Positive Energy Research Articles

Experimental and numerical approach for the evaluation of PV-system performance on energy and environmental behavior of nearly zero energy buildings: Case study in Mediterranean climate

Nowadays, the performance of photovoltaic (PV) systems has strategic role for satisfying the standard of net or nearly zero energy building with in-situ production. In this frame, the novelty of the paper is the proposal of a combined experimental and numerical approach for evaluating the mismatch between PV production and consumptions during design, operational and future performance under expected emissions scenarios. First of all, it proposes a comparison of production estimation by means of several tools for the evaluation of the energy balance in the design phase; then the expected and real behavior is compared with also the evaluation of the performance ratio (PR) evolution as function of cell temperature. Finally, a sensitivity analysis is proposed in the short and medium scenarios by varying the size of installed system and considering the degradation rate under future weather conditions. The approach is applied to a case study in a typical Mediterranean climate, starting from the monitoring data available for the building energy request and the renewable production (2016–2022). The results of the case study indicate that the PR greatly influences the performance, mainly under expected climate changes, since the operational emissions could increase of more than 15 % compared to actual performance also if the zero energy balance is satisfied. Furthermore, through a sensitivity analysis on the PV-system size, the study demonstrates that with a maximum linear degradation rate of 1.51 %/year, the building could be configured as nearly zero energy in the medium term (20 years) also with lower peak power. The analysis also suggests that the maximization of installed power is a prerequisite to follow the implementation of positive energy goal because, under all considered climatic evolutions it can balance the penalties both due to technical aspects that to modification of consumption and production profiles.

Design and experimental investigation of a positive feedback magnetic-coupled piezoelectric energy harvester

A positive feedback magnetic-coupled piezoelectric energy harvester (PFM) is proposed to address the limitations of current piezoelectric energy collectors, including restricted acquisition direction, limited acquisition bandwidth, and low energy output. Firstly, the dynamic theoretical model of the energy harvester was established, and the optimization factors were explored, providing a solid theoretical foundation for subsequent research endeavors. The energy capture characteristics of rectangular beam and compound trapezoidal beam were compared through finite element simulation analysis. Subsequently, an experimental platform was constructed and an optimized experimental methodology was devised to analyze the energy capture characteristics and enhance the performance of the energy harvester. The results demonstrate that the positive feedback magnetic-coupled PFM with a trapezoidal beam exhibits superior energy capture efficiency. Furthermore, it is observed that the optimized energy harvester possesses wide frequency coverage, multi-directional capabilities, low-frequency adaptability, and facilitates easy vibration. When the 45 kΩ resistor is connected in series and subjected to a longitudinal external excitation amplitude of 0.5 g, it is capable of generating an average voltage and power output of 4.20 V and 0.39 mW respectively at a vibration frequency of 9 Hz. Similarly, when exposed to a transverse external excitation amplitude of 1 g, it can produce an average voltage output of 6.2 V and power output of 0.85 mW at a vibration frequency of 19 Hz. When the inclination angle of the energy harvester is set to 35 degrees, the maximum voltage output occurs at a frequency of 18 Hz and the Z-axis to X-axis force ratio of the energy harvester is 1.428. These research findings can serve as valuable references for piezoelectric energy harvesting applications in self-powered microelectronic systems.

Application of passive and active scenarios to a residential building in a dry and hot climate to achieve a positive energy building (PEB)

Designing a nearly zero energy building (NZEB) and more exclusively a positive energy building (PEB) hold significant importance these days. Achieving this objective requires an effective blend of renewable systems and the energy efficient envelope. This study focuses on a villa situated in the southeast of Kerman, Iran with hot and dry summers. Commencing with the current energy-efficient design of the structure, the research conducted various analyses to explore the impacts of different strategies or alternative approaches that contribute to achieving a NZEB or PEB. The parameters examined in the analysis that pertain to the building envelope, encompass insulation scenarios, window-to-wall ratio, and glass types as passive strategies, along with the integration of wind turbine energy production as an active energy solution. The findings indicate that, under hot and dry conditions in this region, the optimal passive strategies for the case study involve a 40 % window-to-wall ratio, polyurethane insulation, and triple-layered glass with argon. This combination results in a noteworthy reduction in total annual energy consumption, decreasing from 24,344.56 kWh to 11,909.64 kWh. To offset the remaining energy requirements and transform the building into a positive energy structure, a wind turbine was employed. This integrated approach not only aligns with the specific climatic conditions of the area but also demonstrates the feasibility of achieving a positive energy building which resulted in a surplus energy of 1,414.13 kWh.

Design of GRETA Cooling Systems

The Gamma-Ray Energy Tracking Array (GRETA) is a full 4π gamma-ray tracking detector capable of reconstructing the energy and three-dimensional position of gamma-ray interactions within a compact sphere of high-purity germanium crystals. The GRETA Detector Array Sphere will have the capacity to accommodate a total of 30 Germanium Quad Detector Modules (QDM). The 30 QDMs are to be cooled and maintained below 100 K using liquid nitrogen (LN) at all times while the array is in normal operation, and will require regular filling of a LN Dewar on each module. The Dewar is designed to allow the Quad Module to be operated in any orientation with a LN holding time of no less than 12 hours when the detector module is fully powered. An automated LN cooling and refilling system is required to supply LN to the 30 QDMs and ensure them maintained below 100 K. Each of the GRETA QDMs houses a total of 148 pre-amplifier units within the module, and with the high power consumption of each pre-amplifier, active cooling of the pre-amplifier compartment is required. Additionally, each Quad Module will have 4 digitizer modules attached to it, which generate heat and require cooling as well. A closed-loop liquid (Glycol) cooling system will provide the required temperature stability and dissipate power generated heat for electronics. This paper presents design of the GRETA LN cooling system for detectors and the closed-loop liquid cooling system for electronics including technical requirements, design schemes, key components, operation modes, and so on.

Comprehensive Bicubic Formalism of Ordinary and Novel (dm) Particles With Substituted Virtual Novel Electron Describing the Bohr Atom

The particle limiting velocity solutions from the bicubic limiting velocity equation ( Soln, J., 2021.1.2, 2022) have been very useful in carrying out parallel studies of ordinary and novel particles. This study is facilitated with the help of evolutionary congruent parameters, ordinaryz1 ⪯ 1, novel z2 = 1/z1 ⪰ 1 and congruent phase-angle α ⪯ π/2. At smooth matching point z1 = z2 = 1 and α = π/2, there is no physical difference between an ordinary and novel particle as they have the same limiting velocities. At α = π/3 ≺ π/2, they have already different limiting velocities with different other physical characteristics. Ordinary photon γ and novel doubly photon γN are indistinguishable at α = π/2, while at α = π/3 ≺ π/2, they are already physically different. That applies to any other particle, ordinary proton p versus novel proton pN, etc. Through trial and error, one finds that c3 the ordinary particle limiting velocity solution has ratio value of 1 at the comprehensive congruent phase-angle αO = π/5.1 = 0.616 which an ordinary particle of velocity v can satisfy at v ≃ c3, in fact, defining the value of c3. The quantum jump from the ordinary particle comprehensive congruent phase-angle αO to the novel particle comprehensive congruent phase-angle αN = 2αO = 2π/5.1 = 1.232 yields novel particle limiting velocity solution doubly Rc1,3 with ratio value of 1 which a novel particle velocity vN can satisfy with doublyRc1,3 ≃ vN, simply defining the value of doubly Rc1,3. This comprehensive quantum jump with fixed comprehensive congruent phase-angles αO and αN apply to any free and interacting ordinary particle (γ, e, ν,etc.) when connecting to the corresponding free and interacting novel particle (γN, eN, νN, etc.). Concerning the Bohr’s atom, we wish to address the question of negative energy electron e emitting positive energy radiation. To this end we simply substitute e with the virtual novel electron eN with the same radius r and velocity v. This virtual eN, due to the Coulomb potential energy V from the sitting proton p plus the centrifugal force, with the quantized orbital virtual novel electron angular momentum yields the positive virtual novel electron energy in the bicubic formalism. The frequencies of emitted radiation from virtual novel electron is practically the same as from the negative energy electron e.

Health Care Functions of Elderly Families with Hypertension Who Live Alone Life in Bandung District (Phenomenological Study)

Aims: The aim of this research is to explore the health care function of families of elderly people with hypertension who live their lives alone in Bandung Regency. Methods : This research design uses a qualitative method with an exploratory phenomenological approach. The number of participants was 7 people who conducted a focus group discussion (FGD). Results : The results of this research obtained 5 themes, namely recognizing internal and external health problems based on reflex response, making decisions based on personal needs and complaints of the elderly, caring for oneself by preventing and strengthening positive energy, maintaining environmental health through dividing tasks and joint financial responsibility, and increasing optimization utilization of health services. Conclusions : Research on elderly hypertension families reveals five main themes: understanding hypertension through psychological and physical responses, making decisions based on personal needs, self-prevention and positive energy, dividing environmental health and joint financial responsibility, and optimizing health facility use through PKM and Health Services.

“文化润疆”视域下的新疆中小学音乐课程思政教学探索

Xinjiang is a region where many ethnic groups live together, and the ideological and political education plays a prominent role in primary and secondary schools. In the context of “Nourishing the Cultures of Xinjiang”, this study explores use the multi-ethnic music resources and music education as a medium to seek to maximize the impact of music teaching on the ideological and political development of primary and secondary school students in Xinjiang. The aim is to form correct values, promote positive social energy, foster ethnic unity, and enhance cultural confidence.

EXTERNAL FACTORS OF RUSSIAN ENERGY SECTOR DEVELOPMENT: OPPORTUNITIES AND RISKS IN THE NEW GEO-ECONOMIC REALITY

The paper analyzes the main stages of the Russian energy sector development in the context of the influence of external factors. The author considers the role of the new export pipelines construction in strengthening the country’s position in global energy markets. The article provides an assessment of the dependence of Russian energy sector on foreign capital and technology. The author provides some practical recommendations for the development of the Russian energy sector in the context of Western sanctions and the transition to a low-carbon economy.

Acoustic shock wave induced chemical reactions–A case study of NaCl single crystal

Herein, we report the catalytic-free acoustic shock wave-induced synthesis of the non-stoichiometry compound of sodium chloride (Na3Cl2-P4/m) from the stoichiometry NaCl (B1). The shocked NaCl crystal structure is formed as a mixed phase together with the NaCl (B1) and (Na3Cl2-P4/m) thereby the formation of non-stoichiometry compound of Na3Cl2 is confirmed by the diffraction, vibrational, spectroscopic and microscopic techniques. X-ray photoelectron spectroscopic study reveals the positive energy shift of Na 1 s peak which confirms the formation of higher coordination number Na3Cl2 (six to eight) such that it can be considered as Na rich structure. The typical cubic morphology has changed into butterfly wing structure under shocked conditions which is found to be novel, to date. Due to the formation of Na-rich crystal structure, the electrical properties of the shocked crystal are greatly altered. The maximum values of the real part of the impedance of the control and shocked crystals are 1.9 × 107 ohm and 1.0 × 107 ohm, respectively at the lower frequency regions. The present study offers a new platform to synthesize the stable non-stoichiometry NaCl structures under ambient conditions by low pressure acoustic shock waves which could bring about new understanding and implications on NaCl crystals and their applications.

High Energy Solutions for p-Kirchhoff Elliptic Problems with Hardy–Littlewood–Sobolev Nonlinearity

This article deals with the study of the following Kirchhoff–Choquard problem: M∫RN|∇u|p(-Δp)u+V(x)|u|p-2u=∫RNF(u)(y)|x-y|μdyf(u),inRN,u>0,inRN,\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\begin{aligned} \\begin{array}{cc} \\displaystyle M\\left( \\, \\int \\limits _{{\\mathbb {R}}^N}|\ abla u|^p\\right) (-\\Delta _p) u + V(x)|u|^{p-2}u = \\left( \\, \\int \\limits _{{\\mathbb {R}}^N}\\frac{F(u)(y)}{|x-y|^{\\mu }}\\,dy \\right) f(u), \\;\\;\ ext {in} \\; {\\mathbb {R}}^N,\\\\ u > 0, \\;\\; \ ext {in} \\; {\\mathbb {R}}^N, \\end{array} \\end{aligned}$$\\end{document}where M models Kirchhoff-type nonlinear term of the form M(t)=a+btθ-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$M(t) = a + bt^{\ heta -1}$$\\end{document}, where a,b>0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$a, b > 0$$\\end{document} are given constants; 1<p<N\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$1<p<N$$\\end{document}, Δp=div(|∇u|p-2∇u)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta _p = \ ext {div}(|\ abla u|^{p-2}\ abla u)$$\\end{document} is the p-Laplacian operator; potential V∈C2(RN)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$V \\in C^2({\\mathbb {R}}^N)$$\\end{document}; f is monotonic function with suitable growth conditions. We obtain the existence of a positive high energy solution for θ∈1,2N-μN-p\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ heta \\in \\left[ 1, \\frac{2N-\\mu }{N-p}\\right) $$\\end{document} via the Pohožaev manifold and linking theorem. Apart from this, we also studied the radial symmetry of solutions of the associated limit problem.

Research on the influence of foaming silica gel-filled on low-velocity impact performance of M-type GFRP foldcore sandwich structure

The M-type GFRP foldcore was prepared by thermal pressing method, and was bonded with the panel to obtain the complete foldcore sandwich structure and filled the core with foaming silica gel. The influence of filling foam, impact energy and impact position on the damage mode and impact dynamic response under the low-velocity impact of GFRP M-type foldcore sandwich structure is studied through low-velocity experiment. The results show that the impact resistance of Node-impact is better than the Base-impact under low energy impact, while the Node-impact is worse than the Base-impact under high energy impact. Filling foam could effectively improve the impact properties of the foldcore sandwich plate and decrease the damage degree of the sandwich plate. In addition, filling foam could absorb about 16–26% more energy than the empty core sandwich plate.

Sustainable energy transition in Bangladeshi academic buildings: A techno-economic analysis of photovoltaic-based net zero energy systems

Bangladesh faces challenges with global carbon emissions and energy security due to its heavy reliance on imported fossil fuels. This paper investigates the techno-economic viability of photovoltaic (PV) systems for achieving net-zero energy in academic buildings as a sustainable alternative. The study evaluates the performance of PV systems based on factors including annual energy production, capacity factor, net-zero energy potential, self-consumption/sufficiency ratio, renewable fraction, levelized cost of energy (LCOE), net present value (NPV), payback period, profitability index (PI), and carbon emission reduction. The results indicate that optimally sized PV systems can generate net positive energy: 6.18 MWh for universities, 4.04 MWh for high schools, and 3.62 MWh for primary schools. Economic viability was assessed under two billing methods (net metering and all energy buy/sell), and all cases showed positive NPV and PI values greater than 1. Decarbonization analysis revealed significant reductions in CO2 emissions: 2026.5 tons for universities, 18.9 tons for high schools, and 9.7 tons for primary schools. Finally, a sensitivity analysis assessed the optimal PV system size for seven other regions in Bangladesh. These findings suggest that the widespread adoption of PV systems in academic buildings can play a crucial role in achieving net-zero energy, contributing significantly to the government and policymakers' pursuit of sustainable development goals.

A Review of Lawson Criterion for Nuclear Fusion

In the pursuit for abundant clean energy from nuclear fusion, the Lawson Criterion is cited by fusion researchers and experimentalists as the condition to exceed for fusion of atomic nuclei to occur. In his 1955 paper J.D. Lawson analyzed a fusion plasma conforming to thermodynamic principles at steadystate but with stated omissions and simplifications. Modern fusion researchers developed many incantations of the Lawson Criterion urging their brand leads to fusion ignition, necessarily to sell a rational fusion hypothesis and attract research funding. Others have shown how confined fusion in the laboratory cannot satisfy a positive energy balance due to energy losses from the system. A literature search for "fusion energy balance" shows a suspicious absence of this sanity-check to verify the energy condition was met. This paper applies conservation of energy from classical thermodynamics to a fusion plasma and summarizes eleven modern Lawson-like interpretations in a uniform way, doing so shows the requirements for fusion ignition are not met. Indeed despite billions of speculative dollars spent, sustained laboratory fusion has not been demonstrated in any experimental apparatus built and tested to date worldwide. Heed the warning, in 1955 John D. Lawson wrote: “To conclude we emphasize that these conditions, though necessary are far from sufficient. The working cycle that has been assumed is very optimistic.”

Towards Positive Energy Districts

Positive energy districts (PEDs) are a vision to enable and foster the energy transition in the building sector. The integration of heat pumps (HP) in buildings and districts to achieve a net positive energy balance is crucial. The efficiency of the electric and thermal energy system of districts can be improved with the use of HPs. This refers to both, the upgrade of waste heat and benefiting from simultaneous use and generation of energy in buildings at different temperature levels (space heating, DHW, space cooling/dehumidification) and includes self-consumption of on-site renewable electricity generation. Using the example of the new district Innsbruck Campagne, HP integration options as well as photovoltaic (PV) integration potentials are evaluated with respect to reaching a positive energy balance. Both simulation results as well as monitoring results are presented. The importance of very high building efficiency standards as well as well-designed and dimensioned systems to achieve a positive energy balance and to reduce the so-called winter gap is highlighted.

Biexcitons and quadrons in self-assembled quantum dots

We theoretically study biexcitons and quadrons in quantum dots with parabolic confinement and give a complete comparison between the two excitations. The calculation of quadron and biexciton binding energies as functions of electron-to-hole confinement potentials and mass ratios, using the unrestricted Hartree–Fock method, shows the essential differences between biexcitons and quadrons. The crossover between the negative and positive binding energies is indicated. The effect of an external magnetic field on the quadron and biexciton binding energies has also been investigated. In addition, the crossover between anti-binding and binding of both excited quadron and biexciton states in a certain range of the electron-to-hole oscillator length ratios has been found.

A comparative study of wormhole geometries under two different modified gravity formalism

In the current article, we discuss the wormhole geometries in two different gravity theories, namely F(Q,T)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ exttt{F}(\ exttt{Q, T})$$\\end{document} gravity and F(R,T)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ exttt{F}(\ exttt{R, T})$$\\end{document} gravity. In these theories, Q\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ exttt{Q}$$\\end{document} is called a non-metricity scalar, R\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ exttt{R}$$\\end{document} stands for the Ricci scalar, and T\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ exttt{T}$$\\end{document} denotes the trace of the energy–momentum tensor (EMT). The main goal of this study is to comprehensively compare the properties of wormhole solutions within these two modified gravity frameworks by taking a particular shape function. The conducted analysis shows that the energy density is consistently positive for wormhole models in both gravity theories, while the radial pressure is positive for F(Q,T)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ exttt{F}(\ exttt{Q, T})$$\\end{document} gravity and negative in F(R,T)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ exttt{F}(\ exttt{R, T})$$\\end{document} gravity. Furthermore, the tangential pressure shows reverse behavior in comparison to the radial pressure. By using the Tolman-Oppenheimer-Volkov (TOV) equation, the equilibrium aspect is also described, which indicates that hydrostatic force dominates anisotropic force in the case of F(Q,T)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ exttt{F}(\ exttt{Q, T})$$\\end{document} gravity theory, while the reverse situation occurs in F(R,T)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ exttt{F}(\ exttt{R, T})$$\\end{document} gravity, i.e., anisotropic force dominates hydrostatic force. Moreover, using the concept of the exoticity parameter, we observed the presence of exotic matter at or near the throat in the case of F(Q,T)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ exttt{F}(\ exttt{Q, T})$$\\end{document} gravity while matter distribution is exotic near the throat but normal matter far from the throat in F(R,T)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ exttt{F}(\ exttt{R, T})$$\\end{document} gravity case. In conclusion, precise wormhole models can be created with a potential NEC and DEC violation at the throat of both wormholes while having a positive energy density, i.e., ρ>0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\rho >0$$\\end{document}.

The hydrophilicity mechanism of anatase and rutile (110) TiO2 films based on donor-acceptor complexes

When the surface of TiO2 is exposed to ultraviolet (UV) light, its hydrophilicity increases initially and then contact angle relaxation progresses over time. We investigated the source mechanism and working principles of long-lasting hydrophilicity in an ambient environment. Previously, we reported that the amount of donor-acceptor complexes (DACs) generated by polarizable OH groups with strong charge polarity is critical for maintaining long-lasting hydrophilicity (>90 days) on an anatase surface. In less reactive TiO2 films with low surface energy, a fast relaxation occurs due to the loss of polarizable OH groups. In this research, quantitative four-peak X-ray photoelectron spectroscopy analysis with TiO2 O 1 s spectra surface analysis was used to determine the relative amount of DACs and the binding energy shifting of water adsorbates on single crystal rutile (110) and polycrystalline anatase after UV exposure or plasma treatment. Films treated with oxygen or argon plasma and/or UV were analyzed and compared to suggested mechanisms that can occur on the surface of the TiO2 phase. All treated rutile (110) films except those treated with an Ar plasma exhibited rapid contact angle relaxation during the first 3 days, and the angle increased gradually to >50° over 14 days. In contrast, all anatase films retained long-lasting hydrophilicity, demonstrating a <∼10° contact angle over 56 days. At the first measurement, the binding energies were shifted for rutile (110) treated with O2 plasma and O2 plasma+UV films, demonstrating Ti–OH and DAC values of +0.15 eV each. However, the Ti–OH and DACs of all anatase films were located in the negative binding energy position, indicating that the DACs of rutile (110) were unstable due to a relatively weak bonding. In addition, the IOH/Ibulk intensity ratio of Ti–OH for rutile (110) treated with an O2 plasma increased significantly from 20 % to 37 %. However, the intensity ratio for O2 plasma+UV increased only from 20 % to 23.8 %. This result in combination with the binding energy shifting tendency indicates that relaxed OH groups increased rapidly without UV treatment. When rutile (110) was irradiated with UV, the effect of photoinduced electron-hole pairs shown with Ti 2p spectra was much shorter than that of anatase. Differences in relaxation occurred in both phases due to the charge polarity effect between rutile (110) and anatase, the unstable DACs related to weak OH groups, and the difference in surface characteristics. Using single crystal rutile (110) with a well-defined surface, these experiments validated further the DAC mechanism and theory presented by our group. Specifically, we confirmed that both the amount of DACs and the binding energy position shifting are important for long-term hydrophilicity.

Theoretical Study of Carbon K‐Edge Energy‐Loss Near‐Edge Structure Spectra in the Ordered Mo2TiAlC2 MAX and Mo2TiC2 MXene

By means of density functional theory, the energy‐loss near‐edge structure (ELNES) of carbon K‐edge of Mo2TiAlC2 and corresponding MoTiC2 Mxene at orientational‐independent condition is dealt with. Compared to the MAX (M is transition metal, A is an elment from group 13–16, X is C or N) phase, the energy separations increase between the main spectral features at the C K edge of Mo2TiC2 MXene owing to the structural change and decreased bond length. The dispersions of the C K edge in both systems are similar to p‐symmetry densities of states. It is indicated that the source of the first fine structure at the C 1s edge in both phases mainly comes from the electron transfer to px + py‐like character. The other fine structures result from the transition to hybridization of pz and px + py states with the prominent contribution of px + py‐like character. Moreover, the comparison of C K‐edge ELNES spectra in three Mo‐based compounds reveals that, ongoing from Mo2TiAlC2 to Mo2TiC2 and then to Mo2C, the energy position of the fine structures is shifted to higher energies (blueshifted), due to the quantum confinement effects and the change of the chemical environment around the excited carbon.

Temperature dependence investigations of molecular interactions and excess thermodynamic parameters of binary mixtures of ionic liquids and water using Flory's statistical theory

AbstractFlory's Statistical Theory (FST) has been applied to investigate excess thermodynamical parameters viz., excess enthalpy, excess entropy, and excess Gibbs free energy for eight binary mixtures of ionic liquids and water at different concentration and temperatures. The concentration and temperature dependent variations of excess enthalpy suggest that ionic liquid mixtures exhibit an endothermic nature and the presence of weak dispersive forces among their constituents. The positive excess Gibbs free energy of mixing points out that the pure components do not mix thoroughly for the systems under study. Overall, these binary systems are thermodynamically unfavorable suggesting that the mixing of ionic liquids and water is not energetically favored or spontaneous. Experimental molar volumes are compared with those calculated using FST and these values show excellent agreement. It affirms the validity of FST's application to these systems. Additionally, some partial properties have also been determined to explore the solute‐solvent interactions. The Redlich‐Kister (R‐K) polynomial model has been applied to excess thermodynamical parameters The high R2 values and low standard deviation values confirm the validity of fitting the RK polynomial model to the functions obtained using FST of liquids for these systems within the given temperature range.

Mechanistic evaluation of contrasting modulation in conformation and catalytic performance of urease by surface interaction of graphene oxide and amine- functionalized graphene oxide nanosheets

The increasing use of graphene-based nanomaterials raises concerns about their potential environmental impact as ecotoxicants. This article examines the interaction and effects of graphene oxide (GO) and its amine-derived (GONH2) 2-D nanosheets on urease dynamics, a crucial enzyme in soil nutrient cycling, through spectroscopic, microscopic, and computational analyses. The findings reveal the distinct interaction mechanisms: GO formed ground - and excited-state complexes with urease; thus, fluorescence quenching was static and dynamic via hydrophobic interaction. In contrast, GONH2 nanosheets formed a ground-state complex by static quenching involving Van der Waals and hydrogen bonding. These interactions were energetically favored and altered tryptophan (Trp) residues’ microenvironment more than tyrosine (Tyr). The average exciton lifetime of urease in the presence of GO have decreased from 4.34 ns to 3.647 ns at the mere concentration of 7.11 µM, while for GONH2, no discernable change (4.16 ns) was observed even at the concentration of 16.75 µM. Primarily, the strong interaction of GO leads to the rearrangement of polypeptide structure, reduced α-helices to 12 %, and increased β-sheets by six times. In contrast, with GONH2, α-helices were reduced to 79 %, and β-sheets were increased by 1.8 times at the similar concentration. Molecular docking revealed that neither GO nor GONH2 interacted with the active site of urease, and binding was primarily via hydrophobic, Van der Waals, and hydrogen bonding, concurrent with in-vitro incubation results. Positive total energy (3.85 kJ mol−1) during molecular docking analysis of urease-GO interaction and inhibition in enzyme activity to 62 %, altered Vmax value (0.04606 ± 0.001 mM/s), without affecting the Km (4.78045 ± 0.12 mM) suggested that inhibition was noncompetitive and steric clashes due to disruptive binding might drove the inhibition. Meanwhile, negative total internal energy (-3.97 kJ mol−1) during urease + GONH2 binding and enhanced enzymatic activity by 32 % in-vitro without altering Vmax (0.063091 ± 0.003 mM/s) and Km (4.953943 ± 0.2 mM) values suggested that urease's binding site was well-complemented by GONH2 nanosheets, serving as a redox-mediator and radical-quencher.