Vibration Isolation Platform

How to minimise down &side transmission of vibration and noise from a subwoofer in a Victorian terraced house

The home cinema room is on the middle floor and has a word floor.
My front Mission floorstander speakers cIaim to go down to 38hz.
Should I :
1) insist on front firing , not downwards firing , models?
2) avoid performancebelow 25 hz ?
3) rely on a wooden?/stone? isolation platform, supported on Sorbothane?
4) Give up the idea?

The whole point of a subwoofer, is to give that chest thumping, sofa shaking effect during the big bangs in movies.

If sofa shaking is out, so is a subwoofer, I'm afraid.

I've just upgraded my sub - I used to have a Kef PSW-2000. It went down to 33Hz and had a 150 watt amp. Our place has a solid concrete floor - the sofa still shook...

SHOCK/VIBRATION ISOLATION PLATE $99.99 SHOCK/VIBRATION ISOLATION PLATE

Vibration $81.25 Vibration. Balancing machine, Base isolation, Cushioning, Damping, Dunkerleys Method, Earthquake engineering, Fast Fourier transform, Mechanical resonance, Mode shape, Noise, vibration, and harshness, Shock (mechanics) Author: Miller, Frederic P./ Vandome, Agnes F./ McBrewster, John Binding Type: Paperback Number of Pages: 88 Publication Date: 2009/10/26 Language: English Dimensions: 5.98 x 9.01 x 0.21 inches

Sefour Isolation Platform V2 Black $146.99 Selfour's Isolation Platform V2 is ideal for DJ's recording mix sessions in the club or studio as it's made to separate all equipment from the floor, thus reducing bass resonance. It is able to do this thanks to 4 specially designed ISOP feet that hold up the sonic reduction steel platform. This takes away the vibrations and eliminates movement during even the hardest hitting sets. The isolation platform is made of thick steel and finished in gloss black. Measures 53-1/8"W x 14-1/2"D.

Isolation $4.99 Isolation

Da-Lite CM-VIP Vibration Isolation Ceiling Plate $90.99 6838 Da-Lite Ceiling Universal Projector Mount CM-VIP CM-VIP Vibration Isolation Ceiling Plate Da-Lite Da-Lite Screen Company Mounting Adapter Projector www.da-lite.com

Auralex GRAMMA Amplifier and Monitor Isolation Platform $54.99 The GRAMMA is an incredibly effective device that's used to float an amp or loudspeaker and yields nearly total acoustic isolation, resulting in a purity of tone that has to be heard to be believed!

Mechanics of Rubber Bearings for Seismic and Vibration Isolation $118.31 No Synopsis Available

Shure A55M Isolation Mount $25 The Shure A55M Shock Stopper isolation mount reduces transmission of mechanical noise and vibration to your mic by more than 20dB. Compatible with Shure models SM57, SM58, Beta 58A, or any Shure microphone with a tapered handle.

Shure A55m Isolation Mount $25 The Shure A55M Shock Stopper isolation mount reduces transmission of mechanical noise and vibration to your mic by more than 20dB. Compatible with Shure models SM57, SM58, Beta 58A, or any Shure microphone with a tapered handle.

Chief Manufacturing CMA-347 Projector Mounting Vibration Isolation. Each $324.95 Manufacturer: Chief Manufacturing. Each. The CMA-347 is the only true vibration-dampening accessory on the market today. It is a unique design that soaks up vibration above the mount connection point. Can be used with any 1 1/2" NPT extension columns and

BH Fitness Advanced Body Platform Vibration Machine $1999 BH Fitness - Core Training - BH ABP - The Advanced Body Platform Vibration Machine by BH Fitness represents the the latest in home fitness technology. This amazing machine uses vibration to stimulate muscles, which in turn burns fat and boosts metabolism. Critics have awarded this model Head of Class and you'll soon reap the health benefits and the value this model offers in advanced technology. Decades of research on vibration technology benefits are well documented for providing a full-body workout in just minutes a day! Why spend hours at the local gym when you can improve muscle tone, strength, stimulate circulation, soothe sore muscles and much, much more in the comfort of your home! Whether you're athlete in training or simply trying to tone, Advanced Body Platform Vibration Machine is your solution! Vibration Energy Output : Low Amplitude producing Peak to Peak Wave Displacement of 1 to 2 mm High Amplitude (H) producing 3 to 4 mm Displacement Frequency : 30, 35, 40 and 45 Hertz Time Selections : 30, 60, 90 and 300 Seconds Power Supply : 110V Powers (2) 150 Watt AC Motors Home Warranty : 10 Year Frame, 2 Year Parts, 1 Year Labor Multi Position Hypo Allergenic Central Grip Handlebar Headrest for Seated Exercises Vibration Plate Fitted with 10 mm Thick Yoga Mat Includes Exercise Belts and Training Guides Wheels for Easy Transportation Fibreglass & Steel Construction for Stability Note: Please consult your physician before use.

Icon Health and Fitness PFVB09988 Activator V3 Vibration Platform $382.73 This vibration platform features a strong motor and shock system to deliver the optimal amount of vibration and displacement needed for fast results. Ergonomically designed for comfort the platform offers challenging exercise for both beginners and experienced athletes. The platform is also compatible with iFit workout cards that plug directly into the easytoread console and automatically adjust the platform s operation. Offers selectable vibration intensities causing muscles to contract at different rates Compatible with iFit workout cards that offer predetermined routines featuring the voice of a personal trainer Ergonomic design ensures comfort as you exercise Easy to read and understand for simple operation. Voltage: 120V. Batteries Required (Included or Not): None. Display: LCD. Space Saver: No. Adjustable: No. Number of Vibration Levels: 3. Assembly Required: Yes. Material(s): Steel Frame Plastic Plate. Includes: Vibration Platform Workout DVD. Dimensions: 35 L x 28 3/10 W x 18 H.

Auralex Great Gramma Amplifier and Monitor Isolation Platform $72.24 The Auralex Great GRAMMA (Gig and Recording, Amp and Monitor Modulation Attenuator) is an incredibly effective patented device that's used to float an amp or loudspeaker. Built on the success of original GRAMMA, the Great GRAMMA is almost 30% bigger to float large speaker cabinets. Great GRAMMA yields nearly total acoustic isolation, resulting in a purity of tone that has to be heard to be believed! Now 4x12s, 15-inch or 18-inch speaker cabinets will benefit from the awesome Great GRAMMA. Only Great GRAMMA can handle the big rigs! Acoustic Treatment Equals World-Class Sound! Auralex Acoustics is the industry leader in acoustical treatment products. By implementing the proper acoustical treatments, Auralex can make even the worst-sounding room good enough to yield world-class sound. Your recordings will yield the real sound of an instrument, voice or loudspeaker to come through. AMS has teamed up with the engineers at Auralex Acoustics to help you plan the fine tuning of your room – for free! Click here for the form! Let the experts at Auralex help you achieve world-class acoustics in any room. Step by step instructions for the Personalized Room Analysis form. Download the form. Open it and print it out. Complete the form Mail, Fax or Email to the form to the provided contact on the form Your Auralex Consultant will email (preferred) or fax suggestions to you. Decide which products you need and contact AMS to place your order! Customer Quotes The GRAMMA is truly amazing! I used it with one of my Fender Black Face Twin Reverbs and it gave my amp a whole BRAND new sound! For the first time my amp sounded ALIVE with a lot of sparkle and punch! I am a tone freak and I am hearing GREAT tones for the first time coming out of my Twin Reverb, it's a total night and day difference! I can finally feel and hear the amp breathe the way that it was intended too. I am going to use the GRAMMAs on all my amps from now on (In the studio and LIVE on the stage). My Marshalls and Fender amps are finally going to sound GREAT! I am in TONE heaven! Very Happy! Eric Mantel - www.ericmantel.com Auralex products are unchallenged both live and in the studio. I love Auralex’s new GRAMMA. On stage it really smooths all my guitar tones. In clubs, theaters and even outdoors, the GRAMMA really makes a huge difference…The production crew of Tower of Power was so impressed, they started using them underneath the horn section monitors, the keyboardist’s LESLIE speaker and several drum mics…FANTASTIC results all the way around. Jeff Tamelier - Guitarist, Tower of Power “Having placed the brilliant Velodyne CHT-10 atop this cool looking device (the GRAMMA), I started my listening tests. POW!!!!! Suddenly, the lower octaves including mid bass took on a clarity and roundness I've not heard before. Tight bass took on a new meaning. I really feel like I'm onto something here. They are simply incredible.” Eric Salih - Cinema Experience (owner) T

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Telescope Vibration Isolation Platform

Charectization Of Carbon Nanotubes Based On Spectroscopic Techniques & Their Optical Properties

 

Charectization of carbon nanotubes based on spectroscopic techniques & their optical properties.

The optical properties of carbon nanotubes refers to the absorption, photoluminescence, and Raman spectroscopy of carbon nanotubes. Because spectroscopic techniques  allow quick and reliable characterization of "nanotube quality" in terms of non-tubular carbon content, structure (chirality) of the produced nanotubes, and structural defects. Those features determine nearly any other properties such as optical, mechanical, and electrical properties.

Carbon nanotubes are unique "one dimensional systems" which can be achieved by rolling graphene sheet.This rolling can be done at different angles and curvatures resulting in different nanotube properties. The diameter canvaries in the range 0.4–40 nm, but the length nanotube is about ~10,000 times reaching 4 cm. Thus the nanotube  have aspect ratio, (i.e  the length-to-diameter ratio) as high as 28,000,000:1,which is unequalled by any other material.As a result, all the properties of the carbon nanotubes relative to those of conventional semiconductors are extremely anisotropic and tunable.

 The tunability of properties is most useful in optics and photonics.

Carbon nanotubes are of three types

1.zig-zag

2.armchair

3.chiral

Following are the optical methods of charecterization ogf CNTs:

1. Optical absorption

Optical absorption in carbon nanotubes differs from absorption in conventional 3D materials by presence of sharp peaks (1D nanotubes) instead of an absorption threshold followed by an absorption increase (most 3D solids). Absorption in nanotubes originates from electronic transitions from the v2 to c2 (energy E22) or v1 to c1 (E11) levels, etc. The transitions are relatively sharp and can be used to identify nanotube types.

Interactions between nanotubes, such as bundling, broaden optical lines. While bundling strongly affects photoluminescence, it has much weaker effect on optical absorption and Raman scattering.

Optical absorption is routinely used to justify the  quality of the carbon nanotube powders. The spectrum is analyzed in terms of intensities of nanotube-related peaks, background and pi-carbon peak; the latter two mostly originate from non-nanotube carbon.
2.Carbon nanotubes as a black body

An ideal black body should have emissivity or absorbance of 1.0, which is difficult to attain in practice, especially in a wide spectral range. Vertically aligned "forests" of single-wall carbon nanotubes can have absorbances of 0.98–0.99 from the far-ultraviolet (200 nm) to far-infrared (200 μm) wavelengths. By coating Super black( a chemically etched nickel-phosphorus) the absorption of 1.0 can be achieved.

These SWNT forests (buckypaper) were grown by the super-growth CVD method to about 10 μm height. Two factors could contribute to strong light absorption by these structures: (i) a distribution of CNT chiralities resulted in various bandgaps for individual CNTs. Thus a compound material was formed with broadband absorption. (ii) Light might be trapped in those forests due to multiple reflections.

3.Luminescence

 

The Photoluminescence map of single-wall carbon nanotubes.  Can be help ful in identifying the nanotube semiconducting nanotubes with indices (n,m). The PL measurements do not detect other nanotubes with  indices n = m or mExcitation mechanism.Hence Photoluminescence (PL) is one of the important tools for nanotube characterization.

The excitation  mechnism of PL

 The excitation  mechnism of PL occurs as follows: an electron in a nanotube absorbs excitation light via S22 transition, creating an electron-hole pair (exciton). Both electron and hole rapidly relax (via phonon-assisted processes) from c2 to c1 and from v2 to v1 states, respectively. Then they recombine through a c1 − v1 transition resulting in light emission.

No excitonic luminescence can be produced in metallic tubes — electron can be excited, thus resulting in optical absorption, but the hole is immediately filled by another electron out of many available in metal. Therefore no exciton is produced .

 

properties

1.Photoluminescence, optical absorption and Raman scattering from SWCNT is linearly polarized along the tube axis..

2.PL is quick: relaxation typically occurs within 100 picoseconds.

     3.PL efficiency is usually low (~0.01%).

     4. The spectral range of PL is rather wide. Emission wavelength can vary between 0.8and 2.1 micrometers depending on the nanotube structure.

     5. Interaction between nanotubes or between nanotube and another material (e.g., substrate) quenches PL.Hence, PL is not observed in multi-wall carbon nanotubes.

6. PL from double-wall carbon nanotubes strongly dependsthe method of preparation.     For  eg;CVD grown DWCNTs show emission both from inner and outer shells. Position of the (S22, S11) PL peaks depends slightly (within 2%) on the nanotube environment (air, dispersant, etc.). However, the shift depends on the (n, m) index, and thus the whole PL map not only shifts, but also warps upon changing the CNT medium.

Applications of photoluminecense

PL is widely used to deduce (n, m) indexes: first nanotubes are isolated (dispersed) using an appropriate chemical agent ("dispersant") to reduce the intertube quenching. Then PL is measured, scanning both the excitation and emission energies and thereby producing a PL map. The ovals in the map define (S22, S11) pairs, which unique identify (n, m) index of a tube. The data of Weisman and Bachillo are conventionally used for the identification.

Sensitization

Optical properties, including the PL efficiency, can be modified by encapsulating organic dyes (carotene, lycopene, etc.) inside the tubes. Efficient energy transfer occurs between the encapsulated dye and nanotube — light is efficiently absorbed by the dye and without significant loss is transferred to the SWCNT. Thus potentially, optical properties of a carbon nanotube can be controlled by encapsulating certain molecule inside it.

Cathodoluminescence

Cathodoluminescence (CL) — light emission excited by electron beam — is a process commonly observed in TV screens. An electron beam can be finely focused and scanned across the studied material. This technique is widely used to study defects in semiconductors and nanostructures with nanometer-scale spatial resolution. It would be beneficial to apply this technique to carbon nanotubes. However, no reliable CL, i.e. sharp peaks assignable to certain (n, m) indexes, has been detected from carbon nanotubes yet.

Electroluminescence

If appropriate electrical contacts are attached to a nanotube, electron-hole pairs (excitons) can be generated by injecting electrons and holes from the contacts. Subsequent exciton recombination results in electroluminescence (EL). Electroluminescent devices have been produced from single nanotubes.

 Raman spectrum of single-wall carbon nanotubes

Raman spectroscopy has good spatial resolution (~0.5 micrometers) and sensitivity  to single nanotubes; it requires minimum sample preparation and is rather informative. Raman spectroscopy is the most popular technique of carbon nanotube characterization. Raman scattering in SWCNTs is resonant, i.e., only those tubes are probed which have one of the bandgaps equal to the exciting laser energy. Similar to photoluminescence mapping, the energy of the excitation light can be scanned in Raman measurements, thus producing Raman maps. Those maps also contain oval-shaped features uniquely identifying (n, m) indexes. Contrary to PL, Raman mapping detects not only semiconducting but also metallic tubes, and it is less sensitive to nanotube bundling than PL.

 

.

Anti-Stokes scattering

All the above Raman modes can be observed both as Stokes and anti-Stokes scattering. As mentioned above, Raman scattering from CNTs is resonant in nature, i.e. only tubes whose band gap energy is similar to the laser energy are excited. The difference between those two energies, and thus the band gap of individual tubes, can be estimated from the intensity ratio of the Stokes/anti-Stokes line. This estimate however relies on the temperature factor (Boltzmann factor), which is often miscalculated - focused laser beam is used in the measurement, which can locally heat the nanotubes without changing the overall temperature of the studied sample.

 

.

G mode:

G mode (gG from graphite)corresponds to planar vibrations of carbon atoms and is present in most graphite-like materials. G band in SWCNT is shifted to lower frequencies relative to graphite (1580 cm−1) and is split into several peaks. The splitting pattern and intensity depend on the tube structure and excitation energy; they can be used, though with much lower accuracy compared to RBM mode, to estimate the tube diameter and whether the tube is metallic or semiconducting

Rayleigh scattering

Carbon nanotubes have very largeaspect ratio, i.e., their length is much larger than their diameter. Consequently, as expected from the classical electromagnetic theory, elastic light scattering (or Rayleigh scattering) by straight CNTs has anisotropic angular dependence, and from its spectrum, the band gaps of individual nanotubes can be deduced.

References

1. . http://gltrs.grc.nasa.gov/reports/1996/CR-198469.pdf. 
2. ^ "IUPAC Compendium of Chemic1. Randall L. Vander Wal (1996). "Soot Precursor Material: Spatial Location via Simultaneous LIF-LII Imaging and Characterization via TEM: NASA Contractor Report 198469"al Terminology 2nd Edition (1997) diamond-like carbon films". http://www.iupac.org/goldbook/D01673.pdf. 
3. ^ "Bucky Balls". http://www.3rd1000.com/bucky/bucky.htm. Retrieved 2009-08-01. 
4. ^ Bianconi P et al. (2004). "Diamond and Diamond-like Carbon from a Preceramic Polymer". Journal of the American Chemical Society 126 (10): 3191–3202. doi:10.1021/ja039254l. PMID 15012149. 
5. ^ Nur, Yusuf (2008). "Facile Synthesis of Poly(hydridocarbyne): A Precursor to Diamond and Diamond-like Ceramics". Journal of Macromolecular Science Part A 45: 358. doi:10.1080/10601320801946108. 
6. ^ Nur, Yusuf (2009). "Electrochemical polymerizatıon of hexachloroethane to form poly(hydridocarbyne): a pre-ceramic polymer for diamond production". Journal of Materials Science 44: 2774. doi:10.1007/s10853-009-3364-4. 
7. ^ Gray, Theodore (September 2009). "Gone in a Flash". Popular Science: 70. 
8. ^ Correa, Aa; Bonev, Sa; Galli, G (Jan 2006). "Carbon under extreme conditions: phase boundaries and electronic properties from first-principles theory" (Free full text). Proceedings of the National Academy of Sciences of the United States of America 103 (5): 1204–8. doi:10.1073/pnas.0510489103. ISSN 0027-8424. PMID 16432191. PMC 1345714. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=16432191. 
9. ^ Johnston, Roy L. (1989). "Superdense carbon, C8: supercubane or analog of .gamma.-silicon?". Journal of the American Chemical Society 111: 810. doi:10.1021/ja00185a004. 
10. ^ Liu, P. (2008). "Synthesis of Body-Centered Cubic Carbon Nanocrystals". Crystal Growth & Design 8: 581. doi:10.1021/cg7006777. 
11. ^ Liu, P; Cao, Yl; Wang, Cx; Chen, Xy; Yang, Gw (Aug 2008). "Micro- and nanocubes of carbon with C8-like and blue luminescence". Nano letters 8 (8): 2570–5. doi:10.1021/nl801392v. ISSN 1530-6984. PMID 18651780. 
12. ^ *Openov, Leonid A.; Elesin, Vladimir F. (1998). "Prismane C8: A new form of carbon?". JETP Letters 68: 726. doi:10.1134/1.567936. http://www.jetpletters.ac.ru/ps/969/article_14784.pdf. 
13. External links
14. http://www.dendritics.com/scales/c-allotropes.asp

http://cst-www.nrl.navy.mil/lattice/struk/carbon.html

diamond 3D animation.

RABIYA TANVEER.                                                               

LECTURER IN PHYSICS

CHAITANYA DEGREE AND P.G COLLEGE

HNK,WARANGAL,INDIA.

AFFILIATION:

1.NANO SCIENCE & TECHNOLOGY CONSORTIUM,

NOIDA,UP.INDIA.

2.PHOTONICS 21,EUROPEAN TECHNOLOGY PLATFORM. EMAIL:munaizag@gmail.com                      

 

 

 

About the Author

lecturer in physics & electronics dept. of physics & electronics, chaitanya degree & p.g college, kishan pura ,hanamkonda, warangal.A.P.