The inner Cauchy horizon of axisymmetric and stationary black holes with surrounding matter in Einstein-Maxwell theory

We study the interior electrovacuum region of axisymmetric and stationary black holes with surrounding matter and find that there exists always a regular inner Cauchy horizon inside the black hole, provided the angular momentum J and charge Q of the black hole do not vanish simultaneously. In particular, we derive an explicit relation for the metric on the Cauchy horizon in terms of that on the event horizon. Moreover, our analysis reveals the remarkable universal relation (8\pi J)2+(4\pi Q2)2=A+ A-, where A+ and A- denote the areas of event and Cauchy horizon respectively

Universal properties of distorted Kerr-Newman black holes

We discuss universal properties of axisymmetric and stationary configurations consisting of a central black hole and surrounding matter in Einstein-Maxwell theory. In particular, we find that certain physical equations and inequalities (involving angular momentum, electric charge and horizon area) are not restricted to the Kerr-Newman solution but can be generalized to the situation where the black hole is distorted by an arbitrary axisymmetric and stationary surrounding matter distribution.Comment: 7 page

Differences in Thermal Stability of Glucosinolates in Five Brassica Vegetables

The thermal stability of individual glucosinolates within five different Brassica vegetables was studied at 100°C for different incubation times up to 120 minutes. Three vegetables that were used in this study were Brassica oleracea (red cabbage, broccoli and Brussels sprouts) and two were Brassica rapa (pak choi and Chinese cabbage). To rule out the influence of enzymatic breakdown, myrosinase was inactivated prior to the thermal treatments. The stability of three glucosinolates that occurred in all five vegetables (gluconapin, glucobrassicin and 4-methoxyglucobrassicin) varied considerably between the different vegetables. The degradation could be modeled by first order kinetics. The rate constants obtained varied between four to twenty fold between the five vegetables. Brussels sprouts showed the highest degradation rates for all three glucosinolates. The two indole glucosinolates were most stable in red cabbage, while gluconapin was most stable in broccoli. These results indicate the possibilities for plant breeding to select for cultivars in which glucosinolates are more stable during processin

A method to correct differential nonlinearities in subranging analog-to-digital converters used for digital gamma-ray spectroscopy

The influence on $\gamma$-ray spectra of differential nonlinearities (DNL) in subranging, pipelined analog-to-digital converts (ADCs) used for digital $\gamma$-ray spectroscopy was investigated. The influence of the DNL error on the $\gamma$-ray spectra, depending on the input count-rate and the dynamic range has been investigated systematically. It turned out, that the DNL becomes more significant in $\gamma$-ray spectra with larger dynamic range of the spectroscopy system. An event-by-event offline correction algorithm was developed and tested extensively. This correction algorithm works especially well for high dynamic ranges

The interior of axisymmetric and stationary black holes: Numerical and analytical studies

We investigate the interior hyperbolic region of axisymmetric and stationary black holes surrounded by a matter distribution. First, we treat the corresponding initial value problem of the hyperbolic Einstein equations numerically in terms of a single-domain fully pseudo-spectral scheme. Thereafter, a rigorous mathematical approach is given, in which soliton methods are utilized to derive an explicit relation between the event horizon and an inner Cauchy horizon. This horizon arises as the boundary of the future domain of dependence of the event horizon. Our numerical studies provide strong evidence for the validity of the universal relation \Ap\Am = (8\pi J)^2 where \Ap and \Am are the areas of event and inner Cauchy horizon respectively, and $J$ denotes the angular momentum. With our analytical considerations we are able to prove this relation rigorously.Comment: Proceedings of the Spanish Relativity Meeting ERE 2010, 10 pages, 5 figure

Modeling the thermal evolution of enzyme-created bubbles in DNA

The formation of bubbles in nucleic acids (NAs) are fundamental in many biological processes such as DNA replication, recombination, telomeres formation, nucleotide excision repair, as well as RNA transcription and splicing. These precesses are carried out by assembled complexes with enzymes that separate selected regions of NAs. Within the frame of a nonlinear dynamics approach we model the structure of the DNA duplex by a nonlinear network of coupled oscillators. We show that in fact from certain local structural distortions there originate oscillating localized patterns, that is radial and torsional breathers, which are associated with localized H-bond deformations, being reminiscent of the replication bubble. We further study the temperature dependence of these oscillating bubbles. To this aim the underlying nonlinear oscillator network of the DNA duplex is brought in contact with a heat bath using the Nos$\rm{\acute{e}}$-Hoover-method. Special attention is paid to the stability of the oscillating bubbles under the imposed thermal perturbations. It is demonstrated that the radial and torsional breathers, sustain the impact of thermal perturbations even at temperatures as high as room temperature. Generally, for nonzero temperature the H-bond breathers move coherently along the double chain whereas at T=0 standing radial and torsional breathers result.Comment: 19 pages, 7 figure

Magnetic Phase Diagrams of Manganites-like Local-Moment Systems with Jahn-Teller distortions

We use an extended two-band Kondo lattice model (KLM) to investigate the occurrence of different (anti-)ferromagnetic phases or phase separation depending on several model parameters. With regard to CMR-materials like the manganites we have added a Jahn-Teller term, direct antiferromagnetic coupling and Coulomb interaction to the KLM. The electronic properties are self-consistently calculated in an interpolating self-energy approach with no restriction to classical spins and going beyond mean-field treatments. Further on we do not have to limit the Hund's coupling to low or infinite values. Zero-temperature phase diagrams are presented for large parameter intervals. There are strong influences of the type of Coulomb interaction (intraband, interband) and of the important parameters (Hund's coupling, direct antiferromagnetic exchange, Jahn-Teller distortion), especially at intermediate couplings.Comment: 11 pages, 9 figures. Accepted for publication in Phys. Rev.

MEASUREMENT AND EVALUATION OF LOADS ON THE HUMAN BODY DURING SPORTS ACTIVITIES

Introduction: Mechanical loads on the human body are necessary to stimulate bone growth, to maintain bone integrity, and to strengthen the skeletal musculature. However, excessive forces, repetitive shock and high pressures have been identified as contributors to traumatic and overuse injuries. For events of short duration, cinematographic techniques are normally not sufficient to estimate the forces and accelerations experienced by the body's center of mass (CoM) or any one of its parts. Therefore, mechanical sensors are necessary to register forces, accelerations and pressure distributions that occur during sports activities. This methodological overview concentrates on technological aspects and the application of force, pressure and acceleration measurements. Methods: In the field of biomechanics piezoelectric and strain gage force platforms are commonly used for the determination of ground reaction forces. Properly mounted, these measuring devices provide high accuracy and a good frequency response. Desirable transducer characteristics for biomechanical applications may differ from characteristics advantageous for engineering usage. Measurement of pressure during sitting or lying on a bed requires a soft and pliable transducer mat that will adapt to the shape of the human body. However, such a transducer will not show good technical specifications. In recent years pressure distribution sensors have been developed using conductive paint as well as capacitive and piezoelectric transducers. Compared to force platforms, pressure distribution sensors allow a much more detailed analysis of the mechanical interaction of the human body with the ground. Pressure devices generally demonstrate reduced accuracy and lower frequency responses as compared to traditional force platforms. Strain gage, inductive, and piezoelectric technologies are also applied for the construction of accelerometers. They are important for the measurements of shock and vibrations at various parts of the body. Skin motion is a major problem for acceleration measurements in biomechanics, and care should be taken to minimize these artifacts. Applications: The use and the limitations of ground reaction force measurements will be demonstrated for locomotor and other athletic activities. In-shoe pressure distribution techniques have proven valuable in product testing of athletic footwear. Differences between shoes can easily be detected and the aging of material with use can be tested. The substantial influence of skin motion on acceleration measurements will be demonstrated, and methods will be suggested to reduce these skin artifacts. Running and tennis will be chosen as examples to demonstrate the use of acceleration measurements

BIOMECHANICAL EVALUATION OF RUNNING AND SOCCER SHOES: METHODOLOGY AND TESTING PROCEDURES

Running shoes are the footwear, that has been explored the most by scientists in the field of biomechanics. Following the running shoe research peak between 1980 and 1990 other products became the focus of interest. In particular, many shoe studies were performed in the field of basketball and other indoor sports. Only recently, soccer boots have received a lot of attention and were explored by various research groups. Other than in running shoes, soccer boots have additional tasks to perform. These shoes are used for kicking, they should provide sufficient traction for rapid cutting manoeuvres and assist the players in rapid acceleration and stopping movements. Especially, the often conflicting demands of injury prevention and high performance properties remain to be solved. Test methods for athletic footwear as well as research results will be presented here. This will demonstrate how important biomechanics has become in providing the necessary knowledge for the design of functional footwear