‘Underwater noise is a global environmental issue that has to be addressed if we are to take advantage of the huge potential of ocean energy,’ said EU commissioner for research, innovation and science Máire Geoghegan-Quinn.
Ireland has one of highest concentrations of wave energy in the world, presenting a significant opportunity to expand its renewable energy portfolio and develop new industry capabilities,’ said Prof Owen Lewis, chief executive officer of SEAI.
Read more:Project assesses impact of wave energy conversion noise | News | The Engineer
Monday, 31 October 2011
Thursday, 27 October 2011
Giant Waterworld Around Naked Eye Star
Giant Waterworld Confirmed Around Naked Eye Star - Technology Review
"55 Cancri A is a Sun-like star some 40 light years away. It has an apparent magnitude of about 6 and so is visible to the naked eye in the constellation of Cancer.
This star is unusual in that it is just one of a handful that are known to have at least 5 planets. The innermost of these planets--55 Cancri e--was discovered in 2004 and has since had plenty of attention from astronomers. Various groups have observed the the changes in radial velocity that it causes its parent star. This tells them about that it orbits its star every 18 hours and that its mass is about 8 times Earth's or about half Neptune's."
"The innermost planet around 55 Cancri A is almost certainly an exotic waterworld with a radius about twice Earth's, say astronomers"
Tuesday, 18 October 2011
La transizione da liquido isotropo a smettico
La transizione da liquido isotropo a smettico
Amelia Carolina Sparavigna
Dipartimento di Fisica
Politecnico di Torino
Breve discussione della transizione di fase diretta dal liquido isotropo alla mesofase smettica, con osservazioni al microscopio polarizzatore.
I cristalli liquidi sono materiali composti di molecole di forma allungata, come bastoncini, oppure discoidale. Essi sono caratterizzati dalla presenza di mesofasi tra la fase liquida isotropa e quella cristallina. Tipiche mesofasi sono la fase nematica e quella smettica. La fase nematica ha i centri delle molecole che assumono posizioni arbitrarie, mentre gli assi delle molecole tendono a orientarsi nella stessa direzione. Nello smettico, le molecole si dispongono con i loro centri su piani definiti. Gli assi delle molecole hanno una direzione specifica rispetto al piano. Se la direzione è perpendicolare al piano, si dice che la fase è smettica A, se invece l’asse è inclinato, la fase è smettica B. La fase smettica è quindi più ordinata della nematica, ma più disordinata di un cristallo. Vi sono alcuni materiali termotropici in cui la fase nematica non c'è, ma si ha solo una fase smettica. Riscaldando o raffreddando il campione, si passa dalla fase smettica a quella liquido o viceversa, saltando la fase nematica.
Vediamo che cosa si può osservare col microscopo polarizzatore, quando si passa della fase liquida ordinaria, dove le molecole sono disordinate sia in posizione sia in orientamento, nella fase liquido-cristallina. La fase liquida ordinaria è detta “liquido isotropo”. Il cristallo liquido è preparato tra due vetrini e posto, all’interno di un termostato, sotto il microscopio, tra i due filtri polarizzatori. Lo spessore del materiale è di pochi micron. Il campione è riscaldato fino a raggiungere la fase liquida ordinaria. Questa fase, se vista al microscopio con i filtri polarizzatori incrociati, appare come un nero uniforme. L’isotropia ottica del materiale permette l’estinzione completa della luce. Se si raffredda il liquido ed esso passa nella fase nematica, si vedono comparire delle bolle colorate. Dove ci sono le bolle, il materiale è già nematico. Le bolle crescono fino a che tutto il materiale è nematico.
Transizione da liquido isotropo, che appare nero nella foto, a nematico, che è colorato. Il cristallo liquido è il 12OBAC (alkyloxybenzoic acid).
Il nematico è otticamente anisotropo. Il materiale modifica la luce che polarizzata dal primo filtro del microscopio. Il secondo non riesce più a estinguere tutta la luce. Il materiale appare colorato per via di fenomeni d’interferenza. Cosa si vede quando si passa del liquido isotropo allo smettico? Dato che ci sono diverse fasi smettiche, quello che si vede dipende dalla fase.
Smettico A
Utilizziamo un oxadiazolo, che ha la transizione diretta dalla fase isotropa a quella smettica. Il materiale ha una fase smettica di tipo A. Al microscopio polarizzatore, questo materiale mostra una fase caratterizzata da domini a ventaglio (in letteratura si trovano definiti come “fan” oppure “focal-conic”).
Domini “focal-conic” nella fase smettica.
Aumentando la temperatura, portiamo il campione nella fase liquida isotropa. Il campione diventa nero. Cominciamo a raffreddare lentamente il campione per portarlo nella fase smettica. Nel campo visivo del microscopio appaiono i “batonnets”, che cominciamo a crescere nella fase isotropa.
Batonnets della fase smettica che crescono nella fase isotropa (a sinistra). I domini crescono e si uniscono a formare la tessitura focal-conic.
Questi domini crescono e si uniscono insieme fino a formare la tessitura, ossia l’insieme dei domini osservati al microscopio polarizzatore, della fase smettica. I domini sono in questo caso focal-conic.
Smettico C
La tessitura vista sopra non è l’unica mostrata dalla fase smettica. Prendiamo un altro materiale, anche lui avente la transizione diretta liquido isotropo - smettico. Il materiale utilizzato è il 16OBAC della famiglia degli acidi ossibenzoici alchilici (alkyloxybenzoic). Il materiale è cristallino fino a 90 °C e poi passa nella fase smettica C.
A sinistra la fase cristallina del 16OBAC; a destra la fase smettica osservata in riscaldamento dalla fase cristallina.
Alla temperatura di 131 °C diventa un liquido isotropo, non ha quindi fase nematica. Questo è dovuto al fatto che le molecole sono così lunghe da mantenere l'ordine smettico fino ad alta temperatura, vincendo la tendenza al disordine dovuta all'agitazione termica. In raffreddamento, la fase smettica compare dalla fase isotropa: si osservano delle strutture ramificate che compaiono nel campo nero della cella vista tra polarizzatori incrociati.
Ecco come cresca la fase smettica nella fase isotropa.
La crescita della fase smettica dalla fase isotopa vista ad un ingrandimento maggiore.
La sequenza mostra l'evoluzione della struttura ramificata, quando si abbassa la temperatura (0.5 gradi al minuto).
E’ interessante notare che la fase smettica che si forma in raffreddamento ha una tessitura differente da quella che si osserva in riscaldamento. La tessitura è di tipo schlieren: poiché la fase è smettica, ci sono solo difetti con carica 1. Possiamo quindi distinguerla dalla fase nematica, che è simile, perché questa ha anche i difetti 1/2.
Fase smettica del 16OBAC che si forma in raffreddamento. La tessitura è di tipo schiere, con i soli difetti con carica 1.
Discussione
Il processo di crescita delle mesofasi dalla fase isotropa è un problema interessante e forse poco studiato ancora [1]. Questo processo ha due fasi, quella di nucleazione e quella di accrescimento. Esse sono state ben studiate per i processi di cristallizzazione dal liquido isotropo. Nella fase di nucleazione succede che, all'interno del liquido si creano dei punti in cui la concentrazione locale è maggiore. Questi punti sono chiamati cluster. Crescendo, si creano dei nuclei che rispecchiano fedelmente l'ordine del cristallo. Sono piccoli cristallini di dimensioni microscopiche.
Anche le mesofasi hanno i loro nuclei. Per quanto riguarda i nematici, di solito si osservano delle piccolissime gocce circolari, che si formano nel liquido isotropo e che poi si uniscono a formare la fase nematica. Anche se il nematico è anisotropo come orientazione, è disordinato come posizione. Immaginiamo le molecole del nematico come dei bastoncini. Quando esse sono nella fase liquida isotropa, i loro centri sono disordinati, come anche le loro direzioni. Al decrescere della temperatura, quando il materiale arriva alla transizione di fase, le molecole possono girare i loro assi lunghi senza doversi spostare. Questo può avvenire nello stesso modo in tutte le direzioni dello spazio. Il nucleo di nematico cresce nel liquido isotropo con una simmetria sferica.
Nello smettico invece, l’ordine locale è molto diverso. Ci sono dei piani microscopici, su cui si devono sistemare i centri delle molecole. Le molecole devono orientarsi ma anche spostare i loro centri per formare i piani. I clusters iniziali possiedono quindi una direzione privilegiata, quella perpendicolare ai piano dello smettico. Ecco quindi che possono comparire i nuclei come batonnets.
E’ molto interessante la crescita dello smettico C, che appare come una struttura ramificata. Sicuramente sono necessari ulteriori studi per determinare meglio le caratteristiche dei nuclei.Riferimenti
Cristalli liquidi, http://www.treccani.it/enciclopedia/cristalli-liquidi/
[1] I Dierking, C Russell, Universal scaling laws for the anisotropic growth of SmA liquid crystal bâtonnets, Physica B: Condensed Matter, Volume 325, January 2003, Pages 281-286.
Friday, 14 October 2011
Mesophases transitions
An interesting transition is the texture transition inside the nematic phase. We observe in some liquid crystalline compounds a transition from a low-temperature nematic texture which looks like a texture of a smectic phase to a high temperature nematic Schlieren texture. Compounds that have the texture transition are the alkyloxybenzoic acids. Here, you can see a movie of the texture transtion inside the nematic phase of 6OBAC. The sample is heated from the crystal phase. We can see the smectic pahse and then the two following nematic subphases. Click on the image to see the movie.
More details in my papers:
Texture transitions in binary mixtures of 6OBAC with compounds of its homologous series A. Sparavigna; A. Mello; B. Montrucchio Phase Transitions: A Multinational Journal, 1029-0338 Volume 80, Issue 3, 2007, Pages 191 – 201 Abstract | |
Texture transitions in the liquid crystalline alkyloxybenzoic acid 6OBAC A. Sparavigna; A. Mello; B. Montrucchio Phase Transitions: A Multinational Journal, 1029-0338 Volume 79, Issue 4, 2006, Pages 293 – 303 Abstract | |
A new image processing method for enhancing the detection sensitivity of smooth transitions in liquid crystals Liquid Crystals, 1366-5855, Volume 24, Issue 6, 2001, Pages 841 – 852 Abstract | |
A novel order transition inside the nematic phase of trans -4-hexylcyclohexane-1-carboxylic acid discovered by image processing Liquid Crystals, 1366-5855, Volume 25, Issue 5, 2001, Pages 613 – 620 Abstract | |
In the following, three movies show a transition on cooling from the nematic to the smectic phase of an oxadiazole compound. We see a transition from the nemtic to a smectic phase with toric domains.
Clink on images to launch the movies.
For more details, these are my articles: | |
Growth of toric domains in mesophases of oxadiazoles A. Sparavigna; A. Mello; B. Montrucchio Phase Transitions: A Multinational Journal 1029-0338, Volume 81, Issue 5, 2008, Pages 471 – 477 Abstract | |
Fan-shaped, toric and spherulitic textures of mesomorphic oxadiazoles A. Sparavigna; A. Mello; B. Montrucchio Phase Transitions: A Multinational Journal 1029-0338, Volume 80, Issue 9, 2007, Pages 987 – 998 Abstract |
Amelia Carolina Sparavigna
Saturday, 8 October 2011
Of the Education of an Engineer
"Architecture is a science arising out of many other sciences, and adorned with much and varied learning; by the help of which a judgment is formed of those works which are the result of other arts. Practice and theory are its parents. Practice is the frequent and continued contemplation of the mode of executing any given work, or of the mere operation of the hands, for the conversion of the material in the best and readiest way. Theory is the result of that reasoning which demonstrates and explains that the material wrought has been so converted as to answer the end proposed. Wherefore the mere practical architect is not able to assign sufficient reasons for the forms he adopts ; and the theoretic architect also fails, grasping the shadow instead of the substance. He who is theoretic as well as practical, is therefore doubly armed; able not only to prove the propriety of his design, but equally so to carry it into execution.
In architecture, as in other arts, two considerations must be constantly kept in view; namely, the intention, and the matter used to express that intention: but the intention is founded on a conviction that the matter wrought will fully suit the purpose; he, therefore, who is not familiar with both branches of the art, has no pretension to the title of architect. An architect should be ingenious, and apt in the acquisition of knowledge. Deficient in either of these qualities, he cannot be a perfect master.
He should be a good writer, a skillful draftsman, versed in geometry and optics, expert at figures, acquainted with history, informed on the principles of natural and moral philosophy, somewhat of a musician, not ignorant of the sciences both of law and physics, nor of the motions, laws, and relations to each other, of the heavenly bodies. By means of the first named acquirement, he is to commit to writing his observations and experience, in order to assist his memory. Drawing is employed in representing the forms of his designs. Geometry affords much aid to the architect: to it he owes the use of the right line and circle, the level and the square; whereby his delineations of buildings on plane surfaces are greatly facilitated. The science of optics enables him to introduce with judgment the requisite quantity of light, according to the aspect. Arithmetic estimates the cost, and aids in the measurement of the works; this, assisted by the laws of geometry, determines those abstruse questions, wherein the different proportions of some parts to others are involved. Unless acquainted with history, he will be unable to account for the use of many ornaments which he may have occasion to introduce. ...
Many other matters of history have a connexion with architecture, and prove the necessity of its professors being well versed in it. Moral philosophy will teach the architect to be above meanness in his dealings, and to avoid arrogance: it will make him just, compliant and faithful to his employer ; and what is of the highest importance, it will prevent avarice gaining an ascendancy over him: for he should not be occupied with the thoughts of filling his coffers, nor with the desire of grasping every thing in the shape of gain, but, by the gravity of his manners, and a good character, should be careful to preserve his dignity. In these respects we see the importance of moral philosophy; for such are her precepts. That branch of philosophy which the Greeks call phusiologia, or the doctrine of physics, is necessary to him in the solution of various problems; as for instance, in the conduct of water, whose natural force, in its meandering and expansion over flat countries, is often such as to require restraints, which none know how to apply, but those who are acquainted with the laws of nature: nor, indeed, unless grounded in the first principles of physics, can he study with profit the works of Ctesibius, Archimedes, and many other authors who have written on the subject.
Music assists him in the use of harmonic and mathematical proportion. It is, moreover, absolutely necessary in adjusting the force of the balistae, catapultae, and scorpions...
Astronomy instructs him in the points of the heavens, the laws of the celestial bodies, the equinoxes, solstices, and courses of the stars; all of which should be well understood, in the construction and proportions of clocks. Since, therefore, this art is founded upon and adorned with so many different sciences, I am of opinion that those who have not, from their early youth, gradually climbed up to the summit, cannot, without presumption, call themselves masters of it. Perhaps, to the uninformed, it may appear unaccountable that a man should be able to retain in his memory such a variety of learning ; but the close alliance with each other, of the different branches of science, will explain the difficulty. For as a body is composed of various concordant members, so does the whole circle of learning consist in one harmonious system. Wherefore those, who from an early age are initiated in the different branches of learning, have a facility in acquiring some knowledge of all, from their common connexion with each other...
For in such a variety of matters, it cannot be supposed that the same person can arrive at excellence in each, since to be aware of their several niceties and bearings, cannot fall within his power. We see how few of those who profess a particular art arrive at perfection in it, so as to distinguish themselves: hence, if but few of those practising an individual art, obtain lasting fame, how should the architect, who is required to have a knowledge of so many, be deficient in none of them, and even excel those who have professed any one
exclusively. ...
I beseech you, O Caesar, and those who read this my work, to pardon and overlook grammatical errors; for I write neither as an accomplished philosopher, an eloquent rhetorician, nor an expert grammarian, but as an architect: in respect, however, of my art and its principles, I will lay down rules which may serve as an authority to those who build, as well as to those who are already somewhat acquainted with the science."
From "The Architecture", by Marcus Vitruvius Pollio
In architecture, as in other arts, two considerations must be constantly kept in view; namely, the intention, and the matter used to express that intention: but the intention is founded on a conviction that the matter wrought will fully suit the purpose; he, therefore, who is not familiar with both branches of the art, has no pretension to the title of architect. An architect should be ingenious, and apt in the acquisition of knowledge. Deficient in either of these qualities, he cannot be a perfect master.
He should be a good writer, a skillful draftsman, versed in geometry and optics, expert at figures, acquainted with history, informed on the principles of natural and moral philosophy, somewhat of a musician, not ignorant of the sciences both of law and physics, nor of the motions, laws, and relations to each other, of the heavenly bodies. By means of the first named acquirement, he is to commit to writing his observations and experience, in order to assist his memory. Drawing is employed in representing the forms of his designs. Geometry affords much aid to the architect: to it he owes the use of the right line and circle, the level and the square; whereby his delineations of buildings on plane surfaces are greatly facilitated. The science of optics enables him to introduce with judgment the requisite quantity of light, according to the aspect. Arithmetic estimates the cost, and aids in the measurement of the works; this, assisted by the laws of geometry, determines those abstruse questions, wherein the different proportions of some parts to others are involved. Unless acquainted with history, he will be unable to account for the use of many ornaments which he may have occasion to introduce. ...
Many other matters of history have a connexion with architecture, and prove the necessity of its professors being well versed in it. Moral philosophy will teach the architect to be above meanness in his dealings, and to avoid arrogance: it will make him just, compliant and faithful to his employer ; and what is of the highest importance, it will prevent avarice gaining an ascendancy over him: for he should not be occupied with the thoughts of filling his coffers, nor with the desire of grasping every thing in the shape of gain, but, by the gravity of his manners, and a good character, should be careful to preserve his dignity. In these respects we see the importance of moral philosophy; for such are her precepts. That branch of philosophy which the Greeks call phusiologia, or the doctrine of physics, is necessary to him in the solution of various problems; as for instance, in the conduct of water, whose natural force, in its meandering and expansion over flat countries, is often such as to require restraints, which none know how to apply, but those who are acquainted with the laws of nature: nor, indeed, unless grounded in the first principles of physics, can he study with profit the works of Ctesibius, Archimedes, and many other authors who have written on the subject.
Music assists him in the use of harmonic and mathematical proportion. It is, moreover, absolutely necessary in adjusting the force of the balistae, catapultae, and scorpions...
Astronomy instructs him in the points of the heavens, the laws of the celestial bodies, the equinoxes, solstices, and courses of the stars; all of which should be well understood, in the construction and proportions of clocks. Since, therefore, this art is founded upon and adorned with so many different sciences, I am of opinion that those who have not, from their early youth, gradually climbed up to the summit, cannot, without presumption, call themselves masters of it. Perhaps, to the uninformed, it may appear unaccountable that a man should be able to retain in his memory such a variety of learning ; but the close alliance with each other, of the different branches of science, will explain the difficulty. For as a body is composed of various concordant members, so does the whole circle of learning consist in one harmonious system. Wherefore those, who from an early age are initiated in the different branches of learning, have a facility in acquiring some knowledge of all, from their common connexion with each other...
For in such a variety of matters, it cannot be supposed that the same person can arrive at excellence in each, since to be aware of their several niceties and bearings, cannot fall within his power. We see how few of those who profess a particular art arrive at perfection in it, so as to distinguish themselves: hence, if but few of those practising an individual art, obtain lasting fame, how should the architect, who is required to have a knowledge of so many, be deficient in none of them, and even excel those who have professed any one
exclusively. ...
I beseech you, O Caesar, and those who read this my work, to pardon and overlook grammatical errors; for I write neither as an accomplished philosopher, an eloquent rhetorician, nor an expert grammarian, but as an architect: in respect, however, of my art and its principles, I will lay down rules which may serve as an authority to those who build, as well as to those who are already somewhat acquainted with the science."
From "The Architecture", by Marcus Vitruvius Pollio
Friday, 7 October 2011
Solid angle
A Lecture on Solid Angle, by Ben Kravitz
http://www.stanford.edu/~bkravitz/research/solidangle.pdf
"In order to talk about solid angles, we fi rst need to talk about projections. There are lots of diff erent kinds of projections, some of which you already know. We should begin with a very simple defi nition of what a projection is, and then we'll get more complex as we go along. A projection is the transformation of points and lines in one plane onto another plane by connecting corresponding points on the two planes with parallel lines".
http://www.stanford.edu/~bkravitz/research/solidangle.pdf
"In order to talk about solid angles, we fi rst need to talk about projections. There are lots of diff erent kinds of projections, some of which you already know. We should begin with a very simple defi nition of what a projection is, and then we'll get more complex as we go along. A projection is the transformation of points and lines in one plane onto another plane by connecting corresponding points on the two planes with parallel lines".
Wednesday, 5 October 2011
Theory and practice
From the post
Teaching: Theory or practice? by Marcus Wilson Aug 07
"What’s clear is that many teachers take the view that theory is the opposite of practice. Since, in teaching, it is clearly the practice that matters (since it’s what the students experience) this leads to the conclusion that theory is irrelevant and there is no benefit in engaging with it. ... The fallacy is the implicit assumption that theory and practice are unconnected. (I mean, you don’t have experimental physicists and theoretical physicists working in complete isolation from each other, so why expect that with teaching?) What you believe about student learning will influence the way you teach, whether you formally acknowledge it or not. That’s become clear for me as I think about my teaching practice. I have my own ‘beliefs’, or my own models, call them ‘theories’, of how students learn, and these influence how I teach."
Read the post at
http://sciblogs.co.nz/physics-stop/2011/08/07/teaching-theory-or-practice/
Teaching: Theory or practice? by Marcus Wilson Aug 07
"What’s clear is that many teachers take the view that theory is the opposite of practice. Since, in teaching, it is clearly the practice that matters (since it’s what the students experience) this leads to the conclusion that theory is irrelevant and there is no benefit in engaging with it. ... The fallacy is the implicit assumption that theory and practice are unconnected. (I mean, you don’t have experimental physicists and theoretical physicists working in complete isolation from each other, so why expect that with teaching?) What you believe about student learning will influence the way you teach, whether you formally acknowledge it or not. That’s become clear for me as I think about my teaching practice. I have my own ‘beliefs’, or my own models, call them ‘theories’, of how students learn, and these influence how I teach."
Read the post at
http://sciblogs.co.nz/physics-stop/2011/08/07/teaching-theory-or-practice/
Friday, 30 September 2011
Speed of neutrino and cosmic consequences
Let me report a part of the discussion on the speed of neutrinos by Wikipedia
"In September 2011 the OPERA collaboration released calculations showing velocities of 17-GeV and 28-GeV neutrinos exceeding the speed of light in their experiments. The authors write, "Despite the large significance of the measurement reported here and the stability of the analysis, the potentially great impact of the result motivates the continuation of our studies in order to investigate possible still unknown systematic effects that could explain the observed anomaly." This result had not been detected by previous experiments, and lies in contrast to several others. For instance, photons and neutrinos from SN 1987A were observed to have an agreement in transit time to about 1 part in 450 million, with even this difference being accounted for by light being impeded by the material of the star early in its journey. The OPERA results, in contrast, suggested that neutrinos were traveling faster than light by a factor of 1 in 40,000, i.e. that neutrino speed is 1.0000248(28) c. Had neutrinos from SN 1987A (a supernova, approximately 168,000 light-years from Earth, http://en.wikipedia.org/wiki/SN_1987A) traveled faster than light by this factor, they would have arrived at Earth several years before the photons; this was not observed to be the case. However, neutrinos from the supernova had orders of magnitude less energy than the neutrinos observed in the OPERA experiment, as the authors point out."
"In September 2011 the OPERA collaboration released calculations showing velocities of 17-GeV and 28-GeV neutrinos exceeding the speed of light in their experiments. The authors write, "Despite the large significance of the measurement reported here and the stability of the analysis, the potentially great impact of the result motivates the continuation of our studies in order to investigate possible still unknown systematic effects that could explain the observed anomaly." This result had not been detected by previous experiments, and lies in contrast to several others. For instance, photons and neutrinos from SN 1987A were observed to have an agreement in transit time to about 1 part in 450 million, with even this difference being accounted for by light being impeded by the material of the star early in its journey. The OPERA results, in contrast, suggested that neutrinos were traveling faster than light by a factor of 1 in 40,000, i.e. that neutrino speed is 1.0000248(28) c. Had neutrinos from SN 1987A (a supernova, approximately 168,000 light-years from Earth, http://en.wikipedia.org/wiki/SN_1987A) traveled faster than light by this factor, they would have arrived at Earth several years before the photons; this was not observed to be the case. However, neutrinos from the supernova had orders of magnitude less energy than the neutrinos observed in the OPERA experiment, as the authors point out."
Friday, 23 September 2011
Neutrino: fast and furious
Here the news of the day! Neutrinos are faster than light!
http://www.guardian.co.uk/science/2011/sep/23/faster-light-neutrinos
"Scientists at the Opera (Oscillation Project with Emulsion-tRacking Apparatus) experiment in Gran Sasso, Italy, found that beams of neutrinos sent to its detectors from Cern, 730km away in Geneva, arrived earlier than they should have."
http://www.guardian.co.uk/science/2011/sep/23/faster-light-neutrinos
"Scientists at the Opera (Oscillation Project with Emulsion-tRacking Apparatus) experiment in Gran Sasso, Italy, found that beams of neutrinos sent to its detectors from Cern, 730km away in Geneva, arrived earlier than they should have."
Thursday, 22 September 2011
Coherers as “energy catalyzers”
Coherers as “energy catalyzers”
Amelia Carolina Sparavigna
Dipartimento di Fisica,
Politecnico di Torino, Torino, Italy
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References
Amelia Carolina Sparavigna
Dipartimento di Fisica,
Politecnico di Torino, Torino, Italy
Abstract: A device defined as an “energy catalyzer”, able to give thermal energy at the expense of electric energy, has aroused a great popular interest. In fact, the confidence on this device does not allow its discussion. Some known features are intriguing, which can therefore become the starting point for a discussion on old coherers and the Branly effect. We could define the coherers as a sort of “energy catalyzers”.
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On Wednesday September 21, 2011, from the news of RAI, the Italian broadcaster, I learned that a new device for energy production was on the way for industrial developments. I had not immediately realized the features of this device, but I memorized the fact that it was based on water, nickel powders and current, that I saw sparkling in the video clip. After searching on the Web, I found that the announced device was the energy catalyzer, E-Cat, under patent request by its inventor, Andrea Rossi. The development of prototypes was due to the work of Rossi and Sergio Focardi, University of Bologna
The confidence on this device does not allow its discussion. And in fact, the aim of my paper is not a discussion on E-Cat, but on what the poor information on it suggested me. Some features of the device attracted my interest: they are the metal powders, the high temperatures and the sparks of electricity. In fact I read recently about all these things together in a old book published in 1904, entitled Elements of Physics, by Fernando Sanford, professor at the Stanford University, one of the members of the group of scientists who came there to create the pioneer faculty in 1891. In [4], I discussed the experiments of Sanford Sanford
"Take a glass tube of about a centimeter bore and six or eight centimeters long, fit the ends with corks through which copper wires can be passed, and fill the tube between the corks with brass or iron filings. Thrust copper wires through the corks and into the iron filings until their ends are one or two centimeters apart. Connect these wires in circuit with one or more voltaic cells and a tolerably sensitive galvanometer. The resistance of the filings to the passage of a current should be so great that the galvanometer is slightly, if at all, deflected. Bring an electric machine near, and pass sparks from one discharging knob into one of the wires which enter the tube. The resistance should fall so that the galvanometer is deflected through nearly 90°. This instrument is called a Coherer. The passage of the electric discharge into the small metallic particles in the tube apparently causes them to cling together so that they make better electric contact than before. After your coherer has become sensitive enough to allow the passage of a suitable current, increase its resistance again by tapping gently on the glass and causing the particles to separate. Then move the electric machine to a distance of a few feet from the coherer and turn the handle and cause sparks to pass between the discharging knobs of the machine. If your coherer has been properly adjusted, the galvanometer will be deflected again, showing that the resistance of the coherer has been again diminished. By a little care in the adjustment, and by using a sensitive galvanometer, the coherer will respond to a spark at a distance of several yards. ... The Coherer described above is similar to the receiver used in "wireless telegraphy." The Coherer is connected between a battery and a telegraph sounder, and is attached to a long wire or other conductor suspended at some height. A similar conductor is suspended at the sending station, and is connected with the spark gap of the electric machine or induction coil. The oscillations in the receiving conductor are accordingly partly due to resonance, and they are sufficient to lower the resistance of the coherer so that a signal can be made through it. An automatic tapper jars the particles apart, so that the signal is momentary unless the instrument is sensitized by another spark. "
Fig.1. The Coherer in the book written by F. Sanford.
The device described by Sanford Sanford is telling
In the work published in 2001 [7], Bardou and Boosé theoretically proposed that the tunnelling probability of a particle through a potential barrier could be enhanced by striking the particle when the centroid of its wave packet is reflecting on the barrier. This is applied to Branly effect as discussed in [6] in the following way. “In a granular metallic medium microscopic grains are electrically isolated one from the other by a metal oxide nanometric layer ... When a voltage is applied to the medium, electrons are accelerated and they do reflect on the potential barriers. At the time of the reflection, these electrons can be kicked forward or backward by the short electromagnetic pulses present in the external electromagnetic field. … The enhanced transmission induced by the momentum transfer produces an increased electrical current, that for some events become large enough to permit a local heating in the metal grains thanks to the Joule effect. Eventually a welding of the grains can occur and when a percolation path has formed the electrical resistance of the medium drops down going from an exponential dependence on the applied voltage to a linear one”. Reference 6 is also reporting that Auerbach demonstrated in 1898 that a coherer could be made conducting by an acoustic excitation in the audible range of the spectrum. According to [6], this means that acoustical waves, by giving vibrations to tunnel barriers between the metallic grains, could be responsible of an induced tunnelling.
Let us also consider the recent experiments with particle coherers by Falcon et al. [8]. They reported on observations of the electrical transport within a chain of metallic beads, which were slightly oxidised. As the applied current is increased, a transition from an insulating to a conductive state is observed. The authors are proposing that the transition comes from an electro-thermal coupling, at the micro-contacts between each bead. Due to these contacts, the current flows through them, generating a high local heating. This heating increases the local contact areas, enhancing the conduction. This current-induced temperature rise, up to 1050°C, results in the micro-soldering of the contact points, even for low voltages.
If we define an “energy catalyzer” as a device able to produce change in, or transform energy, the coherer acts in such a manner, where the catalyst is an electromagnetic pulse. Let us hope that as soon as possible, an open report on E-Cat is published, in order to understand the role of hydrogen in it. In this device, is any tunnelling present? Is it there a tunnelling able to give a fusion of nickel and hydrogen to have copper in a proton capture as told in [9]? Is there any kicking mechanism? What we find in [9] is that the paper is just reporting the results “obtained with a process and apparatus not described here (in [9]) in detail and protected by patent in 90 countries, consisting of a system whose heat output is up to hundred times the electric energy input. As a consequence, the principle of the conservation of energy ensures that processes involving other energy forms are occurring in our apparatus”. And in the conservation of energy we trust.
1. http://peswiki.com/index.php/Directory:Andrea_A._Rossi_Cold_Fusion_Generator
2. http://en.wikipedia.org/wiki/Energy_Catalyzer
3. http://www.wipo.int/pctdb/en/wo.jsp?IA=IT2008000532&DISPLAY=DESC
4. A.C. Sparavigna, Fernando Sanford and the "Kirlian effect", arXiv:1105.1266v1 [physics.pop-ph], http://arxiv.org/ftp/arxiv/papers/1105/1105.1266.pdf
5. http://en.wikipedia.org/wiki/Coherer
6. C. Hirlimann, Understanding the Branly effect, arXiv:cond-mat/0703495v1 [cond-mat.mtrl-sci], http://arxiv.org/ftp/cond-mat/papers/0703/0703495.pdf
7. D. Boosé and F. Bardou, A quantum evaporation effect, Europhys. Lett., 53, 1-7 (2001).
8. E. Falcon, B. Castaing, and M. Creyssels, Nonlinear electrical conductivity in a 1D granular medium, The European Physical Journal B, 38, 475-483 (2004)
9. S. Focardi and A. Rossi, A new energy source from nuclear fusion, http://www.lenr-canr.org/acrobat/FocardiSanewenergy.pdf
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