Fundamental Relationships Research Articles

B-site substitution effects on the mechanical properties of halide perovskites [C4H12N2][BCl3]·H2O (B = NH4+; K+).

The mechanical properties of halide perovskites have been attracting ever-increasing interest for their significant importance in future industrial applications. However, studies focused on the effect of B-site substitution of molecular perovskites on their mechanical properties are rare, which makes it favorable to shed light on their fundamental structure-mechanical property relationships. Here, using isostructural halide perovskites, [C4H12N2][BCl3]·H2O (B = NH4+; K+), constructed by ionic bonds and hydrogen bonds, respectively, as the model systems, we investigate their mechanical properties through high-pressure synchrotron X-ray diffraction experiments and density functional theory calculations. Owing to the similar sizes of NH4+ and K+, the two compounds possess almost identical cell parameters and frameworks. Upon compression, the two perovskites exhibit analogous behavior except for slight differences in the shrinkage ratio of principal axes and the onset pressure of amorphization. The fitted bulk moduli of [C4H12N2][KCl3]·H2O and [C4H12N2][NH4Cl3]·H2O are 43.89 and 27.28 GPa, respectively. These results demonstrate that the simple replacement of K+ by NH4+ can significantly reduce the structural rigidity of the corresponding compounds, which is ascribed to the weaker strength of NH4⋯Cl hydrogen bonds than that of K-Cl bonds.

Spectroscopy-Guided Deep Learning Predicts Solid-Liquid Surface Adsorbate Properties in Unseen Solvents.

Accurately and rapidly acquiring the microscopic properties of a material is crucial for catalysis and electrochemistry. Characterization tools, such as spectroscopy, can be a valuable tool to infer these properties, and when combined with machine learning tools, they can theoretically achieve fast and accurate prediction results. However, on the path to practical applications, training a reliable machine learning model is faced with the challenge of uneven data distribution in a vast array of non-negligible solvent types. Herein, we employ a combination of the first-principles-based approach and data-driven model. Specifically, we utilize density functional theory (DFT) to calculate theoretical spectral data of CO-Ag adsorption in 23 different solvent systems as a data source. Subsequently, we propose a hierarchical knowledge extraction multiexpert neural network (HMNN) to bridge the knowledge gaps among different solvent systems. HMNN undergoes two training tiers: in tier I, it learns fundamental quantitative spectra-property relationships (QSPRs), and in tier II, it inherits the fundamental QSPR knowledge from previous steps through a dynamic integration of expert modules and subsequently captures the solvent differences. The results demonstrate HMNN's superiority in estimating a range of molecular adsorbate properties, with an error range of less than 0.008 eV for zero-shot predictions on unseen solvents. The findings underscore the usability, reliability, and convenience of HMNN and could pave the way for real-time access to microscopic properties by exploiting QSPR.

Home range overlap between small Indian mongooses and free roaming domestic dogs in Puerto Rico: implications for rabies management

The small Indian mongoose (Urva auropunctata) is the primary terrestrial wildlife rabies reservoir on at least four Caribbean islands, including Puerto Rico. In Puerto Rico, mongooses represent a risk to public health, based on direct human exposure and indirectly through the transmission of rabies virus to domestic animals. To date, the fundamental ecological relationships of space use among mongooses and between mongooses and domestic animals remain poorly understood. This study is the first to report mongoose home range estimates based on GPS telemetry, as well as concurrent space use among mongooses and free roaming domestic dogs (FRDD; Canis lupus familiaris). Mean (± SE) home range estimates from 19 mongooses in this study (145 ± 21 ha and 60 ± 14 ha for males and females, respectively) were greater than those reported in prior radiotelemetry studies in Puerto Rico. At the scale of their home range, mongooses preferentially used dry forest and shrubland areas, but tended to avoid brackish water vegetation, salt marshes, barren lands and developed areas. Home ranges from five FRDDs were highly variable in size (range 13–285 ha) and may be influenced by availability of reliable anthropogenic resources. Mongooses displayed high home range overlap (general overlap index, GOI = 82%). Home range overlap among mongooses and FRDDs was intermediate (GOI = 50%) and greater than home range overlap by FRDDs (GOI = 10%). Our results provide evidence that space use by both species presents opportunities for interspecific interaction and contact and suggests that human provisioning of dogs may play a role in limiting interactions between stray dogs and mongooses.

(Invited) Fundamental Structure-Function Relationships for Iridium Oxide Catalysts in PEM Water Electrolyzers

The intermittency of renewable energy poses significant challenges to developing a grid system that utilizes primarily renewable-based sources. Proton exchange membrane water electrolyzers (PEMWEs) can convert surplus energy from the grid into chemical energy in the form of green hydrogen, which can then be used to generate electricity when the renewable supply is low. Despite much technological advancement over the last two decades, PEMWEs still face many barriers to widespread commercialization. Around a quarter of the cost of the PEMWE system is attributed to iridium, a highly scarce material used as the oxygen evolution reaction (OER) catalyst on the anode side. To enable lower loadings/higher utilization of these catalysts, fundamental studies on iridium activity and degradation are necessary. As it stands in the literature, studies on how physical properties of the catalyst (i.e. crystallinities, valance states, etc.) affect PEMWE performance are scarce. This work aims to elucidate the relationship between structural properties and efficiency/performance for iridium oxide (IrOx ) catalysts in PEMWEs. Five commercially available iridium oxide catalysts were characterized (47491 Alfa Aesar, TEC77100, TEC77110, FIO-01, FIO-11) using transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET) analysis, and x-ray diffraction (XRD) to obtain crystallinities, particle size distributions, specific surface areas, thermal stabilities, elemental compositions, and valance states. Afterwards, kinetic performance was baselined by taking cyclic voltammograms (CVs) via rotating disk electrode (RDE) experiments and electrochemical surface areas (ECSA) were approximated by using a novel analysis developed in this work that can relate the hysteresis in OER potentials to a double layer capacity. Results show that greater amorphous character of IrOx was correlated with increased kinetic performance at the expense of electrochemical stability across redox potentials between 0-1.6V. From the cyclic voltammograms, the catalyst with the most amorphous character underwent multiple (two, possible three) redox transitions, while the one with the most crystalline character showed no evidence of any redox transitions. It was also found that increased ECSA was correlated with greater physical surface areas obtained from BET analysis and that greater amorphous character resulted in a higher Ir III :Ir IV ratio. For future work, we aim to incorporate these fundamental structure-function insights to create standardized accelerated stress tests for PEMWEs, as standards for durability testing have yet to be established.

A Data-Driven Approach to Molten Salt Synthesis of N-Rich Carbon Adsorbents for Selective CO2 Capture.

Applying a design of experiments methodology to the molten salt synthesis of nanoporous carbons enables inverse design and optimization of nitrogen (N)-rich carbon adsorbents with excellent CO2 /N2 selectivity and appreciable CO2 capacity for carbon capture via swing adsorption from dilute gas mixtures such as natural gas combined cycle flue gas. This data-driven study reveals fundamental structure-function relationships between the synthesis conditions, physicochemical properties, and achievable selective adsorption performance of N-rich nanoporous carbons derived from molten salt synthesis for CO2 capture. Taking advantage of size-sieving separation of CO2 (3.30 Å) from N2 (3.64 Å) within the turbostratic nanostructure of these N-rich carbons, while limiting deleterious N2 adsorption in a weaker adsorption site that harms selectivity, enables a large CO2 capacity (0.73mmol g-1 at 30.4Torr and 30 °C) with noteworthy concurrent CO2 /N2 selectivity as predicted by the ideal adsorbed solution theory(SIAST = 246) with an adsorbed phase purity of 91% from a simulated gas stream containing only 4% CO2 . Optimized N-rich porous carbons, with good physicochemical stability, low cost, and moderate regeneration energy, can achieve performance for selective CO2 adsorption that competes with other classes of advanced porous materials such as chemisorbing zeolites and functionalized metal-organic frameworks.

General relations for optical design parameters under diffraction limited paraxial imaging

We searched for fundamental relationships among general optical system parameters assuming diffraction limited imaging in paraxial space. We demonstrated that the total twelve optical system parameters describing the optical imaging problem are unambiguously determined with a set of four of them. This holds for a diffraction condition, where the image permitted blur is of the same size for both the spot due to defocus and the diffraction spot. Depending on the combinations of the four input parameters there can be found up to 314 different optical system design approaches to fully describe the diffraction limited imaging problem. We demonstrated eight examples of optical system design approaches using different combinations of input parameters. It can be helpful for optical designers to decide if diffraction limited imaging is feasible for the desired combination of optical imaging system parameters. With the reduction of the optical system to a thin lens approximation, the number of the optical system parameters describing the optical imaging problem decreases to eight and its unambiguous determination is possible with a set of only three of these parameters. It provides, up to 54 optical system design approaches based on different combinations of input parameters.

On basic arithmetic operations for interval-valued intuitionistic fuzzy sets using the Hamming distance with their application in decision making

Atanassov’s intuitionistic fuzzy sets play a vital role in handling vagueness and uncertainty successfully as they associate an additional non-membership degree to each element of the universal set. Interval-valued intuitionistic fuzzy (IVIF) sets are more generalized quantities in this direction as they use intervals (⊂[0,1]) to define the membership and non-membership grades of each element of the set. However, without defining basic arithmetic operations on the IVIF values/sets, the study is incomplete. This paper broadly examines the division and subtraction operations over any arbitrary IVIF values/sets using the concept of Hamming distance between them. A deterministic linear optimization model is proposed and solved in order to obtain the complete expressions for these operations. Next, various fundamental properties and relationships are examined and proved for the proposed arithmetic operations over IVIF values/sets. Furthermore, an example of a multi-criteria decision-making problem under uncertain conditions is studied and analyzed using the developed arithmetic operations on IVIF numbers.

The relationship between Myanmar’s past and its future

Outside Myanmar, the 2021 coup d’état has often been portrayed as the end of a hopeful period for the country. In this Adelphi book, however, Aaron Connelly and Shona Loong argue that the Aung San Suu Kyi government that preceded it was a false dawn, unlikely to fulfil the international community’s aspirations for a stable, peaceful and strong Myanmar. Instead, the movement opposing the 2021 coup holds much greater promise – despite the bloody conflict that dominates the news today. Connelly and Loong survey three fundamental relationships that have shaped Myanmar before and after the coup – between the military and the state, between the majority Burmese and ethnic minorities, and between Myanmar and the world – to explain how opposition to the coup has shifted all of them in a more liberal, pluralist and cosmopolitan direction.

The relationship between Myanmar and the world

Outside Myanmar, the 2021 coup d’état has often been portrayed as the end of a hopeful period for the country. In this Adelphi book, however, Aaron Connelly and Shona Loong argue that the Aung San Suu Kyi government that preceded it was a false dawn, unlikely to fulfil the international community’s aspirations for a stable, peaceful and strong Myanmar. Instead, the movement opposing the 2021 coup holds much greater promise – despite the bloody conflict that dominates the news today. Connelly and Loong survey three fundamental relationships that have shaped Myanmar before and after the coup – between the military and the state, between the majority Burmese and ethnic minorities, and between Myanmar and the world – to explain how opposition to the coup has shifted all of them in a more liberal, pluralist and cosmopolitan direction.

The relationship between the centre and the periphery

Outside Myanmar, the 2021 coup d’état has often been portrayed as the end of a hopeful period for the country. In this Adelphi book, however, Aaron Connelly and Shona Loong argue that the Aung San Suu Kyi government that preceded it was a false dawn, unlikely to fulfil the international community’s aspirations for a stable, peaceful and strong Myanmar. Instead, the movement opposing the 2021 coup holds much greater promise – despite the bloody conflict that dominates the news today. Connelly and Loong survey three fundamental relationships that have shaped Myanmar before and after the coup – between the military and the state, between the majority Burmese and ethnic minorities, and between Myanmar and the world – to explain how opposition to the coup has shifted all of them in a more liberal, pluralist and cosmopolitan direction.

The relationship between the armed forces and the state

Outside Myanmar, the 2021 coup d’état has often been portrayed as the end of a hopeful period for the country. In this Adelphi book, however, Aaron Connelly and Shona Loong argue that the Aung San Suu Kyi government that preceded it was a false dawn, unlikely to fulfil the international community’s aspirations for a stable, peaceful and strong Myanmar. Instead, the movement opposing the 2021 coup holds much greater promise – despite the bloody conflict that dominates the news today. Connelly and Loong survey three fundamental relationships that have shaped Myanmar before and after the coup – between the military and the state, between the majority Burmese and ethnic minorities, and between Myanmar and the world – to explain how opposition to the coup has shifted all of them in a more liberal, pluralist and cosmopolitan direction.

Introduction

Outside Myanmar, the 2021 coup d’état has often been portrayed as the end of a hopeful period for the country. In this Adelphi book, however, Aaron Connelly and Shona Loong argue that the Aung San Suu Kyi government that preceded it was a false dawn, unlikely to fulfil the international community’s aspirations for a stable, peaceful and strong Myanmar. Instead, the movement opposing the 2021 coup holds much greater promise – despite the bloody conflict that dominates the news today. Connelly and Loong survey three fundamental relationships that have shaped Myanmar before and after the coup – between the military and the state, between the majority Burmese and ethnic minorities, and between Myanmar and the world – to explain how opposition to the coup has shifted all of them in a more liberal, pluralist and cosmopolitan direction.

Intimacy, Passion, and Commitment in Supply Chain Relationships: Examining the Triangular Theory of Love

Purpose - This study empirically analyzes the impact of intimacy, passion, and commitment on information sharing and logistics performance within inter-company relationships in the supply chain.
 Design/Methodology/Approach - We adopted the triangular theory of love and established a research model on the assumption that these elements of human relationships—intimacy, passion, and commitment—lead to information sharing and improved logistics performance. To examine their correlations, a survey was administered among professionals in supply chain-related departments in South Korea. Subsequently, we tested hypotheses through structural equation modeling using SPSS 18.0 and AMOS 18.0.
 Findings - We found that all the components of the triangular theory of love—intimacy, passion, and commitment—significantly positively impacted information sharing. Moreover, we confirmed that information sharing significantly positively impacts logistics performance, which can represent supply chain performance.
 Research Implications - Based on these results, the following conclusions can be drawn: To form new business relationships and measure performance, fundamental human relationships between supply chain participants are crucial, as is the development of tools to quantitatively measure these relationships. For quantitative performance, information sharing based on human relationships is necessary. Therefore, as qualitative relationships and quantitative performance are increasing proportionally, supply chain participants must recognize their importance.

CONSEQUENCES OF THE COVID-19 PANDEMIC IN THE EUROPEAN UNION FROM THE PERSPECTIVE OF GENERAL GOVERNMENT FINANCES – AN ANALYSIS BASED ON THE SOCIAL ACCOUNTING MATRI

The aim of the paper is to assess the effects of the COVID-19 pandemic from the perspective of income circulation processes in the economies of the European Union. The empirical study is based on statistical data compiled according to ESA2010 standards, published by the European Commission in the Eurostat database. The fundamental quantitative relationships between entities grouped into institutional sectors have been synthetically presented in the form of a social accounting matrix (SAM). The analyses of simple macroeconomic indicators show the growing importance of the government sector due to the pandemic. This is evidenced by the growing involvement of this sector in consumption, accumulation and income redistribution between institutional sectors.Simulation analyses based on the SAM model determine to what extent the contribution of the government sector to GDP results directly through feedback loops from final demand and to what extent from current and capital transfers.

Positioning absorptive root respiration in the root economics space across woody and herbaceous species

Abstract1. Root respiration is essential for nutrient acquisition. The respiration rate of absorptive roots theoretically relates to the economics of carbon‐nutrient exchange, but its empirical role remains largely unexplored in the trait space defining nutrient uptake strategies.2. Here, we measured the respiration rates of the distal, non‐woody, absorptive roots of 252 woody and herbaceous species from subtropical and temperate climate zones, including both arbuscular mycorrhizal and ectomycorrhizal fungal hosts.3. We found a consistent and positive correlation between root respiration rate and specific root length (root length per dry weight), irrespective of growth form, mycorrhizal type and climate zone. Root respiration rate was also positively, but less strongly and less frequently correlated with root nitrogen concentration. Root morphology strongly explained the fast‐slow gradient of root respiration in the root economics space.4. By quantifying the ratio of arbuscular mycorrhizal fungal DNA copy number and root tissue DNA copy number using qPCR, we found that the morphology‐driven gradient did not explain the full variation in fungal collaboration; thick roots were consistently well colonised, but medium and thin roots displayed a wide range of colonisation intensity.5. Synthesis: These results advance our understanding of the fundamental trait relationships that underpin the root economics space. Our study also provides a physiological linkage to the frequently measured root morphological traits and relates the root economics space to root‐derived carbon‐nutrient cycling processes.

Comments on “Polymer compatibility,” Journal of Applied Polymer Science 17.10 (1973): 3175

AbstractThis concise note highlights certain errors, encompassing dimensional inconsistency and flaws in the expression of fundamental relationships, associated with Schneier's equation. This equation was initially published in the Journal of Applied Polymer Science [17.10 (1973): 3175] and has subsequently found application in consequent studies.

Evaluating the influence of cage motion on the growth and shell characteristics of oysters (Crassostrea virginica) among several gear types

An influx of new oyster culture gear provides growers with an expanded ability to grow oysters throughout the water column. Each gear type is exposed to a different regime of physical forces, which is thought to affect oyster production differently; however, there is a poor understanding of the physical conditions inside cages and how they influence the production rate and quality of oysters. A greater understanding of the fundamental relationships between cage motion, oyster growth, and shell shape could help to improve the efficiency of off-bottom oyster production. Such understanding is critical for tailoring gear selection and tuning gear performance to suit grower needs. To address this void, cage motion, internal oyster movement, and oyster growth among three common cultivation methods (Virginia-style bottom cages, Seapa® long-line baskets, and floating cages) were monitored over a single growing season to clarify the role of the physical environment on oyster performance (shell and tissue growth). The averages and variance in motion among each cultivation method were noticeably different, which resulted in significant differences in the growth rate and quality of oysters they produced. Movement of the floating cages and long-line baskets could largely be explained by wind waves generated from a single direction in the field (r2 = 0.49, r2 = 0.36, respectively), while bottom cage movement was far less affected by wind waves. The changes in physical conditions inside each cultivation method demonstrated a trade-off between shell growth rate (a metric of time to market) and shell and meat quality (representative of crop value). These results can help inform growers wishing to strategically adopt cultivation methods that are most aligned with their production goals.

Synthesis of a Bistable Recuperative Pump Powered by Shape Memory Alloys and a Two-Section Involute Cam

The paper discusses the synthesis problem of a bistable piston pump, employing a driving mechanism that comprises shape memory alloy wires, a two-section involute cam, and an energy-recuperating spring. The transition from one stable end position to another in the pump is achieved by heating and subsequently shortening one of the shape memory alloy wires, initiating the motion of the mechanism. This is then followed by the engagement of the recuperative spring to traverse the intermediate unstable equilibrium position and complete the entire stroke. The reversal of motion follows a similar approach, where the second SMA wire shortens while the first wire remains in a cold state. Importantly, the mechanism necessitates a low force within the shape memory alloy wire to initiate motion towards the opposite stable position. This research encompasses the examination of type, geometric, and force synthesis considerations for the pump, leading to the development of fundamental kinematic and force relationships. Moreover, a novel mechanism is proposed and synthesized, incorporating a two-section involute cam with a cusp point, to generate the desired discontinuous moment function produced by the recuperative spring. Further analysis reveals that the thermal time constant, which regulates the dynamic response of the mechanism, is directly proportional to the diameter of the driving SMA and inversely proportional to the square root of the number of SMA branches.

Fundamental scaling relationships revealed in the optical light curves of tidal disruption events

ABSTRACT We present fundamental scaling relationships between properties of the optical/UV light curves of tidal disruption events (TDEs) and the mass of the black hole that disrupted the star. We have uncovered these relations from the late-time emission of TDEs. Using a sample of 63 optically selected TDEs, the latest catalogue to date, we observed flattening of the early-time emission into a near-constant late-time plateau for at least two-thirds of our sources. Compared to other properties of the TDE light curves (e.g. peak luminosity or decay rate) the plateau luminosity shows the tightest correlation with the total mass of host galaxy (p-value of 2 × 10−6, with a residual scatter of 0.3 dex). Physically this plateau stems from the presence of an accretion flow. We demonstrate theoretically and numerically that the amplitude of this plateau emission is strongly correlated with black hole mass. By simulating a large population (N = 106) of TDEs, we determine a plateau luminosity-black hole mass scaling relationship well described by $\log _{10} \left({{M_{\bullet }}/M_\odot }\right) = 1.50 \log _{10} \left({ L_{\rm plat}}/10^{43} \, {\rm erg\, s^{-1}}\right) + 9.0$ (here Lplat is measured at 6 × 1014 Hz in the rest frame). The observed plateau luminosities of TDEs and black hole masses in our large sample are in excellent agreement with this simulation. Using the black hole mass predicted from the observed TDE plateau luminosity, we reproduce the well-known scaling relations between black hole mass and galaxy velocity dispersion. The large black hole masses of 10 of the TDEs in our sample allow us to provide constraints on their black hole spins, favouring rapidly rotating black holes. Finally, we also discover two significant correlations between early time properties of optical TDE light curves (the g-band peak luminosity and radiated energy) and the TDEs black hole mass.

Acetan-like heteropolysaccharide production by various Kozakia baliensis strains: Characterization and further insights

The family of Acetobacteraceae has demonstrated their ability to produce several heteropolysaccharides with a strong structural resemblance to xanthan gum. In this study, we assessed the potential of three isolates of K. baliensis as exopolysaccharide producers, namely K. baliensis SR-745, K. baliensis LMG 27018, and K. baliensis SR-1290. Among these, K. baliensis SR-745 was identified as the most promising candidate, exhibiting a final exopolysaccharide titer of 7.09 (± 0.50) g·L−1 and a productivity of 0.15 (± 0.01) g·L−1·h−1. Subsequent monomer analysis confirmed structural variations for the side chain composition of different strains. A molar subunit ratio of 6:1:1:1 (d-glucose: D-mannose: D-galactose: D-glucuronic acid) for EPS derived from K. baliensis SR-745 and of 3:1:3:1 for K. baliensis LMG 27018 was determined, while the exopolysaccharide produced by K. baliensis SR-1290 consisted of a major share of rhamnose. In-depth rheological polymer characterizations revealed high viscosity rates and predominantly elastic gel character, making polysaccharides of K. baliensis highly interesting for applications in the food and cosmetic industry. Further insights into the fundamental structure-function relationships of biopolymers were obtained by comparing exopolysaccharides derived from K. baliensis to a genetically engineered xanthan variant lacking acetyl and pyruvyl substitutions.