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A Brief History of Radio Broadcasting in Africa
A Brief History of Radio Broadcasting in Africa Radio is by far the dominant and most important mass medium in Africa. Its flexibility, low cost, and oral character meet Africa's situation very well. Yet radio is less developed in Africa than it is anywhere else. There are relatively few radio stations in each of Africa's 53 nations and fewer radio sets per head of population than anywhere else in the world. Radio remains the top medium in terms of the number of people that it reaches. Even though television has shown considerable growth (especially in the 1990s) and despite a widespread liberalization of the press over the same period, radio still outstrips both television and the press in reaching most people on the continent. The main exceptions to this ate in the far south, in South Africa, where television and the press are both very strong, and in the Arab north, where television is now the dominant medium. South of the Sahara and north of the Limpopo River, radio remains dominant at the start of the 21St century. The internet is developing fast, mainly in urban areas, but its growth is slowed considerably by the very low level of development of telephone systems. There is much variation between African countries in access to and use of radio. The weekly reach of radio ranges from about 50 percent of adults in the poorer countries to virtually everyone in the more developed ones. But even in some poor countries the reach of radio can be very high. In Tanzania, for example, nearly nine out of ten adults listen to radio in an average week. -
Rfi/It/2019/9 Sabc Digital Streaming Services
Tender Number: RFI/IT/2019/9 Title: REQUEST FOR INFORMATION: FOR SABC DIGITAL STREAMING SERVICES do REQUEST FOR INFORMATION REQUEST FOR INFORMATION TITLE: RFI/IT/2019/9 SABC DIGITAL STREAMING SERVICES This Request for Information calls for SABC Digital Streaming Services. RFI documents are obtainable from 26th April 2019 from the following websites: Government E-Portal http://www.etenders.gov.za SABC Website http://www.sabc.co.za/sabc/tenders Compulsory Briefing Session will be held Date: 10th May 2019 Time: 11:15 Venue: SABC Radio Park, Ground Floor Auditorium Closing Date: 27th May 2019at 12:00 For enquiries contact Vuyi Manentsa E-mail: [email protected] This RFI is an invitation for person(s) to submit information(s) for the provision of the services as set out in the specification contained herein. Accordingly, this RFI must not be construed, interpreted, or relied upon, whether expressly or implicitly, as an offer capable of acceptance by any person(s), or as creating any form of contractual, promissory or other rights. No binding contract or other understanding for the supply of services will exist between SABC and the respondent. Confidential and Proprietary Information Page 1 of 10 RFI Document Tender Number: RFI/IT/2019/9 Title: REQUEST FOR INFORMATION: FOR SABC DIGITAL STREAMING SERVICES doc SOUTH AFRICAN BROADCASTING SABC SOC LIMITED (“the SABC”) REQUEST FOR INFORMATION (RFI) RFI NUMBER : RFI/IT/2019/9 RFP TITLE : REQUEST FOR INFORMATION: FOR SABC DIGITAL STREAMING SERVICES EXPECTED TIMEFRAME RFI PROCESS EXPECTED DATES RFI Advertisement Date 26th May 2019 RFI document can be accessed on EPortal & RFI Available from SABC Website Compulsory Briefing Session Date & 10th May 2019 @ 11:15 Time Venue for Briefing Session SABC Radio Park, Ground Floor Auditorium RFI Closing Date and Time 27th May 2019 at 12:00 Delivery Venue SABC RADIO PARK Vuyi Manentsa E-mail: [email protected] Contact details The SABC retains the right to change the timeframe whenever necessary and for whatever reason it deems fit. -
Effect of the Solar Wind Density on the Evolution of Normal and Inverse Coronal Mass Ejections S
A&A 632, A89 (2019) Astronomy https://doi.org/10.1051/0004-6361/201935894 & c ESO 2019 Astrophysics Effect of the solar wind density on the evolution of normal and inverse coronal mass ejections S. Hosteaux, E. Chané, and S. Poedts Centre for mathematical Plasma-Astrophysics (CmPA), Celestijnenlaan 200B, KU Leuven, 3001 Leuven, Belgium e-mail: [email protected] Received 15 May 2019 / Accepted 11 September 2019 ABSTRACT Context. The evolution of magnetised coronal mass ejections (CMEs) and their interaction with the background solar wind leading to deflection, deformation, and erosion is still largely unclear as there is very little observational data available. Even so, this evolution is very important for the geo-effectiveness of CMEs. Aims. We investigate the evolution of both normal and inverse CMEs ejected at different initial velocities, and observe the effect of the background wind density and their magnetic polarity on their evolution up to 1 AU. Methods. We performed 2.5D (axisymmetric) simulations by solving the magnetohydrodynamic equations on a radially stretched grid, employing a block-based adaptive mesh refinement scheme based on a density threshold to achieve high resolution following the evolution of the magnetic clouds and the leading bow shocks. All the simulations discussed in the present paper were performed using the same initial grid and numerical methods. Results. The polarity of the internal magnetic field of the CME has a substantial effect on its propagation velocity and on its defor- mation and erosion during its evolution towards Earth. We quantified the effects of the polarity of the internal magnetic field of the CMEs and of the density of the background solar wind on the arrival times of the shock front and the magnetic cloud. -
Predicting the Magnetic Vectors Within Coronal Mass Ejections Arriving at Earth: 2
Space Weather RESEARCH ARTICLE Predicting the magnetic vectors within coronal mass ejections 10.1002/2015SW001171 arriving at Earth: 1. Initial architecture Key Points: N. P.Savani1,2, A. Vourlidas1, A. Szabo2,M.L.Mays2,3, I. G. Richardson2,4, B. J. Thompson2, • First architectural design to predict A. Pulkkinen2,R.Evans5, and T. Nieves-Chinchilla2,3 a CME’s magnetic vectors (with eight events) 1 2 • Modified Bothmer-Schwenn CME Goddard Planetary Heliophysics Institute (GPHI), University of Maryland, Baltimore County, Maryland, USA, NASA 3 initiation rule to improve reliability Goddard Space Flight Center, Greenbelt, Maryland, USA, Institute for Astrophysics and Computational Sciences (IACS), of chirality Catholic University of America, Washington, District of Columbia, USA, 4Department of Astronomy, University of • CME evolution seen by remote Maryland, College Park, Maryland, USA, 5College of Science, George Mason University, Fairfax, Vancouver, USA sensing triangulation is important for forecasting Abstract The process by which the Sun affects the terrestrial environment on short timescales is Correspondence to: predominately driven by the amount of magnetic reconnection between the solar wind and Earth’s N. P. Savani, magnetosphere. Reconnection occurs most efficiently when the solar wind magnetic field has a southward [email protected] component. The most severe impacts are during the arrival of a coronal mass ejection (CME) when the magnetosphere is both compressed and magnetically connected to the heliospheric environment. Citation: Unfortunately, forecasting magnetic vectors within coronal mass ejections remain elusive. Here we report Savani, N. P., A. Vourlidas, A. Szabo, M.L.Mays,I.G.Richardson,B.J. how, by combining a statistically robust helicity rule for a CME’s solar origin with a simplified flux rope Thompson, A. -
Predictability of the Variable Solar-Terrestrial Coupling Ioannis A
https://doi.org/10.5194/angeo-2020-94 Preprint. Discussion started: 26 January 2021 c Author(s) 2021. CC BY 4.0 License. Predictability of the variable solar-terrestrial coupling Ioannis A. Daglis1,15, Loren C. Chang2, Sergio Dasso3, Nat Gopalswamy4, Olga V. Khabarova5, Emilia Kilpua6, Ramon Lopez7, Daniel Marsh8,16, Katja Matthes9,17, Dibyendu Nandi10, Annika Seppälä11, Kazuo Shiokawa12, Rémi Thiéblemont13 and Qiugang Zong14 5 1Department of Physics, National and Kapodistrian University of Athens, 15784 Athens, Greece 2Department of Space Science and Engineering, Center for Astronautical Physics and Engineering, National Central University, Taiwan 3Department of Physics, Universidad de Buenos Aires, Buenos Aires, Argentina 10 4Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA 5Solar-Terrestrial Department, Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of RAS (IZMIRAN), Moscow, 108840, Russia 6Department of Physics, University of Helsinki, Helsinki, Finland 7Department of Physics, University of Texas at Arlington, Arlington, TX 76019, USA 15 8National Center for Atmospheric Research, Boulder, CO 80305, USA 9GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany 10IISER, Kolkata, India 11Department of Physics, University of Otago, Dunedin, New Zealand 12Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan 20 13LATMOS, Universite Pierre et Marie Curie, Paris, France 14School of Earth and Space Sciences, Peking University, Beijing, China 15Hellenic Space Center, Athens, Greece 16Faculty of Engineering and Physical Sciences, University of Leeds, Leeds, UK 17Christian-Albrechts Universität, Kiel, Germany 25 Correspondence to: Ioannis A. Daglis ([email protected]) Abstract. In October 2017, the Scientific Committee on Solar-Terrestrial Physics (SCOSTEP) Bureau established a 30 committee for the design of SCOSTEP’s Next Scientific Program (NSP). -
Identification of Interplanetary Coronal Mass Ejection with Magnetic Cloud in Year 2005 at 1 AU
INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH VOLUME 3, ISSUE 6, JUNE 2014 ISSN 2277-8616 Identification Of Interplanetary Coronal Mass Ejection With Magnetic Cloud In Year 2005 At 1 AU D.S.Burud, R .S. Vhatkar, M. B. Mohite Abstract: Coronal mass ejection (CMEs) propagate in to the interplanetary medium are called as Interplanetary Coronal Mass Ejection (ICME). A set of signatures in plasma and magnetic field is used to identify the ICMEs. Magnetic Cloud (MC) is a special kind of ICMEs in which internal magnetic field configuration is similar like flux rope. We have used the data obtained from ACE Advance Composition Explorer (ACE) based in-situ measurements of Magnetic Field Experiment (MAG) and Solar Wind Electron, Proton and Alpha Monitor (SWEPAM) experiment for the data of magnetic field and plasma parameters respectively. The magnetic field data and plasma parameters of ICMEs used to distinguish them as magnetic cloud, non magnetic cloud. We analyzed eighteen ICMEs observed during January 2005 to December 2005, which is the beginning of declining phase of solar cycle 23. The analysis of magnetic field in the frames of the flux ropes like structure using a Minimum Variance Analysis (MVA) method, and have identified 30% ICMEs in the year 2005, which shows magnetic field rotation in a plane and confirmed as ICMEs with MCs. Keywords: magnetic cloud (MC), interplanetary coronal mass ejection (ICME), minimum variance analysis (MVA). ———————————————————— Introduction:- Table No: 1 Signatures used to identify ICMEs in the Coronal mass ejections (CMEs) are an energetic Heliosphere phenomenon originated in the Sun‘s corona, CMEs are eruptions of plasma and magnetic fields that drive space Sr.no. -
TV on the Afrikaans Cinematic Film Industry, C.1976-C.1986
Competing Audio-visual Industries: A business history of the influence of SABC- TV on the Afrikaans cinematic film industry, c.1976-c.1986 by Coenraad Johannes Coetzee Thesis presented in fulfilment of the requirements for the degree of Master of Art and Sciences (History) in the Faculty of Arts and Sciences at Stellenbosch University Supervisor: Dr Anton Ehlers December 2017 Stellenbosch University https://scholar.sun.ac.za THESIS DECLARATION By submitting this thesis electronically, I declare that the entirety of the work contained therein is my own, original work, that I am the sole author thereof (save to the extent explicitly otherwise stated), that reproduction and publication thereof by Stellenbosch University will not infringe any third party rights and that I have not previously in its entirety or in part submitted it for obtaining any qualification. December 2017 Copyright © 2017 Stellenbosch University All rights reserved Stellenbosch University https://scholar.sun.ac.za ETHICAL CONSIDERATIONS Historical research frequently requires investigations that have ethical dimensions. Although not to the same extent as in medical experimentation, for example, the social sciences do entail addressing ethical considerations. This research is conducted at the University of Stellenbosch and, as such, must be managed according to the institution’s Framework Policy for the Assurance and Promotion of Ethically Accountable Research at Stellenbosch University. The policy stipulates that all accumulated data must be used for academic purposes exclusively. This study relies on social sources and ensures that the university’s policy on the values and principles of non-maleficence, scientific validity and integrity is followed. All participating oral sources were informed on the objectives of the study, the nature of the interviews (such as the use of a tape recorder) and the relevance of their involvement. -
Ten Years of PAMELA in Space
Ten Years of PAMELA in Space The PAMELA collaboration O. Adriani(1)(2), G. C. Barbarino(3)(4), G. A. Bazilevskaya(5), R. Bellotti(6)(7), M. Boezio(8), E. A. Bogomolov(9), M. Bongi(1)(2), V. Bonvicini(8), S. Bottai(2), A. Bruno(6)(7), F. Cafagna(7), D. Campana(4), P. Carlson(10), M. Casolino(11)(12), G. Castellini(13), C. De Santis(11), V. Di Felice(11)(14), A. M. Galper(15), A. V. Karelin(15), S. V. Koldashov(15), S. Koldobskiy(15), S. Y. Krutkov(9), A. N. Kvashnin(5), A. Leonov(15), V. Malakhov(15), L. Marcelli(11), M. Martucci(11)(16), A. G. Mayorov(15), W. Menn(17), M. Mergè(11)(16), V. V. Mikhailov(15), E. Mocchiutti(8), A. Monaco(6)(7), R. Munini(8), N. Mori(2), G. Osteria(4), B. Panico(4), P. Papini(2), M. Pearce(10), P. Picozza(11)(16), M. Ricci(18), S. B. Ricciarini(2)(13), M. Simon(17), R. Sparvoli(11)(16), P. Spillantini(1)(2), Y. I. Stozhkov(5), A. Vacchi(8)(19), E. Vannuccini(1), G. Vasilyev(9), S. A. Voronov(15), Y. T. Yurkin(15), G. Zampa(8) and N. Zampa(8) (1) University of Florence, Department of Physics, I-50019 Sesto Fiorentino, Florence, Italy (2) INFN, Sezione di Florence, I-50019 Sesto Fiorentino, Florence, Italy (3) University of Naples “Federico II”, Department of Physics, I-80126 Naples, Italy (4) INFN, Sezione di Naples, I-80126 Naples, Italy (5) Lebedev Physical Institute, RU-119991 Moscow, Russia (6) University of Bari, I-70126 Bari, Italy (7) INFN, Sezione di Bari, I-70126 Bari, Italy (8) INFN, Sezione di Trieste, I-34149 Trieste, Italy (9) Ioffe Physical Technical Institute, RU-194021 St. -
Diapositiva 1
PAMELAPAMELA SpaceSpace MissionMission FirstFirst ResultsResults inin CosmicCosmic RaysRays Piergiorgio Picozza INFN & University of Rome “ Tor Vergata” , Italy Virtual Institute of Astroparticle Physics June 20, 2008 Robert L. Golden ANTIMATTERANTIMATTER Antimatter Lumps Trapped in our Galaxy antiparticles Antimatter and Dark Matter Research Wizard Collaboration -- BESS (93, 95, 97, 98, 2000) - MASS – 1,2 (89,91) - - Heat (94, 95, 2000) --TrampSI (93) - IMAX (96) -CAPRICE (94, 97, 98) - BESS LDF (2004, 2007) - ATIC (2001, 2003, 2005) - AMS-01 (98) AntimatterAntimatter “We must regard it rather an accident that the Earth and presumably the whole Solar System contains a preponderance of negative electrons and positive protons. It is quite possible that for some of the stars it is the other way about” P. Dirac, Nobel lecture (1933) 4% 23% 73% Signal (supersymmetry)… … and background )(GLAST AMS-02 pCR p+ → ISM p + p+ + p p + + + +pCR pISM →π → μ e → →π0 → γγ e+ → e − Another possible scenario: KK Dark Matter Lightest Kaluza-Klein Particle (LKP): B(1) Bosonic Dark Matter: fermionic final states no longer helicity suppressed. e+e- final states directly produced. As in the neutralino case there are 1-loop processes that produces monoenergetic γγin the final state. P Secondary production (upper and lower limits) Simon et al. ApJ 499 (1998) 250. from χχ Secondary annihilation production (Primary Bergström et production al. ApJ 526 m(c) = 964 (1999) 215 GeV) Ullio : astro- ph/9904086 AntiprotonAntiproton--ProtonProton RatioRatio Potgieter at -
Properties and Geoeffectiveness of Magnetic Clouds During Solar Cycles 23 and 24 N. Gopalswamy1, S. Yashiro1,2, H. Xie1,2, S. Akiyama1,2, and P
Properties and Geoeffectiveness of Magnetic Clouds during Solar Cycles 23 and 24 N. Gopalswamy1, S. Yashiro1,2, H. Xie1,2, S. Akiyama1,2, and P. Mäkelä1,2 1Solar Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 2The Catholic University of America, Washington DC 20064 Corresponding author email: [email protected] Key points • Properties of magnetic clouds in cycle 23 and 24 are significantly different • Anomalous expansion of CMEs cause the magnetic dilution in clouds • Reduced magnetic content and speed of clouds lead to low geoeffectiveness • Accepted for publication in J. Geophys. Res. October 2, 2015 1 Abstract We report on a study that compares the properties of magnetic clouds (MCs) during the first 73 months of solar cycles 23 and 24 in order to understand the weak geomagnetic activity in cycle 24. We find that the number of MCs did not decline in cycle 24, although the average sunspot number is known to have declined by ~40%. Despite the large number of MCs, their geoeffectiveness in cycle 24 was very low. The average Dst index in the sheath and cloud portions in cycle 24 was -33 nT and -23 nT, compared to -66 nT and -55 nT, respectively in cycle 23. One of the key outcomes of this investigation is that the reduction in the strength of geomagnetic storms as measured by the Dst index is a direct consequence of the reduction in the factor VBz (the product of the MC speed and the out-of-the-ecliptic component of the MC magnetic field). The reduction in MC-to-ambient total pressure in cycle 24 is compensated for by the reduction in the mean MC speed, resulting in the constancy of the dimensionless expansion rate at 1 AU. -
Magnetic Cloud Field Intensities and Solar Wind Velocities
GEOPHYSICAL RESEARCH LETTERS, VOL. 25, NO. 7, PAGES 963-966, APRIL 1, 1998 Magnetic cloud field intensitiesand solar wind velocities W. D. Gonzalez, A. L. (",Idade Go•zalez, A. Da.1La,go Institute Nacional de PesquisasEspaciais, She Jos6dos Campos, SP, Brasil B. T. Tsurutani, .1. K. Arballo, G. K. La,klfina,B. Butt, C. M. SpacePla.sma Physics, Jet PropulsionLaboratory, C, Mifornia Institute of Technology,Pasadena, S.-T. Wu (',enterfor SpacePlasma and AeronomicResearch, and Departmentof Mechanicaland Aerospace Engineering,The 11niversityof Alabamain Huntsville,Huntsville Abstract. For the sets of magnetic clo•ds studied in this work [Dungcy,1961 ]. In the aboveexpression, v is the so- we have shown the existence of a relationship between lar wind velocity and Bs is the southward component their peak magneticfield strength and peak velocity of the interplanetary magnetic field (IMF). Gonzalez values, with a clear tendencythat, cloudswhich move and Tsurutani [1987]have establishedempirically that at,higher speeds also possess higher core magnetic field the interplanetary electric field must be greater than 5 strengths.This resultsuggests a possibleintrinsic prop- mV/m for longerthan 3 hoursto createa Dst _• --100 erty of magneticclouds and alsoimplies a geophysical nT magnetic storm. This correspondsto a southward consequence.The relativelylow field strengthsat low field component larger than 12.5 nT for a solar wind velocitiesis pres•mablythe causeof the lackof intense speedof • 400 km/s. stormsduring low speede. jecta. There is alsoan indi- Although the positive correlation })el,weenfast (',MEs cation that, this type of behavior is peculiar for mag- and magnetic storms have been stressedand is reason- netic clouds, whereas other types of non cloud-driver ably well understood, little attention has been paid to gasevents do not,seem to showa similarrelationship, the opposite question, why don't, slow CMEs lead to at least,for the data studied in this paper. -
Social Media for Libraries
Social Media for Libraries Karen du Toit Archivist, Librarian, Blogger Social Media Devotee SABC Radio Archives, South Africa Vizify Bio [email protected] @karentoittoit Bekti Mulatiningsih Independent researcher Indonesia [email protected] @bmulatiningsih 1 Abstract The social media statistics of South Africa reveal an exponential increase in the use of social media. Libraries, as part of a community, cannot ignore this! Social media provide libraries instant and direct connection with their members regardless their geographical location. This paper explores social media use in libraries. The establishment of social media for the SABC Media Libraries is discussed to demonstrate a practical implementation of social media in libraries and archives. Tips and resources, with specific mention to Twitter and Facebook, as well as social media etiquette and social media policy guidelines are supplied. The literature of published articles and Infographic show the changing role of librarians in the social media era and the need for librarians to keep learning and update their skills to accommodate users’ needs. The focus should now be on how well we do social media for the library, not on whether we should do it or not! Keywords: Social Media, Libraries, Web 2.0, Librarians, Archives, SABC, South Africa 2 Introduction The question is not anymore about whether we should do social media, but how well we do social media! We don’t have a choice anymore! (Qualman, 2013) Many organizations and companies use social media and take advantage of it. The reason for using it is that many people use and are active in social media.