Quantisation of the Electromagnetic Field and Spontaneous Photon Emission

We develop the method of canonical quantisation for the case of the free electromagnetic field. We choose the Coulomb gauge, which has a simpler physical interpretation. We introduce the creation and annihilation operators in this framework. The formalism is applied to the problem of spontaneous emission of radiation from an excited atomic state at first order in the perturbation expansion. This allows us to obtain a concrete physical result, namely the computation of an excited state decay rate, and, at the same time, have a first look at abstract concepts, such as gauge invariance and renormalisation.

From a Bubbling Swirl of Signs

De-sign is an activity that is a result of semiotic and design processes combined to give a desired outcome. It is an outcome brought about by the conscious mind. But a De-sign outcome can be either tangible or intangible. Intangible results can lead to either an objective or a purely objective product. In other words, it can be a physical result or an imaginative state of mind. This paper explores the latter process of De-sign and how it relates to fictional subject matters and film. A commentary on language, beginning with the alphabet and moving onto the advent of written language, is included. The paper progresses from the world of written language, to an exploration of the mutable, purely objective world of fiction, to the more objective, rigid world of film, where elements left to the imagination, when reading, become fixed with little left for the purely objective activities of the mind. It will be shown that De-sign is an approach common to all purely objective thinking, whether it has an intangible or a tangible final product.

Penggunaan Analisis Regresi Linear Berganda untuk Mendapatkan Model Prediksi Respon Asam Lemak Bebas dan Dobi Hasil Rebusan Tandan Buah Segar Sawit

Target of this research are : ( 1) Knowing physical result of steaming of Fresh Fruit Bunch; ( 2) Knowing the chemical of result of steaming of Fresh Fruit Bunch; ( 3) Finding model of prediction respon result of sterilization of Fresh Fruit Bunch ( 4 ) Determining time depth of steaming most precise to condition of raw material ( FFB ) to be sterilization. This research done at PT.Bio Nusantara Teknologi Bengkulu, by using horizontal type sterilizer. Research method the used experiment which is direct to be done at factory. Multiple regression analysis to analyse data obtained, to the investigation of influence of free variable to variable of respon representing indicator efficacy of sterilization operation. Result of research indicate that treatment of variation : heavy classification of bunches, fruit maturity and time depth steaming to have an effect on to respon result of sterilization perceived. Model of Prediction of met steaming respon as follows : Y1(Evaporation %) = 5,18 - 0,042 X1- 0,012 X2+0,082 X3 ; Y2 ( Fruit lose, g)=1629,96+8,14X1 - 3,22 X2 - 10,22 X3 ; Y3(Throughput apart mesokarp, g / men ) = - 0,748 - 0,297 X1 + 0,111 X2 + 0,336 X3 ; Y4 (percent heavy of mesokarp = 60,12 - 0,044 X1 + 0,018 X2 - 0,103 X3 ; Y5 ( Amount of kernel break = - 1,515 - 0,06 X1+ 0,035 X2 + 0,115 X3 ; Y6 ( FFA )= - 0,655 + 0,011 X1 + 0,029 X2 + 0,032 X3 and Y7 ( DOBI) = 5,205 - 0,001 X1 + 0,01 X2 - 0,024 X3. Time depth steaming correct to braise small FFB, unrippe = 95 minute with score assess 7; Small FFB, mature = 95 minute with score assess 6; Small FFB over mature = 90 minute with score assess 6. Time depth steaming correct for big FFB, unrippe = 100 minute with wight assess 6; Big FFB mature = 80 minute with score assess 5 and for big FFB, over mature = 95 minute with score assess 6.

CASIMIR PISTONS FOR MASSIVE SCALAR FIELDS

The Casimir force on two-dimensional pistons for massive scalar fields with both Dirichlet and hybrid boundary conditions is computed. The physical result is obtained by making use of generalized ζ-function regularization technique. The influence of the mass and the position of the piston in the force is studied graphically. The Casimir force for massive scalar field is compared to that for massless scalar field.

GAUGE DEPENDENCE OF FERMION MASS RENORMALIZATION PRESCRIPTIONS

We discuss the gauge dependence of fermion mass definition under the on-shell and pole mass renormalization prescriptions. By the two-loop-level calculation of the cross section of the physical process [Formula: see text], we prove for the first time that the on-shell fermion mass renormalization prescription makes physical result gauge-dependent. On the other hand, such gauge dependence does not appear in the result of the pole mass renormalization prescription. Our calculation also implies that the difference of physical results between the two mass renormalization prescriptions cannot be neglected at two-loop level.

Sexual health and cancer

Introduction 630 Assessment and communication about sexual health 632 Cancer is associated with a number of sexual problems. Some of these are a direct physical result of the cancer or its treatment (see Table 52.1): • Disfigurement or loss of sexual organs through surgery (e.g. breasts, testes, gynaecological surgery)....

The remote past of the Flemish legal term balfart: The county of Flanders as the cradle of the notions bolwerk, boulevard and belfort

Based on the Germanic warda, a military term originated in the Low Frankish area, namely *balward. Within the county of Flanders, *balward developed into an institution (better known as balfart) which was responsible for bolwerc, being the construction and maintenance of fortifications. In course of time, bolwerc became a common name for the physical result of these efforts. A terminological confusion between both terms led to the materialization of *balward as *bolward, which gave rise to the French boulevard. Early differentiation of the Low Frankish *balward resulted in two variants for 'belfort', namely *balferd and balfred. The first variant independently developed in Flanders and was introduced in the French-speaking area. The second variant, conserved in Medieval Latin, spread from the Low Frankish region to the English-speaking area. The remarkable German spelling bergfried can be explained by south-east migration of the hybrid form *balgfred.

Black holes: Quantum trapping and singularity resolution

We describe recent progress on the problem of gravitational collapse in quantum gravity. The model we study is the gravity-scalar field theory in spherical symmetry, which is the original setting for Hawking's semiclassical work on black-hole radiation. We present an approach to full quantization of this model in a Hamiltonian framework, with a view to understanding the late time behaviour of collapsing matter. We give operator realizations of curvature and null expansion variables. The first of these operators has a bounded spectrum indicating curvature singularity avoidance; the second provides a "quantum trapping" criterion for detecting whether a quantum state describes a black hole. It leads to the physical result that the boundary of a quantum black hole is subject to quantum fluctuations. We describe an approach to quantum dynamics, whereby an initial state can be evolved, and tracked to the point of quantum trapping and beyond.PACS Nos.: 04.60.–m, 04.60.Ds, 04.70.Dy

BOSON SEA VERSUS DIRAC SEA: GENERAL FORMULATION OF THE BOSON SEA THROUGH SUPERSYMMETRY

We consider the long standing problem in field theories of bosons that the boson vacuum does not consist of a "sea," unlike the fermion vacuum. We show with the help of supersymmetry considerations that the boson vacuum indeed does also consist of a sea in which the negative energy states are all "filled," analogous to the Dirac sea of the fermion vacuum, and that a hole produced by the annihilation of one negative energy boson is an antiparticle. Here, we must admit that it is only possible if we allow — as occurs in the usual formalism anyway — that the "Hilbert space" for the single particle bosons is not positive definite. This might be formally coped with by introducing the notion of a double harmonic oscillator, which is obtained by extending the condition imposed on the wave function. This double harmonic oscillator includes not only positive energy states but also negative energy states. We utilize this method to construct a general formalism for a boson sea analogous to the Dirac sea, irrespective of the existence of supersymmetry. The physical result is consistent with that of the ordinary second quantization formalism. We finally suggest applications of our method to the string theories.

Laminar channel flow driven by accelerating walls

The two-dimensional flow of a viscous incompressible fluid in a channel with accelerating walls is analysed by use of Hiemenz's similarity solution. Steady flows and their instabilities are calculated, and unsteady flows are computed by solving the initial-value problem for the governing partial-differential system. Thereby, these exact solutions of the Navier–Stokes equations are found to exhibit turning points, pitchfork bifurcations, Hopf bifurcations and Takens–Bogdanov bifurcations along the route to chaos. The substantial physical result is that the chaos previously found for flows with symmetrically accelerating walls is easily destroyed by a little asymmetry.