scholarly journals From Black Holes to Neutrino Stars

Author(s):  
Roumen Tsekov

Due to limitation of the binding energy of a self-gravitating matter, the radius of a body is at least twice larger than the Schwarzschild radius. The total energy is adsorbed at the body surface, giving rise of a size-dependent surface tension. Since the Hawking temperature appears to be the critical one, the black holes possess zero surface tension. Microscopic neutrino stars are also introduced.

2021 ◽  
Author(s):  
Andrey Chernov

Abstract In this study, a new concept is introduced into physics - gravitational cells. These cells are densely compressed elementary particles: a proton and an electron. The body of a black hole consists of a huge number of such cells. On this theoretical basis, using the Schwarzschild radius formula and the adapted Coulomb formula, a formula for the gravitational constant was obtained and its value in the gravitational field of black holes was calculated, 𝑮𝟎=𝟔,𝟕𝟗𝟐𝟕∙𝟏𝟎−𝟏𝟏. Also, scientific substantiation of the value of the usual gravitational constant 𝑮 was obtained. In this study, a new physical constant was determined - the mass of the gravitational cell of a black hole 𝒎𝟎=𝟏,𝟓𝟏𝟏𝟓𝟗𝟑∙ 𝟏𝟎−𝟐𝟕 kg. Based on the results of the study, conclusions were drawn regarding the gravitational mass of the proton and the electron.


Author(s):  
Xueliang Wen ◽  
Peiqing Liu ◽  
Qiulin Qu ◽  
Tianxiang Hu

Abstract The present paper proposes an approximate solution for the varying speed impact of 3D bodies on the water surface, with the assumptions that the fluid is considered to be incompressible, inviscid, weightless and with negligible surface tension effects and the flow ro be irrotational. The approximate solution provides a linear relationship between Cp and a dimensionless variable K, and the equation of body acceleration. These equations can be used to rapidly predict the pressure distribution on the body surface and the motions of the body. The predictions of the approximate solution match the CFD results very well for the varying speed impacts, including the normal and oblique impacts of a cone on the water surface and the normal impact of a pyramid on the water surface. The present approximate solution can be suitable for the 2D, axisymmetric and fully 3D impacts of bodies on the water surface with varying speed.


1990 ◽  
Vol 29 (04) ◽  
pp. 282-288 ◽  
Author(s):  
A. van Oosterom

AbstractThis paper introduces some levels at which the computer has been incorporated in the research into the basis of electrocardiography. The emphasis lies on the modeling of the heart as an electrical current generator and of the properties of the body as a volume conductor, both playing a major role in the shaping of the electrocardiographic waveforms recorded at the body surface. It is claimed that the Forward-Problem of electrocardiography is no longer a problem. Several source models of cardiac electrical activity are considered, one of which can be directly interpreted in terms of the underlying electrophysiology (the depolarization sequence of the ventricles). The importance of using tailored rather than textbook geometry in inverse procedures is stressed.


Author(s):  
Shirazu I. ◽  
Theophilus. A. Sackey ◽  
Elvis K. Tiburu ◽  
Mensah Y. B. ◽  
Forson A.

The relationship between body height and body weight has been described by using various terms. Notable among them is the body mass index, body surface area, body shape index and body surface index. In clinical setting the first descriptive parameter is the BMI scale, which provides information about whether an individual body weight is proportionate to the body height. Since the development of BMI, two other body parameters have been developed in an attempt to determine the relationship between body height and weight. These are the body surface area (BSA) and body surface index (BSI). Generally, these body parameters are described as clinical health indicators that described how healthy an individual body response to the other internal organs. The aim of the study is to discuss the use of BSI as a better clinical health indicator for preclinical assessment of body-organ/tissue relationship. Hence organ health condition as against other body composition. In addition the study is `also to determine the best body parameter the best predict other parameters for clinical application. The model parameters are presented as; modeled height and weight; modelled BSI and BSA, BSI and BMI and modeled BSA and BMI. The models are presented as clinical application software for comfortable working process and designed as GUI and CAD for use in clinical application.


Author(s):  
A. S. Sharipov ◽  
◽  
B. I. Loukhovitski ◽  

The size-dependence of different physical properties of atomic clusters (by the example of binding energy, collision diameter, and static isotropic polarizability) is discussed.


2021 ◽  
Vol 116 ◽  
pp. 103915
Author(s):  
Chihiro Iiyama ◽  
Fuyu Yoneda ◽  
Masaya Tsutsumi ◽  
Shigeyuki Tsutsui ◽  
Osamu Nakamura

Dermatology ◽  
2021 ◽  
pp. 1-9
Author(s):  
María Luisa Peralta-Pedrero ◽  
Denisse Herrera-Bringas ◽  
Karla Samantha Torres-González ◽  
Martha Alejandra Morales-Sánchez ◽  
Fermín Jurado Santa-Cruz ◽  
...  

<b><i>Background:</i></b> Vitiligo has an unpredictable course and a variable response to treatment. Furthermore, the improvement of some vitiligo lesions cannot be considered a guarantee of a similar response to the other lesions. Instruments for patient-reported outcome measures (PROM) can be an alternative to measure complex constructions such as clinical evolution. <b><i>Objective:</i></b> The aim of this study was to validate a PROM that allows to measure the clinical evolution of patients with nonsegmental vitiligo in a simple but standardized way that serves to gather information for a better understanding of the disease. <b><i>Methods:</i></b> The instrument was created through expert consensus and patient participation. For the validation study, a prospective cohort design was performed. The body surface area affected was measured with the Vitiligo Extension Score (VES), the extension, the stage, and the spread by the evaluation of the Vitiligo European Task Force assessment (VETFa). Reliability was determined with test-retest, construct validity through hypothesis testing, discriminative capacity with extreme groups, and response capacity by comparing initial and final measurements. <b><i>Results:</i></b> Eighteen semi-structured interviews and 7 cognitive interviews were conducted, and 4 dermatologists were consulted. The instrument Clinical Evolution-Vitiligo (CV-6) was answered by 119 patients with a minimum of primary schooling. A wide range was observed in the affected body surface; incident and prevalent cases were included. The average time to answer the CV-6 was 3.08 ± 0.58 min. In the test-retest (<i>n</i> = 53), an intraclass correlation coefficient was obtained: 0.896 (95% CI 0.82–0.94; <i>p</i> &#x3c; 0.001). In extreme groups, the mean score was 2 (2–3) and 5 (4–6); <i>p</i> &#x3c; 0.001. The initial CV-6 score was different from the final one and the change was verified with VES and VETFa (<i>p</i> &#x3c; 0.05, <i>n</i> = 92). <b><i>Conclusions:</i></b> The CV-6 instrument allows patient collaboration, it is simple and brief, and it makes it easier for the doctor to focus attention on injuries that present changes at the time of medical consultation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mayukh Nath ◽  
Shovan Maity ◽  
Shitij Avlani ◽  
Scott Weigand ◽  
Shreyas Sen

AbstractRadiative communication using electromagnetic fields is the backbone of today’s wirelessly connected world, which implies that the physical signals are available for malicious interceptors to snoop within a 5–10 m distance, also increasing interference and reducing channel capacity. Recently, Electro-quasistatic Human Body Communication (EQS-HBC) was demonstrated which utilizes the human body’s conductive properties to communicate without radiating the signals outside the body. Previous experiments showed that an attack with an antenna was unsuccessful at a distance more than 1 cm from the body surface and 15 cm from an EQS-HBC device. However, since this is a new communication modality, it calls for an investigation of new attack modalities—that can potentially exploit the physics utilized in EQS-HBC to break the system. In this study, we present a novel attack method for EQS-HBC devices, using the body of the attacker itself as a coupling surface and capacitive inter-body coupling between the user and the attacker. We develop theoretical understanding backed by experimental results for inter-body coupling, as a function of distance between the subjects. We utilize this newly developed understanding to design EQS-HBC transmitters that minimizes the attack distance through inter-body coupling, as well as the interference among multiple EQS-HBC users due to inter-body coupling. This understanding will allow us to develop more secure and robust EQS-HBC based body area networks in the future.


Sign in / Sign up

Export Citation Format

Share Document