An Empirical Research Agenda for the Forensic Sciences

After the National Academy of Sciences issued a stunning report in 2009 on the unscientific state of many forensic science subfields, forensic science has undergone internal and external scrutiny that it had managed to avoid for decades. Although some reform efforts are underway, forensic science writ large has yet to embrace and settle upon an empirical research agenda that addresses knowledge gaps pertaining to the reliability of its methods. Our paper addresses this problem by proposing a preliminary set of fourteen empirical studies for the forensic sciences. Following a brief discussion of the courtroom treatment of forensic science evidence, we sketch a series of studies that should be conducted to increase understanding of what forensic examiners are doing, how accurately they are doing it, and how cognitive bias may affect the work product. We also propose several studies that examine how the specific questions examiners are asked might affect the validity and persuasiveness of examiners’ responses. We conclude by affirming the importance of developing a research culture within the forensic sciences that includes a commitment to conducting, participating in, and relying upon high quality empirical research

Molecular-level simulations of turbulence and Its decay

We provide the first demonstration that molecular-level methods based on gas kinetic theory and molecular chaos can simulate turbulence and its decay. The direct simulation Monte Carlo (DSMC) method, a molecular-level technique for simulating gas flows that resolves phenomena from molecular to hydrodynamic (continuum) length scales, is applied to simulate the Taylor-Green vortex flow. The DSMC simulations reproduce the Kolmogorov − 5 / 3 law and agree well with the turbulent kinetic energy and energy dissipation rate obtained from direct numerical simulation of the Navier-Stokes equations using a spectral method. This agreement provides strong evidence that molecular-level methods for gases can be used to investigate turbulent flows quantitatively

Gas-kinetic simulation of sustained turbulence in minimal Couette flow

We provide a demonstration that gas-kinetic methods incorporating molecular chaos can simulate the sustained turbulence that occurs in wall-bounded turbulent shear flows. The direct simulation Monte Carlo method, a gas-kinetic molecular method that enforces molecular chaos for gas-molecule collisions, is used to simulate the minimal Couette flow at Re=500. The resulting law of the wall, the average wall shear stress, the average kinetic energy, and the continually regenerating coherent structures all agree closely with corresponding results from direct numerical simulation of the Navier-Stokes equations. These results indicate that molecular chaos for collisions in gas-kinetic methods does not prevent development of molecular-scale long-range correlations required to form hydrodynamic-scale turbulent coherent structures

DSMC simulations of turbulent flows at moderate Reynolds numbers

The Direct Simulation Monte Carlo (DSMC) method has been used for more than 50 years to simulate rarefied gases. The advent of modern supercomputers has brought higher-density near-continuum flows within range. This in turn has revived the debate as to whether the Boltzmann equation, which assumes molecular chaos, can be used to simulate continuum flows when they become turbulent. In an effort to settle this debate, two canonical turbulent flows are examined, and the results are compared to available continuum theoretical and numerical results for the Navier-Stokes equations

O ensino de Relações Internacionais e o cinema: reflexões sobre o uso de filmes como uma ferramenta pedagógica

This article evaluates the potentials and limits of using films to teach International Relations by taking into account the perception achieved by students from two different classes in Brazil, one from the Federal University of Uberlândia (MG) and another from the University Vila Velha (ES). Among the several conclusions, the most substantial one is that films ”“ even the most didactic ones, such as documentaries ”“ require some mediation by professor(s) in order to organize and enable learning.O artigo avalia vantagens e limites do uso de filmes no ensino de Relações Internacionais a partir da percepção dos estudantes de duas turmas, uma da Universidade Federal de Uberlândia (MG) e outra da Universidade Vila Velha (ES). Extraem-se diversas conclusões, e a mais substantiva é que os filmes, mesmo os mais didáticos, como documentários, exigem a mediação docente para organizar e viabilizar a aprendizagem

Electronic structure of NiS1−x_{1-x}Sex_x across the phase transition

We report very highly resolved photoemission spectra of NiS(1-x)Se(x) across the so-called metal-insulator transition as a function of temperature as well as composition. The present results convincingly demonstrate that the low temperature, antiferromagnetic phase is metallic, with a reduced density of states at E$_F$. This decrease is possibly due to the opening of gaps along specific directions in the Brillouin zone caused by the antiferromagnetic ordering.Comment: Revtex, 4 pages, 3 postscript figure

Alephnull-Extended Supersymmetric Chern-Simons Theory for Arbitrary Gauge Groups

We present a model of supersymmetric non-Abelian Chern-Simons theories in three-dimensions with arbitrarily many supersymmetries, called alephnull-extended supersymmetry. The number of supersymmetry N equals the dimensionality of any non-Abelian gauge group G as N = dim G. Due to the supersymmetry parameter in the adjoint representation of a local gauge group G, supersymmetry has to be local. The minimal coupling constant is to be quantized, when the homotopy mapping is nontrivial: \pi_3(G) = Z. Our results indicate that there is still a lot of freedom to be explored for Chern-Simons type theories in three dimensions, possibly related to M-theory.Comment: 6 pages, no figur

Sensitivity and Estimation of Flying-Wing Aerodynamic, Propulsion, and Inertial Parameters Using Simulation

This paper explores the difficulties of aircraft system identification, specifically parameter estimation, for a rudderless aircraft. A white box method is used in conjunction with a nonlinear six degree-of-freedom aerodynamic model for the equations of motion in order to estimate 33 parameters that govern the aerodynamic, inertial, and propulsion forces within the mathematical model. The analysis is conducted in the time-domain of system identification. Additionally, all the parameters are estimated using a single flight rather than a series of shorter flights dedicated to estimating specific sets of parameters as is typically done. A final flight plan is developed with a mixture of lateral maneuvers interspersed throughout the flight to accentuate the significance of the lateral parameters during estimation. Certain parameters were ill-conditioned for parameter estimation using the mathematical model and final flight plan derived in this paper. The gradient-based optimization technique used in the estimation algorithm struggled to accurately estimate all 33 in a single flight due to the abundance of local minima within the solution space. The results of this work may provide a few insights for parameter estimation. First, to understand why system identification is performed the way it is currently done through multiple different flight maneuvers. Second, to gain some visual insight to the behavior of the nonlinear six degree-of-freedom aerodynamic model that describes the motion of fixed wing aircraft. This work may also be helpful in determining which parameters might likely be estimated together and which may struggle due to coupled dynamic relations within the mathematical model

DOSES E FORMAS DE APLICAÇÃO DE POTÁSSIO NA CULTURA DO FEIJOEIRO EM SISTEMA DE PLANTIO DIRETO NA PALHA

In 1997/98 and 1998/99 experiments were implanted in field in Tibagi, PR, to evaluate the answer of the common beans at the different potassium rates (0, 30, 60, 90 and 120 kg ha-1 of K2O) and two application forms (line and throw), in Cultivar Carioca in notillsystem. The experiment was installed in randomized blocks in  arrangement factorial 2x5 with four replications. In the stages R5, R6,R7, R8 e R9 they were used ten plants and evaluated dry mass. The leaves of twenty plants were collected to observe the potassium levelin the leaf tissue. In the two years of evaluation, the culture didn’t answer to the different potassium doses and the two application forms to the yield and its components, showing that, even for high yields, favorable climatic conditions, the plant supplies its need for the element in the soil, due constant replacement of the cultures predecessors, cultural remains.Em 1997/98 e 1998/99 foram implantados experimentos de campo em Tibagi, PR, com o objetivo de avaliar a resposta dacultura do feijão, cultivar Carioca a diferentes doses de potássio (0, 30, 60, 90 e 120 kg ha-1 de K2O) e em duas formas de aplicação (linha e lanço) em sistema de plantio direto na palha. O delineamento experimental foi o de blocos ao acaso em arranjo fatorial 2x5 em quatro repetições. Nos estádios R5, R6, R7, R8 e R9 foram amostradas dez plantas para avaliação da massa seca. Foram coletadas folhas de vinte plantas para ser observado o teor de potássio no tecido foliar. Nos dois anos de avaliação a cultura não respondeu a diferentes doses de potássio e às formas de aplicação para o rendimento e seus componentes, mostrando que mesmo para altas produtividades e com as condições climáticas favoráveis a reserva do solo supriu a sua necessidade da planta deste elemento, que foi formada pela constante reposição dos restos culturais das culturas antecessoras