Charge and Magnetic Flux Correlations in Chern-Simons Theory with Fermions

Charge and magnetic flux bearing operators are introduced in Chern-Simons theory both in its pure form and when it is coupled to fermions. The magnetic flux creation operator turns out to be the Wilson line. The euclidean correlation functions of these operators are shown to be local and are evaluated exactly in the pure case and through an expansion in the inverse fermion mass whenever these are present. Physical states only occur in the presence of fermions and consist of composite charge-magnetic flux carrying states which are in general anyonic. The large distance behavior of the correlation functions indicates the condensation of charge and magnetic flux.Comment: Latex, 17 page

Threshold detection in an on-off binary communications channel with atmospheric scintillation

The optimum detection threshold in an on-off binary optical communications system operating in the presence of atmospheric turbulence was investigated assuming a poisson detection process and log normal scintillation. The dependence of the probability of bit error on log amplitude variance and received signal strength was analyzed and semi-emperical relationships to predict the optimum detection threshold derived. On the basis of this analysis a piecewise linear model for an adaptive threshold detection system is presented. Bit error probabilities for non-optimum threshold detection system were also investigated

BIOMECHANICS OF TAKEOFF TECHNIQUES IN MODIFIED JUMPING ACTIVITIES

Introduction It is an accepted fact that a fast approach run is of significant importance for success in certain jumping events, such as the long jump and triple jump. This claim is supported, at least subjectively, by the observation that several of the world's greatest jumpers have also been world-class sprinters. Theoretically, maximum distance in jumping requires that the jumper attain not only a high H y at the takeoff point but also some V y as well, to ensure a sufficient flight time. Some horizontal jumpers intuitively place the takeoff leg well ahead of the center of gravity (C ofG) of the body and lean backwards in an effort to achieve a greater V y and thus a higher jump. Practical experience, however, dictates that "reaching" with the takeoff leg does not improve overall performance, perhaps because it causes a loss ofH y at the point of takeoff. It has been suggested that technique which emphasizes height in the jump might only increase the final V y at the expense of a greater reduction of H y (Tellez, 1980). That is, there might possibly be a trade off between vertical and horizontal velocities at takeoff

WORK-ENERGY ANALYSIS OF ICE SKATERS UNDER PROGRESSIVE CONDITIONS OF FATIGUE

NI

Van der Waals and resonance interactions between accelerated atoms in vacuum and the Unruh effect

We discuss different physical effects related to the uniform acceleration of atoms in vacuum, in the framework of quantum electrodynamics. We first investigate the van der Waals/Casimir-Polder dispersion and resonance interactions between two uniformly accelerated atoms in vacuum. We show that the atomic acceleration significantly affects the van der Waals force, yielding a different scaling of the interaction with the interatomic distance and an explicit time dependence of the interaction energy. We argue how these results could allow for an indirect detection of the Unruh effect through dispersion interactions between atoms. We then consider the resonance interaction between two accelerated atoms, prepared in a correlated Bell-type state, and interacting with the electromagnetic field in the vacuum state, separating vacuum fluctuations and radiation reaction contributions, both in the free-space and in the presence of a perfectly reflecting plate. We show that nonthermal effects of acceleration manifest in the resonance interaction, yielding a change of the distance dependence of the resonance interaction energy. This suggests that the equivalence between temperature and acceleration does not apply to all radiative properties of accelerated atoms. To further explore this aspect, we evaluate the resonance interaction between two atoms in non inertial motion in the coaccelerated (Rindler) frame and show that in this case the assumption of an Unruh temperature for the field is not required for a complete equivalence of locally inertial and coaccelerated points of views.Comment: 8 pages, Proceedings of the Eighth International Workshop DICE 2016 Spacetime - Matter - Quantum Mechanic

WORK-ENERGY ANALYSIS OF TRIATHLETES RUNNING UNDER BIKE/RUN AND RUN ONLY CONDITIONS

INTRODUCTION The biomechanics of running have been well documented over the past several decades and considerable material on both the kinematics and kinetics of competitive and recreational running is available. This extends to the effiCiency or economy of running but unfortunately, it appears, not to the efficiency of the running rriathlete. The triathlon is a rapidly developing competitive sport requiring proficiency in swimming, cycling, and running. As such, triathletes are required to run long distances following extended periods of other forms of exercise. Specifically, a long distance run normally follows a cycling race. At present, it appears that little research has focused on the effects of this prior activity on the mechanics of the run portion of a triathlon. No evidence has been found of attempts to look at the work-energy characteristics of the run portion of a triathlon. The purpose of the study, therefore, was to determine if a triathlete's running mechanics are altered at various intervals during a 10 km run or if they are altered by having just completed a 40 km bike ride. SpeCifically, an attempt was made to focus on both the kinematics of triathlete running as well as the work-energy characteristics of the running motion at various points during a run and in runs made under different conditions

Analysis of Selected Mechanics of the Backward C - Cut Ice Skating Stride

The purpose of the study was to evaluate the contributlon of structural and performance variables to the skating velocity of ice hockey players performing the backward C-cut ice skating technique. Ten skilled male ice hockey players volunteered to participate in this study. Each was filmed during a maximum effort backward skating task. An overhead view of each trial was recorded at 100 Hz using a Locam 16 mm camera. Data were collected from film using an Altek AC 30 digitizer and micro-computer system. Fourteen structural and kinematic dependent variables were measured. In addition three kinematic characteristics of the forward skating patterns of the same subject sample were also recorded. A Pearson product-moment correlation analysis was used to look at the relationships between skating velocity and each of the other dependent variables. Also, correlations between selected backward and forward characteristics were computed. The mean backward skating velocity of the sample was 6.56 m/s which resulted from a mean cycle length of 4.53 m and a mean cycle rate of 1.5 cycles per second. Only minor differences were found between right and left stride lengths and times so it was concluded that the movement pattern is symmetrical from side to side. Correlation analysis indicated that velocity is significantly related to both cycle width (r = .80) and cycle length (r = .84). Cycle time was also significantly related to veloclty (r = -.70). Not surprisingly cycle length and rate were significantly related in a negative direction (r - -.91). In an attempt to determine whether backward skating ability is a unique skill, backward velocity was correlated with forward velocity. The result revealed that those who skate fastest backward also tend to skate fastest forward (r ..81). The velocity of the backward trials was about 80 % of that of forward skating trials. Based on the results of the study, it was concluded that there is a strong relationship between selected descriptive aspects of the backward skating movement and the criteria skating veloclty. In addition, it was concluded that a strong relationship exists between backward and forward ice skating ability

MODIFICATIONS OF FORCE DISTRIBUTION IN NOVICE ROCK CLIMBING TECHNIQUE

Introduction: Learning to rock climb is largely a matter of learning how to use the feet, to keep in balance over them, and to relay as little as possible on the arms and hands. Climbing should be performed primarily with the legs and feet because the lager postural muscles involved have greater endurance than those in the upper body. In addition, balance is a very important element of climbing technique. The objective is to keep the weight over the base of support. Often, climbers move out of balance and place demands on the hands and arms, as some climbs require, but ideally the climber returns to a balanced position as quickly as possible to rest the arms and hands

Phosphate solubilizing bacteria from the rhizosphere of Theobroma grandiflorum (Willd. ex Spreng.) Schum. and Bactris gasipaes H.B.K.: potential for plant growth promotion.

We have isolated bacteria from the rhizosphere of two perennial crop plants (Bactris gasipaes and Theobroma grandiflorum) growing on the SHIFT experimental site near Manaus