Pipes et ballons

🔞 TOUTES LES INFORMATIONS CLIQUEZ ICI 👈🏻👈🏻👈🏻

Pipes et ballons
From Wikipedia, the free encyclopedia


^ Jump up to: a b c d e Merritt, D. R. ; Weinhaus, F. (October 1978), "The Pressure Curve for a Rubber Balloon" , American Journal of Physics , 46 (10): 976–978, Bibcode : 1978AmJPh..46..976M , doi : 10.1119/1.11486

^ James, H. M.; Guth, E. (April 1949), "Simple presentation of network theory of rubber, with a discussion of other theories" , Journal of Polymer Science , 4 (2): 153–182, Bibcode : 1949JPoSc...4..153J , doi : 10.1002/pol.1949.120040206 , archived from the original on 2013-01-05

^ Bower, Allan F. (2009). Applied Mechanics of Solids . Taylor & Francis . ISBN 978-1-4398-0247-2 .

^ Jump up to: a b Weinhaus, F.; Barker, W. (October 1978), "On the Equilibrium States of Interconnected Bubbles or Balloons" (PDF) , American Journal of Physics , 46 (10): 978–982, Bibcode : 1978AmJPh..46..978W , doi : 10.1119/1.11487 , archived from the original (PDF) on 2011-09-13

^ Houwink, R.; de Decker, H. K. (1971). Elasticity, Plasticity and Structure of Matter . Cambridge University Press . ISBN 052107875X .

^ Dreyer, W.; Müller, I.; Strehlow, P. (1982), "A Study of Equilibria of Interconnected Balloons", Quarterly Journal of Mechanics and Applied Mathematics , 35 (3): 419–440, doi : 10.1093/qjmam/35.3.419

^ Verron, E.; Marckmann, G. (2003), "Numerical analysis of rubber balloons" (PDF) , Thin-Walled Structures , 41 (8): 731–746, doi : 10.1016/S0263-8231(03)00023-5 , archived from the original (PDF) on 2012-04-02

^ Levin, Y.; de Silveira, F. L. (2003), "Two rubber balloons: Phase diagram of air transfer", Physical Review E , 69 (5): 051108, Bibcode : 2004PhRvE..69e1108L , doi : 10.1103/PhysRevE.69.051108 , hdl : 10183/101610 , PMID 15244809

^ Gabrielson, R.; Edwards, K. (May 26, 2020), "Desperate Hospitals May Put Two Patients on One Ventilator. That's Risky." , Propublica

^ Tronstad, C.; Martinsen, T.; Olsen, M. (2020), "Splitting one ventilator for multiple patients -- a technical assessment", arXiv : 2003.12349 [ physics.med-ph ]


The two-balloon experiment is an experiment involving interconnected balloons . It is used in physics classes as a demonstration of elasticity .

Two identical balloons are inflated to different diameters and connected by means of a tube. The flow of air through the tube is controlled by a valve or clamp. The clamp is then released, allowing air to flow between the balloons. For many starting conditions, the smaller balloon then gets smaller and the balloon with the larger diameter inflates even more. This result is surprising, since most people assume that the two balloons will have equal sizes after exchanging air.

The behavior of the balloons in the two-balloon experiment was first explained theoretically by David Merritt and Fred Weinhaus in 1978. [1]

The key to understanding the behavior of the balloons is understanding how the pressure inside a balloon varies with the balloon's diameter. The simplest way to do this is to imagine that the balloon is made up of a large number of small rubber patches, and to analyze how the size of a patch is affected by the force acting on it. [1]

The Karan- Guth stress-strain relation [2] for a parallelepiped of ideal rubber can be written

Here, f i is the externally applied force in the i' th direction, L i is a linear dimension, k is Boltzmann's constant ,
K is a constant related to the number of possible network configurations of the sample, T is the absolute temperature ,
L i 0 is an unstretched dimension, p is the internal ( hydrostatic ) pressure , and V is the volume of the sample. Thus, the force consists of two parts: the first one (caused by the polymer network ) gives a tendency to contract, while the second gives a tendency to expand.

Suppose that the balloon is composed of many such interconnected patches, which deform in a similar way as the balloon expands. [1] Because rubber strongly resists volume changes, [3] the volume V can be considered constant. This allows the stress-strain relation to be written

where λ i =L i /L i 0 is the relative extension. In the case of a thin-walled spherical shell, all the force which acts to stretch the rubber is directed tangentially to the surface. The radial force (i.e., the force acting to compress the shell wall) can therefore be set equal to zero, so that

where t 0 and t refer to the initial and final thicknesses, respectively. For a balloon of radius



r


{\displaystyle r}

, a fixed volume of rubber means that r 2 t is constant, or equivalently

and the radial force equation becomes

The equation for the tangential force f t (where L t



∝


{\displaystyle \propto }

r ) then becomes

Integrating the internal air pressure over one hemisphere of the balloon then gives

where r 0 is the balloon's uninflated radius.

This equation is plotted in the figure at left. The internal pressure P reaches a maximum for

and drops to zero as r increases. This behavior is well known to anyone who has blown up a balloon: a large force is required at the start, but after the balloon expands (to a radius larger than r p ), less force is needed for continued inflation.

When both balloons are initially inflated to the peak pressure, spontaneous symmetry breaking will occur, since the pressure in both balloons will drop when some air flows from one balloon into the other.

When the valve is released, air will flow from the balloon at higher pressure to the balloon at lower pressure. The lower pressure balloon will expand. Figure 2 (above left) shows a typical initial configuration: the smaller balloon has the higher pressure. So, when the valve is opened, the smaller balloon pushes air into the larger balloon. It becomes smaller, and the larger balloon becomes larger. The air flow ceases when the two balloons have equal pressure, with one on the left branch of the pressure curve ( r < r p ) and one on the right branch ( r > r p ).

Equilibria are also possible in which both balloons have the same size. If the total quantity of air in both balloons is less than N p , defined as the number of molecules in both balloons if they both sit at the peak of the pressure curve, then both balloons settle down to the left of the pressure peak with the same radius, r < r p . On the other hand, if the total number of molecules exceeds N p , the only possible equilibrium state is the one described above, with one balloon on the left of the peak and one on the right. Equilibria in which both balloons are on the right of the pressure peak also exist but are unstable. [4] This is easy to verify by squeezing the air back and forth between two interconnected balloons.

At large extensions, the pressure inside a natural rubber balloon once again goes up. This is due to a number of physical effects that were ignored in the James/Guth theory: crystallization , imperfect flexibility of the molecular chains, steric hindrances and the like. [5] As a result, if the two balloons are initially very extended, other outcomes of the two-balloon experiment are possible, [1] and this makes the behavior of rubber balloons more complex than, say, interconnected soap bubbles . [4] In addition, natural rubber exhibits hysteresis : the pressure depends not just on the balloon diameter, but also on the manner in which inflation took place and on the initial direction of change. For instance, the pressure during inflation is always greater than the pressure during subsequent deflation at a given radius. One consequence is that equilibrium will generally be obtained with a lesser change in diameter than would have occurred in the ideal case. [1] The system has been modeled by a number of authors, [6] [7] for example to produce phase diagrams [8] specifying under what conditions the small balloon can inflate the larger, or the other way round.

Due to a shortage of ventilators during the COVID-19 pandemic , it has been proposed that one ventilator could be shared between two patients. [9]
However Tronstad et al. [10] found that when the two sets of lungs had very different elasticities or airway resistance, there could be large discrepancies in the amount of air delivered. They argued that this might be seen as an example of the two-balloon experiment, with the two sets of lungs playing the role of the two balloons: "The 'two-balloon effect' (Merritt and Weinhaus 1978) could possibly have contributed to this volume discrepancy, and the inclusion of one-way valves could possibly help."



Was this page helpful?
Yes
No

The owner of this website (www.pipesandcigars.com) has banned the country or region your IP address is in (RU) from accessing this website.

Cloudflare Ray ID: 73c396471a55162e
•

Your IP:
Click to reveal
45.84.177.193
•

Performance & security by Cloudflare



En poursuivant votre navigation sur ce site, vous acceptez l'utilisation de cookies Accepter plus d'information
LIVRAISON GRATUITE A PARTIR DE 150 €
SATISFAIT OU REMBOURSÉ SOUS 7 JOURS
Blister de 10 Bougies + 10 Chiffres avec Socle en Plastique
Bougie Anniversaire Captain América
Bougie Anniversaire Chiffre Arc en ciel Paillettes
Bougie Anniversaire Chiffre Gold ombre
Bougie Anniversaire Chiffre Rainbow ombre
Bougie Anniversaire Nombre Arc en Ciel
Bougie Or avec Bobèche - Blister de 10
© Ballons à GoGo 2022 Tous droits réservés - v6
Articles de fête : qualité, originalité, inventivité
Vous souhaitez fêter un anniversaire , célébrer un mariage , offrir un réveillon du Jour de l'An original à vos proches et à vos amis ? Vous trouverez sur ballons-a-gogo.com un large choix d' articles de fête de grande qualité qui vous permettront de créer des animations originales et des décors surprenants à moindre frais. Notre site vous propose des guirlandes , des fanions , des lanternes chinoises ou des lampions colorés pour orner vos salles lors de fêtes thématiques, mais aussi de très originales figurines gonflables. Vous trouverez aussi des assortiments de feux d'artifice pour illuminer vos ciels d'été ou encore des machines à fumée ou à bulles de savon pour produire de très beaux effets spéciaux. Et à côté des nombreux cotillons , les farces et attrapes suffiront à créer l'ambiance un soir de réveillon ou pour une soirée d' Halloween . 
Légers, colorés, pas chers et ayant tout le charme des décorations à l'ancienne, les lampions ballons ou les lampions cylindriques décorent joliment une grande salle de fêtes comme un petit salon. Ballons-a-gogo vous propose un large éventail de lampions en papier aux coloris inédits ou déclinés dans des ors et des teintes métallisées pour Noël ou le Jour de l'An . Pour Halloween , optez donc pour des lampions citrouilles, pour le 14 juillet , arborez des lampons tricolores, que vous illuminerez de bougies spéciales ou de porte-lampions électriques à piles, sûrs et innovants. Pour le Nouvel An ou pour un mariage , Ballons-a-gogo vous propose un large choix de lanternes japonaises, raffinées et harmonieuses, ainsi que des lanternes volante s réalisées en papier ininflammable et biodégradable. Connaissez-vous cette tradition millénaire des lanternes volantes ? Dans les pays asiatiques, l'on envoie haut dans le ciel une lanterne volante en faisant un vœu : plus la lanterne s'envole haut, plus le vœu a de chance d'être exaucé. Une autre idée simple et originale pour vos fêtes à thèmes , les fanions en papier ou en plastique avec leurs nombreuses thématiques : anniversaire , ballons de football, disco, rentrée des classes, fête de la musique ou fête du vin , casino ou VIP. Vous trouverez également des guirlandes aux couleurs de nombreux pays et des drapeaux pour fêter une Coupe du monde ou un grand événement sportif : cocardes en crépon, petits drapeaux en plastique, drapeaux en tissu ou grands drapeaux de façade. Pour des rires partagés, à vous les cotillons , serpentins , confettis , trompettes et sans-gêne, mais aussi les farces et attrapes, faux sang en spray, dés pipés, encre infernale, dentiers sauteurs ou faux doigts bandés, tandis que les piñatas en paille et papier mâché colorés réjouiront les petits lors des fêtes d'anniversaire . Si vous désirez distinguer vos événements de tous les autres, découvrez, enfin, les animations haut de gamme proposées par notre site. Osez donc les effets spéciaux dans votre jardin avec nos machines à bulle, nos machines à fumée ou encore nos stroboscopes à led qui vous permettront de créer des effets spéciaux de grand charme, féeriques et optiques. Quant aux feux d'artifice , ils susciteront l'émerveillement dans les ciels de vos jardins, avec leurs couleurs flamboyantes et la forme graphique de leurs comètes, retombant en paillettes, en pivoines, en saules pleureurs ou en boules de neige !
Petits goûters d'anniversaire ou grandes cérémonies de mariage seront les plus réussis grâce à ces articles de fête originaux et tendance qui créeront le rire, la surprise ou l'émerveillement. Commandez vite sur ballons-a-gogo.com ces accessoires haut de gamme proposés au meilleur rapport qualité/prix !

BALLONS-A-GOGO.COM, LEADER EN LIGNE DE LA DÉCORATION DE BALLONS


Depuis plus de 25 ans, Ballons-a-gogo est l'entreprise leader dans la décoration de ballons. Concepteurs et décorateurs, nous réalisons des décorations éphémères d'une grande originalité. Car le ballon, léger, coloré et multiforme, permet de créer de très nombreux décors et d'habiller à peu de frais de grands volumes. Grandes entreprises, collectivités et particuliers nous font confiance depuis des années pour décorer des centres commerciaux, habiller des salles de réception, réaliser des décors à thèmes, Colorer des vitrines et des boutiques.


Retrouvez sur notre site nos ballons en latex 100% biodégradable ou en aluminium premium, d'origine américaine, modèles haut de gamme, ballons holographiques à la haute brillance, modèles en plastique bubble qui offrent de très beaux jeux de transparence. Notre palette est très étendue et c'est en décorateurs confirmés que nous vous offrons des coloris tendance et des effets de matière que vous ne trouverez pas ailleurs, teintes perlées pastel, couleurs néon, effets cristal ou pierre d'agate. 


En quelques clics, découvrez un choix inégalé de ballons à thème pour Halloween, Noël, le Jour de l'An, Pâques, la Saint-Valentin ou la Saint-Patrick. Des modèles aux mille et une formes vous permettront de créer des ambiances Disco, Casino, Hollywood, Hawaï, de fêter le printemps ou de célébrer l'arrivée de l'été !


Pour fêter vos proches ou célébrer des événements heureux, ballons-a-gogo.com vous propose également des ballons personnalisables sur lesquels vous pourrez écrire des messages d'amour, à l'occasion d'un mariage ou d'une naissance. Les enfants ne sont pas oubliés et les ballons d'anniversaire offrent un large choix de formes et de matières, des princesses aux pirates. Ils retrouveront également leurs héros Disney ou Marvel préférés. 


Vous recherchez une décoration facile à mettre en place et pas chère, mais qui se distingue par son originalité ? Commandez en toute confiance sur ballons-a-gogo.com et bénéficiez d'une qualité irréprochable, de prix réduits et d'un savoir-faire d'experts en matière de décoration.


Grâce à Ballons à gogo, mettez de couleur dans vos espaces.


Welcome To KING's Pipe Online Headshop

Technological advancement has helped the dabbing industry by introducing the e-Nail. Science has given us the ability to control heat when dabbing unlike in the old days with torches. With torches, there is always the risk of overheating or burning then eventually wasting your materials. With the e-Nail, materials are evenly heated to your preferred level of temperature producing the most potent and flavorful vapor.
$20 OFF Orders $130+ w/ Code: KP20 | FREE SHIPPING

Add your deal, information or promotional text
By clicking Enter, you verify that you are 21 years of age or older.
You will have ANOTHER Age Verification at Checkout
Our online headshop features an extensive selection including pipes, bongs, vaporizers, and discount smoking accessories
Since its inception in 2014, KING’s Pipe has been established as the best online pipe shop around. Based in Southern California, we sell a wide variety of quality smoking gear from top US brands, including vaporizers , dab rigs , recyclers , bubblers , glass pipes , and bongs online.
We’re committed to providing our amazing customers with the best possible customer service, coupled with discreet and free shipping , no restocking fee for returns, and a candy shop of unique and authentic toke tools!
If you need any help or suggestions, KING's Pipe would love to hear from you. Shoot us an email on our contact page , and we'll respond within our business hours of Monday–Friday from 10 AM to 4 PM PST. We hope you love our online pipe shop! Happy smoking!
As one of the most well-recognized online smoke shops, we pride ourselves on our brand integrity. All of our items are tested to ensure optimal performance, and we’ve spent years developing long-lasting relationships with top American manufacturers such as Empire Glassworks , AMG , and Yocan . Because our pipe shop is an authorized online seller for these brands, you’re covered even if your pipe, bong, bubbler, rig, or vape is defective.
For those on a tight budget, KING’s Pipe also carries inexpensive, imported bongs and dab rigs — including gas mask bongs online.
Each order is discreetly packaged with a typical turnaround time of 24-48 hours, and we’re happy to offer free shipping on all US orders (including Hawaii and Alaska!). If you’re not satisfied with your purchase, we offer no-hassle returns on unused items up to 14 days after the date of delivery.
Our online headshop uses secure checkout with SSL, the highest level of security certification available. Not only does this make credit card payments safe with our pipe shop — it also establishes an encrypted connection between our customers and our servers to protect sensitive data. For KING’s Pipe customers who prefer to pay in installments, we accept Sezzle and ViaBill .
Who says April is the only time to celebrate 420? Why not appreciate the beauty of all things smoking all year long!
If you have a smoker in your life you’re shopping for this holiday season, you’ve come to the right place. KING’s Pipe Online Headshop is your go-to, one-stop-shop for all the stoner gifts you need.
This blog contains the most basic and simplest definition, comparisons, and our own compilation of the top and best selling dab pens and wax pens. You will not go wrong with any of these devices created and innovated by the tops brand manufacturers in the industry from all over the globe.
Sign up for our newsletter for access to exclusive online headshop discounts, new product updates, and 10% off your next purchase.

La sélection allemande de Felix #11
Une blonde mignonne avec de gros seins
Baise anale avec la jeune Mary Jane Johnson