Design Aid Research Articles

Numerical investigation on explosion hazards of lithium-ion battery vented gases and deflagration venting design in containerized energy storage system

Large-scale Energy Storage Systems (ESS) based on lithium-ion batteries (LIBs) are expanding rapidly across various regions worldwide. The accumulation of vented gases during LIBs thermal runaway in the confined space of ESS container can potentially lead to gas explosions, ignited by various electrical faults. However, a systematic simulation and assessment of the battery vented gases explosion under deflagration venting design still lack. In this work, a three-dimensional combustion model was developed within the frame of open source computational fluid dynamics code OpenFOAM based on a full-scale container, and the LIBs vented gases in realistic proportion were selected as the combustion gas. Coupled boundary conditions were introduced to enable the response of explosion vent doors and top deflagration vent panels on pressure. The internal and external overpressure, flame temperature, and wind velocity fields were employed to assess the gas explosion hazards to ESS container structure and surroundings. The results demonstrate that altering the vent door pressure, without the top vent panel, still leads to serious explosion accidents. There will be unacceptable overpressure for the container structure, as well as serious visible flames and high-speed airflow invading the external environment. Lower vented gas concentrations can reduce explosion hazards, and introducing the vent panel design aids to promote such reduction. The overpressure within the container is significantly decreased by guiding the top external secondary combustion through the vent panel, and the influence range for the environments is also significantly reduced on X-axis. The ignition location can affect the propagation of gas combustion within the container, and the proposed complete vent panel design minimizes the impact on the container structure and surroundings. The findings of this work can offer new references for the safety design of the LIBs ESS.

Use of Chrysosporium/carbon nanotubes for preconcentration of ultra-trace cadmium levels from various samples after extensive studies on its adsorption properties

Carbon nanotubes were used to immobilize Chrysosporium fungus for building an adequate adsorbent to be used as an desirable sorbent for preconcentration and measurement of cadmium ultra-trace levels in various samples. After characterization, the potential of Chrysosporium/carbon nanotubes for the sorption of Cd(II) ions was scrutinized by the aid of central composite design, and comprehensive studies of sorption equilibrium, kinetics and thermodynamic aspects were accomplished. Then, the composite was utilized for preconcentration of ultra-trace cadmium levels, by a mini-column packed with Chrysosporium/carbon nanotubes, before its determination with ICP-OES. The outcomes vouchsafed that (i) Chrysosporium/carbon nanotube has a high tendency for selective and rapid sorption of cadmium ion, at pH 6.1, and (ii) kinetic, equilibrium, and thermodynamic studies showed a high affinity of the Chrysosporium/carbon nanotubes for cadmium ion. Also, the outcomes displayed that cadmium can quantitatively be sorbed at a flow speed lesser than 7.0 mL/min and a 1.0 M HCl solution (3.0 mL) was sufficient to desorbe the analyte. Eventually, preconcentration and measurement of Cd(II) in different foods and waters were successfully accomplished with good accuracy, high precision (RSDs ≤5.65%), and low limit of detection (0.015 μg/L).

Quality by Design Driven Development of Topical Gel Encompassing Papain and Bromelain to Elicit Wound Healing

Abstract: Background: Topical gels are an efficient and targeted therapy for local dermatological problems because they distribute medications effectively and are easy to wipe off the skin. The presented study was aimed to use Quality by Design (QbD) features to develop, optimise, and evaluate a topical gel containing certain plant enzymes for wound healing activity. Objectives: The objective of this study was to use contour plots and multiple linear regression analysis to determine the relative relevance of selected independent variables on dependent variables, as well as to identify the desired zone where the product with required qualities produced. Materials and Methods: Quality Attributes (CQAs) were assigned to the patient-centric Quality Target Product Profile (QTPP). The quantities of chitosan and sodium carboxymethyl cellulose have been selected as Critical Material Attributes (CMA) based on early observations and were employing a 32-full factorial design. CQAS were chosen as viscosity, spreadability, extrudability, and bioadhesive strength, and using multiple linear regression analysis (MLRA) a quantitative association among CQAs and CMAs was observed. Results: The full factorial design aids in predicting the optimal chitosan and sodium carboxy methyl cellulose combination. The numerical response analysis aids in comprehending the impact of various factors on various replies. TGF-O showed higher wound healing activity than control and standard formulations in an excision and incision wound healing model. Conclusion: The current work successfully underlines the possibility of using a quality by design approach to synthesise and create topical gel formulations for plant enzymes in a simple and cost-effective manner. Keywords: Quality by design, Plant enzyme, Factorial design, Wound, Topical gel, Spreadability.

A review on 3D printing maxillofacial surgery: Present work and future prospects

The medical field is only one area that stands to benefit from the rapidly expanding capabilities of 3D printing. In the past several years, advances in technology have allowed oral and maxillofacial surgeons to provide better care for their patients. This article provides a brief summary of the present state of 3D printing in oral and maxillofacial surgery. Patient-specific implants created using computer-assisted design aid in the superior imitation of the original anatomical form. The purpose of this paper is to highlight the present applications of 3D printing in the field of maxillofacial surgery for the treatment of face deformities, aesthetic issues and jaw diseases. The medical and dental fields have seen a surge in interest in the use of additive manufacturing. Their growing use on patients has been attributed to better quality and cost effectiveness. This review simply summarized the numerous methods utilised in Bio printing, as well as their varied benefits and drawbacks. While the results of the preliminary studies have been encouraging, additional study is needed before this technology can be practical and affordable. As this technology is adopted more broadly, many more technological and regulatory hurdles will need to be cleared.

Machine learning as a design aid for electrical machines

Machine learning as a design aid for electrical machines

Axially chiral thermally activated delayed fluorescence emitters enabled by molecular engineering towards high-performance circularly polarized OLEDs

Circularly polarized organic light-emitting diodes (CP-OLEDs), as an emerging display technology, can meet people’s demand for higher quality of visual enjoyment. Wherein, circularly polarized thermally activated delayed fluorescence (CP-TADF) emitters has grown into a promising direction for developing efficient CP-OLEDs, however, how to synergistically advance the chirality and luminescence efficiency is still a tricky dilemma. Herein, a pair of axially chiral CP-TADF enantiomers (−)-(S)/(+)-(R)-ax-DMAC are ingeniously designed by molecular engineering to fine tune electronic and photophysical properties, achieving a major improvement in device performance while inheriting the robust chiroptical feature. Two enantiomers possess excellent TADF feature with a tiny ΔEST of 0.03 eV and high photoluminescence quantum yields (PLQYs) of 90% in doped film, which, moreover, exhibit obvious circularly polarized luminescence (CPL) signals with luminescence dissymmetry factor (|glum|) of about 2.2 × 10−3 in solution. Notably, highly efficient CP-OLEDs employing (−)-(S)/(+)-(R)-ax-DMAC as emitter radiate intense cyan CP light with the prominent maximum external quantum efficiency (EQEmax) of 30.1% and |gEL| of 2.0 × 10−3, which is the highest EQE reported among all CP-TADF emitters with axially chiral emitting skeleton. Interestingly, a remarkably and rarely high luminance of nearly 50,000 cd/m2 is reached though delicate device adjustment, and these findings indicates the collaboration of molecular engineering and sophisticated device design aid in fabricating advanced and efficient CP-OLEDs.

Artificial ecosystem optimization by means of fitness distance balance model for engineering design optimization

Optimization techniques have contributed to significant strides in complex real-world engineering problems. However, they must overcome several difficulties, such as the balance between the capacities for exploitation and exploration and avoiding local optimum. An enhanced Artificial Ecosystem Optimization (AEO) is proposed incorporating Fitness Distance Balance Model (FDB) for handling various engineering design optimization problems. In the proposed optimizer, the combined FDB design aids in selecting individuals who successfully contribute to population-level searches. Therefore, the FDB model is integrated with the AEO algorithm to increase the solution quality in nonlinear and multidimensional optimization situations. The FDBAEO is developed for handling six well-studied engineering optimization tasks considering the welded beam, the rolling element bearing, the pressure vessel, the speed reducer, the planetary gear train, and the hydrostatic thrust bearing design problems. The simulation outcomes were evaluated compared to the systemic AEO algorithm and other recent meta-heuristic approaches. The findings demonstrated that the FDBAEO reached the global optimal point more successfully. It has demonstrated promising abilities. Also, the proposed FDBAEO shows greater outperformance compared to several recent algorithms of Atomic Orbital Search, Arithmetic-Trigonometric, Beluga whale, Chef-Based, and Artificial Ecosystem Optimizers. Moreover, it declares great superiority compared to various reported optimizers.

Investigation of Different Optimization Techniques for Rectenna

Rectenna optimization is important for increasing the efficiency and power output of devices that convert radio frequency (RF) energy into DC power. This can be accomplished by optimizing the design and components used in the rectenna, as well as changing the operating frequency and input power level. Optimization algorithms in rectenna design aid in determining the required geometry parameters of the antenna and rectifier, as well as to find the optimal values of passive components used in the design. This paper investigates various algorithms and optimizers based on these which are used for rectenna optimization.

Feasibility Conditions-Free Prescribed Performance Decentralized Fault-Tolerant Neural Control of Constrained Large-Scale Systems

This article investigates the command filter-based decentralized prescribed performance adaptive fault-tolerant compensation control strategy for uncertain nonlinear large-scale systems subject to asymmetric time-varying full-state constraints. Via integrating the performance function with command filter-based backstepping technique, the prescribed performance control problem is addressed, under which the complexity of controller design is reduced. Under the prescribed performance control framework, the nonlinear transformed function is constructed so as to ensure that the asymmetric time-varying full-state constraints free from feasibility conditions imposed on virtual control signals are not violated. Besides, the effect of infinite number of time-varying actuator faults is compensated with the aid of projection adaption design. Furthermore, based on the piecewise Lyapunov function analysis, it is rigorously testified that entire involved signals are bounded, desired constraints are not breached and tracking errors within the predefined domains. Finally, the effective performances of the developed control algorithm are confirmed by some simulation results.

Numerical simulation of a floating-type point absorber wave energy converter

Wave energy converters (WEC) have been researched extensively to harvest large amounts of untapped ocean renewable energy. Floating-type point absorbers are a type of WEC that converts the ocean wave energy to electrical energy, by utilizing the relative motion of multi-body system mainly consisting of a floating section and a reaction section. The design of floating-type point absorbers is not straightforward and needs special attention to understand the dynamics of the multi-body system, and power take-off (PTO) mechanism placed in the reaction section. The purpose of this study is to develop a numerical simulation tool which can help understand various dynamics of a floating-type WEC and aid in the practical design of PTO systems. The PTO mechanism is represented using a spring-damper system and theoretical modelling of mean absorbed power is presented. The numerical simulation is developed in Orcaflex and is carried out on a demonstration model to show the usefulness of the developed tool. The heave displacement shows the effect of damping (PTO) on the motion response of the floating-type WEC. It is found that the maximization of absorbed power is possible using the developed simulation tool for a specific sea state. Furthermore, the results show the potential use of the developed tool for other floating-type WEC concepts.

Structural analysis and design for a warehouse using STAAD PRO

Aim of this study is to brief about the pre-engineered buildings systems proposed for Warehouse Building. The need for steel building increased lot recently, due to its ease, faster construction and weight by strength ratio than concrete structures. There are so many software to analyse and design the elements but lot of students suffer from insufficient knowledge on calculating loads, load combinations and design parameters. Thus took an initiative to detail the design process with a warehouse study and created a report on its loads acting on the structures like vertical and lateral loads, load combinations with design aids provided in code which includes both ASCE standard and IS standards to design. The results obtained from analysis are within the limits also the designed elements are optimized by trial and error method which includes displacement, axial force, compression, bending along major and minor axis and shear check. Steel member sizes are fixed based on the utilization factor and quantity for steel members arrived. The required bolted or welded connections are designed based on the nodal reactions at structural element intersections. STAAD Pro Software used to construct, analyse and design the model of steel members. Moments are high compared to axial loads many elements are designed as tapered section to reduce the quantity of steel and maximize the efficiency with low cost. The overall steel poundage required is 27 kg/sqm to design the structure. The requirement of purlin weight reduced from 400 kN to 132 kN when replaced Channel section with Z-purlin. In overall, the advantages of Z purlins make them a popular choice for construction projects, particularly for industrial and commercial buildings. The results obtained are recorded for the study.

Rational process design aids biomolecule-derived ethylene polyamine synthesis

In this issue of Chem Catalysis, Vermeeren et al. develop a rich physical, intuitive understanding of the reaction network of ethylene polyamine production via the modeling and holistic synthesis of thermodynamic and kinetic handles hidden within process conditions.

Pengaruh Nozzle dan Pengaruh Variasi Nozzle Terhadap Mini Turbine

Utilizing hydrokinetic energy through water turbines is a promising solution for generating renewable electricity. Water turbines play a crucial role in converting the kinetic energy of water into mechanical energy that can be used to drive electrical generators. This research focuses on the optimal design of a nozzle for water turbines to enhance the performance of hydrokinetic energy. The main objective of this study is to design and analyse an efficient nozzle for water turbines. The nozzle has a critical function in directing the flow of water efficiently and increasing the flow velocity into the water turbine. In the nozzle design, various parameters such as nozzle shape, diameter, angle, and length are considered to achieve optimal performance. The results of this research demonstrate that an optimal nozzle design can significantly enhance the performance of hydrokinetic energy in water turbines. An efficient nozzle design can increase the flow velocity, thereby resulting in increased power output from the turbine. Moreover, the use of genetic algorithms in optimizing the nozzle design aids in efficiently obtaining an optimal design.

Design of titanium uncemented femoral stems for hip prosthesis suitable for the Colombian young adult population

The increase of revision surgeries in hip replacement procedure in Colombian young adult population can be addressed by a new design of femoral stem that reduces stress shielding. A new femoral stem was designed using topology optimization as a design aid to reduce the mass in the femoral stem and its overall stiffness, combined with the theoretical, computational, and experimental assessment of the new design that complies with a static and fatigue safety factor greater than one. The new femoral stem design can be used as a design tool to reduce the number of revision surgeries caused by stress shielding.

Coconut shell biochar application in liquid-solid microextraction of triazine herbicides from multi-media environmental samples

A rapid, fast, widely applicable liquid-solid microextraction and purification method of triazine herbicides (TRZHs) in muti-media samples using salting-out assisted liquid-liquid extraction (SALLE) combined with self-assembled monolithic spin columns-solid phase micro extraction (MSC-SPME) was developed. Environmentally friendly coconut shell biochar (CSB) was used as the adsorbents of MSC-SPME. Ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was the separation and determination method. The adsorption kinetics and isotherms were investigated to indicate the interaction between CSB and TRZHs. Several parameters influencing the liquid-solid microextraction efficiency, such as sample pH, salting-out solution volume and pH, sample loading speed, elution speed, elution ratio and volume of eluent were systematically investigated with the aid of orthogonal design. The whole extraction process was operated within 10 min. Under the optimum extraction and determination conditions, good linearities for three TRZHs were obtained in a range of 0.10–200.00 ng mL−1, with linear coefficients (R2) greater than 0.999. The limits of detection (LODs) and limits of quantification (LOQs) were in the range of 6.99–11.00 ng L−1 and 23.33–36.68 ng L−1, respectively. The recoveries of the three TRZHs in multi-media environmental samples were ranged from 69.00% to 124.72%, with relative standard deviations (RSDs) lower than 0.43%. This SALLE-MSC-SPME-UPLC-MS/MS method was successfully applied to the determination of TRZHs in environmental and food samples and exhibited the advantages of high efficiency and sensitivity, low cost, and environmental friendliness. Compared with the methods published before, CSB-MSC was green, rapid, easy-operated, and reduced the whole cost of the experiment; SALLE combined MSC-SPME eliminated the matrix references effectively; what's more, the SALLE-MSC-SPME-UPLC-MS/MS method could be applied to various sample without complicated sample pretreatment procedure.

Stochastic analysis of excavation-induced wall deflection and box culvert settlement considering spatial variability of soil stiffness

In this study, a three-dimensional (3D) finite element modelling (FEM) analysis is carried out to investigate the effects of soil spatial variability on the response of retaining walls and an adjacent box culvert due to a braced excavation. The spatial variability of soil stiffness is modelled using a variogram and calibrated by high-quality experimental data. Multiple random field samples (RFSs) of soil stiffness are generated using geostatistical analysis and mapped onto a finite element mesh for stochastic analysis of excavation-induced structural responses by Monte Carlo simulation. It is found that the spatial variability of soil stiffness can be described by an exponential variogram, and the associated vertical correlation length is varied from 1.3 m to 1.6 m. It also reveals that the spatial variability of soil stiffness has a significant effect on the variations of retaining wall deflections and box culvert settlements. The ignorance of spatial variability in 3D FEM can result in an underestimation of lateral wall deflections and culvert settlements. Thus, the stochastic structural responses obtained from the 3D analysis could serve as an effective aid for probabilistic design and analysis of excavations.

Density Functional Theory Study of CO2 Hydrogenation on Transition-Metal-Doped Cu(211) Surfaces.

The massive emission of CO2 has caused a series of environmental problems, including global warming, which exacerbates natural disasters and human health. Cu-based catalysts have shown great activity in the reduction of CO2, but the mechanism of CO2 activation remains ambiguous. In this work, we performed density functional theory (DFT) calculations to investigate the hydrogenation of CO2 on Cu(211)-Rh, Cu(211)-Ni, Cu(211)-Co, and Cu(211)-Ru surfaces. The doping of Rh, Ni, Co, and Ru was found to enhance CO2 hydrogenation to produce COOH. For CO2 hydrogenation to produce HCOO, Ru plays a positive role in promoting CO dissociation, while Rh, Ni, and Co increase the barriers. These results indicate that Ru is the most effective additive for CO2 reduction in Cu-based catalysts. In addition, the doping of Rh, Ni, Co, and Ru alters the electronic properties of Cu, and the activity of Cu-based catalysts was subsequently affected according to differential charge analysis. The analysis of Bader charge shows good predictions for CO2 reduction over Cu-based catalysts. This study provides some fundamental aids for the rational design of efficient and stable CO2-reducing agents to mitigate CO2 emission.

Effectiveness of vegetative filter strips for sediment control from steep construction landscapes

Sediment carried off-site by runoff poses a significant water quality threat to receiving water bodies. Best management practices (BMPs) are commonly applied to reduce the impact of runoff on surface water quality. Vegetative filter strips (VFS) are low-cost BMP that often provide significant runoff mitigation in agricultural and urban settings with moderate slopes (<15 %). However, the runoff mitigation effectiveness of VFS under steep, short slopes like those typical of roadway construction is unknown. This study aimed to systematically investigate the efficacy of short (<5 m) and sparse VFS on steep slopes (>15 %). Field experiments were conducted on a steep hillslope (3H:1V, 33.3 %) where three VFS lengths (1.52 m, 3.05 m, and 4.57 m) were monitored during runoff events (10-y, 6-hr) to measure runoff delivery ratio (RDR) and sediment delivery ratio (SDR). The experimental results showed reductions of 60–98 % in runoff and 73–98 % in sediment, confirming the potential efficiency of this BMP in high-sloped conditions like a roadway construction site under certain conditions. The Vegetative Filter Strips Modeling System (VFSMOD) was successfully tested against the observed field values (NSE = 0.98 and 0.89 for RDR and SDR, respectively) and used to explore more scenarios. A wide range of roadway construction settings (VFS size, slope, vegetation density) was investigated with VFSMOD, and two simplified statistical regression equations and nomographs were developed to quantify RDR and SDR based on the simulation results. The proposed equations simplify the complexity of VFS design and can be readily generalized to other locations (rainfall/runoff, soil, vegetation) after reparametrizing coefficients in regression equations based on VFSMOD simulations to obtain new nomographs as a design aid to determine the minimum buffer length for a particular site.

Experimental study on transient flow characteristics in an equal-height-difference passive heat removal system for ocean nuclear power plants

The equal-height-difference passive heat removal system (EHDPHRS) utilizes the ocean as the heat sink for infinite heat dissipation and has broad application prospects in ocean nuclear power plants. However, the equal height difference between the heat source and heat sink is susceptible to severe flow instability. In this study, a fully visualized experimental facility was constructed to analyze the transient flow characteristics in the EHDPHRS. The experimental results revealed three typical two-phase natural circulation flow modes in the EHDPHRS. The formation mechanism of each flow mode was analyzed using thermal–hydraulic parameters. The results revealed that the flow mode is determined by the steam–water direct contact condensation and reverse flow of subcooled water, and both factors promote each other. Moreover, condensation-induced water hammer (CIWH) was found to be the most severe flow instability in the EHDPHRS. CIWH events can lead to violent pressure peaks and reduce the natural circulation capacity. In addition, when the occurrence position of CIWH events is concentrated at the pipe outlet, the influence of CIWH events on the two-phase natural circulation flow capacity gradually decreases. These research results aid in the optimal design of the EHDPHRS and prevention and control of CIWH events.

Enhancing the network lifetime of a wireless sensor network using modified k-means Firefly Optimization

Developing technology including the Internet of Things, digital services, smart microgrids, and machine-to-machine systems encourage the implementation of self-configuring, automated systems in massive wireless sensor networks (WSNs). Effective Power utilization is critical in order to keep a network operational for the maximum possible time. Sensor nodes, which are small, battery-powered devices, are used in WSNs. As a result, one of the significant research issues in improving the lifespan of a WSN is resource management. A modified k-means (Mk-means) algorithm for clustering has been proposed to select Cluster Head (CH) to minimize energy usage of the nodes. Several optimization methods have been suggested in this area to extend the WSN lifetime. Following that, the Firefly Algorithm (FFA) is employed to generate the optimal routing through the CHs to a Base Station (BS), where multiple fitness functions such as residual energy, distance, and routing traffic are taken into account to optimize the FFA. As a result, information transmission among intermediate CHs in a hierarchy cluster-based design aids in lowering node energy usage. The proposed MKMFA (modified k-means Firefly Algorithm) technique’s performance is evaluated with K-means AODV (Ad-hoc On-demand Distance Vector) and IPC-KMAN(Improved Performance Clustering Using Modified K-Means Algorithm in Mobile Adhoc Networks) using network lifetime, throughput, Load Balancing Factor (LBF), and Packet Delivery Ratio (PDR). This work is based on recent advances in WSNs, which include application fields, design parameters, and lifetime prediction designs.