Shape Control for Experimental Continuation

An experimental method has been developed to locate unstable equilibria of nonlinear structures quasi-statically. The technique involves loading a structure by application of either a force or a displacement at a main actuation point, while simultaneously controlling the overall shape using additional probe points. The method is applied to a shallow arch, and unstable segments of its equilibrium path are identified experimentally for the first time. Shape control is a fundamental building block for the experimental---as opposed to numerical---continuation of nonlinear structures, which will significantly expand our ability to measure their mechanical response.Comment: Updated Figure 6 experimental results with correct calibration factor for linear transducer. Updated Figure 6 finite element results with correct load multiplier for half-model. Updated paper text to reflect these changes. 5 pages, 6 figure

Density functional theory for a model quantum dot: Beyond the local-density approximation

We study both static and transport properties of model quantum dots, employing density functional theory as well as (numerically) exact methods. For the lattice model under consideration the accuracy of the local-density approximation generally is poor. For weak interaction, however, accurate results are achieved within the optimized effective potential method, while for intermediate interaction strengths a method combining the exact diagonalization of small clusters with density functional theory is very successful. Results obtained from the latter approach yield very good agreement with density matrix renormalization group studies, where the full Hamiltonian consisting of the dot and the attached leads has to be diagonalized. Furthermore we address the question whether static density functional theory is able to predict the exact linear conductance through the dot correctly - with, in general, negative answer.Comment: 8 page

Aspectos gerais da fotossensibilizacao hepatogena em bovinos.

A sensibilização da pele a luz devido, geralmente, a ação de certas doenças, plantas ou outras substancias, e denominada fotossensibilizacao (Stedman's Medical 1972). O primeiro registro sobre a ocorrência de fotossensibilizacao hepatogena em bovinos mantidos em pastagens de Brachiaria decumbens, na América do Sul, foi feito na Venezuela (Centro Internacional de Agricultura Tropical 1975), onde a doença ocasionou a morte de doze garrotes nos primeiros dias de pastejo. No Brasil, Hutton (s.d.lL) fez observações sobre casos desta doença no gado Nelore, em pastagens de B. decumbens, em Rio Verde de Goiás. O surto acometeu, principalmente, bezerros antes e depois da desmama. Alem desta primeira constatação, vários outros autores descreveram esta doença em bovinos em pastagem de B. decumbens.bitstream/item/138531/1/COT-19.pdfCNPG

Virtual Testing of Experimental Continuation

We present a critical advance in experimental testing of nonlinear structures. Traditional quasi-static experimental methods control the displacement or force at one or more load-introduction points on a structure. This approach is unable to traverse limit points in the control parameter, as the immediate equilibrium beyond these points is statically unstable, causing the structure to snap to another equilibrium. As a result, unstable equilibria---observed numerically---are yet to be verified experimentally. Based on previous experimental work, and a virtual testing environment developed herein, we propose a new experimental continuation method that can path-follow along unstable equilibria and traverse limit points. To support these developments, we provide insightful analogies between a fundamental building block of our technique---shape control---and analysis concepts such as the principle of virtual work and Galerkin's method. The proposed testing method will enable the validation of an emerging class of nonlinear structures that exploit instabilities for novel functionality

Multi-User Interactive TV: the Next Step in Personalization

In the past few years there has been an increasing trend towards personalization in the TV world. IMS-based IPTV is a good example of a highly personalized IPTV architecture, featuring an advanced identity management subsystem. This article studies a next step in the personalization of the television experience: concurrent use of TV services that are supported by the IMSbased IPTV system. That is, multiple users using the same television set at the same or at different times, where each user as personalized interaction with the service and content. Our analysis of IMS-based IPTV use cases shows that current architectures were not designed with concurrent use in mind. However, we demonstrate that the combination of concurrent use and personalized TV services can yield interesting and viable use cases in the areas of interactive game shows, personalized electronic program guides and channel lists, and other. Finally, an analysis of the IMS-based IPTV system and architecture shows that it has all the ingredients to implement these new concurrent TV use cases, and that the main challenges will be in the area of usability. The article concludes that personalization and concurrency are not contradictory for television services, neither from a use case perspective, nor technologically. In particular, the IMS-based IPTV system is able to facilitate an enhanced and personalized experience to concurrent TV users

Study of Hg vacancies in (Hg,Cd)Te after THM growth and post-growth annealing by positron annihilation

Positron lifetime measurements have been performed to study vacancy defects in Hg0.78Cd0.22Te. Post-growth annealing under various Hg vapour pressure conditions have been used to create a well-defined number of Hg vacancies. The sensitivity range of the positron annihilation method was found to be 1015 < cHgvac<1018 cm-3. The obtained experience has been used to investigate THM-grown single crystals. The measured longitudinal and radial dependence of the vacancy concentration can be explained by the temperature profile in the grown (Hg,Cd)Te ingots

The Constitutionality of Legislative Restrictions on the Employment Rights of Legal Resident Aliens in New York State

It is the purpose of this Note to examine the most significant statutory restrictions which remain applicable to the legal resident alien of New York. Additionally, the constitutionality of New York\u27s restrictive employment statutes will be considered

A study of the use of case work services made by mothers who referred their children to the Brockton Child Guidance Clinic

Thesis (M.S.)--Boston University, 1946. This item was digitized by the Internet Archive

Psychological Impact of Cyberbully Victimization among College Students

With the growth of technology, bullying has expanded into the technological realm. Labeled cyberbullying, individuals are utilizing technology, such as cell phones and the Internet, to bully and harass others with the intention of causing harm. Most cyberbullying research has been conducted with elementary, middle, and high school-aged students in countries such as Finland, Canada, Taiwan, and Australia. The purpose of this study was to expand prevalence, psychological impact, and coping strategy research with college-student victims of cyberbullying in the United States. 799 college students from a mid-Atlantic university were surveyed via the Internet. It was found that 8.6% of that sample endorsed being a victim of cyberbullying; 8.7% of females and 8.4% of males. On the Symptom Checklist-90-R, the 69 victims were higher than 69 matched control participants in depression, anxiety, phobic anxiety, and paranoia, as well as were elevated on global severity index and positive symptom distress index scales. Victims endorsed frequently experiencing emotional consequences, such as feeling frustrated, stressed, sad/hurt, or angry. Victims had significantly more suicidal planning and attempts, as well as suicidal ideations. They also more frequently threatened suicide than control participants. In response to cyberbully victimization, female and male victims both told someone they were being victimized, avoided friends or peers, got revenge, and stopped going to events they once enjoyed. Female victims more frequently avoided Internet/cell phones and males more frequently drank alcohol/used illegal drugs as a result of their victimization. The results of this study indicated that cyberbullying is occurring in a college sample and having a negative impact upon victims