This document provides descriptions of several exhibits designed and built by Richard Gagnon for museums. It summarizes several electrical circuit exhibits that allow exploration of concepts like AC vs DC electricity without wires. It also describes electronics exhibits using blocks to explore concepts like amplification and radio transmission. Additional exhibits explore optics, magnetism, heat, sound, and light.
This document is a report on the photovoltaic effect submitted by four students to their professor. It provides an overview of the photovoltaic effect and solar electricity through photovoltaics. The report discusses the origination of photovoltaics from its discovery over 150 years ago. It describes the basic requirements and process for the photovoltaic effect to occur in solar cells. Additionally, it covers the efficiency of solar cells, different types of photovoltaic cells, utilities of photovoltaics and its future scope in India.
Q: What is photovoltaics (solar electricity) or "PV"?
A: What do we mean by photovoltaics? The word itself helps to explain how photovoltaic (PV) or solar
electric technologies work. First used in about 1890, the word has two parts: photo, a stem derived from
the Greek phos, which means light, and volt, a measurement unit named for Alessandro Volta
(1745-1827), a pioneer in the study of electricity. So, photovoltaics could literally be translated as
light-electricity. And that's just what photovoltaic materials and devices do; they convert light energy to
electricity, as Edmond Becquerel and others discovered in the 18th Century.
Q: How can we get electricity from the sun?
A: When certain semiconducting materials, such as certain kinds of silicon, are exposed to sunlight, they
release small amounts of electricity. This process is known as the photoelectric effect. The photoelectric
effect refers to the emission, or ejection, of electrons from the surface of a metal in response to light. It
is the basic physical process in which a solar electric or photovoltaic (PV) cell converts sunlight to
electricity.
Sunlight is made up of photons, or particles of solar energy. Photons contain various amounts of energy,
corresponding to the different wavelengths of the solar spectrum. When photons strike a PV cell, they
may be reflected or absorbed, or they may pass right through. Only the absorbed photons generate
electricity. When this happens, the energy of the photon is transferred to an electron in an atom of the
PV cell (which is actually a semiconductor).
With its newfound energy, the electron escapes from its normal position in an atom of the
semiconductor material and becomes part of the current in an electrical circuit. By leaving its position,
the electron causes a hole to form. Special electrical properties of the PV cell—a built-in electric
field—provide the voltage needed to drive the current through an external load (such as a light bulb).
Q: What are the components of a photovoltaic (PV) system?
A: A PV system is made up of different components. These include PV modules (groups of PV cells),
which are commonly called PV panels; one or more batteries; a charge regulator or controller for a
stand-alone system; an inverter for a utility-grid-connected system and when alternating current (ac)
rather than direct current (dc) is required; wiring; and mounting hardware or a framework.
Q: How long do photovoltaic (PV) systems last?
A: A PV system that is designed, installed, and maintained well will operate for more than 20 years. The
basic PV module (interconnected, enclosed panel of PV cells) has no moving parts and can last more than
30 years. The best way to ensure and extend the life and effectiveness of your PV system is by having it
installed and maintained properly. Experience has shown that most problems occur because of poor or
sloppy system installation.
The document provides an overview of solar energy and photovoltaics. It discusses how solar energy originates from thermonuclear fusion in the sun and is harnessed through various technologies. The key aspects covered include:
- The basic workings of solar cells which use the photovoltaic effect to convert sunlight into electricity through the excitation of electrons in semiconductor materials.
- The development of solar cell technologies from early silicon cells to newer thin-film and multi-junction cells to improve efficiency and reduce costs.
- Applications of solar energy technologies ranging from powering satellites to residential and commercial uses both on and off the electric grid.
Solar energy originates from the thermonuclear fusion reactions of the sun. It represents the entire electromagnetic radiation that reaches Earth and has powered life for millions of years. Solar energy can be used to heat living spaces and water through solar collectors that absorb sunlight and storage systems. Photovoltaics directly convert sunlight into electricity using solar cells made of semiconducting materials like silicon that generate electron-hole pairs when struck by photons. The p-n junction in solar cells allows current to flow in one direction, producing electricity from sunlight.
The document describes the design of a flashlight that is powered solely by the heat from a human hand. It does not require batteries. The design uses Peltier tiles, which generate electricity from temperature differences, to convert the heat from a user's palm into electricity. An oscillator circuit with a step-up transformer is used to boost the low voltage output of the Peltier tiles high enough to power an LED for the flashlight. Testing showed the design was successful and produced a steady beam of light for over 20 minutes in outdoor conditions, demonstrating it can run solely on body heat.
Piezoelectric materials generate an electric charge when subjected to mechanical stress. Quartz was the first material discovered to exhibit piezoelectricity in 1880. There are naturally occurring and man-made piezoelectric materials including crystals, ceramics, and polymers. Piezoelectric materials are used in applications like sensors, lighters, motors, and sonar/ultrasound due to their ability to convert mechanical and electrical energy. They have pros like high output and stiffness but cons like signal decay over long cables or with static pressure.
The document discusses the history and functionality of hand crank flashlights. It describes how Michael Faraday discovered the principles of electromagnetic induction in the 1820s that hand crank flashlights are based on. It explains that hand crank flashlights have two key parts: a permanent magnet that provides a constant magnetic field, and a rotating mechanism that generates a charge when turned. Hand crank flashlights provide light without batteries and are more environmentally friendly.
Witricity is a wireless electricity technology developed at MIT that uses magnetic resonance to efficiently transfer power between two resonant objects over short distances, without wires. It works by generating an oscillating magnetic field from a power source coil which induces a magnetic field in a receiving coil linked by resonance. This resonant coupling allows efficient energy transfer over distances greater than traditional induction methods. The inventors validated the theory by powering a 60-watt light bulb suspended two meters from the power source coil, demonstrating its potential for wirelessly charging electronic devices without contact.
This document is a report on the photovoltaic effect submitted by four students to their professor. It provides an overview of the photovoltaic effect and solar electricity through photovoltaics. The report discusses the origination of photovoltaics from its discovery over 150 years ago. It describes the basic requirements and process for the photovoltaic effect to occur in solar cells. Additionally, it covers the efficiency of solar cells, different types of photovoltaic cells, utilities of photovoltaics and its future scope in India.
Q: What is photovoltaics (solar electricity) or "PV"?
A: What do we mean by photovoltaics? The word itself helps to explain how photovoltaic (PV) or solar
electric technologies work. First used in about 1890, the word has two parts: photo, a stem derived from
the Greek phos, which means light, and volt, a measurement unit named for Alessandro Volta
(1745-1827), a pioneer in the study of electricity. So, photovoltaics could literally be translated as
light-electricity. And that's just what photovoltaic materials and devices do; they convert light energy to
electricity, as Edmond Becquerel and others discovered in the 18th Century.
Q: How can we get electricity from the sun?
A: When certain semiconducting materials, such as certain kinds of silicon, are exposed to sunlight, they
release small amounts of electricity. This process is known as the photoelectric effect. The photoelectric
effect refers to the emission, or ejection, of electrons from the surface of a metal in response to light. It
is the basic physical process in which a solar electric or photovoltaic (PV) cell converts sunlight to
electricity.
Sunlight is made up of photons, or particles of solar energy. Photons contain various amounts of energy,
corresponding to the different wavelengths of the solar spectrum. When photons strike a PV cell, they
may be reflected or absorbed, or they may pass right through. Only the absorbed photons generate
electricity. When this happens, the energy of the photon is transferred to an electron in an atom of the
PV cell (which is actually a semiconductor).
With its newfound energy, the electron escapes from its normal position in an atom of the
semiconductor material and becomes part of the current in an electrical circuit. By leaving its position,
the electron causes a hole to form. Special electrical properties of the PV cell—a built-in electric
field—provide the voltage needed to drive the current through an external load (such as a light bulb).
Q: What are the components of a photovoltaic (PV) system?
A: A PV system is made up of different components. These include PV modules (groups of PV cells),
which are commonly called PV panels; one or more batteries; a charge regulator or controller for a
stand-alone system; an inverter for a utility-grid-connected system and when alternating current (ac)
rather than direct current (dc) is required; wiring; and mounting hardware or a framework.
Q: How long do photovoltaic (PV) systems last?
A: A PV system that is designed, installed, and maintained well will operate for more than 20 years. The
basic PV module (interconnected, enclosed panel of PV cells) has no moving parts and can last more than
30 years. The best way to ensure and extend the life and effectiveness of your PV system is by having it
installed and maintained properly. Experience has shown that most problems occur because of poor or
sloppy system installation.
The document provides an overview of solar energy and photovoltaics. It discusses how solar energy originates from thermonuclear fusion in the sun and is harnessed through various technologies. The key aspects covered include:
- The basic workings of solar cells which use the photovoltaic effect to convert sunlight into electricity through the excitation of electrons in semiconductor materials.
- The development of solar cell technologies from early silicon cells to newer thin-film and multi-junction cells to improve efficiency and reduce costs.
- Applications of solar energy technologies ranging from powering satellites to residential and commercial uses both on and off the electric grid.
Solar energy originates from the thermonuclear fusion reactions of the sun. It represents the entire electromagnetic radiation that reaches Earth and has powered life for millions of years. Solar energy can be used to heat living spaces and water through solar collectors that absorb sunlight and storage systems. Photovoltaics directly convert sunlight into electricity using solar cells made of semiconducting materials like silicon that generate electron-hole pairs when struck by photons. The p-n junction in solar cells allows current to flow in one direction, producing electricity from sunlight.
The document describes the design of a flashlight that is powered solely by the heat from a human hand. It does not require batteries. The design uses Peltier tiles, which generate electricity from temperature differences, to convert the heat from a user's palm into electricity. An oscillator circuit with a step-up transformer is used to boost the low voltage output of the Peltier tiles high enough to power an LED for the flashlight. Testing showed the design was successful and produced a steady beam of light for over 20 minutes in outdoor conditions, demonstrating it can run solely on body heat.
Piezoelectric materials generate an electric charge when subjected to mechanical stress. Quartz was the first material discovered to exhibit piezoelectricity in 1880. There are naturally occurring and man-made piezoelectric materials including crystals, ceramics, and polymers. Piezoelectric materials are used in applications like sensors, lighters, motors, and sonar/ultrasound due to their ability to convert mechanical and electrical energy. They have pros like high output and stiffness but cons like signal decay over long cables or with static pressure.
The document discusses the history and functionality of hand crank flashlights. It describes how Michael Faraday discovered the principles of electromagnetic induction in the 1820s that hand crank flashlights are based on. It explains that hand crank flashlights have two key parts: a permanent magnet that provides a constant magnetic field, and a rotating mechanism that generates a charge when turned. Hand crank flashlights provide light without batteries and are more environmentally friendly.
Witricity is a wireless electricity technology developed at MIT that uses magnetic resonance to efficiently transfer power between two resonant objects over short distances, without wires. It works by generating an oscillating magnetic field from a power source coil which induces a magnetic field in a receiving coil linked by resonance. This resonant coupling allows efficient energy transfer over distances greater than traditional induction methods. The inventors validated the theory by powering a 60-watt light bulb suspended two meters from the power source coil, demonstrating its potential for wirelessly charging electronic devices without contact.
Witricity is a new technology for wireless power transfer using magnetic resonance. Researchers at MIT developed Witricity by using resonant magnetic fields between a transmitter and receiver coil to efficiently transfer energy over distance without wires. The coils are tuned to the same frequency, allowing energy to be wirelessly transferred through resonant coupling of the magnetic fields. Witricity offers highly efficient power transfer over distances much larger than traditional wireless induction methods, with efficiency exceeding 90% over distances from centimeters to meters.
The document discusses different types of solar power technologies and provides examples of solar power installations. It describes how photovoltaic solar panels convert sunlight to electricity using solar cells made of silicon. It also explains concentrated solar power plants use mirrors to focus sunlight and heat a transfer fluid or heat the air to power steam turbines. Examples mentioned include CEPALCO's 1 MW solar power plant in the Philippines, Markham Ontario's rooftop solar installation, Europe's first solar powered train tunnel, and the SolarWorld GT solar car.
The document summarizes a seminar about a hollow flashlight device that harvests energy from human body heat using the Peltier effect. The flashlight contains Peltier tiles mounted on a hollow aluminum tube, with one side heated by a person's hand holding the tube. This creates a temperature differential that the Peltier tiles convert into electricity using thermoelectric effect. This harvested energy from body heat is enough to power an LED light for over 20 minutes. The flashlight provides an advantage over batteries by providing clean, renewable energy from waste heat without using chemicals. Researchers are exploring ways to power small devices like hearing aids using excess body heat.
Microwave ovens and heat lamps both use electromagnetic waves to heat substances but through different mechanisms. Microwave ovens use microwaves to heat water molecules in a substance through rotation, creating friction and heat. Heat lamps use infrared waves to heat the air and substance by emitting heat from their bulbs. Both heat substances but through different types of electromagnetic waves and heating processes.
Electricity can flow in a closed circuit and produce various effects. It produces light by powering light bulbs in a circuit. It produces heat by flowing through a toaster's coils to toast bread. It produces sound by being transformed into sound waves in a radio. Electricity can also produce magnetic effects when passed through a coiled wire to create an electromagnet.
F. Magnetron Deconstruction and Antenna AdaptationKurt Zeller
1) The document discusses deconstructing magnetrons from microwave ovens to use their resonant cavities and tap wires as antennas for experimentation.
2) Connecting the tap wire to an SMA connector was difficult due to material incompatibilities between the copper cavity and stainless steel panel mount.
3) Simulating the magnetron output in EM Pro software proved too complex, so plane wave simulations were used instead. Reducing the magnetron's 900-1000W output power was also explored through circuit designs.
The document discusses the International Ultraviolet Explorer, a satellite that studied astronomical objects emitting ultraviolet light. It carried instruments to observe stars, galaxies, and nebulae in ultraviolet wavelengths. One type of instrument mentioned is a germicidal lamp that gives off short ultraviolet rays.
This document discusses dielectric, piezoelectric, and ferroelectric materials. It defines these materials and explains some of their key properties. Dielectrics have electric dipole moments that result in polarization when an electric field is applied. Piezoelectric materials generate an electric potential or change dimension when mechanically stressed or exposed to an electric field, respectively. Ferroelectrics exhibit spontaneous polarization that can be reversed by an electric field and have applications in memory, capacitors, sensors, and more. Common piezoelectric materials include crystals, ceramics, and polymers like PVDF.
The document discusses different types of ion lasers, focusing on argon lasers. It describes the construction of argon lasers, which consists of mirrors at each end, Brewster windows to reduce reflection loss, a high current power supply, and an argon gas laser tube cooled by water. Argon lasers produce multiple visible wavelengths when argon atoms are excited by an electric current. They require high voltages but can output high power. Applications include scientific research, medicine, and laser light shows.
Piezoelectricity, discovered in the 1880s by the Curie brothers using quartz crystals, allows certain materials to generate an electric charge when subjected to pressure. This piezoelectric effect has been used in diagnostic medical sonography since the late 1950s. Piezoelectric transducers, which contain crystals that convert electrical pulses to mechanical vibrations and vice versa, are at the heart of ultrasound transducers. They enable the transducers to both transmit ultrasound pulses into the body by converting electric signals to sound and receive echo signals by converting returning sound waves back into electrical signals.
The document discusses solar power generation, distribution, and storage from small-scale solar power systems. It describes how solar power works by converting sunlight to electricity through photovoltaic cells or concentrating solar power systems. The document outlines the components of a solar power generation system and discusses photovoltaic effect. It also addresses performance factors, applications, advantages and disadvantages of solar power.
The document discusses how solar panels work to convert sunlight into electrical energy. It begins with an introduction to the sun and how its energy impacts Earth. It then explains that solar panels use silicon photovoltaic cells that directly convert sunlight into electricity through a process where photons dislodge electrons from silicon atoms, generating a flow of electricity. The document concludes by discussing how solar energy can be stored in batteries and used to power individual homes and large solar power plants.
The World runs on Energy. Energy is One of the basic need without which nothing exists. In this paper the role Nantenna system in transforming thermal and solar energy into electricity. Nanoantenna’s Target the mid infrared rays where Photovoltaic cells become inefficient. Infrared radiation is one of the rich energy source. It is also generated by industry people. Solar cells become inefficient during night times or when there is no light but Nantenna even work at night times. The operating mechanism, production is illustrated. Differences, Applications, Advantages and limitations of Nantenna is discussed in the paper. By this cutting-edge technology Free and Clean Energy can be utilized to the maximum extent
1. Static electricity is a stationary electric charge produced by friction that causes sparks or attraction of dust. The triboelectric effect produces charge when objects rub against each other.
2. Materials are either conductors that allow electron flow or insulators that impede electron flow. Common conductors include metals and aqueous salt solutions, while common insulators include plastics, glass, and dry air.
3. Electrostatic induction modifies charge distribution on one material under the influence of a nearby charged object, allowing for charging by proximity without direct contact.
Ferroelectric and piezoelectric materialsZaahir Salam
The document discusses piezoelectric and ferroelectric materials. It defines key terms like dielectric, polarization, and piezoelectric effect. It explains that piezoelectric materials can convert mechanical energy to electrical energy and vice versa. Ferroelectric materials are a special class of piezoelectric materials that exhibit spontaneous polarization without an electric field. Examples of naturally occurring and man-made piezoelectric crystals and ceramics are provided. Common applications of piezoelectric materials include sensors, actuators, generators, and memory devices.
The document proposes a Lunar Solar Power (LSP) system to collect solar power on the moon and transmit it to Earth via microwave beams. The system would consist of solar collectors on the moon's surface that convert sunlight to electricity and then microwave beams. These beams would be transmitted to rectennas on Earth which would convert the microwaves back to electricity for use. The LSP system could provide over 10 terawatts of clean, safe, and reliable solar power to Earth within 15 years as an alternative to current energy sources.
A PRESENTATION ON SOLAR ENERGY.IT INCLUDES:
AN INTRO
HOW WE CAN GENERATE ELECTRICTY AND THE VARIOUS CONCEPTS UNDER ITS WORKING
CONSTRUCTION OF SOLAR PANEL
TYPES OF SOLAR PANEL
BENEFTS OF USING SOLAR ENERGY
HOPE YOU FRIENDS LIKE MY WORK.
An ESP is equipment that uses an electric field to separate suspended particles from flue gas. It works by charging particles in the flue gas and collecting them on collection plates. The performance of an ESP depends on two key particle properties - electrical resistivity, which is a measure of how well particles can accept and transfer charge, and particle size distribution. As particles build up on collection plates, they form a dust layer whose resistivity and thickness determine the electric field strength needed to continue efficiently collecting particles from the flue gas. ESPs can be used to remove particles in waste incineration plants.
An electrostatic precipitator removes dust from flue gases using the attraction between charged dust particles and oppositely charged plates. It works by first charging the dust particles using a corona discharge near discharge electrodes, which creates ions that charge the particles. The charged particles are then attracted to nearby grounded or positively charged collecting electrodes, where they accumulate and are later removed. Electrostatic precipitators use components like electrodes, high voltage transformers, rectifiers, and insulators to generate a strong electrostatic field and separate dust from the flue gas into a hopper for disposal. Controllers help regulate the voltage applied to maximize the dust collection rate over time.
Spring Integration is an integration framework for Java that supports developing applications based on Enterprise Integration Patterns using pipelines of out-of-the-box components. Components interact by passing messages between endpoints through communication channels. Channels connect endpoints and can be defined as Spring beans. Endpoints include adapters, gateways, routers, filters, transformers, splitters and aggregators that process messages.
This document provides an overview of a teach-in on the 2016 US election, including discussing misleading statistics and interpreting data. It summarizes two opposing views of President Obama's economic record using different statistics and timeframes. It also discusses how partisanship can impact views of the economy. Finally, it summarizes four Massachusetts ballot questions on gambling, farm animals, marijuana, and charter schools.
Witricity is a new technology for wireless power transfer using magnetic resonance. Researchers at MIT developed Witricity by using resonant magnetic fields between a transmitter and receiver coil to efficiently transfer energy over distance without wires. The coils are tuned to the same frequency, allowing energy to be wirelessly transferred through resonant coupling of the magnetic fields. Witricity offers highly efficient power transfer over distances much larger than traditional wireless induction methods, with efficiency exceeding 90% over distances from centimeters to meters.
The document discusses different types of solar power technologies and provides examples of solar power installations. It describes how photovoltaic solar panels convert sunlight to electricity using solar cells made of silicon. It also explains concentrated solar power plants use mirrors to focus sunlight and heat a transfer fluid or heat the air to power steam turbines. Examples mentioned include CEPALCO's 1 MW solar power plant in the Philippines, Markham Ontario's rooftop solar installation, Europe's first solar powered train tunnel, and the SolarWorld GT solar car.
The document summarizes a seminar about a hollow flashlight device that harvests energy from human body heat using the Peltier effect. The flashlight contains Peltier tiles mounted on a hollow aluminum tube, with one side heated by a person's hand holding the tube. This creates a temperature differential that the Peltier tiles convert into electricity using thermoelectric effect. This harvested energy from body heat is enough to power an LED light for over 20 minutes. The flashlight provides an advantage over batteries by providing clean, renewable energy from waste heat without using chemicals. Researchers are exploring ways to power small devices like hearing aids using excess body heat.
Microwave ovens and heat lamps both use electromagnetic waves to heat substances but through different mechanisms. Microwave ovens use microwaves to heat water molecules in a substance through rotation, creating friction and heat. Heat lamps use infrared waves to heat the air and substance by emitting heat from their bulbs. Both heat substances but through different types of electromagnetic waves and heating processes.
Electricity can flow in a closed circuit and produce various effects. It produces light by powering light bulbs in a circuit. It produces heat by flowing through a toaster's coils to toast bread. It produces sound by being transformed into sound waves in a radio. Electricity can also produce magnetic effects when passed through a coiled wire to create an electromagnet.
F. Magnetron Deconstruction and Antenna AdaptationKurt Zeller
1) The document discusses deconstructing magnetrons from microwave ovens to use their resonant cavities and tap wires as antennas for experimentation.
2) Connecting the tap wire to an SMA connector was difficult due to material incompatibilities between the copper cavity and stainless steel panel mount.
3) Simulating the magnetron output in EM Pro software proved too complex, so plane wave simulations were used instead. Reducing the magnetron's 900-1000W output power was also explored through circuit designs.
The document discusses the International Ultraviolet Explorer, a satellite that studied astronomical objects emitting ultraviolet light. It carried instruments to observe stars, galaxies, and nebulae in ultraviolet wavelengths. One type of instrument mentioned is a germicidal lamp that gives off short ultraviolet rays.
This document discusses dielectric, piezoelectric, and ferroelectric materials. It defines these materials and explains some of their key properties. Dielectrics have electric dipole moments that result in polarization when an electric field is applied. Piezoelectric materials generate an electric potential or change dimension when mechanically stressed or exposed to an electric field, respectively. Ferroelectrics exhibit spontaneous polarization that can be reversed by an electric field and have applications in memory, capacitors, sensors, and more. Common piezoelectric materials include crystals, ceramics, and polymers like PVDF.
The document discusses different types of ion lasers, focusing on argon lasers. It describes the construction of argon lasers, which consists of mirrors at each end, Brewster windows to reduce reflection loss, a high current power supply, and an argon gas laser tube cooled by water. Argon lasers produce multiple visible wavelengths when argon atoms are excited by an electric current. They require high voltages but can output high power. Applications include scientific research, medicine, and laser light shows.
Piezoelectricity, discovered in the 1880s by the Curie brothers using quartz crystals, allows certain materials to generate an electric charge when subjected to pressure. This piezoelectric effect has been used in diagnostic medical sonography since the late 1950s. Piezoelectric transducers, which contain crystals that convert electrical pulses to mechanical vibrations and vice versa, are at the heart of ultrasound transducers. They enable the transducers to both transmit ultrasound pulses into the body by converting electric signals to sound and receive echo signals by converting returning sound waves back into electrical signals.
The document discusses solar power generation, distribution, and storage from small-scale solar power systems. It describes how solar power works by converting sunlight to electricity through photovoltaic cells or concentrating solar power systems. The document outlines the components of a solar power generation system and discusses photovoltaic effect. It also addresses performance factors, applications, advantages and disadvantages of solar power.
The document discusses how solar panels work to convert sunlight into electrical energy. It begins with an introduction to the sun and how its energy impacts Earth. It then explains that solar panels use silicon photovoltaic cells that directly convert sunlight into electricity through a process where photons dislodge electrons from silicon atoms, generating a flow of electricity. The document concludes by discussing how solar energy can be stored in batteries and used to power individual homes and large solar power plants.
The World runs on Energy. Energy is One of the basic need without which nothing exists. In this paper the role Nantenna system in transforming thermal and solar energy into electricity. Nanoantenna’s Target the mid infrared rays where Photovoltaic cells become inefficient. Infrared radiation is one of the rich energy source. It is also generated by industry people. Solar cells become inefficient during night times or when there is no light but Nantenna even work at night times. The operating mechanism, production is illustrated. Differences, Applications, Advantages and limitations of Nantenna is discussed in the paper. By this cutting-edge technology Free and Clean Energy can be utilized to the maximum extent
1. Static electricity is a stationary electric charge produced by friction that causes sparks or attraction of dust. The triboelectric effect produces charge when objects rub against each other.
2. Materials are either conductors that allow electron flow or insulators that impede electron flow. Common conductors include metals and aqueous salt solutions, while common insulators include plastics, glass, and dry air.
3. Electrostatic induction modifies charge distribution on one material under the influence of a nearby charged object, allowing for charging by proximity without direct contact.
Ferroelectric and piezoelectric materialsZaahir Salam
The document discusses piezoelectric and ferroelectric materials. It defines key terms like dielectric, polarization, and piezoelectric effect. It explains that piezoelectric materials can convert mechanical energy to electrical energy and vice versa. Ferroelectric materials are a special class of piezoelectric materials that exhibit spontaneous polarization without an electric field. Examples of naturally occurring and man-made piezoelectric crystals and ceramics are provided. Common applications of piezoelectric materials include sensors, actuators, generators, and memory devices.
The document proposes a Lunar Solar Power (LSP) system to collect solar power on the moon and transmit it to Earth via microwave beams. The system would consist of solar collectors on the moon's surface that convert sunlight to electricity and then microwave beams. These beams would be transmitted to rectennas on Earth which would convert the microwaves back to electricity for use. The LSP system could provide over 10 terawatts of clean, safe, and reliable solar power to Earth within 15 years as an alternative to current energy sources.
A PRESENTATION ON SOLAR ENERGY.IT INCLUDES:
AN INTRO
HOW WE CAN GENERATE ELECTRICTY AND THE VARIOUS CONCEPTS UNDER ITS WORKING
CONSTRUCTION OF SOLAR PANEL
TYPES OF SOLAR PANEL
BENEFTS OF USING SOLAR ENERGY
HOPE YOU FRIENDS LIKE MY WORK.
An ESP is equipment that uses an electric field to separate suspended particles from flue gas. It works by charging particles in the flue gas and collecting them on collection plates. The performance of an ESP depends on two key particle properties - electrical resistivity, which is a measure of how well particles can accept and transfer charge, and particle size distribution. As particles build up on collection plates, they form a dust layer whose resistivity and thickness determine the electric field strength needed to continue efficiently collecting particles from the flue gas. ESPs can be used to remove particles in waste incineration plants.
An electrostatic precipitator removes dust from flue gases using the attraction between charged dust particles and oppositely charged plates. It works by first charging the dust particles using a corona discharge near discharge electrodes, which creates ions that charge the particles. The charged particles are then attracted to nearby grounded or positively charged collecting electrodes, where they accumulate and are later removed. Electrostatic precipitators use components like electrodes, high voltage transformers, rectifiers, and insulators to generate a strong electrostatic field and separate dust from the flue gas into a hopper for disposal. Controllers help regulate the voltage applied to maximize the dust collection rate over time.
Spring Integration is an integration framework for Java that supports developing applications based on Enterprise Integration Patterns using pipelines of out-of-the-box components. Components interact by passing messages between endpoints through communication channels. Channels connect endpoints and can be defined as Spring beans. Endpoints include adapters, gateways, routers, filters, transformers, splitters and aggregators that process messages.
This document provides an overview of a teach-in on the 2016 US election, including discussing misleading statistics and interpreting data. It summarizes two opposing views of President Obama's economic record using different statistics and timeframes. It also discusses how partisanship can impact views of the economy. Finally, it summarizes four Massachusetts ballot questions on gambling, farm animals, marijuana, and charter schools.
Cloud computing involves using virtualized computing resources like hardware, software, and services to simplify application deployment. There are two levels of access to cloud infrastructure: Infrastructure as a Service (IaaS) provides tools to manage virtual resources, and Platform as a Service (PaaS) provides tools to deploy, scale, and manage applications. Cloud Foundry is an open-source PaaS that can be deployed on various cloud infrastructures. It uses BOSH to create the virtual machines where Cloud Foundry components and applications are deployed. The Cloud Foundry CLI is used to push, scale, and manage applications on the platform.
El documento habla sobre el retiro de un introductor femoral después de un cateterismo. Describe que un paciente de 39 años masculino que fuma sufrió un infarto agudo de miocardio con elevación del segmento ST en la cara inferior y se le colocó un stent resolute de 3.5/30 mm. Recomienda usar guía ultrasónica para la punción femoral y compresión manual como método estándar para cerrar el acceso vascular después del procedimiento.
Prezi es un programa de presentaciones basado en la nube que permite a los usuarios crear presentaciones no lineales mediante el uso de zoom. Fue creado en 2007 por Ádám Somlai-Fischer y desarrollado con el profesor Péter Halácsy y el empresario Peter Arvai. Prezi permite a los usuarios insertar medios como imágenes, texto y videos y diseñar la relación entre los objetos mediante el desplazamiento y el tamaño. Más de 50 millones de personas utilizan actualmente esta herramienta de presentación
Liquid metal design challenge _ Evernote WebJia Wu
Jia and Sherene took on a project to redesign a liquid metal exhibit. They experimented with the exhibit, took notes, conducted research with local experts, and brainstormed for hours on a whiteboard. Finally, they created a presentation with their ideas and presented to Andrew, who loved their final product.
El documento describe un programa de radio llamado "Al Día" que proporciona educación sobre la diabetes a pacientes y sus familias en Tamaulipas, México. El programa ha estado al aire durante 14 años y ha cubierto temas de diabetes con más de 550 invitados expertos. Un estudio encontró que la mayoría de los pacientes diabéticos encuestados escuchaban el programa y creían que mejoraba su tratamiento y control de la diabetes.
Game sense is a constructivist approach to teaching games and sports that focuses on student-centered learning rather than instruction. It emphasizes participation, enjoyment, and appreciation of all skills and abilities rather than the outcome of the game. Game sense encourages questioning, conversation, decision-making, and adaptation of skills during play. It allows games to be modified to suit all students and ability levels. The document discusses how game sense aligns with curriculum outcomes by promoting teamwork, skills, fair play, and cooperation. It is an effective teaching approach that provides equal opportunities for students of all abilities to be involved.
- Les gustó a la gran mayoría los talleres JOURNEY, con una calificaciòn de 3 en la escala de 1(Malo) a 3 (Bueno). De los talleres impartidos, el que más gustó fue el de el Dr. Javier Clavere, la segunda opciòn más votada fue que ningún taller les gustó, superando en votos al taller del Dr. Farouk.
- Les encantarìa tener otro evento similar en un futuro. Los temas a tratar para un evento similar al JOURNEY son diversos, lo cual indica el interés de
Mitos y realidades de los cuidados de la vozLena Trujillo
El documento analiza los principales mitos y realidades sobre los cuidados de la voz. Algunos de los mitos que se desmitifican son que el agua pasa por los pliegues vocales, que ciertos alimentos afectan directamente la voz y que consumir bebidas calientes mejora la voz. También se explican algunas realidades importantes como los efectos de la deshidratación en la voz, el daño que causa fumar y la necesidad de técnica vocal y seguimiento profesional para mantener una buena voz.
Spring Cloud is a collection of projects that simplify application development in cloud environments including microservices architectures. It builds on top of Spring Boot. Spring Cloud Connectors provides a uniform API for cloud applications to obtain information about services like databases and message brokers. Spring Cloud Config provides distributed configuration through a centralized Git repository and REST API. It allows applications to retrieve common and profile-specific settings. The Config Server stores configuration in Git and clients can refresh their settings dynamically through REST endpoints.
This report summarizes what you can find utilizing Quid to understand the issues patients face and their attitudes towards the drugs they use during treatment.
At first
glance, this may seem counterintuitive, as there have been no attacks conducted by ISIS
within Myanmar, and very little attention directed towards the country by ISIS. With
significant international attention directed recently towards the plight of the Muslim Rohingya
population in Myanmar, this has begun to change, with several jihadist groups making public
denunciations of Myanmar, as well as encouraging the Rohingya to take up jihad to defend
their communities. At the time this report was being written (August 2016), Myanmar‟s star
stateswoman Aung San Suu Kyi‟s name had just been included on an assassination list sent
to a Malaysian police station by purported ISIS allegiants inside Malaysia.
Dreamforce16: Rapidly Develop and Deploy Lightning Components with IntellijChris Fellows
Intellij is recommended for developing Lightning components due to its standout features like autocompletion, refactoring support, debugging capabilities, and plugin support. The document provides a crash course on using Illuminated Cloud with Intellij for component documentation, previewing, deployment, and metadata management. It also introduces GridBuddy as an app for building related lists and provides a hands-on example of using GridBuddy with Intellij and Illuminated Cloud to create editable related lists.
Taking out a home loan is a big financial decision that requires careful consideration of several key factors. When meeting with your bank, be sure to ask about interest rates, applicable fees, repayment terms and timeline, as well as penalties for prepayment or late payment. Understanding all costs involved and selecting an option that fits your needs and budget is essential to avoiding future issues with your home loan.
This document provides a snapshot of the VR publishing and monetization landscape in September 2016 based on interviews with over two dozen VR industry experts. It finds that while definitions of VR vary, immersiveness is key. Publishers are creating VR content ranging from 360 videos to interactive experiences, with costs depending on complexity. VR's strengths include immersive storytelling, opportunities for shopping/product demos, and its ability to stir emotions. Experts predict continued growth in the next 24 months as audiences and monetization models expand.
Alternative approaches in comparative educationMaham Naveed
This document discusses the evolution of approaches in comparative education from 1977 to the 1980s. It notes that early journals in the 1970s focused on issues like inequalities between states and how education contributed to social change. In the 1980s, there were four main challenges: 1) to viewing the nation state as the sole framework, 2) to input-output models and reliance on qualifications, 3) to structural functionalism, and 4) to bring attention to new topics of inquiry. It also discusses how education systems were influenced more by external forces like technology and labor markets than internal structures.
Competencias en información para la elaboración del Trabajo Fin de Grado (Fac...Ángel M. Delgado-Vázquez
Presentación del curso Competencias en información para la elaboración del Trabajo Fin de Grado a los estudiantes y profesores de los Grados en Humanidades, Traducción e Interpretación, Geografía e Historia y el doble grado de la Facultad de Humanidades de la Universidad Pablo de Olavide de Sevilla. Biblioteca/CRAI Servicio de Formación de Usuarios
This document provides an introduction to basic electronics concepts including batteries, circuits, series and parallel circuits, resistors, light emitting diodes (LEDs), transistors, and capacitors. It explains key terms like voltage, current, resistance, and capacitance. Several experiments are described that allow the reader to explore these concepts hands-on using a breadboard, battery, resistors, LEDs, transistors, and capacitors. The goal is to help absolute beginners understand fundamental electronics.
A complete list of Physics Laboratory Equipment.docxJeanisilCereno2
The document provides a comprehensive list of common physics laboratory equipment, including their purposes and basic functions. It covers electrical equipment like resistors, rheostats, multimeters; magnetic equipment like compasses and magnets; optical equipment like prisms, lenses, and mirrors; gravity-related equipment like pendulums; waves and sound equipment like tuning forks; heat and thermodynamics equipment like calorimeters; and kinematics equipment like spring balances. The list is intended to familiarize students with the core apparatus used for measurement and experimentation in physics labs.
Lecture 01 Introduction and applications of Electronics & SemiConductors.pdfAthar Baig
The document provides an overview of electronics and semiconductors. It discusses how electronics relies on semiconductors and the key semiconductor materials used - Germanium, Silicon, and Gallium Arsenide. Silicon is highlighted as the most widely used due to its abundance, low cost, and the decades of development into its processing technology. The document also reviews the history of electronics from vacuum tubes to transistors and integrated circuits, and how semiconductors replaced vacuum tubes as the fundamental building blocks of electronic devices.
This document discusses the principles, instrumentation, and applications of UV spectroscopy. It begins with an introduction to UV spectroscopy and its uses in qualitative and quantitative analysis. It then covers the underlying principles of UV absorption, including Lambert's law and Beer's law. The key components of a UV spectrophotometer are described, including radiation sources, monochromators, sample containers, detectors, and recording systems. Finally, common applications of UV spectroscopy are outlined, such as determining functional groups, conjugation, and reaction monitoring.
Electricity is produced through the movement of electrons in conductors like wires. At power stations, coal, gas, or uranium are burned to power generators, which use magnetism and movement to induce electric current in coils. This alternating current is then distributed through the electric grid to homes and businesses. While electric cars may help reduce emissions, producing the electricity to charge them still relies heavily on burning fossil fuels in many places.
Inductive coupling is a common wireless charging method where a magnetic field induced in a receiving coil by a transmitting coil transfers energy through resonance. Researchers have demonstrated transferring power over distances of a few meters using resonating coils tuned to the same frequency, with the potential to wirelessly power all devices in a room. Longer-range proposals involve transmitting solar power from stations on the moon via microwaves and rectennas that convert it to electricity, but such large-scale applications remain theoretical.
Ultraviolet disinfection research document summarizes:
1. UV light is categorized into wavelengths - UV-A, UV-B, and UV-C. UV-C is considered germicidal with the shortest wavelengths below 280nm.
2. Types of UV lamps used for disinfection include cold cathode, hot cathode, and high output germicidal lamps. Cold cathode lamps have longer life while hot cathode lamps require ballasts.
3. UV lamps work by ionizing inert gas like argon inside glass tubes through electrodes heated by ballasts, forming plasma that emits UV light killing microorganisms.
Solar energy originates from thermonuclear fusion reactions in the sun. It represents the entire electromagnetic spectrum that reaches Earth. Solar energy has powered life on Earth for millions of years and offers a renewable source of energy without pollution. Current solar technologies include photovoltaic cells that convert sunlight directly into electricity, as well as solar heating of buildings and water. Research continues to improve efficiency and lower the cost of solar energy.
This document discusses various sensors and transducers. It defines a transducer as a device that converts one form of energy to another, and a sensor as a transducer that detects a characteristic of its environment. It then provides details on different types of transducers and sensors, including antennas, Hall effect sensors, cathode ray tubes, sensors for ionizing radiation, electric current sensors, and proximity sensors. For each it discusses their definition, operating principle, applications and examples. The document is authored by several students and provides a comprehensive overview of key sensors and transducers.
The document summarizes key characteristics and applications of lasers. It describes the properties of coherence, high intensity, high directionality, and monochromaticity that distinguish lasers from other light sources. It also discusses the processes of induced absorption, spontaneous emission, and stimulated emission that enable laser action. Common laser systems like Nd:YAG are described along with their components and working. Finally, the document outlines several industrial, medical, military, scientific, and engineering applications of lasers such as welding, cutting, surgery, communication, and chemical reactions.
This document discusses different types of transducers including optoelectronic devices, temperature transducers, and pressure transducers. It describes common transducers such as photodiodes, thermocouples, strain gauges, capacitive transducers, diaphragms, Bourdon tubes, and proximity sensors. For each transducer, it provides details on construction, working principle, advantages, and disadvantages. The document aims to classify and explain the functioning of various transducers used to convert one form of energy to another.
Witricity is a wireless electricity technology developed at MIT that uses magnetic resonance to efficiently transfer power between two resonant objects over short distances, without wires. It works by generating an oscillating magnetic field from a power source coil which induces a magnetic field in a receiving coil connected to a device. When the coils are tuned to the same frequency, their magnetic fields strongly couple and power is transferred efficiently. This overcomes limitations of traditional induction which requires close proximity. Witricity has potential applications for wirelessly charging devices and could eliminate power cords.
This document provides information about a clap switch circuit project. It includes:
- An introduction describing how the circuit uses a microphone to detect claps and transistors to switch a light on and off.
- Block diagrams showing how the circuit is made up of an audio amplifier, flip-flop circuit, and circuit amplifier sections.
- Descriptions of the main electronic components used in the circuit, including resistors, capacitors, batteries, transistors, and a relay.
This document discusses UV-Visible spectroscopy instrumentation. It describes the key components of a UV-Visible spectrophotometer including light sources like hydrogen discharge lamps, wavelength selectors like monochromators and filters, sample holders, detectors like photomultiplier tubes, and how these components work together in single-beam and double-beam instrument designs to measure absorbance spectra. The learning objectives are to understand the principles and components of UV-Visible spectroscopy instrumentation.
Eddy current inspection uses electromagnetic induction to detect flaws in conductive materials. Alternating current in a probe coil generates a magnetic field that induces eddy currents in the material. Changes in conductivity due to flaws disturb the eddy currents, and are detected by measuring impedance changes in the coil. Eddy current probes come in different configurations and operate in absolute, differential, reflection, or hybrid modes to optimize detection of different flaw types or minimize interference from other factors.
1. The galvanometer is a device used to measure small electric currents, invented in 1820 based on Oersted's discovery that electric currents create magnetic fields.
2. Early galvanometers used a moving magnet, while most modern ones use a moving coil or mirror attached to a coil that moves when a current passes through it.
3. William Thomson improved the mirror galvanometer in 1858, making it highly sensitive enough to detect small currents through transatlantic cables.
1. The galvanometer is a device used to measure small electric currents, invented in 1820 based on Oersted's discovery that electric currents create magnetic fields.
2. Early galvanometers used a moving magnet, while most modern ones use a moving coil or mirror attached to a coil that moves when a current is passed through it.
3. William Thomson improved the mirror galvanometer in 1858, making it highly sensitive enough to detect small currents through transatlantic cables.
1) The document describes an experiment to determine the Stefan's constant using an incandescent lamp and photovoltaic cell.
2) An incandescent lamp is used as a blackbody radiator, and its temperature is varied. The open circuit voltage of a photovoltaic cell facing the lamp is measured at different temperatures.
3) These voltage measurements are then used in the Stefan-Boltzmann equation to calculate the Stefan's constant. Precise measurements of the lamp's glow resistance and photovoltaic cell voltage are required.
1. 1
Exhibits Designed and Built By Richard Gagnon
Oct., 2016
AT THE SCIENCE MUSEUM OF MINNESOTA
Electricity Bench (a.k.a. AC-DC Bench)
Even when experimenting with simple electrical circuits, the wiring quickly becomes a quit
confusing mess. To alleviate that, we mounted various electrical components on to
blocks. The blocks have copper caps mounted at each end, and several small magnets are
arranged inside each cap, so that the blocks can be electrically connected to each other
very quickly. Consequently, there are no wires needed for the circuits and the lay-out of
any circuit construction is easy to follow.
The original bench had a 5 volt DC supply only. Soon after, an AC supply was added, along
with an oscilloscope. Visitors could then explore the difference between AC and DC
electricity. One can see that light bulbs and resistors work the same way with either
supply. But that our AC motor works only on AC and our DC motor works only on DC.
Also available are: rectifiers, LEDs, a capacitor a dismantleable transformer and a solenoid.
Electronics Bench
Numerous electronic circuit boards are mounted to their own plastic blocks. One or more
blocks can be placed on a pair of copper rails which supply power to the blocks. The blocks
can be connected end to end. The inputs are applied to the left of each block; the outputs
are on the right. All signals can be viewed on an oscilloscope. Each block can perform a
task. Among the blocks, there are:
An amplifier: A voltage applied to the input is amplified and the result appears on
the output. The output can be connected to a speaker.
Radio receiver: This one can pick up local stations and the block’s output can be
amplified or otherwise modified.
Radio transmitter: an audio signal can be applied to the input. The output can be
picked up (wirelessly) by the receiver.
Light detector: A light source will cause this block to produce a voltage at its output.
It will also pick up signals from an ordinary TV remote.
Oscillators: There are two. One works in the audio range, the other in the sub-
audio. They can each be connected to each other.
In the electronics engineering world, we often buy and connect up various electronic
devices in some way so as to achieve some result. We often don’t need to understand just
how the devices (or our blocks) work. We only need to understand what inputs are needed
to get a desired output.
(Many people worked on this project including Aaron Heidgerken, Jim Willmore and Chris
Burda.)
2. 2
Electro- larynx
These devices are used by people who have lost use of their vocal chords. Griffin
Laboratories donated one their devices, which we modified extensively. The Griffin model
has a pitch control, so now, when visitors learn how to use our version, they can get a good
sense of how the larynx, throat and mouth all work together to generate speech.
Optics Bench
This exhibit works much like the familiar students' optics bench, with these differences:
The lenses, pin-holes, screens, etc. are permanently mounted to their respective holders.
The holders are made so that all of the various optical components can be brought right
next to each other when they are slid along the bench. Instead of a fixed scale mounted
to the bench, a pair of tape-measures have been mounted together in a way which makes
is quite easy to measure distances between various elements.
Numerous optical phenomenon can be investigated: The simple projection of a real
image, the effect of stops, the rule for magnification, the workings of microscopes,
telescopes, pin-hole cameras, and other devices.
(Built in collaboration with Kit Kube.)
RC Bench
The user may arrange resistors, capacitors and a neon bulb so that the bulb flashes
regularly. One of the capacitors consists of nothing more than two 15" x 15" metal plates
separated by a thin sheet of plastic. A resistor may be constructed by drawing a heavy
pencil line on a piece of paper and then placing it in the circuit. A special, high impedance
(109 ohms) volt meter was constructed to monitor voltages in the circuit.
(Built in collaboration with Mike Maus and Tom Gagnon.)
Flame Spectrometer
The visitor may introduce small samples of any of six chemical solutions into a Bunsen
burner flame. The flame then turns color. The color, which is due to the ionization of the
chemical elements, indicates what elements are in the solution. The flame may be viewed
through a spectroscope.
Crackometer
This device demonstrates the importance of wearing a helmet when riding a bicycle. The
visitor causes a 1 pound hammer to fall and strike a steel plate. Strain gages on the plate
measure the force of the hammer blow. The visitor may insert a 1/4" pad between the
hammer and the plate. When the hammer falls again, there is a dramatic difference in the
force that the plate experiences. This is because when the pad is in place, the
decelerating force of the hammer is spread over a longer time. The peak force on the
plate is displayed on a large meter.
3. 3
Building Insulation Exhibit
All materials that we use to insulate our buildings are in fact much poorer insulators than
air. The exhibit shows that the insulating material's job is to keep the air from moving. If
the air cannot move (by convection or just by the wind) then it won’t transfer heat by
conduction to a building’s walls. Heat transfer by radiation is also explored.
Electrocardiograph
The visitor grasps two copper handles. The heart's electrical signal is displayed on a
storage oscilloscope. The oscilloscope's image can be frozen by a visitor’s moving one of
the handles forward. The visitor can see and identify the characteristic parts of the wave
form.
Transformer Bench
The visitor may assemble a transformer in several different ways. The incoming voltage
can be "transformed" into a high or low voltage. We included a watt meter. The meter
shows the inefficiency of our home-made transformer and shows that we never get
something for nothing. Voltage or current can be increased when passed through
transformers, but not the wattage.
Magnetizer Bench
Different metal rods can be placed in a wire coil. A large current (900 amps) passes briefly
through the coil windings. This will magnetize some rods but not others. The rods can
also be demagnetized.
Transmission Lines
This exhibit demonstrates why our power company transmits electrical power at such very
high voltages. It also shows why our power is ac, not dc. Small houses with light bulbs in
them can be connected via a longish "transmission line" either directly to a 5 volt source.
Or the houses can be connected in a more complicated way: the source is first stepped
up by a transformer to 40 volts, then stepped down to the usable 5 volts.
Strobe Light
A strobe light was mounted to a table so that several devices can be viewed while they are
in operation. Devices include a sewing machine, an electric toothbrush and a simple
spinning disk.
Strobe Wheels
Instead of viewing objects with a strobe light, visitors view objects through a spinning disk
with a radial slit in it. This allows viewers to see that the light emitting from neon signs,
fluorescent lights and television screens are changing rapidly over time. Many people are
quite surprised to see that a picture on a television screen is in fact dark most of the time,
and that the picture we see is generated by a bright line scanning from top to bottom.
4. 4
Musical Spots
We felt that we should have a wheelchair-accessible version of the Musical Stairs. We
needed a clearly defined path, and we needed a reliable way to detect people when they
traveled on it. The solution to the first need was to use small theater lights to make
several well-defined light-spots on the floor. The solution to the second problem was to
make small telescopes, each of which would look down on one light spot. If a visitor
stepped on a light spot, a photo-detector would see the shadow. This causes a musical
note to be sounded, and for the light-spot to go off for a few seconds.
Blink Comparator
Since the earliest days of photography, astronomers have used blink comparators to
watch for changes in the night sky. The planet, Pluto, for example, was found this way. A
photograph was taken of an area of the sky. Weeks later, another photograph was taken
of the same place. The two photographs were placed in a blink comparator. This machine
allows an astronomer to switch rapidly between the view of one photograph and then the
other. Pluto appeared as a single tiny speck that seemed to jump back and forth as the
photographs were switched. Our blink comparator allows visitors to view several pairs of
photographs and attempt to find some change between each pair.
Electrostatic Smoke Trap
One of the several pollutants generated by coal-fired power plants is a fine dust of
unburnable minerals. These can be trapped by subjecting the flue gases to a high voltage.
The micrometer sized particles will take on enough charge so that they can be drawn to
plates of an opposite charge where the particles stick.
In the exhibit, the public can turn our smoke generator on, watch smoke rise into the air,
and then turn on the electrostatic trap. One then sees that the smoke is trapped.
5. 5
EXHIBITS PROJECTS AT THE EXPLORATORIUM:
Mathematics
Brazil Nuts
When a box filled with small parts is shaken, large objects tend to rise to the top, even if
the large ones are denser than the small ones. This exhibit has been built to show this in
two dimensions. (Built in collaboration with Claire Pillsbury)
Catenary Arch
Visitors construct a free standing arch from non-interlocking blocks.
Fading Motion (a.k.a. Sand Pendulum)
This pendulum is viscous-damped. While it swings over a conveyer belt, a stream of sand
runs out of the pendulum bob (actually a funnel) and draws a damped sine wave on the
belt. The damping is exponential.
Hyperbolic Slot
A three foot long, straight stick can be made to pass through a curved slot. This can
happen because, as the stick is made to move, it describes a hyperboloid in space.
Non-Round Rollers
A flat board rolls smoothly over the tops of two rollers. The rollers are obviously not
round. It turns out that a circle is but one member of a whole family of shapes with the
property of having a constant width.
Planimeter
Planimeters are devices used to measure the areas of irregular shapes drawn on paper. A
highly museumized planimeter is displayed. In explaining its operation, some of the basic
principles of calculus are shown.
Scaling
It is surprising to most people to discover that large and small structures behave very
differently, even though they are exact scale models of each other. In this exhibit, four
plastic strips are mounted on a common block. Each strip is a scale model of its neighbor.
When the block is rotated, the small strip can easily be made to stand on end like a blade
of grass. The largest strip cannot stand at all.
Square Wheels
A car with square wheels will roll smoothly over a surface. However, the surface cannot
be flat. For polygon-shaped wheels, the surface must be a series of catenaries. (Built in
collaboration with Jack Tessman)
6. 6
Mechanics
Bernoulli Levitator
A blower blows air downward, out of the ceiling of this exhibit. When a 10 inch plate is
pushed up close to the hole, the plate is suddenly supported by the air stream, and held
close to the ceiling. Bernoulli’s principle that a fluid’s pressure will decrease as the fluid’s
speed increases is demonstrated.
Bicycle Wheel Gyro
Various gyroscopic effects can be seen, using bicycles wheels mounted to handles. We
basically took a classroom demonstration and turned it into an exhibit. (Built in
collaboration with Jeff Adams)
Doppler Exhibit
A "Sonalert" noise maker is attached to a belt which runs over pulleys 20 feet apart, one
above the other. When a visitor turns a crank, the noise maker travels towards and away
from the visitor, and the Doppler shift can easily be heard.
Falling Feather
A feather, along with a second, much denser, object, can be made to fall in a 6 ft. long
evacuated tube. That the two objects fall at the same rate in a vacuum can be clearly
seen. (Built in collaboration with Tom Tompkins)
Foucault's First Pendulum
A thin, two ft. long rod has one end mounted to a heavy base. The visitor plucks the free
end so that it oscillates. The base can be rotated, so that it can be seen that the plane of
oscillation of the rod stays fixed while the base is rotated beneath it, thereby
demonstrating how large "Foucault Pendulum" exhibits can reveal the rotation of the
earth.
Pendulum Table
Behaviors of simple pendulums are shown. A clock escapement is also demonstrated.
Resonant Pendulum
The visitor can set in motion a large concrete pendulum by pulling on it with very weak
magnet, provided that the pulling is in phase with motion of the pendulum. The
pendulum hangs by a 30 ft. cable. (Built in collaboration with Joe Ansel)
7. 7
Heat and Temperature
Curie-Point Motor
A light shines on the rim of a wheel. The rim is made of an alloy whose curie-point is only
a little above room temperature. The heat from the light is enough raise the metal above
the curie-point in just one spot. There is a magnet near this spot, and because of an
unequal pull of the magnet, the wheel is made to turn continuously. (The originator of
this device is not known to us.)
Thermocouples
The heat from one’s hand creates a weak current through the junction of dissimilar
metals. Also the reverse effect is shown: current forced through a junction will pump
heat, giving us a solid-state refrigerator.
Water Freezer
A small quantity of water is made to freeze by evaporating part of it in a vacuum
chamber. Boiling water, covered with ice, may be observed. Visitors may open the
chamber and remove the ice.
Electricity and Magnetism
Magnetic Lines of Force
Steel rods have been inserted into ½” acrylic balls. The balls are placed in 25 spaces in a
sealed acrylic box which is filled with oil that matches the index of refraction of the
plastics. The result is that when the box is brought near a large permanent magnet, the
magnet lines of force can be easily seen in three dimensions.
Magnetic Sand
...consists of a large permanent magnet mounted in a shallow tray. The tray contains
magnetic sand (magnetite). Visitors are free to play with and observe the interaction
between the sand and magnet. The magnetite is beach sand so the grains are quite
spherical. Consequently, the sand has a very pleasant feel, quite unlike the gritty feel of
iron filings.
Sand Sorter
The public is recruited to turn a crank and sort our magnetic sand from beach-sand.
8. 8
Physics of Light
Blue Sky
A beam of white light enters a clear plastic tube from one end. The tube, which is filled
with a suspension of protein gelatin, scatters polarized blue light at right angles to the
incoming beam. The blue light is due to Rayleigh scattering, the same process that causes
the sky to be blue.
Michelson-Morely Interferometer
The operation of this famous device is shown. In one experiment, air can be removed
from a small chamber mounted on the interferometer, and the resultant change of the
speed of light in the chamber can be seen. (built in collaboration with Dave Flemming and
Charles Gloriosso)
Stress Analyzer
Using polarizers and a quarter-wave plate, mechanical stresses can be seen in clear plastic
models of objects.
Zoom Lens
...shows the movement of the two lenses needed to make a zoom lens work. This piece is
now at the Discovery Center of Idaho.
Perception
Ames Room Explainer
....shows the underlying geometry that makes possible the construction of the well-known
Ames Room exhibit. (Built in collaboration with Tom Humphrey)
Land Effect
The eye-brain system has an extraordinary ability to discern the innate color of objects
even if the ambient lighting is varied a great deal. This experiment teases out the strategy
used. In the exhibit, two black and white pictures are superimposed, one illuminated with
green light, one with yellow. The visitor perceives a full color image of the scene. (photo
transparencies supplied by the Polaroid Corporation.)
Peripheral Vision
The exhibit consists simply of a big protractor mounted on a table. It shows that, without
moving our eyes, we have a great panoramic view, more that 180 degrees wide. But of
that view, only a tiny 2 degrees of it is seen in clear detail. That we perceive the visual
world around us in clear detail even though we see it through a kind of fuzzy tunnel vision
was one of the biggest revelations that I have gotten since starting to work at the
Exploratorium.
9. 9
Persistence of Vision
The visitor looks through a three foot long tube that has a narrow slit over the far end.
When the tube is held steady, little can be made out of the scene that the visitor is trying
to look at through the tube. If the tube is swung from side to side, the scene is
immediately discernible.
Touch Sensitivity
A piston mounted in a block can be moved in and out, and made flush with one of the
piston's surfaces. One's ability to detect a small step between the block and the piston
can be measured in increments of .0001 inch.
Navigation
Celestial Navigation
A globe of the earth has been placed beneath a small bright light that represents the Sun.
The exhibit shows how you can, first, determine the Sun's position over the earth if you
know the time (in Greenwich, England, for example) and date. Second, your own distance
from the Sun's position can be determined by measuring the Sun's angle above the
horizon.
Celestial Tools
A sextant, astrolabe, back-staff and cross-staff are displayed. Visitors can try using them
to measure the angle between a small light, representing the sun, and a "horizon" painted
on a distant wall.
Loran Lines
Using string and pulleys, the exhibit demonstrates how loran navigation works. The
exhibit also demonstrates a way in which the hyperbolic curve can be defined.
Orrery
This is a commercially available model of the Solar System that has been strengthened and
mounted to a table top. It augments other exhibits that explain celestial navigation.
Self-Centered Globe
A globe of the earth has been fixed in position so that its axis is aligned with the earth's
axis, and San Francisco's location on the globe is positioned topmost. The globe has been
placed in a sunny area. In this configuration, the Sun's motion and the shadows it can
create are the same on the globe as they are on the earth. The principles of celestial
navigation can be readily demonstrated. (Globe constructed by Ned Kahn.)
10. 10
Miscellaneous
Scanning Electron Microscope
An SEM was donated to the Exploratorium. A great deal of work was done to, first, repair
it, and then to make it suitable for the public to use. They could examine any of six
specimens that we had prepared. Usually the public worked with this exhibit on their
own, but the exhibit worked best when volunteers were there to demonstrate it. The
Exploratorium trained new volunteers regularly. (Project was executed in collaboration
with Stan Axlerod.)
Heliostat
This device was built to supply sunlight for Bob Miller's "Sun Painting". It now, also,
supplies light for "Pin-hole Sun Image" and Bruce Sams' "Solar Signature".
Free Junk
....consists of a large wooden box that the staff fills with things that are too
good/neat/interesting to throw away but are of no real value to the museum. Our visitors
then carry the stuff off.
Not For Free Junk
The Exploratorium keeps a counter-top showcase filled with a variety of things that
actually have some monetary value, and these things are sold to the public.
Valve of Some Sort
(built in collaboration with Larry Shaw)
11. 11
EXHIBITS PROJECTS AT
THE DISCOVERY CENTER OF IDAHO
Slit Lamp Microscope
This is the standard instrument used by ophthalmologists for examining the eye. Ours
was donated by the Lyons Club of Boise. It is an elegant piece of equipment, and can be
used to examine many parts of the eye, but the part that is most fascinating and easiest to
view is the iris. For now, the instrument will only be demonstrated by a trained volunteer.
Doppler Blood Flow Exhibit
Blood flow through the arteries and veins can most effectively monitored by a small ultra-
sonic probe that sends out a continuous wave. Sound reflected from the moving blood is
doppler-shifted, and can then be detected by the same probe. The difference between
the transmitted frequency and the received frequency is detected and can be heard over
a speaker or displayed on an oscilloscope. For the exhibit, we used the standard medical
doppler-detector unit, and connected it to an electrocardiograph monitor, which, for us,
functions as a very nice storage oscilloscope.
Bone Stress,
Bicycle Legs
These two exhibits were copied from plans from the Exploratorium.
Hydraulics Lab
Ratios of the areas of hydraulics pistons is demonstrated. The not-so-obvious workings
of a gear-pump are shown.
Arthroscopy Demonstration.
Visitors can attempt to manipulate surgical manipulators while viewing their work
through an arthroscope.