Cell Phones

Cell Phones

1. Chemistry

   • Touch screen
     • Indium Tin Oxide
       • Is used in a transparent film in the screen
         • This allows the screen to function as a touch screen
     • Aluminosilicate glass
       • Mixture of aluminium oxide and silicon dioxide
         • Placed in a hot bath molted salt
           • Producing a layer of pressure on the glass, an incresing its strength
             • Resistance to mechanical damage
     • Several of other rare earth elements are also present in very small quantities
     • Liquid crystal display
       • Scratch resistance glass
   • Battery
     • Lithium Ion
       • Uses lithium cobalt oxide as the positive electrode and graphite as the negative in the battery
     • Other phones
       • other metals
         • Aluminum battery case
   • Inside mobile phone
     • The chip (processor) in the phone
       • Made from pure silicon
         • exposed to oxygen and heat
           • In order to produce film of silicon dioxide on it surface
     • Micro electrical components and wiring in the phone are composed
       • copper, gold and silver
         • Tantalum
           • Main component of micro-capacitrors
   • /
     • Neodymium-iron-born
       • Vibration
     • Nickel
   • climate change is related to chemistry because the technology produced has used composition, structure, properties and change of matter.

2. Physics

   • Microphone,speaker
     • Dysprosium and Praseodymium
     • Tin and lead
   • Radio-Frequency Electromagnetic waves
     • sends Electric signals
       • send and receive the sounds
     • If this stop its does not work
     • Transmitted to a base tower
       • so the radio waved transmit can travel over
         • they connect to towers and cover a single area, or cell, of signal reach, and many towers are spread across the country to provide full cell coverage.
       • microphone in the handset converts the up-and-down sounds of your voice into a corresponding up-and-down pattern of electrical signals.
         • A microchip inside the phone turns these signals into numbers
           • Numbers are packed up into a radio wave are beamed out from antenna or wirelessly
     • This is related to biology because of the electromagnetic radiation caused in health risks by cell phones- Electromagnetic was spectrum was taught in class
     • physics is related to climate change by The electromagnetic waves scattered through the atmosphere is related to climate change
   • spread across the country to provide full cell coverage
   • How cell phone work
     • Amplifier
       • Adds energy to the radio wave
     • Inductor oscillator
     • Modulator
       • Carrier wave
         • Voice signals
           • Composite signals
     • Transmitter
       • Antenna
       • Reciver
   • The lens of the eye is similar to one in glasses or cameras.
     • The different parts of the eye has different refractive indexes, and this is what bends the rays to form an image.
       • The image passes through several layers of the eye, but happens in a way very similar to that of a convex lens.
       • Eye is is related to physics because of the anatomy of lens. which we also learned in class
   • chemistry is related to physics because the metals produced use electromagnetic to make the actual phone to work. for ex. microphones and speaker carry voltage and waves that pass and transfer sound, which is part of radio frequency- Most of these com ponds were used and talked about throughout the unit, while using / making the green chemistry project and class discussion

3. Biology

   • cell phone can heat a large group of cells.
   • Cancer Risk
     • emit radiofrequency energy, a form of non-ionizing electromagnetic radiation
       • Absorbed by tissues closest where the phone is held
       • amount of radiofrequency energy a cell phone user is exposed to depends on the technology of the phone
         • The distance between the phone's antenna and the user
       • biological effect of radiofrequency energy is heating
     • Reduce cancer risk
       • cell phones for shorter conversations or for times when a landline phone is not available.
       • Use a hands-free device, which places more distance between the phone and the head of the user.
   • Effects
     • Short term
       • Tissue heating is the principal mechanism of interaction between radiofrequency energy and the human body
         • most of the energy is absorbed by the skin and other superficial tissues
           • resulting in negligible temperature rise in the brain or any other organs of the body
     • Long term
       • Epidemiological research examining
         • radiofrequency exposure has mostly looked for an association between brain tumours and mobile phone use.
     • Could cause chronic pain
   • Eyes
     • Tiny fonts in bright screens can make you squint and strain your eyes,
       • This can lead toan eye condition which is computer vision syndrom
         • Symptoms
           • lead to dry eye
           • Difficult focusing
           • Headaches
           • Blurred visions
           • Redness in eyes

4. Climate Change

   • Making use of technology
     • by recording and transmit sound, images, location, and motion data.
       • By combining these data with Web services to aggregate and interpret the assembled information, mobile phones can be powerful proxies for sensors
     • mobile phones are now powerful multi-media devices with cameras and GPS capabilities in addition to voice and Internet access, mobile phones can transform scientific data collection without the need for the high bandwidth, rich sensor capabilities, or local processing infrastructure that had previously been barriers to collection of data in rural, developing regions.
   • Information and Communication Technologies (ICTs), such as satellites, mobile phones or the Internet, play a key role in addressing the major challenges related with climate change and sustainable development.
     • Global warming
       • charging your phone uses more electricity
         • electricity is generated by the energy created when you burn coal. This burning releases huge amounts of carbon dioxide, the major greenhouse gas that causes global warming.
   • microwave radio frequencies are scattered through our atmosphere at an accelerated rate.
     • The earth is rotating electromagnetic field containing dielectric material
       • Sending oscillating microwave radio frequencies through an electromagnetic field into dielectric material
         • Creates radio frequency heating