 |
| "Self Portrait: The Persistence of the Double " approx. 10 x 15 cm. (Array) / 2008 |
 |
| "Self: The Nature and Me" approx. 35 x 50 cm. / Year 2007 Graphite, ink and Rotring s / paper |
Wednesday, June 30, 2010
How To Choose A Cast Color
self-portraits
Tuesday, June 29, 2010
Message For Christening Card
 |
| "In Dialogue the Archetypes: Venus " approx. 20 x 30 cm. / 2007 Graphite s / paper |
 |
| "The Places Reserves: The Tax Haven" approx. 10 x 15 cm. / 2008 Rotring s / tracing paper |
Monday, June 28, 2010
Woolite Regular He Washer
 |
| "After the Speech: From Here to Eternity 25 x 25 cm. (Array) / 2008 Etching |
 |
| "The Nature of Things" 25 x 25 cm. (Array) / 2008 Etching |
Thursday, June 24, 2010
Cheap Wooden Fingerboards Complete
Quincke analemma
To understand the operating principle Quincke tube should be clear that sound is caused by the formation of waves, these waves can represent them graphically as a sine function where the distance between two peaks or two valleys is the wavelength. Although the sine function represents a transverse wave and the sound is a longitudinal wave case, it serves as a model to display the phenomenon of interference.
Elbows per couple fit together with the segments of tube 50 mm in length.
Each ½ "pipe length of 330 mm is placed one of the TEE.
short tubes in the previous assembly tubes are placed ¾ "as shown in the picture. If necessary, use a paste or glue to attach the components.
To end the Quincke tube assembly, put the "U" drops in the tubes of ¾ ".
already have our interferometer Herschel-Quincke. The instrument is with a total length of 750 mm (closed) and width 70 mm between the pipe and tube. These dimensions (length) for the interferometer is chosen so that U Mobile has a displacement of about 20 centimeters, which is greater than the wavelength for a 2,000 Hz tone
As I do not have a tuning fork I will rely on technology. Employ a tone generator program and a small horn (a headset to plug into the PC) to reproduce tones within the Quincke Tube.
The photograph shows one of the horns the headset in place of one of the Quincke tube T to proceed with the experiment. We must be careful that the horn is not the bottom of the TEE for best results.
To minimize "leakage" of sound input by TEE, we will cover the inlet of the TEE with the palm of your hand or a cloth cap. Generating
to 2,000 Hz tone at low volume and placing the ear at the free end about 50 inches apart (this will avoid the saturation of the tone heard by the pilot) we making the mobile tube until the tone decreases in intensity as low as possible, if the volume playback is not very intense, the tone almost disappears. Later still pulling the tube slowly and notice that the tone intensity increases to a maximum. With this first experience we discovered the effect of constructive and destructive interference in the sound.
can perform the same practice with other frequency values \u200b\u200band observe the same behavior, so that we can deduce from the experience that indeed the sound is a wave phenomenon.
repeated the experiment with the exception that you have found the point of minimum sound intensity, measured the length of the tube and brands mobile reference herein. Proceed to slowly remove the tube until moving back to a minimum sound intensity, here we measure the length of the tube or the new distance between the reference marks. The routine can be done with reference to the point of maximum intensity, but my experience showed me that this point is more difficult to establish because the ear tends to saturate preventing the exact location of the point of maximum volume.
The difference between these measurements recorded (gauge length) must be multiplied by two since a change in the length of mobile tube represents the same displacement for each of the branches of the U-mobile, which implies a dual path for sound.
According to the mathematical expression that relates the wavelength at the frequency and velocity, one can calculate or determine the speed of sound.
where v is the velocity of propagation in meters per second "f" the frequency in Hertz and lambda the wavelength in meters.
Because we are doing the experiment with our hearing without assistance of another resource that our ear, we must make a series of measures to find the average value of displacement of the moving tube and minimize measurement errors.
is hoped that the results are not accurate presenting a scatter in the measured values \u200b\u200bbecome even more noticeable in some cases than in others depending on skill and care in running the experiment. But give us an idea of \u200b\u200bthe speed of sound in air and the pleasure of having performed a historic experiment.
did Measurements are displayed in the table below. The temperature of the room where measurements were made hovered between 20 º and 23 º C.
The result I got from the sound velocity of 347 m / s (average value) is excellent considering it was a fairly traditional, the discrepancy with the speed of sound at 20 º C (343 m / s) is 2%.
What we learned from this experience:
• The interferometer or home Quincke tube is fully functional and does not require highly specialized equipment for practices.
• The phenomenon of interference is presented in sound.
• The sound is a wave phenomenon.
• The interferometer is a measurement tool that allows us to measure the wavelength of an audible tone.
• Set the propagation speed of sound in air according to measurements made with the Quincke Tube.
Technologically this experiment suggest us the possibility of "mufflers" tuned to reduce noise levels in many industrial plants and hydroelectric plants, fans, internal combustion engines and more.
An experiment readily achievable, elegant and simple that we can "see" directly the wave nature of sound, feel the effects of constructive and destructive interference in addition to understanding the "mechanics" is a curious experience, teaching and a wide range of possibilities for the creativity of young students from high school.
Quincke TUBE HOME.
AND RESEARCH WORKSHOP
Quincke interferometer, interference with sound waves, speed of sound.
A simple and smart way to demonstrate that sound is a wave phenomenon is through the experiment implemented by Georg H. Quincke.
Quincke tube is a device that allows you to create the phenomenon interference in the sound, thus demonstrating that has wave behavior also that this instrument can measure the wavelength of a pure tone and then either calculate the speed of sound in air temperature prevailing at the time of the experiment. Georg Hermann Quincke
(1834-1924) German physicist who conducted research on the phenomena of capillarity, flocculation, electrophoresis, surface tension. Investigated the optical reflection phenomena on metal surfaces and interference optics, constructing various measuring instruments such as acoustic thermometer, pressure gauge magnetic tube that takes its name.
Although Sir John Herschel (1792-1881) William son of the famous discoverer of the planet Uranus, who presents the experiment and never takes place, being Quincke which runs it. The name of Quincke tube for the interferometer is in her honor although opportunities also known as Herschel-Quincke tube in recognition of both scientists. This entry
recreate Quincke's experiment to witness the phenomenon of acoustic interference in addition to setting the speed of sound depending on us to measure wavelength and frequency tone used. Experience that we use our skills manuals and audio without using sophisticated instruments such as an oscilloscope. For the experiment
first thing we need is the famous Quincke tube and it will build it.
But, What is the Quincke Tube?
Before continuing let's see what is and what is the basis for this interesting tool.
The figure shows schematically the design of the tube which is basically two tubes U joined by a pair of T, one of the "U" is mobile by way of the rod of a trombone.
AND RESEARCH WORKSHOP
Quincke interferometer, interference with sound waves, speed of sound.
A simple and smart way to demonstrate that sound is a wave phenomenon is through the experiment implemented by Georg H. Quincke.
Quincke tube is a device that allows you to create the phenomenon interference in the sound, thus demonstrating that has wave behavior also that this instrument can measure the wavelength of a pure tone and then either calculate the speed of sound in air temperature prevailing at the time of the experiment. Georg Hermann Quincke
(1834-1924) German physicist who conducted research on the phenomena of capillarity, flocculation, electrophoresis, surface tension. Investigated the optical reflection phenomena on metal surfaces and interference optics, constructing various measuring instruments such as acoustic thermometer, pressure gauge magnetic tube that takes its name.
Although Sir John Herschel (1792-1881) William son of the famous discoverer of the planet Uranus, who presents the experiment and never takes place, being Quincke which runs it. The name of Quincke tube for the interferometer is in her honor although opportunities also known as Herschel-Quincke tube in recognition of both scientists. This entry
recreate Quincke's experiment to witness the phenomenon of acoustic interference in addition to setting the speed of sound depending on us to measure wavelength and frequency tone used. Experience that we use our skills manuals and audio without using sophisticated instruments such as an oscilloscope. For the experiment
first thing we need is the famous Quincke tube and it will build it.
But, What is the Quincke Tube?
Before continuing let's see what is and what is the basis for this interesting tool.
The figure shows schematically the design of the tube which is basically two tubes U joined by a pair of T, one of the "U" is mobile by way of the rod of a trombone.
To understand the operating principle Quincke tube should be clear that sound is caused by the formation of waves, these waves can represent them graphically as a sine function where the distance between two peaks or two valleys is the wavelength. Although the sine function represents a transverse wave and the sound is a longitudinal wave case, it serves as a model to display the phenomenon of interference.
waves in phase. Constructive interference.
When two trains of waves are coherent and in phase, the interference that occurs when the two overlap is called "constructive", the end result is another train of waves whose amplitude is the sum of the amplitudes of the two individual waves (see figure above), in the case of sound would increase the sound level of a tone. To the extent that the waves undergo a lag, the resulting final amplitude decreases to a point where both waves are neutralized and the tone disappears. This is the case of interference "destructive."
Waves gap. Destructive interference.
Looking at the graphs that represent the waves, we can deduce that its maximum destructive interference when the gap between trains of waves reaches just half wavelength, ie a valley with a peak overlaps. If the gap occurs at a certain speed will hear a wow created by the succession of ups and downs in the volume of the resulting tone to the extent that the waves are out of phase and phase re-enter. Returning to
Quincke tube, if one of the open ends (one of the union TEE) put a small horn that is emitting a tone, the sound generated must travel the two halves of the tube at the same speed as the travel (the perimeter from the TEE TEE input to output) is equal for both branches in "U" on tee perceive the pitch at full intensity (volume), if we are making the mobile tube gradually notice that the sound intensity decreases to a minimum, this is because sound waves travel through the mobile tube have to make a tour more, so that upon reaching the tee, a branch waves with respect to the other are offset partially or totally cancel each other out. This is the beginning of the interferometer or Quincke tube to show that the sound is a wave phenomenon by means of the interference.
experience to be flashy, it requires that the tone is as pure as possible.
To construct the Quincke Tube version of this blog will need the following materials readily available at hardware stores:
PVC pipe for cold water of 21.8 mm (1 / 2 ") 1,300 mm.
PVC pipe for cold water of 27 mm (3 / 4 ") 400 mm.
TEE PVC tube ½ "02 c / u
90 ° Elbows PVC tube ½" 04 c / u
Sandpaper 100 01 c / u
To assemble Quincke interferometer, the tube of 21.8 mm (1 / 2 ") was cut into eight segments, two 330 mm in length, two segments of 310 mm in length and four segments of 50 mm in length. The tube of 27 mm (3 / 4 ") cut it into two equal pieces of 200 mm as shown in the picture below.
Elbows per couple fit together with the segments of tube 50 mm in length.
Each ½ "pipe length of 330 mm is placed one of the TEE.
between the tubes is 330 mm long with one pair of elbows and each armed TEE were also placed a segment of pipe 50 mm, see picture siguiernte.
short tubes in the previous assembly tubes are placed ¾ "as shown in the picture. If necessary, use a paste or glue to attach the components.
is required the tubes from ½ "missing on the device by placing the tubes slide into ¾" as does the trombone rod to do is sand the outside diameter (carefully so that the game minimum) of the tubes from ½ "through which, when introduced into tubes ¾" glide smoothly, this is achieved, the tube ½ "sanded mate with the remaining 90 ° elbows as shown in the picture below.
To end the Quincke tube assembly, put the "U" drops in the tubes of ¾ ".
already have our interferometer Herschel-Quincke. The instrument is with a total length of 750 mm (closed) and width 70 mm between the pipe and tube. These dimensions (length) for the interferometer is chosen so that U Mobile has a displacement of about 20 centimeters, which is greater than the wavelength for a 2,000 Hz tone
As I do not have a tuning fork I will rely on technology. Employ a tone generator program and a small horn (a headset to plug into the PC) to reproduce tones within the Quincke Tube.
The photograph shows one of the horns the headset in place of one of the Quincke tube T to proceed with the experiment. We must be careful that the horn is not the bottom of the TEE for best results.
To minimize "leakage" of sound input by TEE, we will cover the inlet of the TEE with the palm of your hand or a cloth cap. Generating
to 2,000 Hz tone at low volume and placing the ear at the free end about 50 inches apart (this will avoid the saturation of the tone heard by the pilot) we making the mobile tube until the tone decreases in intensity as low as possible, if the volume playback is not very intense, the tone almost disappears. Later still pulling the tube slowly and notice that the tone intensity increases to a maximum. With this first experience we discovered the effect of constructive and destructive interference in the sound.
can perform the same practice with other frequency values \u200b\u200band observe the same behavior, so that we can deduce from the experience that indeed the sound is a wave phenomenon.
repeated the experiment with the exception that you have found the point of minimum sound intensity, measured the length of the tube and brands mobile reference herein. Proceed to slowly remove the tube until moving back to a minimum sound intensity, here we measure the length of the tube or the new distance between the reference marks. The routine can be done with reference to the point of maximum intensity, but my experience showed me that this point is more difficult to establish because the ear tends to saturate preventing the exact location of the point of maximum volume.
The difference between these measurements recorded (gauge length) must be multiplied by two since a change in the length of mobile tube represents the same displacement for each of the branches of the U-mobile, which implies a dual path for sound.
According to the mathematical expression that relates the wavelength at the frequency and velocity, one can calculate or determine the speed of sound.
where v is the velocity of propagation in meters per second "f" the frequency in Hertz and lambda the wavelength in meters.
Because we are doing the experiment with our hearing without assistance of another resource that our ear, we must make a series of measures to find the average value of displacement of the moving tube and minimize measurement errors.
is hoped that the results are not accurate presenting a scatter in the measured values \u200b\u200bbecome even more noticeable in some cases than in others depending on skill and care in running the experiment. But give us an idea of \u200b\u200bthe speed of sound in air and the pleasure of having performed a historic experiment.
did Measurements are displayed in the table below. The temperature of the room where measurements were made hovered between 20 º and 23 º C.
"Lmin is the length between reference marks for the first minimum loudness found," Lmax is the length recorded by extending the mobile tube to the next minimum intensity, the difference between the two values \u200b\u200bis the wavelength corresponding frequency in Hertz.
The result I got from the sound velocity of 347 m / s (average value) is excellent considering it was a fairly traditional, the discrepancy with the speed of sound at 20 º C (343 m / s) is 2%.
What we learned from this experience:
• The interferometer or home Quincke tube is fully functional and does not require highly specialized equipment for practices.
• The phenomenon of interference is presented in sound.
• The sound is a wave phenomenon.
• The interferometer is a measurement tool that allows us to measure the wavelength of an audible tone.
• Set the propagation speed of sound in air according to measurements made with the Quincke Tube.
Technologically this experiment suggest us the possibility of "mufflers" tuned to reduce noise levels in many industrial plants and hydroelectric plants, fans, internal combustion engines and more.
An experiment readily achievable, elegant and simple that we can "see" directly the wave nature of sound, feel the effects of constructive and destructive interference in addition to understanding the "mechanics" is a curious experience, teaching and a wide range of possibilities for the creativity of young students from high school.
Subscribe to:
Posts (Atom)