energy gradient
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Irriga ◽  
2022 ◽  
Vol 1 (4) ◽  
pp. 739-747
Author(s):  
Madson Rafael Barbalho da Silva ◽  
Lívia Maria Cavalcante Silva ◽  
Ana Cláudia Davino dos Santos ◽  
Fabiano Simplicio Bezerra ◽  
Caio Sérgio Pereira de Araújo ◽  
...  

AVALIAÇÃO DE DESEMPENHO DO MICROASPERSOR EM LINHA LATERAL E SIMULAÇÃO MATEMÁTICA DE SEU GRADIENTE DE ENERGIA     MADSON RAFAEL BARBALHO DA SILVA1; LÍVIA MARIA CAVALCANTE SILVA1; ANA CLÁUDIA DAVINO DOS SANTOS1; FABIANO SIMPLICIO BEZERRA1; CAIO SÉRGIO PEREIRA DE ARAÚJO1 E MANASSÉS MESQUITA DA SILVA1   1 Departamento de Engenharia Agrícola, Universidade Federal Rural de Pernambuco, Dom Manuel de Medeiros, s/n, Dois Irmãos, 52171-900, Recife, Pernambuco, Brasil. E-mail:[email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected].     1 RESUMO   Objetivou-se avaliar o desempenho do microaspersor Agropolo modelo MC20 em diferentes condições hidráulicas, gerando informações para um melhor dimensionamento de sistemas de microirrigação e manejo da água em áreas irrigadas. A condução do projeto hidráulico para simulação do gradiente de energia em linhas laterais, considerou-se informações determinadas através da escolha de componentes do projeto. Foram extraídos do catálogo comercial do fabricante os pares de valores referentes a vazão e a pressão e, a partir destes, gerou-se a curva vazão-pressão, onde a simulação foi feita pelo Método Algébrico - Christiansen (MA) e Método Iterativo (SBS) – Back-Step. Para ambos métodos o microaspersor se comportou de maneira semelhante, quando submetido a condições sugeridas pelo fabricante, num espaçamento entre emissores de 5,2 m, usando tubos de polietilenos de diâmetro interno de 13 mm e uma pressão de serviço de 20 mca, admitindo uma variação de 10% da pressão. Foram calculados os coeficientes de uniformidade de pressão (CUp) e de vazão (CUq), ambos com valores superiores à 95%, demonstrando a excelência no desempenho do emissor.   Palavras-chave: hidráulica, modelagem matemática, coeficiente de descarga.     SILVA, M. R. B.; SILVA, L. M. C.; SANTOS, A. C. D.; BEZERRA, F. S.; ARAUJO, C. S. P.; SILVA, M. M. PERFORMANCE EVALUATION OF THE SIDE LINE MICROSPARENT AND MATHEMATICAL SIMULATION OF ITS ENERGY GRADIENT     2 ABSTRACT   The objective was to evaluate the performance of the Agropolo model MC20 microsprinkler under different hydraulic conditions, generating information for a better design of micro-irrigation systems and water management in irrigated areas. The conduction of the hydraulic project to simulate the energy gradient in lateral lines, considered information determined through the choice of project components. The pairs of values ​​referring to flow and pressure were extracted from the manufacturer's commercial catalog and, from these, the flow-pressure curve was generated, where the simulation was performed using the Algebraic Method - Christiansen (MA) and Iterative Method (SBS) – Back-Step. For both methods, the microsprinkler behaved similarly, when subjected to conditions suggested by the manufacturer, in a spacing between emitters of 5.2 m, using polyethylene tubes with an internal diameter of 13 mm and a working pressure of 20 mca, admitting a 10% pressure variation. The uniformity of pressure (CUp) and flow (CUq) coefficients were calculated, both with values ​​above 95%, demonstrating the excellence in the performance of the emitter.   Keywords: hydraulic, mathematical modeling, discharge coefficient.


Author(s):  
Suresh K

We are on a planet that orbits the Sun which emits a huge amount of energy. The climate we experience is a result of an energy gradient across Earth and an imbalance in energy across the world due to axial tilt of Earth rotation.


2021 ◽  
Author(s):  
Juejie Yang ◽  
Zheng Pei ◽  
Erick Calderon Leon ◽  
Carly Wickizer ◽  
Binbin Weng ◽  
...  

Following the formulation of cavity quantum electrodynamical time-dependent density functional theory (cQED-TDDFT) models [Flick et al., ACS Photonics 6, 2757-2778 (2019); Yang et al., J. Chem. Phys. 155, 064107 (2021)], here we report the derivation and implementation of the analytic energy gradient for the polaritonic states of a single photochrome within the cQED-TDDFT models. Such gradient evaluation is also applicable to a complex of explicitly-specified photochromes, or, with proper scaling, a set of parallel-oriented, identical-geometry, non-interacting molecules in the microcavity.


Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8338
Author(s):  
Kunhang Li ◽  
Wenqian Xu ◽  
Hua-Shu Dou

The flow behavior inside a miniature centrifugal pump, under a periodic pulse flow rate, was studied by means of numerical simulation. For a given incoming periodic pulse flow with a sine wave, the performance of the centrifugal pump was investigated in the section with increasing flow and the section with decreasing flow, and the special points of the flow rate and the periodic flow were identified. Further, the energy gradient method and the Q-criterion were adopted to analyze the internal vertical structure and flow stability. It was found that the regions with large variations in velocity and total pressure were mainly located at the leading edge of the suction surface and the middle area of the pressure surface of the blades. Irregular pressure fluctuation frequency under the periodic pulse flow was shown; this was mainly concentrated in the low-frequency zones close to the impeller’s rotational frequency. In addition, for the same flow rate in the periodic pulse flow, the pressure frequency fluctuation for the increasing flow rate section was higher than that observed for the decreasing flow rate section. It was found that the most unstable sections appeared in the first half-period of the flow rate variation (large flow rate), according to the distributions of the Q criteria of the vortex and the energy gradient function K. In this section, motions of strong vortices led to large gradients of the mechanical energy.


2021 ◽  
Vol 16 (9) ◽  
pp. 29
Author(s):  
David Leong

Entrepreneurship researches started to have traction at the start of 1980 and underwent paradigmatic shift. However despite the varied veins of exploration from opportunities to innate traits, entrepreneurship literatures have yet developed a unifying conceptualization and theory with key concepts that can clearly explain why entrepreneurs act the way they do? What inspires them to action? What seduce them to move at all? This paper intends to relate the study of entrepreneurship, entrepreneurial actions and activities with references to thermodynamic and energy gradient manipulation mechanism. Studying business ventures from a process view in an attempt to reconstruct the entrepreneurial process by illustrating a range of relevant perspectives from energy gradients in naturally occurring chemicals and suspension coils, this paper hopes to pull together a unifying theory on entrepreneurship basing on the forces at work with thermodynamic concepts and expressions with gradient-manipulation mechanism to explain the entrepreneurial action-motion phenomena. The gradient-manipulating mechanism and thermodynamic expressions thus become the “nature” invisible hand that operates the motion of actions. Kirzner’s theory of entrepreneurship explains the coordination of markets and of knowledge. It is that knowledge, the recognition of the opportunities in the actual imperfect markets that triggers the gradient-manipulation mechanism. The findings of this paper suggest that entrepreneurial actions are force-driven by the lure of profits to select of best pathways and means to achieve the ends. The idea that entrepreneurial actions are the results of the play of forces with thermodynamic forces at work is a powerful suggestion in the finding of this paper.


Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 473
Author(s):  
Bo Peng ◽  
Karol Kowalski

Recently a new class of quantum algorithms that are based on the quantum computation of the connected moment expansion has been reported to find the ground and excited state energies. In particular, the Peeters-Devreese-Soldatov (PDS) formulation is found variational and bearing the potential for further combining with the existing variational quantum infrastructure. Here we find that the PDS formulation can be considered as a new energy functional of which the PDS energy gradient can be employed in a conventional variational quantum solver. In comparison with the usual variational quantum eigensolver (VQE) and the original static PDS approach, this new variational quantum solver offers an effective approach to navigate the dynamics to be free from getting trapped in the local minima that refer to different states, and achieve high accuracy at finding the ground state and its energy through the rotation of the trial wave function of modest quality, thus improves the accuracy and efficiency of the quantum simulation. We demonstrate the performance of the proposed variational quantum solver for toy models, H2 molecule, and strongly correlated planar H4 system in some challenging situations. In all the case studies, the proposed variational quantum approach outperforms the usual VQE and static PDS calculations even at the lowest order. We also discuss the limitations of the proposed approach and its preliminary execution for model Hamiltonian on the NISQ device.


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 988
Author(s):  
Zhongqian Jiang ◽  
Xiaodong Zeng ◽  
Yi Li

In order to study the wear characteristic of a centrifugal pump at different mass concentrations, simulation and experimental research were carried out. The simulation was based on the DPM (discrete phase model) to complete the coupling of particles and the flow field. The experimental research included a performance test and a wear test. Through the comparison of the simulation and experimental research results, the relationship between the particle movement and the wear was analyzed, and the flow field was analyzed through the energy gradient theory. The energy gradient and the particle movement were combined to explain the wear characteristics. When the particles entered the impeller flow area, they directly hit the leading edge of the blade and the hub wall. The particles were sinking due to the flow field, which caused the particles to accumulate near the hub and the pressure surface. These places were at the most severely worn wall. The farther away from the axis the position was, the greater the relative velocity difference between the particles and the wall was, so that wear occurred first in these places. The low-energy properties near the hub made particles gather there, which was also the most serious cause of hub wear.


2021 ◽  
Author(s):  
David Leong

<div> <div> <div> <p>Up until now, entrepreneurship study has not developed a unified theory with key concepts that can elucidate the holistically process-driven characteristics of entrepreneurial venturing. What spur entrepreneurs to action along the process-driven pathway? This paper intends to relate the business of entrepreneurship and entrepreneurial actions and activities to thermodynamic and energy gradient-manipulation mechanism. Taking entrepreneurial venturing from a process view and in an attempt to reconstruct the entrepreneurial process by illustrating a range of relevant perspectives from energy gradients in naturally occurring chemical , biological and physical systems basing on interpretive and phenomenological, social constructionist angle; this paper hopes to pull together a unifying theory on action-based activities in entrepreneurial venturing with thermodynamic concepts and expressions with gradient-manipulation mechanism to explain the entrepreneurial action-motion phenomena. The gradient-manipulating mechanism and thermodynamic expressions thus become the “nature” invisible hand that operates the motion of actions. Kirzner’s theory of entrepreneurship explains the coordination of markets and of knowledge. It is that knowledge, the recognition of the opportunities in the actual imperfect markets that triggers the gradient-manipulation mechanism. </p> </div> </div> </div>


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