Coherent Path Research Articles

Pāṇinian Grammar: An Effective Approach to Samāsa (Compounds) Study with reference to Dharmakīrti’s Rūpāvatāra

Pāṇinian grammar is a prescriptive and generative grammar that governs every aspect of Sanskrit language. Pāṇini composed the Aṣṭādhyāyī in sūtra-style with eight chapters that are considered the cornerstone of Sanskrit grammar. It is accompanied by excellent commentaries of Patanjali’s Mahābhāṣya and Kātyāyana’s Vārtikā, which were crucial in transforming the Pāṇinian grammar into a coherent structural path. The composition of the Kāśikāvṛtti of Jayāditya and Vāmana, together with the Nyāsa by Jinendrabuddhi and the Padamañjari by Haradatta broadened the second stage of Pāṇinian grammar by incorporating definitions and commentaries thereon. The Rūpāvatāra of Dharmakīrti is the initiative work of the prakriyā-style of Pāṇinian grammar that formulated grammatical aspects into a subject-wise methodology and is also considered the beginning of the third stage of Pāṇinian grammar. However, the Rūpāvatāra garnered limited attention from the researchers. The Samāsāvatāra of the Rūpāvatāra, which provides the complete forms of compounds, serves as the basis of this research. Regarding the outcomes, Dharmakīrti has employed a pragmatic approach to teach the compound forms in a way that is compatible with beginners of the subject. The research findings will be carried out by paying close attention to explanation techniques, contents, and other peculiarities of each sub-section in samāsāvatāra.

Acqua da coltivare. Risorsa, strumento e rito dell’abitare il paesaggio mediterraneo

Walafrid Strabo's Hortulus, a treaty on agriculture written in the 6th century AD, refers techniques and practices for drainage and irrigation of fields nowadays at the centre of discussion (Zoppi, 1995). The theme is particularly critical when compared with the invasiveness of many contemporary systems. The topic of water management represents a feature of human experience on earth since its appearance. It is also one of the most continuous – perhaps the most necessary – tools in landscape construction. While innovating over time, water techniques maintain codes, customs, even rituals, according to constant and apparently opposite principles of rationality and imageability. Reason and figure, utility and symbol, survival and myth lead the construction of the human settlement around water and this contribution tries to outline some of its features especially as regards the "immenso deposito di fatiche" (Cattaneo, 1868) constituted by Mediterranean agricultural landscape and its inhabiting forms. If, on the one hand, a complex and heterogeneous picture can emerge in the experiences described, on the other the essay tries to retrace a coherent path. Finally, this tries to provide a perspective that is still possible for a landscape society, the Mediterranean one, in which living and cultivating water do not belong only to a necessity but to a real and inescapable identity.

Anisotropic and Coherent Control of Radical Pairs by Optimized RF Fields.

Radical pair kinetics is determined by the coherent and incoherent spin dynamics of spin pair and spin-selective chemical reactions. In a previous paper, reaction control and nuclear spin state selection by designed radiofrequency (RF) magnetic resonance was proposed. Here, we present two novel types of reaction control calculated by the local optimization method. One is anisotropic reaction control and the other is coherent path control. In both cases, the weighting parameters for the target states play an important role in the optimizing of the RF field. In the anisotropic control of radical pairs, the weighting parameters play an important role in the selection of the sub-ensemble. In coherent control, one can set the parameters for the intermediate states, and it is possible to specify the path to reach a final state by adjusting the weighting parameters. The global optimization of the weighting parameters for coherent control has been studied. These manifest calculations show the possibility of controlling the chemical reactions of radical pair intermediates in different ways.

Современные принципы организации университетских музеев и выставочных пространств

Introduction. Today, many university museums around the world are facing the need to revise the principles of their activities in order to fully integrate into the daily life of their educational institutions. The main functions for such museums are patriotic, image-building, educational, educational and career guidance. Modern challenges include attracting not only students and applicants, but also a wider audience. Challenges of introducing new technologies will make them more relevant to younger generation. However, without defining the main purpose of the museum’s existence, it is impossible to build a coherent path for its development. Purpose. To determine the basic principles of exhibition organisation and its placement in the structure of a university campus, depending on the nature of the museum and the image of the educational institution. Results. Using the example of museums of the world’s largest universities, the specifics of their location depending on specialisation, the correlation between the organization of space and the theme of the exhibition, the characteristics of exhibition equipment, the principles of placement of different types of expositions in the structure of campuses are determined. Conclusions. It has been found that when the university is image oriented towards history and traditions, the museums are located in historical buildings and have a more familiar spatial structure and principles exhibition organization. In the case of striving to demonstrate the innovative nature of the university, the priority is given to the placement in the most accessible and technologically advanced modern buildings. Exhibitions related to the current life of the university are housed in more light, versatile and democratic spaces. The latest trend is the active use of multimedia and interactivity.

Da Preparação do Texto à Delineação de Estratégias Pedagógicas um Possível Percurso de Compreensão da Leitura da Obra O Dragão, de Luísa Ducla Soares

The present article intends to reflect on the work of preparing the text before delineating pedagogical strategies, valuing the linguistic knowledge of the Portuguese L1 teacher for the delineation of a sustained and coherent didactic path. The text assumes the central role of the class countless times, trying to make the student reflect on their linguistic structures. In this context, the book O Dragão, by Luísa Ducla Soares, constitutes the starting point for exemplifying a possible text preparation work. It is intended to emphasize that this previous moment of textual analysis allows highlighting the pedagogical potential of the text, so that, in a second moment, depending on the objectives and the class, a didactic route can be defined. Finally, it is in this line, in which text and reading are assumed as fundamental aspects in Portuguese classes, that a possible reading route is presented, taking into account the specific methodology of this domain.

Lefschetz thimble quantum Monte Carlo for spin systems

Monte Carlo simulations are useful tools for modeling quantum systems, but in some cases they suffer from a sign problem, leading to an exponential slow down in their convergence to a value. While solving the sign problem is generically NP hard, many techniques exist for mitigating the sign problem in specific cases; in particular, the technique of deforming the Monte Carlo simulation's plane of integration onto Lefschetz thimbles (complex hypersurfaces of stationary phase) has seen significant success in the context of quantum field theories. We extend this methodology to spin systems by utilizing spin coherent state path integrals to reexpress the spin system's partition function in terms of continuous variables. Using some toy systems, we demonstrate its effectiveness at lessening the sign problem in this setting, despite the fact that the initial mapping to spin coherent states introduces its own sign problem. The standard formulation of the spin coherent path integral is known to make use of uncontrolled approximations; despite this, for large spins they are typically considered to yield accurate results, so it is somewhat surprising that our results show significant systematic errors. Therefore, possibly of independent interest, our use of Lefschetz thimbles to overcome the intrinsic sign problem in spin coherent state path integral Monte Carlo enables a novel numerical demonstration of a breakdown in the spin coherent path integral.

Collapse-revival of entanglement in a non-commutative harmonic oscillator revealed via coherent states and path integral

Abstract We develop an approach using coherent states and path integral to investigate the dynamics of entanglement in a simple two-dimensional non-commutative harmonic oscillator. We start by employing a Bopp shift to convert the Hamiltonian describing the system into a commutative equivalent one. This allows us to construct coherent states and calculate the propagator in standard way. By deriving the explicit expression of the time-dependent coherent states and considering its connection with the number states, we provide exact results for evaluating the degree of entanglement between the ground state and any excited state through the purity function. The interesting emerging result is that, as long as the non-commutativity parameter is non-zero, our system exhibits the phenomenon of collapse and revival of entanglement.

Career Path Decisions and Sustainable Options

Career planning has become more important than standalone job decisions in the current environment, where individuals have a wider range of choices of occupations and jobs than ever before. This paper reviews the theoretical developments in career guidance theory and recommends a holistic approach towards ‘Career Path Guidance’, incorporating psychological, sociological and developmental perspectives. An approach that considers several future steps in a career cannot be without challenges. The contextual and environmental situations along with individual characteristics are subject to change along a career path. Additionally, different stages in a career path are another variable that needs consideration to achieve a sustainable future. It has, therefore, been proposed that the career course be mapped by considering external factors, internal improvements and path-related dynamism. A multidimensional understanding of career guidance and the amount, complexity and sensitivity of the data involved mean that this approach may be better executed using computer-assisted systems that can source and logically analyze a large amount of information from several sources to produce coherent, sustainable and practical career path decisions.

Sigma-model analysis of SU(3) antiferromagnetic spins on the triangular lattice

Using field-theoretic techniques, we study the $\mathrm{SU}(3)$ analog of antiferromagnetic Heisenberg spin model on the triangular lattice putting the $p$-box symmetric representation on each site. Taking the large-$p$ limit, we show that the low-energy effective theory is described by a $(2+1)$-dimensional relativistic $\mathrm{SU}(3)/\mathrm{U}{(1)}^{2}$ nonlinear sigma model. Since the target space has a nontrivial homotopy ${\ensuremath{\pi}}_{2}(\mathrm{SU}(3)/\mathrm{U}{(1)}^{2})\ensuremath{\simeq}{\mathbb{Z}}^{2}$, this model has two kinds of magnetic skyrmions, which can be created and annihilated by monopole instantons. By careful analysis of the Wess-Zumino term in the spin coherent path integral, we compute the Berry phase for these monopoles and it produces the destructive interference. This restricts possible perturbations of the effective Lagrangian by monopole operators, and we see that the valence-bond-solid (VBS) phase should have degenerate ground states when $p\ensuremath{\notin}3\mathbb{Z}$. We also compute 't Hooft anomalies to constrain possible phases of this system, and a direct phase transition between N\'eel and VBS phases is supported from the anomaly matching.

Automation technology as a key component of the Industry 4.0 production development path

Since 2011, the Industry 4.0 initiative is a key research and development direction towards flexible production systems in Germany. The objective of the initiative is to deal with the challenge of an increased production complexity caused by various factors such as increasing global competition between companies, product variety, and individualization to meet customer needs. For this, Industry 4.0 envisions an overarching connection of information technologies with the production process, enabling smart manufacturing. Bringing current production systems to this objective will be a long transformation process, which requires a coherent migration path. The aim of this paper is to represent an exemplary production development way towards Industry 4.0 using eminent formalization approaches and standardized automation technologies.

Self-adjointness in quantum mechanics: a pedagogical path

Observables in quantum mechanics are represented by self-adjoint operators on Hilbert space. Such ubiquitous, well-known, and very foundational fact, however, is traditionally subtle to be explained in typical first classes in quantum mechanics, as well as to senior physicists who have grown up with the lesson that self-adjointness is "just technical". The usual difficulties are to clarify the connection between the demand for certain physical features in the theory and the corresponding mathematical requirement of self-adjointness, and to distinguish between self-adjoint and hermitian operator not just at the level of the mathematical definition but most importantly from the perspective that mere hermiticity, without self-adjointness, does not ensure the desired physical requirements and leaves the theory inconsistent. In this work we organise an amount of standard facts on the physical role of self-adjointness into a coherent pedagogical path aimed at making quantum observables emerge as necessarily self-adjoint, and not merely hermitian operators. Next to the central core of our line of reasoning -- the necessity of a non-trivial declaration of a domain to associate with the formal action of an observable, and the emergence of self-adjointness as a consequence of fundamental physical requirements -- we include some complementary materials consisting of a few instructive mathematical proofs and a short retrospective, ranging from the past decades to the current research agenda, on the self-adjointness problem for quantum Hamiltonians of relevance in applications.

Exploration of the relationship among roadway characteristics, operating speed, and crashes for city streets using path analysis

Estimating the speed-crash relationship has long been a focus area of interest in roadway safety analysis. Because of many confounding factors that may influence both speeds and crashes, the relationship cannot be appropriately established without considering the corresponding roadway contexts and accounting for their effects on speeds and crashes. This paper investigates the speed-crash relationship for city streets by jointly modeling speed, roadway characteristics, and crashes using a path analysis approach that has been recently introduced into safety analysis while incorporating a wide range of roadway and traffic related variables and additional speed measures. The results from the coherent path analysis identified multiple speed measures of interest that have a statistically significant association with crashes as well as having intuitive and useful interpretation. The results also supported a positive relationship between speed variability and crash occurrence (i.e., larger spread/variability in operational speed is associated with more crashes).

Accuracy of the Cell-Set Model on a Single Vane-Type Vortex Generator in Negligible Streamwise Pressure Gradient Flow with RANS and LES

Passive flow control devices are included in the design of wind turbine blades in order to obtain better performance and reduce loads without consuming any external energy. Vortex Generators are one of the most popular flow control devices, whose main objective is to delay the flow separation and increase the maximum lift coefficient. Computational Fluid Dynamics (CFD) simulations of a Vortex Generator (VG) on a flat plate in negligible streamwise pressure gradient conditions with the fully-resolved mesh model and the cell-set model using Large Eddy Simulation (LES) and Reynolds-Averaged Navier-Stokes (RANS) were carried out, with the objective of evaluating the accuracy of the cell-set model taking the fully-resolved mesh model as benchmark. The implementation of the cell-set model entailed a considerable reduction of the number of cells, which entailed saving simulation time and resources. The coherent structures, vortex path, wall shear stress and size, strength and velocity profiles of the primary vortex have been analyzed. The results show good agreements between the fully-resolved mesh model and the cell-set mode with RANS in all the analyzed parameters. With LES, acceptable results were obtained in terms of coherent structures, vortex path and wall shear stress, but slight differences between models are visible in the size, strength and velocity profiles of the primary vortex. As this is considered the first application of the cell-set model on VGs, further research is proposed, since the implementation of the cell-set model can represent an advantage over the fully-resolved mesh model.

Star product representation of coherent state path integrals

In this paper, we determine the star product representation of coherent path integrals. By employing the properties of generalized delta functions with complex arguments, the Glauber–Sudarshan P-function corresponding to a non-diagonal density operator is obtained. Then, we compute the Husimi–Kano Q-representation of the time evolution operator in terms of the normal star product. Finally, the optical equivalence theorem allows us to express the coherent state path integral as a star exponential of the Hamiltonian function for the normal product.

Measurements of spin–orbit interaction in epitaxially grown InAs nanosheets

We report a low-temperature transport study of a single-gate, planar field-effect device made from a free-standing, wurtzite-crystalline InAs nanosheet. The nanosheet is grown via molecular beam epitaxy and the field-effect device is characterized by gate transfer characteristic measurements and by magnetic field orientation dependent transport measurements. The measurements show that the device exhibits excellent electrical properties and the electron transport in the nanosheet is of a two-dimensional nature. Low-field magnetoconductance measurements are performed for the device at different gate voltages and temperatures, and the characteristic transport lengths, such as phase coherent length, spin–orbit length, and mean free path, in the nanosheet are extracted. It is found that the spin–orbit length in the nanosheet is short, on the order of 150 nm, demonstrating the presence of strong spin–orbit interaction in the InAs nanosheet. Our results show that epitaxially grown, free-standing, InAs nanosheets can serve as an emerging semiconductor nanostructure platform for applications in spintronics, spin qubits, and planar topological quantum devices.

The (changing) consideration of social investment in the design of welfare benefits: The case of poverty relief in Austria

AbstractThe social investment perspective has become a prominent topic in both social policy discussions and theoretical considerations regarding welfare state change. Empirical evidence on how this perspective has affected welfare state provision is much scarcer—and sometimes contradictory. This article aims to assess whether welfare state benefits increasingly have incorporated elements of social investment, and what has triggered the reforms made to the benefits. To achieve these aims, we examined two poverty relief benefits in Austria, namely, unemployment assistance and social assistance. We scrutinized changes made to these benefits from 2000 onwards. To identify their (potentially changing) contributions towards social investment, we applied a framework that considers the economic aims of the paradigm (while neglecting other aims). According to this framework, a social investment benefit intends to improve the human capital of its recipients, enhance their employability, and/or enhance their employment integration. The findings suggest that the three elements of social investment were particularly relevant in reforming social assistance. However, the changes implemented were incoherent and do not support the hypothesis of an ever‐increasing significance of social investment. The main triggers for reform were the political ideologies of (changing) governments. These ideologies determined the direction of changes made to both social assistance and unemployment assistance. If social investment thus ought to be more than just a theoretical concept or a nonbinding policy recommendation, modifications made to welfare state benefits would need to follow a more coherent path. Regarding poor relief benefits, Austria has not pursued such a track (yet).

Time-varying optical vortices enabled by time-modulated metasurfaces

Abstract In this paper, generation of optical vortices with time-varying orbital angular momentum (OAM) and topological charge is theoretically demonstrated based on time-modulated metasurfaces with a linearly azimuthal frequency gradient. The topological charge of such dynamic structured light beams is shown to continuously and periodically change with time evolution while possessing a linear dependence on time and azimuthal frequency offset. The temporal variation of OAM yields a self-torqued beam exhibiting a continuous angular acceleration of light. The phenomenon is attributed to the azimuthal phase gradient in space-time generated by virtue of the spatiotemporal coherent path in the interference between different frequencies. In order to numerically authenticate this newly introduced concept, a reflective dielectric metasurface is modelled consisting of silicon nanodisk heterostructures integrated with indium-tin-oxide and gate dielectric layers on top of a mirror-backed silicon slab which renders an electrically tunable guided mode resonance mirror in near-infrared regime. The metasurface is divided into several azimuthal sections wherein nanodisk heterostructures are interconnected via nanobars serving as biasing lines. Addressing azimuthal sections with radio-frequency biasing signals of different frequencies, the direct dynamic photonic transitions of leaky-guided modes are leveraged for realization of an azimuthal frequency gradient in the optical field. Generation of dynamic twisted light beams with time-varying OAM by the metasurface is verified via performing several numerical simulations. Moreover, the role of modulation waveform and frequency gradient on the temporal evolution and diversity of generated optical vortices is investigated which offer a robust electrical control over the number of dynamic beams and their degree of self-torque. Our results point toward a new class of structured light for time-division multiple access in optical and quantum communication systems as well as unprecedented optomechanical manipulation of objects.

Coherent State-Based Path Integral Methodology for Computing the Wigner Phase Space Distribution.

The accurate evaluation of the Wigner phase space density for multidimensional system remains a challenging task. Path integral Monte Carlo methods offer a numerically exact approach for obtaining the Boltzmann density in coordinate space, but the Fourier-type integral required to construct the Wigner distribution generally leads to poor convergence. This paper describes a path integral method for constructing the Wigner density which substantially mitigates the Monte Carlo sign problem and thus is applicable to systems with many degrees of freedom. The starting point is the path integral representation of the coherent state density, which does not involve a Fourier integral and thus converges rapidly. We then use the relation between the coherent state and Wigner densities to construct the Wigner function, taking advantage of destructive phase cancellation to truncate the infinite series and thus confine the integrand, avoiding highly oscillatory regions. We also describe the use of information-guided noise reduction (IGNoR) to improve the Monte Carlo statistics in the most challenging regimes. The method is applied to strongly anharmonic one-dimensional models, a system-bath Hamiltonian, as well as the formamide molecule within an ab initio quartic potential, and the results are compared to those obtained by various approximate methods. These calculations suggest that the coherent state-based path integral method described in this paper offers an efficient, numerically exact approach for constructing the Wigner phase space density in systems of many degrees of freedom, and thus will be useful for quantizing the initial condition in classical trajectory-based simulations of dynamical properties.

The European roadmap towards fusion electricity.

The European roadmap to the realization of fusion electricity breaks the quest into eight missions. For each mission, it reviews the current status of research, identifies open issues, and proposes a research and development programme. ITER is the key facility on the roadmap as it is expected to achieve most of the important milestones on the path to fusion power. The Fusion Roadmap is tightly connected to the ITER schedule and the vast majority of resources in fusion research are presently dedicated to ITER and its accompanying experiments. Parallel to the ITER exploitation in the 2030s, the construction of the demonstration power plant DEMO needs to be prepared. DEMO will for the first time supply fusion electricity to the grid and it will have a self-sufficient fuel cycle. The design, construction and operation of DEMO require full involvement of industry to ensure that, after a successful DEMO operation, industry can take responsibility for commercial fusion power. The European fusion roadmap provides a coherent path towards the fusion power plant, and it proposes in an integrated way to find solutions for all challenges that still need to be addressed.This article is part of a discussion meeting issue ‘Fusion energy using tokamaks: can development be accelerated?’

Alcoholic extracts from Paulownia tomentosa leaves for silver nanoparticles synthesis

Abstract Paulownia tomentosa (P. tomentosa) is a hardwood tree that has economic and scientific relevance but has no use as food. For that reason, we selected it to conduct a study on the synthesis of silver nanoparticles (AgNPs) using hydroalcoholic extracts from its leaves. Phytochemical sources had been widely used as reducing agents for synthesis of nanoparticles. Our work is the first approach for studying the correlation between the composition of the extracts and the AgNPs synthesis features. Isopropyl alcohol, ethanol, and water were proposed as extraction solvents. Nanoparticles were characterized by UV–vis, FTIR, and Scanning Electron Microscopy/Energy Dispersive X-ray spectroscopy (SEM/EDX) and the Antimicrobial activity was evaluated. Our findings suggest that the composition of the extracts varies with the selection of the extraction solvent. This is relevant because solvents with similar characteristics and polarity (isopropyl alcohol and ethanol) produced different AgNPs features such as ζ potential that was −20.5 ± 0.41, −25 ± 0.12 and 31 ± 0.79 mV for samples extracted with isopropyl alcohol, ethanol, and water, respectively. Samples obtained with isopropyl alcohol produced nanoparticles with the highest antioxidant activity and stability. Also, we found that size, shape, reaction kinetics, and bactericidal properties have a strong correlation with the composition of the plant extract. Our results justify the use of a wide range of extraction solvents to obtain detail implications on size and shape of nanoparticles, and the use of chromatographic techniques to determine each fraction composition. Our investigation is the first step in a coherent path to propose reaction mechanisms on nanoparticles synthesis using complex mixtures from Paulownia tomentosa extracts.