Unitarity and nonrelativistic potential energy in a higher-order Lorentz symmetry breaking electromagnetic model

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Lorentz-violating effects in three-dimensional QED

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Transformações de Lorentz e seus invariantes

In this paper, we will show the types of Lorentz transformations, from the most described in books, special Lorentz transformation that relates two inertial systems whose relative velocities are directed along an axis of the respective bases systems. However, we will see a peculiarity that goes unnoticed in this transformation, although they have reported in many books a parallel between the transformation inertial systems, due to the fact that the speed is parallel to an axis, it is actually a semi-parallel processing. The next transformation that we will see is one in which a system moves with a relative speed that has arbitrary direction with respect to a given system, we will show that this transformation may be appointed as non-rotational Lorentz transformation. Before obtain, the later type of transformation, the rotational Lorentz transformation, which is the interface between Special Relativity and General Relativity, we will describe the systems to be rotated, not just inertial systems, show what the characteristics are that define the non-rotational and rotational transformations. The in last topic of this chapter we will also show how the idea of Thoma’s theorythat uses this transformation to create what he defines as the proper coordinate axes of the particleused to obtain the factor 1/2 electron spin. In the last chapter we show how the Lorentz invariants are obtained, quantities measures that are also in different Lorentz reference, with the focus on mass that has erroneously been described in many books, that varies according to the agreement reference system

Efeito de reguladores vegetais no desenvolvimento de plantas jovens de Tabebuia avellanedae Lorentz ex Griseb

Tabebuia avellanedae Lorentz ex Griseb (ipê-roxo), Bignoniaceae, ocorre na Floresta Tropical Atlântica e é de grande importância, uma vez que, devido às suas propriedades medicinais e lenho de grande valor comercial, já esteve sob ameaça de extinção. A mistura de reguladores vegetais é conhecida como bioestimulante que pode incrementar o desenvolvimento vegetal, estimulando a divisão, a diferenciação e o alongamento celular. Assim, neste trabalho avaliou o efeito da aplicação da mistura de reguladores vegetais do grupo das auxinas, giberelinas e citocininas no desenvolvimento de plantas jovens de ipê-roxo. Os tratamentos foram: testemunha, GA4+7 + BAP 100 mg L-1, GA4+7 + BAP 200 mg L-1, GA3 + IBA + cinetina 0,5% e GA3 + IBA + cinetina 1,0% os quais foram aplicados 4 vezes em intervalos de 30 dias. O efeito dos tratamentos foi avaliado pelas medidas de altura das plantas, diâmetro do caule, número de folhas, massa seca das folhas, caule e raízes e avaliação de trocas gasosas. O tratamento com GA3 + BAP 200 mg L-1 foi aquele que apresentou maior efeito no crescimento das plantas. Já para as avaliações fotossintéticas o tratamento com GA3 + IBA + cinetina foi aquele que apresentou a maior taxa de assimilação de CO2

Axial loads on implant-supported partial fixed prostheses for external and internal hex connections and machined and plastic copings: strain gauge analysis

The aim of this in vitro study was to use strain gauge (SG) analysis to compare the effects of the implant-abutment joint, the coping, and the location of load on strain distribution in the bone around implants supporting 3-unit fixed partial prostheses. Three external hexagon (EH) implants and 3 internal hexagon (IH) implants were inserted into 2 polyurethane blocks. Microunit abutments were screwed onto their respective implant groups. Machined cobalt-chromium copings and plastic copings were screwed onto the abutments, which received standard wax patterns. The wax patterns were cast in a cobalt-chromium alloy (n = 5): group 1 = EH/machined. group 2 = EH/plastic, group 3 = IH/machined, and group 4 = IH/plastic. Four SGs were bonded onto the surface of the block tangentially to the implants. Each metallic structure was screwed onto the abutments and an axial load of 30 kg was applied at 5 predetermined points. The magnitude of microstrain on each SG was recorded in units of microstrain (mu epsilon). The data were analyzed using 3-factor repeated measures analysis of variance and a Tukey test (alpha = 0.05). The results showed statistically significant differences for the type of implant-abutment joint, loading point, and interaction at the implant-abutment joint/loading point. The IH connection showed higher microstrain values than the EH connection. It was concluded that the type of coping did not interfere in the magnitude of microstrain, but the implant/abutment joint and axial loading location influenced this magnitude.

Stress distribution around osseointegrated implants with different internal-cone connections: photoelastic and finite element analysis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Coupled scalar fields oscillons and breathers in some lorentz violating scenarios

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Entropic information for travelling solitons in Lorentz and CPT breaking systems

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Connections Between Communication and Math Abilities

In this action research study of my Class I School’s 5th and 8th grade mathematics, I investigated students’ connections between communication of math skills and their math abilities. I discovered that students can increase their math abilities with the opportunities to discuss their thinking as well as evaluate thinking and strategies of other students. Electronic communication can be a valuable source for students to communicate further to other students.

Journal Writing in Mathematics: Exploring the Connections between Math Journals and the Completion of Homework Assignments

In this action research study of sixth grade mathematics, I investigate how the use of written journals facilitates the learning of mathematics for my students. I explore furthermore whether or not these writing journals support students to complete their homework. My analysis reveals that while students do not access their journals daily, when students have the opportunity to write more about one specific problem--such as finding the relationship between the area of two different sized rectangles – they, are nevertheless, more likely to explain their thoughts in-depth and go beyond the traditional basic steps to arrive at a solution. This suggests the value of integrating journal writing in a math curriculum as it can facilitate classroom discussion from the students’ written work.

Using Non-Traditional Activities to Enhance Mathematical Connections

In this action research study of my classroom of seventh grade mathematics, I investigated the use of non-traditional activities to enhance mathematical connections. The types of nontraditional activities used were hands-on activities, written explanations, and oral communication that required students to apply a new mathematical concept to either prior knowledge or a realworld application. I discovered that the use of non-traditional activities helped me reach a variety of learners in my classroom. These activities also increased my students’ abilities to apply their mathematical knowledge to different applications. Having students explain their reasoning during non-traditional activities improved their communications skills, both orally and in writing. As a result of this research, I plan to incorporate more non-traditional activities into my curriculum. In doing so, I hope to continue to increase my students’ abilities to solve problems. I also plan to incorporate the use of written explanations of my students’ mathematical reasoning in order to continue to improve their communication of mathematics.

Leakage of Saliva Through the Implant-Abutment Interface: In Vitro Evaluation of Three Different Implant Connections Under Unloaded and Loaded Conditions

Purpose: Bacterial leakage along the implant-abutment interface, with consequent species harboring the inner parts of two-part dental implant systems, has been reported in the literature. The aim of this in vitro study was to evaluate bacterial leakage from human saliva to the internal part of the implants along the implant-abutment interface under loaded and unloaded conditions using DNA Checkerboard. Materials and Methods: Sixty denial implants-20 each of external-hexagon, internal-hexagon, and Morse cone-connection designs-and their conical abutments were used in this study. Each group was subdivided into two groups of 10 loaded and 10 unloaded implants. The assemblies were immersed in human saliva and either (1) loaded with 500,000 cycles at 120 N (experimental group) or (2) incubated in static conditions for 7 days at 35 degrees C (unloaded control group). Results: Microorganisms were found in the internal surfaces of all types of connections. The Morse cone connection presented the lowest count of microorganisms in both the unloaded and loaded groups. Loaded implants presented with higher counts of microorganisms than unloaded implants for external- and internal-hex connections. Conclusion: Bacterial species from human saliva may penetrate along the implant-abutment interface under both unloaded and loaded conditions for all connections evaluated. Morse cone-connection implants showed the lowest counts of microorganisms for both conditions. External- and internal-hex implants showed a higher incidence of bacteria and higher bacterial counts after simulated loading. INT J ORAL MAXILLOFAC IMPLANTS 2012;27:551-560.

Effects of a CPT-even and Lorentz-violating nonminimal coupling on electron-positron scattering

We propose a new CPT-even and Lorentz-violating nonminimal coupling between fermions and Abelian gauge fields involving the CPT-even tensor (K-F)(mu nu alpha beta) of the standard model extension. We thus investigate its effects on the cross section of the electron-positron scattering by analyzing the process e(+) + e(-) -> mu(+) + mu(-). Such a study was performed for the parity-odd and parity-even nonbirefringent components of the Lorentz-violating (K-F)(mu nu alpha beta) tensor. Finally, by using experimental data available in the literature, we have imposed upper bounds as tight as 10(-12) (eV)(-1) on the magnitude of the CPT-even and Lorentz-violating parameters while nonminimally coupled. DOI: 10.1103/PhysRevD.86.125033

Connections between the Sznajd model with general confidence rules and graph theory

The Sznajd model is a sociophysics model that is used to model opinion propagation and consensus formation in societies. Its main feature is that its rules favor bigger groups of agreeing people. In a previous work, we generalized the bounded confidence rule in order to model biases and prejudices in discrete opinion models. In that work, we applied this modification to the Sznajd model and presented some preliminary results. The present work extends what we did in that paper. We present results linking many of the properties of the mean-field fixed points, with only a few qualitative aspects of the confidence rule (the biases and prejudices modeled), finding an interesting connection with graph theory problems. More precisely, we link the existence of fixed points with the notion of strongly connected graphs and the stability of fixed points with the problem of finding the maximal independent sets of a graph. We state these results and present comparisons between the mean field and simulations in Barabasi-Albert networks, followed by the main mathematical ideas and appendices with the rigorous proofs of our claims and some graph theory concepts, together with examples. We also show that there is no qualitative difference in the mean-field results if we require that a group of size q > 2, instead of a pair, of agreeing agents be formed before they attempt to convince other sites (for the mean field, this would coincide with the q-voter model).

Lorentz violation bounds on Bhabha scattering

We investigate the effect of Lorentz-violating terms on Bhabha scattering in two distinct cases correspondent to vectorial and axial nonminimal couplings in quantum electrodynamics ( QED). In both cases, we find significant modifications with respect to the usual relativistic result. Our results reveal an anisotropy of the differential cross section which implies new constraints on the possible Lorentz-violating terms.