PSC 1001 Week 13

Document Sample
PSC 1001 Week 13 Powered By Docstoc
					    Inventions & Discoveries
     PSC 1001 CRN# 20701
    Wednesdays 5:30 to 7:20
          BLGG 2 106

              Text Book
Concise History of Science & Invention

    Prof. Anthony Kondoleon
                 Chapter Description
        Concise History of Science & Invention
• Week 13             pages 320 to 341
                   The Information Age
• Era starts the rise of Microsoft
• Important Developments & Programs
  –   Internet & World Wide Web
  –   Intergraded Circuits & MEMS
  –   Fiber Optics
  –   Digital TV, Direct TV & Cable TV
  –   Cell Phones
  –   Space Shuttle
  –   ICBM’s
  –   GPS
  –   Solar Power
  –   Hybrid Cars
  –   MagLev Systems
• Era ends today
                  Microsoft Corporation
• Is a multinational computer technology corporation that develops,
  manufactures, licenses, and supports a wide range of software
  products for computing devices.
• Its most profitable products are the Microsoft Windows operating
  system and the Microsoft Office suite of productivity software.
• The company was founded in 1975, to develop and sell BASIC
  interpreters for the Altair 8800.
• Microsoft rose to dominate the home computer operating system
  market with MS-DOS in the mid-1980s, followed by the Windows
  line of operating systems.
• One commentator notes that Microsoft's original mission was "a
  computer on every desk and in every home, running Microsoft
                      Microsoft Corporation
• In 1985, Microsoft and IBM partnered in the development of a
  different operating system called OS/2.
• Later in1985, Microsoft released its 1st retail version of Windows
• In 1989, Microsoft introduced its office suite, Microsoft Office.
    – The software bundled separate office productivity applications, such as
      Microsoft Word and Microsoft Excel.
•   In May 1990 Microsoft launched Windows 3.0.
•   In 1993, Microsoft released Windows NT 3.1
•   In 1995, Microsoft released Windows 95
•   In August 1995, it launched a major online service, MSN, as a
    direct competitor to AOL.
•   Later in 1997, Internet Explorer 4.0 was released
•   In 2001, Microsoft released Windows XP
•   January 2007, Windows Vista was released
•   Now Windows 7
• Is a global system of interconnected computer networks
  that use the standard Internet Protocol Suite (TCP/IP) to
  serve billions of users worldwide.
• It is a network of networks that consists of millions of
  private and public, academic, business, and government
  networks of local to global scope that are linked by a
  broad array of electronic and optical networking
• The Internet carries a vast array of information resources
  and services, most notably the inter-linked hypertext
  documents of the World Wide Web (WWW) and the
  infrastructure to support electronic mail.
• Traditional communications media, such as telephone
  and television services, are reshaped or redefined using
  the technologies of the Internet, giving rise to services
  such as Voice over Internet Protocol (VoIP) and IPTV.
• Newspaper publishing has been reshaped into Web
  sites, blogging, and web feeds.
• The Internet has enabled or accelerated the creation of
  new forms of interactions through instant messaging,
  Internet forums, and social networking sites
• The Internet has no centralized governance in either
  technological implementation or policies for access
  and usage
• Each constituent network sets its own standards.
• The origins of the Internet go back to the 1960s when the United
  States funded research projects of its military agencies to build
  robust, fault-tolerant and distributed computer networks.
• This research and a period of civilian funding of a new U.S.
  backbone by the National Science Foundation spawned worldwide
  participation in the development of new networking technologies
  and led to the commercialization of an international network in the
  mid 1990s, and resulted in the following popularization of countless
  applications in virtually every aspect of modern human life.
• As of 2009, an estimated quarter of Earth's population uses the
  services of the Internet.
• The Internet Protocol address space and the Domain Name System,
  are directed by a maintainer organization, the Internet Corporation
  for Assigned Names and Numbers (ICANN)
                      World Wide Web
• Is a system of interlinked hypertext
  documents contained on the Internet.
• With a web browser, one can view web
  pages that may contain text, images,
  videos, and other multimedia and
  navigate between them using hyperlinks.
• Using concepts from earlier hypertext
  systems, English physicist Sir Tim          This NeXT Computer was
  Berners-Lee, now the Director of the        used by Sir Tim Berners-
  World Wide Web Consortium, wrote a          Lee at CERN and became
  proposal in March 1989 for what would       the world's first Web server
  eventually become the World Wide Web
• The World-Wide Web was developed to
  be a pool of human knowledge, which
  would allow collaborators in remote sites
  to share their ideas and all aspects of a
  common project.
            World Wide Web (WWW or Web)
• The Web had a number of differences from other hypertext systems.
• The Web required only unidirectional links rather than bi-directional
• This made it possible for someone to link to another resource without
  action by the owner of that resource.
• People generally agree that a turning point for the World Wide Web
  began with the introduction of the Mosaic web browser in 1993.
• The Web enabled the spread of information over the Internet through
  an easy-to-use and flexible format.
• It thus played an important role in popularizing use of the Internet.
• Although the two terms are sometimes conflated in popular use,
  World Wide Web is not synonymous with Internet.
• The Web is an application built on top of the Internet.
World Wide Web
         Intergraded Circuits
• Is a miniaturized electronic circuit that has been
  manufactured in the surface of a thin substrate of
  semiconductor material.
• Integrated circuits are used in almost all electronic
  equipment in use today and have revolutionized the
  world of electronics.
• There are two main advantages of ICs over discrete
  circuits: cost and performance.
    – Cost is low because the chips, with all their components,
      are printed as a unit by photolithography and not
      constructed one transistor at a time.
    – Furthermore, much less material is used to construct a
      circuit as a packaged IC die than as a discrete circuit.
    – Performance is high since the components switch
      quickly and consume little power (compared to their
      discrete counterparts) because the components are small
      and close together.
• As of 2006, chip areas range from a few square
  millimeters to around 350 mm2, with up to 1 million
  transistors per mm2
                      Intergraded Circuits
• The integrated circuit can be credited as being invented by both
  Jack Kilby of T. I. and Robert Noyce of Fairchild Semiconductor
  working independently of each other.
• Kilby recorded his initial ideas concerning the integrated circuit in
  July 1958 and successfully demonstrated the first working
  integrated circuit on September 12, 1958.
   – In his patent application of February 6, 1959, Kilby described his new
     device as “a body of semiconductor material ... wherein all the components
     of the electronic circuit are completely integrated.”
   – Kilby won the 2000 Nobel Prize in Physics for his part of the invention of
     the integrated circuit.
• Robert Noyce also came up with his own idea of integrated circuit,
  half a year later than Kilby.
   – Noyce's chip had solved many practical problems that the microchip
     developed by Kilby had not.
• Noyce's chip, made at Fairchild, was made of silicon, whereas
  Kilby's chip was made of germanium
          Intergraded Circuits
• Both the Minuteman missile and Apollo program needed
  lightweight digital computers for their inertial guidance
    – The Apollo guidance computer led and motivated the
      integrated-circuit technology, while the Minuteman missile
      forced it into mass-production.
• These programs purchased almost all of the available ICs
  from 1960 through 1963, and alone provided the demand
  that funded the production improvements to get the
  production costs from $1000/circuit to merely $25/circuit.
• In 1986 the first one megabit RAM chips were introduced,
  which contained more than one million transistors.
• Microprocessor chips passed the million transistor mark in
  1989 and the billion transistor mark in 2005.
• The trend continues largely unabated, with chips introduced
  in 2007 containing tens of billions of memory transistors.
    Microelectromechanical Systems (MEMS)
• MEMS are made up of components
  between 1 to 100 micrometres in size
  (0.001 to 0.1 mm) and MEMS devices
  generally range in size from 20
  micrometers to a millimeter.
• They usually consist of a microprocessor
  and several components that interact with
  the outside such as microsensors.
• At these size scales, the standard
  constructs of classical physics are not
  always useful.
• Due to MEMS' large surface area to
  volume ratio, surface effects such as
  electrostatics and wetting dominate
  volume effects such as inertia or thermal
    Microelectromechanical Systems (MEMS)
• The potential of very small machines was appreciated long before
  the technology existed that could make them
• MEMS became practical once they could be fabricated using
  modified semiconductor device fabrication technologies, normally
  used to make electronics.
• These include molding and plating, wet and dry etching, electro-
  discharge machining (EDM), and other technologies capable of
  manufacturing very small devices
• MEMS technology can be implemented using a number of
  different materials and manufacturing techniques
   • The choice of which will depend on the device being created
      and the market sector in which it has to operate.
              Fiber Optics
• Is concerned with the design and application
  of optical fibers.
• Optical fibers are widely used in fiber-optic
  communications, which permits
  transmission over longer distances and at
  higher bandwidths than other forms of
• Fibers are used instead of metal wires
  because signals travel along them with less
  loss, and they are also immune to
  electromagnetic interference.
• Fibers are also used for illumination, and are
  wrapped in bundles so they can be used to
  carry images, thus allowing viewing in tight
• Specially designed fibers are used for a
  variety of other applications, including
  sensors and fiber lasers.
                              Fiber Optics
• Light is kept in the core of the optical fiber by total internal reflection.
• This causes the fiber to act as a waveguide.
• Fibers which support many propagation paths or transverse modes are called
  multi-mode fibers (MMF), while those which can only support a single mode
  are called single-mode fibers (SMF).
• Multi-mode fibers generally have a larger core diameter, and are used for
  short-distance communication links and for applications where high power
  must be transmitted.
• Single-mode fibers are used for most communication links longer than
  550 metres (1,800 ft).
• Over short distances, such as networking within a building, fiber saves space in
  cable ducts because a single fiber can carry more data than an electrical cable.
• Fiber is also immune to electrical interference; there is no cross-talk between
  signals in different cables and no pickup of environmental noise.
• Non-armored fiber cables do not conduct electricity, which makes fiber a good
  solution for protecting communications equipment located in high voltage
  environments such as power generation facilities, or metal communication
  structures prone to lightning strikes
Fiber Optics

         The structure of a typical SM fiber.
         1. Core: 8 µm diameter
         2. Cladding: 125 µm dia.
         3. Buffer: 250 µm dia.
         4. Jacket: 400 µm dia
                        Cable Television
• Is a system of providing television to consumers via radio
  frequency signals transmitted to televisions through fixed optical
  fibers or coaxial cables as opposed to the over-the-air method used
  in traditional television broadcasting, via radio waves, in which a
  television antenna is required
• Coaxial cable is often used to transmit cable television into the
• Coaxial cables are capable of bi-directional carriage of signals as
  well as the transmission of large amounts of data.
• Cable television signals use only a portion of the bandwidth
  available over coaxial lines.
• This leaves plenty of space available for other digital services such
  as cable internet, cable telephone and wireless services.
                    Satellite Television
• Is television delivered by the means of communications satellite
  and received by a satellite dish and set-top box.
• In many areas of the world it provides a wide range of channels
  and services, often to areas that are not serviced by cable.
• Satellites used for television signals are generally in either
  naturally highly elliptical,with inclination of +/-63.4 degrees and
  orbital period of about 12 hours, known as Molniya orbit, or
  geostationary orbit 22,300 miles above the earth’s equator.
• A typical satellite has up to 32 transponders for Ku-band and up to
  24 for a C-band only satellite
   – Typically in the C-band (4–8 GHz) or Ku-band (12–18 GHz)
• Satellite TV providers get programming from two major sources:
  International turnaround channels (such as HBO, ESPN and CNN,
  STAR TV, SET, B4U etc) and various local channels
                      Satellite Television
• Most satellite TV customers in developed television markets get
  their programming through a direct broadcast satellite provider,
  such as DISH TV.
• The provider selects programs and broadcasts them to subscribers
  as a package.
• The provider’s goal is to bring channels to the customers television
  in a form that approximates the competition from Cable TV.
• Unlike earlier programming, the provider’s broadcast is completely
  digital, which means it has high picture and stereo sound quality.
• Early satellite television was broadcast in C-band - radio in the 3.4-
  gigahertz (GHz) to 7 GHz frequency range.
• Digital broadcast satellite transmits programming in the Ku
  frequency range (10 GHz to 14 GHz ).
• There are five major components involved in a direct to home
  (DTH) satellite system: the programming source, the broadcast
  center, the satellite, the satellite dish and the receiver.
                  Digital Television (DTV)
• Is the sending and receiving of moving images and sound by
  digital signals, in contrast to the analog signals used by analog TV
• As of late 2009, 10 countries had completed the process of turning
  off analog terrestrial broadcasting.
• Many other countries had plans to do so or were in the process of
  a staged conversion.
• The first country to make a wholesale switch to digital over-the-air
  broadcasting was Luxembourg, in 2006, followed by the
  Netherlands later in 2006, Finland, Sweden, Norway and
  Switzerland in 2007, Belgium and Germany in 2008, and the
  United States in 2009
• Digital television supports many different picture formats defined
  by the combination of size, aspect ratio and interlacing.
• With over-the-air broadcasting in the US, the range of formats can
  be divided into two categories: HDTV and SDTV.
                 Digital Television (DTV)
• HDTV, uses one of two formats: 1280 × 720 pixels in
  progressive scan mode,720p or 1920 × 1080 pixels in
  interlace mode,1080i.
   – Each of these utilizes a 16:9 aspect ratio.
   – HDTV cannot be transmitted over current analog channels.
• Standard definition TV (SDTV), may use one of several
  different formats taking the form of various aspect ratios
  depending on the technology used.
   – For 4:3 aspect-ratio broadcasts, the 640 × 480 format is used,
   – For 16:9 aspect-ratio broadcasts, the 704 × 480 format is used.
• Is an electronic device used for mobile telecommunications
  over a cellular network of specialized base stations known as
  cell sites.
• As opposed to a radio telephone, a cell phone offers full
  duplex communication, automatised calling to and paging
  from a public land mobile network (PLMN), and handoff
  during a phone call when the user moves from one cell to
• Most current cell phones connect to a cellular network
  consisting of switching points and base stations owned by a
  mobile network operator.
• In addition to the standard voice function, current mobile
  phones support many additional services, and accessories,
  such as SMS for text messaging, email, packet switching for
  access to the Internet, gaming, Bluetooth, infrared, camera
  with video recorder and MMS for sending and receiving
  photos and video, MP3 player, radio and GPS.
• Motorola researcher and executive, Martin Cooper, is considered to be the
  inventor of the first practical mobile phone for hand-held use in a non-
  vehicle setting (1973).
• The first citywide cellular network was launched in Japan by NTT in 1979.
• Fully automatic cellular networks were first introduced in the early to mid
  1980s (the 1G generation).
• The Nordic Mobile Telephone (NMT) system was the first truly cellular
  system, since enabled international roaming from start.
• It went online in Denmark, Finland, Norway and Sweden in 1981
• In 1983, Motorola DynaTAC was the first approved mobile phone by FCC
  in the United States.
• The first "modern" network technology on digital 2G (second generation)
  cellular technology was launched by Radiolinja in 1991 in Finland
• The first data services appeared on mobile phones starting with person-to-
  person SMS text messaging in Finland in 1993.
• First trial payments using a mobile phone to pay for a Coca Cola vending
  machine were set in Finland in 1998.
• The first commercial payments were mobile parking trialled in Sweden
  but first commercially launched in Norway in 1999.
• The first commercial payment system to mimic banks and credit cards
  was launched in the Philippines in 1999 simultaneously by mobile
  operators Globe and Smart.
• The first content sold to mobile phones was the ringing tone, first
  launched in 1998 in Finland.
• The first full internet service on mobile phones was i-Mode introduced by
  NTT DoCoMo in Japan in 1999.
•   In 2001 the first commercial launch of 3G (Third Generation)
    was again in Japan by NTT DoCoMo on the WCDMA
•   Until the early 1990s, following introduction of the Motorola
    MicroTAC, most mobile phones were too large to be carried in
    a jacket pocket, so they were typically installed in vehicles as
    car phones.
•   With the miniaturization of digital components and the
    development of more sophisticated batteries, mobile phones
    have become smaller and lighter.
•   The first smartphone was the Nokia 9000 Communicator in
    1996 which incorporated PDA functionality to the basic
    mobile phone at the time.
•   The most commonly used data application on mobile phones is
    SMS text messaging, with 74% of all mobile phone users as
    active users.
•   SMS text messaging was worth over 100 billion dollars in
    annual revenues in 2007 and the worldwide average of
    messaging use is 2.6 SMS sent per day per person across the
    whole mobile phone subscriber base.
                Space Shuttle
• It began operations in 1982 and is scheduled
  to be retired from service in 2010 after 134
• Major missions have included launching
  numerous satellites and interplanetary probes,
  conducting space science experiments, and
  servicing and construction of space stations.
• The Shuttle has been used for orbital space
  missions by NASA, the U.S. Department of
  Defense, the European Space Agency, and
• The United States funded shuttle development
  and operations.
Space Shuttle
        Intercontinental Ballistic Missile (ICBM)
•   Is a long-range (> 5,500 km or 3,500 miles) ballistic
    missile designed for delivering one or more nuclear
•   Modern ICBMs typically carry multiple independently
    targetable reentry vehicles (MIRVs), each of which
    carries a separate nuclear warhead.
•   MIRV was an outgrowth of the rapidly shrinking size
    and weight of modern warheads and the Strategic Arms
    Limitation Treaties which imposed limitations on the
    number of launch vehicles.
•   One of the most important features of the missile is its
•   A key feature of the first computer-controlled ICBM,
    the Minuteman missile, was that it could quickly and
    easily use its computer to test itself.
•   In flight, a booster pushes the warhead and then falls
•   Most modern boosters are solid-fueled rocket motors,
    which can be stored easily for long periods of time.
Intercontinental Ballistic Missile (ICBM)
Intercontinental Ballistic Missile (ICBM)
            Global Positioning System (GPS)
• It provides reliable positioning, navigation, and timing services to
  worldwide users on a continuous basis in all weather, day and
  night, anywhere on or near the Earth.
• GPS is made up of three parts:
   – Between 24 and 32 satellites in Medium Earth Orbit.
   – Four control and monitoring stations on Earth
   – The actual navigation devices users own.
• GPS satellites broadcast signals from space that GPS receivers use
  to provide three-dimensional location (latitude, longitude, and
  altitude) plus the time.
• GPS has become a widely used aid to navigation worldwide, and a
  useful tool for map-making, land surveying, commerce, scientific
  uses, tracking and surveillance, and hobbies such as geocaching
  and waymarking.
              Global Positioning System (GPS)
• A GPS receiver calculates its position by precisely timing the
  signals sent by the GPS satellites high above the Earth.
• Each satellite continually transmits messages which include
    – The time the message was sent
    – Precise orbital information (the ephemeris)
    – The general system health and rough orbits of all GPS satellites.
• The receiver measures the transit time of each message and
  computes the distance to each satellite.
    – Geometric trilateration is used to combine these distances with the satellites'
      locations to obtain the position of the receiver.
• This position is then displayed, sometimes as a moving map
  display or latitude and longitude
    – Elevation information can also be displayed.
•   Many GPS units also show derived information such as direction
    and speed, calculated from position changes
            Global Positioning System (GPS)
• The GPS design originally called for 24 SVs, eight each in three
  circular orbital planes, but this was modified to six planes with four
  satellites each.
• The orbital planes are centered on the Earth, not rotating with
  respect to the stars.
• The six planes have approximately 55° inclination (tilt relative to
  Earth's equator) and are separated by 60° angle along the equator
  from a reference point to the orbit's intersection.
• The orbits are arranged so that at least six satellites are always
  within line of sight from almost everywhere on Earth's surface.
• Orbiting at an altitude of approximately 20,200 kilometers (12,550
  miles), each SV makes two complete orbits each sidereal day,
  repeating the same ground track.
• For military operations, the ground track repeat can be used to
  ensure good coverage in combat zones.
              Global Positioning System (GPS)
• As of March 2008, there are 31 actively
  broadcasting satellites in the GPS constellation, and
  two older, retired from active service satellites kept
  in the constellation as orbital spares.
• The additional satellites improve the precision of
  GPS receiver calculations by providing redundant
• With the increased number of satellites, the
  constellation was changed to a non-uniform
    – Such an arrangement was shown to improve
      reliability and availability of the system,
      relative to a uniform system, when multiple
      satellites fail.
• About ten satellites are visible from any point on
  the ground at any one time.
             Global Positioning System (GPS)
• Each GPS satellite continuously broadcasts a Navigation Message at 50 bit/s
  giving the time-of-week, GPS week number and satellite health information
  (all transmitted in the first part of the message), an ephemeris (transmitted in
  the second part of the message) and an almanac (later part of the message).
• The messages are sent in frames, each taking 30 seconds to transmit 1500 bits.
• Transmission of each 30 second frame begins precisely on the minute and half
  minute as indicated by the satellite's atomic clock according to Satellite
  message format.
• Each frame contains 5 subframes of length 6 seconds and with 300 bits.
• Each subframe contains 10 words of 30 bits with length 0.6 seconds each.
             Global Positioning System (GPS)
• All satellites broadcast at the same two frequencies, 1.57542 GHz (L1 signal)
  and 1.2276 GHz (L2 signal).
• The receiver can distinguish the signals from different satellites because GPS
  uses a code division multiple access (CDMA) spread-spectrum technique where
  the low-bit rate message data is encoded with a high-rate pseudo-random (PRN)
  sequence that is different for each satellite.
• The receiver knows the PRN codes for each satellite and can use this to
  reconstruct the actual message data
• In general, GPS receivers are composed of an antenna, tuned to the frequencies
  transmitted by the satellites, receiver-processors, and a highly-stable clock
  (often a crystal oscillator).
• They may also include a display for providing location and speed information to
  the user.
• A receiver is often described by its number of channels: this signifies how many
  satellites it can monitor simultaneously.
• Originally limited to four or five, this has progressively increased over the years
  so that, as of 2007, receivers typically have between 12 and 20 channels
• Is the field of technology related to the application of solar cells for
  energy by converting solar energy (sunlight, including ultra violet
  radiation) directly into electricity (solar electricity).
• Photovoltaic production has been doubling every 2 years,
  increasing by an average of 48 percent each year since 2002,
  making it the world’s fastest-growing energy technology, and then
  increased by 110% in 2008.
• At the end of 2008, the cumulative global PV installations reached
  15,200 megawatts.
• Roughly 90% of this generating capacity consists of grid-tied
  electrical systems.
• Such installations may be ground-mounted (and sometimes
  integrated with farming and grazing) or built into the roof or walls
  of a building
                        Photovoltaic Cells
• Photovoltaic are best known as a method for generating electric power by
  using solar cells to convert energy from the sun into electricity.
• The photovoltaic effect refers to photons of light knocking electrons into a
  higher state of energy to create electricity.
• The term photovoltaic denotes the unbiased operating mode of a photodiode
  in which current through the device is entirely due to the transduced light
• Virtually all photovoltaic devices are some type of photodiode

      Single Solar Cell                             Solar Cell Array
                   Photovoltaic Cell
• Is a device that uses the photovoltaic effect to generate
  electrical energy using the potential difference that arises
  between materials when the surface of the cell is exposed
  to electromagnetic radiation.
• The photovoltaic cell was developed in 1954 at the Bell
• Photovoltaic cells convert sunlight into DC current and
  are about 30% efficient.
• The average lifespan of a photovoltaic cell is 25-30 years
                            Crystalline Silicon
• The most prevalent bulk material for solar cells is crystalline silicon (c-Si), also
  known as "solar grade silicon".
• Bulk silicon is separated into multiple categories according to crystallinity and
  crystal size in the resulting ingot, ribbon, or wafer.
    • Monocrystalline silicon (c-Si): Single-crystal wafer cells tend to be expensive, and
      because they are cut from cylindrical ingots, do not completely cover a square solar
      cell module without a substantial waste of refined silicon.
         • Hence most c-Si panels have uncovered gaps at the four corners of the
    • Poly- or multicrystalline silicon (poly-Si or mc-Si): made from cast square ingots —
      large blocks of molten silicon carefully cooled and solidified.
         • Poly-Si cells are less expensive to produce than single crystal silicon
           cells, but are less efficient.
    • Ribbon silicon is a type of multicrystalline silicon: it is formed by drawing flat thin
      films from molten silicon and results in a multicrystalline structure.
         • These cells have lower efficiencies than poly-Si, but save on production
           costs due to a great reduction in silicon waste, as this approach does not
           require sawing from ingots.
Silicon Based Solar Cell

              Basic structure of a silicon
              based solar cell and its working

                  The equivalent circuit of
                  a solar cell
               Generations of Solar Cells
• Solar Cells are classified into three generations which
  indicates the order of which each became important.
• At present the first generation technologies are most
  highly represented in commercial production, accounting
  for 89.6% of 2007 production
• First generation cells consist of large-area, high quality
  and single junction devices.
   – The technologies involve high energy and labor inputs which
     prevent any significant progress in reducing production costs.
   – Single junction silicon devices are approaching the theoretical
     limiting efficiency of 31% and achieve an energy payback
     period of 5–7 years
               Generations of Solar Cells
• Second generation materials have been developed to address energy
  requirements and production costs of solar cells.
   – Manufacturing techniques, such as solution deposition, vapor deposition,
     electroplating, and use of Ultrasonic Nozzles are used as they reduce high
     temperature processing significantly.
   – These materials are applied in a thin film to a supporting substrate such as
     glass or ceramics, reducing material mass and costs.
   – These technologies do hold promise of higher conversion efficiencies, but
     commercialization of these technologies has proven difficult
• Third generation technologies aim to enhance poor electrical
  performance of second generation while maintaining very low
  production costs.
   – Current research is targeting conversion efficiencies of 30-60%
     while retaining low cost materials and manufacturing
                   Thin Film Solar Cells
• The production of thin film solar uses specialized layers of sprayed
  on particles and a manufacturing process that aligns these on a
  nano-molecular level in a way that can harness energy from the sun.
• Solar film is applied in sheets or rolls, similar to thermal insulating
• It can be attached to almost anything, and can be used to coat an
  entire skyscrapers worth of windows if desired.
• While efficiencies are low, production costs are too, and the
  cumulative effect on decentralized energy is important
• The factory setup is similar to that used by conventional window
  tinting firms, and the product can be distributed in rolls or sheets of
  thin film solar which can be rapidly distributed.
• Pilot production plants have begun in the last few years and as
  technologies improve efficiencies should increase
            Hybrid Electric Vehicle (HEV)
• HEV combines a conventional
  internal combustion engine
  propulsion system with an electric
  propulsion system.
• The presence of the electric power
  train is intended to achieve either
  better fuel economy than a
  conventional vehicle, or better
• A variety of types of HEV exist, and
  the degree to which they function as
  EVs varies as well.
• The most common form of HEV is
  the hybrid electric car, although
  hybrid electric trucks (pickups and
  tractors) also exist
            Hybrid Electric Vehicle (HEV)
• HEVs make use of efficiency-
  improving technologies such as
  regenerative braking, which
  converts the vehicle's kinetic
  energy into battery-replenishing
  electric energy, rather than
  wasting it as heat energy as
  conventional brakes do.
• Some varieties of HEVs use their
  internal combustion engine to
  generate electricity by spinning an
  electrical generator (known as a
  motor-generator), to either
  recharge their batteries or to
  directly power the electric drive
           Hybrid Electric Vehicle (HEV)
• Many HEVs reduce idle emissions by shutting down the ICE
  at idle and restarting it when needed; this is known as a start-
  stop system.
• A hybrid-electric produces less emissions from its ICE than a
  comparably-sized gasoline car, as an HEV's gasoline engine is
  usually smaller than a pure fossil-fuel vehicle, and if not used
  to directly drive the car, can be geared to run at maximum
  efficiency, further improving fuel economy.
Hybrid Electric Vehicle (HEV)
             Hybrid Electric Vehicle (HEV)
• The hybrid-electric vehicle did not become widely available until
  the release of the Toyota Prius in Japan in 1997, followed by the
  Honda Insight in 1999.
• While initially perceived as unnecessary due to the low cost of
  gasoline, worldwide increases in the price of petroleum caused
  many automakers to release hybrids in the late 2000s;
   – They are now perceived as a core segment of the automotive
     market of the future.
         Hybrid Electric Vehicle (HEV)
• Worldwide sales of hybrid vehicles produced by Toyota
  reached 1.0 million vehicles by May 31, 2007, and the
  2.0 million mark was reached by August 31, 2009, with
  hybrids sold in 50 countries.
• Worldwide sales are led by the Prius, with cumulative
  sales of 1.43 million by August 2009.
• The second-generation Honda Insight was the top-
  selling vehicle in Japan in April 2009, marking the first
  occasion that an HEV has received the distinction.
• American automakers have made development of
  hybrid cars a top priority
                     Parallel Hybrid Systems
• Are most commonly produced at present, have both ICE and an
  electric motor connected to a mechanical transmission.
• Most designs combine a large electrical generator and a motor into
  one unit, often located between the combustion engine and the
  transmission, replacing both the conventional starter motor and the
   – To store power, a hybrid uses a large battery pack with a higher voltage than
     the normal automotive 12 volts.
   – Accessories such as power steering and air conditioning are powered by
     electric motors instead of being attached to the combustion engine.
   – This allows efficiency gains as the accessories can run at a constant speed,
     regardless of how fast the combustion engine is running.
• Parallel hybrids can be categorized by the way the two sources of
  power are mechanically coupled.
   – If they are joined at some axis truly in parallel, the speeds at this axis must be
     identical and the supplied torques add together.
                  Parallel Hybrid Systems
• When only one of the two sources is being used, the other must
  either also rotate in an idling manner or be connected by a one-way
  clutch or freewheel.
   – With cars it is more usual to join the two sources through a
      differential gear.
   – Thus the torques supplied must be the same and the speeds add
      up, the exact ratio depending on the differential characteristics.
   – When only one of the two sources is being used, the other must
      still supply a large part of the torque or be fitted with a reverse
      one-way clutch or automatic clamp.
• Parallel hybrids can be further categorized depending upon how
  balanced the different portions are at providing motive power.
• In some cases, the combustion engine is the dominant portion (the
  electric motor turns on only when a boost is needed) and vice versa.
• Others can run with just the electric system operating.
Parallel Hybrid Systems
                Series or Serial Hybrid
• Have also been referred to as a Range-Extended Electric
  Vehicle (REEV)
   – However, range extension can be accomplished with either
      series or parallel hybrid layouts.
• Series hybrid vehicles are more like a battery electric vehicle
  in design than an internal combustion vehicle or parallel
   – In a series hybrid system, the combustion engine drives an
      electric generator instead of directly driving the wheels.
   – The generator both charges a battery and powers an electric
      motor that moves the vehicle.
   – When large amounts of power are required, the motor
      draws electricity from both the batteries and the generator.
              Series or Serial Hybrid
• A transmission may not be needed at all and if it is
  present it can be far less complex, as electric motors are
  efficient over a wide speed range.
• Some vehicle designs have separate electric motors for
  each wheel.
• Series hybrids can be also fitted with a flywheel or a
  supercapacitor to store regenerative braking energy,
  which can improve efficiency by minimizing the losses
  in the battery
Series or Serial Hybrid
Power-Split Hybrid or Series-Parallel Hybrid
• They incorporate power-split devices allowing for
  power paths from the engine to the wheels that can be
  either mechanical or electrical.
• The main principle behind this system is the
  decoupling of the power supplied by the engine from
  the power demanded by the driver.
• A combustion engine's torque is minimal at lower
  RPMs and, in a conventional vehicle, a larger engine
  is necessary for acceleration from standstill.
• The larger engine, however, has more power than
  needed for steady speed cruising.
Power-Split Hybrid or Series-Parallel Hybrid
• An electric motor, on the other hand, exhibits maximum torque
  at standstill and is well-suited to complement the engine's torque
  deficiency at low RPMs.
• In a power-split hybrid, a smaller, less flexible, and highly
  efficient engine can be used.
• The conventional Otto cycle (higher power density, more low-
  rpm torque, lower fuel efficiency) is often also modified to a
  Miller cycle or Atkinson cycle (lower power density, less low-
  rpm torque, higher fuel efficiency).
• The smaller engine using a more efficient cycle contributes
  significantly to the higher overall efficiency of the vehicle.
Power-Split Hybrid or Series-Parallel Hybrid
                     Fuel Cell Hybrid
• Fuel cell vehicles are often fitted with a battery or super
  capacitor to deliver peak acceleration power and to
  reduce the size and power constraints on the fuel cell
  (and thus its cost)
• This is effectively also a series hybrid configuration
                           Fuel Cell
• Is an electrochemical cell that produces electricity from a fuel
• The electricity is generated through the reaction, triggered in
  the presence of an electrolyte, between the fuel (on the anode
  side) and an oxidant (on the cathode side).
• The reactants flow into the cell, and the reaction products flow
  out of it, while the electrolyte remains within it.
• Fuel cells can operate virtually continuously as long as the
  necessary flows are maintained.
• Fuel cells are different from conventional electrochemical cell
  batteries in that they consume reactant from an external
  source, which must be replenished – an open system.
• By contrast, batteries store electrical energy chemically and
  hence represent a thermodynamically closed system.
                             Fuel Cell
• Many combinations of fuels and oxidants are possible.
• A hydrogen fuel cell uses hydrogen as its fuel and oxygen as its
   – Other fuels include hydrocarbons and alcohols.
   – Other oxidants include chlorine and chlorine dioxide.
• A fuel cell works by catalysis, separating the component electrons
  and protons of the reactant fuel, and forcing the electrons to travel
  through a circuit, hence converting them to electrical power.
• The catalyst typically comprises a platinum group metal or alloy.
• Another catalytic process puts the electrons back in, combining
  them with the protons and oxidant to form waste products
   – Simple compounds like water and carbon dioxide.
                         Fuel Cell
• A typical fuel cell produces a voltage from 0.6 V to
  0.7 V at full rated load.
   – Voltage decreases as current increases
• To deliver the desired amount of energy, the fuel cells
  can be combined in series and parallel circuits, where
  series yields higher voltage, and parallel allows a
  higher current to be supplied.
• Such a design is called a fuel cell stack.
• The cell surface area can be increased, to allow
  stronger current from each cell.
Fuel Cell
• Is a system of transportation that suspends, guides and propels
  vehicles, predominantly trains, using magnetic levitation from
  a very large number of magnets for lift and propulsion.
• This method has the potential to be faster, quieter and
  smoother than wheeled mass transit systems.
• The power needed for levitation is usually not a particularly
  large percentage of the overall consumption, most of the
  power used is needed to overcome air drag, as with any other
  high speed train.
• The highest recorded speed of a Maglev train is 581 kilometers per
  hour (361 mph), achieved in Japan in 2003, 6 kilometers per hour
  (3.7 mph) faster than the conventional TGV speed record.
• This is slower than many aircraft, since aircraft can fly at far
  higher altitudes where air drag is lower, thus high speeds are more
  readily attained.
       Concise History of Science & Invention
• Week 13             pages 320 to 341
• Homework due April 18, 2012

Shared By: