Cold Welding in Hold Down Points of Space Mechanisms Due to Fretting When Omitting Grease

Cold welding refers to an effect related to space (vacuum). The heavy vibrations during a launch subject interfaces (hold down points) to oscillating motions which may lead to formation of a kind of “friction weld”. If so, these mechanisms may get stuck, and deployment will be hindered. This may endanger the functionality of the mission (instruments) or even the whole spacecraft (if solar panels do not open). Several studies have been done to characterize material combinations (including coatings) for their ability to cold welding in space. Meanwhile, also during launch grease free contacts are demanded. If grease hat to be omitted, the risk of cold welding under fretting was found to increase (when testing in high vacuum). To rate this risk under launch conditions, the test method was recently extended for testing under launch conditions. The new tests procedure consists of fretting applied in the sequence in air, low vacuum and high vacuum. The paper shall present first results gained with this new method of testing in launch conditions and compare them to previous studies done in vacuum. Following the need of space industry on mechanisms for launch and in-orbit life, a first set of combinations of materials and coatings were selected for this new test sequence where fretting is now applied in a sequence of air, low vacuum and high vacuum. Under this sequence, the measured levels of adhesion and it’s evolvement was found to differ strongly from tests done formerly. The paper outlines these first results and compares them to existing data.

Effect of conservation of spatial volume on electromagnetism

This essay presents an alternate mechanism for electromagnetism and provides arguments supporting new concepts of this phenomenon. Electricity and magnetism are defined and influenced by the electric permittivity ε o and magnetic permeability μ o physical constants of the vacuum. This essay's concepts are predicated on the notion that the free-space vacuum appears to be composed of an energy field with characteristics of an elastic medium termed the “spatial energy field” or SEF. It is proposed that the geometric volume of the SEF requires conservation, and this is achieved via stretching or compression of space exhibiting wavelike qualities. The SEF, representing spacetime, has specific properties related to the emergence of an electrical field force via the Poynting vector. Magnetic field force appears to emanate from the SEF based on the Lorentz force. Space (SEF) appears to mediate energy fields, such as electrical and magnetic fields, and provides a framework for the transmission of electromagnetic waves in addition to momentum-gravitational waves. Conservation of spatial volume influences these phenomena.

MECHANISM OF ROTATION OF GEOSPHERES OF THE PLANET EARTH

In recent decades, a fundamentally new direction of scientific work has appeared in the field of natural sciences, associated with the study of the effect on matter of such physical factors as radiation, electromagnetic radiation, ultrasound, plasma, high pressure, space vacuum, gravity, etc., where the general criterion of extremeness exposure can be the emergence of intermediate highly active states of particles of matter, which ultimately leads to a qualitative change in the micro- and macro characteristics of the processed object, the emergence of new properties. One of the types of complex extreme exposure is the effect of a high-voltage electric discharge, which combines the simultaneous action on a substance of strong mechanical compression, powerful ultrasound, hard X-ray, UV and IR radiation. The electromagnetic fields generated in the course of the discharge also have a strong effect on both the discharge itself and the ionic processes occurring in the surrounding liquid. Under their influence, various physical changes and chemical reactions occur in the processed material.

METHANOGENIC ARCHAEA IN THE SPACE ENVIRONMENT

Next phase of experiment TEST is aimed to evaluate microbial viability after a prolonged external exposure on the International space station (ISS). Methanogenic archaea isolated from various habitats have been tested in ground facilities for the ability to survive exposure to such open space factors as UV and vacuum. Methanosarcina mazei S-6T (VKM B-1636T) was found to be the most viable and, therefore, suitable for the experiment. Our investigations showed that the Methanosarcina mazei population maintained viability in the course of 24-month exposure. On this evidence we conclude that genome of this metanogenic archaea possesses mechanisms against the space vacuum, UV and thermal differences that, probably, underlie the ability of the strain to form peculiar cyst-like dormant cells.

The Newman-Penrose map and the classical double copy

Gauge-gravity duality is arguably our best hope for understanding quantum gravity. Considerable progress has been made in relating scattering amplitudes in certain gravity theories to those in gauge theories — a correspondence dubbed the double copy. Recently, double copies have also been realized in a classical setting, as maps between exact solutions of gauge theories and gravity. We present here a novel map between a certain class of real, exact solutions of Einstein’s equations and self-dual solutions of the flat-space vacuum Maxwell equations. This map, which we call the Newman-Penrose map, is well-defined even for non-vacuum, non-stationary spacetimes, providing a systematic framework for exploring gravity solutions in the context of the double copy that have not been previously studied in this setting. To illustrate this, we present here the Newman- Penrose map for the Schwarzschild and Kerr black holes, and Kinnersley’s photon rocket.

Rapid Optical Spin Initialization of a Quantum Dot in the Voigt Geometry Coupled to a Two-Dimensional Semiconductor

We study the interaction of a quantum dot in the Voigt configuration with a laser pulse and particularly analyze the potential for rapid spin initialization by putting the quantum dot near a molybdenum disulfide (MoS 2 ) monolayer. The MoS 2 monolayer influences the spontaneous decay rates of the quantum dot, leading to anisotropically enhanced decay rates, for the quantum dot’s electric dipole moments parallel and perpendicular to the layer. By solving the relevant density matrix equations, we find that high spin initialization fidelity is obtained at short times. The fidelity is significantly higher than when the quantum dot is in free-space vacuum. We examine two different cases of the interaction of the quantum dot with the applied optical field. First, we use a continuous wave laser field and determine for various quantum dot—MoS 2 layer distances the field strength that leads to acceptable fidelity levels. The effect of the quality of the MoS 2 material on the fidelity of spin initialization is also examined. We also study the interaction of the quantum dot with a laser pulse and apply numerical optimal control to obtain the time-dependent field strength, which leads to maximum final fidelity for short time intervals. The latter approach gives beneficial results in comparison to the continuous wave field excitation.

An Innovative Ultrasonic Apparatus and Technology for Diagnosis of Freeze-Drying Process

The freeze-drying process removes water from a product through freezing, sublimation and desorption procedures. However, the extreme conditions of the freeze-drying environment, such as the limited space, vacuum and freezing temperatures of as much as −50 °C, may block the ability to use certain diagnostic sensors. In this paper, an ultrasonic transducer (UT) is integrated onto the bottom of a specially designed frozen bottle for the purpose of observing the freeze-drying process of water at varying amounts. The temperatures and visual observations made with a camera are then compared with the corresponding ultrasonic signatures. Among all of the diagnostic tools and technologies available, only ultrasonic and visual records are able to analyze the entire progression of the freeze-drying process of water. Compared with typical experiment settings, the indication of drying point for water by the amplitude variations of ultrasonic L3 echo could reduce the process period and energy consumption. This study demonstrates how an innovative frozen bottle, an integrated ultrasonic sensor and diagnostic methods used to measure and optimize the freeze-drying process of water can save energy.