Življenje in tehnika 2/16

letnik LXVII, februar 2016

RAČUNALNIKI V ENEM ČIPU: MIKROKRMILNIKI

Simon Vavpotič

Mikrokrmilnik je majhen računalnik v enem čipu, ki združuje eno ali več procesorskih jeder, delovni in trajni pomnilnik ter različne vhodno-izhodne enote, pogosto pa tudi krmilnik za neposredne pomnilniške prenose. Velikost vgrajenega delovnega oziroma bralno-pisalnega pomnilnika z naključnim dostopom sega od nekaj kilobajtov do nekaj megabajtov, vgrajeni trajni pomnilnik pa je praviloma nekajkrat večji, vendar je namenjen le hrambi programov in vgrajenih podatkov. Mikrokrmilniki nas danes spremljajo že na vsakem koraku -- v pralnih strojih, mikrovalovkah, pečicah, avtomatih za kavo, radijskih in televizijskih sprejemnikih, domačem računalniku, pa tudi v sodobnih avtomobilih, čolnih, ladjah in letalih.


Poldrugo stoletje dinamita

Damir Žniderič

Eksplozivi so poleg kemičnega orožja ena izmed tistih iznajdb kemijske znanosti, za katere bi bilo morda bolje, če nikoli ne bi zapustile laboratorijev. Po drugi strani pa nikakor ne smemo zanemariti njihove uporabnosti v rudnikih, kamnolomih, na različnih gradbiščih in še marsikje. Najbolj znan in v svojem času tudi najbolj uporabljan predstavnik eksplozivov je (bil) dinamit. Tako kot velja za vse eksplozive, tudi ravnanje z dinamitom zahteva izšolanega pirotehnika oziroma minerja, saj ima že majhna nepazljivost lahko katastrofalne posledice. Prav občutljivost teh snovi na udarce, toploto (ali mraz) in stik z drugimi kemikalijami -- z eno besedo na tiste dejavnike, ki bi lahko povzročili njihovo predčasno detonacijo -- je v preteklosti pomenila izziv številnim kemikom pri iskanju čim bolj stabilnih eksplozivov.


Mit o globalnem ogrevanju -- Ali zakaj lahko kljub praznim političnim dogovorom mirno spimo

Mišo Alkalaj

Morda se še kdo izmed bralcev spominja, da je na začetku 70. let prejšnjega stoletja med klimatologi prevladovala hipoteza o globalnem ohlajanju zaradi človeških izpustov aerosolov (prahu ipd.), ki zastirajo pritok sončne svetlobe. Govor je bil celo o skorajšnji ledeni dobi. Redki avtorji, ki so v tistem času v svojih člankih analizirali ogrevalni učinek CO2, so poudarjali predvsem to, da bi človeški izpusti toplogrednih plinov lahko nekoliko ublažili domnevno prihajajočo ohladitev. A ohladitve ni bilo in po letu 1975 se je začelo ogrevati ...

Že kar nekaj časa je minilo od lanskega zgodovinskega podnebnega vrha COP21 v Parizu, in kdor je prebral sklepni dokument, se je lahko prepričal, da se je vse skupaj izteklo kot politična predstava, brez kakršnega koli učinkovitega in obvezujočega dogovora -- torej enako kot vsi prejšnji podnebni vrhi.

Uporabljena literatura za prispevek o globalnem ogrevanju:

[1] Impact of Current Climate Proposals. Bjorn Lomborg, Global Policy 9 NOV 2015. DOI: 10.1111/1758-5899.12295

[1] Paris climate promises will reduce temperatures by just 0.05°C in 2100 (Press release). Bjørn Lomborg, Get The Facts Straight

[1] Christopher R. Scotese: Paleomap Project – Climate History

[1] GEOCARB III: A REVISED MODEL OF ATMOSPHERIC CO2 OVER PHANEROZOIC TIME. ROBERT A. BERNER and ZAVARETH KOTHAVALA, American Journal of Science, Vol. 301, February, 2001, P. 182–204

[1] N. Greenland paleotemperatures derived from GRIP bore hole temperature and ice core isotope profiles. Johnsen, S. J., Dahl-Jensen, D., Dansgaard, W. & Gundestrup, N. Tellus B 47, 624-629

[1] U.S. Senate Committee on Environment & Public Works Hearing Statements, Date: 12/06/2006; Statement of Dr. David Deming, University of Oklahoma, College of Earth and Energy, Climate Change and the Media

[1] Climate Change 2001: IPCC Third Assesment Report

[1] V e-pošti z dne 22. 9. 1999 Keith Briffa piše: »For the record, I do believe that the proxy data do show unusually warm conditions in recent decades. I am not sure that this unusual warming is so clear in the summer responsive data. I believe that the recent warmth was probably matched about 1000 years ago. I do not believe that global mean annual temperatures have simply cooled progressively over thousands of years as Mike appears to and I contend that that there is strong evidence for major changes in climate over the Holocene (not Milankovich) that require explana- tion and that could represent part of the current or future background variability of our climate.«; WikiLeaks - WikiClimatic Research Unit emails, data, models, 1996-2009 - mail 0938031546.txt

[1] Why models run hot: results from an irreducibly simple climate model. Christopher Monckton, Willie W.-H. Soon, David R. Legates3, William M. Briggs. Science Bulletin  2015, Vol. 60  Issue (1): 122-135    DOI: 10.1007/s11434-014-0699-2

[1] Remote Sensing Systems Climate Analysis

[1] Updated list of 66 excuses for the 18-26 year 'pause' in global warming. The Hockey Stick, November 19, 2014

[1] An apparent hiatus in global warming?. Trenberth, K. E. and Fasullo, J. T. (2013). Earth's Future, 1: 19–32. doi:10.1002/2013EF000165

[1] Are the deep oceans cooling? Judith Curry, Climate Etc. July 22, 2014

[1] Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus. Matthew H. England, Shayne McGregor, Paul Spence, Gerald A. Meehl, Axel Timmermann, Wenju Cai, Alex Sen Gupta, Michael J. McPhaden, Ariaan Purich & Agus Santoso. Nature Climate Change 4, 222–227 (2014) doi:10.1038/nclimate2106

[1] The Dresden Codex — the Book of Mayan Astronomy; By Bohumil Böhm and Vladimir Böhm

[1] Sunspots and climate, B. Geerts and E. Linacre 12/’97

[1] Henrik Svensmark (1998). »Influence of Cosmic Rays on Earth’s Climate«. Physical Review Letters 81: 5027–5030. doi:10.1103/PhysRevLett.81.5027

[1] HyperPhysics - The Cloud Chamber

[1] On climate response to changes in the cosmic ray flux and radiative budget; Nir J. Shaviv Racah Institute of Physics, Hebrew University of Jerusalem; JOURNAL OF GEOPHYSICAL RESEARCH, DOI: 10.1029

[1] IPCC Fourth Assessment Report: Climate Change 2007; Climate Change 2007: Synthesis Report; 2.2 Drivers of climate change

[1] ATMOSPHERIC SCIENCE: Cosmic Rays, Clouds, and Climate; K. S. Carslaw, R. G. Harrison, J. Kirkby; Science 29 November 2002: Vol. 298. no. 5599, pp. 1732 – 1737

[1] Correlation demonstrated between cosmic rays and temperature of the stratosphere, Watts Up With That? 22.01.2009

[1] Is the solar system entering a nearby interstellar cloud; Vidal-Madjar, A.; Laurent, C.; Bruston, P.; Audouze, J.; Astrophysical Journal, Part 1, vol. 223, July 15, 1978, p. 589-600.

[1] COSMIC RAYS AND GLOBAL WARMING; A.D. Erlykin, T. Sloan and A.W. Wolfendale; DOI: 10.1051/epn/2010104

[1] The Maunder Minimum and Climate Change: Have Historical Records Aided Current Research?John E. Beckman, and Terence J. Mahoney, Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife, Spain

[1] Solar Scientists Agree That the Sun’s Recent Behavior Is Odd, but the Explanation Remains Elusive; By John Matson, Scientific American, May 27, 2010

[1] The Keeling Curve

[1] Atmospheric Carbon Dioxide Record from Mauna Loa. R.F. Keeling, S.C. Piper, A.F. Bollenbacher and J.S. Walker; DOI: 10.3334/CDIAC/atg.035

[1] TRENDS IN GLOBAL CO2 EMISSIONS 2013 REPORT, PLB Netherlands Environmental Assesment Agency

[1] NOAA Trends in Atmospheric Carbon Dioxide

[1] NASA GISS Surface Temperature Analysis

[1] Presentation Prof. Murry Salby in Hamburg on 18 April 2013

[1] Pehr Björnbom: Rekonstruktion av Murry Salbys teori för att koldioxidökningen är temperaturdriven; Stockholms Initiativet, 24.6.2013

[1] Timing of Atmospheric CO2 and Antarctic Temperature Changes Across Termination III; Nicolas Caillon, Jeffrey P. Severinghaus, Jean Jouzel, Jean-Marc Barnola, Jiancheng Kang, Volodya Y. Lipenkov; SCIENCE VOL 299 14 MARCH 2003, p.1728-1731

[1] Rise in temperatures and CO2 follow each other closely in climate change. Sune Olander Rasmussen, University of Copenhagen, 23 July 2012

[1] Ice Core Records of Atmospheric CO2 Around the Last Three Glacial Terminations. Hubertus Fischer, Martin Wahlen, Jesse Smith, Derek Mastroianni, Bruce Deck; Science Vol. 283 no. 5408 pp. 1712-1714, DOI: 10.1126/science.283.5408.1712

[1] Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. J. R. Petit et al, Nature 399, 429-436 (3 June 1999);  doi:10.1038/20859

[1] Simulating the integrated summertime  Δ 14CO2 signature from anthropogenic emissions over Western Europe. D. Bozhinova, M. K. van der Molen, I. R. van der Velde, M. C. Krol, S. van der Laan, H. A. J. Meijer, and W. Peters; Atmos. Chem. Phys., 14, 7273–7290, 2014 www.atmos-chem-phys.net/14/7273/2014/ doi:10.5194/acp-14-7273-2014

[1] Nicolaus Copernicus: De revolutionibus orbium coelestium. Johannes Petreius (Nürnberg) 1543

[1] BEYOND THE IVORY TOWER: The Scientific Consensus on Climate Change; Naomi Oreskes, Science, 3 December 2004: Vol. 306. no. 5702, p. 1686 DOI: 10.1126/science.1103618

[1] Don’t Believe the Hype Al Gore is wrong. There’s no »consensus« on global warming.; by RICHARD S. LINDZEN, The Wall Street Jornal, July 2, 2006

[1] Joseph Bast and Roy Spencer: The myth of the climate change 97%; What is the origin of the false belief that nearly all scientists agree about global warming? Watts Up With That?, May 30, 2014

[1] SCIENTIFIC CONSENSUS ON CLIMATE CHANGE? by Klaus-Martin Schulte; Reprinted from ENERGY & ENVIRONMENT VOLUME 1 9 No. 2 2008

[1] Quantifying the consensus on anthropogenic global warming in the scientific literature. John Cook1, Dana Nuccitelli, Sarah A Green, Mark Richardson, Bärbel Winkler, Rob Painting, Robert Way, Peter Jacobs and Andrew. Environmental Research Letters, Volume 8, Number 2, May 2013

[1] Climate Consensus and ‘Misinformation’: A Rejoinder to Agnotology, Scientific Consensus, and the Teaching and Learning of Climate Change. David R. Legates , Willie Soon, William M. Briggs, Christopher Monckton of Brenchley. Science & Education April 2015, Volume 24, Issue 3, pp 299-318

[1] Another Ice Age? TIME, June 24, 1974

[1] Margaret Thatcher: Statecraft: Strategies for a Changing World. HarperPerennial March 2003. ISBN 978-0-06-095912-8

[1] Grand promises of Paris climate deal undermined by squalid retrenchments. George Monbiot, The Guardian 12 December 2015

[1] Naomi Klein says Paris Summit “turning into a farce”. Scottish Sceptic 27th November 2015

[1] James Hansen, father of climate change awareness, calls Paris talks 'a fraud'. The Guardian 12 December 2015

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