2,983 research outputs found

    An approximate buckling analysis for rectangular orthotropic plates with centrally located cutouts

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    An approximate analysis for predicting buckling of rectangular orthotropic composite plates with centrally located cutouts is presented. In this analysis, prebuckling and buckling problems are converted from a two-dimensional to a one-dimensional system of linear differential equations with variable coefficients. The conversion is accomplished by expressing the displacements as series with each element containing a trigonometric function of one coordinate and a coefficient that is an arbitrary function of the other coordinate. Ordinary differential equations are then obtained from a variational principle. Analytical results obtained from the approximate analysis are compared with finite element analyses for isotropic plates and for specially orthotropic plates with central circular cutouts of various sizes. Experimental results for the specially orthotropic plates are also presented. In nearly all cases, the approximate analysis predicts the buckling mode shapes correctly and predicts the buckling loads to within a few percent of the finite element and experimental results

    How Was \u3cem\u3eThat\u3c/em\u3e Reasonable? The Misguided Development of Qualified Immunity and Excessive Force by Law Enforcement Officers

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    Under the qualified immunity doctrine, current policy shields law enforcement officers who utilize excessive force against ordinary American citizens. As a result, police departments and enforcement officers lack incentives to change their behavior, leaving victims and grieving families powerless in the face of an unforgiving legal doctrine that provides little to no justice. This Note explores the creation and development of the qualified immunity doctrine within the policing context and argues that its near-impossible and unjust standards have been problematically overextended and drastically need reform by the Supreme Court. The countless lives lost at the hands of those who are meant to serve and protect are not in vain—they serve as the clarion call for legal change

    The orbits of subdwarf-B + main-sequence binaries. II. Three eccentric systems; BD+29 3070, BD +34 1543 and Feige 87

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    The predicted orbital-period distribution of the subdwarf-B (sdB) population is bi-modal with a peak at short ( 250 days) periods. Observationally, many short-period sdB systems are known, but the predicted long period peak is missing as orbits have only been determined for a few long-period systems. As these predictions are based on poorly understood binary-interaction processes, it is of prime importance to confront the predictions with reliable observational data. We therefore initiated a monitoring program to find and characterize long-period sdB stars. In this paper we aim to determine the orbital parameters of the three long-period sdB+MS binaries BD+29 3070, BD+34 1543 and Feige 87, to constrain their absolute dimensions and the physical parameters of the components. High-resolution spectroscopic time series were obtained with HERMES at the Mercator telescope on La Palma, and analyzed to determine the radial velocities of both the sdB and MS components. Photometry from the literature was used to construct the spectral-energy distribution (SED) of the binaries. Atmosphere models were used to fit these SEDs and to determine the surface gravities and temperatures of both components of all systems. Spectral analysis was used to check the results of the SEDs. An orbital period of 1283 +- 63 d, a mass ratio of q = 0.39 +- 0.04 and a significant non-zero eccentricity of e = 0.15 +- 0.01 were found for BD+29 3070. For BD+34 1543 we determined P = 972 +- 2 d, q = 0.57 +- 0.01 and again a clear non-zero eccentricity of e = 0.16 +- 0.01. Last, for Feige 87 we found P = 936 +- 2 d, q = 0.55 +- 0.01 and e = 0.11 +- 0.01. BD+29 3070, BD+34 1543 and Feige 87 are long period sdB + MS binaries on clearly eccentric orbits. These results are in conflict with the predictions of stable Roche-lobe overflow models.Comment: 15 pages, 6 figures, Accepted by A&

    Buckling Imperfection Sensitivity of Axially Compressed Orthotropic Cylinders

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    Structural stability is a major consideration in the design of lightweight shell structures. However, the theoretical predictions of geometrically perfect structures often considerably over predict the buckling loads of inherently imperfect real structures. It is reasonably well understood how the shell geometry affects the imperfection sensitivity of axially compressed cylindrical shells; however, the effects of shell anisotropy on the imperfection sensitivity is less well understood. In the present paper, the development of an analytical model for assessing the imperfection sensitivity of axially compressed orthotropic cylinders is discussed. Results from the analytical model for four shell designs are compared with those from a general-purpose finite-element code, and good qualitative agreement is found. Reasons for discrepancies are discussed, and potential design implications of this line of research are discussed

    Impact of European Integration on the Functioning of the Insurance Market in Poland

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    The transformation process, that has begun 20 years ago, generated significant changes in the structure and organization of Polish economy. It stimulated development of particular market's segments, especially of the insurance sector. Poland's accession to the European Union required conformity to Its regulations, fulfillment of several conditions connected with the membership in the European Community. The purpose of this article is to present the main consequences of Poland's integration with EU in the field of insurance market. Joining the common market was an important challenge for this sector in our country.Rok 1990 stanowił początek procesu transformacji systemu społeczno - gospodarczego i ustrojowego. Ostatnie 20 lat to okres intensywnych przemian o charakterze strukturalnym i organizacyjnym, w wyniku których ukształtowały się warunki rozwoju poszczególnych segmentów systemu finansowego państwa, zwłaszcza sektora ubezpieczeń. Przystąpienie Polski do Unii Europejskiej wymagało wprowadzenia szeregu zmian, dostosowujących polski porządek prawny do uregulowań wspólnotowych regulujących funkcjonowanie rynku ubezpieczeń. Celem artykułu jest zaprezentowanie szans i zagrożeń, jakie wynikają dla tego segmentu gospodarki z przystąpienia Polski do UE. Niewątpliwie proces integracji stanowił poważne wyzwanie dla polskiego rynku ubezpieczeń

    Digital Civic Engagement and Youth Participation: Hungarian LIS Students’ Perspective of Political Information

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    Objective. The research seeks to understand, how Hungarian LIS students use social media as an avenue to express their democratic actions and how social media political information affects the youth’s trust and judgement when interacting with their close family and friends online. Methods. The study employed a quantitative approach to determine the social media engagement of the participants with close family and friends. Convenience sampling was applied in this study (Students of Library and Information Science, University, Hungary), and an online questionnaire was sent to all the potential participants (to 197 students). Results. A total of 43% participated in this research. The youth give a high level of trust to their family members and close friends even if they share, post, like, or comment on something that is different from their point-of-view in social media. Moreover, the youth have a low level of judgement towards family and close friends. Conclusions. Political participation among youth is voluntary and engagement with political information in social media is rare/low
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