Similarities Between Classical Timelike Geodesics in a Naked Reissner-Nordstrom Singularity Background and the Behaviour of Electrons in Quantum Theory

It is generally assumed that naked singularities must be physically excluded, as they could otherwise introduce unpredictable influences in their future null cones. Considering geodesics for a naked Reissner-Nordstrom singularity, it is found that the singularity is effectively clothed by its repulsive nature. Regarding electron as naked singularity, the size of the clothed singularity (electron) turns out to be classical electro-magnetic radius of the electron, to an observer falling freely from infinity, initially at rest. The size shrinks for an observer falling freely from infinity, with a positive initial velocity. For geodetic parameters corresponding to negative energy there are trapped geodesics. The similarity of this picture with that arising in the Quantum Theory is discussed.Comment: 8 pages, 6 figure

Experiments on the Structure of Turbulence in Fully Developed Pipe Flow

This paper describes a series of two-point measurements in fully developed pipe flow. Measurements of the phase shifts between the Fourier components of the axial velocity fluctuations at two points were made with three different orientations of the two points. In all cases the two points were close enough together that the turbulent structure remained essentially frozen while passing between the sensors. The phase velocities, C1(f), and inclinations, α(f) (defined previously by Heidrick et al. (8)), of each frequency component, f, were determined from these measurements. In general, the Fourier components are inclined to the wall - the lower frequencies making smaller angles with the wall than the higher frequencies. The higher frequency disturbances became more nearly perpendicular to the wall in the central region of the pipe. For points very near the wall the disturbances appear to be very obliquely inclined. In the core region, the phase velocity increases with increasing frequency and there is little discernable trend in the phase velocities with respect to position when they are normalized by the local mean velocity. The group velocity of small scale disturbances (large wavenumbers) in the core region appears to be approximately constant and of the order of the local mean velocity. This means that a frozen pattern hypothesis should be valid for these scales. All measurements became more scattered at values of y+ ~\u3c26. This may be due to the intermit- tent nature of the flow near the wall since recent studies in turbulent shear flow suggest that energy transfer from the mean flow to fluctuations near the wall may be due to local instabilities ( bursts ). Thus, the time averaged model is not entirely adequate, and it was necessary to separate out the burst intervals for further study. By suitably processing the two-point velocity signals it was possible to determine when the flow was bursting. The behavior of the velocity and vorticity within measured bursts was determined. This behavior and short-term energy spectra within bursts indicate a weakly periodic behavior. The overall behavior of the flow was shown to be similar to the last stage of the laminar-to-turbulent flow transition

Phase Velocities and Angle of Inclination for Frequency Components in Fully Developed Turbulent Flow Through Pipes

Measurements of phase shift and coherence between the streamwise velocity fluctuations at two sensors placed very close to each other have been made in fully developed turbulent flow in a smooth pipe. For the frequencies where the √coherence is near unity (i.e. the correlation between the frequency components is near unity) the phase shifts have been related to the phase velocities and angle of inclination of a frozen pattern of turbulence. Several other quantities such as intensities, energy spectral densities and mean velocities have also been obtained from the data taken with each sensor and these are in good agreement with previously found values. Probability densities of the streamwise velocity fluctuations were calculated and appear to be positively skewed near the wall and negatively skewed in the central region of the flow. The phase shift measurements indicate that the phase velocities of all but the lowest frequency components are near and somewhat below the local mean velocity in the central region of the pipe and that the disturbance fronts are perpendicular to the wall. Near the wall all the disturbances seem to be inclined - the lower frequencies making smaller angles with the wall than the higher frequencies. The angles of inclination of all disturbances increase with distance from the wall. The phase velocity appears higher than the local mean velocity in this region

A narrative review of heavy metals in cosmetics; health risks

Cosmetics products since the dawn of civilization are considered a part of routine body care. The last few decades these products have had increasing and applied to the human body for beautification. Xenobiotics and heavy metals including chromium, copper, iron, mercury, cadmium, arsenic and nickel, classified as a light metal, are determinate in various types of cosmetics such as color cosmetics, face and body care products, hair cosmetics, herbal cosmetics. In cosmetic products was harmful when they occur in excessive amounts. Evidence studies determinate that in commercially available cosmetics toxic metals might present in amounts creating a danger to human health. The aim of this review is to assess identification of elimination, sources and control of sources, and monitoring countries marketed exposures and hazards can be used to prevent heavy metals toxicity. © 2019, Advanced Scientific Research. All rights reserved

Framework for better living with HIV in England

Duration: April 2007 - May 2009 Sigma Research was funded by Terrence Higgins Trust to co-ordinate the development of a framework to address the health, social care, support and information needs of people with diagnosed HIV in England. It has now been published as the Framework for better living with HIV in England. The over-arching goal of the framework is that all people with diagnosed HIV in England "are enabled to have the maximum level of health, well-being, quality of life and social integration". In its explanation of how this should occur the document presents a road map for social care, support and information provision to people with diagnosed HIV in England. By establishing and communicating aims and objectives, the framework should build consensus and provide a means to establish how interventions could be prioritised and coordinated. The key drivers for the framework were clearly articulated ethical principles, agreed by all those who sign up to it, and an inclusive social development / health promotion approach. Sigma Research worked on the framework with a range of other organisations who sent representatives to a Framework Development Group (see below for membership). The framework is evidence-based and seeks to: Promote and protect the rights and well-being of all people with HIV in England. Maximise the capacity of individuals and groups of people with HIV to care for, advocate and represent themselves effectively. Improve and protect access to appropriate information, social support, social care and clinical services. Minimise social, economic, governmental and judicial change detrimental to the health and well being of people with HIV. Alongside the development of the framework, Sigma Research undertook a national needs assessment among people with diagnosed HIV across the UK called What do you need?. These two projects informed and supported each other. Framework Development Group included: African HV Policy Network Black Health Agency George House Trust NAM NAT (National AIDS Trust) Positively Women Terrence Higgins Trus

Natural source-based graphene as sensitising agents for air quality monitoring

Natural carbon powder has been used as a precursor to prepare two main types of sensitising agents of nitrogen-doped carbon nanoparticles (N-CNPs) and nitrogen-doped graphene quantum dots coupled to nanosheets (N-GQDs-NSs) by using simple treatments of chemical oxidation and centrifugation separation. Characterization based on FTIR, XPS, XRD, Raman spectroscopy, FE-SEM, HR-TEM, AFM, UV-Vis and FL, revealed successful doping carbon nanoparticle with nitrogen with an average plane dimension of 50 nm and relatively smooth surface. The versatility of the prepared samples as sensitising agents was developed and established by exploiting its ability for detection of volatile organic compounds via simple optical fibre based sensing configuration. The comparative experimental studies on the proposed sensor performance indicate fast response achieved at a few tens of seconds and excellent repeatability in exposure to the methanol vapour. The low limit of detection of 4.3, 4.9 and 10.5 ppm was obtained in exposure to the methanol, ethanol and propanol vapours, respectively, in the atmosphere condition. This study gives insights into the chemical/physical mechanism of an enhanced economic optical fibre based gas sensor and illustrates it for diverse sensing applications, especially for chemical vapour remote detection and future air quality monitoring