State Theory Research Articles

The Influence of Communication Strategy on User Satisfaction at the Medan State Polytechnic Library

The title of this research was The Influence of Communication Strategy and Prime Service on Library Members’ Satisfaction at the Library of Politeknik Negeri Medan. The research used the theory of satisfaction. Kotler (2014) points out that there are two theories of satisfaction: theory of performance expectation and theory of cognitive inappropriateness. Theory of performance expectation states that consumer satisfaction is the function of consumers’ expectation of the result. If the result is in accordance with what has been expected, consumers will be satisfied, if it exceeds what has been expected, they will be more satisfied, but if it is not in accordance with what has been expected, they will be dissatisfied. The population was 5,994 members of the library, and 98 of them were used as the samples, taken by using Slovin formula. The data were gathered by using questionnaires and conducting documentation and observation. The result of the research showed that the factors of communication strategy and prime service had positive and significant influence on library members’ satisfaction which indicated that the better the communication strategy and the prime service, the higher the library members’ level of satisfaction.

Is Trusting Your Gut a Good Idea? Implications from The Emotional Mind

What exactly does it mean to “trust your gut”? What use are gut-level insights when a person is attempting to consciously and deliberately navigate life altering decisions, such as those surrounding marriage, divorce, job changes, home buying, etc.? This essay provides a partial answer to those questions by leveraging the account of “emotional bodily feelings” offered in Tom Cochrane’s The Emotional Mind: A Control Theory of Affective States. This essay shows why “trusting your gut” is a reasonably good path to emotional self-awareness in decision-making. The first half of the essay offers an analysis of what many people mean by the colloquial advice to “trust your gut,” at least when they deploy that advice in context of an ongoing dialogue about a friend or family member’s major life-decision. In the second half, this article briefly summarizes Cochrane’s account of emotions and emotional bodily feelings, and spells out how these concepts might be deployed to understand the advice to “trust your gut” as nearly tantamount to saying “pursue emotional self-awareness.”

Density and viscosity modeling of liquid adipates using neural network approaches

Liquid Dialkylesters of adipic acid (adipates) have achieved prominence as alternative green solvents due to their special properties. To enhance their utilization, accurate thermophysical property data are required, especially for extended pressure ranges. This study presents the application of Artificial Neural Networks (ANNs) for predicting the densities and viscosities of liquid adipates over a wide range of temperatures and pressures. A substantial dataset, including 1145 viscosity and 891 density data points, was utilized across a broad range of temperature and pressure conditions. The dataset used for densities includes data for six different liquid adipates and covers a temperature range of 293.15–403.15 K and pressures up to 140 MPa, while the dataset used for viscosities encompasses data for four different liquid adipates, ranging from 293.15 K to 403.15 K in temperature and up to 65.62 MPa in pressure. Two ANN models were developed and fine-tuned, with two separate models created to predict the properties of liquid adipates. These models exhibited very good performance, achieving an Average Absolute Relative Deviation (AARD) of 0.028 % for density and 0.400 % for viscosity. The results from the ANN models were compared with semi-empirical models based on the equation of state and rough hard-sphere theory, showcasing the technique's potential as a powerful tool for characterizing thermophysical properties. As part of enhancing model reliability and robustness, various tests were conducted to validate the chosen model.

Harmonic transition state theory applied to vacancy diffusion pre-exponential factors in a concentrated solid-solution alloy

Harmonic transition state theory applied to vacancy diffusion pre-exponential factors in a concentrated solid-solution alloy

A novel method for predicting the thermal stabilization temperature of organic Rankine cycle system working fluids based on transition state theory

The use of organic working fluids in organic Rankine cycle (ORC) systems may lead to thermal decomposition, which negatively impacts system performance and safety. In this work, a simplified theoretical method based on the transition state theory is proposed to predict the ideal maximum thermal stabilization temperature of organic working fluids. This method involves considering the initial decomposition reaction of the working fluids and calculating the total reaction rate of the initial decomposition. By setting an acceptable decomposition rate, the ideal maximum thermal stabilization temperature of the working fluid can be determined. Using this method, the total reaction rate constants of several typical hydrocarbon, hydrofluorocarbon and siloxane working fluids were obtained in the temperature range of 300∼700 K. The predicted maximum operational temperatures were in good agreement with most experimental results. The branch ratio analyses show that C–C bond cleavage contributed mainly to the decomposition of hydrocarbons, the removal of HF and C–C bond cleavage contributed mainly to that of HFCs, and the Si–C bond cleavage contributed mainly to that of siloxanes. Only considering these main reactions in the reaction rate calculation can greatly reduce calculation cost without significantly impacting the prediction accuracy.

Fast crystal growth in deeply undercooled ZrTi melts.

We investigate the growth of crystals in Zr50Ti50 melts by classical molecular-dynamics simulations with an embedded atom method and a Stillinger-Weber potential model. Both models display fast solidification rates that can be captured by the transition state theory or the Ginzburg-Landau theory at small undercoolings. Fast crystal-growth rates are found to be affected by the pre-existing ordering in liquids, such as the body-centered cubic-like and icosahedral-like structures. The interface-induced ordering unveiled by the crystal-freezing method can explain the rate difference between these two models. However, these orderings fail to rationalize the temperature evolution of the growth rate at deep undercoolings. We correlate the growth kinetics with the detailed dynamical processes in liquids, finding the decoupling of hierarchic relaxation processes when collective motion emerges in supercooled liquids. We find that the growth kinetics is nondiffusive, but with a lower activation barrier corresponding to the structural relaxation or the cage-relative motion in ZrTi melts. These results explore a new relaxation mechanism for the fast growth rate in deeply undercooled liquids.

Rapid Atmospheric Reactions between Criegee Intermediates and Hypochlorous Acid.

Hypochlorous acid (HOCl) is a paramount compound in the atmosphere due to its significant contribution to both tropospheric oxidation capacity and ozone depletion. The main removal routes for HOCl are photolysis and the reaction with OH during the daytime, while these processes are unimportant during the nighttime. Here, we report the rapid reactions of Criegee intermediates (CH2OO and anti/syn-CH3CHOO) with HOCl by using high-level quantum chemical methods as the benchmark; their accuracy is close to coupled cluster theory with single, double, and triple excitations and quasiperturbative connected quadruple excitations with a complete basis limit by extrapolation [CCSDT(Q)/CBS]. Their rate constants have been calculated by using a dual-level strategy; this combines conventional transition state theory calculated at the benchmark level with variational transition state theory with small-curvature tunneling by a validated density functional method. We find that the introduction of the methyl group into Criegee intermediates not only affects their reactivities but also exerts a remarkable influence on anharmonicity. The calculated results uncover that anharmonicity increases the rate constants of CH2OO + HOCl by a factor of 18-5, while it is of minor importance in the anti/syn-CH3CHOO + HOCl reaction at 190-350 K. The present findings reveal that the loose transition state for anti-CH3CHOO and HOCl is a rate-determining step at 190-350 K. We also find that the reaction of Criegee intermediates with HOCl contributes significantly to the sink of HOCl during the nighttime in the atmosphere.

Theoretical Study of the NO Reduction Mechanism on Biochar Surfaces Modified by Li and Na Single Adsorption and OH Co-Adsorption

Theoretical and experimental investigations have shown that biochar, following KOH activation, enhances the efficiency of NO removal. Similarly, NaOH activation also improves NO removal efficiency, although the underlying mechanism remains unclear. In this study, zigzag configurations were employed as biochar models. Density functional theory (DFT) was utilized to examine how Li and Na single adsorption and OH co-adsorption affect the reaction pathways of NO reduction on the biochar surface. The rate constants for all reaction-determining steps (RDSs) within a temperature range of 200 to 1000 K were calculated using conventional transition state theory (TST). The results indicate a decrease in the activation energy for NO reduction reactions on biochar when activated by Li and Na adsorption, thus highlighting their beneficial role in NO reduction. Compared to the case with Na activation, Li-activated biochar exhibited superior performance in terms of the NO elimination rate. Furthermore, upon the adsorption of the OH functional group onto the Li-decorated and Na-decorated biochar models (LiOH-decorated and NaOH-decorated chars), the RDS energy barriers were higher than those of Li and Na single adsorption but easily overcome, suggesting effective NO reduction. In conclusion, Li-decorated biochar showed the highest reactivity due to its low RDS barrier and exothermic reaction on the surface.

State autonomy, economic reform & business elite influence in the GCC

ABSTRACT This study challenges traditional rentier state theory and contributes to a new generation of scholarship focused on state-business relations by evaluating the relationship between different degrees of state policymaking autonomy and business elite influences in political and economic institutions. The findings of this study address central policy questions about economic reform in the Gulf Cooperation Council countries. Using primary data from my case studies of Qatar and Kuwait, I posit two arguments. First, states with lesser business elite influence over political institutions have more autonomy to realise their economic reform goals; a less dominant and influential business elite circle will more likely submit to state-led economic reform initiatives. Greater business elite dominance, meanwhile, tends to create a powerful bloc undercutting economic change, such as labour reform or new regulatory frameworks, that would benefit the long-term stability of the state. Second, rentier states with higher degrees of state-led capitalism have more autonomy to conduct economic reforms; state-led capitalism produces more coherent and cohesive state apparatuses that can incentivize business elite cooperation.

Investigation on the yield and failure criterion of foamed concrete

This study systematically investigated the yielding and failure criterions of foamed concrete through the proposed control equations. Firstly, four loading-path experiments including uniaxial tension, uniaxial compression, triaxial shear, and isotropic compression were conducted to comprehensively analyze the mechanical behaviour of foamed concretes. The results indicated that foamed concretes experienced elastic stage, softening or hardening stage, and strength stability stage subjected to the uniaxial loading. During the loading process, some cemented binders within foamed concretes would be broken into particles and then moved to fill the internal pores. Afterwards, the failure criterion of foamed concretes was explicated based on the critical state theory, where two control equations regarding stress and deformation aspects were proposed. Finally, a yield function containing tension, compression, and shear loading paths was proposed to describe the yielding performance of foamed concretes. Compared with the experiment data, the prediction accuracy of the proposed yield function has reached more than 95 %. This research provides theorical basis for the practical application of foamed concretes.

High-Pressure Limit and Pressure-Dependent Rate Rules for β-Scission Reaction Class of Hydroperoxyl Alkyl Hydroperoxyl Radicals (•P(OOH)2) in Normal-Alkyl Cyclohexanes Combustion.

Chemical kinetic studies of the β-scission reaction class of hydroperoxyl alkyl hydroperoxyl radicals (•P(OOH)2) from normal-alkyl cyclohexanes are carried out systematically through high-level ab initio calculations. Geometry optimizations and frequency calculations for all species involved in the reactions are performed at the B3LYP/CBSB7 level of theory. Electronic single-point energy calculations are calculated at the CBS-QB3 level of theory. Rate constants for the reactions of β-scission, in the temperature range of 500-1500 K and the pressure range of 0.01-100 atm, are calculated using transition state theory (TST) and Rice-Ramsberger-Kassel-Marcus/Master-Equation (RRKM/ME) theory taking asymmetric Eckart tunneling corrections and the one-dimensional hindered rotor approximation into consideration. The rate rules are obtained by averaging the rate constants of the representative reactions of this class. These rate rules can greatly assist in constructing more accurate low-temperature combustion mechanisms for normal-alkyl cyclohexanes.

Group contribution method for rapid estimation of crystal growth rates

The morphological evolution of organic crystals during crystallization depends on the face-specific growth rates. Classical growth rate models relate the face-specific growth rates to the crystal lattice, energy of stable facets, growth mechanism, and supersaturation. The complexities of these models have increased over time to account accurately for solution conditions, the structure of growth units, and their attachment rates. Such advanced growth rate models require several layers of computations to obtain attachment energies of facets, nucleation rates, kink density, and attachment rates. Among these, the most intensive and time-consuming computation is for attachment rates, which require molecular dynamic simulations. This substantially increases the overall computation time to predict the absolute growth rate for even one crystallization condition. Since it is nearly impossible to iterate such a growth rate model, optimization schemes cannot be implemented to identify solution conditions that favor specific crystal growth. To reduce the computational time for attachment rate calculations, we implement a group contribution method (GCM) that relates the properties of functional groups in a molecule to their attachment rates to the crystal lattice, thereby rapidly estimating the growth rates of organic crystals. The process of molecular attachment involves partial desolvation of a solvated molecule, referred to as a transition state, followed by total desolvation via spontaneous attachment to a crystal facet. The first step in GCM is to identify the equilibrium states of fully solvated and partially desolvated solute molecules. The degree of supersaturation dictates the extent of this equilibrium and, thereby, the activation barrier for the growth of crystals, according to transition state theory. Identifying this equilibrium phenomenon allows for capturing the functional-group-specific interactions that depend on molecular motion, which could be related to operating conditions such as temperature and pressure. The stochastic optimization technique with Monte-Carlo sampling allows an efficient optimization problem solution to obtain the group interaction parameters. The GCM approach is first validated for the estimation of growth rates of glutamic acid and L-histidine, and then extended to predict growth rates of alanine and glycine rapidly. The optimized parameters and GCM scheme can be used to estimate growth rates in other crystallization systems.

A theoretical and experimental study of 2-ethylfuran + OH reaction

2-Ethylfuran (EF2), having similar thermophysical properties as gasoline, can be produced from biomass and has received increasing attention in recent years. The reaction of EF2 with OH radical plays a fundamental role in combustion chemistry of furan fuels. This work provides a comprehensive investigation on the reaction kinetics of the title reaction. The performance of several density functional theory methods is evaluated against the DLPNOCCSD(T)/CBS(T-Q) benchmark method. The results show that M08-HX/jun-cc-pVTZ is the best one for both abstraction and addition reactions with the lowest average unsigned deviations of 0.61 and 0.63 kcal mol−1, respectively. Multi-structural variational transition state theory combined with small-curvature tunneling approximation (MS-CVT/SCT) is employed to calculate the high-pressure limit (HPL) rate constants over a wide temperature range of 500−2000 K. The system-specific quantum Rice-Ramsperger-Kassel (SS-QRRK) method is used to obtain the pressure-dependent rate constants for addition reactions at several selected pressures from 0.01 to 100 atm. We have measured the rate constants of EF2 + OH reaction behind reflected shock wave at temperatures of 985−1342 K and pressure around 1 bar. The measured rate constants exhibit a positive temperature dependence and may be described by a three-parameter Arrhenius expression: k=1.28×10−10×T6.89exp(5318T) (cm3 mol−1 s–1). The calculated results are in good agreement with measurements and the total rate constants exhibit a non-monotonic temperature dependence due to the competition between the abstraction and addition channels. At the HPL, the addition reaction is dominant, and the branching ratio is larger than abstraction reaction at 500–1800 K and is 0.92 at 500 K. Finally, to evaluate the performance of our calculations on the ignition delay time of EF2, three available kinetic models (Somers et al., Xu et al. and Li et al.) of EF2 are updated and the results show that the predictions of Li's model are improved.

Coverage-dependent desorption kinetics of water on a well-ordered alumina thin film surface.

We have developed an experimental and analytical setup for thermal desorption spectroscopy of solid water films on surfaces. We obtain the coverage-dependent desorption kinetics of water molecules from a well-defined ultra-thin alumina/NiAl(110) surface in the coverage range of 0-2 monolayers. We use a novel deconvolution technique to eliminate the pumping delay of water vapor in the vacuum system, which has previously hindered the accurate estimation of desorption kinetic parameters, such as activation energy and pre-exponential factor. The coverage-dependent Arrhenius analysis reveals that the desorption activation energy decreases with increasing coverage in the sub-monolayer range, indicating that the water-water interaction is not attractive. We also find that the pre-exponential factor for the second layer is higher than that for the sub-monolayer. We explain this difference in terms of transition state theory and propose that entropic effects play a significant role in water desorption kinetics.

The local rupture of the superconductivity and the curvature of the mesoscopic sample

In this article we revisit a well-known effect in superconductors, which is the penetration of the magnetic field by regions of greater radius of curvature (Tinkham, 2008; De Gennes, 1966). This is exposed in the literature but without a quantitative solution. Here we solve this problem by two distinct numerical simulations. We calculate the superconducting current density using numerical simulations via the London theory in the Meissner state and numerical simulations using the time-dependent Ginzburg–Landau (TDGL) theory for the vortex state. In both simulations, the results obtained are in agreement, as could not be otherwise. We show that in the Meissner state the current density increases much faster in the region where the radius of curvature is larger, thus reaching the critical value first in this location, and therefore local breakdown of superconductivity occurs. In the vortex state, our simulations, using TDGL, show that the vortices penetrate through exactly the same location pointed out by the previous simulation. For this study we worked with a superconducting needle with an ellipsoidal mesoscopic cross section.

Theoretical kinetic study of key reactions between ammonia and fuel molecules, part I: Hydrogen atom abstraction from alkanes by ṄH2 radical

Cross reactions between ṄH2 radical and fuel molecules are essential in determining the reactivity for ammonia/fuel blends. A systematic theoretical chemical kinetic investigation of hydrogen atom abstraction by ṄH2 radical from C1–C6 alkanes, n-heptane, and isooctane has been performed in this study. The geometry optimization, frequency, and zero-point energy calculations for all species related to the title reactions were calculated at the M06-2X/6-311++G(d,p) level of theory. One-dimensional hindered rotor treatment has also been performed at the same level of theory to obtain the potential energy surface for the low frequency torsional modes. Single-point energy was obtained at the QCISD(T)/cc-pVDZ, QCISD(T)/cc-pVTZ, MP2/cc-pVDZ, MP2/cc-pVTZ and MP2/cc-pVQZ levels of theory and then extrapolated to the complete basis set. Benchmark calculations for single point energy have also been carried out at the CCSD(T)-F12/cc-pVTZ, CCSD(T)-F12/cc-pVQZ, CCSD(T)-F12/aug-cc-pVTZ and CCSD(T)-F12/aug-cc-pVQZ levels of theory based on the geometries obtained at the CCSD(T)/cc-pVDZ level of theory for the reaction systems of methane + ṄH2 and ethane + ṄH2. The rate constants of 41 reactions in the temperature range 298.15–2000 K were calculated by using the Master Equation System Solver (MESS) with conventional transition state theory. Good agreement has been gained between our calculated results and the available theoretical and experimental data in the literature. Rate rules for different reaction sites have also been derived, and the average rate constants for primary, secondary, and tertiary sites were also reported on a per hydrogen atom basis. The impact of calculation data for the ammonia/alkane blends model has also been investigated. The calculated rate constants are valuable for the combustion kinetic model development for ammonia blending fuels.

Theoretical study on iso‐pentanol oxidation chemistry: Fuel radical isomerization and decomposition kinetics and mechanism development

AbstractThis study undertakes a detailed theoretical investigation into the iso‐pentanol radical isomerization and decomposition kinetics and the mechanism development of the iso‐pentanol oxidation. The CCSD(T)/CBS//M08‐HX/6‐311+G(2df,2p) method was adopted to calculate the reaction potential energy surface. The reaction rate coefficients were calculated by variational transition state theory (VTST) with multistructural torsional (MS‐T) partition function and small curvature tunneling (SCT) correction. Moreover, the pressure‐dependent rate coefficients were determined using the system‐specific quantum Rice‐Ramsperger‐Kassel theory (SS‐QRRK). The variational and tunneling effects were discussed, and the dominant reaction channels were identified. It reveals that the isomerization reactions play a significant role at low temperatures, while the decomposition reactions dominate the high‐temperature regime. Notably, the quantitative rate expressions for iso‐pentanol radical decomposition reactions were also obtained. Furthermore, a new kinetic model incorporating the calculated rate coefficients was constructed, exhibiting satisfactory prediction performance on ignition delay times and improved predictive accuracy of species mole fractions. This work provides accurate rate data of isomerization and decomposition kinetics and contributes to a more comprehensive understanding of the iso‐pentanol oxidation mechanism.

Bolzano on aesthetic normativity

Abstract A theory of aesthetic normativity states what makes it the case that the fact that an item is beautiful is reason to appreciate it. Aesthetic hedonists characteristically hold that the fact that an item is beautiful is reason to appreciate it because anyone always has reason to do what yields pleasure. Bernard Bolzano was an aesthetic hedonist who is best interpreted as offering a mixed theory of aesthetic normativity.The fact that an item is beautiful is reason to appreciate it because anyone always has reason to do what yields pleasure and because anyone also has reason to do what fosters virtue, the capacity to act well. The argument for this interpretation knits together Bolzano’s aesthetics, his ethics, and his philosophy of science. In doing so, this argument opens up a new perspective on aesthetic normativity.

The Popularity Gap: Effects of Social Status on the Visibility of Lifestyle Sports Stars on Instagram

Social media provides athletes with opportunities to enhance their personal brands, engage with fans, and access professional opportunities. Several studies have examined how athletes use social media to attract and engage large audiences. Less is known about the social forces that enable and constrain their popularity. Drawing on expectation states theory, this study considers how athletes’ social status affects their follower counts and engagement rates on Instagram. Based on a content analysis of 6240 images posted on Instagram by 112 professional disc golfers, we show that the gender, sport dominance, and physical attractiveness of athletes affect their popularity, controlling for their strategic efforts to self-brand. These findings offer new insight into the ongoing debate over social media’s impact on long-standing inequalities in the media-sport industry.

Affixing the Nomads: Revisiting Marx’s Theory of “So-Called Primitive Accumulation” with a Deleuzo-Guattarian-Inspired Theory of the Colonial State

This essay tests Karl Marx’s theory of primitive accumulation on nomadic and seminomadic populations. Drawing on a comparative historical-sociological analysis of nomadic communities in North Africa and North America, it argues that in primitive accumulation, the control of mobility is as central as that of land enclosure. It theorizes the role of the colonial state as an apparatus of capture that operates not only through enclosure but through processes of deterritorialization and reterritorialization. For the colonized, this historical and continuous process of primitive accumulation operates through a double enclosure: land and mobility. For the empire, this process consolidates imperialism and statehood. Primitive accumulation deployed by a colonial state is empire making. This essay thus agrees with indigenous and critical scholars about the race-making function of primitive accumulation and provides a theoretical foundation regarding the primitive accumulation of mobility relevant to—but occulted by—the field of the sociology of migration.