Showing posts with label hobby projects. Show all posts
Showing posts with label hobby projects. Show all posts
Monday, 25 March 2013
Saturday, 12 January 2013
Steel Wool & Vinegar Reaction
Steel Wool & Vinegar Reaction
Soak steel wool in vinegar and watch what happens as the iron in the steel begins to react with the oxygen around it. This fun science experiment for kids is great for learning about chemical reactions.
Soak steel wool in vinegar and watch what happens as the iron in the steel begins to react with the oxygen around it. This fun science experiment for kids is great for learning about chemical reactions.
What you'll need:
Instructions:
What's happening?
The temperature inside the beaker should gradually rise, you might even notice the beaker getting foggy. When you soak the steel wool in vinegar it removes the protective coating of the steel wool and allows the iron in the steel to rust. Rusting (or oxidation) is a chemical reaction between iron and oxygen, this chemical reaction creates heat energy which increases the temperature inside the beaker. This experiment is an example of an exothermic reaction, a chemical reaction that releases energy in the form of heat.
|  |
Microscopic Creatures in Water
Microscopic Creatures in Water
Water can be home to a lot of interesting creatures and microorganisms, especially if it's dirty water found in ponds or near plants. Take some samples, view them under a microscope and see what you can find. How clean is the water from your tap compared to the water found in a pond? Experiment and see what kind of microscopic creatures you can find!
Water can be home to a lot of interesting creatures and microorganisms, especially if it's dirty water found in ponds or near plants. Take some samples, view them under a microscope and see what you can find. How clean is the water from your tap compared to the water found in a pond? Experiment and see what kind of microscopic creatures you can find!
What you'll need:
Instructions:
What are you looking at?
Some of the creatures and microorganisms you might be able to see include:
|  |
Friday, 28 December 2012
Home-made Stethoscope
Home-made Stethoscope
Purpose
To demonstrate how sound waves can travel through enclosed spaces and become aplified by creating a home-made stethoscope.
Additional information
The stethoscope was invented in 1816 by French physician and inventor René-Théophile-Hyacinthe Laennec. The idea came to Laennec when he witnessed children playing with a long piece of wood that transmitted the sound of pins scratching the surface. After making the observation, the next day he rolled up a piece of paper into the shape of a funnel. He then used it to listen to the chests of his patients. Discovering the funnel amplified the sounds from his patients chests, Laennec (who had a background in carpentry) built a 25cm by 2.5cm hollowed wooden cylinder. This cylinder replaced the rolled up paper tube as a device to listen to his patients chest. He later modified this device with detachable parts. He notated the various sounds he heard with his primitive stethoscope and related them to anatomical findings at his patients autopsies. He published his findings in 1819 and the stethoscope, derived from the Greek word "stethos" (meaning chest), was born. As he neared death Laennec often referred to the stethoscope as "the cylinder" and bequeathed his own stethoscope to his nephew, accurately referring to it as the "the greatest legacy" of his life.
Sponsored Links
Required materials
- 2 Funnels
- Old garden hose (it will need to be cut-up)
- Scissors
- Modeling clay
- Pen or pencil
- Journal
Estimated Experiment Time
About 15 minutes
Step-By-Step Procedure
- 1. Use your scissors to cut a piece of garden hose approximately 16 inches in length. Make sure to cut from the middle of the house as you'll need both ends to be even (don't use the end that connects to outdoor faucets).
- 2. Place one of the funnels onto the end of the garden hose. If it doesn't fit tightly, use some modeling clay to secure it.
- 3. Repeat step 2 with the other funnel on the other end of the garden hose.
- 4. Place one end of the funnel over your heart and the other end over your ear. What do you hear? Count your heartbeat rate for 30 seconds and note them in your journal.
- 5. Do some jumping jacks, run around, exert a lot of energy for about 1 minute.
- 6. Use your stethoscope again, with one end over your heart and one end to your ear. Now what do you hear? Again count your heart beat rate for 30 seconds and note them in your journal.
Note
If you're having trouble cutting the garden hose with a scissor, you may need to use a sharp knife or razor. As always, make sure you have the help of an adult when cutting objects!
Observation
Can you think of other materials you could use to create a home-made stethoscope? What other purposes, beyond listening to your heartbeat, can you find for the stethoscope?
Result
Stethoscopes can measure the rate of your heart and assist in determining how many times your heart beats per minute. The stethoscope works on the simple principle of acting as a sound amplifier that carries the sound along the hose to your ears.
Vibrating Coin
Vibrating Coin
Purpose
To demonstrate the expansion of air when heated.
Additional information
The temperature of a gas is directly proportional to the speed with which its molecules move. Increasing the temperature of a gas results in an increase of the average speed (and therefore the kinetic energy) of its molecules. This in turn causes the molecules to ‘spread out’ by virtue of a phenomenon known as thermal expansion.
Sponsored Links
Required materials
- Coin
- Bottle
- Refrigerator
- Water
Estimated Experiment Time
Approximately 15 to 20 minutes
Step-By-Step Procedure
- 1. Place an empty bottle in a refrigerator to cool
- 2. Place the cooled bottle outside
- 3. Dip your finger in water and place a few drops around mouth of the bottle and the edge of the coin
- 4. Place a coin on the mouth of the bottle
- 5. Place both your hands around the bottle; hold firmly
- 6. Remove your hands after a while
Note
- Use a bottle with a mouth narrow enough to be closed completely with a coin.
- Applying water on the rim of the bottle mouth and the coin’s edge will help seal the bottle.
Observation
In approximately fifteen seconds from covering the bottle with your hands, the coin will start to vibrate up and down. When you do remove your hands after a short while, the coin continues to vibrate.
Result
As soon as the bottle is taken out of the refrigerator the temperature of the gas inside the bottle begins to rise; encasing the bottle with your hands increases the temperature further. When the bottle is heated, the air molecules inside it start moving faster and these molecules collide with the coin with more energy. This results in increased pressure which in turn is caused by the expanding air that escapes though the rim of the coin and makes it vibrate.
Measuring Water pH
Water pH
Purpose
To determine the pH level of both city water and well water to determine which is more basic and which is more acidic.
Additional information
Many people report that well water is better for you than city water. They also report that it tastes better, as well water does not undergo chemical treatment when city water does.
Sponsored Links
Required materials
- 2 test tubes or other small container for water collection
- 20 pH strips with guide
- Journal or logbook
- Source of city water
- Source of well water
- Test tube labels or labeling marker
Estimated Experiment Time
This experiment will most likely take several hours.
Step-By-Step Procedure
- 1. Label one of the test tubes “City Water” and make sure you are only using this test tube for that type of water.
- 2. Collect one sample of water and use the pH strip to test its pH level. Record your findings.
- 3. Repeat step two with nine more samples of city water, for a total of ten city water samples.
- 4. Label the second test tube “Well Water” and make sure you are only using this test tube for that type of water.
- 5. Repeat steps two and three for the well water.
Note
The pH strips can easily be found at your local home and garden supply store. You can use the same test strips that are used to test the pH of pools or ponds, as long as they are pH testing strips and come with a color guide that allows you to accurately determine the pH level of the water from the used strips.
Observation
You can tape the test strips in your journal as part of your observation or use them as part of your science fair project display. You can also create a graph of your findings to easily display the pH information of both the city and well water.
Result
The results of the experiment depend on the information obtained from the pH strips for both types of water. Did one type of water exhibit a higher or lower pH level than the other? If so, how much of a difference was there? Were the pH levels about the same? Based on the information obtained during your experiment, which type of water do you think is the best for drinking?
Measuring Air Pollution
Measuring Air Pollution
Purpose
To determine the amount of foreign particles in the air in a specific area.
Additional information
Breathing air is vital to our existence, but have you ever thought you might not be breathing purely clean air? This simple experiment will give you an idea of how “dirty” your air is.
Required materials
- White posterboard
- Scissors
- Vaseline
- String
- Hole punch
- Magnifying glass
- Permanent black marker
- Journal or notebook
Estimated Experiment Time
About a week.
Step-By-Step Procedure
- 1. Find an area in which you can hang several cut out pieces of the posterboard. You can do this in your home if you’d like to find out how clean the air in your home is, or you can hang the cut out pieces of posterboard outside in your yard or another area.
- 2. Cut the posterboard into several squares.
- 3. Draw a square with the marker on each cut out piece of posterboard, a little smaller than the square itself.
- 4. Punch a hole in the top of each piece of posterboard and tie pieces of string in the holes so you can hang the cut outs in various areas.
- 5. Smear a thin layer of Vaseline inside the drawn square on each cut out and hang them in different places within the area you’ve chosen. Record the areas you’ve hung each cut out in your notebook.
- 6. In about a week, collect your squares.
Observation
With the magnifying glass, count how many particles you can see stuck to the Vaseline in each square. Record the number of particles, as well as the location of each cut out in your journal.
Result
You will most likely find some amount of particles stuck to the cut outs. Are there a lot of particles or just a few? How do you think the area you’ve chosen to perform the experiment in has affected your results? What do you think would happen if you performed this experiment in a heavily polluted area, such as a big city or an area with known air pollution? Do you think you would find more particles stuck to the cut outs? How do you think the particles in the air affects the air quality and our ability to breathe well?
Galileo's Experiment
Purpose
To demonstrate Galileo's falling objects experiment that states "What goes up, must come down". After this experiment you'll be able answer the question "Do larger objects fall faster than lighter ones under the same conditions?"
Additional information
Born in 1564, Galileo Galilei was an Italian physicist, astronomer, philosopher, and mathematician. Around the year 1589 Galileo set out to prove that two objects of varying size and weight would hit the ground at the same time when dropped from great heights. This was contrary to popular belief and the teachings of Aristotle, who theorized that objects of greater weight fall faster than those of lighter weight. To prove his theory, it's said that Gelileo dropped a 10 pound ball and a 1 pound ball from the top of the Leaning Tower of Pisa. A large crowd witnesses Galileo prove his theory and disprove Aristotle’s when the balls hit the ground at the same time.
Take a moment to visit our table of Periodic Elements page where you can get an in-depth view of all the elements, complete with the industry first side-by-side element comparisons!
Step-By-Step Procedure
- 1. If using a video camera, set the camera up on a tripod or solid surface. Make sure to position the camera so that it can capture the entire procedure (from the point the balls drop to where they hit the ground).
- 2. Climb the ladder and prepare to drop both balls at the same time. It's best to have someone spot you and help you balance while on the ladder.
- 3. Once situated safely on the ladder, place a ball in each hand. Hold both hands out at equal length and distance.
- 4. Count to 3 and release the balls at the same exact time.
- 5. After the balls hit the ground, record the results in your notepad.
- 6. To verify your notes, review the optional video recording.
- 7. Repeat the experiment several times, preferably a minimum of 10 times. Record the results separately for each iteration of the experiment.
Observation
When you dropped the balls from the ladder, which ball hit the ground first... the heavy ball or the light ball? If one hit before the other, how many times did this occur? Galileo's experiment is contingent on objects being dropped under the same conditions. With any experiment, there is a degree of human error that can result in skewed results. We conduct the experiment several times to ensure our results are accurate and to take into account variances (such as not releasing the balls at identical times). The video recording is key to ensure our testing conditions were identical and to verify results.
Result
When dropped, both the heavier ball and the lighter ball should hit the ground at the same exact time, proving Galileo’s theory that objects, in direct proportion to weight, fall at the same rate.
Sponsored Links
Take a moment to visit our table of Periodic Elements page where you can get an in-depth view of all the elements, complete with the industry first side-by-side element comparisons!
ieee papers for project(vlsi & es)
1 A low-power low-noise CMOS analog front-end
IC for portable brain-heart Monitoring applications
Abstract
In this paper, a low power and low noise eight-channel analog front-end (AFE) IC for portable brain-heart monitoring applications is presented. The developed IC features a fully integrated eight-channel design which includes one channel for diffuse optical tomography (DOT), three channels for electrocardiography (ECG), and four channels for electroencephalography (EEG). In order to achieve the targets of lower power, lower noise, and more efficient area utilization, a new programmable readout channel is invented which is composed of a chopper-stabilized differential difference amplifier (CHDDA), an adjustable gain amplifier, and an adjustable low pass filter (LPF). Furthermore, a 10-bit successive approximation register analog-to-digital converter (SAR-ADC) is employed in conjunction with an analog multiplexer to select a particular biosignal for analog-to-digital conversion. The proposed IC has been fabricated in the TSMC 0.18 um CMOS technology and simulated using HSPICE under a 1.8-V supply voltage and an operating frequency of 512 Hz. The power supply rejection ratio (PSRR) +/- of the CHDDA is 113/105 dB. The power consumption of the programmable readout channel and the SAR-ADC is about 71.159 μW and 8.27 μW, respectively. The total power consumption of the full AFE chip is about 506.38 μW and the chip area is about 1733 × 1733 um2.
ieee papers for project(vlsi & es)
A
Novel Design and Simulation of a Compact and Ultra Fast CNTFET Multi-valued
Inverter Using HSPICE
Abstract
This paper presents a novel design of a
compact multi-valued inverter circuit using Carbon Nanotube Field effect
Transistor (CNTFET). All simulations are done by using HSPICE
model of CNTFET. The novelty of this paper is by using only one circuit all
multi-valued output can be achieved than using three different CNTFET circuits
or complex band-gap reference circuits to produce each reference voltage for
precise output in case of CMOS implementation which are previously done. Also
the same design implementation using MOSFETs with different threshold mask
would increase higher process cost. It is widely considered that CNTFET
possesses high fabrication feasibility and superior device performance than
MOSFET. The extensive simulated results and performance bench-marking of the proposed
design also show a significant reduction in power
delay product (PDP) which aids over 50% faster speed than typical multi-valued
inverter. Hence with this uniquely new design it is possible to accomplish
simplicity, energy efficiency and of course reducing the chip area in modern
ultra low power VLSI circuits.
Paper Link : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=6205527&contentType=Conference+Publications&ranges%3D2011_2012_p_Publication_Year%26matchBoolean%3Dtrue%26searchField%3DSearch_All%26queryText%3D%28%28%28VLSI%29+AND+Low+power%29+AND+hspice%29
Abstract
This paper presents a novel design of a
compact multi-valued inverter circuit using Carbon Nanotube Field effect
Transistor (CNTFET). All simulations are done by using HSPICE
model of CNTFET. The novelty of this paper is by using only one circuit all
multi-valued output can be achieved than using three different CNTFET circuits
or complex band-gap reference circuits to produce each reference voltage for
precise output in case of CMOS implementation which are previously done. Also
the same design implementation using MOSFETs with different threshold mask
would increase higher process cost. It is widely considered that CNTFET
possesses high fabrication feasibility and superior device performance than
MOSFET. The extensive simulated results and performance bench-marking of the proposed
design also show a significant reduction in power
delay product (PDP) which aids over 50% faster speed than typical multi-valued
inverter. Hence with this uniquely new design it is possible to accomplish
simplicity, energy efficiency and of course reducing the chip area in modern
ultra low power VLSI circuits.Paper Link : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=6205527&contentType=Conference+Publications&ranges%3D2011_2012_p_Publication_Year%26matchBoolean%3Dtrue%26searchField%3DSearch_All%26queryText%3D%28%28%28VLSI%29+AND+Low+power%29+AND+hspice%29
Thursday, 27 December 2012
Mobile incoming call indicator
Description.
This circuit can be used to escape from the nuisance of mobile phone rings when you are at home. This circuit will give a visual indication if placed near a mobile phone even if the ringer is deactivated.
When a call is coming to the mobile phone, the transmitter inside it becomes activated. The frequency of the transmitter is around 900MHz.The coil L1 picks up these oscillations by induction and feds it to the base of Q1. This makes the transistor Q1 activated.Since the Collector of Q1 is connected to the pin 2 of IC1 (NE555) , the IC1 is triggered to make the LED connected at its output pin (pin 3) to blink. The blinking of the LED is the indication of incoming call.
Notes.
- The coil L1 can be made by making 150 turns of 36 SWG enameled copper wire on a 5mm dia plastic former.Or you can purchase a 10 uH coil from shop if available.
- The circuit can be powered from a 6V battery.
- Assemble the circuit on a good quality PCB.
- C1 & C3 are to be polyester capacitors.
- The electrolytic capacitor C2 must be rated 10V.
Plant moisture level monitor
Description.
Here is a simple circuit that will give a visual indication when the soil water level inside your flower pot goes low below a certain limit.
The U1C and associated components are wired as an oscillator producing a 2KHz square wave. This square wave is given to one gate input of U1D via a variable potential divider former by R1 and R2.When the resistance across the probes A and B are low that is when soil moisture level is high, the C2 will divert the square wave to ground. The output of U1D will be high. The U1 A inverts this high state to low and so the IC U1B is blocked from producing oscillations. The LED will remain OFF. When there is no moisture across the probes, the C2 cannot bypass the 2KHz signal to the ground and it appears at the gate input of U1D.The output of U1D goes low, and it is inverted to high by U1A.The oscillator wired around U1B is activated and it starts oscillating. These oscillations are amplified by Q1 to drive the LED and LED starts pulsating as an indication of low moisture. Since square wave is used there won’t be any oxidation on the probes. The resistor R7 limits the current through LED and ensures a longer battery life.
Notes.
- Power the circuit from a 3V battery.
- Two metal wires 10 cm long and 5cm apart driven into the soil will do the job for probes.
- The probes are to be connected at the terminals A and B shown in circuit.
- Capacitors C1 and C2 must be polyester type.
- The IC U1 is a quad two input Schmitt NAND IC 4093.
- The sensitivity can be adjusted by varying the preset R2.
- Mount the IC on a holder.
Subscribe to:
Posts (Atom)
