Cubical Shape Research Articles

Significant effects of mixed cations on the morphology and photochemical activities of alkali-metal-antimony (Na,K)Sb3O7.

Oxide semiconductors with mixed-valence states generally exhibit excellent optoelectronic and photochemical properties due to facile charge transfer in redox reactions. In this work, we investigate the effects of mixed alkali on the optical absorption, luminescence spectra and photocatalytic abilities of (Na1-xKx)Sb3O7 nanoparticles. All the samples are fabricated using a simple one-step hydrothermal method. The structural studies show that the largest substitution of K+ ions in (Na1-xKx)Sb3O7 is at x = 0.3. In hydrothermal synthesis, the mixed arrangement of K+ and Na+ in (Na1-xKx)Sb3O7 has an influence on the crystal shape of particles. NaSb3O7 develops into a regular cube shape. With the increase of K+ ions in (Na1-xKx)Sb3O7, the edges and corners of the cube are further ground off, resulting in irregularly spherical particles. This mixed-alkali antimonite belongs to a p-type indirect allowed transition semiconductor, and the optical band gap is 2.71 eV (x = 0.3). The intrinsic luminescence of NaSb3O7 is detected at 540 nm, which is nearly quenched in Na0.7K0.3Sb3O7. It is demonstrated that the substitution of K+ in NaSb3O7 significantly increases the photodegradation of RhB solutions. There are two types of Sb cations, i.e., Sb5+ and Sb3+ mixed in the structure. The improved photocatalysis is attributed to the charge mediators between Sb5+/Sb3+ couples. The experiment shows that co-doping cations in antimonite oxides may be one of the strategies to improve photochemical properties.

UAV Formation Control under Fixed and Variable Adjacency Based Directed Network Topologies

The UAV formation control is one of the key aspects in several applications like surveillance, moving target tracking, load-transportation, and delivery systems etc. These situations demand the multiple UAVs to manoeuvre in a desired formation. To address this problem, a distributed formation control scheme is proposed incorporating the details about the state of the neighbouring UAVs. The communication network topology among the UAVs is considered to be directed with the constant and the weighted adjacency matrices. The nonholonomic constraints are considered while deriving the desired Euler angles. Satisfying the conditions of Lyapunov provides necessary proof of stability along the positional and the attitude subsystems. Simulation results demonstrate that the desired tetrahedron, octahedron, and cube shapes are attained and maintained by the UAVs successfully. Also, the designed formation paradigm works proficiently for both the constant and the weighted adjacency matrices based directed network topologies. The performance validation is done through extensive comparative analysis for varying network connections.

Controlling Lattice Misfit and Creep Rate Through the γ' Cube Shapes in the Al10Co25Cr8Fe15Ni36Ti6 Compositionally Complex Alloy with Hf and W Additions

Trace elements play an important role in the fine-tuning of complex material properties. This study focuses on the correlation of microstructure, lattice misfit and creep properties. The compositionally complex alloy Al10Co25Cr8Fe15Ni36Ti6 (in at. %) was tuned with high melting trace elements Hf and W. The microstructure consists of a γ matrix, γ' precipitates and the Heusler phase and it is accompanied by good mechanical properties for high temperature applications. The addition of 0.5 at.% Hf to the Al10Co25Cr8Fe15Ni36Ti6 alloy resulted in more sharp-edged cubic γ′ precipitates and an increase in the Heusler phase amount. The addition of 1 at.% W led to more rounded γ′ precipitates and the dissolution of the Heusler phase. The shapes of the γ' precipitates of the alloys Al9.25Co25Cr8Fe15Ni36Ti6Hf0.25W0.5 and Al9.25Co25Cr8Fe15Ni36Ti6Hf0.5W0.25, that are the alloys of interest in this paper, create a transition from the well-rounded precipitates in the alloy with 1% W containing alloy to the sharp angular particles in the alloy with 0.5% Hf. While the lattice misfit has a direct correlation to the γ' precipitates shape, the creep rate is also related to the amount of the Heusler phase. The lattice misfit increases with decreasing corner radius of the γ' precipitates. So does the creep rate, but it also increases with the amount of Heusler phase. The microstructures were investigated by SEM and TEM, the lattice misfit was calculated from the lattice parameters obtained by synchrotron radiation measurements.

Microstructure Reconstruction and Multiphysics Dynamic Distribution Simulation of the Catalyst Layer in PEMFC.

Due to the complexity of both material composition and the structure of the catalyst layer (CL) used in the proton-exchange membrane fuel cell (PEMFC), conjugated heat and mass transfer as well as electrochemical processes simultaneously occur through the CL. In this study, a microstructure model of CL was first reconstructed using images acquired by Nano-computed tomography (Nano-CT) of a real sample of CL. Then, the multiphysics dynamic distribution (MPDD) simulation, which is inherently a multiscale approach made of a combination of pore-scale and homogeneous models, was conducted on the reconstructed microstructure model to compute the corresponded heat and mass transport, electrochemical reactions, and water phase-change processes. Considering a computational domain with the size of 4 um and cube shape, this model consisting of mass and heat transport as well as electrochemical reactions reached a stable solution within 3 s as the convergence time. In the presence of sufficient oxygen, proton conduction was identified as the dominant factor determining the strength of the electrochemical reaction. Additionally, it was concluded that current density, temperature, and the distribution of water all exhibit similar distribution trends, which decrease from the interface between CL and the proton-exchange membrane to the interface between CL and the gas-diffusion layer. The present study not only provides an in-depth understanding of the mass and heat transport and electrochemical reaction in the CL microstructure, but it also guides the optimal design and fabrication of CL components and structures, such as improving the local structure to reduce the number of dead pores and large agglomerates, etc.

Convex Cube-Shaped Pt34 Fe5 Ni20 Cu31 Mo9 Ru High Entropy Alloy Catalysts toward High-Performance Multifunctional Electrocatalysis.

High entropy alloy (HEA) catalysts exhibit excellent multifunctional catalytic performance due to the synergistic effect of multi-metal components. However, shape-controlled synthesis of such kinds of HEA catalysts, especially those with high index facets, still faces great challenges, limiting further enhancement of their catalytic performance. Herein, one-pot synthesis of convex cube-shaped Pt34 Fe5 Ni20 Cu31 Mo9 Ru HEA catalysts which possess rich (310) facets and a diagonal crystalline size of 38.5nm is reported. Transmission electron microscopy measurements indicate cube-shaped nanocrystals are obtained first and further selective growth of pyramid on each facet of the cube-shaped nanocrystal results in a convex cube shape. Pt34 Fe5 Ni20 Cu31 Mo9 Ru HEA catalysts show excellent electrocatalytic performance toward the oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), and oxygen evolution reaction (OER), which exhibit a half-wave potential of 0.87V for ORR in 0.1m HClO4 , and overpotential of 20 and 259mV for HER and OER at a current density of 10mA cm-2 in an alkaline medium. A control experiment and density functional theory calculation indicate that the Ru element plays a decisive role in both the formation of the convex cube shape and also the high catalytic performance.

SLMGAN: Single-layer metasurface design with symmetrical free-form patterns using generative adversarial networks

The metasurfaces offering the required spectral responses have ushered in a revolution of manipulating the light in a prescribed manner. A single-layer metasurface design is more appealing than a multi-layer one due to the fabrication complexities. To date, various research groups have explored on architected metasurfaces with general shapes of cubes, crosses, or octothorpes, while a few works utilized evolutionary algorithms to search for metasurfaces with free-form patterns, which relied on the quality of the initial guess. In this paper, a solution is presented to replace the intuition-based approach with generative adversarial networks. The constructed generative networks mathematically formulate the virtual mappings between the pairs of optical spectra and symmetrical patterns with user-defined geometric structures. When fed a time sequence of spectra, the designed networks assimilate the physical property and generate on-demand patterns to match the desired responses. The output patterns are proved to yield matching optical responses with an average accuracy of 0.9. Generative Adversarial Networks are firstly applied to single-layer metasurface designs with symmetrical free-form patterns for desired optical spectra in an inverse-design system.

Unveiling facet effects in metallic nanoparticles to design an efficient plasmonic nanostructure

We investigated the role of nanoparticle surface morphology (facets) in estimating the plasmonic properties of nanoparticle-on-a-mirror design or NPOM in the presence of a thicker (20 nm) dielectric layer. Nanoparticle surface morphology differences ranging from smoother surface to multi-facets in the form of a sphere (NSOM), cube (NCOM), and singe bottom faceted sphere (SBF-NSOM) shapes have been employed. Three significant optical properties were observed. Better longer wavelength near-field and far-field resonance spectral positions from NCOM are achieved. Near-field enhancement extracted from SBF-NSOM outperformed NCOM by more than ∼ two times. Plasmonic gap mode enhancement is absent for NSOM in the presence of a larger dielectric layer. The availability of plasmonic gap modes in NCOM and SBF-NSOM, even at a 20 nm thick dielectric layer, is highly beneficial for various plasmonic applications. These differences in optical properties are understood by the role of NP facets in influencing the plasmonic cavity region.

Synthesis of mica supported tungsten oxide nanoparticles and their photocatalytic, biological and antioxidant activity

ABSTRACT Mica-supported tungsten oxide (M/WO3) and neat WO3 nanoparticles (NPs) were synthesised through acid precipitation method and then used as photocatalysts for degradation of Methyl Violet (MV) dye in aqueous media. The scanning electron microscopy (SEM) shows that the majority of WO3 NPs have cubical shape. The SEM micrographs also illustrated that the particles are mostly present in dispersed form, while some are in agglomerated form. The transmission electron microscopy (TEM) presented that the size of the nanoparticles were below 100 nm. The formation of NPs were also confirmed by energy dispersive X-ray (EDX), X-ray diffraction (XRD) and Fourier transform infra-red (FT-IR). The photodegradation study presented that WO3 and M/WO3 NPs degraded about 87% and 97% of MV dye within 75 min irradiation time under UV light. The recovered and re-recovered M/WO3 and WO3 NPs also significantly degraded MV dye. Both WO3 and M/WO3 NPs showed significant bio-activities against two pathogenic bacteria (Citrobacter and Providencia). Further, both types of NPs showed effective antioxidant activity.

Synthesis and effect on the surface morphology & magnetic properties of ferrimagnetic nanoparticles by different wet chemical synthesis methods

Ferrimagnetic nanoparticles (FMNPs) were synthesized using different wet chemical synthesis methods. In particular, the chemical co-precipitation method (CCPM), sol-gel method (SGM), hydrothermal method (HM), and sonochemical method (SM) were used for the preparation of FMNPs. The work aims to explore the influence of different synthesis methods on the structural and magnetic properties of synthesized FMNPs. The physical morphology, chemical composition, and magnetic properties of the FMNPs were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Zeta potential, particle size distribution, and vibrating sample magnetometer (VSM). The experimentations observed that the FMNPs obtained through CCPM exhibited a stable cubical shape of 11.80 nm. The chemical co-precipitation method was also more cost-effective and time-efficient than the other wet-chemical methods. On the other hand, FMNP prepared by the hydrothermal method showed higher magnetic strengths of 89.34 emu/g with a suitable particle size distribution of −24.43 mV. The highest synthesis time was required for the sol-gel method, followed by the hydrothermal, sonochemical, and co-precipitation methods. • In this work, the synthesis of ferrimagnetic nanoparticles is carried out. • Four different wet chemical methods are used for the synthesis of nanoparticles. • Chemical co-precipitation method requires the least synthesis time (≈12 h). • The sol-gel synthesis requires the largest synthesis time (around 85 h). • M s = 89.34 emu/g with 20.52 nm size was observed for the hydrothermal method.

Effect on Perceived Weight of Object Shapes.

The perceived weight of an object is an important research topic in terms of sensation and perception, and it is known that it has size-weight, color-weight, and material-weight illusions due to the influence of size, color, and material, as well as the weight of the object. Although the physical size of an object is measured by volume, the size of an object that we subjectively feel depends on the shape of the object, even if it has the same volume. Therefore, the shape of the object may determine the perceived size of the object, thereby changing its perceived weight accordingly. These cognitive factors play an important role in the period of rehabilitation therapy after an exacerbation or attack of neurological diseases, such as stroke or Parkinson’s disease, regarding the motor functions of the patient. Moreover, the study of these sensation and perception factors is important for the period of the early development of children, for example, for tracking and correcting fine motor skills. Existing related studies analyzed the perceived weight according to three shapes (tetrahedron, cube, and sphere), but only some shapes showed a difference in the perceived weight. This study attempted to demonstrate the difference in perceived weight according to the shape that has yet to be clearly identified. To this end, this study investigated objects with the same physical size (volume) as in previous studies, but in the shapes of tetrahedron, cube, and sphere. In addition, the volumes of these objects were set to 64,000 cm3, 125,000 cm3, and 216,000 cm3, and their weights were set to be 100 g, 150 g, and 200 g, in proportion to the size of the small, medium, and large volumes, respectively. Thirty-eight college students (21 males, 17 females) participated and the perceived weight of a given object compared to a reference object was evaluated according to the modulus method used for sensory size measurement. The analysis of the experimental data found that both weight (volume) and shape had significant effects on the perceived weight. The results support that the shape of objects also led to the size-weight illusion phenomenon. At the same weight (volume), the perceived weight of an object according to shape decreased significantly in the order of sphere, cube, and tetrahedron. At the same volume level, subjective size according to shape is small in the order of tetrahedron, cube, and sphere. The results of weight perception according to shape in this study showed that the subjective size of an object according to shape had an effect on perceived weight.

The effectively optical emission modulation in perovskite MAPbBr3 crystal by hot-electron transfer from metals

Optical emission modulation is an effective way to improve material properties and to enlarge their applications. However, a significant problem still facing challenge is low efficiency in optical emission enhancement. To contribute this, this work aims to achieve efficient hot electron transfer resulting emission enhancement used the help of plasmon resonance near-field enhancement and combined with excitation energy. Thus, a simply method of metal-perovskite heterojunctions preparation was conducted. The optical crystal of Au nanoparticles/nanocages attached on perovskite MAPbBr3 (NP-C) is presented. The hot electron transfer signal in ion’s vibration is characterized by XRD and Raman spectrum firstly. The cube shape and size distribution mostly in 550–850 nm morphology is revealed by SEM. The carrier concentration is improved about 37.5%, the mobility and resistivity are lowered around 53.2% and 26.7% after soaking in solution, respectively. What’s importantly, the effective modulation of intensity and peak position are achieved at room temperature, which is caused by the behavior of hot-electrons transfer suggested by FDTD simulation. The evidence for hot-electron transfer at the interface in Au–MAPbBr3 in 150 fs are proved by transient absorption spectrum. Finally, the mechanism of optical modulation, band gap structure and hot electrons transfer are depicted. This paper can provide experimental reference for emission enhancement and the development of devices based on hot electrons transfer.

Exploring the Impact of Bioformulated Copper Oxide Nanoparticles on Cytomorphology of Alternaria brassicicola.

Black leaf spot of Brassica species is caused by a foliar pathogen Alternaria brassicicola (A. brassicicola), the noxious killer of mustard, cabbage, and cauliflower crops. The current investigation involved the synthesis of copper oxide nanoparticles (CuO NPs) from potential strain of Trichoderma harzianum (T. harzianum). Characterization of CuO NPs was performed by UV-vis, FTIR, XRD, SEM-EDX, and HR-TEM studies. UV-visible spectra showed an absorption peak at 275nm. FTIR study revealed the presence of N-H bonds which could be due to the presence of enzymes and secondary metabolites released in the filtrate of T. harzianum. SEM and HR-TEM revealed the cube shape CuO NPs formed and average particle size was in the range of 31-45nm. Poisoned food technique was used to check the antifungal efficacy of CuO NPs against A. brassicicola at various concentrations (0.025, 0.050, 0.1, and 0.15mg/mL). In vitro assays carried on potato dextrose agar showed maximum antifungal activity at 0.15mg/mL. The control sample have cylindrical and oblong shape conidia, while transverse septation was 2-4 in untreated population. The lower concentrations of CuO NPs (0.025 and 0.050mg/mL) caused malformed spherical shape conidia with excessive septation, while its higher concentrations (0.1 and 0.15mg/mL) leads to viability loss in fungal culture. Results indicated that a higher concentration of CuO NPs serve as an effective biocidal concentration for the control of phytopathogens.

Chemical fabrication, structural characterization and photocatalytic water splitting application of Sr-doped SnO2 nanoparticles

Semiconductor photocatalysis has gained considerable attention in recent years due to their enabling nature to convert solar energy into fuels of renewable hydrocarbon. However, many of them suffer from some drawbacks like the inability to visible light irradiation and wide band gaps. Herein, we have synthesized monophasic strontium (Sr) doped SnO2 nanoparticles by a cost-effective and environmental friendly hydrothermal method. As-synthesized nanoparticles showed rutile crystalline structure with irregular and rough cubical shape and no other elemental impurities. Sr-doped SnO2 nanoparticles show a constant decrease in bandgap with increasing dopant concentration, which is estimated for excellent photocatalytic activity. The photocatalytic water splitting of as-prepared Sr-doped SnO2 nanoparticles for H2 generation shows a large influence of the increasing dopant concentration related to the narrowing bandgap on H2 generation rate. Hence, the tunable bandgap with adjusted dopant concentration indicates that band gap tuning through doping for produced nanostructures may open up a new opportunities for photocatalytic and other optoelectronic applications.

Tuning the structural, optical and magnetic properties of NiCuZn (Ni0.4Cu0.3Zn0.3Fe2O4) spinel ferrites by Nb2O5 additive

Ni0.4Cu0.3Zn0.3Fe2O4 ferrites with various compositions (0–5 wt. %) of Nb2O5 additive were synthesized by the sol-gel method with an aim to investigate their physical properties. The analysis of Rietveld refined X-ray diffractograms confirms formation of ferrites with a single-phase spinel structure having space group Fd3m. The result indicates that there is an enhancement in the lattice parameter values with increasing Nb2O5 content. The nanoparticles in the shapes of spheres and cubes with few agglomerations were evident from field emission scanning electron microscope images of ferrites. The elemental analysis from energy dispersive X-ray spectrum confirms the stoichiometric occurrence of constituent elements within the prepared samples. The Raman spectra confirm the cubic spinel structure of the prepared ferrite samples. The Fourier transform infra-red spectra confirm the superseding of Nb5+ ions in the unit cell of NiCuZn ferrite. Oxidation states of the elements within the ferrite were confirmed by means of X-ray photoelectron spectroscopy. The UV–Visible diffused reflectance spectroscopy results show that the band gap energy values were reduced with the increasing wt.% of Nb2O5 additive in the ferrite. The Nb2O5 additive reduces the saturation magnetization and coercivity of all the ferrite samples. The study reveals that the controlled amount of Nb2O5 additive in NiCuZn ferrite can tune the soft magnetic behavior and optical parameters of the ferrite at room temperature.

Seismic Performance of I-shaped Beam-column Joint with Cubical and Triangular Slit Dampers Based on Finite Element Analysis

From the layout of a metallic structure`s beam-column connection w, while the seismic design is inside the dissipative method, precise contributors and zones ought to admit the growth of plastic deformation, and many metallic second resisting frames fail on the beam-column joints. This examines designed a unique structural machine with diverse slit dampers to triumph over this challenge, which can be easier to deliver overall seismic performance in the structural device that has been proposed. Plastic deformation is confined to the slit dampers at the end flange, which is the machine's key characteristic. The recommended connection's seismic overall performance changed into confirmed the use of the Abaqus software program utility to software systems with diverse slit damper forms. The proposed hyperlink exhibited first-rate hysteretic conduct in accordance to check results. Furthermore, on this machine, strength dissipation and plastic deformation focus on the diverse shapes of slit dampers, while the inelastic behaviour of the beams and columns is prevented via a suitable ability layout. The conduct of triangular and cubical shapes of slit dampers withinside the connection among a metallic beam and a container column is defined in this paper.

Box-Behnken design optimized silibinin loaded glycerylmonooleate nanoliquid crystal for brain targeting

Silibinin (SIL) is a neuroprotective and amyloid aggregate inhibitor that showed therapeutic applications in preclinical studies of Alzheimer’s disease (AD). Due to poor aqueous solubility free SIL is unable to reach the brain after oral administration. Therefore SIL was encapsulated in nano-liquid crystals (NLCs) to increase payload in brain using glyceryl monooleate (GMO). The NLCs were prepared through the emulsification and probe sonication method. The optimization of SIL-NLCs was done using Box-Behnken design (BBD). BBD investigated the effect of independent variable such as GMO weight, pluronics-127 (PF-127) concentration, and sonication time on critical quality attributes such as particle size and percentage drug loading (%DL) for enhancement of drug availability at targeted site. The particle size of SIL-NLCs optimized by BBD was found to be 113.2 ± 3.3 nm particle size and 8.02 ± 0.4% DL. The FTIR and DSC characterization of SIL-NLCs showed SIL is dispersed in the GMO matrix in the amorphous form. TEM analysis confirmed the cubical and crystal-like shape of the NLCs having particle size less than 150 nm. After single oral gavage of a 30 mg/kg dosage of SIL in Wistar rats, the pharmacokinetic investigations revealed that the amount of SIL available in plasma of animals administered with NLCs showed AUC0-∞ = 19.61 µg mL−1 h compared to free SIL group having AUC0-∞ = 6.72 µg mL−1 h (P > 0.005). Brain uptake studies showed SIL-NLCs treated groups have 2.25 µg/g availability of SIL compared to 10.02 µg/g for the free SIL group. The outcomes of this investigation are promising in terms of potential use of SIL-NLCs in further studies as well as using SIL for the treatment of AD.

Synthesis, Characterization and Remedial Action of Biogenic Silver Nanoparticles and Chitosan-Silver Nanoparticles against Bacterial Pathogens

Custard apple is a dry land fruit. Its leaves exhibit different pharmacological activities. In the present study, both silver (Ag) nanoparticles and chitosan-coated Ag (Chi-Ag) nanoparticles were fabricated using the aqueous leaf extract of the custard apple plant. During preliminary phytochemical analysis, various types of phytocompounds were found in the aqueous leaf extract of the same plant. Next, both nanoparticles were physiochemically characterized. FTIR analysis exhibited the fingerprint vibrational peaks of active bioactive compounds in plant extract, Ag nanoparticles, and Chi-Ag nanoparticles. UV/Visible spectral analysis revealed the highest absorbance peak at 419 nm, indicating the presence of Ag nanoparticles. XRD analysis presented the face-centered cubic (FCC) structure of both prepared nanomaterials. Further, the average crystalline size of both Ag nanoparticles and Chi-Ag nanoparticles was calculated to be 23 and 74 nm, respectively. FESEM analysis showed the spherical and cubical shapes of Ag nanoparticles and Chi-Ag nanoparticles, respectively. EDS analysis indicated a peak around 3.29 keV, conforming to the binding energies of Ag ions. The biogenic nanomaterial also showed strong antibacterial activity against all tested bacterial pathogens.

Molecular dynamics study on the effect of external electric field on thermal properties of ammonia/copper nano-refrigerant in a nanochannel equipped with different types of cavities

Optimizing and increasing the efficiency of heat transfer systems was one of the main challenges for engineers and designers in recent years. Therefore, the use of nanoparticles in base fluids is known as a passive method to improve heat transfer and shrink heating and cooling systems. In this research, the heat transfer of copper nanoparticles with ammonia refrigerant in a nanochannel was investigated by molecular dynamics simulation. The results show that, with increasing the electric field frequency from 0.1 1/ps to 0.5 1/ps, the phase change time increases from 2 ns to 3 ns and the thermal conductivity decreases from 0.76 W/m.K to 0.72 W/m.K. Also, the effect of the different cavities (hermetic, spherical, and cube shape) in the nanochannel on the atomic and thermal behavior of the simulated atomic samples is investigated. The results show that the maximum thermal conductivity of the sample with a cubic cavity is 0.80 W/m.K. The particle phase change value and the phase change time of samples with hermitic, spherical, and cube atomic cavities are obtained 65, 66, and 68%, and 2.88, 2.87, and 2.85 ns, respectively.

SHAPE OPTIMIZATION OF ROCKFILL DAM WITH RUBIK CUBE REPRODUCTION BASED MULTI-OBJECTIVE PARTICLE SWARM ALGORITHM

A rockfill dam's quality and its economic aspects are inextricably interwoven with each other. Approaching the optimal design of a rockfill dam paves the path to achieve the best quality with the fewest expenses. Choosing the Sardasht rockfill dam as a case study, two semi-empirical models are presented for seepage and safety factor. These two models, together with construction costs, were employed as three objective functions for the Sardasht rockfill dam's shape optimization. Optimization was handled using a robust multi-objective particle swarm optimization algorithm (RCR-MOPSO). A new reproducing method inspired by a Rubik's cube shape (RCR) and NSGA-III are building blocks of RCR-MOPSO. Three benchmark problems and two real-world problems were solved using RCR-MOPSO and compared with NSGA-III and MOPSO to ensure the performance of RCR-MOPSO. The solution quality and performance of RCR-MOPSO are significantly better than the original MOPSO and close to NSGA-III. Nevertheless, RCR-MOPSO recorded a 38% shorter runtime than NSGA-III. RCR-MOPSO presented a set of non-dominated solutions as final results for the Sardasht rockfill dam shape optimization. Due to the defined constraints, all solutions dominate the original design. Regarding the final results, compared with Sardasht dam's original design, the construction price was reduced by 31.12% on average, while seepage and safety factor improved by 15.84% and 27.78% on average, respectively.

Comparative study on heat extraction performance of geothermal reservoirs with presupposed shapes and permeability heterogeneity in the stimulated reservoir volume

The stimulated reservoir volume (SRV) is critical to the heat extraction from an enhanced geothermal system (EGS). Being different from previous simple cube-shape SRV, this study proposes a new shape SRV with heterogeneous permeability to evaluate the heat extraction performance of an EGS. First, the new shape SRV is generated based on the location and density of microseismic events during multi-stage hydraulic fracturing. Other two SRVs with simple cube or complex shape but same volume are generated for comparison. Second, a fractal permeability is developed for the heterogeneous SRV domain. Third, a thermal-hydraulic (TH) coupling model is implemented for the heat transfer and water flow in these three SRVs. Finally, the EGS performances of these three SRVs with a stimulated volume of 0.405 km 3 are comparatively evaluated through numerical simulations. Numerical simulations reveal that the EGS with cube-shape SRV overestimates both output temperature and energy extraction. The heterogeneous permeability in the SRV domain leads to a dramatic increase of reservoir impedance. This reduces energy extraction efficiency and breakthrough time, thus shortening the lifetime of the EGS system. • A new shape SRV with heterogeneous permeability in HDR reservoir is proposed. • An evaluation system for EGS is established based on a TH coupling model. • EGS performance of the three presupposed SRVs is comparatively analyzed. • The feasibility of a megawatt EGS power plant in Gonghe Basin is discussed.