On the Consistency of Perturbativity and Gauge Coupling Unification

We investigate constraints that the requirements of perturbativity and gauge coupling unification impose on extensions of the Standard Model and of the MSSM. In particular, we discuss the renormalization group running in several SUSY left-right symmetric and Pati-Salam models and show how the various scales appearing in these models have to be chosen in order to achieve unification. We find that unification in the considered models occurs typically at scales below M^{min}_{B violation} = 10^16 GeV, implying potential conflicts with the non-observation of proton decay. We emphasize that extending the particle content of a model in order to push the GUT scale higher or to achieve unification in the first place will very often lead to non-perturbative evolution. We generalize this observation to arbitrary extensions of the Standard Model and of the MSSM and show that the requirement of perturbativity up to M^{min}_{B violation}, if considered a valid guideline for model building, severely limits the particle content of any such model, especially in the supersymmetric case. However, we also discuss several mechanisms to circumvent perturbativity and proton decay issues, for example in certain classes of extra dimensional models.Comment: LaTeX, 20 pages, 8 figures, 1 tabl

The omnivorous Tyrolean Iceman: colon contents (meat, cereals, pollen, moss and whipworm) and stable isotope analyses

The contents of the colon of the Tyrolean Iceman who lived Ga. 5300 years ago include muscle fibres, cereal remains, a diversity of pollen, and most notably that of the hop hornbeam (Ostrya carpinifolia) retaining cellular contents, as well as a moss leaf (Neckera complanata) and eggs of the parasitic whipworm (Trichuris trichiura). Based almost solely on stable isotope analyses and ignoring the work on the colon contents, two recently published papers on the Iceman's diet draw ill- founded conclusions about vegetarianism and even veganism. Neither the pollen nor the moss is likely to have been deliberately consumed as food by the Iceman. All the available evidence concerning the Iceman's broad-based diet is reviewed and the significance of the colon contents for matters other than assessment of food intake is outlined

An accurate analytic description of neutrino oscillations in matter

A simple closed-form analytic expression for the probability of two-flavour neutrino oscillations in a matter with an arbitrary density profile is derived. Our formula is based on a perturbative expansion and allows an easy calculation of higher order corrections. The expansion parameter is small when the density changes relatively slowly along the neutrino path and/or neutrino energy is not very close to the Mikheyev-Smirnov-Wolfenstein (MSW) resonance energy. Our approximation is not equivalent to the adiabatic approximation and actually goes beyond it. We demonstrate the validity of our results using a few model density profiles, including the PREM density profile of the Earth. It is shown that by combining the results obtained from the expansions valid below and above the MSW resonance one can obtain a very good description of neutrino oscillations in matter in the entire energy range, including the resonance region.Comment: 16 pages,6 figure

Construction of an Instrumentation Kit for Identification and Control of DC Motors

This paper presents the development of an instrumentation kit of voltage and current measurement for identification of the dynamic model and control of direct current (DC) motors. In the methodology for the parameters identification is used the responses of input voltage and current, and angular velocity of the DC motor. The validation of the obtained dynamic model is done through the comparison of the simulated and experimental responses, and the application of a control system based on state feedback and complete eigenstructure assignment (tracking system). The responses are compared through the normalized root-mean-square error criterion

Control of a Modified Ball and Beam System Using Tracking System in Real Time with a DC Motor as an Actuator

This paper presents amodified ball and beam system, with the intention of realizing a test bed, to study new control techniques in real-time.The ball and beam system consists of a ball over a long beam where the control objective is to stabilizethe position of the ball on the beam by changing the angular position of the beam.In this paper, the ball of the conventional system is replaced by a cart with an embedded microcontroller, enabling the use of a linear encoder as position sensor and allowing to transmit the position via RF (Radio Frequency). The mathematical model of the ball and beam is obtained through the equations of Newton-Euler and the equations were linearized. The system is controlled using the hardware-in-the-loop technique with MATLAB/Simulink.It is applied a tracking control system with entire eigenstructure assignment to control the position of the cart. The actuator used is a DC motor, and a PID(proportional, integral and derivative) control is used to perform the angular position control of beam.The simulation results and the experimental results are compared to validate the mathematical model. The results obtained were satisfactory with adequate accuracy

Virtual Prototyping, Identification and Control of a Twin Rotor with 3DOF

This paper presents a methodology for identification of the physical characteristics, generation of the mathematical model through virtual prototyping and control of the didactic plant of a twin rotor. In the identification of the physical characteristics, the centers of mass and moments of inertia of the twin rotor parts were identified separately, by means of an easel designed for such task. Still in the identification of the physical characteristics, the equation that relates the applied voltage in the direct current motor with the thrust force produced by the propellers was obtained. The mathematical model of the twin rotor was obtained by means of the identification of the physical characteristics allied to the virtual prototyping with the aid of ADAMS and SolidWorks software. The implemented control system uses state feedback and complete eigenstructure assignment. The ease and usefulness of the proposed methodology was presented through the plant instrumentation, simulation and control in MATLAB/Simulink environment

Generation of the Becker muscular dystrophy patient derived induced pluripotent stem cell line carrying the DMD splicing mutation c.1705-8 T>C

Becker Muscular dystrophy (BMD) is an X-linked syndrome characterized by progressive muscle weakness. BMD is generally less severe than Duchenne Muscular Dystrophy. BMD is caused by mutations in the dystrophin gene that normally give rise to the production of a truncated but partially functional dystrophin protein. We generated an induced pluripotent cell line from dermal fibroblasts of a BMD patient carrying a splice mutation in the dystrophin gene (c.1705-8 T>C). The iPSC cell-line displayed the characteristic pluripotent-like morphology, expressed pluripotency markers, differentiated into cells of the three germ layers and had a normal karyotype

Parameters Identification of a Direct Current Motor Using the Trust Region Algorithm

In this paper, the trust region algorithm was used to identify the parameters of the dynamic model of a permanent magnet direct current (PMDC) motor, using the MATLAB/Simulink Parameter Estimation tool. The objective was to estimate the parameters applying the square wave, pseudo-random binary sequence (PRBS) and random signals in the motor excitation. The obtained models were evaluated in open and closed loop, where a speed control project was applied using the entire eigenstructure assignment. The error between the simulated and real curves of velocity and current were evaluated by means of the normalized root mean squared error (NRMSE)