Search

The transport phenomena of Casson nanofluid flow between two parallel disks subject to convective boundary conditions are analyzed in this paper. The mathematical model incorporates the impact of thermophoresis and Brownian motion since the Buongiorno's nanoliquid model is adopted to characterize the nanoliquid's transport features. The appropriate similarity transformations are applied to obtain the resulting nondimensional ordinary differential equations from the basic governing equations. The resulting ordinary differential equations and the associated boundary conditions are solved analytically by adopting the homotopy perturbation technique. Further, a statistical experiment is conducted to identify notable flow parameters which cause significant impact on the heat transfer rate. The characteristics of critical pertinent parameters on the flow field are graphically manifested. It is worth noting that the Casson nanofluid velocity escalates by augmenting the magnetic field parameter in the case of injection near the disks. Nanoparticle concentration is considerably diminished with an increment in thermophoresis parameter. In the cases of equal and unequal Biot numbers, the heat transfer rate is promoted with higher values of the Brownian motion parameter. Among the Casson fluid parameter, squeezing parameter and magnetic field parameter, the heat transfer rate discloses the highest positive sensitivity with the lowest value of the Casson fluid parameter. [ABSTRACT FROM AUTHOR]

In this study, the antimicrobial activity of silver nanoparticles (AgNPs L21, AgNPs L22) produced using aqueous extracts of the Laser trilobum harvested in 2021 and 2022 was optimized. The experimental design and optimization of antimicrobial activity were performed using the response surface method (RSM). Using RSM, independent variables, such as silver concentration, extraction time, and synthesis temperature, were optimized as a result of the inhibition zone diameter against Staphylococcus aureus, Escherichia coli, Salmonella Typhimurium, and Listeria monocytogenes. Based on the optimization results, the extraction time, silver concentration, and temperature for AgNP L21 and L22 synthesis were determined to be 60 min, 5 mM, and 25 °C, respectively. When the XRD and TEM results of the nanoparticles synthesized under optimal conditions were evaluated, it was determined that the AgNPs were spherical in shape and had an average size of 30 ± 12 nm. Our study revealed that the year of harvest is unimportant for nanoparticles synthesized from L. trilobum, using a cheap and simple method that does not require toxic substances. Owing to the antimicrobial activity of nanoparticles produced under optimal conditions, it is possible to biocontrol and prevent contamination by these bacteria in food science and industry. [ABSTRACT FROM AUTHOR]

Thermal link is an important carrier used to transfer the cooling capacity and suppress the temperature fluctuation in cryostat. To balance these two points, it is usually necessary to find the optimum thermal link parameters. This paper establishes a model for the cryocooler cold head-thermal link-second flange based on a cryostat. Utilizing the response surface method, response equations correlating thermal link parameters with the temperature and its fluctuations of the second stage flange are developed at the lowest temperature of cryocooler. Through dual-objective optimization of cooling capacity transfer and temperature fluctuations at the second flange, the optimal thermal link parameters are determined and experimentally validated based on predicted results. The experimental and predicted values show good agreement with an error of 2 %. The optimized thermal link led a minor temperature increase and a significant temperature fluctuation reduction, decreasing from 230mK at the cold head to 2.900mK at the second flange, achieving a 98.74 % reduction. Furthermore, compared with non-optimization structure, the optimization one has further lowered the temperature fluctuation at the second flange from 4.000mK to 2.900mK with 27.5 % improvement. These results show that the present methods are reliable and useful to help to realize highly stable low-temperature environment in cryostat. [ABSTRACT FROM AUTHOR]

Using aeolian sand (AS) for goaf backfilling allows coordination of green mining and AS control. Cemented AS backfill (CASB) exhibits brittle fracture. Polypropylene (PP) fibers are good toughening materials. When the toughening effect of fibers is analyzed, their influence on the slurry conveying performance should also be considered. Additionally, cement affects the interactions among the hydration products, fibers, and aggregates. In this study, the effects of cement content (8wt%, 9wt%, and 10wt%) and PP fiber length (6, 9, and 12 mm) and dosage (0.05wt%, 0.1wt%, 0.15wt%, 0.2wt%, and 0.25wt%) on fluidity and mechanical properties of the fiber-toughened CASB (FCASB) were analyzed. The results indicated that with increases in the three aforementioned factors, the slump flow decreased, while the rheological parameters increased. Uniaxial compressive strength (UCS) increased with the increase of cement content and fiber length, and with an increase in fiber dosage, it first increased and then decreased. The strain increased with the increase of fiber dosage and length. The effect of PP fibers became more pronounced with the increase of cement content. Digital image correlation (DIC) test results showed that the addition of fibers can restrain the peeling of blocks and the expansion of fissure, and reduce the stress concentration of the FCASB. Scanning electron microscopy (SEM) test indicated that the functional mechanisms of fibers mainly involved the interactions of fibers with the hydration products and matrix and the spatial distribution of fibers. On the basis of single-factor analysis, the response surface method (RSM) was used to analyze the effects of the three aforementioned factors and their interaction terms on the UCS. The influence surface of the two-factor interaction terms and the three-dimensional scatter plot of the three-factor coupling were established. In conclusion, the response law of the FCASB properties under the effects of cement and PP fibers were obtained, which provides theoretical and engineering guidance for FCASB filling. [ABSTRACT FROM AUTHOR]

The two-phase fluid flow in the Heavy-duty diesel (HDD) engine water jacket coolant can greatly reduce the thermal load of the cylinder head. In this experimental work, the characteristic of two-phase fluid flow in a transparent Plexiglas channel using C2H6O2- H2O (50%–50%) is investigated. Gray cast iron surfaces were selected as the heated surfaces to simulate the material of the HDD-cylinder head. Operating conditions of the HDD- engine (i.e. Vinlet from 0.46 to 2.0 m/s, Psystem from 1 to 2 bar and Tinlet from 70 to 110°C) are optimized using Response Surface Method (RSM) within the framework of the Central Composite Design (CCD) model. The outputs indicate: the onset of nucleate boiling (ONB) temperature increases by about ≈ 11.92% when the pressure changes from 1 to 2bar. By reducing the inlet temperature (from 70 to 110℃), the effect of superheating disappears around the bubble, so to reach the non-linear (i.e. two-phase region) area, the heat flux must be increased between 10 to 15 kW/m² to observe the ONB point. The cooling system pressure at low velocities (i.e. < 1m/s) should be considered in such a way that the saturation temperature of the fluid is about 35 to 50℃ lower than the HDD-engine wall temperature. Instead, at high velocities (i.e > 1m/s) this temperature difference between the fluid saturation temperature and the wall temperature is about 55 to 85℃. [ABSTRACT FROM AUTHOR]

ABSTRACT This study aimed to investigate the influence of semicircular bend (SCB) specimen size (R), loading mode (Me), and loading rate (Lr) on fracture resistance indicators, namely, fracture work (Wf), fracture energy (Gf), and fracture strength (Kf), of asphalt concrete at three different temperatures (−30°C, −20°C, and 10°C). Using Minitab software, response surface methodology (RSM) under central composite design (CCD) was employed to design experiments and develop predictive models for Wf, Gf, and Kf in terms of R, Me, and Lr at each temperature. The results demonstrated that the RSM models accurately predicted the fracture test data for all temperatures. The analysis of variance (ANOVA) revealed that R, Me, and Lr significantly influenced Wf, Gf, and Kf at each temperature, whereas the square terms R2, Me2, and Lr2 were not significant. The significance of two‐way interaction terms varied across different responses and temperatures. Overall, the experiments conducted at −30°C, −20°C, and 10°C indicated that varying R, Lr, and Me had notable effects on Wf, Gf, and Kf. Increasing R and Me while decreasing Lr resulted in an increase in Wf and Gf. Furthermore, Kf exhibited a direct relationship with R and Lr but an inverse relationship with Me. [ABSTRACT FROM AUTHOR]

Methane hydrates is regarded as an important alternative energy in the future. Due to the complexity of marine environment, the mechanical parameters and initial stress state of formation have great uncertainties which can affect the wellbore stability in hydrate exploitation. In this study, a new time-dependent analytical model is proposed, considering the influence of hydrate dissociation on the mechanical properties and the partial coupling among pore pressure/temperature/mechanical field. The analytical solutions are verified and validated by numerical solutions. Based on the analytical solution and Mogi-Coulomb failure criterion, the reliability of wellbore stability during drilling in hydrate exploitation is analyzed by the Response Surface Method. Through the reliability analysis, the probability of wellbore instability increases and the safe drilling fluid pressure window range is narrowed with time, and finally tended to be stable at t = 12 h. Hydrate dissociation would lead to a more narrowed pressure window range, about by −38.75%. The most significant parameter whose uncertainty affects the instability probability is initial in-situ stress, followed by the initial internal friction angle and Biot's coefficient. [ABSTRACT FROM AUTHOR]

[Objective]Taking tobacco as experiment material, extraction process of tobacco polypeptide and its antioxidant activity was studied in this research. [Method]Tobacco polypeptide was extracted by enzyme-assisted water extraction and alcohol precipitation. Single factor test was used to investigate the effects of enzyme addition, enzymolysis pH, enzymolysis time, extraction temperature and substrate concentration on the extraction rate of tobacco polypeptide. The optimal extraction process of tobacco polypeptide was determined by response surface method. The scavenging activity of tobacco polypeptide on DPPH and hydroxyl radicals was detected. [Result]The optimal extraction process for tobacco polypeptide was as follows (based on 1 g tobacco sample):enzyme addition 4 200 U, enzymolysis pH 8. 2, enzymolysis time 2. 5 h, extraction temperature 49 ℃ and the substrate concentration 4. 2%. Under the optimized extraction process, the extraction rate of tobacco polypeptide was 88. 23 mg / g. The scavenging rates of DPPH and hydroxyl radicals of the tobacco polypeptide were 83. 09% and 73. 84%, respectively. Tobacco polypeptide was of a certain antioxidant capacity. [Conclusion] This study provides a certain theoretical basis and technical guidance for the medicinal value of tobacco leaves and the drug development of tobacco peptides. [ABSTRACT FROM AUTHOR]

Highlights The formation of cracks and their growth is an issue of concern in structural applications incorporating thin metal sheets. Adhering cracked region with a patch of composite material has proved effective in repairing cracks. Determining an optimum configuration of composite patch is still a challenge as a shorter patch may not be effective and a larger patch leads to wastage of resources. An appropriate methodology is required for specifying an optimum patch configuration in terms of its length, width, and thickness. The work presented prescribes a methodology for obtaining an appropriate combination of geometrical parameters of the composite patch. The computational tools like finite element analysis and response surface method have been incorporated. This is an extensive work consisting of a number of iterations of numerical analyses carried out for different combinations of the length and width of the patch. The results were also obtained for three different patch thicknesses in which the number of plies were increased from a single ply to three plies. The optimum size was obtained for each of the three patch thicknesses. Finally, a methodology for obtaining the most appropriate patch configuration based on the practical constraint of a small available area is prescribed. The crack repair in a thin structural sheet using fiber reinforced polymer composite patch separates at the interface. The optimum size of the patch needs to be used for an effective repair. The work consists of a combination of experiments and numerical simulations using finite element analysis. Response surface methodology is employed in this optimization study. [ABSTRACT FROM AUTHOR]

To reduce carbon emissions, hydrogen is a clean energy as fuel to co-combustion with natural gas. This experimental work focuses on studying the effects of hydrogen addition to methane on combustion performance and emissions in non-premixed coaxial burners, establishing performance prediction models and optimizing operation conditions involving fuel velocity, hydrogen blending ratio and equivalence ratio. The global sensitivity and analysis of variance were adopted to quantify the contributions of independent variables on the output responses of temperature, O 2 , NO, CO and CO 2 emissions. The hydrogen blending ratio is the most influential parameter, whose total effects of NO and CO 2 emissions are 64.6% and 83.5%, respectively. The equivalence ratio is not significant to NO and CO 2 emissions, and the adjusted determination coefficient of the reduced prediction model is 0.9707 and 0.9360, demonstrating a better goodness of fit. Based on the response surface model and particle swarm optimization algorithm, a Pareto was solved showing NO and CO 2 emissions decrease by 42.0%–73.6% and 60.8%–89.5%, and peak temperature in the chamber centerline increases by 1.02%–3.61%. The research results provide a profound guide to predict and optimize combustion performance and emissions for methane-hydrogen non-premixed flame. [Display omitted] • Prediction models of CH 4 –H 2 non-premixed burner were built by response surface method. • Total effects of hydrogen blending ratio on NO and CO 2 emissions are 64.6% and 83.5%. • Equivalence ratio is not significant to flue gas temperature, NO and CO 2 emissions. • A Pareto set was obtained by optimizing flame temperature and pollutants via PSO. • Peak temperature increases by 2.30%, NO and CO 2 decrease by 59.4% and 78.3%. [ABSTRACT FROM AUTHOR]

In three-dimensional free-bending forming (3D-FBF), the tube is not overly constrained, and the plastic deformation behavior and forming quality of the bent tube are significantly affected by the critical structure of the forming die lining. However, the effects of die-lining structural parameters on the tube quality, and a method to determine the combination of die-lining structural parameters is yet to be devised. This study aims to propose a new framework that allows one to understand the effects of various die-lining structural parameters on tube quality and to propose the best combination of die-lining structural parameters. First, finite-element modeling is performed to simulate 3D-FBF and examine the effects of individual die-lining structures on the quality of tube formation. The simulation results show that the deformation-zone length and die gap are positively correlated with the tube-section distortion and wall-thickness variation, whereas it shows an opposite trend with respect to the bending radius. Additionally, the lining chamfer radius of the bending die and the guide lining chamfer radius minimally affect the tube forming quality. Subsequently, the optimal die-lining structure is obtained using the response-surface method. The tube cross-sectional distortion rate reduced from 2.73 to 2.53% after the die lining is optimized. Additionally, the average inner-wall thickness reduced to 1.06 mm, whereas the average outer-wall thickness increased to 0.97 mm. This paper proposes a method for optimizing the forming-die-lining mechanism and for improving the tube forming quality in 3D-FBF. [ABSTRACT FROM AUTHOR]

This work aims to analyze the effects of the main process parameters of fused filament fabrication (FFF) on the mechanical properties and part weight of 3D-printed thermoplastic polyurethane (TPU). Raster angle (RA), infill percentage (IP), and extruder temperature (FFF) in the ranges of 0–90°, 15–55%, and 220–260 °C, respectively, were considered as the FFF input parameters, and output variables part weight (PW), elongation at break (E), maximum failure load (MFL), ratio of the maximum failure load to part weight (Ratio), and build time (BT) were considered as responses. The Response Surface Methodology (RSM) and Design of Experiments (DOE) were applied in the analysis. Subsequently, the RSM approach was performed through multi-response optimizations with the help of Design-Expert software. The experimental results indicated a higher maximum failure load is achieved with an increased raster angle and decreased extruder temperature. ANOVA results show that ET has the most significant effect on elongation at break, with elongation at break decreasing as ET increases. The raster angle does not significantly affect the part weight of the TPU samples. The ratio of the maximum failure load to part weight of samples decreases with an increase in IP and ET. The results also indicated that the part weight and build time of FFF-printed TPU samples increase with an increase in IP. An ET of 220 °C, RA of 0°, and IP of 15% are the optimal combination of input variables for achieving the minimal part weight; minimal build time; and maximum elongation at break, maximum failure load, and ratio of the maximum failure load to part weight. [ABSTRACT FROM AUTHOR]

The proposed method involves the utilization of a strip roll-forming technique to fulfill the specific requirements for constructing large-scale structures in orbit and space station trusses during extraterrestrial exploration. This involves progressively rolling out a metal strip with an L+V-shaped locking edge through multiple passes of forming rolls featuring different section shapes. The process of helical locking enables the formation of a slender, spiral-shaped tube, which can be utilized for the in-orbit assembly of exceptionally large structures. The proposed approach introduces a two-step optimization method to enhance the maximum stress, equivalent plastic strain, and wrapping torque of roll-forming L+V cross-sections and wrap-forming helical tubes. The optimized sample points in the second step are established based on the optimal roll distance and roll gap obtained in the first optimal step, resulting in the determination of the optimal folding height and V-shaped angle of the L+V strip cross-section after optimization. The design of the strip wrapping configuration that follows is highly dependent on these four parameters. [ABSTRACT FROM AUTHOR]

Microbes within a consortium exhibit a synergistic interaction, enhancing their collective capacity to perform functions more effectively than a single species, especially in the degradation of keratin-rich substrates. To achieve a more stable and efficient breakdown of chicken feathers, a comprehensive screening of over 9,000 microbial strains was undertaken. This meticulous selection process identified strains with the capability to degrade keratin effectively. Subsequently, antagonistic tests were conducted to isolate strains of fungi and bacteria that were non-antagonistic, which were then used to form the artificial microbial consortia. The optimal fermentation conditions for the keratinophilic microbial consortia were determined through the optimization of response surface methodology. The results revealed that 11 microbial strains–comprising of 4 fungi and 7 bacteria–were particularly proficient in degrading chicken feathers. The artificially constructed microbial consortia (AMC) comprised two bacterial strains and one fungal strain. The optimal conditions for feathers degradation were identified as a 10 g/L concentration of chicken feathers, a 2.6% microbial inoculation volume and a fermentation fluid pH of 9. Under these conditions, the degradation rate for chicken feathers reached a significant 74.02%, representing an 11.45% increase over the pre-optimization rate. The AMC developed in this study demonstrates the potential for efficient and economical process of livestock and poultry feathers. It provides innovative insights and a theoretical foundation for tackling the challenging degradation of keratin-rich materials. Furthermore, this research lays the groundwork for the separation and purification of keratins, as well as the development of novel proteases, which could have profound implications for a range of applications. [ABSTRACT FROM AUTHOR]

This paper develops a new approach for reliability-based design (RBD) of tunnel face support pressure from a quantile value perspective. A surrogate model is constructed to calculate the collapse pressures of the random samples generated by a single run of Monte Carlo simulation (MCS). The cumulative distribution function (CDF) of the collapse pressure is then obtained and the support pressure aiming at a target failure probability is chosen as the upper quantile value of the collapse pressures. The proposed approach does not require repetitive reliability analyses compared to the existing methods. Moreover, a direct relationship between the target failure probability and the required support pressure is established. An illustrative example is used to demonstrate the implementation procedure. The accuracy of the reliability-based support pressures is verified by direct MCS incorporating with three-dimensional numerical simulations. Finally, the influencing factors, including the sample size of MCS, the correlation coefficient between random variables, the choice of experimental points, and the surrogate model, are investigated. This method can play a complementary role to available approaches due to its advantages of simplicity and efficiency. [ABSTRACT FROM AUTHOR]

Cage-typed sleeve control valve (CSCV) is the key basic equipment in direct coal liquefaction projects. The working condition of CSCV has the characteristics of high-pressure difference, high velocity, and high solid content. There is a general issue of liquid–solid two-phase erosion wear in CSCV, which can easily lead to the failure of the internal structure in the valve cage. Therefore, it is necessary to study erosion wear characteristics of internal structures in the valve cage. Considering the real conditions of erosion wear in the valve cage, a simplified T-shaped flow path is designed, and the precision of both the liquid–solid two-phase flow model and the erosion prediction model is validated. The flow characteristics and erosion wear characteristics in the T-shaped flow path under different working conditions are studied. Based on the simulation results of different structural parameters and boundary conditions, the erosion wear of the T-shaped flow path is predicted and calculated by the response surface method. Subsequently, the prediction formula for the maximum erosion rate is derived. The formula enables the swift determination of optimal structural parameters for the flow path, aiming to mitigate damage to the valve caused by erosion wear. This work can quickly predict the erosion wear rate of the key areas in the valve cage, which can provide a certain reference value for the life prediction and structural optimization of CSCV, and it can also benefit the safety and maintenance of the coal liquefaction system. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Condiment is the property of China Condiment and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrometallurgy of China is the property of Hydrometallurgy of China Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrometallurgy of China is the property of Hydrometallurgy of China Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Removal of Lindane pesticide from the environment is of utmost requirement. Besides, production of adsorbents to remove Lindane releases other pollutants and greenhouse gases into the environment. Therefore, in this study, the application of environmentally friendly low-cost, and readily available Halodule uninervis seagrass powder (SG) as an adsorbent is reported for the removal of Lindane from contaminated water. The environmental footprint of SG production was investigated using life cycle inventory (LCI). To investigate the adsorption parameters and reduce the wastage associated with the one variable at a time (OVAT) conventional investigation approach, response surface method (RSM) and artificial intelligence (AI) approaches were engaged. However, to investigate the isotherm and adsorption kinetics, OVAT parameter optimization was conducted. It is found that 16 h and 24 °C were the optimum time and temperature, respectively, and pH does not affect Lindane removal. Pseudo-second-order kinetics and Freundlich isotherm models were found the best to describe Lindane adsorption onto SG which was seen to be exothermic (− 29.17 kJ mol−1). The spent SG was found to be reusable in the synthetic wastewater with a value of 74% removal efficiency. XPS characterization results indicated that Lindane is physically adsorbed onto SG. LCI data showed that SG adsorbent has promising performance with very low negative environmental impacts. [ABSTRACT FROM AUTHOR]

The renewable nature and exceptional strength-to-weight ratio of bamboo have led to numerous studies on incorporating bamboo fiber (BF) in composite fabrication. The mechanochemical BF extraction process used to produce high-quality micron fibers still faces limitations such as low percentage (%) yield and hydrophilicity. Moreover, the bead formation during BF extraction reduces the % yield and complicates the fiber separation process. This study introduces an innovative method for extracting BF with fewer fiber beads to improve the % yield. The process parameters were optimised using the response surface method (RSM) having a face-centred central composite design (FCCD). The optimal fiber extraction conditions were 80.61 min of boiling with 15% NaOH concentration and stirring at 1800 rpm. The most influencing parameter was identified using analysis of variance (ANOVA) and parametric analysis. Diisopropanolamine (DIPA) was used to graft amine functional groups on BF's surface to increase their hydrophobicity, whose confirmation was obtained using water retention value (WRV) analysis. Fourier-transform infrared spectroscopy (FTIR) validates the surface modification of BF. The crystallinity of BF appeared to be minimally affected by the DIPA modification, as confirmed by the X-ray diffraction (XRD) analysis. Field-emission scanning electron microscopy (FESEM) analysis of BF and DIPA-modified BF reveals well-separated fibers with minimal cellulose surface peeling after surface treatment. Thermogravimetric (TG) and differential thermogravimetric (DTG) analyses were also accomplished to validate the improved thermal stability of BF by amine-based treatment. [ABSTRACT FROM AUTHOR]

Aluminum electrolysis spent cathode carbon (SCC), as typical solid hazardous waste, poses significant environmental risks. Harmless treatment of SCC and recycling of its carbon component are important research areas. In this study, SCC was subjected to microwave hydrothermal acid leaching to remove harmful components, followed by the production of high-quality graphite via iron-catalyzed graphitization. The effects of reaction temperature, heating time, and catalyst loading on the graphitization conversion of SCC were investigated. The catalytic graphitization process of SCC was optimized using the response surface method. The results show that when the reaction temperature is 1520 °C, the heating time is 85.24 min, and the catalyst loading is 46.15 wt%, the graphitization degree of the sample is 97.61 %. The samples prepared under the optimal conditions were characterized using XRD, Raman, SEM, and TEM. The results reveal that the catalytic graphitization process significantly influences the conversion of microcrystalline structures in SCC into graphite structures. The iron-catalyzed transformation of microcrystalline carbon was analyzed to elucidate the graphitization transformation mechanism. This study offers an effective pathway for the high-value utilization of SCC. It also serves as a technical reference for the catalytic graphitization conversion of carbon materials. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To achieve an aerodynamically efficient design of fuselage for bioinspired unmanned aerial vehicles (UAV), the development of a systematic method is of paramount need. This work presents a multiobjective optimization study for shape parameterization of a 2D fuselage of foldable flapping wing UAV in low Reynolds number (2e05) flight conditions. The novelty of the research work lies in integrating S1223 airfoil characteristics for predicting the efficient shape design of the fuselage. This paper offers four sections; (i) the validation of the ANSYS Fluent model with experiment, (ii) the exploration of design variables using Design of Experiment (Sparse Grid Initialization), (iii) the implementation of response surface method (Genetic Aggregation) to know about dimensional sensitivity among independent and dependent variables and (iv) the application of multiobjective optimization method i.e. NSGA II to optimize the drag and lift coefficient. To identify the superiority, a comparative study between the original and optimized fuselage is presented considering many parameters like pressure contours, velocity contours, pressure coefficients, and streamlines representations. It is evident from various results that the 2D optimum shape significantly minimizes the drag coefficient and increases the lift coefficient. This work also makes room for 3D shape optimization, which helps in prototype fabrication for real-time flight conditions. [ABSTRACT FROM AUTHOR]

This study focused on optimizing the process of CNC machining to enhance productivity and product quality of surface finish Ra via the process parameters of the cutting speed (vc), feed rate (vf), and cutting depth (doc). Experimentation was performed on workpieces of AA-6061 to investigate the response Ra through variation of the process parameters to analyze their best fit using RSM with 2³ full factorial designs L-8 of DOE. The analysis of variance (ANOVA) was then used to find the major contributors among them that were responsible for the Ra. Based on the result, better Ra was obtained at 0.103 µm using the best fit of vf (150 mm/min), vc (220 m/min), and doc (0.1 mm). ANOVA shows vf contributed better Ra followed by vc and doc respectively. In addition, the level of Ra's was analyzed through contour plots represented by different colours. It continued to analyze the effect of the process parameters via the main effects plot, Pareto chart, and the contour plot in the predictive desirability model, which indicated that the plots and chart confirmed the vf had more influence compared to others. The study confirmed that the low-level parameters provided better Ra to be used for polishing. [ABSTRACT FROM AUTHOR]

The aims of the present stud were to optimize fermentation parameters of seedless wampee wine using response surface methodology (RSM) and evaluate the changes in flavor metabolites during fermentation. Seedless wampee wine of optimal sensory quality was produced using an inoculum concentration of 0.6%, initial sugar levels of 200 g/L, a fermentation temperature of 22 °C, and a fermentation period of 9 days. Then the flavor compound profiles (amino acids, organic acids and volatile aroma compounds) of seedless wampee wine during the fermentation under optimal conditions were analyzed using high performance liquid chromatography (HPLC) and gas chromatography–mass spectrometr (GC-MS). The main fermented phase of fermentation resulted in fluctuations in both total amino acids and organic acids, with stabilization occurring later on. A total of 54 volatile components, including esters, alcohols, terpenes, and acids, were putatively identified. Terpenes were the primary drivers of the flavor characteristics of seedless wampee. The rise of esters and decline of terpenes have the potential to significantly alter the flavor of wine during fermentation. These results would contribute to the further development of seedless wampee wine. [ABSTRACT FROM AUTHOR]

This work involved the preparation of pristine and iron nanoparticle-loaded biochar from a water chestnut shell to remove diclofenac sodium (DCF) containing effluent of pharmaceutical origin. To create suitable forecasting equations for the modelling of the DCF adsorption onto the adsorbent, response surface methodology (RSM) was used. The parameters, e.g. pH, adsorbent mass, DCF concentration and contact time, were used for the modeling of adsorption. The RSM model predicts that for 98.0% DCF removal, the ideal conditions are pH 6, an adsorbent dose of 0.5 g L−1, and a contact time of 60 min with an initial adsorbate concentration of 25 mg L−1 at 303 K. The maximum capacity deduced from the Langmuir model was 75.9 mg g−1 for pristine water chestnut shell biochar (pWCBC) and 122.3 mg g−1 for magnetically modified nano-Fe2O3 biochar (mWCBC). Under equilibrium conditions, the Langmuir model was the best-suited model compared to the Temkin and Freundlich models. The adsorption data in this investigation efficiently fitted the pseudo-second-order model, emphasizing that chemisorption or ion exchange processes may be involved in the process. The WCBC demonstrated recyclability after 10 cycles of repeated adsorption and desorption of DCF. A combined coagulation adsorption process removed COD, NH3–N, NO3−, PO43−, and DCF by 92.50%, 86.41%, 77.57%, 84.54%, and 97.25%, respectively. This study therefore shows that coagulation followed by adsorption onto biochar can be a cost-effective substitute for conventional pharmaceutical wastewater treatment. [ABSTRACT FROM AUTHOR]

Abstract\nNOVELTY STATEMENTThe combined microbial-plant remediation has increasingly been used to remediate heavy metal-contaminated soil. Some microorganisms could enhance phytoremediation efficiency by solubilizing heavy metal and improve plant growth by producing phytohormones in the heavy metal contaminated soils. In the present study, a strong cesium (Cs)-tolerant fungal strain Paecilomyces lilacinus was identified from soil microorganisms contaminated with Cs, and the enrichment conditions for Cs were optimized. Furthermore, the effects of the A10 fermentation solution on the growth of Indian mustard (Brassica juncea L.) seedlings were investigated. The results indicated that the optimal combination of factors consisted of a culture temperature of 28 °C, pH7.0, initial concentration of Cs at 5.91 g·L−1. The maximum enrichment of Cs in the A10 was up to 75.36 mg·g−1 DW. In addition, the enrichment of Cs in Indian mustard was significantly enhanced by the application of the A10 fermentation solution, and the growth of Indian mustard was promoted under Cs stress. The present study has expanded the repertoire of microbial resources available for facilitating the Cs contaminated soil, thereby enhancing its applicability in the phytoremediation strategies.Recently, cesium (Cs) pollution has become a global environmental problem. Although much attention has been paid to combined microbe-plant remediation, there is still a lack of microbial strains with efficient Cs adsorption capacity to assist phytoremediation. The present study identified a new Cs accumulation fungus that effectively enhances the growth of Brassica juncea L. under Cs stress. In a word, the findings of this study have expanded the repertoire of microbial resources available for facilitating the Cs contaminated soil, thereby enhancing its applicability in the phytoremediation strategies. [ABSTRACT FROM AUTHOR]

In this research, graphene oxide (GO) as an adsorbent was used to remove norfloxacin and ceftriaxone antibiotics from aqueous solutions. All environmental factors affecting removal (e.g., pH, adsorbent mass, contact time, and concentration) were optimized in a discontinuous system. The design of experiments and the optimization of variables were carried out using the response surface method (RSM). The results of the analysis of variance (ANOVA) and the regression coefficients of the quadratic terms indicated that the responses were significantly affected by all the studied variables (P < 0.05). Also, the quadratic polynomial model results corresponded to empirical data with a high coefficient of determination (i.e., R² > 0.99 for both antibiotics). Besides, the adjusted R² (R²-adj >0.98 for both antibiotics) was close to R² values, indicating a good and acceptable statistical model. According to the results, the optimal removal of antibiotics by GO occurs in conditions of pH of 8, 0.034 g of the adsorbent mass, a sonication time of 20 min, and a concentration of 25 mg L-1. In these conditions, the maximum removal efficiencies of ceftriaxone and norfloxacin were equal to 95.87% and 98.64%, respectively. GO was recovered in five adsorption/desorption processes, and the removal efficiency declined very slightly after using the adsorbent for five cycles. Therefore, it is concluded that GO is an efficient and acceptable adsorbent for removing ceftriaxone and norfloxacin from aqueous environments. [ABSTRACT FROM AUTHOR]

The Kcggin-tjrpc P-Mo-W polyoxometalatc(POM) with ionic bquids(ILs) have been facilcly supported on cellulase acetate fiber((2A) through the impregnation method, obtaining a kind of molding catalytic material for the extractive oxidative desulfurization(E()1)S)・ I'hc response surface design experiment was used to investigate the c fleets of temperature, catal)-st mass, oxygrn-sulfur ratio and poly acid loading on the desulfurization reaction. Research has shown that the optimal dcsiiUiirization reaction conditions were: simulated diesel oil 25 mL, catalyst 0・ 16 g, temperature 63 4: , oxygen siilftir ratio 4. 8, polyac・ id loading 1. OS, 99.2% of 1)BT in simulated file I can be remmed after 2 h of reaction. [ABSTRACT FROM AUTHOR]

Taking ship vibration isolation systems as the research subject, the particle damper was applied to ship vibration isolation systems to study its vibration reduction performance. The energy dissipation mechanism of particle dampers is analyzed, and an energy dissipation calculation model is derived. The combined method of simulation and experimentation is employed to study the influence of parameters such as particle material, filling rate, particle diameter, and collision coefficient of restitution on the vibration reduction performance of particle dampers. The impact laws of these parameters are summarized, demonstrating that particle dampers can produce excellent vibration reduction performance when applied in ship vibration isolation systems, and reasonable parameter recommendations are provided. Response surface method (RSM) is used to fit an accurate energy dissipation prediction model and calculate the optimal performance parameters. This paper serves as a valuable reference for the parameter design, optimization, and practical engineering applications of particle dampers. [ABSTRACT FROM AUTHOR]

Agricultural environmental pollution needs to be reduced in our future. The biggest obstacles to preventing this situation are that agricultural inputs such as synthetic fertilizers increase product yield and scattered agricultural areas. This study involves the optimization of the production process of an easy-to-apply organic fertilizer with high nutritional value by subjecting bat guano, one of the valuable organic fertilizers, to anaerobic digestion together with cattle manure. Response surface method Box-Behnken design, a statistical model, was used for process optimization. The process input parameters were temperature, cattle manure, and bat manure, and the response value was considered as 2% total nitrogen. As a result of the optimization for a total nitrogen value of 2%, the optimum mixture ratio was determined as cattle manure 77.0448%, bat manure 12%, and temperature 40 °C. Analysis results showed that the addition of bat manure increased the N, P, K, and humic and fulvic acid values in the fertilizer. The study revealed that strong organic fertilizers can be used to increase the value of cattle manure organically. It also offers very promising results based on reducing agricultural pollution and ensuring agricultural sustainability. [ABSTRACT FROM AUTHOR]

To improve the resource utilization of dredged silt and industrial waste, this study explores the efficacy of using ground granulated blast furnace slag (GGBS), active calcium oxide (CaO), and sodium silicate (Na2O·nSiO2) as alkali activators for silt stabilization. Through a combination of addition tests, response surface method experiments, and microscopic analyses, we identified key factors influencing the unconfined compressive strength (UCS) of stabilized silt, optimized material ratios, and elucidated stabilization mechanisms. The results revealed the following: (1) CaO exhibited the most pronounced stabilization effect, succeeded by Na2O·nSiO2, whereas GGBS alone displayed marginal efficacy. CaO-stabilized silt demonstrated rapid strength augmentation within the initial 7 d, while Na2O·nSiO2-stabilized silt demonstrated a more gradual strength enhancement over time, attributable to the delayed hydration of GGBS in non-alkaline conditions, with strength increments noticeably during later curing phases. (2) Response surface analysis demonstrated substantial interactions among GGBS-CaO and GGBS-Na2O·nSiO2, with the optimal dosages identified as 11.5% for GGBS, 4.1% for CaO, and 5.9% for Na2O·nSiO2. (3) X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses clarified that the hydration reactions within the GGBS-Na2O·nSiO2 composite cementitious system synergistically enhanced one another, with hydration products wrapping, filling, and binding the silt particles, thereby rendering the microstructure denser and more stable. Based on these experimental outcomes, we propose a microstructural mechanism model for the stabilization of dredged silt employing GGBS-CaO-Na2O·nSiO2. [ABSTRACT FROM AUTHOR]

Rice straw is an important renewable resource. Under the circumstance of global resource shortage and energy shortage, it is of great significance to vigorously develop comprehensive utilization of straw. It is not only an important way to realize agricultural circular economy and low-carbon economy, but also involves sustainable development issues such as soil fertility, environmental security and efficient utilization of renewable resources in the entire agricultural ecosystem. Straw fiber ecological blanket has a good function of air permeability and water permeability, and has a significant positive effect on the ecological protection of soil surface microenvironment. Mechanical kneading is the key technology for the dismantling and optimization of agricultural waste straw fiber. In this study, the optimal process input is the spindle speed, hammer tooth clearance and material water content, and the output is the straw silk rate and calibrated unit productivity. An intelligent model was developed using Box-Behnken response surface method (RSM) to determine the functional relationship between input and output parameters. The three evaluation index models all have high reliability, and the determination coefficients are R 2 > 0.95 and R 2 > 0.94, respectively. The variance analysis of RSM regression model clarified that the influence of various factors on straw silk ratio was in the order of spindle speed > water content > hammer tooth clearance, and the linear relationship between spindle speed and straw silk ratio was increasing. The significant influence on the calibrated unit power productivity of the kneading machine is in the order of hammer tooth clearance > spindle speed > moisture content. When the hammer tooth clearance is constant, it decreases first and then increases with the spindle speed and straw moisture content. The results of factor interaction analysis showed that when the water content of straw was 40%, the spindle speed was 2 500 r/min, and the hammer tooth clearance was 13 mm, the silk ratio of rice straw was 96.75%. When the straw moisture content is 60%, the spindle speed is 2 300 r/min, and the hammer tooth clearance is 11.08 mm, the maximum calibrated unit power productivity is 29.96 kg/(kW·h). Mathematical model process parameters optimization: straw moisture content is 41.2%, spindle speed is 2 498 r/min, hammer tooth clearance is 12.84 mm. Under the combination of these parameters, the rice straw silk ratio is 96.93%, and the calibrated unit power productivity is 29.33 kg/(kW·h). Under optimized conditions, the proportion of fibers with length of 40～70 mm and > 70 mm showed an increasing trend, especially the fiber with length of > 70 mm increased by 120.55%. The proportion of fiber length-to-width ratio > 50～80 and > 80 increased from 17.39% and 6.52% to 38.64% and 16.01%, respectively. Ultra depth of field microscopy showed that the self-interweaving formability of kneaded straw fiber was significantly improved. The optimized mechanical kneading cost of straw fiber can be reduced by 27.50 yuan/t. The mechanical kneading technology strategy of the RSM model developed in this paper is effective for improving the decomposition rate of biomass straw and reducing the consumption of biomass straw, and can be widely used in the production of high-value agricultural products based on large fiber bundles of straw. The mechanical kneading technique strategy of the RSM model developed in this paper is effective for improving the decomposing silk rate and reducing the consumption of biomass straw, and can be widely used in the production of large-size fiber bundle straw based high-value agricultural products. [ABSTRACT FROM AUTHOR]

This study investigated the optimal autofrettage pressure and design method for improving the fatigue life of an ultra-high-pressure hydrogen valve attached to an ultra-high-pressure hydrogen storage vessel, which is responsible for the supply and control of hydrogen gas. The theoretical values calculated by the theoretical equation for determining the hoop residual stress formed by autofrettage pressure in a circular cylinder and the analytical values of the hoop residual stress obtained through finite element analysis of the autofrettage process in a porous circular cylinder using the commercial finite element analysis program ANSYS Workbench were well matched. Based on the analysis technique obtained for the porous circular cylinder, a quantitative target lifespan was examined for the ultra-high-pressure hydrogen valve with the shape of a porous circular cylinder, considering the maximum pulse pressure. As a result, the previously manufactured ultra-high-pressure hydrogen valve did not meet the quantitative target lifespan. To address this, the optimal values of displacement at specific locations where fatigue failure occurs and autofrettage pressure were designed using response surface methodology (RSM). Through this, fatigue life of 172710 cycles more than 150000 cycles (quantitative target lifespan) was obtained. [ABSTRACT FROM AUTHOR]

The performance and durability of wood-frame building envelopes is affected by long-term moisture transport and its impact. Despite considerable progress in deterministic and prescriptive methodologies aimed at estimating moisture deposition and the consequent risk of mold growth, a consensus in methodology applicable to the analysis of moisture risk in building enclosures is an unfinished agenda. This might partly be caused by uncertainties that exist due to variations in input parameters, model structure, and data scarcity. To address this issue, this study presents a probabilistic risk assessment of building envelope deterioration from moisture accumulation. The proposed methodology integrates the development of meta-models, a full-factorial response surface methodology, and Bayesian analysis. The effectiveness of the proposed approach is demonstrated through a parametric analysis of typical wall assemblies featuring diverse layers and boundary conditions. The findings highlight the influence of input variables and their relative significance on moisture accumulation in the selected climate zones. Additionally, a sensitivity analysis of model parameters and the application of Bayesian analysis in specific contexts are presented, facilitating comparative evaluation of moisture-related risk of building envelopes. [ABSTRACT FROM AUTHOR]

The present study focuses on the effects of vermicomposting on various soil properties, particularly emphasizing the dielectric characteristics of soil. Vermicomposting is known to significantly enhance soil fertility and improve its physical aspects such as aeration, porosity and water retention. In this analysis, a modified probe arrangement has been employed to determine how varying levels of vermicompost influence the soil's dielectric properties within the radio and microwave spectrum (10 MHz-14 GHz). A modified Dak-12 open-ended coaxial probe, paired with a vector network analyzer, was utilized for this purpose to overcome the drawbacks of standard arrangement. The results show that vermicompost strongly affects the soil's physical attributes (pH, bulk density, porosity) and also its chemical properties, along with its dielectric behavior. The study further explored the role of different factors such as the concentration of vermicompost, frequency and temperature on soil's dielectric response. To accurately and swiftly gauge these effects, Response Surface Methodology (RSM) has been employed to predict the dielectric properties (ε' and ε") of the soil. The high precision of these models, with R2 values of 0.9729 for ε' and 0.9487 for ε", underscores their effectiveness in evaluating the impact of vermicompost on various soil properties. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Dalian University of Technology / Dalian Ligong Daxue Xuebao is the property of Journal of Dalian University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Inorganic Chemicals Industry is the property of Editorial Office of Inorganic Chemicals Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Shenyang Pharmaceutical University is the property of Shenyang Pharmaceutical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Dalian Polytechnic University is the property of Journal of Dalian Polytechnic University Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)