Shape Of Potential Research Articles

Economic spillovers and political payoffs in government competition for firms: Evidence from the Kansas City Border War

When jurisdictions use business incentives to compete for firms, the political payoffs of winning firms are privately derived by the politicians of the winning jurisdictions, but the economic payoffs, such as new jobs, can spill over to the residents of non-winning jurisdictions. I study how potential political payoffs shape government competition for firms using a simple model of government competition and firm location choice. I use the model to propose an empirical approach of deriving lower bounds on political payoffs with data on accepted incentives. Applying this approach to the recent state competition between Kansas and Missouri for firm relocation within Kansas City, I find that the two states derived sizable political payoffs.

Universality of Internal Correlations of Strongly Interacting p -Wave Fermions in One-Dimensional Geometry

We consider the many-body ground state of polarized fermions interacting via zero-range $p$-wave forces in a one-dimensional geometry. We rigorously prove that in the limit of infinite attractions spectral properties of any-order reduced density matrix describing arbitrary subsystem are completely independent of the shape of an external potential. It means that quantum correlations between any two subsystems are in this limit insensitive to the confinement. In addition, we show that the purity of these matrices quantifying the amount of quantum correlations can be obtained analytically for any number of particles without diagonalizing them. This observation may serve as a rigorous benchmark for other models and methods describing strongly interacting $p$-wave fermions.

Cross-linguistic influence meets diminished input: A comparative study of heritage Russian in contact with Hebrew and English

While it is known that heritage speakers diverge from the homeland baseline, there is still no consensus on the mechanisms triggering this divergence. We investigate the impact of two potential factors shaping adult heritage language (HL) grammars: (1) cross-linguistic influence (CLI), originally proposed for second language acquisition (SLA), and (2) background factors associated with input. To assess the role of CLI and input we compared two groups of adult heritage speakers of Russian ( n = 66) with two typologically distinct societal languages (SLs), Hebrew and American English. Their production was evaluated for three morphosyntactic phenomena: adjective–noun agreement, accusative case morphology, and numerical phrases. Using self-rating and baseline vocabulary tasks as proficiency measures, we conducted controlled experiments to assess mastery of the target phenomena. Our results show that, while CLI is the main mechanism behind HL grammar maintenance, increased input and proficiency can modulate performance in the absence of grammatical similarities between the HL and SL. An analysis of non-target responses revealed systematic patterns, including reliance on default, or unmarked, forms in both groups, in line with previous research. These findings contribute to the literature on the mechanisms of HL grammar formation and maintenance.

Market Analysis for “Naga Minerals “ and It Competitions Over National and Regional Brands

This market analysis aims to investigate the competitive landscape of “Naga Minerals” and its position against national and regional brands in the market. The study encompasses a comprehensive examination of the mineral industry, focusing on the company’s products, market share, and key competitors. By conducting an in-depth analysis, this research seeks to provide valuable insights into the market dynamics, customer preferences, and strategies employed by “Naga Minerals” and its competitors. The analysis begins by delving into the mineral industry’s overview, including market size, growth potential, and key drivers shaping the sector. It then narrows down to explore the specific product portfolio of “Naga Minerals,” emphasizing its unique selling propositions and target market segments. Through a thorough examination of industry data, customer feedback, and market trends, the study assesses the company’s market position and competitiveness.

Minimal conditions for solidification and thermal processing of colloidal gels

Colloidal gelation is used to form processable soft solids from a wide range of functional materials. Although multiple gelation routes are known to create gels of different types, the microscopic processes during gelation that differentiate them remain murky. A fundamental question is how the thermodynamic quench influences the microscopic driving forces of gelation, and determines the threshold or minimal conditions where gels form. We present a method that predicts these conditions on a colloidal phase diagram, and mechanistically connects the quench path of attractive and thermal forces to the emergence of gelled states. Our method employs systematically varied quenches of a colloidal fluid over a range of volume fractions to identify minimal conditions for gel solidification. The method is applied to experimental and simulated systems to test its generality toward attractions with varied shapes. Using structural and rheological characterization, we show that all gels incorporate elements of percolation, phase separation, and glassy arrest, where the quench path sets their interplay and determines the shape of the gelation boundary. We find that the slope of the gelation boundary corresponds to the dominant gelation mechanism, and its location approximately scales with the equilibrium fluid critical point. These results are insensitive to potential shape, suggesting that this interplay of mechanisms is applicable to a wide range of colloidal systems. By resolving regions of the phase diagram where this interplay evolves in time, we elucidate how programmed quenches to the gelled state could be used to effectively tailor gel structure and mechanics.

Characteristic curves of the Mie fluid

Brown's characteristic curves of the Mie n,m fluid were investigated using molecular dynamics (MD) simulation and a molecular-based equation of state. Both, the 0th-order (Zeno) and three 1st-order characteristic curves (Amagat, Boyle, and Charles) were studied. The study was carried out using a hybrid approach combining MD simulation and molecular theory. Thereby, exact values for the zero-density limit of the characteristic curves were obtained using the second virial coefficient route. The focus was on the variation of the repulsive exponent of the Mie potential with n=8,10,11,12,13,14,16,20,36,48 (dispersive exponent constant at m=6). Also, the influence of the dispersive exponent on the characteristic curves was studied with m=4,5,6,7,8 (repulsive exponent constant at n=12). In total, 14 Mie fluids were studied. Based on the results, the influence of the shape of the intermolecular potential on the macroscopic properties, i.e. the characteristic curves, is elucidated. Interestingly, the Amagat curve is found to exhibit a peculiar dependency on the repulsive exponent. However, the postulates of Brown regarding the form and regularities of the characteristic curves are confirmed for all studied Mie fluids. Furthermore, the applicability of the classical corresponding states principle is assessed using the characteristic curve data. Important differences are obtained for the two exponents: The corresponding states principle captures reasonably well the variation of the dispersive exponent, but fails for describing the influence of the repulsive exponent. The results from this work are compared with predictions from a molecular-based equation of state, which is found to perform well in almost all studied cases.

Energy shaping control of a class of underactuated mechanical systems with high-order actuator dynamics

In this work we present some new results on energy shaping control for underactuated mechanical systems with high-order actuator dynamics. To this end, we propose an extension of the Interconnection and damping assignment Passivity based control methodology to account for actuator dynamics. This brings the following new results: i) a potential and kinetic energy shaping and damping assignment procedure that yields two alternative controllers; ii) a potential energy shaping and damping assignment procedure for a narrower class of underactuated mechanical systems. The proposed approach is illustrated with numerical simulations on three examples: an Acrobot system with a series elastic actuator; a soft continuum manipulator actuated by electroactive polymers; a two-mass-spring system actuated by a DC motor.

Inflation with very small tensor-to-scalar ratio

We have investigated inflation models that predict a very small value of the tensor-to-scalar ratio, $r$ . The spectral index $n_{s}$ , and the tensor-to-scalar ratio $r$ , are strictly constrained by the Planck data. $n_{s}$ and $r$ are sensitive to the shape and magnitude of the inflaton potential, respectively. The constraints by the Planck 2018 data combined with other cosmological observations are compared with the predictions from the inflation models regarding $n_{s}$ and $r$ . Furthermore, we discuss the comparison of future tensor-to-scalar ratio data with predictions from the inflation models with a focus on part of the quantum fluctuation origin.

Influence of catalyst pelletization on propane dehydrogenation over hierarchical MFI zeolite supported with platinum-yttrium nanoparticles

Platinum-yttrium (PtY) nanoparticles supported on a siliceous form of mesoporous MFI zeolite (MZ) were recently found to exhibit excellent catalytic performance in propane dehydrogenation (PDH). Herein, potential shaping of the PtY/MZ catalyst is investigated from the laboratory-synthesized powder form into industrially preferable pellets. The MZ zeolite powder was synthesized using multi-ammonium surfactants as a structure-directing agent and then pelletized in a hydraulic press by itself or with inorganic binders (i.e., pseudoboehmite, fumed silica, or hydrotalcite). As a part of the sequential pelletization process, pressing was followed by a high-temperature treatment (923 K). Addition of 20 wt% pseudoboehmite resulted in the highest mechanical strength without a significant loss of the initial zeolite mesoporosity. The pseudoboehmite-bound pellet also showed high catalytic activity and longevity in PDH application when simultaneously impregnated with 1 wt% Pt [Pt(NH3)4(NO3)2] and 1 wt% Y [Y(NO3)2·6H2O]. Notwithstanding the observed high propane conversion, the pseudoboehmite-bound catalyst produced an unsatisfactory result of low propylene selectivity (∼60%). Image analyses of HAADF-STEM EDS and solid-state 31P NMR spectroscopic data suggest that such findings could be attributed to Al migration from pseudoboehmite onto zeolite regime during the phase transformation of pseudoboehmite in the shaping process. Alternatively, the uses of non-acidic binders, such as fumed silica and hydrotalcite binders were also demonstrated. The silica-bound catalyst yielded high propane conversion with high propylene selectivity although mechanical strengths of the pellet were compromised to a moderate level.

Are All Patients Going Home after Total Knee Arthroplasty? A Temporal Analysis of Discharge Trends and Predictors of Nonhome Discharge (2011-2020).

Value-based orthopaedic surgery and reimbursement changes for total knee arthroplasty (TKA) are potential factors shaping arthroplasty practice nationwide. This study aimed to evaluate (1) trends in discharge disposition (home vs nonhome discharge), (2) episode-of-care outcomes for home and nonhome discharge cohorts, and (3) predictors of nonhome discharge among patients undergoing TKA from 2011 to 2020. The National Surgical Quality Improvement Program database was reviewed for all primary TKAs from 2011 to 2020. A total of 462,858 patients were identified and grouped into home discharge (n = 378,771) and nonhome discharge (n = 84,087) cohorts. The primary outcome was the annual rate of home/nonhome discharges. Secondary outcomes included trends in health care utilization parameters, readmissions, and complications. Multivariable logistic regression analyses were performed to evaluate factors associated with nonhome discharge. Overall, 82% were discharged home, and 18% were discharged to a nonhome facility. Home discharge rates increased from 65.5% in 2011 to 94% in 2020. Nonhome discharge rates decreased from 34.5% in 2011 to 6% in 2020. Thirty-day readmissions decreased from 3.2 to 2.4% for the home discharge cohort but increased from 5.6 to 6.1% for the nonhome discharge cohort. Female sex, Asian or Black race, Hispanic ethnicity, American Society of Anesthesiology (ASA) class > II, Charlson comorbidity index scores > 0, smoking, dependent functional status, and age > 60 years were associated with higher odds of nonhome discharge. Over the last decade, there has been a major shift to home discharge after TKA. Future work is needed to further assess if perioperative interventions may have a positive effect in decreasing adverse outcomes in nonhome discharge patients.

Mass renormalization in lattice simulations of false vacuum decay

False vacuum decay, a quantum mechanical first-order phase transition in scalar field theories, is an important phenomenon in early Universe cosmology. Recently, real-time semiclassical techniques based on ensembles of lattice simulations were applied to the problem of false vacuum decay. In this context, or any other lattice simulation, the effective potential experienced by long-wavelength modes is not the same as the bare potential. To make quantitative predictions using the real-time semiclassical techniques, it is therefore necessary to understand the redefinition of model parameters and the corresponding deformation of the vacuum state, as well as stochastic contributions that require modeling of unresolved subgrid modes. In this work, we focus on the former corrections and compute the expected modification of the true and false vacuum effective mass, which manifests as a modified dispersion relationship for linear fluctuations about the vacuum. We compare these theoretical predictions to numerical simulations and find excellent agreement. Motivated by this, we use the effective masses to fix the shape of a parametrized effective potential, and explore the modeling uncertainty associated with nonlinear corrections. We compute the decay rates in both the Euclidean and real-time formalisms, finding qualitative agreement in the dependence on the UV cutoff. These calculations further demonstrate that a quantitative understanding of the rates requires additional corrections.

Nav1.2 and BK channel interaction shapes the action potential in the axon initial segment.

In neocortical layer-5 pyramidal neurons, the action potential (AP) is generated in the axon initial segment (AIS) when the membrane potential (Vm ) reaches the threshold for activation of the voltage-gated Na+ channels (VGNCs) Nav 1.2 and Nav 1.6. Yet, whereas these VGNCs are known to differ in spatial distribution along the AIS and in biophysical properties, our understanding of the functional differences between the two channels remains elusive. Here, using ultrafast Na+ , Vm and Ca2+ imaging in combination with partial block of Nav 1.2 by the peptide G1 G4 -huwentoxin-IV, we demonstrate an exclusive role of Nav 1.2 in shaping the generating AP. Precisely, we show that selective block of ∼30% of Nav 1.2 widens the AP in the distal part of the AIS and we demonstrate that this effect is due to a loss of activation of BK Ca2+ -activated K+ channels (CAKCs). Indeed, Ca2+ influx via Nav 1.2 activates BK CAKCs, determining the amplitude and the early phase of repolarization of the AP in the AIS. By using control experiments using 4,9-anhydrotetrodotoxin, a moderately selective inhibitor of Nav 1.6, we concluded that the Ca2+ influx shaping the early phase of the AP is exclusive of Nav 1.2. Hence, we mimicked this result with a neuron model in which the role of the different ion channels tested reproduced the experimental evidence. The exclusive role of Nav 1.2 reported here is important for understanding the physiology and pathology of neuronal excitability. KEY POINTS: We optically analysed the action potential generated in the axon initial segment of mouse layer-5 neocortical pyramidal neurons and its associated Na+ and Ca2+ currents using ultrafast imaging techniques. We found that partial selective block of the voltage-gated Na+ channel Nav 1.2, produced by a recently developed peptide, widens the shape of the action potential in the distal part of the axon initial segment. We demonstrate that this effect is due to a reduction of the Ca2+ influx through Nav 1.2 that activates BK Ca2+ -activated K+ channels. To validate our conclusions, we generated a neuron model that reproduces the ensemble of our experimental results. The present results indicate a specific role of Nav 1.2 in the axon initial segment for shaping of the action potential during its generation.

Collision of two interacting electrons on a mesoscopic beam splitter: Exact solution in the classical limit

Experiments on collisions of isolated electrons guided along the edges in quantum Hall setups can mimic mixing of photons with the important distinction that electrons are charged fermions. In the so-called electronic Hong-Ou-Mandel (HOM) setup uncorrelated pairs of electrons are injected towards a beamsplitter. If the two electron wave packets were identical, Fermi statistics would force the electrons to scatter to different detectors, yet this quantum antibunching may be confounded by Coulomb repulsion. Here we model an electronic HOM experiment using a quadratic 2D saddle point potential for the beamsplitter and unscreened Coulomb interaction between the two injected electrons subjected to a strong out-of-plane magnetic field. We show that classical equations of motion for the drift dynamics of electrons' guiding centers take on the form of Hamilton equations for canonically conjugated variables subject to the saddle point potential and the Coulomb potential where the dynamics of the center-of-mass coordinate and the relative coordinate separate. We use these equations to determine collision outcomes in terms of a few experimentally tuneable parameters: the initial energies of the uncorrelated electrons, relative time delay of injection and the shape of the saddle point potential. A universal phase diagram of deterministic bunching and antibunching scattering outcomes is presented with a single energy scale characterizing the increase of the effective barrier height due to interaction of coincident electrons. We suggest clear-cut experimental strategies to detect the predicted effects and give analytical estimates of conditions when the classical dynamics is expected to dominate over quantum effects.

Bulk electronic structure of Mn2NiGa using hard x-ray photoelectron spectroscopy and density functional theory

Mn2NiGa is a potential magnetic shape memory alloy with austenite to the martensite phase transition. Here, we have investigated the bulk electronic structure of Mn2NiGa in the austenite and martensite phases studying its valence band using hard x-ray photoelectron spectroscopy (HAXPES). In the austenite phase, we observe a wide (≈10 eV) valence band (VB) spectrum with several prominent features. In order to explain the HAXPES VB spectra, we have compared our experimental VB spectra with the theoretical VB calculated using the partial density of states from our existing density functional theory (DFT) calculations. The shape of the experimental VB and energy positions of all features are in excellent agreement with the calculated VB and we find that the former is dominated by Ni 3d as well as 4s states of Mn, Ni, and Ga. An important observation is that experimental VB combined with the DFT-based VB calculation establishes the prevalence of the anti-site disorder in Mn2NiGa. Compared to the austenite phase, in the martensite phase, the VB shows a marginal decrease in the density of states around −0.5 eV below the Fermi level (E F ), and the main peak is slightly shifted towards E F . These experimental observations have been explained by considering the tetragonally distorted structure with the anti-site disorder in the martensite phase.

Adaptive basis sets for practical quantum computing

AbstractElectronic structure calculations on small systems such as H2, H2O, LiH, and BeH2 with chemical accuracy are still a challenge for the current generation of noisy intermediate‐scale quantum (NISQ) devices. One of the reasons is that due to the device limitations, only minimal basis sets are commonly applied in quantum chemical calculations, which allows one to keep the number of qubits employed in the calculations at a minimum. However, the use of minimal basis sets leads to very large errors in the computed molecular energies as well as potential energy surface shapes. One way to increase the accuracy of electronic structure calculations is through the development of small basis sets better suited for quantum computing. In this work, we show that the use of adaptive basis sets, in which exponents and contraction coefficients depend on molecular structure, provides an easy way to dramatically improve the accuracy of quantum chemical calculations without the need to increase the basis set size and thus the number of qubits utilized in quantum circuits. As a proof of principle, we optimize an adaptive minimal basis set for quantum computing calculations on an H2 molecule, in which exponents and contraction coefficients depend on the HH distance, and apply it to the generation of H2 potential energy surface on IBM‐Q quantum devices. The adaptive minimal basis set reaches the accuracy of the double‐zeta basis sets, thus allowing one to perform double‐zeta quality calculations on quantum devices without the need to utilize twice as many qubits in simulations. This approach can be extended to other molecular systems and larger basis sets in a straightforward manner.

Whole-cell patch-clamp recording and parameters.

The patch-clamp technique represents an electrophysiology type of method. This is one of several insightful approaches with five major configurations, namely a loose patch, cell-attached (also known as on-cell), whole-cell, inside-out, and outside-out modes. The patch-clamp method is more advanced compared to classical electrophysiology since it elucidates single-channel activation in a tiny portion of the membrane in addition to action potential (AP), junction potential (JP), endplate potential (EP), electrical coupling between two adjacent cells via Gap junction hemi-channels, excitatory/inhibitory postsynaptic potentials, and resting membrane potential (RMP). In fact, a malfunction of only one channel or even one component will alter AP amplitude or duration in vitro. If parameters are inferred appropriately and recordings are performed properly, the patch-clamp trace readouts and results are robust. The main hallmarks of currents via voltage-dependent calcium (Cav), hyperpolarization-activated cyclic nucleotide gated non-selective cation (HCN), inwardly rectifying potassium (Kir), voltage-dependent potassium (Kv), and voltage-dependent sodium (Nav) channels are similar and tractable among cells even when they are derived from evolutionary distinct organs and species. However, the size of the membrane area, where the functional subunits reside, and current magnitudes vary among cells of the same type. Therefore, dividing current magnitudes by cell capacitance- current density enables the estimate of functional and active channels relative to recorded cytoplasmic membrane area. Since the patch-clamp recordings can be performed in both current- and voltage-clamp modes, the action potential or spike durations can be adequately elucidated. Sometimes, optical methods are preferred to patch-clamp electrophysiology, but the obtained signals and traces are not robust. Finally, not only an alternans of AP durations, but also that of 'action potential shape' is observed with electrophysiology.

Ten questions concerning residential overheating in Central and Northern Europe

Rising global temperatures and more frequent heatwaves due to climate change have led to a growing body of research and increased policy focus on how to protect against the adverse effects of heat. In cold and temperate Europe, dwellings have traditionally been designed for cold protection rather than heat mitigation. There is, therefore, a need to understand the mechanisms through which indoor overheating can occur, its effects on occupants and energy consumption, and how we can design, adapt, and operate buildings during warm weather to improve thermal comfort and reduce cooling energy consumption. This paper brings together experts in overheating from across Europe to explore 10 key questions about the causes and risks from overheating in residential settings in Central and Northern Europe, including the way in which we define and measure overheating, its impacts, and its social and policy implications. The focus is not on summarising literature, but rather on identifying the evidence, key challenges and misconceptions, and limitations of current knowledge. Looking ahead, we outline actions needed to adapt, including the (re)design of dwellings, neighbourhoods, and population responses to indoor heat, and the potential shape of these actions. In doing so, we illustrate how heat adaptation is a multi-faceted challenge that requires urgent and coordinated action at multiple levels, but with feasible solutions and clear benefits for health and energy.

Effects of Schottky junction on surface waves in a piezoelectric semiconducting film over a metal substrate

Shear horizontal (SH) waves propagating in a metal substrate covered with a transversely isotropic piezoelectric semiconductor thin film is analyzed in the present paper. The Schottky junction, which is created by the metal and the n-type piezoelectric semiconductor with a higher Fermi level, can be seen as an electrically gradient layer between the substrate and the thin film. The transfer matrix of the Schottky junction is derived by using Magnus series expansion and approximate laminated medium methods, respectively. The influences of the Schottky junction, semiconductor coupling, doping density, and electric boundary conditions on the dispersion and attenuation and the first three wave modes are discussed via numerical example. It reveals that numerical results obtained by these two methods are well matched and the existence of Schottky junction has less influence on the dispersion of SH surface wave although, but evidently influences on the attenuation. In particular, the mode shapes of electric potential, electric displacement, carrier perturbation density, and the electric current density are affected evidently by the existence of Schottky junction.

Resonance Structure of 8Be within the Two-Cluster Resonating Group Method

A microscopic two-cluster model is applied to study the elastic alpha-alpha scattering and the resonance structure of 8Be. The model is an algebraic version of the Resonating Group Method (RGM), which involves the complete set of oscillator functions to expand the wave function of a two-cluster system. The interaction of nucleons inside each cluster and the interaction between clusters are determined by the well-known semirealistic nucleon-nucleon potentials which are employed in calculations. They differ by a size of the core at small distances between nucleons and realize the strong, moderate, and weak cores. They allow us to study dependence of calculated quantities on the shape of a nucleon-nucleon potential. The detailed analysis of resonance wave functions is carried out in the oscillator, coordinate, and momentum spaces. Effects of the Pauli principle on the wave functions of the 8Be continuous spectrum states are thoroughly studied.

Spatial assembly of grassland communities and interrelationships with productivity

AbstractKnowledge on the fine‐scale spatial aggregation is pertinent for deciphering plant community dynamics, as interactions among sessile plants mainly occur in the neighbourhood. However, the spatial assemblage mechanism and interrelationships with productivity remain poorly understood.Here, species segregation index (Mscom) was used to quantify the interspecific segregation (or intraspecific aggregation) of the neighbourhood in plant communities from three contrasting plateaus. We employed the coordinates for 125,726 individual plants (within 1 m2plots) sampled in natural grassland communities across two temperate grasslands (Loess Plateau and Mongolian Plateau) and one alpine grassland (Tibetan Plateau) to elucidate the assembly mechanisms of Mscomand interrelationships with above‐ground net primary productivity (ANPP).We found that these grassland communities tended to assemble into intraspecific aggregations; the phenomenon was more apparent in regions with low annual precipitation. In grassland communities on Loess Plateau, the strong intraspecific aggregation was mainly due to low sexual reproduction allocation; on Mongolian Plateau, reproductive allocation was also the dominant factor for Mscomvariation, followed by the interactive effect of annual precipitation and species richness, whereas on Tibetan Plateau, low species richness was the main reason for increased intraspecific aggregation, followed by the interactive effect of annual precipitation and species richness, and reproductive allocation. More importantly, on all three plateaus, the independent influence of Mscomon ANPP is stronger than that of species and phylogenetic diversity.We elucidated the potential mechanisms shaping spatial aggregation in grassland communities at large scale, and emphasize the critical role of spatial aggregation in predicting the variation of ANPP.Read the freePlain Language Summaryfor this article on the Journal blog.