Energy Parameters Research Articles

Digital Twin in the Design and Dynamic Assessment of Energy Performance of Multi-Family Buildings

The article explores the potential of Digital Twin (DT) technology in the design and dynamic assessment of the energy performance of multi-family buildings. Traditional approaches to building energy assessment provide static data that do not account for changing operational conditions and lack continuous energy consumption-monitoring capabilities. The use of Digital Twin enables monitoring and analyzing of the building’s energy parameters at every stage of its life cycle. The article presents the application of DT technology for assessing energy performance at the conceptual stage and in the early phases of design. These parameters must meet legal requirements. Validation conducted on four multi-family buildings demonstrated high accuracy, with the average difference between predicted and actual energy performance (EP) values below 3.5%. Thanks to the DT model, it is possible to determine energy parameters already at the conceptual stage, which helps avoid costly changes in later project phases. Early determination of these parameters also allows for accurate estimation of design and investment costs. Tests of the proposed solution were conducted on several multi-family buildings, comparing preliminary data with final results. The research results show that DT technology allows for precise planning of energy performance at the conceptual and preliminary design stages. This reduces operational costs, increases energy efficiency, and better adapts buildings to changing technological and legal conditions.

Assessment of the Effects of Intake Temperature and Injector Structure on the Combustion Characteristics of Direct‐Injection Spark‐Ignition Methanol Engines

In this article, to address the issues of slower droplet evaporation and fuel mixing inhomogeneity caused by the high latent heat of vaporization of methanol, the effects of the number of nozzle holes and spray cone angle (θsca) on the combustion characteristics of a direct‐injection spark‐ignition methanol engine are numerically investigated at different intake temperatures (Tint) under constant injection pressures. In the results, it is indicated that the maximum‐indicated thermal efficiency (ITE) is 48.01% at 8 holes and a Tint of 328 K. Although the ITE at 298 K with 8 holes is 1.42% lower than 328 K, NOx emissions and ringing intensity (RI) are reduced by 90.46% and 90.61%, respectively. Simultaneously, emissions of CO, hydrocarbon (HC), Soot, unburned methanol, and formaldehyde remain at a low level. Second, there exists an optimal θsca at different holes, thus obtaining the best fuel economy and emissions. The maximum ITE is 48.1% at 8 holes and a θsca of 26°. Finally, under the same energy input and parameter, compared with the diesel engine of the optimal start of injection, the ITE of the optimized methanol engine is increased by 1.65%, and the RI, NOx, HC, CO, and Soot emissions are reduced by 98.58%, 77.85%, 99.35%, 85.71%, and 78.38%, respectively.

Methane Adsorption Energy Variation Affected by Industrial Components in Deep and Thick Coal Reservoirs

The relevant literature indicates that coal facies have a significant impact on the pore structure and adsorption properties of deep coal reservoirs. The content of submicroscopic components is used to calculate the parameters of coal facies. Based on traditional coal phase parameters and ash content, the coal phases of the coal samples in the study area were divided. Based on the adsorption potential theory, the differences in methane adsorption energy changes between different coal phases were compared. The results are as follows. The wet herbaceous swamp facies (type A) could be divided into two subtypes by using the ash yield: subtype A-1 (with an ash yield lower than 20% and a gel index (GI) lower than 5), and subtype A-2 (with an ash yield larger than 20% and a GI lower than 5). With the increase in micro-pore volume shown in A-1 samples, cumulative surface free energy increases linearly and the maximum rate of decline decreases linearly. Coal facies have an important effect on adsorption parameters: VL increases and PL decreases with higher structural preservation index (TPI). The effect of a low ash yield and different Ro,max on methane adsorption energy parameters is stronger.

A $C^\ast$-algebraic view on the interaction of real- and reciprocal space topology in skyrmion crystals

Understanding the interaction of real- and reciprocal space topology in skyrmion crystals is an open problem. We approach it from the viewpoint of C^\astC*-algebras and calculate all admissible Chern numbers of a strongly coupled tight-binding skyrmion system on a triangular lattice as a function of Fermi energy and texture parameters. Our analysis reveals the topological complexity of electronic states coupled to spin textures, and the failure of the adiabatic picture to account for it in terms of emergent electromagnetism. On the contrary, we explain the discontinuous jumps in the real-space winding number in terms of collective evolution in real-, reciprocal, and mixed space Chern numbers. Our work sets the stage for further research on topological dynamics in complex dynamic spin textures coupled to external fields.

Deciphering the nonlinear and synergistic role of building energy variables in shaping carbon emissions: A LightGBM- SHAP framework in office buildings

As the global demand for sustainable buildings continues to rise, accurately assessing and managing carbon emissions during the operational phase of buildings has become an urgent challenge. This study employs machine learning and Explainable Artificial Intelligence (XAI) to explore the impact and synergistic effects of energy variables on carbon emissions in office building operations. Initially, energy consumption data from 28 office buildings in China were collected to construct a dataset comprising 24 energy indicators across four dimensions. The Lightweight Gradient Boosting Machine (LightGBM) and Extreme Gradient Boosting (XGBoost) models were used to predict building carbon emission, PV carbon offset, and net carbon emission based on different energy parameters. The SHapley Additive exPlanations (SHAP) method was utilized to interpret the model results from both global and local perspectives. The study results indicate that: (1) The LightGBM model, optimized with GridSearchCV, shows better stability and reliability in predicting carbon emissions. (2) SHAP bar plots和SHAP beeswarm plots reveal that the WWR in the ES dimension and the PVArea in the EP dimension are the most critical variables affecting building carbon emission and PV carbon offset. (3) SHAP dependence plots show that the contributions of energy variables are not independent, with differentiated synergistic effects among variables in emission reduction. (4) SHAP force plots consider interactions among multiple variables, identifying key variable ranges to minimize building carbon emission and maximize PV carbon offset.

A method for estimating maximum safe installable power for groundwater extraction with application to Africa

New groundwater development is a likely way to meet growing global water demand but needs careful management. To help inform the sustainable development of groundwater resources, a novel method based on the maximum safe installable power for water pumping systems and the maximum safe remaining installable power (considering current abstraction) is developed. The proposed model couples energy, technology and hydrogeological parameters, and is then developed to compute the maximum power that can be safely installed per km2 without exceeding a maximum annual pumpable volume, calculated through available recharge and storage. The model is applied to estimate the maximum safe installable power across Africa with a 0.2-degree resolution, using available energy and hydrogeological data. Constrained by recharge (considering that 25 % of the annual recharge is available for utilization), the maximum safe installable power ranges between 0 and 9960 W/km2 across Africa with regions such as the Congo Basin (~340 W/km2), and western Africa between the Ivory Coast and Nigeria (~230 W/km2) identified as having high potential for sustainable pumping system development. Constrained by storage (considering that 0.1 % of storage can be withdrawn per year), it ranges between 0 and 13,425 W/km2 highlighting the ability to harness storage for pumping system development in the large aquifers of Northern Sahara (~8720 W/km2). When considering limitations posed by both groundwater recharge and aquifer storage (considering that 25 % of the annual recharge and 0.1 % of storage can be withdrawn per year), along with current groundwater withdrawal, 93 % of the maximum safe installable power remains still installable on average across Africa. Nevertheless, 2 % of the locations are estimated to be already experiencing overexploitation, particularly in Sudan, northern Africa, and northeastern South Africa. These findings provide a novel and adaptable way to examine water security, which can assist institutions in targeting investments to meet water demand sustainably.

Exploration of Arrhenius activation energy and thermal radiation on MHD double-diffusive convection of ternary hybrid nanofluid flow over a vertical annulus with discrete heating

The primary objective of this article is to examine the effect of discrete heating on MHD double-diffusive convection and thermal radiation of ternary hybrid nanofluid flow heat and mass transfer in a vertical cylindrical annulus along with Arrhenius activation energy and chemical reaction. In this study, the cavity inner wall has two distinct flush-mounted heat sources, while the outer wall is isothermally cooled at a lower temperature. The top and bottom walls are thermally insulated. The ensuing equations that govern the physical framework are solved using the implicit Crank-Nicholson finite difference technique. As the heater advances upward, the flow intensity decreases, leaving a part of the fluid static at the bottom of the cylinder. Because more heat induces high buoyant flow in the annulus, the absolute value of axial velocity and wall temperature rises as the length of the heat source rises. Enhancing the activation energy parameter values drops the Arrhenius energy function, elevating the pace of the generative chemical process and hence the concentration. Increasing the thermal radiation parameter lowers the surface heat flux while enhancing the nanofluid temperature. The Brownian motion parameter corresponds to the random motion of nanoparticles in a fluid, and this irregular movement augments the collision of nanoparticles with fluid particles, causing the particle's kinetic energy which leads to thermal energy and hence increases temperature, a 10% increment in Brownian motion parameter leads to 26% rise in the temperature. Also, the heat and mass transfer characteristics are forecasted and analyzed by considering the Levenberg–Marquardt backpropagating artificial neural network technique.

Single Phase Induction Motor Electrical Performances

Abstract A single-phase induction motor (SPIM) is one of the most widely used types of electric motors for applications that require small to medium power even his features don’t look very efficient energy parameters point of view. This motor runs on single-phase AC power, a real advantage for residential and light industrial applications and coupled with a DC permanent machine can emphasize its behavior in some specific situations. Starting and running performance of single-phase induction motor depend on running torque requirements of the load. Some statements about power factor and efficiency will be done, also.

Cutting-edge Bioinformatics strategies for synthesizing Cyclotriazadisulfonamide (CADA) analogs in next-Generation HIV therapies

Cyclotriazadisulfonamide (CADA) is a macrocyclic compound known for its unique mechanism in inhibiting HIV infection by downregulating the CD4 T-cell receptor, a crucial entry point for the virus. Unlike other antiretrovirals, CADA exhibits activity against a wide range of HIV strains, as all HIV variants require CD4 binding for infection. Furthermore, CADA has shown a synergistic effect with clinically approved anti-HIV drugs, offering potential for enhanced therapeutic strategies (Vermeire & Schols, [65]). One proposed mechanism for CADA’s inhibition of the CD4 receptor involves blocking the gates of the Sec61 channel, thereby preventing its translocation. However, CADA suffers from poor solubility and bioavailability. To address this, the study aimed to design CADA analogs with improved binding to the Sec61 channel, enhanced bioavailability, and reduced toxicity. The analogs were designed using SeeSAR, with Avogadro and Meeko used for 3D configuration and pseudoatom placement, respectively. AutoDock Vina version 1.2.4 was employed to predict the binding energies of these analogs. Of the 113 analogs designed, 93 demonstrated a more negative binding energy to the Sec61 channel compared to CADA. Structure-binding energy analyses were done to the top-binding analogs to show favorable structural modifications. Enzyme-ligand interactions were analyzed to elucidate the forces contributing to these binding energies. Additionally, 33 of the 113 analogs were deemed bioavailable using a bioavailability criteria specific for macrocycles. Toxicity predictions using PASS Online and StopTox identified analogs JGL023, JGL024, JGL032, and JGL047 as potential drug candidates. Molecular dynamics simulations using Gromacs-2020.4 revealed that JGL023 and JGL032 exhibited the most favorable binding to the Sec61 channel, as determined by evaluating ligand and residue flexibility, compactness, contact frequency, motion pathways, free energy, and other relevant parameters. Synthetic routes for these four analogs were proposed for future studies. The results of this study offer a new perspective on developing drugs to inhibit HIV entry.

Optical materials enhancing the chemical reactivity characteristics of N-benzyloxycarbonyl-L-phenylalanine: Spectroscopic, electronic properties, natural bond orbital, stability, electron-hole, Topology and molecular docking analyses

In the field of organic chemistry, the exploration of heterocyclic compounds is considered as vital, with roots in medicinal chemistry and the synthesis of organic composites. The optimized structural configuration with the geometrical values was obtained and related to the experimental data. The theoretical computational methods were carried out using a versatile basis set, B3LYP/6–311++G(d,p). The spectroscopic insights of N-Benzyloxycarbonyl-l-Phenylalanine (NBCLP) were performed, and the simulated assigned vibrational wavenumbers (PED contributions) were compared with the experimental information. Further, employing the optimized structure of FMO's molecular orbitals, energy parameters were attained for the various solvents. The detailed theoretical interpretations were assessed on the UV–Vis absorption spectra (TD-DFT/M062X) for different solvents, and their respective values were related to the experimental value. The electronic properties of the FMO's orbitals match the experimental UV–Vis absorption energy value. The reactivity regions (nucleophilic and electrophilic) were obtained using the MEP map, and the corresponding lone pair/donor-acceptor transitions along with the higher stabilization energies were discussed using NBO analysis. Moreover, using the Multiwave function analyzer interface, electron-hole analysis for the excited states, along with parameters such as excitation energy, charge transfer length, H, t, and Δr indices for the above-mentioned solvents, and topological analysis, viz., ELF, LOL, and RDG, were discussed for the header composite. To enhance the biological behavior, molecular docking-in silico analysis was accomplished, suitable protein receptors were attained, and the results show the measure of binding energy in the ligand-protein interactions. Consequently, the present investigations imply that NBCLP may be designated as a potent and satisfying medication for the ailment of tuberculosis.

The Effect of Assist Gas Type on Nitinol Microsecond Laser Cut Edges: A Study on the Use of Oxygen, Argon, Nitrogen, Helium, and Compressed Air

Abstract Historically, the published literature for laser cutting atomically balanced nickel-titanium alloy (Nitinol) tubular devices assumes slow cut rates with an inert argon assist gas. Herein, a novel application of an exothermic reactive oxygen assist gas was employed during Nitinol laser micromachining, which enabled a 38.1 mm/s cut rate, a 4.5-times improvement from traditional argon cutting. Furthermore, this led to the realization of improved cut quality: 2-times less dross, a 2-times lower surface roughness, and a minimal heat-affected zone. Of the tested assist gases (oxygen, argon, nitrogen, helium, and compressed air), oxygen was found to provide the best cut quality, achieving dross-free cuts. Additionally, oxygen was shown to produce a relatively low arithmetic mean average surface roughness of 0.48 μm, when compared to argon at 0.85 μm. A decrease in surface roughness was found to be associated with an increase in cut rate. These findings suggest that assist gas melt flow dynamics has a higher contributing factor than laser pulse energy parameters. In-situ thermographic monitoring of the melt flow during processing demonstrated a clear difference in the melt flow pattern between a reactive oxygen assist gas and inert argon assist gas. Furthermore, with the culmination of nanoindentation analysis and microstructural characterization, it was concluded that long-pulse laser micromachining can produce cuts with negligible microstructural alterations to the bulk material. This study quantitatively demonstrates the benefits observed during laser cutting Nitinol with a reactive oxygen assist gas when compared to previous studies that employ an inert argon assist gas.

Co-pyrolysis behaviors, kinetics, and thermodynamics of sludge, lignite and biomass through fixed-bed reactor experiments and thermogravimetric analysis

Co-pyrolysis behaviors, kinetics, and thermodynamic parameters of petrochemical sludge (PS), lignite (HL), and pine wood (PW) were investigated via fixed-bed reactor experiments and thermogravimetric analysis. Fixed-bed experiments showed H2 and CO2 were main gases from PS, HL, and blends, CO from PW and PS, and CO and CH4 from PS and HL. Thermal analysis indicated that ternary blends’ de-volatilization had two parts dominated by PW and HL, respectively. The comprehensive de-volatilization index increased from 7.0 × 10-7 to 3.3 × 10-6 %2/(min2·°C3) as PW ratio rose from 20 % to 40 %. Effects of heating rates on pyrolysis properties, kinetics, and thermodynamics were studied using thermal analysis data. Characteristic indices increased, and activation energies decreased with HL or PW mixing; minimum activation energy was 147.2 kJ/mol for PS and HL blend. Blending lignite and biomass improved pyrolysis indices of petrochemical sludge and reduced activation energy and thermodynamic parameters, benefiting sludge disposal.

Analyzing lump-type solutions in scalar field models through configurational information measure

In this paper we employ a configurational information measure, specifically the differential configurational complexity (DCC), to quantify the information content of lump-type solutions in various scalar field models, including two modified inverted ϕ4 models, the modified ϕ3 model, as well as two additional families of lump models. Our objective is to complement previous studies by providing an informational perspective that distinguishes different solutions based on their energy configurations. We explore how the DCC measure relates to energy and its applicability in analyzing degenerate states. Our findings indicate that DCC effectively correlates with the energy parameters of the solutions, offering significant insights into their informational properties. This study underscores the value of using informational metrics like DCC to deepen our understanding of the structural and dynamic characteristics of complex systems in theoretical physics.

Theoretical models from experiments on particle population in convective arrays

Studying suspensions of gold nanorods has provided valuable knowledge on variations in concentration and how nanoparticles behave. Analysis of UV–visible spectra has shown changes in both longitudinal and transverse peaks, indicating a reduction in nanoparticle absorption peaks as the nanoparticle concentration decreases in suspension. Furthermore, changes in droplet contact angles have elucidated a direct correlation between nanoparticle density and droplet dynamics, shedding light on the intricate interplay between concentration reduction and droplet behavior. Investigations into cetyltrimethylammonium bromide (CTAB-coated) gold nanorods have unraveled the complexities of depletion, electrostatic, and Van der Waals forces, offering valuable knowledge on the self-assembly mechanisms governing these nanomaterials. The examination of interactions within coffee stain rings has underscored the crucial role of nanoparticle density in nanostructure arrangements, influencing deposition patterns and contributing to a deeper understanding of volume fraction evolution in nanostructured systems. By establishing a quantitative framework for interpreting energy parameters and observing optimal fitting agreements with experimental data, this research provides a solid foundation for future endeavors aimed at elucidating nanomaterial behavior in suspended systems. This comprehensive overview lays the groundwork for tailored manipulation of gold nanorod properties, emphasizing the essential relationship between density and contact angle in shaping wetting phenomena and surface engineering practices.

To the selection of battery parameters for a M1 category hybrid vehicle

Background: To optimize the operation of a hybrid vehicle power plant, it is necessary to correctly select the parameters of its traction battery, which significantly affect the control algorithm and charge-discharge balance. The presence of a methodology that allows one to make a reasonable choice depending on the characteristics of the target vehicle, the conditions and modes of its operation will make it possible to increase energy efficiency indicators.Aims: The work aim was to develop a methodology for calculating the parameters of a hybrid vehicle traction battery using the energy charge-discharge balance of its power plant.Matherials and methods: A mathematical model of the charge-discharge energy balance has been proposed. Using this model, it is possible to make appropriate calculations on the amount of energy expended by the power plant when a vehicle moving through the stages of the European urban cycle, and analyze various algorithms for controlling it to achieve maximum energy efficiency, as well as select capacity and pover of traction battery. The basis for the calculations was the cycle described in UN Regulation No. 83.Results: The process of energy accumulation in a traction battery is considered, and criteria for choosing an algorithm for the operation of the vehicle’s power plant are indicated. The energy of vehicle movement in the urban cycle was determined, taking into account the operating time of the units, and the charge-discharge energy balance was calculated, which, in turn, made it possible to find the proper battery capacity. It has been established that the battery charge value at the end of the cycle should be equal to the initial value, which allows the use of a lower capacity battery and ensure maximum energy efficiency of the power plant. Also, based on the calculation results, recommendations were made regarding the optimization of the specific energy and weight-size parameters of the battery.Conclusions: The proposed methodology allows for a reasonable choice of а hybrid vehicle power plant parameters to ensure its energy efficiency.

Analysis of the Energy and Emission Performance of an Automatic Biomass Boiler in the Context of Efficient Heat Management

Analysis of the Energy and Emission Performance of an Automatic Biomass Boiler in the Context of Efficient Heat Management

Study on energy harvesting performance of a tidal current turbine based on three pitching circular motion hydrofoils using numerical method

If the pitching hydrofoil moves following a circular trajectory, the turbine can use multiple hydrofoils to capture energy from the current, which has the potential to improve efficiency. In this study, by solving Reynolds-averaged Navier-Stokes equation with Shear Stress Transport k-ω model, hydrodynamic performance of the new turbine with three hydrofoils was investigated. First, energy harvesting performance of the turbine with a wide range of motion parameters was studied. Then, based on the optimal operating condition, energy harvesting principle of the turbine was analyzed from the perspectives of vortex-body interactions, hydrodynamic forces and energy parameters. Finally, the fundamental reasons for the variation of efficiency with motion parameters were investigated. Results show that the maximum efficiency reaches about 50%, much higher than that of turbines of the same type with one hydrofoil and the vertical axis turbine. The turbine harvests energy mainly through the circular motion and the lift is the main driving force for the turbine to harvest energy. At the optimal motion parameters, the interactions between vortex and hydrofoil is favorable, which increases the positive work done by the lift and reduces the energy consumed by the horizontal force and pitch moment at specific moments, thereby improving the efficiency.

New Advances on the Dispersive and Polar Surface Properties of Poly(styrene-co-butadiene) Using Inverse Gas Chromatography.

The IGC surface technique led to the dispersive and polar properties of poly(styrene-co-butadiene) rubber (SBR) by adsorption of organic solvents at various temperatures. Our new methodology, based on the thermal Hamieh model and the London dispersion interaction energy, was used to determine the London dispersion surface energy, the polar acid-base surface energy, and the Lewis acid-base properties of the copolymer. The different surface energy parameters of the SBR were obtained as a function of temperature from the chromatographic measurements. The dispersive and polar free energies of adsorption of the various n-alkanes and polar molecules on poly(styrene-co-butadiene) were determined at different temperatures. A decrease in the London dispersive surface energy and the polar Lewis acid-base surface energies of SBR was highlighted when the temperature increased. It showed a Lewis amphoteric character of poly(styrene-co-butadiene) with a highest basic constant 10 times larger than its acidic constant. This new and original method can better characterize the surface thermodynamic properties of poly(styrene-co-butadiene).

Effects of radiation and activation energy on magnetized ternary nanofluid flow produced by a slippery elastic sheet with entropy analysis

This study looks into two-dimensional, incompressible magnetohydrodynamic flow of ternary hybrid nanofluid passing a stretched surface through a porous material taking into consideration activation energy, heat sink, chemical reaction parameter, and viscous dissipation. This study’s aim is to analyse the flow behaviour for temperature, concentration and velocity with entropy in the presence of titanium dioxide, aluminium oxide, and copper oxide nanoparticles. An effective similarity conversion procedure is used to transform partial differential equations to a nonlinear ordinary differential equations system. Employing proper boundary restrictions, the nonlinear equations are solved using the MATLAB bvp4c technique. A number of physical flow parameters including velocity, thermal and concentration profiles are investigated through tables and graphs in order to assess the flow behaviour. The main outcomes indicate that the velocity profile was decreased by the magnetic parameter and porosity parameter. Also, the Brinkmann number rises the entropy generation rate, while radiation and Brinkmann number decrease the Bejan number. The Sherwood number falls with larger activation energy and magnetic parameter, while it improves with increased Schmidt number, radiation parameter and chemical reaction parameter.

Non-Isothermal Crystallization Kinetics and Properties of CaO-Al2O3-SiO2 (CAS) Glass-Ceramics from Eggshell Waste, Zeolite, and Pumice.

In this study, the crystallization behavior, microstructure, and mechanical and physical properties of CaO-Al2O3-SiO2 (CAS)-based glass-ceramics prepared from eggshell waste, zeolite, and pumice were investigated using X-ray diffraction (XRD), differential thermal analysis (DTA), scanning electron microscopy (SEM), a nanoindentation tester, and the Archimedes method. XRD analysis revealed that anorthite and wollastonite crystalline phases precipitated in the glass-ceramic samples after sintering at temperatures of 1000 °C and 1100 °C. However, diffraction peaks belonging to the wollastonite phase disappeared after sintering at 1200 °C, while peaks representing the pseudowollastonite phase were detected together with anorthite in the samples. SEM images showed that the crystals become coarser as the sintering temperature increased, with the crystal morphology transitioning from needle-like to rod-like. The crystallization activation energy (Ea) and Avrami parameter (n), both kinetic parameters, were calculated from DTA curves plotted at different heating rates using the Kissinger, Ozawa, and Matusita approaches. The results indicated that the crystallization activation energy of the CASZ glass ranged from 406 to 428 kJ mol-1, while that of the CASP glass varied from 356 to 378 kJ mol-1, depending on the method used. Additionally, the Avrami constant (n) was calculated to be 3.33 for CASZ and 2.89 for CASP. The hardness and bulk density of the glass-ceramic samples were significantly affected by the porosity present in the structure, with the highest hardness and bulk density values achieved for the CASZ glass-ceramic sample at the initial sintering temperature of 1000 °C.