baber/WOPTO huggingface dataset:
Patent EP-0001284-A1 (EP)
Inventor: LAI JOHN TA-YUAN
IPC: C08L33/00
Filed: 1978-09-20
Abstract: Novel polysubstituted 2-keto-1,4- diazacycloalkanes are powerful stabilizers for materials subject to ultraviolet (UV) light degradation, particularly for polyolefins. The cyclic 2-keto compounds of this invention have (a) a fixed two-carbon bridge between the N'and N 4  atoms of the diaza ring, the remaining portion of the ring having a variable length bridge of two or more carbon atoms, (b) an N-adjacent carbonyl in the fixed two-carbon bridge, and (c) at least one N 4 -adjacent carbon atom of the diaza ring is polysubstituted, that is, has two substituents which may be cyclizable. 
     Compositions containing (a) the polysubstituted 2- keto-1,4- diazacycloalkanes of this invention, and (b) prior art polysubstituted 2-keto-1,4- diazacycloalkanes, exhibit excellent stability to UV light.
Patent EP-0001763-A1 (EP)
Inventor: MALBURG WERNER
IPC: F24S10/55
Filed: 1978-10-10
Abstract: A flat collector for collecting sunlight has an inner space filled with a heat transfer medium. It constitutes a panel (10) made of transparent material provided with inlets and outlets (17, 18), the inner space being designed as a flow channel (11). The heat transfer medium (12) is a liquid with suspended dusts (13), so that the sunlight is absorbed in the liquid. In order to prevent the dusts settling, the flow channel (11) is equipped with turbulators (16). <IMAGE>
Patent EP-0002934-A1 (EP)
Inventor: BRAUKMANN HEINZ WERNER
IPC: G05D23/02
Filed: 1978-12-20
Abstract: A thermostatic control valve has a built-in temperature sensor (58) actuating a valve mechanism (20) to regulate flow of heated fluid through a conduit (14). The valve (10) has a housing (36) open at one end and securable to the conduit (14) at the other end. The sensor (58) is secured in the open end of the housing (36) and is responsive to changes in temperature of the air in the open end of the housing (36), the sensor (58) acting on a plunger (68) which in turn acts on the valve mechanism (20) at the other end of the housing to regulate fluid flow through the conduit (14). 
     Thermal shielding means (50, 70, 72) are provided in the housing (36) between the sensor (58) and the valve mechanism (20) to substantially prevent heat from the valve mechanism (20) affecting the sensor (58), and vents (46) are provided in the housing (36) below the thermal shielding means (50, 70, 72) to allow air heated by the valve mechanism (20) to escape to atmosphere.
Patent EP-0008058-A1 (EP)
Inventor: KINAST GUNTHER DR
IPC: C07D211/98
Filed: 1979-07-30
Abstract: Verbindungen der Formel <IMAGE> worin R1 Wasserstoff, R5, Formyl, COR5, CO2R5, Carbonamid, CONHR5, CONR5R6, CSR5, CSNH2, CSNHR5, CSNR5R6, SO3H oder SO2R5, R2 Wasserstoff oder R5 oder R1 und R2 gemeinsam die Grupierung <IMAGE> R3 Wasserstoff, Hydroxy, OR5, Mercapto, SR5, Amino, NHR5, NR5R6, Cyano, Carboxy, CO2R5, Carbonamido, CONHR5, CONHR5R6, Aminomethyl, CH2NHR5, CH2NR5R6, CH2NHR5, CH2NR5COR6, CH2NHSO2R5, CH2NR5CO2R6 Sulfo, Hydroxymethyl, CH2OR5 oder CH2OCOR5, R4 WASSERSTOFF, R5, Hydroxymethyl, CH2OR5, CHR5OH, CHR5OR6, CR5R6OH, CR5R6OR7, Formyl, CR5O, Carboxy, CO2R5, Carbonamido, CONHR5, CONR5R6 oder CH2X, R5, R6 und R7 unabhängig voneinander einen gegebenenfalls substituierten, geradkettigen, verzwegten oder cyclischen gesättigten oder ungesättigten aliphatischen Kohlenwasserstoffrest oder einen gegebenenfalls substituierten aromatischen oder heterocyclischen Rest, wobei 2 Reste R5, R6 und R7 auch miteinander verknüpft sein können, R8 und R9 unabhängig voneinander Wasserstoff oder R5 bedeuten, eignen sich als Glykosidhydrolase-Inhibitoren zur Therapie von Prädiabetes, Gastritis, Obstipation, Meterorismus, Flatulenz, gastrointestinalen Infektionen, Hypertension, Karies, Atherosklerose und besonders Adipositas, Diabetes und Hyperlipoproteinämie und auch als Zusätze zu Tierfuttermitteln. Es werden mehrere Verfahren zur Herstellung der neuen Verbindungen angeführt.
Patent EP-0009157-A1 (EP)
Inventor: EHRSAM RUEDI
IPC: E04B2/88
Filed: 1979-09-01
Abstract: 1. Pressure relieving facade for buildings endangered by sudden pressure differences consisting of tabular wall element (1) which are attached by holding means along their border areas (1a) on the side facing the building in such a way that they detach themselves at a given internal pressure, characterized in that the tabular wall elements (1), preferably the portions of parapets which lie below the windows, are provided with a circumferential holding piece (5) arranged vertically to the facade plane along their border area (1a) on the side facing the building, the free end of which piece goes over into a thickened clamping ledge (7) which is pushed into an undercut clamping slot (8) of a profile (9) of synthetic material fixed to the facade and is hels there detachably in an elastic form-lock.
Patent EP-0009173-A1 (EP)
Inventor: MOLLS HANS-HEINZ DR
IPC: C09B67/00
Filed: 1979-09-05
Abstract: In einem Trockner werden Verteilerkörper von einer zentralen Drehvorrichtung (2) durch eine Zwangsführung zwischen zueinander parallelen Ebenen (8, 9), die aber nicht senkrecht zur Drehvorrichtungsachse liegen, so bewegt, daß die gesamte Wärmeaustauschfläche des Trockners von den Verteilerkörperkanten überstrichen wird. Dadurch ist eine Selbstreinigung der inneren Oberfläche des Trockners gewährleistet, und es tritt bei zu Klumpen neigenden Produkten eine zusätzliche Mahlung auf. Bevorzugt sind als Verteilerkörper gerade Kreiszylinder; sie sind ohne zusätzliche Führung mit geringem axialem Spiel zwischen den parallelen Ebenen frei beweglich.
Patent EP-0007669-A1 (EP)
Inventor: JENNER MICHAEL DAVID
IPC: H01L31/0264
Filed: 1979-07-17
Abstract: In the manufacture of an infra-red radiation detector element (51) a body of infra-red sensitive material (e.g. cadmium mercury telluride) secured to a substrate (22) is subjected to ion-etching to remove part of the material over the whole thickness of the element (51) at areas (56) between the contact areas of the element electrodes (35 and 36b) so as to define a current path between these electrodes (35 and 36b) which extends through the remaining material and is longer than the distance along a straight line between the electrodes (35 and 36b). This longer current path increases the charge-carrier transit time and resistance between the electrodes (35 and 36b) so that the responsivity of the detector element (51) can be improved while still producing a compact element structure because of the advantages of defining the current path by ion-etching. This etch-removal may involve forming parallel slots (56) which extend from opposite side walls of the element (51) to define a meandering current path, and may additionally be used to form a mutual separation (55) between portions (51 and 52) of the body each of which is to form a separate infra-red detector element of an array formed on the substrate (22). 
<??>It is suggested that Figure 16 should accompany the abstract when published.
Patent EP-0007170-A1 (EP)
Inventor: TAYLOR CHARLES JEFFERSON
IPC: A61K8/19
Filed: 1979-06-04
Abstract: The tendency of gel toothpastes comprising silica thickeners, such as silica aerogel or precipitated silica, and a fluoride source, such as sodium monofluorophosphate or fluoride, to corrode aluminium tubes can be reduced by incorporating at least 0.01 % by weight sodium or potassium hydroxide or carbonate, so that the pH of the toothpaste is at least 8.5.
Patent EP-0013950-A1 (EP)
Inventor: CHIVARI ILIE
IPC: F16D3/04
Filed: 1980-01-18
Abstract: A first connecting link (22) is jointed in a swivelling manner to a first coupling half (10) at (24). A second connecting link (34) is jointed in a swivelling manner to a second coupling half (12) at (36). A first double control lever (38) is connected via a first control lever (40) to the first coupling half (10) and via a second control lever (42) to the second coupling half (12) as well as via a third control lever (48) to the first connecting link (22) and via a fourth control lever (50) to the second connecting link (34). A second double control lever (52) is arranged on the opposite side and is connected via a fifth control lever (54) to the first coupling half (10) and via a sixth control lever (56) to the second coupling half (12) as well as via a seventh control lever (62) to the first connecting link (22) and via an eighth control lever (64) to the second connecting link (34). <IMAGE>
Patent EP-0015518-A1 (EP)
Inventor: MIHARA YUJI C O FUJI PHOTO FIL
IPC: G01N33/536
Filed: 1980-02-29
Abstract: In a method for the immunological analysis of trace components by marking or labelling an antigen or antibody with a marker, an immune reaction is caused using an antigen or antibody marked with a fogging agent for silver halide, the labelled antigen or antibody is separated from the labelled antigen-antibody reaction product, the silver halide is developed in the presence of either one of the labelled antigen or antibody and the labelled antigen-antibody reaction product, and the density obtained is measured. 
     The method is comparable to radioimmunoassay in having high reproductibility and sufficient sensitivity but does not involve any risk due to radiation.
Patent EP-0028051-A1 (EP)
Inventor: D ADDIECO ALFRED ANTHONY
IPC: H01B1/16
Filed: 1980-10-28
Abstract: Air fireable nickel boride-based end termination compositions for multilayer capacitors are provided. The nickel boride compounds utilized are either (Ni 3 B) a (Ni 3 Si) b  or Ni 3 B 1-x P x  and the compositions also contain a glass whose component oxides have a redox potential of less than -0.5 volt. These compositions, upon firing, afford conductors such as end terminations in multilayer capacitors having excellent solderability and solder leach resistance, adhesion to dielectric substrates and electrical properties substantially equivalent to standard silver/palladium conductors.
Patent EP-0021641-A1 (EP)
Inventor: LEVITT GEORGE
Filed: 1980-06-03
Abstract: An improved process for preparing arylsulfonyl isocyanates by phosgenation of arylsulfonamides inthe presence of a catalytic quantity of a hydrocarbyl isocyanate and a catalytic quantity of atertiary amine base. The sulfonyl isocyanates are useful intermediates.
Patent EP-0027020-A1 (EP)
Inventor: HOWE ROBERT KENNETH
IPC: A01N43/76
Filed: 1980-09-29
Abstract: Compounds of the formula (I) 
<CHEM>
 wherein R is hydrogen, alkyl containing 1 to 5 carbon atoms, halo alkyl containing 1 to 5 carbon atoms or agriculturally acceptable cations; R1 is alkyl containing 1 to 5 carbon atoms or polyhaloalkyl containing 1 to 5 carbon atoms; R2 is alkoxy containing 1 to 5 carbon atoms, halogen, or phenoxy. 
<??>A method for reducing injury to crop plants due to applicition thereto of thiocarbamate or acetanilide hericides which comprises applying to the plant locus a safening effective amount of a compound having the formula (I),
 wherein R2 can also be hydrogen.
Patent EP-0015229-A1 (EP)
Inventor: KARR DIETER E DIPL-PHYS
IPC: A61N1/04
Filed: 1980-02-21
Abstract: 1. Electrode for an artificial heart pace-marker for transvenous use with at least one attaching element (6, 7, 13), which is arranged on a plunger (5), which is guided in a hollow cylinder (1) connected to a lead-in coil (2), so that for the insertion of the electrode the attaching element may be slid so far into the hollow cylinder that it does not come into contact with the cardiac tissue, and for fixing the electrode the attaching element may be slid out beyond the front surface there of by a force exerted by a guide tool (11) which extends within the lead-in coil, characterized in that, the attaching element (6, 7, 13) has at least one pointed end directed substantially tangentially, which may be brought into engagement with the cardiac tissue by a twist exerted on the attaching element, that, for exerting the twist via the guide tool (11) with the inclusion of the plunger (5, 5') or via the lead-in coil, there are provided at the rear end of the plunger coupling means (12, 12') which can be brought into turning contact with the guide tool and/or means (8, 9) for the transmission of the twist from the hollow cylinder (1, 1') connected to the lead-in coil to the attaching element, and that the plunger lying against the interior surface of the hollow cylinder (1, 1') forms a seal against body fluid leaking into the interior of the lead-in coil, at least in the extended position of the attaching element.
Patent EP-0020706-A1 (EP)
Title: Composition de lecithine soluble dans l'eau
Inventor: KASS GUS S
IPC: A61Q5/02
Filed: 1980-06-17
Abstract: Une methode d'amelioration de la solubilite de la lecithine comprend plusieurs etapes dont celle qui consiste a melanger la lecithine avec un agent solubilisant selectionne parmi le groupe constitue d'oxydes d'amines tertiaires, de sulfates d'alkyles alcooliques, de betaiines d'alkylamidopropyle, de sulfonates-sulphonates d'alcene, de sulfoacetates d'alkyle et de sel disodique de monoalkyle amides de sulfosuccinate. La lecithine est rendue extremement soluble dans l'eau et soluble dans des quantites limitees d'ethanol aqueux.
Patent EP-0035201-A1 (EP)
Inventor: RIECK HANS-PETER DR
IPC: C01B25/10
Filed: 1981-02-23
Abstract: Die Erfindung betrifft ein Verfahren zur Herstellung von Phosphorpentachlorid hoher Reinheit in Form eines rieselfähigen Kristallpulvers durch Umsetzung von Phosphortrichlorid mit Chlor. Die Umsetzung wird in zwei Stufen vorgenommen. In der ersten Stufe wird unter Rühren bei einer Temperatur von 0 bis 150°C Phosphortrichlorid mit der 0,7 bis 0,999fachen molaren Menge Chlor vereinigt und dabei zu einem aus Phosphorpentachlorid und Phosphortrichlorid bestehenden Kristallbrei umgesetzt. Diesen Brei läßt man in der zweiten Stufe bei 0 bis 150°C mit einem Überschuß an Chlor zu Phosphorpentachlorid reagieren.
Patent EP-0036558-A1 (EP)
Inventor: WAGNER GEBHARD DR
IPC: C03C8/02
Filed: 1981-03-10
Abstract: A coated metal article with continuous surface and a method of manufacturing the same are described, in which the coating consists of a first layer made of a cermet and a second, chemically resistant and corrosion-resistant silicate glaze.
Patent EP-0037587-A1 (EP)
Inventor: HAGIWARA TARO
IPC: B62D25/20
Filed: 1981-04-08
Abstract: A vehicle body comprises a sill (30) along a lateral end of a floor panel (32) forming a lower side of a door opening. The sill is an open section, one piece member having an opening (60) extending throughout the length thereof. A cover (62) of a plastic material is removably attached to the sill in a mannerto define a closed sill configuration.
Patent EP-0043924-A1 (EP)
Inventor: FUCHS HUGO DR
IPC: C07D201/16
Filed: 1981-06-15
Abstract: Verfahren zur kontinuierlichen Extraktion von Caprolactam aus solches und dessen Oligomere enthaltenden wäßrigen Lösungen mit organischen Lösungsmitteln, wobei man im oberen Teil einer Extraktionszone eine Caprolactam und dessen Oligomere enthaltende wäßrige Lösung und im unteren Teil organische Lösungsmittel zuführt, am oberen Ende eine Lösung von Caprolactam in organischen Lösungsmitteln und am unteren Ende eine Oligomere des Caprolactams enthaltende wäßrige Phase abführt, wobei man flüssige aromatische Kohlenwasserstoffe verwendet und die Extraktion bei einem pH-Wert von 2,0 bis 6,0 durchführt.
Patent EP-0043553-A1 (EP)
Inventor: PETERSEN KLAUS DIPL-ING
IPC: G21C1/12
Filed: 1981-07-01
Abstract: Bei einem Nachwärmeabfuhrsystem für einen gasgekühlten Kugelhaufenreaktor, dessen von kugelförmigen Brennelementen unter Einwirkung der Schwerkraft durchsetztes und vom Kühlgas durchströmtes Reaktorcore (1) von einem den Kugelhaufen umschliessenden Seitenreflektor (13) umgeben ist, der sich zwischen Kühlgaseintritt (15) und Kühlgasaustritt (17) des Reaktorcores erstreckt, ist am Seitenreflektor (13) in dessen den Kugelhaufen (1a) umgebenden Bereich mit Abstand vom Kühlgaseintritt (15) und Kühlgasaustritt (17) eine Absaugleitung (12) für Kühlgas angeschlossen, die zu einem oder mehreren Nachwärmekühlern (10, 10a, 100b) geführt ist. Zur Rückführung des aus dem Raktorcore (1) abgezogenen Kühlgases mündet eine mit dem oder den Nachwärmekühlern (10, 10a, 10b) verbundene Kühlgasrückführleitung (19) am Kühlgaseintritt (15) des Reaktorcores (1).
Patent EP-0047502-A1 (EP)
Inventor: KOLB WALTER
IPC: A01D34/74
Filed: 1981-09-03
Abstract: 1. A cutting height adjustment device for lawn-mowers having wheel carriers (14) which can be vertically adjusted relative to the chassis (1) and locked in different vertical positions, and a release knob (2) for the wheel carriers (14) which can be actuated from the upper side of the mower and which automatically returns into the locked position, characterised in that a handgrip (3) is provided in the chassis adjacent to the release knob (2), with the handgrip (3) being arranged adjacent the release knob (2) in such a way that the latter can be actuated with the thumb while the remaining fingers of the hand engage the handgrip (3).
Patent EP-0049372-A1 (EP)
Inventor: FRIESE KARL-HERMANN DR DIPL-PH
IPC: H01T21/02
Filed: 1981-09-04
Abstract: Es wird eine Zündkerze (10) für Brennkraftmaschinen vorgeschlagen, die anstelle einer metallischen Mittelelektrode eine Mittelelektrode (23) aufweist, welche aus einem mit einer elektrisch leitfähigen Schicht (31) überzogenen, elektrisch nicht leitenden Stift (23/1) besteht; der Stift (23/1) ist vorzugsweise spaltfrei in den zündseitigen Endabschnitt der Isolierkörper-Längsbohrung (21) eingebaut und besteht aus einem Material, dessen Schwindungsverhalten und Wärmeausdehnungskoeffizient im wesentlichen dem des Isolierkörpermaterials aufweist. Vorzugsweise wird für den Stift ebenfalls Isolierkörpermaterial verwendet. Als elektrisch leitfähige Schicht findet bevorzugt ein Metall-Keramik-Gemisch Anwendung, sie kann zusätzlich noch als Widerstandselement und/oder Vorfunkenstrecke ausgebildet sein. Die beanspruchte Zündkerze kann gemäß einer weiteren Ausführungsform auch als Gleitfunken-Zündkerze gestaltet sein.
Patent EP-0049923-A1 (EP)
Inventor: VAN DOREN HENDRIK DIRK
IPC: B65G47/88
Filed: 1981-10-02
Abstract: O The invention relates to a device for the further conveyance of each one of a row of cylindrical objects (14) along a path (11) shaped in the form of an arc of a circle by means of a rotatable driving member. 
     The device according to the invention is characterized in that the driving member is formed by a cam disc (35), the peripheral surface (34) of which comprises at least one at least partially spiral-shaped part (19,20).
Patent EP-0035836-A1 (EP)
Inventor: CHU CHIN CHIUN
IPC: C01B39/42
Filed: 1981-02-19
Abstract: A process for the conversion of aromatic compounds to dialkylbenzene compounds rich in the 1,4-dialkylbenzene isomer. The reaction is carried out in the presence of a particu- lartype of zeolite catalyst having a silica to alumina mole ratio of at least 12 and a constraint index of about 1-12, said catalyst having been modified by treatment with compounds of the alkaline-earth metals (Ca, Sr, Ba), and optionally phosphorus, to deposit a minor proportion of such elements on the zeolite.
Patent EP-0039644-A1 (EP)
Title: Dispositif d'anti-dévirage pour arbre de pompe
Inventor: FALBIERSKI JEAN-JACQUES
IPC: F04B49/10
Filed: 1981-05-05
Abstract: La présente invention concerne les dispositifs d'anti-dévirage pour arbre de pompe et, plus précisément, les dispositifs comprenant un galet asymétrique (3) pivotant autour d'un axe fixe (4) et un moyen élastique (5) engendrant une force de rappel tendant à appliquer le galet (3) contre la périphérie de l'arbre (1) de la pompe. Selon l'invention, le dispositif d'anti-dévirage comprend, en outre, au moins une ailette (7) solidaire du galet (3), disposée sensiblement perpendiculairement à la direction du fluide pompé pour que le mouvement de ce dernier engendre une force qui, appliquée à cette ailette, présente un moment par rapport à l'axe du galet, légèrement supérieur à celui de la force de rappel et de sens opposé. Application aux pompes nucléaires.
Patent EP-0059909-A1 (EP)
Inventor: HAHN ERWIN DR
IPC: C14C1/08
Filed: 1982-02-27
Abstract: Conventionally limed hides are delimed for from one to six hours under conventional deliming conditions in respect of liquor length, temperature and pH of the liquor, by a process in which a cyclic carbonate of a polyhydric aliphatic alcohol of 2 to 6 carbon atoms is employed as the active agent.
Patent EP-0062254-A1 (EP)
Inventor: KUYAMA SHINPEI
IPC: A01N43/76
Filed: 1982-03-26
Abstract: Die Erfindung betrifft neue substituierte Acetanilide der allgemeinen Formel <IMAGE> worin X für Sauerstoff oder Schwefel, Y für C1-4-Alkylthio und R für C1-4-Alkyl steht, ein Verfahren zu ihrer Herstellung und ihre Verwendung als Herbizide.
Patent EP-0066211-A1 (EP)
Inventor: ALLEN GARY F
IPC: C07B61/00
Filed: 1982-05-21
Abstract: Die vorliegende Erfindung betrifft ein verbessertes Verfahren zur katalytischen Hydrierung von Di-(4-aminophenyl)-methan zu flüssigem, 15 bis 40 Gew.-% und vorzugsweise 18,5 bis 23,5 Gew.-% des Trans, trans-Isomeren enthaltenden Di-(4-aminocyclohexyl)methan. Die Erfindung beruht auf der Verwendung eines trägerfreien Ruthenium-Katalysators unter speziellen Verfahrensbedingungen. Während der Hydrierungs-Reaktion müssen ein Wasserstoff-Druck von mindestens 172, 4 bar (2 500 psi) und eine Temperatur von 150°C bis 210°C eingehalten werden.
Patent EP-0080720-A1 (EP)
Inventor: GRANT THOMAS STANLEY
IPC: C08L51/04
Filed: 1982-11-29
Abstract: Styrenic resins having incorporated therein from 0.5 to 15 pbw of a copolymerizable, ethlenically unsaturated carbonamide such as acrylamide form alloys with polyamides which exhibit improved compatibility, higher heat distortion temperatures and improved Izod impact values over the range of from 5 to 95 wt.% polyamide and 95 to 5 wt.% modified styrenic resin. The alloys may further include unmodified styrenic resins, as well as conventional stabiiiz- ers, fillers and the like.
Patent EP-0083063-A1 (EP)
Inventor: BEUTLER HELMUT DR
IPC: D06B3/18
Filed: 1982-12-21
Abstract: In the wet treatment of fibre cables, for example dyeing in the gelled state, it is very difficult, especially with a total titre of more than 1,000,000 dtex, to obtain a uniform penetration and action of the liquor over the entire cross-section of the fibre cable. In addition to the propagation of suitable dyestuffs and the colouring knowhow, therefore, the mastery of the mechanical technology of gel dyeing must be considered a precondition for a marketable quality of the dyed articles produced by this process. According to the invention, these problems are solved in that the spinning material running continuously through a wet-treatment zone is forced by the action of mechanical means to allow a loosening of its material structure, in order thereby to bring about transversely to the direction of advance of the article an intensive penetration of the fibre material by the treatment liquor. The change in state of the packing density which is decisive for such penetration is obtained by means of the fulling effect which, with a modification of the pressing force or bearing pressure in particular regions during the passage of the cable strand, is brought about by (a) a system of a plurality of pairs of pinching rollers rotated relative to one another in relation to their axial direction or (b) a system of a plurality of centrally and/or eccentrically rotating rollers of differing spatial arrangement. <IMAGE>
Patent EP-0057521-A1 (EP)
Inventor: JONES ALUN
IPC: G01N3/08
Filed: 1982-01-15
Abstract: This invention relates to a method of determining the average plastic strain ratio ( r ) of sheet material of known density. This is effected by computation utilising an empirical relationship existing for the material between  r  and an elastic property thereof, the elastic property being manifest as the velocity of mechanical vibrations propagated in the sheet.