Energy Research Articles

Advanced analysis of the adsorption mechanism for sweet odorant on mouse and human olfactory receptors via statistical physics theory

In this work, the one layer statistical physics model (M1) was applied to more deeply comprehend the phenomenon of adsorption, which is putatively involved in the olfactory sensation of acetophenone (AP) on mouse and human olfactory receptors. On one hand, the proposed model was utilized to microscopically characterize the studied olfactory systems in order to obtain advanced stereographic and energetic information concerning the studied olfactory systems in terms of a molecular view point. Based on the values of the number of acetophenone molecules docked on mouse and human binding sites n, it was found that the studied sweet odorant was linked with a mixed orientation. Energetically speaking, the values of the molar adsorption energy ΔE1, which ranged from 11.81 to 17.67 kJ/mol for mouse olfactory receptors (Olfr62, Olfr1093, Olfr1094, Olfr895, and Olfr876) and from 14.66 to 20.58 kJ/mol for human olfactory receptors (OR2C1, OR1A1, and OR2J2), indicated that acetophenone molecules were exothermically physisorbed. The adsorption energy distributions relative to AP may also be estimated to understand the olfactory sense in the investigated olfactory systems via the calculation of olfactory bands (i. e., AED bands), which may be defined between 4.80 and 27 kJ/mol and between 5.50 and 27 kJ/mol for mouse and human olfactory receptors, respectively. On the other hand, M2 was used to determine three thermodynamic potentials (i.e., the internal energy, the Gibbs free energy, and the adsorption entropy), which macroscopically characterized the investigated olfactory systems via a detailed thermodynamic analysis of the different olfactory systems.

Many-Body-Expansion Based on Variational Quantum Eigensolver and Deflation for Dynamical Correlation.

In this work, we utilize the framework of many-body expansion (MBE) to decompose electronic structures into fragments by incrementing virtual orbitals, aiming to accurately solve the ground and excited state energies of each fragment using the variational quantum eigensolver and deflation algorithms. While our approach is primarily based on unitary coupled cluster singles and doubles (UCCSD) and its generalization, we also introduce modifications and approximations to conserve quantum resources in MBE by partially generalizing the UCCSD operator and neglecting the relaxation of the reference states. As a proof of concept, we investigate the potential energy surfaces for the bond-breaking processes of the ground state of two molecules (H2O and N2) and calculate the ground and excited state energies of three molecules (LiH, CH+, and H2O). The results demonstrate that our approach can, in principle, provide reliable descriptions in all the tests including strongly correlated systems when appropriate approximations are chosen. Additionally, we perform model simulations to investigate the impact of shot noise on the total MBE energy and show that precise energy estimation is crucial for lower-order MBE fragments.

Convective instability of Ekman boundary layer flow of a Newtonian fluid over a stretchable rotating disk

ABSTRACT This paper examines a linear convective instability of an incompressible, Newtonian, viscous fluid rotating over a stretchy spinning disk in an Ekman boundary layer flow. First time in the literature, a numerical analysis of impacts of the stretching mechanism on the stability of the Ekman flow in the presence of the Coriolis force has been carried out, where the bottom disk is allowed to uniformly extend in radial direction. The von Kármán similarity transformations have been used to convert the governing equations of motion into a system of non-linear coupled ordinary differential equations (ODEs) in non-dimensional variables. Then velocity profiles of the flow have been obtained by numerically solving these dimensionless ODEs. The neutral stability curves were then obtained by performing a linear stability analysis for the convective mechanism by using the Chebyshev collocation method. Surface stretching has a globally stabilizing influence on both Type-I and Type-II instability modes of the Ekman flow, according to the stability curves. Then, the result established from the stability curves has been verified by calculating total kinetic energy change due to induced perturbations in the flow system. y.

Cluster perturbation theory IX: Perturbation series for the coupled cluster singles and doubles ground state energy.

In this paper, we develop and analyze a number of perturbation series that target the coupled cluster singles and doubles (CCSD) ground state energy. We show how classical Møller-Plesset perturbation theory series can be restructured to target the CCSD energy based on a reference CCS calculation and how the corresponding cluster perturbation series differs from the classical Møller-Plesset perturbation series. Subsequently, we reformulate these series using the coupled cluster Lagrangian framework to obtain series, where fourth and fifth order energies are determined only using parameters through second order. To test the methods, we perform a series of test calculations on molecular photoswitches of both total energies and reaction energies. We find that the fifth order reaction energies are of CCSD quality and that they are of comparable accuracy to state-of-the-art approximations to the CCSD energy based on local pair natural orbitals. The advantage of the present approach over local correlation methods is the absence of user defined threshold parameters for neglecting or approximating contributions to the correlation energy. Fixed threshold parameters lead to discontinuous energy surfaces, although this effect is often small enough to be ignored, but the present approach has a differentiable energy that will facilitate derivation and implementation of gradients and higher derivatives. A further advantage is that the calculation of the perturbation correction is non-iterative and can, therefore, be calculated in parallel, leading to a short time-to-solution.

Derivation of the Schrödinger equation from QED

The Schrödinger equation relates the emergent quantities of wavefunction and electric potential and is postulated as a principle of quantum physics or obtained heuristically. However, physical consistency requires that the Schrödinger equation is a low-energy dynamical condition we can derive from the foundations of quantum electrodynamics. Due to the small value of the electromagnetic coupling constant, we show that the electric potential accurately represents the contributions of intermediate low-energy photon exchanges. Then, from the total nonrelativistic energy relation, we see that the dominant term of the electron wavefunction is a superposition of plane waves that satisfies the Schrödinger equation. Our derivation shows that the Schrödinger equation is not an energy conservation relation because its middle term does not represent the electron kinetic energy as assumed. We analyze the physical content of the Schrödinger equation and verify our assessments by calculating and evaluating the physical quantities in the ground state of the hydrogen atom. Furthermore, we explain why nonrelativistic quantum dynamics differs from classical dynamics. Undergraduate students can follow the derivation because it involves fundamental physical concepts and mathematical expressions, and we explain every step.

Intraocular pressure profile following selective laser trabeculoplasty in pigmentary and primary open-angle glaucoma.

To compare the intraocular pressure (IOP) profile and the incidence of IOP spikes following selective laser trabeculoplasty (SLT) between pigmentary glaucoma (PG) and primary open-angle glaucoma (POAG). Retrospective comparative study of 65 PG eyes of 51 patients matched with 65 POAG eyes of 65 patients who received SLT. Matching was done based on age, gender, glaucoma severity, pre-laser IOP, and number of medications. Post-SLT IOP spike was defined as IOP elevation ≥5mmHg, 30-45 min after the laser. In PG and POAG groups, the average age was 62.33 ± 9.18 and 62.58 ± 9.19 years (p = 0.95). The glaucoma severity (p = 0.708), baseline IOP (PG = 21.61 ± 1.34mmHg vs. POAG = 21.13 ± 5.09mmHg, p = 0.943), and number of topical glaucoma medications(PG = 2.34 ± 1.34 vs. POAG = 2.1 ± 1.41, p = 0.342) were comparable. More PG patients were on oral acetazolamide (PG = 26.15% vs. POAG = 1.5%, p < 0.001). Average logMAR visual acuity was significantly higher in the POAG group (0.207 ± 0.3 vs. 0.192 ± 0.37, p = 0.012). Eyes with PG received lower laser energy (POAG = 63.65 ± 22.03 mJ vs. PG = 43.71 ± 25.68 mJ, p < 0.001). IOP spikes were recorded in 5 PG eyes (7.6%) and none in the POAG group (p = 0.058). Failure rates were similar (PG = 50.7% and POAG = 43.1%, p = 0.205). In multivariable analysis, only pre-laser IOP (coefficient = 2.154 [CI: 0.765-3.543], p = 0.003) was a significant predictor of IOP change percentage after 12 months. SLT was comparably effective in both PG and POAG. IOP spikes were observed only in the PG group, though the total laser energy was lower in this group compared with POAG.

Linking energy-based circularity with environment in high-income economies.

A circular economy is a regenerative approach that emphasizes resource efficiency, waste reduction, and the reuse of materials for a sustainable world. By adopting circular practices, we can reduce the negative impact of traditional linear economic models on the environment. According to the International Renewable Energy Agency (IRENA), the world is generating only 26% of total energy production from circular practices, which positively impacts environmental health. Therefore, this study aims to evaluate the empirical estimation of circular practices regarding energy on the environment. The current study focuses on the association between the circular economic index, economic growth, trade, digitization, energy use, and the financial development index on the environment in 29 high-income countries from 1990 to 2019. The study employs the second-generation econometric technique Driscoll-Kraay to empirically estimate the association among the variables of interestafter confirming cross-sectional dependencywithin the data set. The study findings reveal that circular practices improve high-income countries' environmental conditions. Furthermore, the study confirms the association between economic growth, financial development index, energy use, trade, and digitization on the environment, and it leads to a more sustainable situation. Policies are drawn based on findings for policymakers toward a sustainable world.

Analysis of Pore Characterization and Energy Evolution of Granite by Microwave Radiation

To study the dynamic response of granite to different levels of microwave power, an intelligent microwave rock-breaking instrument is used to irradiate different power from three directions. The servo universal testing machine is used to carry out a uniaxial compression test on the granite after microwave damage to analyze the strength damage characteristics and the degree of pore damage. Pore fractal characteristics are analyzed based on nuclear magnetic resonance to establish the microwave damage degradation model. In parallel, the energy evolution process of granite under the influence of various power levels is analyzed using the theory of energy dissipation. Simultaneously, based on the energy dissipation theory, we analyze the energy evolution process of granite under the action of different powers. The results show that with higher microwave power, the peak strength and modulus of elasticity show a linear decreasing law. The degree of fragmentation is more obvious, showing the damage characteristics with two big ends and little in the middle. The higher the power, the greater the porosity and the more sensitive the micropore becomes to microwaves. Additionally, the damage degradation model established to evaluate the microwave damage of the rock showed that it was feasible. The higher the power, the lower the total energy, elastic energy, and dissipation energy, and the granite is gradually transformed from elastic deformation to plastic deformation. The elastic energy ratio decreases, the dissipation energy ratio increases, and the degree of damage becomes more and more serious. This study provides theoretical support for exploring the mechanical behavior and mechanism of microwave-assisted rock breaking and is of great practical significance.

Dynamic Properties of Double Porosity/Permeability Model

Abstract Understanding fluid movement in multi-pored materials is vital for energy security and physiology. For instance, shale (a geological material) and bone (a biological material) exhibit multiple pore networks. Double porosity/permeability models provide a mechanics-based approach to describe hydrodynamics in aforesaid porous materials. However, current theoretical results primarily address steady-state response, and their counterparts in the transient regime are still wanting. The chief aim of this paper is to fill this knowledge gap. We present three principal properties—with rigorous mathematical arguments—that the solutions under the double porosity/permeability model satisfy in the transient regime: backward-in-time uniqueness, reciprocity, and a variational principle. We employ the “energy method”—exploiting the physical total kinetic energy of the flowing fluid—to establish the first property and Cauchy–Riemann convolutions to prove the next two. The results reported in this paper—qualitatively describe the dynamics of fluid flow in double-pored media—have (a) theoretical significance, (b) practical applications, and (c) considerable pedagogical value. In particular, these results will benefit practitioners and computational scientists in checking the accuracy of numerical simulators. The backward-in-time uniqueness lays a firm theoretical foundation for pursuing inverse problems in which one predicts the prescribed initial conditions based on data available about the solution at a later instance.

Modelling and optimizing microgrid systems with the utilization of real-time residential data: a case study for Palapye, Botswana

Microgrids are becoming a realistic choice for residential buildings due to the increasing need for affordable and sustainable energy solutions in developing nations. Through modeling and simulation, the main goal is to evaluate the viability and performance of a solar microgrid system. Residential load modeling is used, which is vital to developing an effective Energy Management System (EMS) for the microgrid. A residential household’s load metering data is examined using statistical methods, including time series and regression analysis. For the residential community load in this research, Proportional-Integral-Derivative (PID) controllers and Fuzzy Logic Controllers (FLC) are used to generate the necessary Direct Current (DC) microgrid voltage. The simulation research shows that FLC have benefits over PID controllers. The FLC technique performs better at reducing total harmonic distortion, which improves the microgrid system’s overall power quality. The Seasonal Autoregressive Integrated Moving Average (SARIMA) model was found to be the most appropriate and reliable model for the dataset after the performance of the models was evaluated using the metrics. The optimization results also showed that FLC optimization improves the microgrid system’s stability. The exponential Gaussian process regression (GPR) produced the highest R-squared measure of 0.49 and RSME measure of 7.9646, making it the best goodness fit for modeling the total daily energy usage and the peak daily usage.

Energetic Valorization of the Innovative Building Envelope: An Overview of Electric Production System Optimization

The world population increased from 1 billion in 1800 to around 8 billion today. The Population Division of the United Nations predicts a global population of approximately 10.4 billion people by the end of the century. That represents over 2 billion more people. Moreover, the global community is currently experiencing a precarious state due to the enduring repercussions of the COVID-19 pandemic across all sectors, including energy. Given the rising global population and the limited availability of primary energy resources, we must reach a balance between the demands of a growing human population and the planet’s carrying capacity. The dreadful conflict in Ukraine has precipitated an enormous energy crisis. This crisis has served as a warning to the world population of how much it depends on this resource to survive. In France, the building sectors, specifically residential and tertiary, account for 45% of the total final energy consumption. It is the first energy consumer of the country and one of the most polluting (i.e., about 34% of CO2 emitted by France). Consequently, we must consider alternative energy resource forms (i.e., substitution energy forms). Harvesting energy from the building envelope may be a viable technique for partially satisfying the electricity demands of building users. In this context, scientific research offers considerable potential for developing more innovative and efficient systems. This article aims to review the state-of-the-art of advances on the subject to orient and further optimize energy production systems, particularly electricity. This work addresses several points of view: it discusses the overall backdrop of the present study and introduces the subject; details the research strategy and procedures used to produce this paper; develops the state-of-the-art on the potential for generating or recovering power from the building envelope; presents the SWOT analysis of the earlier-described systems. Finally, it concludes by offering findings and viewpoints.

A New Model for Building Energy Modeling and Management Using Predictive Analytics: Partitioned Hierarchical Multitask Regression (PHMR)

Buildings are major consumers of energy, accounting for a significant proportion of total energy use worldwide. This substantial energy consumption not only leads to increased operational costs but also contributes to environmental concerns such as greenhouse gas emissions. In the United States, building energy consumption accounts for about 40% of total energy use, highlighting the importance of efficient energy management. Therefore, accurate prediction of energy usage in buildings is crucial. However, accurate prediction of building energy consumption remains a challenge due to the intricate interaction of indoor and outdoor variables. This study introduces the Partitioned Hierarchical Multitask Regression (PHMR), an innovative model integrating recursive partition regression (RPR) with multitask learning (hierML). PHMR adeptly predicts building energy consumption by integrating both indoor factors, such as building design and operational variables, and outdoor environmental influences. Rigorous simulation studies illustrate PHMR’s efficacy. It outperforms traditional single-predictor regression models, achieving a 32.88% to 41.80% higher prediction accuracy, especially in scenarios with limited training data. This highlights PHMR’s robustness and adaptability. The practical application of PHMR in managing a modular house’s Heating, Ventilation, and Air Conditioning (HVAC) system in Spain resulted in a 37% improvement in prediction accuracy. This significant efficiency gain is evidenced by a high Pearson correlation coefficient (0.8) between PHMR’s predictions and actual energy consumption. PHMR not only offers precise predictions for energy consumption but also facilitates operational cost reductions, thereby enhancing sustainability in building energy management. Its application in a real-world setting demonstrates the model’s potential as a valuable tool for architects, engineers, and facility managers in designing and maintaining energy-efficient buildings. The model’s integration of comprehensive data analysis with domain-specific knowledge positions it as a crucial asset in advancing sustainable energy practices in the building sector.

Higher total energy costs strain the elderly, especially low-income, across 31 developed countries

Addressing the total energy cost burden of elderly people is essential for designing equitable and effective energy policies, especially in responding to energy crisis in an aging society. It is due to the double impact of energy price hikes on households-through direct impact on fuel bills and indirect impact on the prices of goods and services consumed. However, while examining the household energy cost burden of the elderly, their indirect energy consumption and associated cost burden remain poorly understood. This study quantifies and compares the direct and indirect energy footprints and associated total energy cost burdens for different age groups across 31 developed countries. It reveals that the elderly have larger per capita energy footprints, resulting from higher levels of both direct and indirect energy consumption compared with the younger age groups. More importantly, the elderly, especially the low-income elderly, have a higher total energy cost burden rate. As the share of elderly in the total population rapidly grows in these countries, the larger per capita energy footprint and associated cost burden rate of elderly people would make these aging countries more vulnerable in times of energy crises. It is therefore crucial to develop policies that aim to reduce energy consumption and costs, improve energy efficiency, and support low-income elderly populations. Such policies are necessary to reduce the vulnerability of these aging countries to the energy crisis.

Mechanical response and energy evolution of interbedded shales subjected to multilevel constant/increasing-amplitude cyclic loading

This study aims to investigate the effects of fatigue loading paths and interbed structure on the mechanical properties and energy evolution characteristics of shales. In the experiments, shale specimens with five types bedded angles (0°, 30°, 45°, 60°, 90°) were prepared, and multilevel constant-amplitude fatigue loading test (MCFT) and multilevel variable-amplitude fatigue loading test (MVFT) were performed. Results indicated that shale's fatigue behaviors were highly affected by the bedding plane angles and the cyclic loading paths. Specifically, with the increasing of bedding angle, the peak strength, total dissipated energy, and total input energy of the shales showed a "U" trend, the ultimate macro-damage mode changed from mixed tension-shear failure to failure along the bedding planes, and the damping ratio firstly increased and then decreased. Test schemes of stepwise increase of the lower stress limit or keeping it constant were the differences between MCFT and MVFT, which significantly influenced the evolution of irreversible deformation of shales. Compared to MVFT, the shale in MCFT displayed reduction in peak strength in the range of 4.3% to 23.9%, greater and more drastic variations in elastic modulus and damping ratios, dissipative energy and elastic strain energy were relatively low by an order of magnitude.

Energy Use Pattern and Economic Analysis of Fluted Pumpkin (Telfairia occidentalis) Production in Tillage Methods

The study investigates the energy use pattern and economic analysis of fluted pumpkin production in tillage methods (traditional, reduced-conventional and conventional). Human power, machinery, diesel fuel, fertilizers, seed and pesticides energy inputs were used during the cultivation of fluted pumpkin. Input and output energy analysis method was used to estimate the input and output energy in each of the tillage methods during the production of fluted pumpkin. The energy indices of fluted pumpkin production determined were; energy efficiency, energy productivity, specific energy, net energy and energy efficiency index. The economic analysis of fluted pumpkin production in terms of total cost of production, gross monetary return, net monetary return and cost benefit ratio for the three tillage methods used were determined. The total energy required per hectare in traditional, reduced-conventional and conventional tillage methods were 6899.90, 9206.16 and 10176.84 MJ/ha, while the output energy were found to be 8912.48, 12297.8 and 12297.8 MJ/ha, respectively. The energy efficiency, energy productivity and net energy gain of 3.97, 1.50 and 1.20; 0.76, 0.86 and 0.71 MJ/kg; 1.32, 1.20 and 1.40 MJ/ha, respectively were estimated while energy efficiency index were found to be 27, 47 and 20% for traditional, reduced-conventional and conventional tillage methods, respectively. The highest net monetary return and cost benefit ratio of ₦382,000.00k and 3.05 were estimated for reduced-conventional, ₦351, 600.00 k and 2.31 for conventional tillage, while the least values of ₦220, 000.00 k and 2.11 were recorded for traditional tillage method. The result revealed that reduced-conventional tillage was better than both traditional and conventional tillage methods in terms of energy productivity, net energy gain and energy efficiency index. Economically, production of fluted pumpkin under reduced-conventional tillage shows the highest net monetary return and cost benefit ratio compared to the other two tillage methods considered.

Three-Dimensional Characterization of Dry Particle Coating Structures Originating from the Mechano-fusion Process.

Dry particle coating processes are of key importance for creating functionalized materials. By a change in surface structure, initiated during coating, a surface property change and thus functionalization can be achieved. This study introduces an innovative approach employing 3D X-ray micro-computed tomography (micro-CT) to characterize coated particles, consisting of spherical alumina particles (d50 = 45.64 μm), called hosts, surrounded by spherical polystyrene particles (d50 = 3.5 μm), called guests. The formed structures, hetero-aggregates, are generated by dry particle coating using mechano-fusion (MF). A deeper understanding of the influence of MF process parameters on the coating structures is a crucial step toward tailoring of coating structure, resulting surface property and functionalization. Therefore, the influence of rotational speed, process time, and total mechanical energy input during MF is explored. Leveraging micro-CT data, acquired of coated particles, enables non-stereologically biased and quantitative coating structure analysis. The guest's coating thickness is analyzed using the maximum inscribed sphere and ray method, two different local thickness measurement approaches. Particle-discrete information of the coating structure are available after a proper image processing workflow is implemented. Coating efficiency and guest's neighboring relations (nearest neighbor distance and number of neighbors inside search radius) are evaluated.

Enhancing the Thermal and Energy Performance of Clay Bricks with Recycled Cultivated Pleurotus florida Waste

The development of energy-efficient and sustainable building materials is imperative to reduce energy consumption in the construction sector. This study addresses both the applied problem of increased solar heat gain and decreased indoor thermal comfort, as well as the scientific problem of reducing the thermal conductivity of clay bricks. It investigates the incorporation of recycled spent mushroom materials, consisting of Pleurotus florida mycelia and rice husk waste, as a novel additive in the production of fired clay bricks (FCBs) to enhance thermal insulation properties. The developed bricks were utilized in an optimized wall design for a residential building in New Cairo, Egypt. The wall design is created using energy modeling software, including Honeybee, Ladybug, Climate Studio, and Galapagos. The results demonstrate that an optimal waste content of 15% and a firing temperature of 900 °C yield the best thermal performance. Compared to traditional FCB walls, the new design incorporating the florida waste additive significantly improves thermal comfort, as indicated by a lower predicted mean vote and predicted percentage of dissatisfaction. Furthermore, the developed walls contribute to a reduction in CO2 emissions of 6% and a decrease in total energy consumption of 38.8%. The incorporation of recycled florida waste offers a sustainable approach to enhancing standard brick fabrication processes. This work highlights the promise of agricultural waste valuation for the development of eco-friendly and energy-efficient building materials. Future research should explore the mechanical strength, acoustics, cost–benefit analysis, and field implementation of the developed walls, thereby addressing both the scientific and applied aspects of the problem.

The Effective Fragment Molecular Orbital Method: Achieving High Scalability and Accuracy for Large Systems.

The effective fragment molecular orbital (EFMO) method has been developed to predict the total energy of a very large molecular system accurately (with respect to the underlying quantum mechanical method) and efficiently by taking advantage of the locality of strong chemical interactions and employing a two-level hierarchical parallelism. The accuracy of the EFMO method is partly attributed to the accurate and robust intermolecular interaction prediction between distant fragments, in particular, the many-body polarization and dispersion effects, which require the generation of static and dynamic polarizability tensors by solving the coupled perturbed Hartree-Fock (CPHF) and time-dependent HF (TDHF) equations, respectively. Solving the CPHF and TDHF equations is the main EFMO computational bottleneck due to the inefficient (serial) and I/O-intensive implementation of the CPHF and TDHF solvers. In this work, the efficiency and scalability of the EFMO method are significantly improved with a new CPU memory-based implementation for solving the CPHF and TDHF equations that are parallelized by either message passing interface (MPI) or hybrid MPI/OpenMP. The accuracy of the EFMO method is demonstrated for both covalently bonded systems and noncovalently bound molecular clusters by systematically examining the effects of basis sets and a key distance-related cutoff parameter, Rcut. Rcut determines whether a fragment pair (dimer) is treated by the chosen ab initio method or calculated using the effective fragment potential (EFP) method (separated dimers). Decreasing the value of Rcut increases the number of separated (EFP) dimers, thereby decreasing the computational effort. It is demonstrated that excellent accuracy (<1 kcal/mol error per fragment) can be achieved when using a sufficiently large basis set with diffuse functions coupled with a small Rcut value. With the new parallel implementation, the total EFMO wall time is substantially reduced, especially with a high number of MPI ranks. Given a sufficient workload, nearly ideal strong scaling is achieved for the CPHF and TDHF parts of the calculation. For the first time, EFMO calculations with the inclusion of long-range polarization and dispersion interactions on a hydrated mesoporous silica nanoparticle with explicit water solvent molecules (more than 15k atoms) are achieved on a massively parallel supercomputer using nearly 1000 physical nodes. In addition, EFMO calculations on the carbinolamine formation step of an amine-catalyzed aldol reaction at the nanoscale with explicit solvent effects are presented.

Cold-water coral energy reserves and calcification in contrasting fjord environments

The relationship between energy reserves of cold-water corals (CWCs) and their physiological performance remains largely unknown. In addition, it is poorly understood how the energy allocation to different metabolic processes might change with projected decreasing food supply to the deep sea in the future. This study explores the temporal and spatial variations of total energy reserves (proteins, carbohydrates and lipids) of the CWC Desmophyllum dianthus and their correlation with its calcification rate. We took advantage of distinct horizontal and vertical physico-chemical gradients in Comau Fjord (Chile) and examined the changes in energy reserves over one year in an in situ reciprocal transplantation experiment (20 m vs. 300 m and fjord head vs. mouth). Total energy reserves correlated positively with calcification rates. The fast-growing deep corals had higher and less variable energy reserves, while the slower-growing shallow corals showed pronounced seasonal changes in energy reserves. Novel deep corals (transplanted from shallow) were able to quickly increase both their calcification rates and energy reserves to similar levels as native deep corals. Our study shows the importance of energy reserves in sustaining CWC growth in spite of aragonite undersaturated conditions (deep corals) in the present, and potentially also future ocean.

Research on energy-saving control of agricultural hybrid tractors integrating working condition prediction.

To address the issues of tractors using too much fuel and not being energy efficient, a predictive control strategy based on Pontryagin's minimum principle integrating working condition prediction is proposed for agricultural hybrid tractors. The Dongfanghong 1804 tractor is being used for research. Firstly, the main parameters of the hybrid drive system are determined and modeled. Secondly, based on the adaptive cubic exponential forecasting method, the working condition information for a period of time in the future is predicted through historical working condition information. Furthermore, combining the predicted working conditions information, the goal is to minimize the total energy consumption cost of the entire machine. Motor power and diesel engine power are control variables. The battery state of charge is a state variable. Subsequently, a predictive control strategy based on Pontryagin's minimum principle integrating working condition prediction is proposed. Finally, the simulation test is carried out based on the MATLAB simulation platform. Research indicates: under plowing conditions, compared with the power following control strategy, the proposed predictive control strategy can effectively manage the performance of the diesel engine and motor, ensuring they operate at their most efficient level. The total energy consumption costs of the power following control and predictive control strategies are 37.17 China Yuan (CNY) and 33.67 CNY, respectively. The cost of energy used is decreased by 9. 42%, which helps make tractor field plowing more efficient and economical.