Bøger af Abdelkader Benzian

The growth of one semiconductor on another known as Heteroepitaxy process which developed the production of a wide range of what so-called heteroepitaxial devices, such as high-brightness light-emitting diodes, lasers, and high frequency transistors. The development of devices using other materials is based on the choice of the substrate and is represented by the combination epitaxial layer/substrate. This combination using the growth process requires the realizing at the maximum the chemical and crystallographic compatibility in which the crystallographic orientation of the layer is exactly determined by the substrate crystal. The surface structure of the substrate crystal can have an important effect on the properties of the epitaxial crystal. In the other hand, homoepitaxy is another process differs from Heteroepitaxy, if substrate and layer are of the same chemical composition we speak of homoepitaxy such as GaAs/GaAs, and we speak of Heteroepitaxy, if the layer /substrate have different chemical composition such as InP/GaAs. This materials used to product LEDs high quality devises and transistors of high mobility.

The work presented in this book is relevant to the interaction of quantum fields with the classical background manifested by a strong external field. In other words, the background field is adequately described by a classical theory and does not need to be quantized. A significant simplification comes from considering quantized scalar field interacts only with the gravitational field. The Renormalization using zeta function method is the essential requirement of this study for calculated the expectation values of the energy-momentum tensor, in which the quantum effects in a gravitational field induce corrections to the energy-momentum tensor of a matter field, this formulation express the vacuum polarization effects, and the relevant theory is called the Semi-classical theory of gravity.

This book presents the derivation of Dewitt-Wheeler equation in which time-independent equation describes the quantization of the gravitational field in 3-geomtries configuration. This equation may refer as Schrodinger-Einstein equation. This approach of the quantization of the gravity started by Dewitt according to Everett interpretation of quantum mechanics that yields the multiverse idea, and so, the WDW equation introduced a function called lapse function in which each different lapse function according to Dewitt yields a different sequence of 3-geometries that indicates to multiverse. On the other hand, according to Bohm¿s interpretation of quantum potential, the universe is considered as a quantum mechanical system with zero size, and so, the universe may tunnel with a well-defined, nonzero probability which express the creation from non-thing. This idea of the creation from non-thing is supported by Hawking in his articulation in 1988, that, in fact, there was no singularity at the beginning of the universe "it can disappear once quantum effects are taken into account". Penrose agreed.

The molecule of life DNA arises to say that its structure and components are the generators of the diversity of life that serves the continuity. Without changes in DNA sequences, there is no variation, and without variation, there are no changes that can occur in phenotypic variability, no adaptation to environmental changes, and no evolution. This book focuses on the fundamental aspects and machinery of storing, replicating, transmitting, and decoding information by DNA molecules. These processes are the basis for chromosome mapping analysis and genetic recombination manifested essentially in this book by molecular genetic investigations of bacteria and the viruses that invade them. In addition, the characteristics of RNA coronaviruses and their replication are presented.

Março de 1902, William Bateson assinou a sua dissertação "Princípios de Hereditariedade de Mendel", Bateson precisou de ler o artigo de Mendel durante a breve viagem a Londres em 1900, o que iria mudar profundamente o seu mundo. Bateson tinha uma nova missão na vida. Ele compreendeu que o mistério da herança tinha sido resolvido. Logo se tornou um implacável apóstolo das leis sucessórias de Mendel. Alguns anos mais tarde, em 1905, Bateson cunhou o termo genética, e a revolução genética tinha começado. Mendel propôs que os factores que controlam os traços agem como partículas em vez de fluidos e que estas partículas não se misturam, mas são transmitidas intactas de uma geração para a seguinte. Mais tarde, a primeira evidência experimental convincente foi que os genes são feitos de ácido desoxirribonucleico (ADN). Este livro é uma leitura sobre a estrutura e função do ADN e é como uma missão para a ideia de William Bateson.

March 1902, William Bateson signed his dissertation "Mendel¿s Principles of Heredity", Bateson needed to read Mendel¿s paper during the brief journey in London in 1900 which would change profoundly his world. Bateson had a new mission in life. He understood that the mystery of inheritance had been solved. He soon became a relentless apostle of Mendel¿s laws of inheritance. A few years later in 1905, Bateson coined the term genetics, and the genetics revolution had begun. Mendel proposed that the factors that control traits act like particles rather than fluids and that these particles do not blend together but are passed intact from one generation to the next. Later, the first compelling experimental evidence was that genes are made of deoxyribonucleic acid (DNA). This book is a reading on the structure and function of the DNA and is as a mission towards William Bateson idea.

However, what we have not investigated is what really happens at the instant t = 0? this time is usually referred to as the point of time of the Big Bang. Some of the models of the universe's evolution have clearly no singularity, like the k = 1 de Sitter model. Other models have a singularity. In this paper, we will be dedicated to cosmological singularities. We will start out with Einstein's field equations, in order to determine what we need to introduce some technical concepts that lead to the investigation of the existence of the singularities.

Any physical object whose radius R becomes less than or equal to the radius of Schwarzschild will undergo a gravitational collapse and become a black hole where light cannot escape from gravitational fields, this one represents a solution of the Einstien equation, introduced by Schwarzschild, it contains two singularities, one describes the center, and the other describes what is called the horizon of events; black hole and its singularities cannot be considered as Einsteinian¿s pacetimes in any classical sense. Then a new theory of gravitation must be constructed to represent them.

Any physical object whose radius becomes less than or equal to the Schwarzschild radius will undergo a gravitational collapse and become a black hole where light cannot escape from the gravitational fields, this one represents a solution of the Einstein equation, introduced by Schwarzschild, it contains two singularities, one describes the center, and the other describes what is called the event horizon, the black hole and its singularities cannot be considered as Einsteinian space-time in the classical sense. Then, a new theory of gravitation combined between General Relativity and Quantum Theory must be built to represent them.

Maxwell's equations of the electromagnetic field contributed to the development of research on radioactivity, where light is considered as a quantum of energy with the property of a wave - corpuscle. And using the laws of special relativity theory, the research developed to the discovery of new particles which led to the emergence of quantum field theory, which played a key role in the development of particle physics and the discovery of new forces in addition to gravity and electromagnetism. In this book, a brief history of radioactivity, the elementary particles discovered, and the contributions of relativistic quantum mechanics are presented.