Huge Structure Research Articles

Distributed control of a plate platform by NES-cells

Nonlinear energy sink (NES) has become a good passive vibration control technique with great potential. For a huge structure, it is unpractical to control the vibration by just one NES, let alone the structure has multi-modes. In this work, a technique who uses distributed nonlinear energy sink cells (NES-cells) to control the multi-modal resonance of the floating raft is proposed. The floating raft is simplified as a corner-point supported plate. Natural modes of it guide the distribution of NES-cells to make NESs locate on the position with strong vibration, which enhances the coupling ship between the plate platform and NES-cells. An example of installing NES-cells guiding by the first-two modes of the corner-point supported plate is presented in this paper. It is compared with the vibration reduction effect by a single NES. To make a fair comparison, total mass of NES-cells is the same with that of the single NES. The results show that NES-cells can deal with multi-modal vibration reduction better. The experimental results also fully illustrate this view. At the same time, the reaction of each NES-cell to the plate is effectively dispersed while comparing with the single NES, which decreases the stress at the attachment points and is more suitable for engineering applications. The number of NES-cells also has an effect on the vibration reduction efficiency. When the design parameters are fixed, there exists an optimal number to make the vibration reduction efficiency tend toward saturation. The multimodal vibration control of the plate platform is effectively solved by the proposed NES-cells technique. It also provides guidance for other practical engineering problems.

Leveraging an all-fixed transfer framework to predict the interpretable formation energy of MXenes with hybrid terminals.

MXenes have attracted substantial attention for their various applications in energy storage, sensors, and catalysts. Experimental exploration of MXenes with hybrid terminal surfaces offers a unique means of property tailoring that is crucial for expanding the performance space of MXenes, wherein the formation energy of an MXene with mixed surface terminals plays a key role in determining its relative stability and practical applications. However, the challenge of identifying energetically stable MXenes with multifunctional surfaces persists, primarily due to the absence of precise surface modification during experiments and the vast structural space for DFT calculations. Herein, we use an all-fixed transfer (AFT) framework combined with first-principles calculations to predict the formation energies of MXenes terminated by binary elements from groups VIA and VIIA. The trained model exhibits a high average R2 of 0.99, maintaining transferability and accuracy in predicting larger supercells from smaller-sized MXenes and datasets despite the structural imbalance between the training and prediction sets. The underlying interpretation of the high accuracy is revealed through the capture of main attributes and comparison of node features. Additionally, it is important to mention that the factors influencing the average formation energy include the types of element pairs, the ratio of terminal groups, and the distribution of terminations on two surfaces, with the first one being dominant. Finally, we successfully streamline the diverse structural cardinality of a large hybrid terminated MXene space of over 700 million, thereby facilitating the rapid screening of the top 5 stable MXene classes with binary terminal elements (FO, FCl, FBr, FS, and FSe). Besides, in the scenarios of lithium storage, the TL-predicted MXene can enhance its relative stability by increasing the fluorine ratio where the capacity can be optimized by different surface group combinations. All results indicate that the AFT framework has the advantages of screening functional MXenes with a huge structure space from smaller and imbalanced data sets.

Constructing 1D/2D NiCo‐LDH Nanowire/MXene Composites for Efficient And Stable Lithium Storage

AbstractBimetallic layered double hydroxide (LDH) delivers competitive performance in lithium‐ion battery (LIB) because of the unique layered structure. However, the electrochemical performance of LDH is hindered by the low conductivity and the huge structure change upon cycling. To face this challenge, the 1D/2D NiCo‐LDH nanowire/MXene composites (NiCo‐LDH/MXene) are dedicatedly constructed via a simple one‐step hydrothermal method. Owing to the robust conductive skeleton is enabled by MXene nanosheets and abundant electroactive sites provided by NiCo‐LDH nanowires, the NiCo‐LDH/MXene anode exhibits rapid ion diffusion, exceptional redox reaction, and superior structural stability. Consequently, it offers a high specific capacitance of 1081 mAh g−1 after 100 cycles at the current density of 100 mA g−1 and impressive rate performance, i.e., 439 mAh g−1 at the current density of 1000 mA g−1. These results will motivate the exploration of advanced electrode materials for application in energy storage devices.

Tunable double-layer dual-band metamaterial with negative mass density

Due to the huge structure and low efficiency of acoustic metamaterial (AM) with local resonance, a tunable dual-band AM with nested double layer hollow tube (NDLHT) is presented here, which is achieved by adjusting the inner or outer layer tube’s lengths or diameters to modulate the frequency band with the negative mass density. In addition, an accurate resonant frequency formula for OE-CE (Open End-Close End) NDLHT was derived based on the principle of standing wave resonance. The theoretical calculated resonant frequencies exhibit in good agreement with the simulated frequencies. Thus, the structural unit can then be actively constructed in the desired response frequency range using the geometric parameters that were obtained from this theoretical formula. This type of the nested AM with negative mass density has the advantages of high space utilization, active design, programmed modelling, customized production, 3D quantitative printing and is easily combined with other structure units with negative modulus to prepare AM with double negative in the desired frequency band.

Note on the finite vertex-based partitioning of supramolecular chain in Dialkyltin

ABSTRACT Complex networks are difficult to understand and deal with, yet building a graph of any complex and huge structure, whether chemical or computer-related, is quite straightforward. In the form of a graph theory view, it becomes simple to design networks. Each component's recognition is aided by the ease of its production in the form of graph theory. Finding a vertex (node or atom) in a structure is similarly difficult; in this instance, resolvability parameters come into play. This technique plays a significant role in managing or allowing access to each vertex in relation to some chosen vertices called a resolving set that shapes an entire cluster of vertices into a unique form and every single vertex is easy to recognise or locate, whether the small or large the structure. This article contributes the bounds on the parameter of partition dimension of chemical complexes in dialkyltin of supramolecular chain from N-Salicylidene-L-Valine. We supposed the complexes of chains from 2,3,4 and another chemical network, and we demonstrated that the number of vertices has a significant impact on the composition of resolving partition sets.

Numerical Simulation of Aerodynamic Characteristics of Electric Vehicles with Battery Packs Mounted on Chassis

Aerodynamic characteristics are of great significance to the fuel economy and handling the stability of electric vehicles. The battery pack of electric vehicles has a huge structure and is usually arranged in the chassis area of the vehicle, which inevitably occupies the space at the bottom of the vehicle and affects the aerodynamic characteristics of the vehicle. To study the effect of the power battery pack installed in the chassis on the aerodynamics characteristics of the electric vehicle, the Computational Fluid Dynamics (CFD) method is used to study the flow and pressure fields of the SAE (Society of Automotive Engineers) hierarchical car model with battery packs mounted on chassis. The influence of the structure parameters of the battery pack on the automobile’s aerodynamics are also analyzed in detail. Based on the simulation results, it can be seen that the battery pack installed on the chassis has a great impact on the flow and pressure field at the bottom and tail of the vehicle, causing the drag coefficient and lift coefficient to increase. The structural parameters of the battery pack have contradictory effects on the drag and lift coefficients. As the length of the battery pack increases, the drag coefficient decreases, and the lift coefficient increases. As the battery pack width and height increase, the drag coefficient increases, and the lift coefficient decreases. The research results provide a reference for the optimization of the aerodynamic characteristics of electric vehicles with battery packs mounted on chassis.

Process Parameters Analysis of Laser Phase Transformation Hardening on the Raceway Surface of Shield Main Bearing

The main bearing of the shield machine has a huge structure and severe service conditions, which are prone to wear and fatigue damage. To improve the anti-wear and anti-fatigue ability of the raceway surface of the shield main bearing, laser transformation hardening under different parameters of the shield main bearing raceway material 42CrMo steel was researched. The effects of laser power and scanning speed on the phase transformation of 42CrMo steel and the depth of the hardened layer were studied. The numerical model was verified using the theoretical and experimental results. Orthogonal tables of laser processing parameters are established. The results show that the depth of the hardened raceway layer increases with increased laser power and decreased laser scanning speed. According to the results of orthogonal primary and secondary analyses and fuzzy comprehensive evaluation, the depth of the hardened layer of the raceway can reach 1.08 mm, and the hardened layer is relatively uniform (laser power, 2250 W; scanning speed, 20 mm/s; spot length, 5 mm). The research in this paper provides a theoretical basis and technological innovation for the processing methods and engineering applications of high-reliability and long-life shield main bearings, which is of great engineering significance.

Numerical effect of seismic force on a medium arch dam

Abstract The dam is considered a huge structure that has multiple purposes in the life of a human. The most important role of a dam is the production of electricity, and the storage of a huge quantity of water. Therefore, it is very important to be vigilant in the studies made for it. Lebanon has indeed been designated as a seismicity country. However, the number of dams is increasing due to several natural consideration. Mseilha dam is an executed medium arch dam, which faced several problems during and after construction. The initial problem that faced a dam is the seismic force. This natural force is very dangerous for any structure, especially for a dam. It could increase the existing concrete stresses. These stresses will cause the development of cracks all along the dam. Once the concrete shows cracks, its resistance will decrease, and it will become more vulnerable to external effects. Several studies were made to fortify it and make it resistant to seismic force. To show the major effect of this force, two methods ‘pseudo-static’ and ‘response spectrum’ were applied to a medium arch dam. Therefore, to evaluate the performance of these two methods, the dam is modelled using finite element software. The obtained results show the importance of using the appropriate model in the design of such dams without taking the appropriate model.

MEA-Net: A Lightweight SAR Ship Detection Model for Imbalanced Datasets

The existing synthetic aperture radar (SAR) ship datasets have an imbalanced number of inshore and offshore ship targets, and the number of small, medium and large ship targets differs greatly. At the same time, the existing SAR ship detection models in the application have a huge structure and require high computing resources. To solve these problems, we propose a SAR ship detection model named mask efficient adaptive network (MEA-Net), which is lightweight and high-accuracy for imbalanced datasets. Specifically, we propose the following three innovative modules. Firstly, we propose a mask data balance augmentation (MDBA) method, which solves the imbalance of sample data between inshore and offshore ship targets by combining mathematical morphological processing and ship label data to greatly improve the ability of the model to detect inshore ship targets. Secondly, we propose an efficient attention mechanism (EAM), which effectively integrates channel features and spatial features through one-dimensional convolution and two-dimensional convolution, to improve the feature extraction ability of the model for SAR ship targets. Thirdly, we propose an adaptive receptive field block (ARFB), which can achieve more effective multi-scale detection by establishing the mapping relationship between the size of the convolution kernel and the channel of feature map, to improve the detection ability of the model for ship targets of different sizes. Finally, MEA-Net is deployed on the Jeston Nano edge computing device of the 2 GB version. We conducted experimental validation on the SSDD and HRSID datasets. Compared with the baseline, the AP of MEA-Net increased by 2.18% on the SSDD dataset and 3.64% on the HRSID dataset. The FLOPs and model parameters of MEA-Net were only 2.80 G and 0.96 M, respectively. In addition, the FPS reached 6.31 on the Jeston Nano, which has broad application prospects.

Optimization of Fluid Viscous Damper Diagonal & Combined Bracing Arrangement in G+9 RCC Structure

earthquake event is changeable by nature, which has the capacity make devastating operational damage to a structure and collapse in due course which leads the huge loss of life and huge structure property loss. Because of this, much realization has initiated by many researchers for the progress of structural rheostat techniques such as passive controlling and active controlling system which are associated in the systems of Tuned Mass Damper, Fluid Viscous Dampers, Base Isolation inhibiters etc. In this study an experimentation has been carried by in view of G+9 reinforced concrete structure with in the proliferation of quake analysis in SAP-2000. The G+9 RCC structure has been analyzed by means of the connection of fluid viscous dampers situated at numerous patterns in two various systems such as diagonal bracing and combined bracing system by a total of 30 types has been espoused by trial based in various stimulating patterns. The efficiency of that analyzed structural models had better be clearly pragmatic by means of the resultant structural performances, for instance lateral displacement, energy dissipation, storey drift and base response etc. The finest optimum arrangement of fluid viscous dampers had recommended to use for seismic response resistant structure for vibrating control system.

Study on fracture behaviour of basalt fibre reinforced asphalt concrete with plastic coupled cohesive model and enhanced virtual crack closure technique model

ABSTRACT In this study, the plastic coupled cohesive model and enhanced virtual crack closure technique (VCCT) are used to investigate the fracture behaviour of the basalt fibre reinforced asphalt concrete (BFRAC). In the plastic coupled cohesive model, the separation and traction response along the cohesive zone advance ahead of a crack tip is governed by an exponential cohesive law. The double-K fracture theory is integrated into the enhanced VCCT model. It is shown that the simulated load-cracking mouth opening displacement (P-CMOD) curves from both the plastic coupled cohesive model and the enhanced VCCT model compares favourably with the measured curves from the single-edge notched beam. The parameters used in the plastic coupled cohesive model cannot directly be obtained from the standard test, and the inverse analysis method is always necessary for identifying the fracture parameters. On the contrary, the fracture parameters in the enhanced VCCT method can be directly calculated from the P-CMOD curves based on the double-K fracture theory and the finite plastic fracture theory (Hutchinson, Rice, Rosengren singular crack tip fields, abbreviated as HRR field). Meanwhile, compared with the plastic coupled cohesive model, the enhanced VCCT model coupled with the Ramberg–Osgood elasto-plastic harden model is promising for investigating the physical mechanism underlying the nonlinear fracture of BFRAC. This paper proposed two concrete and valuable models in the finite element method for simulating the fracture behaviour of the huge structure with asphalt and asphalt concrete.

An asymptomatic huge primary retroperitoneal pseudocyst: a case report and review of the literature

BackgroundRetroperitoneal non-pancreatic or idiopathic pseudocysts are very rare lesions. This case report aimed to present our patient and to check all the available literature on this kind of rare disease.Case presentationOur patient was a 67-year-old Iranian man admitted with mild abdominal discomfort for three months. Ultrasonography and CT scan revealed a huge cystic structure within the retroperitoneal space. The lesion was excised through midline laparotomy and opening of the retro-peritoneum. The histopathology of the cyst wall revealed a benign cystic lesion with no epithelial lining. A histologic diagnosis of non-neoplastic retroperitoneal pseudocyst was made.ConclusionThe primary non-pancreatic retroperitoneal pseudocysts are rare lesions and have to be distinguished from other differential diagnoses of retroperitoneal lesions, and a surgeon should be aware of the possible occurrence of these lesions with unknown origin. Surgical excision is the only way to exclude malignancy and confirm the diagnosis.

Sensor Layout of Hoisting Machinery Vibration Monitoring Based on Harmony Genetic Search Algorithm

With the construction of automated docks, health monitoring technology as a parallel safety assurance technology for unmanned hoisting machinery has become a hot spot in the development of the industry. Hoisting machinery has a huge structure and numerous welded joints. The complexity and nonlinearity of the welded structure itself makes the structural failure parts random and difficult to arrange for monitoring sensors. In order to solve the problem of effectiveness and stability of the sensor arrangement method for monitoring the structure of hoisting machinery. Using the global and local search capabilities enhanced by the complementary search mechanism, a structural vibration monitoring sensor placement algorithm based on the harmony genetic algorithm is proposed. Firstly, the model is established for modal analysis to obtain the displacement matrix of each mode. Secondly, the optimal parameter combination is established through parameter comparison, and the random search mechanism is used to quickly search in the modal matrix to obtain the preliminary solution, and then the preliminary solution is genetically summed The mutation operation obtains the optimized solution, and the optimal solution is retained through repeated iterations to realize the decision of the vibration sensor layout of the crane structure monitoring. Combining the comparison test of harmony genetic algorithm, harmony search algorithm and genetic algorithm, the fitness of harmony genetic algorithm in <i>X</i>, <i>Y</i> and <i>Z</i> directions were 0.0045, 0.0084 and 0.0058, respectively, which were all optimal. And the average probability of deviating from the optimal path is 1.10%, 19.34%, and 54.43%, which are also optimal. Harmony genetic algorithm has the advantages of simplicity, fastness and strong global search ability, and can obtain better fitness value and better search stability.

Sharp bounds on partition dimension of hexagonal Möbius ladder

Complex networks are not easy to decode and understand to work on it, similarly, the Möbius structure is also considered as a complex structure or geometry. But making a graph of every complex and huge structure either chemical or computer-related networks becomes easy. After making easy of its construction, recognition of each vertex (node or atom) is also not an easy task, in this context resolvability parameters plays an important role in controlling or accessing each vertex with respect to some chosen vertices called as resolving set or sometimes dividing entire cluster of vertices into further subparts (subsets) and then accessing each vertex with respect to build in subsets called as resolving partition set. In these parameters, each vertex has its own unique identification and is easy to access despite the small or huge structures. In this article, we provide a resolving partition of hexagonal Möbius ladder graph and discuss bounds of partition dimension of hexagonal Möbius ladder network.

Venice Keeps Adriatic at Bay [Engineering flood defence

Hydraulics company Enerpac created caissons for three of the four barriers. It developed a damping and levelling control system, with four cylinders at each corner of the caisson and hydraulic accumulators, which absorb forces as the huge structure is placed onto metal sliding plates mounted on concrete mats positioned on the seabed. The control system cushions the momentum caused by lowering the caisson and an algorithm stops residual wave momentum from dislodging the caisson while it is being positioned. A watertight seal between caissons allows a service tunnel for maintenance once the project is complete. Construction work for the MOSE project began in 2003 and was scheduled to be completed in 2011, but delays - from environmental and conservationist challenges as well as bribery and corruption scandals, have resulted in a 10-year slippage and an increase in budget from euro1.6bn to euro5.5bn (around £4.8bn). Raising the gates takes 30 minutes and they remain closed for around four to five hours each time. The barriers have been tested every day since December last year, when they proved effective against high tides of 1.35m. The barriers are raised when there is a forecast of high water above 1.3m. In December 2020, incorrect forecasts of 1.2m-high tides meant that the gates were not raised and 1.37m-high waters flooded parts of the city. At the time, Venice&apos;s mayor, Luigi Brugnaro, said that the project is still being tested and that protocols would be developed to activate the defence system sooner. It was activated again shortly afterwards to protect the city from a 1.2m tide the following week. MOSE is scheduled to be fully operational by the end of this year to protect historic buildings and Venetians&apos; businesses from the Adriatic Sea.

Induction drive system with DSTATCOM based asymmetric twin converter

High power demands are usually met by advanced power electronics converters in several large utility and electric drives applications. Applications from high power drives commonly uses solution based multi pulse and multilevel converters. A common DC link with atleast one voltage source converter (VSC) working with almost fundamental switching frequency are used in converters of multipulse type, and each output module is connected with the multipulse transformer in series. When compared to that of solution with single-VSC, Several VSCs generating different triggering pulses are adjused in order to achieve current injected with low specified total harmonic distortion (THD) with losses of abridged switching. Huge structure in complexity and expensive cost expenditure of the multipulse transformer is the major limitation of this scheme. DC link split capacitors in addition are eliminated by modifying the topology of the circuit. Thus, the independent voltages of the DC capacitor are controlled and decreased in number and the flow of third harmonic current component in the transformer is eliminated. The scheme of the designed controller is depending on the derived mathematical system model. Simulaion observation is used to check the scheme performance and efficiency in a detailed way with drive control technique.

Assessment of geothermal power potential in Buyuk Menderes Basin, Turkey

Turkey’s installed geothermal capacity for power generation as of December 2019 is 1500 MWe. Most of this installed capacity is generated by the power plants located in the Buyuk Menderes graben. Geologically Buyuk Menderes graben is a huge structure having several discovered geothermal resources and can be considered as a geothermal basin.The aim of this study is to estimate the geothermal power potential of Buyuk Menderes graben. To achieve this object, a stochastic methodology, which is used to evaluate hydrocarbon-bearing basins, is adapted from the oil and natural gas industry. This methodology provides a way to quantify the geothermal potential in a range of possible values by evaluating the individual fields in the basin using stored heat technique. A total of 34 (21 proven and 13 probable occurrences) geothermal fields having medium to high temperature (T ≥ 100 °C) values are evaluated using the Monte Carlo Simulation technique. In these simulations, available geological, geochemical, geophysical data are used along with the data obtained from the drilled wells in the region.The power potential (MWe) values for 21 proven fields in terms of P10, P50 and P90 values are determined to be 888, 1077 and 1311 MWe, respectively. Considering the 13 probable occurrences along with the proven fields, the lower and upper limits of the total power potential (P10 and P90) are 1156 and 1580 MWe, respectively. Moreover, the power potentials are also evaluated under the presence of uncertainty. By assigning 5/13, 6/13, and 7/13 probability values for the 13 probable occurrences, overall geothermal power potential P10 values are estimated as 1041, 1075, and 1101 MWe, respectively.

On Wireless Sensor Network Lifetime Prolong and Efficient Routing By Energy Path Balancing

Remote sensor frameworks (WSN) associations explicit transducers that give distinguishing organizations to Internet of Things (IoT) gadgets with controlled power and limit sources. Since choice or stimulating of batteries in sensor centers is about unreasonable, quality use gets one of the huge structure issues in WSN. Gathering figuring expect a basic activity in power safeguarding for the imperativeness controlled framework. Picking a gathering head can decisively modify the weight inside the framework there by reducing power confirmation and improving lifetime. In this test, we favoring imperativeness careful packing for remote sensor organizes the use of EARR (Energy Aware Routing and Relay Relocation) set of concludes that is applied on the WSN. The show thinks about both power execution and transmission partition, and move center points are used to reduce the lopsided power confirmation of the bundle heads. The proposed show impacts in higher allotted sensors and a suitably balanced bundling contraption improving the system's lifetime. The EARR strategy passes on two shows, which consolidate MCP, based completely EAR and Relay Relocation essentially based EAR. In area I, Transmission go adjusting by the presenting the Maximum Capacity Path based multi ricochet coordinating by using constraining Energy Aware Routing. For the EAR use, need to learn the center points Initial Energy, Residual Energy and Optimum power way. These parameters will ensure the green way and CH levels of leadership to improve the system as a rule execution despite lifetime. The figuring and the reenactment and examine the present R-LEACH and proposed EAR-MCP strategy to the extent throughput, extra quality and inertness with the guide of using NS2 test framework.

Development of a New-type Nail-fold Microcirculation Imaging Device

At present, there are many problems in the nail-fold microcirculation detection devices, such as huge structure, inconvenience to carry. In addition, due to the patient's body shaking, the video is difficult to keep stable in collecting with the device, which brings great difficulties to the doctor's observation. We develop a small image acquisition device for nail-fold microcirculation based on the principle of SDF imaging principle and liquid lenses technology. An annular lighting device is fixed in front of the optical system, and the overall design of the system is based on the characteristics of human fingers. The device is small, easy to carry and conform to the fingertips. It can focus quickly through a controller. It can also achieve high quality images of the nail-fold microcirculation. This study can promote the usage of nail-fold microcirculation device at the bedside. It's an efficient tool for medical workers to observe the microcirculation of patients.

Synthesis and characterization of UV-cured epoxy acrylate resin with cyclic methacrylate as diluents

PurposeThis paper aims to investigate the effects on material performance in the epoxy acrylate resin system owing to the existence of the different ring of the cyclic methacrylate. In this paper, cyclic methacrylate as diluents was added into epoxy acrylate (EA) resin by ultraviolet (UV)-cured polymerization to investigate the effects on material performance owing to the existence of the different rings.Design/methodology/approachEA and 1-adamantyl methacrylate were synthesized by traditional methods according to previous papers, respectively. After adding different cyclic methacrylate as diluents to the EA oligomers, the system was exposed to the UV-light for polymerization.FindingsThe hydrophobic properties of the cured materials were increased slightly because of the alkyl groups from the methacrylate. The thermal stabilities and mechanical properties of the resins were enhanced by the cyclic diluents with the hard segments. Meanwhile, the crosslink density of the polymer decreased with the bulky group like adamantly owing to its huge structure.Research limitations/implicationsThe cyclic methacrylates were introduced into EA oligomers for decreasing the viscosity and increasing the materials performances, which could be recognized as new diluents applied in UV-cued polymerization.Originality/valueThe results of this study will be conducive to fabricate EA resins possessed with high thermal stabilities and mechanical properties by convenient UV-cured polymerization.