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In this first paper we examine the formal mathematical description of the postulates for the General Theory of Relativity (GTR), Like it was formulated in the sixties years. These abstract formulation -in contrast to the common one allows to obtain new results, like the existence of singularities. In a next paper we will discuss the physlcal meaning of such postulates.

Organic solar cells (OSCs) are one of the best alternatives in the photovoltaic area. These devices convert directly sunlight into electrical current with reasonable efficiencies. The most important component of an OSC is the photoconductive active layer which can be made of small organic molecules. In this theoretical study, a quantum chemical approach was applied to calculate the properties such as the energy of Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO), LUMO-HOMO energy gap, and the theoretical 1H NMR chemical shifts (the latter only for one molecule) for four organic molecules that exist in the literature. The geometry optimization of the four small molecules and the corresponding calculations were performed using Gaussian 09 software by means of the Density Functional Theory (DFT) at the B3LYP/6-31G(d) theoretical level. All the reported experimental values given in the papers were compared with the obtained theoretical values via a linear regression analysis. Our computational study showed good agreement with the experimental data as the regression analysis showed a coefficient of determination greater than 0.99.

There is a solid growth of quantum theory in that there is quantum physics, quantum chemistry, quantum biology, and a robust technology based on quantum behaviors and effects - to name but the most solid examples of the development and enhancement of quantum science. Quantum science is by and large the most robust theory, ever. However, to date there is a gap between quantum physics and the social sciences, for very little has been said about their interplay. This paper discusses the importance of a relationship between quantum science and the social sciences, and the entailment of such a relation. It offers a brief state-of-the-art, and discusses the very significance of quantum social science.

The correct interpretation of the layout of fetal monitoring is a challenge for current clinical; recently a diagnostic methodology based on the theories of probability and entropy, which managed to assess in an objective and reproducible way the layout of differentiating normal fetal monitoring and evolution of disease between these states was developed. The aim of this paper is to apply this methodology to assess fetal monitoring tracing and confirm their clinical applicability and reproducibility. For this 25 fetal monitoring in 20 minutes divided into two groups were evaluated: 10 normal and 15 with loss of fetal well-being, according to the conventional interpretation of the monitoring, and general clinical evaluation. Heart rates presented in discrete time intervals from the paths they took, and the likelihood and the S/k ratio of entropy was evaluated. The S/k relations of entropy for normal differentiated evaluated by monitors disease. The clinical applicability of physical and mathematical diagnostic assessment of fetal monitoring tracing was confirmed.

Nanotechnology involves the characterization, manufacture and / or manipulation of structures, devices or materials, which have at least one dimension, sizes between 1 and 100 nm. At this scale, the resulting material exhibits better properties significantly different from those presented by the same material on a macroscopic scale, contributing in this way to the improvement of our quality of life, essentially in the diagnosis and medical therapy, energy production, molecular computation and structural material. That is why, increasingly, groups belonging to academic sectors (universities and colleges), and the community in general, are interested in learning about Nanoscience and Nanotechnology, which day by day are gaining national and international spaces . One of the ways to contribute to the dissemination and training in these areas is from the universities, through the creation of student research seeds in the areas of Nanoscience and Nanotechnology, linked to research groups working on these areas. This paper presents the experience of the Nanostructured Magnetic Materials Research Seedling, assigned to the Science and Characterization of Materials research group of the Physics program of the Universidad del Atlántico, in its diffusion and training activity in Nanoscience and Nanotechnology. The structure, the main topics of the research seed, its mission and its objectives are analyzed. It is emphases on the training, socialization and research activities of the research seed, as well as on the dissemination and research results of itself.

Sustainable development considers as a central axis the set of external physical, chemical, and biological components with which the living beings interact and which, with respect to the human being, comprises the set of natural, social and cultural factors existing in a place and in a determined moment that influence life and will affect future generations. Advances in Nanosciences and Nanotechnologies in general, and the increasing use of nanomaterials in various consumer products in particular, have allowed for specific applications for the care and preservation of the environment, raising worldwide interest in large sectors of the society on its social and environmental implications, which belongs to the field of the relationship between Nanosciences, Nanotechnologies and Bioethics. The analysis of this relationship and how the Dissemination and Training of Nanosciences and Nanotechnologies can contribute to sustainable development is the main objective of the present paper.

Use almost inseparable from the technological resources in social, professional and emotional dimensions, suggest a new process of sociocultural and cognitive resignification. Such developments gain notoriety with the advent of new technologies of information and communication (NTIC), bringing new horizons for educational practices. ICTs in the future will be based on emerging technologies that will integrate and articulate knowledge from different areas of knowledge in an interdisciplinary manner in educational proposals. These disruptive technologies tend to provide significant advances in areas such as: technology information, holography, nanotechnology, biotechnology, cognitive science, robotics and artificial intelligence. Among this range of possibilities, including technologies capable of express representations of reality or imagination, sometimes difficult to abstraction. In this context, holography and virtual reality meet methodological assumptions that act in an active way and that motivate, with high power of illustration and interactivity. This paper presents the findings on the use of holography and virtual reality for the teaching of concepts in nanoscience and nanotechnology (N&N) in secondary education. Methodologically, this work was developed with use of these technologies for the teaching of N&N in scientific events in the period between 2015 and 2017. The results show that the interactive elements of these technologies can enhance and corroborate to the meaningful learning of concepts related to N&N, and which are difficult for the abstraction of the students.

Proca's electrodynamics describes a theory of massive photons which is not gauge invariant. In this paper we show that the gauge invariance is recovered if a scalar field is properly incorporated into the theory. We followed the Dirac's technique to perform a detailed analysis of the constraint structure of the theory. Appropriate gauge conditions were derived to eliminate the first class constraints and obtain the Dirac's brackets of the independent dynamical variables. Alternatively, the generalized symplectic formalism method is used to study the gauge invariance Proca's electrodynamics theory. After fixing the gauge, the generalized brackets are calculated and the equivalence with the Dirac's brackets is shown.

This paper presents the process followed in the implementation of a vibrating sample magnetometer (VSM), constructed with materials commonly found in an electromagnetism laboratory. It describes the design, construction, calibration and use in the characterization of some magnetic materials. A VSM measures the magnetic moment of a sample when it is vibrated perpendicular to a uniform magnetic field; Magnetization and magnetic susceptibility can be determined from these readings. This instrument stands out for its simplicity, versatility and low cost, but it is very sensitive and capable of eliminating or minimizing many sources of error that are found in other methods of measurement, allowing to obtain very accurate and reliable results. Its operation is based on the law of magnetic induction of Lenz-Faraday that consists in measuring the induced voltage in coils of detection produced by the variation of the magnetic flux that crosses them. The calibration of the VSM was performed by means of a standard sample (Magnetite) and verified by means of a test sample (Nickel).

In many countries, it has been tried to define this concept and there are many proposals globally, but why is it important to have a precise definition of what NANOMATERIAL means? From the point of view of materials science definition can be very clear, a natural material or manufactured containing particles in unbound state or as an aggregate or agglomerate in combination with one or more external dimensions in the range comprised sizes from 1 to 100 nm. However, the need for a definition that can be used to establish legislation that protects living beings from the possible risks of sucking, inhaling or otherwise absorb these materials is increasingly urgent. Furthermore, this definition must be sufficiently broad and accurate to ensure the implementation of this concept. This paper presents a summary of the possible risks of using nanomaterials in numerous applications and growing unsecured it appears that the tests normally used in standard chemical compounds, are also suitable for nanomaterials. The efforts made so far worldwide to standardize test methods and establish best practices manuals are also shown. Some definitions adopted in Europe, the United States and Australia as a starting point to propose that meets the conditions of accuracy, completeness and accuracy in order to establish the appropriate methodology to ensure the safe use by workers and public in general and also protect the environment.

This paper will expound how to obtain a parametric equation that make possible to model orbital trajectories of objects around large macroscopic bodies, in special black holes, without the use of tensor calculus. The mathematical model allows the characterization of trajectories of pairs of black holes using parameters whose values depend mainly on whole numbers, in a way very similar to how some quantum numbers determine quantum states of the hydrogen atom, enabling a simple taxonomic system for them.

In this paper we review the basics of PET and discuss the fundamental principle of the physics of PET, the detection of photons and the creation of sinograms. The principles of PET image formation as described with the presentation of the basic back-projection technique and the now well established statistical iterative image reconstruction technique. We also discuss the implementation of the positron range correction and the inclusion of the time-of-flight information for the purpose of improve image contrast and signal to noise.

Medical cyclotrons are now commonly used for the production of PET nuclides by the (pn) reaction. These devices are typically capable of delivering 10-15 MeV protons beams at sufficiently high intensity for timely production of β+ decaying nuclides. Non-conventional PET nuclides have emerged recently and offers new opportunities for diagnostic and therapy drug discovery. In this paper, we will review the production capabilities for such nuclides at Washington University Medical School in St. Louis and present their production. Finally, challenges for imaging imposed by the specific of the decay characteristics will be discussed.

In the early twenty-first century we have witnessed the progress of a large emerging scientific and technological system, nanotechnologies, seen by its promoters as the new technological revolution. The essence of this system lies in the manipulation of matter at the atomic and molecular level, which makes these advances esoteric for most of the non-specialized publics. This leads us to ask how to cope with developments that we cannot see or feel, that few understand but are changing our lives? The way society gets involved in their construction is critical to how people will react to these new technologies. In this paper we compare the social construction of nanotechnologies in the United States, Spain and Mexico, to try to understand the path of these advances in each of these countries.

This paper presents the work done by the Iberoamerican Network "José Roberto Leite" on Dissemination and Training in Nanotechnology, NANODYF, belonging to Area 6 “Science and Society” of the Ibero-American Program of Science and Technology for Development, CYTED, in fulfillment of its mission and its general and specific objectives. Also the tasks performed and results achieved by the NANODYF network during the first three years of its operation are summarized. Furthermore a future strategy is shown to improve and enhance aspects of dissemination and training Nanotechnology, which has evolved considerably at the Iberoamerican region, but much remains to be done.

At present there is some evidence showing that the satellite galaxies of the Milky Way might be distributed on a disc structure, known as the disc of satellites. In this paper a study on the possible formation of the disc of satellites of the Milky Way as the result of a collision between two disc galaxies ~10 Gyr ago is shown. The study is carried out by numerical N-Body simulations with 10^6 particles in each galaxy and with a mass ratio of 4 to 1, being the larger galaxy similar to the Milky Way. The results show how tidal forces between the two colliding galaxies produce a spatial distribution of debris, where possible groups of stars lie nearly perpendicular to the plane of the host galaxy, showing similarity in this feature with the disc of satellites of the Milky Way.

Since 2009, the Venezuelan Network of Nanotechnology has developed some activities for the dissemination of this knowledge area, and also promoted joint working initiatives between members interested in advancing in such task. This paper presents an overview of the activities of the network and other groups related to the subject, and also present the network strategies for the future which arises in the context of a broad notion of the meaning of socialization of knowledge as the axis of transformation of society.

This paper presents some thoughts and reflections regarding training in nanotechnology in general, as well as a few examples of initiatives undertaken by some countries. A specific analysis is done about the situation of training in Nanotechnology in some countries in the Iberoamerican Region; in this analysis the successes and current difficulties are presented, as well as initiatives that are conducted and weak points must be considered and improved.

The purpose of this paper is to contribute to the development of materials used in the fabrication of solar cells based on Kesterite type compounds which are being widely investigated because they possess excellent photovoltaic properties and their precursor elements are nontoxic, inexpensive and abundant in nature. We present details of the synthesis and optimization of optical and structural properties of the ternary Cu2SnSe3 (CTSe) compound which is used as a precursor in the synthesis of the Cu2ZnSnSe4. The CTSe compound is formed by a solid state reaction of the metal precursors sequentially evaporated in the presence of elemental selenium, in a two stage process. The optimization of the properties of the CTSe was achieved studying the eéct of synthesis parameters on optical, electrical and structural properties through spectral transmittance, electrical conductivity and X-ray diffraction measurements. The results indicated that these compounds grow with cubic structure and have an optical bandgap of 1.6 eV.

In the nineteenth century, the mechanistic idea of natural phenomena had been consolidated to the point of believing that it was possible to explain all the physical from the mechanical theory. In this paper we show how thermodynamics is influenced by this prejudice, beginning with the fundamental hypothesis that motivated and led Helmholtz to give a mechanical interpretation of the principles of thermodynamics based on the mechanical model of unicycles that finally loses relevance when entering crisis the mechanistic model of the natural world.

Nanoscience is the study of structures of sizes between 1 and 100 nanometers, called nanostructures, which due to their small size behave differently from those at micro and macroscopic scales. These new properties of the materials could result in the manufacture of new products and development of new technologies. There are so many possible applications that it is believed that we are at the beginning of a new technological revolution. In this paper, we try to explain the importance of outreach and educational activities in science in general, and nanoscience in particular. We also briey discuss some activities being undertaken by the Thematic Network \Jose Roberto Leit" Outreach and Education in Nanotechnology, NANODYF (www.nanodyf.org) belonging to the Thematic Area 6 Science and Society, of the Ibero-American Science and Technology Development Program, CYTED.

In this paper we present dc magnetization, ac susceptibility and impedance measurements on amorphous alloy ribbons Co80-xFexB10Si10 with x = 0, 6, 8 and 10 at.%. They indicate that at room temperature these samples have good soft magnetic behavior including the giant magneto-impedance effect. The real part of the ac susceptibility χ’ac reveals an irreversibility field, Hirr, which corresponds to the transverse anisotropy field, Hk, at which the magneto-impedance ratio reaches its maximum value.

In this paper, we present a study of the optical and magnetic properties of AlN/Mn alternating layers, deposited on glass and Si (100) substrates by r.f. magnetron sputtering. The optical characterization was performed using micro-Raman in order to determine A1(TO) E1(TO) and E2(high) vibrational modes of AlN, and a local vibrational mode (MVL) of Mn. The magnetic behavior was analyzed by vibrating sample magnetometry (VSM). From temperature dependent magnetization at zero field cooling (ZFC) and field cooling (FC), and hysteresis loop measurements it was determinated that AlN/Mn multilayers show a ferromagnetic ordering.

The Generalized Method of Transfer Matrix (MMT) appears as an alternative to quantum phenomena research in semiconductor materials and optoelectronic components. In this paper the MMT is applied to the propagation phenomena of a particle through a well or a potential barrier to the quantum case. The relations scattering amplitudes are deduced using the coefficients of the transfer matrix (transmission and reflection). The results are compared with related literature, to determine the accuracy and scope of the MMT, namely which can be applied to study many other problems of wave propagation and electrons, even in layered media as photonic crystals.

In this paper, a design and automation of a DC and AC Hall effect measurement system using a four-wire method is presented. This system consists of a Current Source (Model 6221 DC-AC, Keithley Instruments Inc.) connected to a Nanovoltmeter (Model 2182A, Keithley Instruments Inc.), and an electromagnet (Phylatex) that provides magnetic fields up to 0.8 T. This system has several measurement capabilities including Hall voltage, Hall coefficient, resistance, resistivity, and I-V curves, and can be operated in both DC and AC (up to 10 Hz) current modes (IAC, IDC). The functioning of the Hall effect measurement system was verified using both a standard sample of copper and several resistor circuits that correspond to simulated metallic and semiconductor samples. This measurement system was used to study the magneto-transport properties at room temperature of the soft magnetic amorphous ribbons Co64Fe21B15 and Co71Fe4B15Si10. An analysis of these magneto-transport properties is presented, too.

This paper reviews the tunnelling magnetoresistance (TMR) of magnetic tunneling junctions, particulary of those made of manganites. The origin of this type of tunneling and its dependence on the material, the growing method and the temperature are presented. Besides, some results on the influence of the half-metallicity and of the interfaces on the TMR are discussed.

The glass beads are translucent objects that serve as a pattern to characterize different techniques for measuring phase object. These microspheres are of great importance in assessing metrological techniques, both industrial as medical and scientific level, in the measurement of refractive index. This paper shows the results acquired by using a technique that combines both Digital Holographic Microscopy in transmission and the tomographic reconstruction technique, applying inverse Radon transform. As input were taken the difference phase maps obtained from the registration procedure and holographic reconstruction. The application of this technique allows obtaining 3D maps of the refractive index of glass spheres with diameters of about 200 micrometers.

The satellite galaxies of the Milky Way are very important both for the studies of the formation and evolution of galaxies and for the research on the dark matter problem. In the present review paper some structural properties of the Local Group, as well as of the dwarf spheroidal galaxies that compose this astrophysical system are presented. Special emphasis is paid to the satellite galaxies of the Milky Way and their spatial distribution on the disk of satellites (DoS). Furthermore, the more relevant recent studies related to the formation of the disk of satellites of the Milky Way are mentioned.

Among the aims of this work it is included the description of the domains involved in resent scientific papers related with the treatment and the analysis of the ozone layer and with the solar ultraviolet radiation levels (SUVRL). Furthermore, it’s emphasized the more important developed strategies to face the analysis and monitoring of the ozone layer; also, Finding the trends in the scientific community association in order to do research into ozone layer. Finally, it’s suggested a domain in which Andian countries can construct scientific community for tracking the SUVRL on terrestrial surface. Methodologically, it’s searched the trace of the historical scientific criteria which defined the tools and theoretical advance in the present scientific development. It’s found that after more than thirty five years, since the global problem announcement, it has been organized a very wide and strong international scientific community with which efforts pointed out and gear up governments and international organizations in order to control anthropogenic substances that emitted to the atmosphere hurt the ozone layer. It has been achieved successfully to reduce emissions of “fist generation substances" in more than 95 %, but since the major part of them will stay in the atmosphere for at least 40 or 50 years, it is necessary to continue with the efforts to enhance the current methods of control and measurement and to develop new precise and economical methods.

In this paper we review, in a concise and elucidating way, some of the main properties of the superconductivity in the magnesium diboride, MgB2. One disccuss the transport and some mechanical properties as well as the band structure and relate them to the crystal structure of the material.

This paper reports on the development of a system, along with a description of the development of the associated equipment, for measuring the parameters characterizing the quality of electrical power generated by a grid-connected PV system. The determining of quality parameters such as normal voltage operating range, waveform distortion, frequency, voltage flicker and power factor was achieved through the implementation of Virtual Instruments (VI’s); using the graphic programming soft-ware LabVIEWTM. The system employed the developed VI’s integrated with a data acquisition card and one FieldPoint system from National Instruments. Testing revealed the developed system to be reliable and suitable for studies related to monitoring the electrical power supplied by a grid-connected PV system. Monitoring of the power supplied, by a grid-connected PV system, to a local grid during a time frame of one month, indicated that the developed system complied with all the specifications demanded for such systems by National and International standards.

By the end of the 19th century, Hertz developed an original procedure for the solution of Maxwell equations. He introduced the so-called Hertz potentials (Πe, Πm), which have the very interesting property of making Maxwell equations symmetrical. Application of Hertz’s method to the solution of the oscillating electric dipole is based on a scalar function Q, which is proportional to the electric flux. In this way, the electromagnetic field (E,H) becomes a function of electric flux only. For its pedagogical value, in this paper we describe Hertz’s method, which is neither widely known, nor easily available to most students and researchers. Additionally, we describe in some detail Hertz’s procedure to build the graphs of the electric field (the latter were obtained by Hertz for the first time, and are reproduced in many intermediate textbooks without any explanation), and present the companion graphs for the magnetic field associated with the dipole.

The scanning tunneling microscope (STM) is a superb laboratory instrument for atomic and molecular imaging of surfaces. The STM has also proved to be a powerful tool in the manufacture of nanometer size patterns and structures on solid surfaces. Likewise, the STM permits to conceive a future technology of nanoscale systems and devices capable of reaching the limit of integration involving sigle atom manipulations. This paper illustrates the novel possibilities of STM and shows results and figure that corroborate the potencial use of this microscope in the XXI century electronics industry. In particular, we report experimental results of nanostructures formation, of 100 A order on gold surfaces and gold-graphite bilayers, with a Burleigh Instruments microscope operating in air.

In this paper we make a review of some basic aspects of the microscopic theory of superconductivity for inhomogeneous systems through the Bogoliubov-de Gennes equations which describe the quasiparticles in a superconductor. We show the different scattering processes which occur in a superconductor due to inhomogeneities of the pair potential. These scattering processes appear explicitly in heterostructures and in contacts between metals in the normal state and superconductors. By using a method similar to the Ehrenfest theorern we find the forces which act on the quasiparticles due to the electron-hole and hole-electron scattering which can occur in the above mentioned structures.

In this paper, the possibility of studying both the atomic and electronic structures of a surface as well as the interaction with simple molecules through the Scanning Probe Microscopes (SPMs) is shown. Emphasis on the Scanning Tunneling Microscope (STM) and on the Atomic Force Microscope (AFM) it is made. For each case a description of the instrument, of their operation modes is presented. Sorne interesting applications are also shown.

This paper presents a modern adaptation of Mach 's version of the solution given by Huygens to the compound pendulum problem, a ques tion of historical and didactical interest. An intuitivc solution to the problem of finding the period of osciJation of a ring, is al so proposed.

Ion-atom collisions is a subject investigated from Ruthetford's time. In the last decades, due to the accelerated advance in experimental techniques, coincidence measurements have allowed to study the problem with great detail. Lately, the experimental evidence is often very complex to be analysed theoretically, and in some cases, difficult to match with previous ideas. In the present paper the basic problema and ame recent experiments are summarised.

The membrane paradigm is a method in order to work matter fields near black holes, which allows to construct spatial images changing in time, without lasing the exactness of the general relativity. This paper describes membrane paradigm, and applies it to the electromagnetic field around a Schwarzchild's black holeo.

The present paper discuss some relievant aspects of the application of basic physical concepts in the definition and further development of algorithms for the digital processing of satellite images.

Optical solitons are infrared stable pulses whose shape and spectrum endure over thousands of kilometers. This paper presents a theoretical framework and shows a numerical simulation of solitons propagation in optical fibers.

In this paper we study local symmetries in an arbitrary manifold and we show the properties of the local algebra. We further make some comments on the problem of gauge fixing.

The abstract mathematical formulatlon of the Generel Theory of Relatlvity (GTR), gave in the sixties years, brought forth one of the more Interesting issues in physics: The Penrose-Hawklngs theorems on space-time singularities. In this paper will be discussed the physical meaning of the postulates for the GTR.

In this paper, we present an analysis of the historical circumstances that favored the technical cooperation agreement between the Federal German Republic and the Physics Department of the Universidad Nacional de Colombia. The contributions and the success of such an agreement.

In this paper a modem version of some early physical problems solved by purely geometrical methods are presented. Because It is not necessary a complete and articulated physical theory but some “instintive knowledge”, such an approach can be used in introductory courses as an interesting pedagogical option.

An automatized general physics laboratory course can be used as an opportunity to induce students in the modern techniques 01 acquisition and data processing in real time. In this paper we expose this approach in a set of experiments attached to microcomputers in a general laboratory. Finally the results we have obtained up to now are discussed.

We have found superconducting behavior in thick films fabricated by decantation. In this paper we present the experimental method and results obtained using commercial copper substrates.