On the derivative formulas of the rotation minimizing frame in Lorentz–Minkowski 3-space

Firat Yerli̇kaya ◽  
İsmai̇l Aydemi̇r

The main intention of this paper is to analyze integrability for the derivative formulas of the rotation minimizing frame in the Lorentz–Minkowski 3-space. As far as we know, no one has yet given a method to study their integrability in the Lorentz–Minkowski 3-space. So, we introduce the coordinate system in order to provide a tool for studying the integrability. As an application, the position vectors of some special curves having an important place in mathematical and physical research are obtained in the natural representation form. Finally, we support our work with examples.

1975 ◽  
Vol 26 ◽  
pp. 87-92
P. L. Bender

AbstractFive important geodynamical quantities which are closely linked are: 1) motions of points on the Earth’s surface; 2)polar motion; 3) changes in UT1-UTC; 4) nutation; and 5) motion of the geocenter. For each of these we expect to achieve measurements in the near future which have an accuracy of 1 to 3 cm or 0.3 to 1 milliarcsec.From a metrological point of view, one can say simply: “Measure each quantity against whichever coordinate system you can make the most accurate measurements with respect to”. I believe that this statement should serve as a guiding principle for the recommendations of the colloquium. However, it also is important that the coordinate systems help to provide a clear separation between the different phenomena of interest, and correspond closely to the conceptual definitions in terms of which geophysicists think about the phenomena.In any discussion of angular motion in space, both a “body-fixed” system and a “space-fixed” system are used. Some relevant types of coordinate systems, reference directions, or reference points which have been considered are: 1) celestial systems based on optical star catalogs, distant galaxies, radio source catalogs, or the Moon and inner planets; 2) the Earth’s axis of rotation, which defines a line through the Earth as well as a celestial reference direction; 3) the geocenter; and 4) “quasi-Earth-fixed” coordinate systems.When a geophysicists discusses UT1 and polar motion, he usually is thinking of the angular motion of the main part of the mantle with respect to an inertial frame and to the direction of the spin axis. Since the velocities of relative motion in most of the mantle are expectd to be extremely small, even if “substantial” deep convection is occurring, the conceptual “quasi-Earth-fixed” reference frame seems well defined. Methods for realizing a close approximation to this frame fortunately exist. Hopefully, this colloquium will recommend procedures for establishing and maintaining such a system for use in geodynamics. Motion of points on the Earth’s surface and of the geocenter can be measured against such a system with the full accuracy of the new techniques.The situation with respect to celestial reference frames is different. The various measurement techniques give changes in the orientation of the Earth, relative to different systems, so that we would like to know the relative motions of the systems in order to compare the results. However, there does not appear to be a need for defining any new system. Subjective figures of merit for the various system dependon both the accuracy with which measurements can be made against them and the degree to which they can be related to inertial systems.The main coordinate system requirement related to the 5 geodynamic quantities discussed in this talk is thus for the establishment and maintenance of a “quasi-Earth-fixed” coordinate system which closely approximates the motion of the main part of the mantle. Changes in the orientation of this system with respect to the various celestial systems can be determined by both the new and the conventional techniques, provided that some knowledge of changes in the local vertical is available. Changes in the axis of rotation and in the geocenter with respect to this system also can be obtained, as well as measurements of nutation.

1975 ◽  
Vol 26 ◽  
pp. 21-26

An ideal definition of a reference coordinate system should meet the following general requirements:1. It should be as conceptually simple as possible, so its philosophy is well understood by the users.2. It should imply as few physical assumptions as possible. Wherever they are necessary, such assumptions should be of a very general character and, in particular, they should not be dependent upon astronomical and geophysical detailed theories.3. It should suggest a materialization that is dynamically stable and is accessible to observations with the required accuracy.

2001 ◽  
pp. 29-36
N. Nedzelska

The paradox of the existence of the species Homo sapiens is that we do not even know: Who are we? Why are we? Where did you go from? Why? At all times - from antiquity to our time - the philosophers touched on this topic. It takes an important place in all religions of the world. These eternal questions include gender issues. In the religious systems of the religions of the Abrahamic tradition there is no single answer to the question of which sex was the first person. Recently, British scientists have even tried to prove that Eve is 84 thousand years older Adam

2019 ◽  
Vol 1 (1) ◽  
pp. 40-50
Jose Luis Turabian

Psychology and sociology share a common object of study, human behaviour, but from different perspectives. Sociologists have focused on macro variables, such as social structure, education, gender, age, race, etc., while psychology has focused on micro variables such as individual personality and behaviours, beliefs, empathy, listening, etc. Despite the importance of interpersonal relationship skills, they depend on the community or social context in which communication takes place, and by themselves may have little relevance in the consultation. The purely psychological analysis of the doctor-patient relationship often leads to an idyllic vision, with the patient-centred consultation as the greatest exponent, which rarely occurs in real life. The purely sociological or community / social analysis of the doctor-patient relationship leads to a negative view of the consultation, which is always shown as problematic. But, the psychological system in the doctor-patient relationship cannot be neglected, and its study is of importance, at least as an intermediate mechanism that is created through socio-community relations. Although the same social causes are behind the doctor-patient relationship, when acting on psychological factors in the consultation, they act as an optical prism scattering socio-community relations that affect the doctor and the patient, giving rise to a beam of different colors of doctor-patient relationship. In doctor-patient relationship there is a modality of psychotherapy, where attitudes, thoughts and behaviour of the patient, can be change, as well as it can be extended on the way of understanding and therefore changing, his social context. Because of the distance between socio-community relations and the form of doctor-patient relations is growing in complex societies, under these conditions, the sociological factor gives the important place to the psychological factor. Given these difficulties of the doctor-patient relationship one may ask how general medical practice can persist with the usual model of doctor-patient relationship. Pain and the desire to relieve them are the basic reasons for the patient and the doctor, and they do not disappear due to the contradictions of the doctor-patient relationship. In this way, the confrontation between sociological and psychological vision is replaced by an alliance of both currents, and each of them takes on meaning only in the general vision.

1986 ◽  
Vol 113 (2) ◽  
pp. 226-232 ◽  
Laszlo Hegedüs ◽  
Dagmar Veiergang ◽  
Steen Karstrup ◽  
Jens Mølholm Hansen

Abstract. Thyroid function and thyroid gland volume, ultrasonically determined, were investigated in 27 hyperthyroid patients with solitary autonomous thyroid nodules before and during one year after 131I-treatment. Total thyroid volume decreased gradually from 40.9 ± 3.5 ml (mean ± sem) before treatment to 23.9 ± 1.8 ml (P < 0.001) at 3 months after 131I-treatment. No further change was observed. All but two patients received only one dose of 131I, and in spite of a significant decrease also of the non-adenoma side of the gland, none became hypothyroid. We conclude that 131I-therapy has an important place in the treatment of solitary autonomous thyroid nodules since all our patients became euthyroid within 3 months, only 2 of 27 patients needed more than one dose of 131I, no cases of hypothyroidism occurred, and thyroid volume was substantially decreased.

2019 ◽  
Vol 15 (2) ◽  
pp. 154-165 ◽  
Elena N. Mokshina ◽  
Mihail I. Svyatkin

Introduction. The article deals with the main traditional outbuildings of the Mordvinians, reported on their functional purpose in economic activity. The forms and types of outbuildings, as well as the main building materials used by Mordvinians are described in details. Their significance in the religious and ceremonial life of the ethnic group is shown. Materials and Methods. The research is based on traditional methods of ethnographic science, such as field observation, survey and interviews, and a comprehensive approach. Among the methods of historical science comparative-historical, historical-genetic, problem-chronological, structural-system were used. Among the general scientific methods of research logical, descriptive, narrative, generalization, classification and systematization were involved. To achieve the results of the study, the materials collected by the authors in the course of field surveys conducted in the Mordovian villages were mainly used. Results and Discussion. Traditional outbuildings were of great importance in the economic activity of the Mordovian ethnic group. According to their functional purpose, they can be divided into the following groups: for livestock and poultry (stable, chicken coop, stable, kalda), sanitary and hygienic (bath), warehouse buildings for storage of food, utensils, firewood, animal feed (barn, cellar, woodshed, hayloft), for processing of grain (sheep, riga, mill). Depending on the welfare and financial capacity of the family, the number of outbuildings was different. As a rule, the wealthier families had more outbuildings than the less wealthier ones. The main building material for the construction of these buildings was wood. Conclusion. Thus, the traditional outbuildings of the Mordvinians occupied an important place in its economic activities. At the same time, each of them had its own purpose and performed certain functions. Some buildings, such as a bath and a barn, had not only economic purpose, but also were the venue for a number of prayers and ceremonies. It is now ordinarily they have banya (bath-house), outdoor courtyard with standing in different places sheds, barn and cellar.

2020 ◽  
Vol 65 (2) ◽  
pp. 189-202
Yvonne Goga

"Theatre as an Image of Proust’s Aesthetic. In In Search of Lost Time, theatre holds an important place, especially in the first three volumes. Being part of the frequent activities of society, it gives many occasions to the narrator to express his thoughts about theatre shows. Our aim will be to demonstrate that those thoughts are one of the ways used by Proust to bring out his complex theory about novelistic creation – a theory which shows to what extent art’s aim is to access the essence of things through sensitive experience. Keywords: art, theatre show, sensitive experience, essence, artistic conception."

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