Includes bibliographical references (p. 74-79).

Abstract- This paper will investigate the use of a three-to-one Matrix converter to synchronize the electrical energy and condition the output of the wind generator. A Matrix converter is a direct ACAC solution, removing the need for large smoothing capacitors in a typical rectifier/inverter solution. This paper will briefly review the Matrix converter operational theory. A simulation and the practical results of a three-to-one phase matrix converter for varying input frequencies are also presented. The conclusion shows that the proposal is a viable solution for small power wind harvesting.

Stretching exercises are commonly used as an integral part of a pre-exercise warm-up training sessions despite even early laboratory studies having demonstrated that some degree of mechanical weakness takes place following the stretching of muscle tissue. This study compared the effects of four treatments (n = 12 each) [10 minutes of quiet sitting, without stretching (NS); two minutes warm up on an arm ergometer at 25 watts resistance (WU); 10 second-hold static stretching (each) of the shoulder, chest and arm muscle groups (ST10); and two sets of 20 second-hold static stretching (each) of the shoulder, chest and upper-arm muscle groups (ST20)] on a 1-RM bench press in 48 subjects who were matched for their pre-test 1-RM bench press values. The mean 1-RM bench press values following ST10 (45.0 ± 9.9 kg) and WU (48.9 ± 10.5 kg) treatments were significantly (p ? 0.05) higher at the post-test than at the pre-test 1-RM (43.9 ± 10.1 kg and 43.9 ± 10. kg, respectively). The mean 1-RM values following the ST20 treatment was significantly lower (41.9 ± 10.0 kg) than at pre-test (43.9 ± 10.1 kg). However, multiple comparisons and Analysis of Variance (ANOVA) statistical procedures demonstrated that there was no significant difference from pre- to post-test between the four groups. These findings suggest that the use of stretching activities prior to events requiring maximal force production may not be obligatory or may even be contraindicated since the effects of stretching are then to decrease the amount of force that can be produced via the natural elastic components of the muscle and tendons and via the stretch reflex.

Abstract Stretching exercises are commonly used as an integral part of a pre-exercise warm-up training sessions despite even early laboratory studies having demonstrated that some degree of mechanical weakness takes place following the stretching of muscle tissue. This study compared the effects of four treatments (n = 12 each) [10 minutes of quiet sitting, without stretching (NS); two minutes warm up on an arm ergometer at 25 watts resistance (WU); 10 second-hold static stretching (each) of the shoulder, chest and arm muscle groups (ST10); and two sets of 20 second-hold static stretching (each) of the shoulder, chest and upper-arm muscle groups (ST20)] on a 1-RM bench press in 48 subjects who were matched for their pre-test 1-RM bench press values. The mean 1-RM bench press values following ST10 (45.0 ± 9.9 kg) and WU (48.9 ± 10.5 kg) treatments were significantly (p ? 0.05) higher at the post-test than at the pre-test 1-RM (43.9 ± 10.1 kg and 43.9 ± 10. kg, respectively). The mean 1-RM values following the ST20 treatment was significantly lower (41.9 ± 10.0 kg) than at pre-test (43.9 ± 10.1 kg). However, multiple comparisons and Analysis of Variance (ANOVA) statistical procedures demonstrated that there was no significant difference from pre- to post-test between the four groups. These findings suggest that the use of stretching activities prior to events requiring maximal force production may not be obligatory or may even be contraindicated since the effects of stretching are then to decrease the amount of force that can be produced via the natural elastic components of the muscle and tendons and via the stretch reflex.

Certain numerical methods have been well developed for solving one-dimensional two-phase flow (e.g. gas and liquid) problems in the literatures during the last two decades. Based on the existing methods, the present work compares the computational efficiency, accuracy, and robustness of various numerical schemes by predicting the numerical solutions of fluid properties for a specific case to find the proper numerical method. One of the numerical schemes introduced in this work is a practical, semi-implicit upwind method used for fluid flow simulations in different flow patterns,stratified flow and slug flow. This method implements the iterative and non-iterative schemes using a two-fluid model that consists of sets of non-hyperbolic equations. A numerical error term is applied in the pressure equation to maintain the volume balance of the two-phase flow model. If the temperature varies, the discretised energy equations use similar error terms as in the pressure equation. In some cases, the small values of the numerical errors are negligible and do not influence the numerical results. These errors are, however, important factors to consider when maintaining the stability and robustness of the above numerical schemes for strong non-linear cases. The computational efficiency ofthe non-iterative scheme, where the inner iterations are deactivated, is better than the iterative scheme. Different grid arrangements are compared with respect to computational accuracy and efficiency. A staggered structured grid implements the same semi-implicit upwind method as in the non-iterative scheme; the non-staggered grid arrangement uses an existing flux-splitting scheme (Evje and Flåtten, 2003) as a reference. All the above schemes produce numerical solutions with a single precision that normally satisfy the requirements of computational accuracy of industrial two-phase pipe flows. However, if one pursues a higher-order accuracy scheme, e.g. a Roe-averaged algorithm, the governing equations should be strictly a hyperbolic system of partial differential equations, which is achieved by introducing the nonviscous force terms in the two-fluid model (LeVeque, 2002).By properly incorporating the non-conservative terms in the formulation of the numerical fluxes, the capability of the Roe-averaged algorithm is demonstrated by capturing shock waves. Results from the present research include the following. A one-dimensional scheme that solves a system of discretised equations with the staggered semi-implicit upwind method is presented and validated for its computational efficiencyand robustness. This scheme can be widely used in the industry with sufficient accuracy. The other first-order semi-implicit numerical schemes producestable numerical results, especially in the dynamic cases of two-phase flow, except when the gas phase nearly disappears or appears in pipes. The Roe-averaged algorithm is recommended due to the high-resolution numerical results obtained, but at the costs of computational time and effort.

An experiment was performed to measure the impulse of the A8-3 Estes model rocket engine. The measurements were obtained by mounting an engine vertically onto a frame and measuring the changing weight of the assembly during the firing period for six trials. Thrust was calculated by the difference in measured weight from the rest weight while accounting for the mass loss rate. The impulse of each of the six thrust curves was averaged to find the final impulse measurement: 2.36 (+/-) .16 N-s. Estimates of the average thrust and exhaust velocity were also calculated from the impulse measurement.

Light bulbs play an indispensable role in our lives as they provide unhindered ability to see the world even during the night. Efficiency of light bulbs is becoming increasingly important, and through this experiment, light bulb efficiencies are analyzed from measurements of relative light intensity and power input of various bulbs. Furthermore, this report is aimed to increase awareness of the efficiency advantage in fluorescent bulbs and to encourage their usage in the interest of conserving energy.

The two interconnected rubber balloons system is a demonstration widely used to show the effect of surface tension; however, the nature of the rubber skin, sizes of the balloons limit the ability of this demonstration. In this research, I measured the circumference and pressure of balloons for the calculation of surface tension. It was found that the demonstration can be done between circumferences of 30 cm to 50 cm for the party balloons to show the effect of surface tension as explained by the Laplace-Young equation.

One Flew Over the Cuckoo’s Nest (1962) written by Ken Kesey tells the story at a ward where the patients who reside at the ward are exposed of oppression and humiliation by Nurse Ratched. One Flew Over the Cuckoo’s Nest: A Play in Two Acts (1963) written by Dale Wasserman is a theatrical play which is based on Kesey’s novel. The purpose of this essay is to argue that Nurse Ratched’s character is pictured as more evil in the novel than the play. In this essay, Ratched’s personality and outer looks was discussed as well as her methods she uses to humiliate and control the inmates. It was argued that Wasserman may have excluded information about Ratched’s character, so the actors have a chance to develop a personal view of Ratched. It was also argued that Ratched may have appeared as unnaturally evil if Wasserman had included all her evil traits, and thus picture her as a larger than life character.

No description available.