Significant Papers from the First 50 Years of the Boulder Labs
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Soaring Weather
Chapter 16 SOARING WEATHER While horse racing may be the "Sport of Kings," of the craft depends on the weather and the skill soaring may be considered the "King of Sports." of the pilot. Forward thrust comes from gliding Soaring bears the relationship to flying that sailing downward relative to the air the same as thrust bears to power boating. Soaring has made notable is developed in a power-off glide by a conven contributions to meteorology. For example, soar tional aircraft. Therefore, to gain or maintain ing pilots have probed thunderstorms and moun altitude, the soaring pilot must rely on upward tain waves with findings that have made flying motion of the air. safer for all pilots. However, soaring is primarily To a sailplane pilot, "lift" means the rate of recreational. climb he can achieve in an up-current, while "sink" A sailplane must have auxiliary power to be denotes his rate of descent in a downdraft or in come airborne such as a winch, a ground tow, or neutral air. "Zero sink" means that upward cur a tow by a powered aircraft. Once the sailcraft is rents are just strong enough to enable him to hold airborne and the tow cable released, performance altitude but not to climb. Sailplanes are highly 171 r efficient machines; a sink rate of a mere 2 feet per second. There is no point in trying to soar until second provides an airspeed of about 40 knots, and weather conditions favor vertical speeds greater a sink rate of 6 feet per second gives an airspeed than the minimum sink rate of the aircraft. -
Let Me Just Add That While the Piece in Newsweek Is Extremely Annoying
From: Michael Oppenheimer To: Eric Steig; Stephen H Schneider Cc: Gabi Hegerl; Mark B Boslough; [email protected]; Thomas Crowley; Dr. Krishna AchutaRao; Myles Allen; Natalia Andronova; Tim C Atkinson; Rick Anthes; Caspar Ammann; David C. Bader; Tim Barnett; Eric Barron; Graham" "Bench; Pat Berge; George Boer; Celine J. W. Bonfils; James A." "Bono; James Boyle; Ray Bradley; Robin Bravender; Keith Briffa; Wolfgang Brueggemann; Lisa Butler; Ken Caldeira; Peter Caldwell; Dan Cayan; Peter U. Clark; Amy Clement; Nancy Cole; William Collins; Tina Conrad; Curtis Covey; birte dar; Davies Trevor Prof; Jay Davis; Tomas Diaz De La Rubia; Andrew Dessler; Michael" "Dettinger; Phil Duffy; Paul J." "Ehlenbach; Kerry Emanuel; James Estes; Veronika" "Eyring; David Fahey; Chris Field; Peter Foukal; Melissa Free; Julio Friedmann; Bill Fulkerson; Inez Fung; Jeff Garberson; PETER GENT; Nathan Gillett; peter gleckler; Bill Goldstein; Hal Graboske; Tom Guilderson; Leopold Haimberger; Alex Hall; James Hansen; harvey; Klaus Hasselmann; Susan Joy Hassol; Isaac Held; Bob Hirschfeld; Jeremy Hobbs; Dr. Elisabeth A. Holland; Greg Holland; Brian Hoskins; mhughes; James Hurrell; Ken Jackson; c jakob; Gardar Johannesson; Philip D. Jones; Helen Kang; Thomas R Karl; David Karoly; Jeffrey Kiehl; Steve Klein; Knutti Reto; John Lanzante; [email protected]; Ron Lehman; John lewis; Steven A. "Lloyd (GSFC-610.2)[R S INFORMATION SYSTEMS INC]"; Jane Long; Janice Lough; mann; [email protected]; Linda Mearns; carl mears; Jerry Meehl; Jerry Melillo; George Miller; Norman Miller; Art Mirin; John FB" "Mitchell; Phil Mote; Neville Nicholls; Gerald R. North; Astrid E.J. Ogilvie; Stephanie Ohshita; Tim Osborn; Stu" "Ostro; j palutikof; Joyce Penner; Thomas C Peterson; Tom Phillips; David Pierce; [email protected]; V. -
What Lies Beneath 2 FOREWORD
2018 RELEASE THE UNDERSTATEMENT OF EXISTENTIAL CLIMATE RISK BY DAVID SPRATT & IAN DUNLOP | FOREWORD BY HANS JOACHIM SCHELLNHUBER BREAKTHROUGHONLINE.ORG.AU Published by Breakthrough, National Centre for Climate Restoration, Melbourne, Australia. First published September 2017. Revised and updated August 2018. CONTENTS FOREWORD 02 INTRODUCTION 04 RISK UNDERSTATEMENT EXCESSIVE CAUTION 08 THINKING THE UNTHINKABLE 09 THE UNDERESTIMATION OF RISK 10 EXISTENTIAL RISK TO HUMAN CIVILISATION 13 PUBLIC SECTOR DUTY OF CARE ON CLIMATE RISK 15 SCIENTIFIC UNDERSTATEMENT CLIMATE MODELS 18 TIPPING POINTS 21 CLIMATE SENSITIVITY 22 CARBON BUDGETS 24 PERMAFROST AND THE CARBON CYCLE 25 ARCTIC SEA ICE 27 POLAR ICE-MASS LOSS 28 SEA-LEVEL RISE 30 POLITICAL UNDERSTATEMENT POLITICISATION 34 GOALS ABANDONED 36 A FAILURE OF IMAGINATION 38 ADDRESSING EXISTENTIAL CLIMATE RISK 39 SUMMARY 40 What Lies Beneath 2 FOREWORD What Lies Beneath is an important report. It does not deliver new facts and figures, but instead provides a new perspective on the existential risks associated with anthropogenic global warming. It is the critical overview of well-informed intellectuals who sit outside the climate-science community which has developed over the last fifty years. All such expert communities are prone to what the French call deformation professionelle and the German betriebsblindheit. Expressed in plain English, experts tend to establish a peer world-view which becomes ever more rigid and focussed. Yet the crucial insights regarding the issue in question may lurk at the fringes, as BY HANS JOACHIM SCHELLNHUBER this report suggests. This is particularly true when Hans Joachim Schellnhuber is a professor of theoretical the issue is the very survival of our civilisation, physics specialising in complex systems and nonlinearity, where conventional means of analysis may become founding director of the Potsdam Institute for Climate useless. -
The Power of Light
David N Payne Dedicated to: Guglielmo Marconi and Charles Kao Director ORC University of Southampton 1909 2009 Nobel Laureates in Physics Wireless and optical fibres The power of light GPS systems, synchronous data networks, cell phone telephony, time stamping financial trades Large scale interferometers for telescopes Optical gyroscopes Data centres/computer interconnects Financial traders You can’t beat vacuum for loss, speed of light or stability! The Very Large Telescope Interferometer (VLTI) on Paranal Mountain Data Centre Interconnection Information flow/unit area and latency is key in supercomputers and data centres 20,000 km of fibre per data centre in Facebook alone! Vacuum transit time is 30% lower High-performance: applications in inertial guidance, navigation, platform stabilization, GPS flywheeling, etc. Lower-performance: Consumer / industrial applications in Performancemotion control, industrial limited processing, byconsumer glass electronics, core etc. Periodic lattice of holes Hollow air core Advantage: Typically less than 0.1% optical power in cladding. Ultra-low nonlinearity, lower loss? Vacuum fibre technology Fibres that largely ignore the materials from which they are made Power in glass < 0.01% low nonlinearity Transmission loss < 0.01 dB/m As you wouldLow Latencyexpect (30% from lower) vacuum! Phase insensitive Radiation hard IR transmitting The new anti-resonant fibre 22.3 µm 40.2 µm Width = 359.6 nm 20μm OFC 2016, Los Angeles, PDPTh5A.3 Low Latency data communications • Data transmission at 99.7% the speed of light in vacuum • ‘Only’ 69.4% in a conventional fibre Latency savings (vs conventional fibres): 1m 1.54 ns 100m 154 ns 1km 1.54 µs 100km 154 µs Phase Insensitive Fibres The phase of a signal in a fibre changes with temperature owing to: • Change in refractive index • Change in fibre length • Vacuum fibre temperature sensitivity 2 ps/km/K • 18.5 times smaller than conventional fibres Dr Radan Slavik Slavik et al., Scientific Reports 2015. -
Voltage Standing Wave Ratio Measurement and Prediction
International Journal of Physical Sciences Vol. 4 (11), pp. 651-656, November, 2009 Available online at http://www.academicjournals.org/ijps ISSN 1992 - 1950 © 2009 Academic Journals Full Length Research Paper Voltage standing wave ratio measurement and prediction P. O. Otasowie* and E. A. Ogujor Department of Electrical/Electronic Engineering University of Benin, Benin City, Nigeria. Accepted 8 September, 2009 In this work, Voltage Standing Wave Ratio (VSWR) was measured in a Global System for Mobile communication base station (GSM) located in Evbotubu district of Benin City, Edo State, Nigeria. The measurement was carried out with the aid of the Anritsu site master instrument model S332C. This Anritsu site master instrument is capable of determining the voltage standing wave ratio in a transmission line. It was produced by Anritsu company, microwave measurements division 490 Jarvis drive Morgan hill United States of America. This instrument works in the frequency range of 25MHz to 4GHz. The result obtained from this Anritsu site master instrument model S332C shows that the base station have low voltage standing wave ratio meaning that signals were not reflected from the load to the generator. A model equation was developed to predict the VSWR values in the base station. The result of the comparism of the developed and measured values showed a mean deviation of 0.932 which indicates that the model can be used to accurately predict the voltage standing wave ratio in the base station. Key words: Voltage standing wave ratio, GSM base station, impedance matching, losses, reflection coefficient. INTRODUCTION Justification for the work amplitude in a transmission line is called the Voltage Standing Wave Ratio (VSWR). -
Reflection Coefficient Analysis of Chebyshev Impedance Matching Network Using Different Algorithms
ISSN: 2319 – 8753 International Journal of Innovative Research in Science, Engineering and Technology Vol. 1, Issue 2, December 2012 Reflection Coefficient Analysis Of Chebyshev Impedance Matching Network Using Different Algorithms Rashmi Khare1, Prof. Rajesh Nema2 Department of Electronics & Communication, NIIST/ R.G.P.V, Bhopal, M.P., India 1 Department of Electronics & Communication, NIIST/ R.G.P.V, Bhopal, M.P., India 2 Abstract: This paper discuss the design and implementation of broadband impedance matching network using chebyshev polynomial. The realization of 4-section impedance matching network using micro-strip lines each section made up of different materials is carried out. This paper discuss the analysis of reflection in 4-section chebyshev impedance matching network for different cases using MATLAB. Keywords: chebyshev polynomial , reflection, micro-strip line, matlab. I. INTRODUCTION In many cases, loads and termination for transmission lines in practical will not have impedance equal to the characteristic impedance of the transmission line. This result in high reflections of wave transverse in the transmission line and correspondingly a high vswr due to standing wave formations, one method to overcome this is to introduce an arrangement of transmission line section or lumped elements between the mismatched transmission line and its termination/loads to eliminate standing wave reflection. This is called as impedance matching. Matching the source and load to the transmission line or waveguide in a general microwave network is necessary to deliver maximum power from the source to the load. In many cases, it is not possible to choose all impedances such that overall matched conditions result. These situations require that matching networks be used to eliminate reflections. -
YALE Environmental NEWS
yale environmental NEWS Yale Peabody Museum of Natural History, Yale School of Forestry & Environmental Studies, and Yale Institute for Biospheric Studies fall/winter 2009–2010 · vol. 15, no. 1 Peabody Curator Awarded MacArthur “Genius” Grant page 12 KROON HALL RECEIVES DESIGN AWARDS Kroon Hall, the Yale School of Foresty & Environmental Studies’ new ultra- green home, captured two awards this fall for “compelling” design from the American Institute of Architects. “The way the building performs is essential contrast with the brownstone and maroon moment a visitor enters the building at ground to this beautiful, cathedral-like structure,” the brick of other Science Hill buildings. Glass level, the long open stairway carries the eye up jurors noted. “Part of its performance is the facades on the building’s eastern and western toward the high barrel-vaulted ceiling and the creation of a destination on the campus. The ends are covered by Douglas fi r louvers, which big window high up on the third fl oor, with its long walls of its idiosyncratic, barn-like form are positioned to defl ect unwanted heat and view into Sachem’s Wood. defi ne this compelling building.” glare. The building’s tall, thin shape, combined Opened in January 2009, the 58,200- Designed by Hopkins Architects of Great with the glass facades, enables daylight to pro- square-foot Kroon Hall is designed to use Britain, in partnership with Connecticut-based vide much of the interior’s illumination. And 50% less energy and emit 62% less carbon Centerbrook Architects and Planners, the the rounded line of the standing seam metal dioxide than a comparably sized modern aca- $33.5 million Kroon Hall received an Honor roof echoes the rolling whaleback roofl ine of demic building. -
High Frequency (HF)
Calhoun: The NPS Institutional Archive Theses and Dissertations Thesis Collection 1990-06 High Frequency (HF) radio signal amplitude characteristics, HF receiver site performance criteria, and expanding the dynamic range of HF digital new energy receivers by strong signal elimination Lott, Gus K., Jr. Monterey, California: Naval Postgraduate School http://hdl.handle.net/10945/34806 NPS62-90-006 NAVAL POSTGRADUATE SCHOOL Monterey, ,California DISSERTATION HIGH FREQUENCY (HF) RADIO SIGNAL AMPLITUDE CHARACTERISTICS, HF RECEIVER SITE PERFORMANCE CRITERIA, and EXPANDING THE DYNAMIC RANGE OF HF DIGITAL NEW ENERGY RECEIVERS BY STRONG SIGNAL ELIMINATION by Gus K. lott, Jr. June 1990 Dissertation Supervisor: Stephen Jauregui !)1!tmlmtmOlt tlMm!rJ to tJ.s. eave"ilIE'il Jlcg6iielw olil, 10 piolecl ailicallecl",olog't dU'ie 18S8. Btl,s, refttteste fer litis dOCdiii6i,1 i'lust be ,ele"ed to Sapeihil6iiddiil, 80de «Me, "aial Postg;aduulG Sclleel, MOli'CIG" S,e, 98918 &988 SF 8o'iUiid'ids" PM::; 'zt6lI44,Spawd"d t4aoal \\'&u 'al a a,Sloi,1S eai"i,al'~. 'Nsslal.;gtePl. Be 29S&B &198 .isthe 9aleMBe leclu,sicaf ,.,FO'iciaKe" 6alite., ea,.idiO'. Statio", AlexB •• d.is, VA. !!!eN 8'4!. ,;M.41148 'fl'is dUcO,.Mill W'ilai.,s aliilical data wlrose expo,l is idst,icted by tli6 Arlil! Eurse" SSPItial "at FRIis ee, 1:I.9.e. gec. ii'S1 sl. seq.) 01 tlls Exr;01l ftle!lIi"isllatioli Act 0' 19i'9, as 1tI'I'I0"e!ee!, "Filill ell, W.S.€'I ,0,,,,, 1i!4Q1, III: IIlIiI. 'o'iolatioils of ltrese expo,lla;;s ale subject to 960616 an.iudl pSiiaities. -
Chapter 25: Impedance Matching
Chapter 25: Impedance Matching Chapter Learning Objectives: After completing this chapter the student will be able to: Determine the input impedance of a transmission line given its length, characteristic impedance, and load impedance. Design a quarter-wave transformer. Use a parallel load to match a load to a line impedance. Design a single-stub tuner. You can watch the video associated with this chapter at the following link: Historical Perspective: Alexander Graham Bell (1847-1922) was a scientist, inventor, engineer, and entrepreneur who is credited with inventing the telephone. Although there is some controversy about who invented it first, Bell was granted the patent, and he founded the Bell Telephone Company, which later became AT&T. Photo credit: https://commons.wikimedia.org/wiki/File:Alexander_Graham_Bell.jpg [Public domain], via Wikimedia Commons. 1 25.1 Transmission Line Impedance In the previous chapter, we analyzed transmission lines terminated in a load impedance. We saw that if the load impedance does not match the characteristic impedance of the transmission line, then there will be reflections on the line. We also saw that the incident wave and the reflected wave combine together to create both a total voltage and total current, and that the ratio between those is the impedance at a particular point along the line. This can be summarized by the following equation: (Equation 25.1) Notice that ZC, the characteristic impedance of the line, provides the ratio between the voltage and current for the incident wave, but the total impedance at each point is the ratio of the total voltage divided by the total current. -
Atmospheric Circulation Newsletter of the University of Washington Atmospheric Sciences Department
Autumn 2017 Atmospheric Circulation Newsletter of the University of Washington Atmospheric Sciences Department Studying the effects of Southern African biomass burning on clouds and climate: The ORACLES mission by Professor Robert Wood, Michael Diamond, & Sarah Doherty iny aerosol particles, emitted by Fires, mainly associated with dry season Teverything from tailpipes to trees, float agricultural burning on African savannas, above us reflecting sunlight, seeding clouds and generate smoke, a chemical soup that absorbing solar heat. How exactly this happens includes a large quantity of tiny aerosol – and how it might change in the future particles. This smoke rises high in – is one of the biggest uncertainties the atmosphere driven by strong in how humans are influencing surface heating and then is climate. blown west off the coast; it In September 2016, three then subsides down toward University of Washington the cloud layer over the scientists took part in a southeastern Atlantic large NASA field campaign, Ocean. The interaction Observations of Aerosols between air moisture and Above Clouds and their smoke pollution is complex Interactions, or ORACLES, and not well understood. that is flying research planes Southern Africa produces around clouds off the west coast almost a third of the Earth’s of southern Africa to see how smoke biomass burning aerosol particles, particles and clouds interact. yet the fate of these particles and their ORACLES is a five year program, with influence on regional and global climate is three month-long aircraft field studies, and is poorly represented in climate models. led by Dr. Jens Redemann from NASA Ames The ORACLES experiment is providing Research Center in California. -
The Development of HF Broadcast Antennas
Development of HF Broadcast Antennas FEATURES FEATURES Development of HF Broadcast Antennas the 50% power loss, but made the Rhombic fre - Free Europe and Radio Liberty sites. quency-sensitive, consequently losing the wide- Rhombic antennas are no longer recommend - The Development of HF bandwidth feature. The available bandwidth ed for HF broadcasting as the main lobe is nar - depends on the length of the wire and, using dif - row in both horizontal and vertical planes which ferent lengths of transmission line, it is possible to can result in the required service area not being Broadcast Antennas access two or three different broadcast bands. reliably covered because of the variations in the A typical rhombic antenna design uses side ionosphere. There are also a large number of lengths of several wavelengths and is at a height side lobes of a size sufficient to cause interfer - Former BBC Senior Transmitter Engineer Dave Porter G4OYX continues the story of the of between 0.5-1.0 λ at the middle of the operat - ence to other broadcasters, and a significant pro - development of HF broadcast antennas from curtain arrays to Allis antennas ing frequency range. portion of the transmitter power is dissipated in the terminating resistance. THE CORNER QUADRANT ANTENNA Post War it was found that if the Rhombic Antenna was stripped down and, instead of the four elements, had just two end-fed half-wave dipoles placed at a right angle to each other (as shown in Fig. 1) the result was a simple cost- effective antenna which had properties similar to the re-entrant Rhombic but with a much smaller footprint. -
The 2018 Physics Prize
Nobel Prize Lessons 2018 Teacher’s manuscript – the 2018 Physics Prize The Nobel Prize in Physics • The Nobel Prize in Physics is one of the five prizes founded by Alfred Nobel and awarded on December 10 every year. Before Alfred Nobel died on December 10, 1896, he wrote in his will that the largest part of his fortune should be placed in a fund. The yearly interest on this fund would pay for a prize given to “those who, during the preceding year, shall have conferred the greatest benefit to humankind.” ’ Who is rewarded with the Physics Prize? • This Prize rewards important discoveries or inventions in the field of physics. The development of “wireless telegraphy” (radio) is one example. Another is discoveries about how stars behave. • Guglielmo Marconi and Karl Ferdinand Braun received the Physics Prize in 1909 for the development of radio (“wireless telegraphy”). Subramanyan Chandrasekhar received the 1983 Prize for studying processes of importance to the structure and evolution of the stars. • Three women have been awarded the Physics Prize: • Maria Goeppert Mayer who made the first advanced model of nuclear structure, Marie Curie for pioneering research on radiation and the discovery of the elements radium and polonium and Donna Strickland, awarded with the 2018 Nobel Prize in Physics “for groundbreaking inventions in the field of laser physics”. Physics Prize 2018 • The 2018 Nobel Prize in Physics is all about laser technology. One half of the Prize is being awarded for a tool for capturing and manipulating various particles. The other half rewards a technique for intensifying and speeding up pulsing laser light, beyond what was previously believed possible.