Newsgroup: it.discussioni.ingegneria
Titolo: Mentre noi discutiamo, questi faranno sicuramente i soldi ....

Il professor Hummel dell'universita' della Florida, assieme con alcuni 
suoi studenti ha scoperto come identificare buona parte degli esplosivi 
in commercio a distanza. 
La struttura di queste molecole per loro natura porta il materiale ad 
emettere dei "vapori" ben identificabili dai cani ....
Il signore in questione ha scoperto che illuminando con un laser 
"verde" questi "fumi" .... essi riemettono luce nel campo 
dell'infrarosso. 
Usando due sensori elimina poi la possibilita' di errore, controllando 
che nelle frequenze adiacenti non ci siano altri picchi.
Il rimando nel campo dell'infrarosso rimane ben confinato in determinate 
bande di frequenza piuttosto strette per tutte queste molecole.
Insomma, semplice, lineare (tanto che nessuno voleva credergli 
all'inizio) ora l'ha brevettato ..... 
Con un dispositivo del genere si possono facilemnte costruire porte 
automatiche che si chiudono in anticipo non appena "vedono" che arriva 
un terrorista o una valigia sospetta. Porte antiesplosione naturalmente.
Non male per salvaguardare aereoporti, centri commerciali, luoghi 
pubblici e chi piu' ne' ha piu' ne' metta.
Cosi', giusto per parlare di ingegneria vera e propria ogni tanto.
-- 
What the eyes see and the ears hear, the mind believes.

 Cosi', giusto per parlare di ingegneria vera e propria ogni tanto.
Polemico:
"Tra dire e fare c'è di mezzo il mare" dicevano.
La differenza è che qui si fa poco ma si parla tanto.
Dall'altra sponda dell'Atlantico fanno e poi lasciano dire a chi di
dovere.
Per conto mio la differenza tra noi e (per fare 1 esempio) loro è che
questi hanno le palle quadrate e una cultura che ti porta ad averle
anche se non ne hai.
Qui da noi al massimo c'è la cultura dell'aperitivo e della mamma che
ti stira la camicia.


LA differenza e' nel sistema; se li hai una idea, puoi:
1- rivolgerti ad universita' e/o aziende che magari ti mettono un buco a
disposizione per svilupparla; ovviamente se questa idea e' valida, ma c'e'
anche chi e' in grado di valutarla.
2- rivolgerti ad una banca per un finanziamento; qui ti finanziano solo sei
hai un crack sicuro (cirio e parmalat docent)
 
--------------------------------
Inviato via 
http://arianna.libero.it/usenet/

http://www.eetimes.com/showArticle.jhtml?articleID=50500050
Photoluminescent method detects explosives at a distance 
By R. Colin Johnson 
EE Times 
October 18, 2004 (9:31 AM EDT)    
 
Portland, Ore. — Experience in photoluminescent spectroscopy has helped 
university researchers bring to light a method by which explosives can 
be detected at a distance.
In contrast, to detect the presence of explosives today, airport and 
other screeners must swab an object like a suitcase or clothing, use a 
dog to sniff it, or blast puffs of air across a filter that traps 
airborne explosive particles. 
The advantages of the photoluminescence-based explosive detection method 
are that it can be remotely applied and that it requires neither time-
consuming and expensive machines nor trained dogs. All you do is shine a 
laser on an object and watch for the photoluminescent "signature" 
distinctive of explosives. Whether it's an approaching ship, a suitcase, 
a moving car or a pile of trash half a mile up the road, if you can 
shine a green laser on it, professor Rolf Hummel at the University of 
Florida (Gainesville) says he can tell you whether it's an explosive 
device. 
Hummel, an engineering professor emeritus specializing in materials 
science, was intrigued by a U.S. Army Research Office challenge to 
universities to find an inexpensive, quick and reliable explosive-
detection system. With his lab's high-resolution photoluminescent meter, 
one of his students performed a simple test that no major lab had 
thought to perform before: Shine a green laser on an explosive and see 
if it glows like a white shirt under a black light, but in the infrared. 
When Hummel's assistant at the Nanoscale Devices and Novel Engineered 
Materials center at the University of Florida performed the test, it 
worked the first time, the second time and every time thereafter. No 
false alarms yet. 
Hummel performed the work with University of Florida professor Paul 
Holloway and doctoral candidates Anna Fuller and Kwanghoon Kim. 
The novelty of Hummel's discovery stems from the fact that no one knew 
explosives were photoluminescent in the infrared — let alone that the 
vapors forced out of them by their very reactive nature could be made to 
glow from a distance with a laser. 
No false positives 
Although photoluminescence is a well-known field — that's how 
fluorescent tubes work — no one thought to check to see if explosives 
glowed in the infrared when zapped with a green laser. Hummel said his 
years of experience suggested this combination when he started thinking 
about what a lifesaver such a device might be. 
Chuck Schau, a scientist at Raytheon Missile System's Radiation 
Technology Laboratory, actually had conducted experiments on detecting 
explosives using photoluminescence before Hummel's discovery. He did not 
have the specialized detectors present in the Nanoscale Devices and 
Novel Engineered Materials center at the University of Florida, however, 
so he missed observing the distinctive infrared peak that enables 
Hummel's claim of freedom from false positives. Raytheon is now 
considering licensing the technology for military use. 
"This discovery is very exciting for the field of remote detection," 
Schau said. 
The researchers have proven that the effect works with TNT, 
nitroglycerin and the plastic explosives trinitrofenil-Nmetilnitramina 
(Tetryl), hexahydro-trinitro-triazine (RDX), octahydro-
tetranitrotetrazocine (HMX) and pentaerythrol tetranitrate (PETN). 
Photoluminescence works by adding energy to a molecule with a high-
energy wavelength of light, then allowing that molecule to fall back 
into its ground state by emitting a photon of a different, distinctive 
wavelength. For instance, the ultraviolet rays from the mercury vapor in 
a fluorescent bulb bump the phosphor coating on the inside of the tube 
into a higher energy state. When the coating molecules drop back into 
their ground state, they emit a visible photon, thereby making a light 
bulb. 
Similarly, in Hummel's approach a high-energy green laser (325- to 532-
nanometer wavelength) adds energy to molecules floating in the air and 
on the surface of anything, including people, luggage and approaching 
vehicles. If explosives are involved in any way, Hummel claims, his 
detector will set off an alarm triggered by a glow that has a unique 
signature. 
Over the past year Hummel has tested his technique on everything he can 
image might end up in a suitcase, from benzene, naphthalene, nail 
polish, perfume, lighter fluid, rubber cement, acetone, toluene, 
fertilizer on golf shoes, sugar, baking soda, polyvinyl pyrrolidone 
(PVP), paint thinner and more — with no false positives yet. 
"It turns out that all explosives use groups of nitrogen molecules 
bonded to two oxygen molecules, which makes them very reactive — they 
can't help but seep out into the air around anything concealing them. 
When our green laser hits these molecules they photoluminesce at the 
705-nm wavelength. Anything else that radiates at that frequency also 
radiates at nearby frequencies. Only explosives emit in this very narrow 
band," said Hummel. 
As a consequence, Hummel's detector could theoretically sense a single 
molecule from an explosive's "aroma" without fear of false positives, by 
using two sensors — one for explosives and one to prevent false 
positives. The primary sensor has a filter so it only senses exactly 
705-nm wavelengths, thus "arming" the alarm. But the alarm is only set 
off if a second, "fail-safe" sensor verifies that there is no equally 
strong radiation at wavelengths adjacent to 705 nm, thus preventing 
false positives, according to Hummel. 
"This invention is almost a year old now, because at first people here 
did not believe us — that no one had thought of this before. But when 
they checked the literature and found we were right, they told us we 
couldn't tell anybody until they got a patent on it," said Hummel. 
In the ensuing year, Hummel's group at the University at Florida built 
several successful prototypes. Even without special equipment, the 
researchers were able to trigger the effect by merely donning a 
soldier's night-vision goggles and shining a green presentation laser on 
an explosive. 
Eventually, Hummel envisions sensors mounted outside doors at airports, 
to scan people and vehicles before they even get close to the terminal. 
By doing so at a distance, automatic door closers, blast barriers and 
police units could be automatically deployed before bombers get close to 
secure areas. 


 Cosi', giusto per parlare di ingegneria vera e propria ogni tanto.
Ricerca con immediato utilizzo pratico, probabilmente finaziata da
privati... c'è gente che ha occupato le università per impedire questi
orrori ;-)

 wrote in message 
Ciao GG, sono Alberto di Udine.
Mi rimandi un tuo indirizzo , che ho furbescamnete perso?
Ti ho mandato un post a lolo@ecc ma sebra inattivo.

 Ti ho mandato un post a lolo@ecc ma sebra inattivo.
 
C'e' posta per te ....


 C'e' posta per te ....
Alle 12 di venerdi 22 , non mi è ancora arrivata.
Un indirizzo valido è 
nev...@libero.it
ciao