Minimum Energy Requirements Research Articles

A novel semi-active control of an integrated chassis and seat quasi-zero stiffness suspension system for off-road vehicles

This article introduces an innovative semi-active suspension system for off-road vehicles, incorporating a quasi-zero stiffness suspension to enhance driver comfort. The system includes a central pneumatic spring, double-acting pneumatic linear actuators for adjustable stiffness, and magnetorheological dampers for controlled damping. Using Lyapunov stability theory, a static output feedback control law is designed to address uncertainties in road profiles, driver body parameters, and actuator saturation, relying on measured variables as feedback. Performance constraints focus on driver head acceleration, suspension displacement, and dynamic tire load. The control law problem is converted into a convex optimization problem with linear matrix inequalities. The new semi-active QZSS system is theoretically tested via Matlab simulations and validated through hardware-in-the-loop testing. Comparative analysis between passive QZSS and the new semi-active QZSS on different roads, and vehicle speeds closely aligns with simulation results, with minor disparities attributable to network discrepancies and signal interruptions. Impressively, the semi-active QZSS system reduces driver head vertical acceleration between 26.53 and 35.0% compared to passive air QZSS, showing potential for significantly improving ride comfort, reducing vibration transfer, and enhancing driver wellbeing with minimal energy requirement.

Investigation of the Performance of Zero Energy Homes in Hot Climates

Globally, the rate at which buildings use resources and energy has been rising. Due to population growth, rise in living standard, and global warming, strategies for energy conservation have been adopted lately in zero energy buildings. Over the past decade, the energy consumption in constructions has increased at an unprecedented rate. Therefore, it is of great importance to mandate energy rationalization in building construction. This research investigates the impact of applying zero energy concept in homes in Egypt. The study begins by analysing the current situation of the energy sector and existing buildings in Egypt, the NZEB concept is defined and its different aspects are highlighted. Energy simulation by DesignBuilder simulation software is used to evaluate energy performance for a residential single family house model after applying Passive and Active design strategies. A number of energy saving strategies have been examined to optimize the building envelope with minimum energy requirements. The building energy consumption was reduced when various energy efficient strategies were combined. Besides utilizing energy efficient HVAC systems. a solar PV system is installed to meet the reduced energy. The case study was transformed into a zero-energy house. Results show that passive and active techniques can be dependable for steady energy production in buildings in hot dry regions.

Extractive Distillation of Ethanol/Water with 1-Butyl-3-Methylimidazolium Bromide Ionic Liquid as a Separating Agent: Process Simulation

Ethanol purification has become of great interest recently because ethanol can be used as renewable energy, solvent in many industries, and for medicinal purposes. The separation of ethanol from water is challenging because the azeotropic point has appeared in this binary mixture. Extractive distillation technology is one of the most interesting methods to separate ethanol from water due to the competitiveness of its energy consumption and capital investment costs. Ionic liquids such as 1-butyl-3-methylimidazolium bromide [BMIM] [Br], categorized as a green solvent, produce a significant salting-out effect in the ethanol-water system. This makes ionic liquid a promising solvent in ethanol-water separation. This study simulated the extractive distillation of an ethanol-water system with 1-butyl-3-methylimidazolium bromide as a solvent. The simulation and sensitivity analysis were performed on the Aspen Plus Process Simulator to obtain the optimum configuration. The NRTL thermodynamic model was used in this study. The effects of the number of stages (NS), binary feed stage (BFS), entrainer feed stage (EFS), and reflux ratio (RR) on the ethanol concentration with minimum energy requirements were studied. The most optimal configurations to produce a high ethanol concentration with less energy are NS 28, BFS 22, EFS 4, and RR 1.5.

Ultrathin film optical coatings for all-optical mathematical operations with ultrahigh numerical aperture

Optical analog computation is garnering increasing attention due to its innate parallel processing capabilities, swift computational speeds, and minimal energy requirements. However, traditional optical components employed for such computations are usually bulky. Recently, there has been a substantial shift toward utilizing nanophotonic structures to downsize these bulky optical elements. Nevertheless, these nanophotonic structures are typically realized in planar subwavelength nanostructures, demanding intricate fabrication processes and presenting limitations in their numerical apertures. In this study, we present a three-layer thin-film optical coating different from the conventional Fabry–Pérot nanocavity. Our design functions as a real-time Laplacian operator for spatial differentiation, and it remarkably boasts an ultrahigh numerical aperture of up to 0.7, enabling the detected edges to be sharper and have closely matched intensities. We also experimentally demonstrate its capacity for effective edge detection. This ultracompact and facile-to-fabricate thin-film spatial differentiator holds promising prospects for applications in ultrafast optical processing and biomedical imaging.

Bionic Surfaces for Fog Collection: A Comprehensive Review of Natural Organisms and Bioinspired Strategies.

Water scarcity has become a critical global threat, particularly in arid and underdeveloped regions. However, certain insects and plants have evolved the capability to obtain water from fog under these arid conditions. Bionic fog collection, characterized by passive harvesting, minimal energy requirements, and low maintenance costs, has proven to be an efficient method for water harvesting, offering a sustainable water source. This review introduces two superwettable surfaces, namely, superhydrophilic and superhydrophobic surfaces, detailing their preparation methods and applications in fog collection. The fog collection mechanisms of three typical natural organisms, Namib Desert beetles, spider silk, and cactus, along with their bionic surfaces for fog collection devices, are discussed. Additionally, other biological surfaces exhibiting fog transport properties are presented. The main challenges regarding the fabrication and application of bionic fog collection are summarized. Furthermore, we firmly believe that environmentally friendly, low-cost, and stable fog collection materials or devices hold promising prospects for future applications.

Modulator-Dependent Dynamics Synergistically Enabled Record SO2 Uptake in Zr(IV) Metal-Organic Frameworks Based on Pyrene-Cored Molecular Quadripod Ligand.

Developing innovative porous solid sorbents for the capture and storage of toxic SO2 is crucial for energy-efficient transportation and subsequent processing. Nonetheless, the quest for high-performance SO2 sorbents, characterized by exceptional uptake capacity, minimal regeneration energy requirements, and outstanding recyclability under ambient conditions, remains a significant challenge. In this study, we present the design of a unique tertiary amine-embedded, pyrene-based quadripod-shaped ligand. This ligand is then assembled into a highly porous Zr-metal-organic framework (MOF) denoted as Zr-TPA, which exhibits a newly discovered 3,4,8-c woy net structure. Remarkably, our Zr-TPA MOF achieved an unprecedented SO2 sorption capacity of 22.7 mmol g-1 at 298 K and 1 bar, surpassing those of all previously reported solid sorbents. We elucidated the distinct SO2 sorption behaviors observed in isostructural Zr-TPA variants synthesized with different capping modulators (formate, acetate, benzoate, and trifluoroacetate, abbreviated as FA, HAc, BA, and TFA, respectively) through computational analyses. These analyses revealed unexpected SO2-induced modulator-node dynamics, resulting in transient chemisorption that enhanced synergistic SO2 sorption. Additionally, we conducted a proof-of-concept experiment demonstrating that the captured SO2 in Zr-TPA-FA can be converted in situ into a valuable pharmaceutical intermediate known as aryl N-aminosulfonamide, with a high yield and excellent recyclability. This highlights the potential of robust Zr-MOFs for storing SO2 in catalytic applications. In summary, this work contributes significantly to the development of efficient SO2 solid sorbents and advances our understanding of the molecular mechanisms underlying SO2 sorption in Zr-MOF materials.

Heat integration, process design and techno-economic assessment of post-combustion carbon capture using piperazine for large-scale ethylene plant

With the development of increasingly larger ethylene plants and the associated requirement to reduce carbon emissions effectively, there is a growing need to explore approaches that reduce the cost and energy consumption in carbon capture from ethylene plants. In this study, the flue gas heat recovery (FHR) strategy was proposed and implemented for different configurations of piperazine (PZ)-based post-combustion carbon capture (PCC) process applied to an ethylene plant with a capacity of 60,000 t/year. Four different cases of the PZ-based PCC process with or without FHR were simulated in Aspen Plus® V11 to explore the cost reductions and energy saving potential. The advanced flash stripper (AFS) configuration with FHR and absorber inter-cooling achieves a minimum regeneration energy requirement of 2.28 GJ/tonCO2, a reduction of 37.71 % compared to standard PCC configuration using MEA solvent. The economic evaluation was carried out using Aspen Process Economic Analyzer® (APEA). The results show that the carbon capture cost using AFS configuration with FHR and inter-cooling can reduce to 47.27 $/tonCO2, a reduction of 36.76 % against the standard PCC process using MEA. The proposed technology presents significant technical and economic benefits for the large-scale deployment of carbon capture for ethylene plants.

Optimal protocols for entangling gates in N-qubit atomic systems

We use a novel optimization procedure that includes the temporal and spatial parameters of the pulses acting on arrays of trapped neutral atoms to prepare entangling gates in N-qubit systems. The spatiotemporal control allows treating a denser array of atoms, where each pulse acts on a subset of the qubits, potentially allowing to speed up the gate operation by two orders of magnitude by boosting the dipole-blockade between the Rydberg states. Studying the rate of success of the algorithm under different constraints, we evaluate the impact of the proximity of the atoms and, indirectly, the role of the geometry of the arrays in three and four-qubit systems, as well as the minimal energy requirements and how this energy is used among the different qubits. Finally, we characterize and classify all optimal protocols according to the mechanism of the gate using a quantum pathway analysis.

Mass-Indices (B-Values) of Legumes, Tuber and Sea Food for Mass-Size Reduction Operations

In an effort to easily use the Orua Antia’s energy and power equations to determine the minimum comminution energy and power requirements of a given material; the mass Index being a constant in these equations is necessary to be provided for materials that could be subjected to comminution. In this study, the mass indices of some selected food materials such as cassava, yam, crayfish, beans and soybeans which finds applications in food industries were evaluated using static impact force technique coupled with graphical and computational approaches. In graphical method Equation 17 obtained from energy expression for mass-size reduction Equation 14 was employed; while Equation 16 which is a combination of Equation 14 and the potential energy Equation 15 was used in the computational method. Also the relative errors of mass indices obtained from these two methods were evaluated. Results showed that computational or graphical method could be used to obtain the mass index of each selected material. It was observed that moisture content had little influence on the value of mass index. Hence, the average mass index per selected food type within its percentage moisture content wet basis range could be utilized in the minimum comminution energy and power Equations 4 to 6 and 12 to 13 respectively, via the equations constants as applicable and expressed as Equations 9, 10 and 11. Further analysis revealed that the average mass indices were 1.71230.5835, 1.89150.6377,20.27043.0846, 18.19601.0337 and 23.77912.3094 for cassava, yam, crayfish, beans and soy beans respectively.

Estimation of Mass Indexes (B-Values) for Use in Predicting the Minimum Energy and Power Requirements for Mass-Size Reduction Operations of Some Cereals

In an attempt to predict easily the minimum energy and power requirements necessary to achieve the expected size reduction of materials using the recently developed Orua Antia’s energy and power equations; it is essential that constant(s) in the equation should be readily available for usage. Therefore in this study, the evaluation of a constant termed mass index (B- Value) for mass-size reduction operations was carried out on cereals such as corn, wheat, sorghum, and millet that find various applications in food industries. Equations 17 and 18b were employed to evaluate mass indexes using the principles of static impact force. Relative errors (RE) of mass indexes obtained from these two equations were assessed. Results revealed that Equation 17 or 18b could be used to evaluate the mass indexes. More so, for each selected cereal the mass index was observed to vary slightly with moisture content %wb. Hence, the average mass index per cereal type per moisture content range may be used in Orua Antia’s energy Equations 5 to 9 to predict the minimum energy and power requirements of the selected cereal when subjected to mass-size reduction operations. The average mass-indexes obtained were 20.9915± 0.4198; 27.6679± 0.6506; 24.9379±20.5454 and 24.523±3.7571Kg(1⁄2) m2s-2for corn, wheat, sorghum, and millet respectively.

An Improved Search Algorithm for WSN with Charging Nodes

The existing semi-centralized stochastic election approach, Stochastic Election of Appropriate Range Cluster Heads (SEARCH) is analyzed and features are improved which, boasts low time cost, improved stable period, and eliminates the unfavorable scenario, that no cluster head emerges during some specific rounds. However, the implementation of SEARCH in WSNs with solar charging nodes offers very marginal improvement in a stable period. This proves the inefficiency of the algorithm in handling these charging nodes. The improvement offered aims to make the algorithm, more energy aware and hence comparatively well organized in handling the charging nodes in the network. This improvement, equipped with dynamic tracking of instantaneous node energy shows a promising way to extend clustering algorithms to networks with chargeable nodes. In addition, the existing SEARCH algorithm’s cluster head election procedure lacks a futuristic view of the minimum energy requirement for successful operation throughout an entire round. Intermediate cluster head death can be detrimental, to network performance by paralyzing the corresponding clusters, resulting in total data transmission failure of all nodes in that cluster. Implementing the improved SEARCH algorithm drastically reduces the bit loss by 95%, with increasing the transmitted bits successfully by 4%. The overall lifetime of the WSN improves by around 30% and the number of cluster heads dying prematurely in the middle of round operation is reduced by 89%. This paper analyzes and refines a current clustering algorithm, thereby promisingly enhancing its capacity to boost the overall network performance.

Effects of fuel Lewis number on the minimum ignition energy and its transition for turbulent homogeneous fuel–air mixtures

The effects of fuel Lewis number on the minimum ignition energy (MIE) requirements for ensuring successful thermal runaway, and self-sustained flame propagation have been analysed for forced ignition of homogeneous fuel–air mixtures under decaying turbulence for a wide range of initial turbulence intensities using three-dimensional direct numerical simulations. The minimum energy demand for ensuring self-sustained flame propagation has been found to be greater than that for ensuring only thermal runaway irrespective of its outcome for large turbulence intensities, and the minimum ignition energy increases with increasing rms turbulent velocity irrespective of the fuel Lewis number. The MIE values have been found to increase more sharply with increasing turbulence intensity beyond a critical value for all fuel Lewis numbers considered here. The variations of the normalised MIE (MIE normalised by its laminar value) with increasing turbulence intensity beyond the critical point follow a power-law and the power-law exponent has been found to increase with an increase in fuel Lewis number. This behaviour has been explained using a scaling analysis. The stochasticity associated with forced ignition has been demonstrated by using different realisations of statistically similar turbulent flow fields for the energy inputs corresponding to the MIE and successful outcomes are obtained in most instances, justifying the evaluation of the MIE values in this analysis.

A Neurodynamic Approach for SWIPT Power Splitting Optimization

Simultaneous wireless information and power transfer (SWIPT) systems using energy from RF signals can effectively solve the energy shortage of wireless devices. However, the existing SWIPT optimization methods using numerical algorithms are difficult to solve the non-convex problem and to adapt to the dynamic communication circumstances. In this paper, a duplex neurodynamic optimization method is used to address the SWIPT system’s power partitioning issue. The information rate maximization problem of the SWIPT system is framed as a biconvex problem. A duplex recurrent neural network is used to concurrently execute local search and update the initial state of the neural network by a particle swarm optimization method to get the global optimum. The experimental results demonstrate that the duplex neurodynamic-based SWIPT system maximizes information rate while satisfying the minimal harvesting energy requirement in a variety of channel states.

Econometric study of the number of undernourished people in Colombia from 2000 to 2021

The importance of food (in)security has been one of the United Nations Sustainable Development’s main goals. Over 828 million people worldwide cannot acquire enough food to meet the minimum daily dietary energy requirements (undernourished). Therefore, the present study examines the factors that affect the number of undernourished people in Colombia by assessing macroeconomic data for the period 2000-2021 including gross domestic product (GDP) per capita, unemployment, and inflation rates. A quantitative, empirical, correlation design was used to examine and describe the relationship among the variables. The findings showed that the proposed variables presented the correct signs, were statistically significant, and were in line with the economic theory. Thus, the study concluded that although income shocks brought on by inflation and unemployment undoubtedly impact household food (in)security, other factors must also be considered for policy and practice to effectively reduce food insecurity for households.

Dynamic Fracture and Crack Arrest Toughness Evaluation of High-Performance Steel Used in Highway Bridges.

Impact energy tests are an efficient method of verifying adequate toughness of steel prior to it being put into service. Based on a multitude of historical correlations between impact energy and fracture toughness, minimum impact energy requirements that correspond to desired levels of fracture toughness are prescribed by steel bridge design specifications. Research characterizing the fracture behavior of grade 485 and 690 (70 and 100) high-performance steel utilized impact, fracture toughness, and crack arrest testing to verify adequate performance for bridge applications. Fracture toughness results from both quasi-static and dynamic stress intensity rate tests were analyzed using the most recently adopted master curve methodology. Both impact and fracture toughness tests indicated performance significantly greater than the minimum required by material specifications. Even at the AASHTO Zone III service temperature, which is significantly colder than prescribed test temperatures, minimum average impact energy requirements were greatly exceeded. All master curve reference temperatures, both for quasi-static and dynamic loading rates, were found to be colder than the Zone III minimum service temperature. Three correlations between impact energy and fracture toughness were evaluated and found to estimate reference temperatures that are conservative by 12 to 50 °C (22 to 90 °F) on average for the grades and specimen types tested. The evaluation of two reference temperature shifts intended to account for the loading rate was also performed and the results are discussed.

Minimum Energy Requirements of Pipeline Pumping

This paper establishes the minimum amount of energy required by a simple system, a benchmark established on the basis of current technology and the requirements by energy regulators, weighting costs, and efficiency. The first step is to normalize the energy intensity (kWh/m3), which is the quotient between the energy consumed and the volume pumped, with the geometric gradient. The new normalized parameter is more objective than the commonly standardized one with the pumping head due to its dependence on friction. In addition, it makes it possible to naturally disaggregate energy needs (in useful and dissipated energy during transport) to establish a target energy intensity and evaluate existing savings. The quotient between energy intensities (actual and target) allows qualifying transport efficiency. At the same time, it permits extending the policy of energy labeling to pressurized water transport, which has been proven to be a successful energy efficiency strategy.

Optimization of well design and bit selection to reduce drilling cost and improve efficiency

Drilling oil and gas well at the lowest possible cost has always been paramount to drilling engineers in order to achieve their company’s objectives. However, in most cases, this is not attained because of the problem associated with the drilling bit selection, drilling design and drilling parameters. As it is a fact that the large chunk of the cost of bringing oil and gas to the surface is always incurred at the drilling/completion stage. In this study, data were gathered from selected 5 Niger Delta wells and were analyzed. These data were used to calculate the costs of drill bits and the bits with lowest costs. The drilling cost was studied and optimization procedure employed to select the best bit from well data obtained. Bits RSS1, RSS2, RSS3, RSS4, GX1 and BX1 that were used to drill, were select for this study. Drilling cost relation was to ascertain the most cost-effective one. Drilling with bit RSS1 showed the lowest cost possible, therefore RSS1 was said to be optimized. In consideration of the drill bit specific energy (SE) with respect to the ROP, RSSI showed a low value, indicating minimal energy requirement for the successful drilling operation. Conclusively, the SE is a function of ROP and ROP was highest at the minimum SE. Optimized where the drilling cost was minimum.

Assessment of waste heat recovery potential in greenhouse ventilation systems using dynamic pinch analysis

A major factor contributing to the energy efficiency of greenhouses is ventilation losses. The present paper aims at developing a systematic method based on dynamic Pinch Analysis (PA) approach to investigate the heat recovery potential of greenhouse ventilation systems. The heat integration possibility of ventilation waste heat is studied over the course of a year for a greenhouse located in Saskatoon, Canada. The analysis is conducted for a system including a heat pump connected to seasonal heat storage, and an air handling unit. In the first step, a greenhouse climate model is developed to provide the required input data for the PA (i.e., greenhouse thermal and dehumidification loads). Then, a clustering technique is proposed to reduce the heat integration scenarios to a manageable size by limiting the analysis to a set of typical days representing the whole year. Finally, dynamic energy targeting is performed using the composite curves concept of PA to find the maximum heat recovery and minimum energy requirements of the greenhouse. The results showed 55% heat recovery potential for the greenhouse under study. Application of the proposed method can help to find realistic estimations on feasible heat recovery ratios and utility and equipment costs in the early stages of the greenhouse design.

Circular Economy and Green Chemistry: The Need for Radical Innovative Approaches in the Design for New Products

The idea of a circular economy (CE) has gained ground over the past ten years as a means of addressing sustainable development and getting around the limitations of the current and linear dominant production and consumption patterns. The primary goal of a CE is to encourage the adoption of closing-the-loop production methods to improve resource use efficiency, modify chemical processes, and increase product and material lifespan. According to the 2030 Agenda for Sustainable Development, which focuses on 17 Sustainable Development Goals, 14 of which call for the appropriate application of green chemistry (GC) concepts and patterns, the role that chemistry may play in the shift toward more sustainable models is critical. By serving as the foundation for novel products made from renewable feedstocks and designed to be reused, recycled, or recovered with the associated minimum energy requirements, green and sustainable chemistry could be the key to unlocking the economic potential of the CE toward new product design and ultimately solving waste management problems. The aim of this perspective paper, while using a variety of literature sources, is to essentially capture the main issues associated with the CE and GC paradigms and how these two approaches can merge toward sustainable business models and the production of new materials. This integration focuses on reducing waste, conserving resources, and minimizing negative environmental impacts, while also considering economic viability. However, the obstacles to achieving implementation of the CE and GC principles are investment, environmental education, and legislation. To advance toward the circular economy and green chemistry, international agreements should be reconsidered to provide an appropriate framework, including the creation of incentives for businesses and individuals to adopt circular practices, the establishment of education programs to promote the benefits of circular practices, and the development of regulations to support the transition to sustainable production and consumption patterns.

Reducing global inequality to secure human wellbeing and climate safety: a modelling study

For decades, climate researchers have highlighted the unprecedented emissions reductions necessary if we are to meet global mitigation ambitions. To achieve these reductions, the climate change mitigation scenarios that dominate the literature assume large-scale deployment of negative-emissions technologies, but such technologies are unproven and present considerable trade-offs for biodiversity and food systems. In response, energy researchers have postulated low energy demand scenarios as alternatives and others have developed models for estimating the minimum energy requirements for the provision of decent material living standards considered essential for human wellbeing. However, a key question that our study aims to explore is how a climate-safe, low energy demand future, and universal decent living could be achieved simultaneously, given the magnitude of current global inequalities in energy consumption and technological access. In this modelling study, we combined data that described current global and regional inequalities in energy consumption with scenarios for low energy demand in 2050, and compared the resulting distributions with estimates of decent living energy, drawing all of this data from published academic literature. Using a threshold analysis, we estimated how much of the 2050 global population would fall below the minimum energy required to support human wellbeing if a low energy demand pathway was followed but inequalities in energy consumption remained as wide as they currently are. We then estimated the reductions in energy inequality and increases in technological equity that were required to ensure that no one falls below decent living energy in a climate-safe future. Finally, we speculated about the implications for global income inequalities. We found that unprecedented reductions in income and energy inequalities are likely to be necessary to simultaneously secure a climate-safe future and decent living standards for all. If global energy use is reduced enough to ensure climate safety, but the extent of energy inequality remains as it is today, more than 4 billion people will not have access to decent living energy. To avoid this occurrence, after remaining essentially flat for 150 years, the Gini coefficient for income inequality globally might have to fall by a factor of two (ie, to a lower extent than for some of the most egalitarian European countries) and at a rate of reduction more than double that observed in the so-called golden age of capitalism. In the Global South (South America, Central America, south Asia, southeast Asia, east Asia, the Middle East, and Africa) even greater reductions in inequality would be required, unless the average living standards in the Global North (North America, Europe, Australasia, central Asia, and Japan) and in the Global South fully converged, which would require even more substantial reductions in consumption in the Global North than low energy demand scenarios assume. Resolving the contradiction between the current global economic system (with its inherent inequalities) and the need for planetary and human health necessitates transformational change. Reflecting on the limitations of our analysis, we discuss four ways that these global challenges could be met without the need for such drastic reductions in inequality. The Centre for Research into Energy Demand Solutions and the Leverhulme Trust.