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Dark world and the standard modelZhao, Gang 02 June 2009 (has links)
The most popular way to achieve accelerated expansion of the universe is by introducing a scalar field in which motion of state varies with time. The accelerated expanded universe was first observed by Type Ia supernovae and future confirmed by the latest of CMB (Cosmic Microwave Background). The reason for the accelerated universe is the existence of dark energy. In this dissertation, we discuss the relationship between dark matter, dark energy, reheating and the standard model, and we find that it is possible for us to unify dark energy, dark matter and a reheating field into one scalar field. There is a very important stage called inflationary, and we find that the residue of the inflationary field, which is also described by a scalar field, can form bubbles in our universe due to the gravity force. We discuss that these bubbles are stable since they are trapped in their potential wells, and the bubbles can be a candidate for dark matter. We also discuss the scalar singlet filed, with the simplest interaction with the Higgs field, and we find that a static, classical droplet can be formed. The physics picture of the droplet is natural, and it is almost the same as the formation of an oil droplet in water. We show that the droplet is absolutely stable. Due to the very weak interaction with the Standard Model particles, the droplet becomes a very promising candidate for dark matter.
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Two phase mixing comparison, oil contamination comparison and manufacturing accuracy effect on calibration of slotted orifice meterSparks, Sara A. 15 November 2004 (has links)
In previous studies the slotted orifice plate has demonstrated superior performance characteristics to those of the standard orifice plate. In this study, these comparisons are investigated further. The response characteristics of the slotted orifice plate to the standard orifice plate and V-Cone for two-phase flows of water and air at various qualities, flow rates, and pressures are shown visually. The effect of oil as it flows through a slotted orifice plate and standard orifice plate are visually documented. The effect of manufacturing accuracy on the slotted orifice plates is investigated as to the effect on the coefficient of discharge, percent change in pressure, and Reynolds number. The slotted orifice plate mixes two-phase flow better than the standard orifice plate and V-Cone. There is a manufacturing effect on the slotted orifice plates; the larger the area of the slots, the larger the discharge coefficient.
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Non-Standard English Features in the Song Lyrics of Best Selling Music in SwedenMangseth, Henrik January 2010 (has links)
No description available.
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Fermionic fields with mass dimension one as supersymmetric extension of the O'Raifeartaigh modelWunderle, Kai Erik 25 November 2010
The objective of this thesis is to derive a supersymmetric Lagrangian for fermionic fields with mass dimension one and to discuss their coupling to the O'Raifeartaigh model which is the simplest model permitting supersymmetry breaking. In addition it will be shown that eigenspinors of the charge conjugation operator (ELKO) exhibit a different transformation behaviour under discrete symmetries than previously assumed.<p>
The calculations confirm that ELKO spinors are not eigenspinors of the parity operator and satisfy (<i>CPT</i>)<sup>2</sup> = - 1 which identifies them as representation of a nonstandard Wigner class. However, it is found that ELKO spinors transform symmetrically under parity instead of the previously assumed asymmetry. Furthermore, it is demonstrated that ELKO spinors transform asymmetrically under time reversal which is opposite to the previously reported symmetric behaviour. These changes affect the (anti)commutation relations that are satisfied by the operators acting on ELKO spinors. Therefore, ELKO spinors satisfy the same (anti)commutation relations as Dirac spinors, even though they belong to two different representations of the Lorentz group.<p>
Afterwards, a supersymmetric model for fermionic fields with mass dimension one based on a general superfield with one spinor index is formulated. It includes the systematic derivation of all associated chiral and anti-chiral superfields up to third order in covariant derivatives. Starting from these fundamental superfields a supersymmetric on-shell Lagrangian that contains a kinetic term for the fermionic fields with mass dimension one is constructed. This on-shell Lagrangian is subsequently used to derive the on-shell supercurrent and to successfully formulate a consistent second quantisation for the component fields. In addition, the Hamiltonian in position space that corresponds to the supersymmetric Lagrangian is calculated. As the Lagrangian is by construction supersymmetric and the second quantisation of the component fields is consistent with their general supertranslations, the Hamiltonian is positive definite. This is confirmed by the results for the Hamiltonian in momentum space and the derivation of the creation and annihilation operators in momentum space. Based on these results, fermionic fields with mass dimension one represent an intriguing candidate for supersymmetric dark matter.<p>
As an application the coupling of the fermionic fields with mass dimension one to the O'Raifeartaigh model is discussed. It turns out that the coupled model has two distinct solutions. The first solution representing a local minimum of the superpotential spontaneously breaks supersymmetry in perfect analogy to the O'Raifeartaigh model. The second solution is more intriguing as it corresponds to a global minimum of the superpotential. In this case the coupling to the fermionic sector restores supersymmetry. This is, however, achieved at the cost of breaking Lorentz invariance. Finally, the mass matrices for the multiplets of the coupled model are presented. It turns out that it contains two bosonic triplets and one fermionic doublet which are mass multiplets. In addition it contains a massless fermionic doublet as well as one fermionic triplet which is not a mass multiplet but rather an interaction multiplet that contains component fields of different mass dimension.<p>
These results show that the presented model for fermionic fields with mass dimension one is a viable candidate for supersymmetric dark matter that could be accessible to experiments in the near future.
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Fermionic fields with mass dimension one as supersymmetric extension of the O'Raifeartaigh modelWunderle, Kai Erik 25 November 2010 (has links)
The objective of this thesis is to derive a supersymmetric Lagrangian for fermionic fields with mass dimension one and to discuss their coupling to the O'Raifeartaigh model which is the simplest model permitting supersymmetry breaking. In addition it will be shown that eigenspinors of the charge conjugation operator (ELKO) exhibit a different transformation behaviour under discrete symmetries than previously assumed.<p>
The calculations confirm that ELKO spinors are not eigenspinors of the parity operator and satisfy (<i>CPT</i>)<sup>2</sup> = - 1 which identifies them as representation of a nonstandard Wigner class. However, it is found that ELKO spinors transform symmetrically under parity instead of the previously assumed asymmetry. Furthermore, it is demonstrated that ELKO spinors transform asymmetrically under time reversal which is opposite to the previously reported symmetric behaviour. These changes affect the (anti)commutation relations that are satisfied by the operators acting on ELKO spinors. Therefore, ELKO spinors satisfy the same (anti)commutation relations as Dirac spinors, even though they belong to two different representations of the Lorentz group.<p>
Afterwards, a supersymmetric model for fermionic fields with mass dimension one based on a general superfield with one spinor index is formulated. It includes the systematic derivation of all associated chiral and anti-chiral superfields up to third order in covariant derivatives. Starting from these fundamental superfields a supersymmetric on-shell Lagrangian that contains a kinetic term for the fermionic fields with mass dimension one is constructed. This on-shell Lagrangian is subsequently used to derive the on-shell supercurrent and to successfully formulate a consistent second quantisation for the component fields. In addition, the Hamiltonian in position space that corresponds to the supersymmetric Lagrangian is calculated. As the Lagrangian is by construction supersymmetric and the second quantisation of the component fields is consistent with their general supertranslations, the Hamiltonian is positive definite. This is confirmed by the results for the Hamiltonian in momentum space and the derivation of the creation and annihilation operators in momentum space. Based on these results, fermionic fields with mass dimension one represent an intriguing candidate for supersymmetric dark matter.<p>
As an application the coupling of the fermionic fields with mass dimension one to the O'Raifeartaigh model is discussed. It turns out that the coupled model has two distinct solutions. The first solution representing a local minimum of the superpotential spontaneously breaks supersymmetry in perfect analogy to the O'Raifeartaigh model. The second solution is more intriguing as it corresponds to a global minimum of the superpotential. In this case the coupling to the fermionic sector restores supersymmetry. This is, however, achieved at the cost of breaking Lorentz invariance. Finally, the mass matrices for the multiplets of the coupled model are presented. It turns out that it contains two bosonic triplets and one fermionic doublet which are mass multiplets. In addition it contains a massless fermionic doublet as well as one fermionic triplet which is not a mass multiplet but rather an interaction multiplet that contains component fields of different mass dimension.<p>
These results show that the presented model for fermionic fields with mass dimension one is a viable candidate for supersymmetric dark matter that could be accessible to experiments in the near future.
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Redovisningskonsulten och Reko : är Reko ett steg mot att utveckla yrket som auktoriserad redovisningskonsult till att bli en profession?Brundin Franksson, Jessica, Eisersiö, Anne January 2011 (has links)
Huvudsyftet är att belysa redovisnings-konsulter och Reko samt att återge en representativ överblick över hur redovisningskonsulter själva upplever att Reko påverkar deras yrkesrolls utveckling till att bli en profession.I denna studie har kvantitativ metod använts. Data har samlats in genom en granskning av teori och tidigare forskning inom ämnesområdet samt en enkätundersökning som har gått ut till branschorganisationen Fars redovisningskonsulter. Vi har redovisat och analyserat data med hjälp av en regressionsanalys, hypoteser och tabeller.
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An ecophysiological framework for the morphological evolution of bluegill sunfishPapadopoulos, Anthony 15 May 2009 (has links)
Body shape affects the capacity and efficiency of swimming in fishes, and places
constraints on foraging and reproductive performance. Hence, fitness components, such
as aerobic swimming capacity and efficiency, can be determined from analysis of
swimming energetics using active respirometry. In particular, body shape adaptations,
such as streamlining, aim at reducing hydrodynamic drag (resistance), thereby increasing
swimming efficiency in the presence of water flow, which is a principal contributor to
resistance for fish inhabiting rivers. For two populations of bluegill sunfish, one from the
Brazos River and the other from Moelman’s Slough (a Brazos River oxbow lake), the
metabolic transport rate (MTR) was determined to evaluate differences in swimming
efficiency. The standard cost of swimming (SCOS) was also determined to evaluate
differences in swimming capacity, which represents the overall capacity of the skeletal
muscles to generate mechanical power to overcome hydrodynamic resistance. The MTR
and the SCOS describe holistic swimming performance, where the MTR specifies the
hydrodynamic response due to swimming, and the SCOS specifies the physiologic
response due to swimming. The differences in swimming performance are mainly
attributed to factors affecting hydrodynamic resistance and could be predicted by
morphology; because body shape, like water flow, is also a principal contributor to
resistance. Multivariate body shape, from generalized Procrustes analysis, was used to
assess the influence of multiple shape traits on swimming costs. This measure of shape
related to swimming performance using partial least-squares analysis showed the two bluegill populations to be significantly different. The results were as follows: the
shallow-bodied condition in bluegills was highly correlated with efficient swimming and
low swimming capacities; whereas, deep-bodied bluegills were highly correlated with
inefficient swimming and high swimming capacities. This is an empirical case of
divergent natural selection. For convergence, however, the position of the caudal
peduncle is consistent with optimal swimming speed (Um), which depends on standard
metabolic rate (SMR), or metabolic maintenance. Bluegills with erect caudal peduncles
have a high range of swimming speeds without suffering much cost of swimming ability
compared to bluegills with prone caudal peduncles. The adaptive physiological response
to high Um is due to a low SCOS because swimming efficiency is low and metabolic
maintenance is high. In other words, bluegills that are inefficient swimmers and require a
high energy intake cannot survive unless they gain the ability to increase their foraging
capacity by thrust or metabolic power reduction. This is perhaps one of the most
remarkable adaptive physiological responses due to the joint effects of shape and SMR.
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Dark world and the standard modelZhao, Gang 02 June 2009 (has links)
The most popular way to achieve accelerated expansion of the universe is by introducing a scalar field in which motion of state varies with time. The accelerated expanded universe was first observed by Type Ia supernovae and future confirmed by the latest of CMB (Cosmic Microwave Background). The reason for the accelerated universe is the existence of dark energy. In this dissertation, we discuss the relationship between dark matter, dark energy, reheating and the standard model, and we find that it is possible for us to unify dark energy, dark matter and a reheating field into one scalar field. There is a very important stage called inflationary, and we find that the residue of the inflationary field, which is also described by a scalar field, can form bubbles in our universe due to the gravity force. We discuss that these bubbles are stable since they are trapped in their potential wells, and the bubbles can be a candidate for dark matter. We also discuss the scalar singlet filed, with the simplest interaction with the Higgs field, and we find that a static, classical droplet can be formed. The physics picture of the droplet is natural, and it is almost the same as the formation of an oil droplet in water. We show that the droplet is absolutely stable. Due to the very weak interaction with the Standard Model particles, the droplet becomes a very promising candidate for dark matter.
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A Study of Antenna Factor of Broadband Antennas for Electromagnetic Compatibility by simulation and measurementTien, Kai-Wen 22 July 2005 (has links)
The researches of this thesis are divided into two parts. One is to investigate the applicability of ANSI C63.5 in high frequencies of 1 GHz to 6 GHz. In general, the Standard Site Method (SSM) of C63.5 is usually used to calculate the antenna factors for the calibration of broadband antennas. Through the theoretical calculations, the numerical simulations and measurements, we found that the discrepancies between the calibrated results of horizontal and vertical polarization related to the un-dipole-like pattern in higher frequencies. Furthermore, we analyzed the relations of the antenna factors, the heights of receive antennas and the radiation patterns. We also found that the predicted calibration results can be close to the practical ones by including the effects of radiation patterns. The other research is to study the issue about the ground plane size of a test site. The ground plane size of a qualified test site must be larger than the minimum size defined by C63.7. For this reason, we provide a method which combines the tilted antennas measurement with a trapezoid shape ground. By using this method in the smaller ground size, we can obtain the measured results close to those obtained in the larger ground size. This method can effectively reduce the required ground size and then decrease the installation cost of a test site. Meanwhile, this method can be applied for both of the horizontal and vertical polarizations.
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A Circuit Generator for Logic Reduction of Boolean Functions and Its Application to the Design of Advanced Encryption StandardLin, Chi-Cheng 25 July 2005 (has links)
The constant matrix multiplication is one of the key operations in many applications including digital signal processing, communication, and coding. In general, constant matrix multiplication can be expressed as bit-level Boolean functions. Then, common subexpression elimination (CSE) can be used to reduce the area cost of realizing these bit-level functions by finding the shared common factors among these bit-level equations. The proposed circuit generator performs logic reduction on the input Boolean functions and produces the simplified Verilog HDL codes as output. Then the simplified code is fed into Synopsys Design Compiler for further logic minimization and technology mapping to generate gate-level netlists. In this thesis, we present ten different CSE algorithms for logic reduction of the bit-level Boolean functions. The comparisons include both the architecture-level technology-independent results and the Synopsys synthesized technology-dependent results. According to the experiments, we observe that our CSE can effectively reduce the area cost. We also apply the CSE to the design of the Advanced Encryption Standard (AES) in cryptography.
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