A Quasi-3D Higher-Order Theory for Bending of FG Nanoplates Embedded in an Elastic Medium in a Thermal Environment

This paper presents the effects of temperature and the nonlocal coefficient on the bending response of functionally graded (FG) nanoplates embedded in an elastic foundation in a thermal environment. The effects of transverse normal strain, as well as transverse shear strains, are considered where the variation of the material properties of the FG nanoplate are considered only in thickness direction. Unlike other shear and deformations theories in which the number of unknown functions is five and more, the present work uses shear and deformations theory with only four unknown functions. The four-unknown normal and shear deformations model, associated with Eringen nonlocal elasticity theory, is used to derive the equations of equilibrium utilizing the principle of virtual displacements. The effects due to nonlocal coefficient, side-to-thickness ratio, aspect ratio, normal and shear deformations, thermal load and elastic foundation parameters, as well as the gradation in FG nanoplate bending, are investigated. In addition, for validation, the results obtained from the present work are compared to ones available in the literature.

Effect of Solvency and Liquidity on The Profitability of Property Companies Listed on The Sharia Stock Index 2018-2020

<p><em>This study analyzes the effect of Solvency and Liquidity on the profitability of property companies listed on the Indonesian Islamic stock index for the 2018-2020 period. This research is quantitative research with secondary data from financial reports from 2018 to 2021. Regression model analysis using Common Effect Model (CE) or Ordinary Least Square (OLS) method. The findings show that DAR has a negative effect on ROA, which explains that debt will burden the company and reduce the profit level of Islamic property companies. On the other hand, DAR has no effect on ROE because debt does not affect the value of equity owned by the company itself. DER has no effect on ROA and ROE, this is certainly contrary to the Pecking Order Theory. Current Ratio has a negative effect on ROA, this is not in accordance with </em><em>Pecking Order Theory</em><em>. Cash ratio has a positive effect on ROA and also on ROE, and is in accordance with </em><em>Pecking Order Theory</em><em>. The cash ratio as the company's ability to pay short term has a positive influence, because the company is not limited to being responsible for the environment around the company but also socially responsible to the community.</em></p><p> </p><p>Penelitian ini menganalisis pengaruh Solvabilitas dan Likuiditas terhadap profitabilitas perusahaan properti yang terdaftar di indeks saham syariah Indonesia periode 2018-2020. Penelitian ini menggunakan pendekatan kuantitatif dengan data sekunder dari laporan keuangan tahun 2018 sampai dengan tahun 2021. Analisis model regresi menggunakan metode Common Effect Model (CE) atau Ordinary Least Square (OLS). Hasil analisis menunjukkan bahwa DAR berpengaruh negatif terhadap ROA, yang menjelaskan bahwa utang akan membebani perusahaan dan mengurangi tingkat keuntungan perusahaan properti syariah. Di sisi lain, DAR tidak berpengaruh terhadap ROE karena hutang tidak mempengaruhi nilai ekuitas yang dimiliki oleh perusahaan itu sendiri. DER tidak berpengaruh terhadap ROA dan ROE, hal ini tentunya bertentangan dengan Pecking Order Theory. Besarnya ekuitas utang secara khusus tidak berdampak pada tingkat keuntungan perusahaan properti. Current Ratio berpengaruh negatif terhadap ROA, hal ini tidak sesuai dengan Stakeholder Theory. Kondisi ini menyebabkan Current Ratio berpengaruh negatif terhadap ROE. Cash ratio berpengaruh positif terhadap ROA, dimana Cash Ratio berpengaruh positif terhadap ROE, dan sesuai dengan Stakeholder Theory. Rasio kas sebagai kemampuan perusahaan untuk membayar jangka pendek memiliki pengaruh positif, karena perusahaan tidak sebatas bertanggung jawab terhadap lingkungan sekitar perusahaan tetapi juga bertanggung jawab secara sosial kepada masyarakat.</p><p><em> </em><em></em></p><br /><p class="MsoNormal" style="text-align: justify; border: none; mso-padding-alt: 31.0pt 31.0pt 31.0pt 31.0pt; mso-border-shadow: yes;"><input id="ext" type="hidden" value="1" /><input id="ext" type="hidden" value="1" /></p>

On wave propagation and free vibration of piezoelectric sandwich plates with perfect and porous functionally graded substrates

This paper aims to develop analytical solutions for wave propagation and free vibration of perfect and porous functionally graded (FG) plate structures integrated with piezoelectric layers. The effect of porosities, which occur in FG materials, is rarely reported in the literature of smart FG plates but included in the present modeling. The modified rule of mixture is therefore considered for variation of effective material properties within the FG substrate. Based on a four-variable higher-order theory, the electromechanical model of the system is established through the use of Hamilton’s principle, and Maxwell’s equation. This theory drops the need of any shear correction factor, and results in less governing equations compared to the conventional higher-order theories. Analytical solutions are applied to the obtained equations to extract the results for two investigations: (I) the plane wave propagation of infinite smart plates and (II) the free vibration of smart rectangular plates with different boundary conditions. After verifying the model, extensive numerical results are presented. Numerical results demonstrate that the wave characteristics of the system, including wave frequency and phase velocity along with the natural frequencies of its bounded counterpart, are highly influenced by the plate parameters such as power-law index, porosity, and piezoelectric characteristics.

HYPER-REF: A General Model of Reference for First-Order Logic and First-Order Arithmetic

In this article I present HYPER-REF, a model to determine the referent of any given expression in First-Order Logic (FOL). I also explain how this model can be used to determine the referent of a first-order theory such as First-Order Arithmetic (FOA). By reference or referent I mean the non-empty set of objects that the syntactical terms of a well-formed formula (wff) pick out given a particular interpretation of the language. To do so, I will first draw on previous work to make explicit the notion of reference and its hyperintensional features. Then I present HYPER-REF and offer a heuristic method for determining the reference of any formula. Then I discuss some of the benefits and most salient features of HYPER-REF, including some remarks on the nature of self-reference in formal languages.

DETERMINANTES DE ESTRUTURA DE CAPITAL DE EMPRESAS DE CAPITAL ABERTO DO SETOR ELÉTRICO NO BRASIL: UMA ABORDAGEM BASEADA NA TRADE-OFF THEORY E NA PECKING ORDER THEORY

O objetivo deste trabalho foi avaliar os determinantes de estrutura de capital das empresas de capital aberto do setor elétrico brasileiro, listadas na Bolsa de Valores de São Paulo, em relação ao endividamento de curto prazo, longo prazo e geral. Foi coletada uma amostra composta por dados contábeis anuais de 80 empresas privadas e estatais, atuantes no setor elétrico brasileiro entre 2009 e 2019, empregando-se o método de regressões lineares múltiplas, com dados em painel, usando efeitos fixos e efeitos aleatórios. Os resultados apontaram que os determinantes de estrutura de capital lucratividade, oportunidade de crescimento e liquidez tiveram comportamento melhor alinhados à POT, ao passo que o risco se apresentou melhor explicado pela TOT e pela POT.

2D PROBLEM FOR A SPHERE IN THE FRACTIONAL ORDER THEORY THERMOELASTICITY TO AXISYMMETRIC TEMPERATURE DISTRIBUTION

In the present article, we implement the fractional thermoelasticity theory to a 2D issue for a sphere whose surface is free from traction, subject to a provided axisymmetric temperature distribution of heat. The medium is supposed to be quiescent initially. A direct method is used to get a solution and the Laplace transform technique is used. Mathematical models for copper material are designed as a particular instance. Numerical results are computed with help of Mathcad software and graphically represented and the fractional-order parameter effect has been explained.

Vibrations of a Cylindrical Sandwich Shell with a Honeycomb Core Made Using FDM technology

Presented is a model of the dynamic deformation of a three-layer cylindrical shell with a honeycomb core, manufactured by fused deposition modeling (FDM), and skins reinforced with oriented carbon nano-tubes (CNT). A ULTEM 9085 thermoplastic-based honeycomb core is considered. To analyze the stress-strain state of the honeycomb core, a finite element homogenization procedure was used. As a result of this procedure, the dynamic response of the honeycomb core is modeled by a homogeneous orthotropic material, whose mechanical properties correspond to those of the core. The proposed model is based on the high-order theory, extended for the analysis of sandwich structures. The skin displacement projections are expanded along the transverse coordinate up to quadratic terms. The honeycomb core displacement projections are expanded along the transverse coordinate up to cubic terms. To ensure the integrity of the structure, shell displacement continuity conditions at the junction of the layers are used. The investigation of linear vibrations of the shell is carried out using the Rayleigh-Ritz method. For its application, the potential and kinetic energies of the structure are derived. Considered are the natural frequencies and modes of vibrations of a one-side clamped cylindrical sandwich shell. The dependence of the forms and frequencies of vibrations on the honeycomb core thickness and the direction of reinforcement of the shell skins have been investigated. It was found that the eigenforms of a sandwich shell are characterized by a smaller number of waves in the circumferential direction, as well as a much earlier appearance of axisymmetric forms. This means that when analyzing the resonant vibrations of a sandwich shell, it is necessary to take into account axisymmetric shapes. Changing the direction of reinforcement of the skins with CNTs makes it possible to significantly influence the frequencies of the natural vibrations of the shell, which are characterized by a nonzero number of waves in the circumferential direction. It was found that this parameter does not affect the frequencies of the axisymmetric shapes of the shell under consideration.

Capital Structure and Debt Maturity in Nonprofit Organizations

This article examines the capital structure and debt maturity in nonprofit organizations (NPOs). In particular, we analyze whether these financing decisions are made as expected according to the two main theories used to explain the capital structure, that is, the trade-off and pecking order theories. To do so, we study the associations between NPOs’ indebtedness and their size, age, tangibility, liquidity, profitability, risk, and growth. We use fixed effects, probit, and Heckman selection models with unbalanced panel data containing 8,721 charities in the United Kingdom for the period 2011–2018 (60,222 year-obs). Our results show that the financing patterns of NPOs are consistent with the arguments of the pecking order theory. We also find that less than half of our sample uses long-term debt. Moreover, debt maturity is longer in larger NPOs, those with more tangible assets, or those with higher liquidity.

Channel-Supermodular Entropies: Order Theory and an Application to Query Anonymization

This work introduces channel-supermodular entropies, a subset of quasi-concave entropies. Channel-supermodularity is a property shared by some of the most commonly used entropies in the literature, including Arimoto–Rényi conditional entropies (which include Shannon and min-entropy as special cases), k-tries entropies, and guessing entropy. Based on channel-supermodularity, new preorders for channels that strictly include degradedness and inclusion (or Shannon ordering) are defined, and these preorders are shown to provide a sufficient condition for the more-capable and capacity ordering, not only for Shannon entropy but also regarding analogous concepts for other entropy measures. The theory developed is then applied in the context of query anonymization. We introduce a greedy algorithm based on channel-supermodularity for query anonymization and prove its optimality, in terms of information leakage, for all symmetric channel-supermodular entropies.