Value Of Function Research Articles

On q-Painlevé VI and the geometry of Segre surfaces

In the context of q-Painlevé VI with generic parameter values, the Riemann–Hilbert correspondence induces a one-to-one mapping between solutions of the nonlinear equation and points on an affine Segre surface. Upon fixing a generic point on the surface, we give formulae for the function values of the corresponding solution near the critical points, in the form of complete, convergent, asymptotic expansions. These lead in particular to the solution of the nonlinear connection problem for the general solution of q-Painlevé VI. We further show that, when the point on the Segre surface is moved to one of the sixteen lines on the surface, one of the asymptotic expansions near the critical points truncates, under suitable parameter assumptions. At intersection points of lines, this then yields doubly truncated asymptotics at one of the critical points or simultaneous truncation at both.

Evaluation of the Effectiveness of Sex Determination in the Great Cormorant (Phalacrocorax carbo) Based on External Measurements.

The possibility of sex identification of birds has substantial importance for studies on different aspects of bird ecology and behaviour. Using discriminant functions is becoming increasingly popular in studies of bird species that are monomorphic in plumage characteristics because they are cheap, hardly invasive and may be applied to data collected in the past. In this paper, we provide a discriminant function to sex great cormorants using external measurements. Males were larger than females in all linear body measurements, but there were no significant differences between adults and juveniles. Thus, data on juveniles and adults within a sex was combined. Discriminant equations with the most commonly used linear measurements, wing length and bill length, were provided. If identifying birds with discriminant function values D2 < -1.256 as females and those with D2 > 0.916 as males, 99% of birds will be correctly sexed. The method presented here makes it possible to account for sex-specific patterns in ecological studies of the great cormorant and may be applied to data collected in the past. The cross-application of discriminant functions developed for other populations of the great cormorant produces a 5.4% and 7.5% misclassification rate for birds from northern Poland using discriminant equations developed for populations in Greece and the Netherlands, respectively.

Quantifying Regulating Ecosystem Services of Urban Trees: A Case Study of a Green Space at Chungnam National University Using i-Tree Eco

Urban green spaces (UGSs) provide numerous ecosystem services (ESs) that are essential to the well-being of the residents. However, these services are often neglected in regional urban development and spatial planning. This study quantified the ESs of a 10.25 ha UGS at Chungnam National University, Daejeon, Republic of Korea, comprising 27 species with 287 tree individuals, using i-Tree Eco. Key regulating ESs investigated included air pollution removal, carbon storage and sequestration, oxygen production, energy use reduction, avoidance of surface runoff, and replacement and functional values. Results revealed significant annual environmental benefits: 131 kg air pollutants removed (USD 3739.01 or ₩5.16 M), 1.76 Mg carbon sequestered, which is equivalent to 0.18 Mg CO2 ha−1 yr−1 (USD 289.85 or ₩0.40 M), 2.42 Mg oxygen produced, energy savings (including carbon offset) valued at USD 391.29 (₩0.54 M), and 203 m3 reduction in surface runoff (USD 413.09 or ₩0.57 M). The annual total benefits of these urban trees amounted to USD 4833.86 (₩6.67 M), USD 16.83/tree, or USD 0.089/capita. Additionally, these trees had replacement and functional values estimated at USD 311,115.17 (₩429.3 M). The study underscores that species selection and abundance of urban trees are fundamental for maximizing the ES delivery in urban areas, highlighting the role of UGSs in ecological and economical sustainability in cities. These insights are valuable for urban planners and policymakers to optimize benefits of UGSs in cities.

Accelerated mustard [Brassica juncea (L.) Czern &amp; Coss] improvement for salt tolerance: Photosynthetic traits and selection indices

AbstractPhotosynthetic traits can sense and signal abiotic stress at early growth stages of mustard [Brassica juncea (L.) Czern &amp; Coss]. The integration stress responses with multiple selection indices can select the fittest/tolerant genotypes. With this goal, a set of 210 diverse mustard genotypes were phenotyped under control and salt‐stress (electrical conductivity = 12 dS m−1). Significant dynamic response of the plant to salt stress with reduction for all morpho‐physiological traits and genotype × treatment interaction was observed under salinity. A higher accumulation of Na+ was recorded in the roots, followed by shoots. A close correspondence between phenotypic coefficient of variation and genotypic coefficient of variation under control and salt stress conditions results in high heritability (h2) in broad sense. A significant negative association between shoot and root Na+ content and rate of photosynthesis also indicated that Na+ was significantly restricted in the root. This was not found to be efficient because considerable Na+ buildup was observed in the shoot. Multiple trait‐based indices, such as membership function value of salinity tolerance, classical Smith–Hazel index, factor analysis ideotype–best linear unbiased prediction index, and multi‐trait genotype‐ideotype distance index, deduced CS 2009‐159, CS 2009‐420, CS 2009‐124, and Swarn Jyoti (RH‐9801) are promising for identifying salt‐tolerant genotypes that can serve as donors for the development of salt‐tolerant cultivars.

Padé Approximations and Irrationality Measures on Values of Confluent Hypergeometric Functions

Padé approximations are approximations of holomorphic functions by rational functions. The application of Padé approximations to Diophantine approximations has a long history dating back to Hermite. In this paper, we use the Maier–Chudnovsky construction of Padé-type approximation to study irrationality properties about values of functions with the form f(x)=∑k=0∞xkk!(bk+s)(bk+s+1)⋯(bk+t), where b,t,s are positive integers and obtain upper bounds for irrationality measures of their values at nonzero rational points. Important examples includes exponential integral, Gauss error function and Kummer’s confluent hypergeometric functions.

Identification and molecular mechanism of novel hypoglycemic peptide in ripened pu-erh tea: Molecular docking, dynamic simulation, and cell experiments

Ripened pu-erh tea is known to have beneficial hypoglycemic properties. However, it remains unclear whether the bioactive peptides produced during fermentation are also related to hypoglycemic potential. This study aimed to identify hypoglycemic peptides in ripened pu-erh tea and to elucidate their bioactive mechanisms using physicochemical property prediction, molecular docking, molecular dynamics simulations, and cell experiments. Thirteen peptides were identified by liquid chromatography–mass spectrometry/mass spectrometry (LC-MS/MS). Among them, AADTDYRFS (AS-9) and AGDGTPYVR (AR-9) exhibited high α-glucosidase inhibitory activity, with half-maximal inhibitory concentration (IC50) values of 0.820 and 3.942 mg/mL, respectively. Molecular docking and dynamics simulations revealed that hydrogen bonding, hydrophobic interactions, and van der Waals forces assist peptides AS-9 and AR-9 in forming stable and tight complexes with α-glucosidase. An insulin-resistance (IR)-HepG2 cell model was established. AS-9 was non-toxic to IR-HepG2 cells and significantly increased the glucose consumption capacity, hexokinase, and pyruvate kinase activities of IR-HepG2 cells (p < 0.05). AS-9 alleviated glucose metabolism disorders and ameliorated IR by activating the IRS-1/PI3K/Akt signaling pathway and increasing the expression levels of MDM2, IRS-1, Akt, PI3K, GLUT4, and GSK3β genes. In addition, no hemolysis of mice red blood cells red blood cells occurred at concentrations below 1 mg/mL. This work first explored hypoglycemic peptides in ripened pu-erh tea, providing novel insights for enhancing its functional value.

High-Throughput Sequencing Analysis Revealed a Preference for Animal-Based Food in Purple Sea Urchins.

Sea urchins play an important role in marine ecosystems. Owing to limitations in previous research methods, there has been insufficient understanding of the food sources and ecological functional value of purple sea urchins, leading to considerable controversy regarding their functional positioning. We focused on Daya Bay as the research area, utilizing stable isotope technology and high-throughput sequencing of 16S rDNA and 18S rDNA to analyze sea urchins and their potential food sources in stone and algae areas. The results showed that the δ13C range of purple sea urchins in the stone area is -11.42~-8.17‱, and the δ15N range is 9.15~10.31‱. However, in the algal area, the δ13C range is -13.97~-12.44‱, and the δ15N range is 8.75~10.14‱. There was a significant difference in δ13C between the two areas (p < 0.05), but there was no significant difference in δ15N (p > 0.05). The main food source for purple sea urchins in both areas is sediment. The sequencing results of 18S rDNA revealed that, in the algal area, the highest proportion in the sea urchin gut was Molluska (57.37%). In the stone area, the highest proportion was Arthropoda (76.71%). The sequencing results of 16S rDNA revealed that, in the algal area, Bacteroidetes was the dominant group in the sea urchin gut (28.87%), whereas, in the stone area, Proteobacteria was the dominant group (37.83%). Diversity detection revealed a significant difference in the number of gut microbes and eukaryotes between the stone and algal areas (p < 0.05). The results revealed that the main food source of purple sea urchins in both areas is sediment, but the organic nutritional value is greater in the algal area, and the richness of microbiota and eukaryotes in the gut of purple sea urchins in the stone area is greater. These results indicated that purple sea urchins are likely omnivores and that the area where they occur impacts their growth and development. The results of this study provide a theoretical basis for the restoration of wild purple sea urchin resources and the selection of areas for restocking and release.

The interdependence of functional properties of a football boot outsole during the shape optimisation process

The aim of this study was to investigate the relationship and interdependence of functional properties of the football boot outsole during the shape optimisation process. Sensitivity-based shape optimisation technique was applied to a football boot outsole to modify its thickness to have various functional properties. Three functional properties of the outsole, which are the midfoot and forefoot bending stiffness and torsional stiffness, were investigated. The midfoot and forefoot bending stiffness were measured via a three-point bending test. Torsional stiffness was measured via a bespoken mechanical test. The functional properties were evaluated by finite element models, representing the developed mechanical tests. Through the optimisation tasks, it was explored how much each functional property could be changed individually and also while minimising the influence of the other two functional properties. With the modification of the regions of the outsole to optimise for various individual target functional property values, the changes in the other two functional properties were observed. Lastly, the optimised outsoles from the finite element models were 3D printed and tested to determine the accuracy of the process. Within a permitted thickness limit, modifying the region associated with the torsional stiffness measurement influenced the other two functional properties the most. Especially, the midfoot bending stiffness was influenced more than the forefoot bending stiffness. On the other hand, the areas involved in the midfoot and forefoot bending stiffness measurements were independent of each other. The conclusions drawn in this study are limited to the particular outsole design, single outsole component and mechanical test utilised.

Shaping of the risk of a series-parallel manufacturing structure maintenance according to quasi-coherence and the [formula omitted]-th survival value

The paper presents the authors’ model for determining the probability value of the survival function of the difference of two random variables: TP – the amount of time of correct operation and TB – the amount of time of failure. For this purpose, the concept of K-th survival value is introduced. The K-th survival value defines the probability that the total time of correct operation of the production system will be longer by at least k time units (for k≥0) than the total amount of time of failures. The model was exemplified by a real production system with a series–parallel structure. In the nesting manufacturing structure, the availability of machines determines the number and the type of flow streams of the processed material. To formalise the chains of relations at a given Δt, this paper utilises the quasi-coherence property. The paper identifies four possible cases of system operation: 1) a fully operational system in which every machine is capable of meeting the assumed production schedule; 2) a system which has lost the property of quasi-coherence (certain system objects are in an inoperable state) but it is possible to meet the assumed production schedule; 3) a system which has lost the property of quasi-coherence but the assumed task schedule is possible to meet after redefining the material flow streams; 4) a system which has lost the property of quasi-coherence and it is impossible to meet the assumed production schedule. Based on the definition of the survival function [1] S of the random variable T: ST:=PT>τ=1-FTτ,τ∈R, the concept of K-th survival value was introduced. For possible cases, K-th survival value was defined as: KT1,Ti=PT1-Ti≥k=1-FT1-Tik (for i=2,3,4), where T1 and Ti are random variables with given probability distributions. In turn, k is a deterministic value that determines the total number of time units of correct system operation in relation to the total failure time. The application of the developed algorithm enables the system to be analysed in terms of three aspects: (1) to determine the probability of on-time execution of tasks, taking into account historical values of machine failure and correct operation durations; (2) to determine the stability of the system based on empirical data; (3) to monitor the level of risk in real time. The paper validates the model by determining the stability of the analysed system for real machine failure data. The introduced criterion of stochastic stability of the production system has been verified for data in which distributions of correct operation times and failure times are random variables from the family of Gamma distributions. The presented model can be included in the group of multifactorial risk assessment methods.

The impact of Fintech innovations on digital currency adoption: a blockchain-based study in India

Purpose The purpose of this study is to integrate customer value theory (CVT) and protection motivation theory (PMT) to understand the factors that have an impact on customer experience, e-trust and intention to recommend, which influence the adoption behaviour of digital currency users. Design/methodology/approach A purposive sampling technique was used, and data were gathered through an online survey of 414 respondents. The measurement and structural models were tested using partial least squares structural equation modelling to establish linkages between the constructs. Findings Functional, emotional and social values positively impact customer experience. Furthermore, perceived severity, perceived vulnerability, response efficacy and self-efficacy had a positive impact on e-trust. E-trust positively affects customer experience and intention to use the digital currency directly. The study demonstrated that perceived value and protection motivation factors play a significant role in influencing the use of digital currency. Practical implications For managers and policymakers interested in the Indian digital currency market, it is suggested that functional utility and emotional and social benefits can enhance user satisfaction. In an e-trust model, user education to increase risk and protection awareness, effectiveness of responses and self-efficacy are critical to building e-trust. Originality/value Building on CVT and PMT’s usage in the broader financial services domain, this research empirically confirms the significance of perceived value and protection motivation factors while adopting digital currency. It provides an extensive and multifaceted approach to comprehending customer involvement and trust in digital financial services, thus enhancing the theoretical and empirical knowledge of both the fintech and blockchain industries.

Sleep defined by arousal threshold reveals decreases in corticocortical functional correlations independently from the conventional sleep stages.

Sleep research and sleep medicine have benefited from the use of polysomnography but have also suffered from an overreliance on the conventional, polysomnography-defined sleep stages. For example, reports of sleep-specific brain activity patterns have, with few exceptions, been constrained by assessing brain function as it relates to the conventional sleep stages. This limits the variety of sleep states and underlying activity patterns that one can discover. If undiscovered brain activity patterns exist during sleep, then removing the constraint of a stage-specific analysis may uncover them. The current study used all-night functional magnetic resonance imaging sleep data and defined sleep behaviorally with auditory arousal threshold (AAT) to begin to search for new brain states. It was hypothesized that, during sleep compared to wakefulness, corticocortical functional correlations would decrease. Functional correlation values calculated in a window immediately before the determination of AAT were entered into a linear mixed effects model, allowing multiple arousals across the night per subject into the analysis. The hypothesis was supported using both correlation matrices of brain networks and single seed-region analyses showing whole-brain maps. This represents a novel approach to studying the neuroanatomical correlates of sleep with high spatial resolution by defining sleep in a way that was independent from the conventional sleep stages. This work provides initial evidence to justify searching for sleep stages that are more neuroanatomically localized and unrelated to the conventional sleep stages.

Relationship between serum uric acid levels and complement functional activity

Uric acid (UA) is the end product of purine metabolism and a substance that promotes a chronic inflammatory process. One of the mechanisms of inflammation associated with the UA is the ability of its crystals, mainly monosodium urate, to activate NLRP3 inflammasomes, classifying UA and its salt crystals as damage-related molecular patterns (DAMPs). These crystals also activate the complement system, leading to increase in C3a, C4a, and C5a concentrations and excessive consumption of complement system proteins. It has been known for a long time that UA is able to activate complement, but the relationship between hyperuricemia and complement system functional activity, which can be assessed by complement-mediated hemolysis, remains unclear. In this study, we have made an attempt to estimate the UA concentration that does not lead to spontaneous complement system activation. The study assessed the relationships between the parameters of complement functional activity and some blood biochemical data with UA concentration ([UA]) using correlation analysis. The rate (Vlys) and time of 50% hemolysis (T50) were considered as indicators of complement functional activity, and their relationship was demonstrated using exponential functions y = a*e[x], which takes the form y = [UA]*e[C3]. Concentration of C3 is the argument of the function, base of degree is the base of the natural logarithm, and the proportionality coefficient equal to the UA concentration. Correlation analysis showed the inverse dependent between function values and the corresponding values of T50 (r = -0.83, p 0.0001) in the range of UA concentration exceeding 370 umol/L, which is near to the upper limit of the normal level for women and is within the normal range for men. Thus, the approach to assess the effect of UA on complement activation using the analysis of the complement hemolytic activity is effective to demonstrate the pathogenetic function of UA in the development of the inflammatory process without involving inflammasomes through the direct effects on complement activation processes. The relationships demonstrated suggest that the upper limits of the range of “normal” UA concentrations are arbitrary, and their revision is likely advisable.

A two-phase sequential algorithm for global optimization of the standard quadratic programming problem

AbstractWe introduce a new sequential algorithm for the Standard Quadratic Programming Problem (StQP), which exploits a formulation of StQP as a Linear Program with Linear Complementarity Constraints (LPLCC). The algorithm is finite and guarantees at least in theory a $$\delta $$ δ -approximate global minimum for an arbitrary small $$\delta $$ δ , which is a global minimum in practice. The sequential algorithm has two phases. In Phase 1, Stationary Points (SP) with strictly decreasing objective function values are computed. Phase 2 is designed for giving a certificate of global optimality for the last SP computed in Phase 1. Two different Nonlinear Programming Formulations for LPLCC are proposed for each one of these phases, which are solved by efficient enumerative algorithms. New procedures for computing a lower bound for StQP are also proposed, which are easy to implement and give tight bounds in general. Computational experiments with a number of test problems from known sources indicate that the two-phase sequential algorithm is, in general, efficient in practice. Furthermore, the algorithm seems to be an efficient way to study the copositivity of a matrix by exploiting an StQP with this matrix.

Physicochemical and textural properties of gummy candies prepared with fruit vinegar

Foods with additional functional value derived from natural sources are becoming more and more in demand these days, including confectionary products. Therefore, the study aimed to develop a gummy candy recipe, enriched with different fruit vinegars and determine the components' effect on the products' mineral, acid, sugar, antioxidant, and polyphenol content, and texture of the confectionery products with analytical methods. In terms of macroelement content, potassium was present in the largest amount in the tested candies (167.87 and 178.83 mg kg-1) and liquid ingredients (57,71–306.93 mg kg-1). In the case of microelements, iron (4.81, 4.79 mg kg-1) and boron (4.62, 4.49 mg kg-1) were significant in the products, iron is also found in gelatin in significant quantities (3.51 mg kg-1), however, boron came exclusively from fruit-derived components (1.02–9.40 mg kg-1). Among the tested organic acids, malic acid (21.67–46.12 mg g-1), and acetic acid (47.74–50.06 mg g-1) were significant in both the raw materials and products, while the fructose content (2.44–439.35 mg g-1) was prominent among the sugars, but the glucose (75.99–163.44 mg g-1) and sucrose (73.61–157.00 mg g-1) content were also significant. Unfortunately, the polyphenol (1.37–1.46 mg GAE/g) and antioxidant (0.29–0.75 mg AAE/g) content of the products was not significant, maybe because of their heat sensitivity. In terms of the texture of the candies, the two candies prepared with different fruit vinegars had similar textural properties, however, in terms of hardness (3523.10 N/m2), gumminess (3266.25 N/m2), and chewiness (3425.33 N/m2) the gummy candy with apple cider vinegar proved to be better. Unlike many other confectionery products, the sugar content of the developed product is provided only by the used the apple concentrate, it does not contain added sugar or sweeteners. The addition of fruit vinegars has been proven to have a positive effect on the nutritional values of candies. By replacing gelatin with another gelling agent, the product can also be prepared in a vegan form.

Dispersion network-transition entropy: A metric for characterizing the complexity of nonlinear signals.

Extracting meaningful information from signals has always been a challenge. Due to the influence of environmental noise, collected signals often exhibit nonlinear characteristics, rendering traditional metrics inadequate in capturing the dynamic properties and complex structures of signals. To address this challenge, this study proposes an innovative metric for quantifying signal complexity-dispersion network-transition entropy (DNTE), which integrates the concepts of complex networks and information entropy. Specifically, we assign single cumulative distribution function values to network nodes and utilize Markov chains to represent links, transforming nonlinear signals into weighted directed complex networks. Subsequently, we assess the importance of network nodes and links, and employ the mathematical expression of information entropy to calculate the DNTE value, quantifying the complexity of the original signal. Next, through extensive experiments on simulated chaotic models and real underwater acoustic signals, we confirm the outstanding performance of DNTE. The results indicate that, compared to Lempel-Ziv complexity, permutation entropy, and dispersion entropy, DNTE not only more accurately reflects changes in signal complexity but also exhibits higher computational efficiency. Importantly, DNTE demonstrates optimal performance in distinguishing different categories of chaotic models, ships, and modulation signals, showcasing its significant potential in extracting effective information from signals.

Optimal charging of electric vehicles in smart stations and its effects on the distribution network using meerkat optimization algorithm

The proliferation of electric vehicles (EVs) presents a significant challenge and opportunity for the energy sector. This study proposes a novel approach for optimizing EV charging within smart stations, considering its impact on the distribution network. Leveraging the Meerkat Optimization Algorithm (MOA), we address the complex optimization problem of balancing EV charging demands with grid constraints. Navigating distribution grid energy management complexities, including renewable resources and dynamic demand, is challenging. We introduce a sophisticated optimization model tailored for grid operations, featuring meticulous formulations for energy management. The model optimizes battery usage, EV energy management, compensator utilization, and distributed generation dispatch. Through extensive simulations, we demonstrate the approach's effectiveness in minimizing charging costs, reducing grid congestion, and enhancing overall system performance. The multi-objective function minimizes energy losses, power purchases, load curtailment, distributed generation, and battery/EV expenses over 24 h. Simulations validate a significant reduction in the distribution grid's operating cost. This research highlights the potential of advanced optimization techniques in smart charging infrastructure to facilitate widespread EV adoption while ensuring grid reliability and efficiency. Incorporating electric vehicles (EVs) into the system yields significant improvements across performance indicators compared to scenarios without EVs. Results indicate a 19 % reduction in the objective function value, with a notable 74 % decrease in energy purchase and a 60 % reduction in energy losses. Additionally, load shedding decreases by approximately 75 %, while voltage deviation decreases by around 44 %. Importantly, no PV or WD curtailment is observed with EV integration, showcasing its compatibility with renewable energy generation profiles and emphasizing its potential to enhance system efficiency, reliability, and sustainability.

Factors influencing the survival status of the hip joint in post-collapse femoral head necrosis

BackgroundDespite hip function typically deteriorating in the post-collapse stage of osteonecrosis of the femoral head (ONFH), some patients can still demonstrate long-term favorable hip function, a state termed “survival with collapse”. This study aims to identify the characteristics of patients suitable for “survival with collapse” in cases of ONFH.MethodsThis cross-sectional study included 65 patients (87 hips) diagnosed with post-collapse ONFH for ≥ 3 years (average 9.1 years, range 3–23 years). Hip function was assessed using the Harris Hip Score (HHS). Demographic, clinical, and radiographic data were compared between the favorable group (HHS > 80) and the poor group (HHS ≤ 80). Independent protective factors for hip function were identified by multivariate analysis and receiver operating characteristic (ROC) curve analysis was further applied to evaluate these factors’ diagnostic efficacy.ResultsThe favorable and poor groups included 46 and 41 hips, respectively. Significant differences were found in body mass index (BMI), Association Research Circulation Osseous (ARCO) stage, collapse degree, Japanese Investigation Committee (JIC) classification, necrotic size, and hip subluxation between the two groups (p < 0.05). Multivariate logistic regression identified collapse < 3 mm(OR:14.49, 95%CI: 3.52–59.68, p < 0.001), JIC types B (OR: 11.08, 95% CI: 1.07-115.12, p < 0.05) and C1(OR: 5.18, 95% CI: 1.47–18.20, p < 0.05) as independent protective factors for hip function, while BMI (OR: 0.76, 95% CI: 0.59–0.97, p = 0.029) was an independent risk factor. ROC curve analysis demonstrated that both collapse degree (AUC = 0.798, sensitivity = 91.3%, specificity = 68.3%, p < 0.0001) and JIC classification (AUC = 0.787, sensitivity = 80.4%, specificity = 73.2%, p < 0.0001) had satisfactory diagnostic value for hip function. Combining JIC classification and collapse degree (AUC = 0.868, sensitivity = 76.1%, specificity = 85.4%, p < 0.0001) significantly enhanced diagnostic efficacy compared to using either alone (p < 0.05).ConclusionIn ONFH, femoral head collapse does not necessarily determine a poor prognosis. Patients with mild collapse (< 3 mm) and preserved anterolateral wall are more likely to retain satisfactory hip function, making them candidates for “survival with collapse.”

Loop correction and resummation of vertex functions for a self interacting scalar field in the de Sitter spacetime

We consider a massless and minimally coupled self interacting quantum scalar field theory in the inflationary de Sitter background of dimension four. The self interaction potential is taken to be either quartic, λϕ4/4!, or quartic plus cubic, λϕ4/4!+βϕ3/3! (λ>0). We compute the four and three point vertex functions up to two loop. The purely local or partly local part of these renormalised loop corrected vertex functions grow unboundedly after sufficient number of de Sitter e-foldings, due to the appearances of secular logarithms. We focus on the purely local part of the vertex functions and attempt a resummation of them in terms of the dynamically generated mass of the scalar field at late times. Such local logarithms have sub-leading powers compared to the non-local leading ones which can be resummed via the stochastic formalism. The variation of these vertex functions are investigated with respect to the tree level couplings numerically. Since neither the secular effect, nor the dynamical generation of field mass is possible in the Minkowski spacetime, the above phenomenon has no flat spacetime analogue. We have also compared our result with the ones that could be found via the recently proposed renormalisation group techniques. All these results suggest that at late times the value of the non-perturbative vertex function should be less than the tree level coupling.

Density Functional Theory-Based Indicators to Estimate the Corrosion Potentials of Zinc Alloys in Chlorine-, Oxidizing-, and Sulfur-Harsh Environments.

Nowadays, biodegradable metals and alloys, as well as their corrosion behavior, are of particular interest. The corrosion process of metals and alloys under various harsh conditions can be studied via the investigation of corrosion atom adsorption on metal surfaces. This can be performed using density functional theory-based simulations. Importantly, comprehensive analytical data obtained in simulations including parameters such as adsorption energy, the amount of charge transferred, atomic coordinates, etc., can be utilized in machine learning models to predict corrosion behavior, adsorption ability, catalytic activity, etc., of metals and alloys. In this work, data on the corrosion indicators of Zn surfaces in Cl-, S-, and O-rich harsh environments are collected. A dataset containing adsorption height, adsorption energy, partial density of states, work function values, and electronic charges of individual atoms is presented. In addition, based on these corrosion descriptors, it is found that a Cl-rich environment is less harmful for different Zn surfaces compared to an O-rich environment, and more harmful compared to a S-rich environment.

Carrier mobility and broadband performance of two-dimensional Sb/SnSe van der Waals heterostructure: A first-principles study

Compared to single two-dimensional (2D) materials, stacking layered 2D materials with van der Waals (vdW) heterostructures offers novel opportunities to achieve desired exotic properties. Herein, 2D Sb/SnSe vdW heterostructure is constructed by vertically stacking the antimonene (Sb) monolayer on the tin selenide (SnSe) monolayer. We have conducted a theoretical study by using the first-principles calculations to comprehensively examine the electronic, optical, and mechanical properties. Phonon dispersion and ab initio molecular dynamics simulations have demonstrated that the Sb/SnSe vdW heterostructure possesses remarkable stability, ensuring its robustness up to 900 K. The Sb/SnSe vdW heterostructure is characterized as a semiconducting material with a direct band gap of 0.24 eV, calculated by the Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional method. Compared to the pristine Sb and SnSe monolayers, the Sb/SnSe vdW heterostructure exhibits a lower work function value of 3.82 eV. Furthermore, the carrier mobility of the heterostructure demonstrates anisotropic characteristics with a notable improvement in hole-mobility (12.05 × 103 cm2V−1s−1) along the y-direction. The Sb/SnSe vdW heterostructure shows enhanced broadband absorption spectra, especially in the visible to near-infrared ranges. Our findings underscore the potential of the Sb/SnSe vdW heterostructure for future nano-electronic and optoelectronic technologies.