and coconut shell wood vinegars were at a lower level. In comparing the YI value data between the experimental results and prediction values, the second-degree model had a better fit in prediction than the zero-degree and first-degree models. This result was confirmed by the higher mean of the coefficient of determination. The dried sheet product coagulated by using wood vinegar had fungus growth prior to supplying it to the customer.

With the recent rise in importance of environmental issues, research on micro hydropower, a kind of renewable energy source, is being actively conducted. In this study, a micro tubular propeller turbine was selected for study of micro hydropower in pipes. Numerical analysis was conducted to evaluate the performance. Response surface methodology using design of experiments was performed to efficiently investigate the effect of the blade leading and trailing edge elliptic aspect ratios on the performance. The trailing edge configuration was found to be more related to the performance, because of the drastic pressure variation due to the stagnation point formed, regardless of the leading edge configuration. To improve the performance, a NACA airfoil was introduced. The results show that the flow became more stable than the reference model, and the efficiency was increased by 2.44%.

The size distribution and total particle mass concentration (TPMC) of smoke particles from para rubber wood (Hevea brasiliensis) combustion in the ribbed smoked sheet (RSS) process were studied. In this experiment, temperature data values of para rubber wood combustion were recorded at 500 mm above the base of the fire by K-type thermocouples. The wood moisture content and wood combustion period were used to find and improve an equation of smoke particle size distribution (SPSD) and TPMC by the response surface method (RSM). An eight-stage Andersen air sampler and a high-volume sampler were used to measure and calculate SPSD and TPMC, respectively. Resulting data in this experiment showed that TPMC ranged from 3.12 to 77.42 mg/m3. SPSD was single mode in which MMAD, mass median aerodynamic diameter, ranged from 0.64 to 1.27 microns for para wood with moisture content ranging from 31.5 to 89.7% dry weight basis. The combustion period and moisture content of para wood have a direct effect on the change of temperature data above the base of the fire and the TPMC and MMAD values. For predicting TPMC and MMAD values by the para wood moisture contents in each combustion period, the results found that the second-degree model was a better plot than the first-degree model, confirmed by higher values of the coefficient of determination (R2).