scholarly journals THM analysis of a soil drying test in an environmental chamber: The role of boundary conditions

2022 ◽  
Vol 141 ◽  
pp. 104495
Author(s):  
Agustín Cuadrado ◽  
Abdallah Najdi ◽  
Alberto Ledesma ◽  
Sebastià Olivella ◽  
Pere C. Prat
Keyword(s):  
Boundary Conditions ◽  
Soil Drying ◽  
Environmental Chamber ◽  
Drying Test

Determining preference for potential: The role of perceived economic mobility

2019 ◽  
Vol 47 (6) ◽  
pp. 1-8 ◽  
Author(s):  
Chen Yang ◽  
Shaochen Zhao
Keyword(s):  
Boundary Conditions ◽  
Economic Mobility ◽  
Individual Perceptions ◽  
Future Success ◽  
The Future

Although previous researchers have demonstrated that people often prefer potential rather than achievement when evaluating other people or products, few have focused on the boundary conditions on this effect. We proposed that the preference for potential would emerge when individuals’ perception of economic mobility was high, but the preference for achievement would emerge among individuals with low perceptions of economic mobility. Our results showed that people paid more attention to the future (vs. the present) when their perception of economic mobility was high; this, in turn, promoted more favorable reactions toward potential (vs. achievement). Thus, we suggested circumstances under which highlighting a person’s potential for future success is effective and those when it is not effective. Moreover, we revealed the important role of individual perceptions regarding economic mobility in driving this effect.

scholarly journals Charge algebra in Al(A)dSn spacetimes

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Adrien Fiorucci ◽  
Romain Ruzziconi
Keyword(s):  
Boundary Conditions ◽  
Dirichlet Boundary ◽  
Three Dimensional ◽  
Dirichlet Boundary Conditions ◽  
Boundary Structure ◽  
Asymptotic Symmetry ◽  
Renormalization Procedure ◽  
Field Dependent ◽  
Odd Dimensions

Abstract The gravitational charge algebra of generic asymptotically locally (A)dS spacetimes is derived in n dimensions. The analysis is performed in the Starobinsky/Fefferman-Graham gauge, without assuming any further boundary condition than the minimal falloffs for conformal compactification. In particular, the boundary structure is allowed to fluctuate and plays the role of source yielding some symplectic flux at the boundary. Using the holographic renormalization procedure, the divergences are removed from the symplectic structure, which leads to finite expressions. The charges associated with boundary diffeomorphisms are generically non-vanishing, non-integrable and not conserved, while those associated with boundary Weyl rescalings are non-vanishing only in odd dimensions due to the presence of Weyl anomalies in the dual theory. The charge algebra exhibits a field-dependent 2-cocycle in odd dimensions. When the general framework is restricted to three-dimensional asymptotically AdS spacetimes with Dirichlet boundary conditions, the 2-cocycle reduces to the Brown-Henneaux central extension. The analysis is also specified to leaky boundary conditions in asymptotically locally (A)dS spacetimes that lead to the Λ-BMS asymptotic symmetry group. In the flat limit, the latter contracts into the BMS group in n dimensions.

scholarly journals Mechanics of tubular helical assemblies: ensemble response to axial compression and extension

2021 ◽  
Author(s):  
Jacopo Quaglierini ◽  
Alessandro Lucantonio ◽  
Antonio DeSimone
Keyword(s):  
Boundary Conditions ◽  
Elastic Properties ◽  
Central Region ◽  
Mechanical Response ◽  
Different Boundary Conditions ◽  
Kirchhoff Rods ◽  
Model Versus ◽  
The Individual ◽  
Opposite Chirality

Abstract Nature and technology often adopt structures that can be described as tubular helical assemblies. However, the role and mechanisms of these structures remain elusive. In this paper, we study the mechanical response under compression and extension of a tubular assembly composed of 8 helical Kirchhoff rods, arranged in pairs with opposite chirality and connected by pin joints, both analytically and numerically. We first focus on compression and find that, whereas a single helical rod would buckle, the rods of the assembly deform coherently as stable helical shapes wound around a common axis. Moreover, we investigate the response of the assembly under different boundary conditions, highlighting the emergence of a central region where rods remain circular helices. Secondly, we study the effects of different hypotheses on the elastic properties of rods, i.e., stress-free rods when straight versus when circular helices, Kirchhoff’s rod model versus Sadowsky’s ribbon model. Summing up, our findings highlight the key role of mutual interactions in generating a stable ensemble response that preserves the helical shape of the individual rods, as well as some interesting features, and they shed some light on the reasons why helical shapes in tubular assemblies are so common and persistent in nature and technology. Graphic Abstract We study the mechanical response under compression/extension of an assembly composed of 8 helical rods, pin-jointed and arranged in pairs with opposite chirality. In compression we find that, whereas a single rod buckles (a), the rods of the assembly deform as stable helical shapes (b). We investigate the effect of different boundary conditions and elastic properties on the mechanical response, and find that the deformed geometries exhibit a common central region where rods remain circular helices. Our findings highlight the key role of mutual interactions in the ensemble response and shed some light on the reasons why tubular helical assemblies are so common and persistent.

scholarly journals A first intercomparison of the simulated LGM carbon results within PMIP-carbon: role of the ocean boundary conditions

2021 ◽  
Author(s):  
Fanny Lhardy ◽  
Nathaelle Bouttes ◽  
Didier M. Roche ◽  
Ayako Abe-Ouchi ◽  
Zanna Chase ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Ocean Boundary

Innovation in SMEs: the role of employee training in German SMEs

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Irem Demirkan ◽  
Ravi Srinivasan ◽  
Alka Nand
Keyword(s):  
Research And Development ◽  
Boundary Conditions ◽  
Product Innovation ◽  
Employee Training ◽  
Lower Proportion ◽  
Economic Research ◽  
Content Type ◽  
The Relationship ◽  
Practical Implications

PurposeThis paper explores the role of effective resource and knowledge management capabilities on product innovation capabilities of the small and medium-sized enterprises (SMEs). Specifically, the authors research the role of the human resource investments in the form of employee training in developing firm's innovation capabilities and how SMEs manage these investments when we account for the boundary conditions such as the level of employee education, SME size and the frequency of investments in research and development (R&D).Design/methodology/approachThe authors use survey data conducted by The Centre for European Economic Research (Zentrum für Europäische Wirtschaftsforschung – ZEW). The final sample for analysis includes 983 SMEs from Germany that belong to 13 different industries. The authors use hierarchical OLS regression to test the hypotheses presented in this paper.FindingsThe authors find a positive association between increased investments in employee training and product innovation capabilities in the context of SMEs. More specifically, the authors’ findings support that (1) the relationship between employee training and innovation capabilities is weaker in industries with greater proportion of employees with university degrees, (2) the effectiveness of investments in employee training is lower among larger SMEs than smaller SMEs, and (3) continuous R&D weakens the relationship between training expenditure and innovation capabilities. While on the one hand the authors’ findings contribute to the debate of whether employee training is necessary for SMEs by affirming this notion, on the other hand the authors show that investments in employee training have differing implications for small and large SMEs within boundary conditions. Moreover, these findings have practical implications for the managers of all SMEs in terms of management of their knowledge resources.Research limitations/implicationsThe authors’ research makes important contributions to the study of innovation in SMEs. First, the authors contribute evidence to the debate whether employee training is necessary for SMEs by showing that employee training is particularly important for SMEs that are smaller in size, have lower proportion of employees with university degrees and when they invest in research and development in a targeted manner. The authors also demonstrate that investments in employee training is not a waste, rather such investments can increase the likelihood of survival for many of these firms through its positive impact on product innovation.Practical implicationsFor managers of SMEs, the authors’ findings suggest that while investments in employee training are important, the managers of particular SMEs with above-mentioned qualities should be persistent in such investments and must make deliberate efforts to reap the benefits in terms of innovative capabilities. Unlike large firms, who have the financial means to carry out investments in an abundant manner, SMEs appear to be more enterprising with their scarce resources when we also consider the role of investments in human resources.Originality/valueThe authors’ research makes important contributions to the study of innovation in SMEs. First, the authors contribute evidence to the debate whether employee training is necessary for SMEs by finding that employee training is particularly important for SMEs that are smaller in size, have lower proportion of employees with university degrees and when they do not invest in R&D continuously. The authors also demonstrate that investments in employee training is not a waste, but such investments can increase the likelihood of survival for many of these firms.

Simulations of electric field at the initiation altitudes of sprites and halos generated by the thundercloud charge structure and lightning channels of causative return strokes

2021 ◽  
Author(s):  
Petr Kaspar ◽  
Ivana Kolmasova ◽  
Ondrej Santolik ◽  
Martin Popek ◽  
Pavel Spurny ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Electric Field ◽  
Boundary Conditions ◽  
Free Space ◽  
Nonlinear Effects ◽  
Charge Structure ◽  
Transient Luminous Events ◽  
Lightning Channel ◽  
Free Parameters

<p><span>Sprites and halos are transient luminous events occurring above thunderclouds. They can be observed simultaneously or they can also appear individually. Circumstances leading to initiation of these events are still not completely understood. In order to clarify the role of lightning channels of causative lightning return strokes and the corresponding thundercloud charge structure, we have developed a new model of electric field amplitudes at halo/sprite altitudes. It consists of electrostatic and inductive components of the electromagnetic field generated by the lightning channel in free space at a height of 15 km. Above this altitude we solve Maxwell’s equations self-consistently including the nonlinear effects of heating and ionization/attachment of the electrons. At the same time, we investigate the role of a development of the thundercloud charge structure and related induced charges above the thundercloud. We show how these charges lead to the different distributions of the electric field at the initiation heights of the halos and sprites. We adjust free parameters of the model using observations of halos and sprites at the Nydek TLE observatory and using measurements of luminosity curves of the corresponding return strokes measured by an array of fast photometers. The latter measurements are also used to set the boundary conditions of the model.</span></p>

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