baber/WOPTO huggingface dataset:
Patent IT-1250444-B (IT)
Title: Macchina automatica per calzare un tubolare protettivo su articoli in genere
Inventor: FEDELE ROSSI FRISON TATYANA
IPC: B65B/
Filed: 1991-07-03
Granted: 1995-04-07
Abstract: La macchina automatica per calzare un tubolare protettivo, vantaggiosamente a rete, su articoli in genere è essenzialmente caratterizzata dal fatto di prevedere una culla di ricevimento dell'articolo prevista mobile da una stazione di caricamento ad una stazione di accoppiamento, mezzi divaricatori in detta stazione di accoppiamento atti a divaricare la bocca del tubolare alimentato allo stato appiattito, organi di presa atti ad afferrare detta bocca divaricata ed a calzare detto tubolare su detto articolo, e mezzi di taglio di detto tubolare e eventuali mezzi di saldatura delle bocche di estremità dello spezzone di tubolare tagliato.
Patent IT-1255983-B (IT)
Title: Procedimento per la purificazione di un amminoacido usando una resina scambiatrice di ioni
Inventor: ITOH HISAO
IPC: B01J47/10
Filed: 1991-09-25
Granted: 1995-11-17
Abstract: Procedimento per la purificazione di un amminoacido che consiste nel porre a contatto una soluzione di un amminoacido contenente impurezze con una resina scambiatrice di ioni per adsorbire selettivamente l'amminoacido sulla resina, eluire e recuperare l'amminoacido adsorbito per cui la resina viene posta a contatto con la soluzione di amminoacido in stadi multipli continui in controcorrente durante l'adsorbimento e si pone a contatto un eluente con la resina adsorbita in stadi multipli continui in controcorrente, durante eluizione.
Patent IT-1258799-B (IT)
Title: Girante di ventilatore con un mozzo a forma di marmitta
Inventor: SCHEIDEL WOLFGANG
IPC: F04D29/32
Filed: 1992-01-21
Granted: 1996-02-29
Abstract: Viene proposta una girante di ventilatore con un mozzo a forma di marmitta servente a ventilare il dispositivo di raffreddamento per il motore endotermico di un autoveicolo. In corrispondenza della parete esterna della marmitta del mozzo è disposta una pluralità di alette estendentesi in sostanza radialmente e sul fondo della marmitta è fissato l'albero di indotto di un motore di azionamento elettrico, laddove il fondo della marmitta in corrispondenza del proprio lato interno presenta più nervature, reciprocamente distanziate, le quali si estendono radialmente fra le quali si ottengono campi del fondo della marmitta. Si ottiene una decisiva riduzione del rumore prodotto dal ventilatore quando il fondo a marmitta nell'ambito di questi campi presenta incavi che si dipartono dal suo lato interno ed hanno almeno una profondità pari al 70% dello spessore del fondo della marmitta.(Figura 1).
Patent IT-1260542-B (IT)
Title: Lamella di contatto per un guardiaordito elettrico
IPC: D03D51/30
Filed: 1992-06-04
Granted: 1996-04-09
Abstract: Per la chiusura sicura del circuito di corrente tra parte interna ed esterna di una sbarra di contatto in un guardiaordito elettrico si propone una lamella di contatto (1) con testa smussata (3), in cui il bordo interno (5) della testa (3) rivolto verso la fessura (7) per la sbarra di contatto della lamella (1) presenta almeno due tratti (5a, 5b), che sono smussati in modo differente.
Patent IT-1273779-B (IT)
Title: Method and apparatus for drying olive residues
Inventor: MORALES GARCIA ISIDORO
IPC: A23N12/08
Filed: 1994-02-16
Granted: 1997-07-10
Abstract: A method and an apparatus for the drying of olive residues, in which the residue moves from the corresponding extraction station through a drying pipe, is introduced into a steel tower 5 via an atomiser by the push exerted on the residue by a pump 2, assisted at the inlet of the atomiser by a compressor 1, the residue being introduced inside the tower where it is subjected to the action of fans 6, both the skin and the pulp emerging to the outside and being subjected to the action of a cyclone connected to the tower, the stones being collected in the lower portion of the tower. <IMAGE>
Patent IT-1269789-B (IT)
Title: Machine for shredding cardboard scraps
Inventor: LORENZONI REMO
IPC: B02C/
Filed: 1994-05-18
Granted: 1997-04-15
Abstract: Machine for shredding cardboard scraps, having in succession with the scrap collection funnel a series of circular blades, supported at a distance by an actuating shaft, the blades co-operate with a counterpressure roller, and in succession with the group consisting of circular blades there is provided a shaft which is outfitted in circumferential direction with knife blades, arranged in parallel with the lengthwise axis of the shaft and co-operating with an adjacent counterpressure roller.
Patent IT-1270249-B (IT)
Title: Dispositivo di trasmissione della coppia con almeno due masse volaniche ruotanti l'una rispetto all'altra
Inventor: REIK WOLFGANG
IPC: F16F15/12
Filed: 1994-06-17
Granted: 1997-04-29
Abstract: L'invenzione riguarda un dispositivo di trasmissione della coppia con almeno due masse volaniche ruotanti l'una rispetto all'altra mediante un supporto in contrasto con l'azione di un dispositivo di smorzamento con accumulatori di forza agenti nella direzione perimetrale, e di tali masse una - la prima - può essere collegata con l'albero condotto di un motore endotermico e l'altra - la seconda - con l'albero di comando di un riduttore mediante un giunto a frizione.
Patent IT-1258412-B (IT)
Title: Gioco di pazienza perfezionato.
IPC: A63F9/12
Filed: 1992-07-06
Granted: 1996-02-26
Abstract: L'invenzione si riferisce ad un gioco di pazienza del tipo in cui una pluralità di pedine viene spostata lungo righe o colonne per ottenere una combinazione definita in cui le pedine (3) sono montate scorrevoli a contatto una con l'altra entro scanalature ricavate sulla superficie di una sfera (1) lungo circonferenze di cerchio massimo perpendicolari tra di loro. Il perfezionamento consiste in una struttura costituita sostanzialmente da un elemento centrale (5), una pluralità di spicchi (2) e un elemento di bloccaggio o cursore (10).
Patent IT-1258460-B (IT)
Title: Proiettore per veicoli
IPC: B60Q1/04
Filed: 1992-08-21
Granted: 1996-02-26
Abstract: La domanda riguarda un proiettore per autoveicoli, che è ribaltabile da una apertura della carrozzeria attorno ad un asse trasversale per la sostituzione di lampadina e che presenta una leva a cerniera da fissare sul lato del veicolo. Per rendere possibile un ribaltamento del proiettore anche nelle sfavorevoli condizioni di ingombro, l'invenzione propone di fissare la leva a cerniera dal lato del veicolo in modo scorrevole in direzione longitudinale del veicolo in una guida di scorrimento all'incirca orizzontale dal lato del veicolo, di far sporgere dalla leva a cerniera una linguetta elastica con una piastra di arresto prevista sulla sua estremità libera della linguetta che entra, nella posizione di fuoriuscita massima ammissibile del proiettore, in un intaglio a finestra della guida di scorrimento e di conformare la piastra di arresto alla sua estremità poste-riore in un piano inclinato di invito, che rende possibile al rinserimento del proiettore un rientro della piastra di arresto nella guida di scorrimento.
Patent IT-1261224-B (IT)
Title: Use of asbestos-containing wastes in combination with steel industry waste products such as refractories and slag for the production of rock wool
Inventor: SOMMOVIGO PAOLO
IPC: C04B/
Filed: 1993-04-06
Granted: 1996-05-09
Abstract: The invention relates to the use of asbestos-containing wastes in association with wastes from the manufacture of steel, such as waste refractories, steel-making and/or blast-furnace slags for the manufacture of rock wool.
Patent IT-1262388-B (IT)
Title: Boiler using electrical power for providing hot water for heating and domestic use
IPC: F24H/
Filed: 1993-08-06
Granted: 1996-06-19
Abstract: The boiler substantially comprises two or more containers, of which at least one is intended for domestic water and one is intended for water for heating, each of which containers are provided with an electrically powered heat source such as a resistance, and which are in a mutual position such that there is heat exchange between them although the waters are kept completely separate at all times according to their use. The containers are placed one above the other and have at least one common surface separating them for heat exchange, and the upper container which is intended for water supply for the heating system is provided with a hermetically sealed expansion vessel which takes up the changes in the volume of the water. In a variant the two containers are contained one within the other and the inner container is composed of three superimposed cylindrical chambers intercommunicating with the heating electric resistance located in the intermediate chamber. The walls separating the two fundamental containers are strong transmitters of heat and have any shape and profile. <IMAGE>
Patent IT-1274949-B (IT)
Title: Equipment for measuring the electrical properties of superconducting specimens and process for the said measurement
Inventor: FONTANA FABRIZIO
IPC: G01R/
Filed: 1994-10-12
Granted: 1997-07-29
Abstract: Equipment for measuring the resistive transitions of HCTS materials, consisting essentially of a cryostatic container 1 into which the specimen holder 2 is lowered, a certain number of valves V1, V2, V3 for approximate and fine pressure control; tubes for the entry of gas at high pressure 3 and low pressure 4; a vessel for the gas at low pressure; a safety outlet 8 for the gas, fitted to the cryostatic container; and a vessel 9 for the gas at high pressure. The invention resolves problems relating to the measurement of the resistive transitions and of the voltage-current characteristics of specimens of material of the HCTS type, with transition temperatures varying from 85 to 110 K. The object of the invention is to make it possible to analyse specified materials in conventional superconductors at temperatures including the low critical temperature and in each circumstance in which analysis is required in the said temperature range. The equipment relates to the field of measurement and control and can be applied especially to the field of superconductor manufacturing. <IMAGE>
Patent IT-1252371-B (IT)
Title: Machine for mixing and homogenising viscous liquid products contained in pre-packaged drums, especially paint, varnish, and stains, more generally solutions containing solid solutions dispersed in solvents
Inventor: PERINI BERNARDO
IPC: C09K/
Filed: 1991-01-24
Granted: 1995-06-12
Abstract: This is a device which lies in the field of production of stains or paints or varnishes; it is used to mix and make homogeneous viscous fluids, such as enamels, varnishes and stains; the invention involves a kinematic mechanism which, from an imposed rotary motion, produces a second rotary motion with axis of rotation perpendicular to the preceding one and with fixed velocity relation between the two motions, or a relation which varies by a predetermined law, in order to optimise the mixing process. It is used at paint or stain factories or stores which produce paints or stains or enamels from mixtures of base stains in appropriate batches. <IMAGE>
Patent IT-1273138-B (IT)
Title: Hydraulic shift type transmission system
Inventor: GUSELLA RICCARDO
IPC: F16N/
Filed: 1994-04-13
Granted: 1997-07-04
Abstract: The hydraulic shift type transmission is essentially comprised of: a series of hydraulic groups G mounted on the primary shaft 1, these being firmly joined to toothed wheels W [illegible] with the secondary shaft 2. Said groups consist in a [illegible] integrated with the primary shaft 1, inside which are produced several radially arranged cylinders, able to lodge pistons subjected to lifting by means of springs and descending by means of the cam formed inside the shell which will lodge the monobloc. When said hydraulic groups are in movement, they will create a continuous displacement of hydraulic potential from the holes located at the bottom of each cylinder and all of them coming together in the central conduit of the primary shaft 1. By using the valve cursor to close the passage of the hydraulic potential of a group, and therefore a ratio that one intends to use, the axial movement of the pistons is blocked, and therefore the pistons blocked in "raised" position will grasp the shell, thus transmitting the desired ratio to the primary shaft 1. <IMAGE>
Patent IT-1262205-B (IT)
Inventor: DI GIUSTO BRUNO
IPC: B21C5/00
Filed: 1993-09-28
Granted: 1996-06-19
Abstract: Machine to sharpen bars to a point, especially bars to be drawn, which comprises at least one sharpening assembly and at least one assembly for displacement of the bar in relation to the sharpening assembly, the sharpening assembly (31) consisting of two counterpart rolls (11) each of which contains on the plane of positioning of the bar a groove (24) including at least two sections of reduction, means (14-15) being comprised for the circumferential positioning of the rolls (11) at the desired section of reduction, there also being included at least one rolling assembly (27a) upstream of the sharpening assembly (31) and at least one rolling assembly (27b) downstream of the sharpening assembly (31), such rolling assemblies (27) operating on the bar on a plane substantially at a right angle to the plane of reduction. <IMAGE>
Patent PT-103297-B (PT)
Title: Dispositivo para carga horizontal de contentores
Inventor: FRAZAO ELISEU
IPC: B66F9/14
Filed: 2005-06-28
Abstract: A PRESENTE INVENÇ&O DIZ RESPEITO NA SUA GENERALIDADE AO CARREGAMENTO DE OBJECTOS DE ELEVADO PESO, E CONCRETAMENTE A UM NOVO E MELHORADO MÉTODO E DISPOSITIVO DE CARREGAMENTO DE CONTENTORES, QUE PERMITE A COLOCAÇÃO DE CARGAS DE ELEVADO PESO E DIMENSÕES AO LONGO DE TODO O COMPRIMENTO DO CONTENTOR POR MEIO DE ARRASTAMENTO. DE MODO A CUMPRIR A TAREFA MENCIONADA, PROPÕE-SE UM DISPOSITIVO COMPOSTO POR UMA BASE OU ESTRUTURA FIXA (1) QUE APRESENTA NA ZONA POSTERIOR UMA SÉRIE DE ROLOS (4) E NA EXTREMIDADE DOIS PIVOTS (5); SOBRE ESTA BASE FIXA DESLIZA UMA ESTRUTURA MÓVEL INFERIOR (2) PELA A ACÇÃO DE UM CILINDRO HIDRÁULICO INFERIOR (7), SENDO A CARGA DESLOCADA PELA PRESSÃO DA BASE (6) EXISTENTE NA ESTRUTURA MÓVEL SUPERIOR (3) QUE SE DESLOCA MEDIANTE A ACÇÃO DO CILINDRO HIDRÁULICO SUPERIOR (8).
Patent PT-104927-B (PT)
Title: Placa higienizadora para absorção de fluidos fisiológicos
Inventor: GASPAR MARCELO RUDOLFO CALVETE
IPC: A01K1/015
Filed: 2009-12-30
Abstract: O PRESENTE INVENTO DIZ RESPEITO A UMA PLACA RÍGIDA DE MATERIAL COMPÓSITO QUE PERMITE UMA RÁPIDA E EFICAZ ABSORÇÃO DE FLUIDOS FISIOLÓGICOS E NEUTRALIZAÇÃO DE ODORES, COM O OBJECTIVO DE GARANTIR A HIGIENIZAÇÃO DE ESPAÇOS EM QUE SE ENCONTREM PESSOAS OU ANIMAIS, MAS QUE É ESPECIALMENTE VOCACIONADO PARA SER UTILIZADA POR ANIMAIS DOMÉSTICOS. ESTE INVENTO CONSISTE NUMA PLACA RÍGIDA DE MATERIAL COMPÓSITO CONSTITUÍDA POR DIFERENTES CAMADAS FUNCIONAIS, NOMEADAMENTE, CAMADAS HIGIENIZANTES (1), ABSORVENTES (2), ESTRUTURANTES (3) E ESTANQUES (4) . AS CAMADAS HIGIENIZANTES (1) SÃO COMPOSTAS FUNDAMENTALMENTE POR CARBONATOS, CELULOSE E AROMATIZANTES, ENQUANTO AS CAMADAS ABSORVENTES (2) TÊM POR BASE A CELULOSE, SILICATO DE CÁLCIO E CARBONATO DE CÁLCIO. AS CAMADAS ESTRUTURANTES (3) SÃO CONSTITUÍDAS POR MANTAS DE FIBRA DE VIDRO OU POR MALHAS OU MANTAS DE MATERIAIS METÁLICOS OU POLIMÉRICOS E AS CAMADAS ESTANQUES (4) SÃO COMPOSTAS ESSENCIALMENTE POR MATERIAIS POLIMÉRICOS.
Patent PT-108402-B (PT)
Title: Purificação de tricina obtida a partir de biomassa lenhocelulósica
Inventor: ANDRÉ MIGUEL DA COSTA LOPES
IPC: C08H8/00
Filed: 2015-04-28
Abstract: A PRESENTE INVENÇÃO DESCREVE UM PROCESSO DE PURIFICAÇÃO DE TRICINA, OBTIDA A PARTIR DE BIOMASSA LENHOCELULÓSICA POR EXTRACÇÃO COM LÍQUIDOS IÓNICOS, QUE COMPREENDE A UTILIZAÇÃO DE DUAS RESINAS POLIMÉRICAS DIFERENTES. O PROCESSO DE EXTRACÇÃO REQUER UM PROCESSAMENTO DA BIOMASSA LENHOCELULÓSICA COM LÍQUIDOS IÓNICOS E, POSSIVELMENTE, UM FRACIONAMENTO DA BIOMASSA NAS SUAS FRAÇÕES PRINCIPAIS, NOMEADAMENTE, CELULOSE, HEMICELULOSE E LENHINA. SEGUIDAMENTE, A FASE LÍQUIDA CONTENDO LÍQUIDO IÓNICO JUNTAMENTE COM UMA MISTURA DE COMPOSTOS FENÓLICOS EXTRAÍDOS DA BIOMASSA LENHOCELULÓSICA É SUBMETIDA A UM PROCESSO DE SEPARAÇÃO ATRAVÉS DE UMA RESINA POLIMÉRICA, QUE SELETIVAMENTE SEPARA UMA FRAÇÃO ENRIQUECIDA EM TRICINA. APÓS ESTE PASSO, A FRAÇÃO ENRIQUECIDA EM TRICINA É PURIFICADA ATRAVÉS DE UMA SEGUNDA RESINA POLIMÉRICA PARA SE OBTER TRICINA COM ELEVADA PUREZA. UMA VANTAGEM DESTE PROCESSO É A POSSÍVEL INTEGRAÇÃO DE UM FRACIONAMENTO PRÉVIO DA BIOMASSA LENHOCELULÓSICA COM A VALORIZAÇÃO DE COMPOSTOS FENÓLICOS DE VALOR ACRESCENTADO, DE QUE É EXEMPLO A TRICINA, QUE PODE SER DIRETAMENTE COMERCIALIZADA.
Patent RO-92723-B (RO)
Inventor: BEAT BOHNER
IPC: C07D277/68
Filed: 1984-12-04
Abstract: Inventia se refera la o compozitie erbicoda lichida avand, în calitate de substanta activa, cel putin o cinamida de acid 2-fenoxipropionic cu formula generala I: (vezi formula) în care R reprezinta hidrogen, alchil cu 1..4 atomi de carbon, alchenil cu 3..4 atomi de carbon, alchinil cu 3..4 atomi de carbon sau alcoxialchil cu 2..4 atomi de carbon si T reprezinta un radical cu formula: (vezi formula) în care A reprezinta oxigen sau sulf, X reprezinta fluor, carbon, brom sau trifluormetil si Z reprezinta azot sau metilen, asociata cu agenti activi de suprafata si materiale de suport lichide.
Patent TW-315302-B (TW)
IPC: A61K8/00
Filed: 1992-06-30
Granted: 1997-09-11
Abstract: Ampholyte terpolymer conditioning additives for hair care products are disclosed which improve wet and dry hair combability, especially detangling and reduced static flyaway, sheen, and fixative properties, especially curl retention. The ampholyte terpolymers may have a weight average molecular weight of from about 10 thousand to 10 million, and comprise (a) from at least 1 to as much as 95 weight percent of the nonionic monomer acrylamide (AM), (b) from at least 5 to as much as 80 weight percent of (DMDAAC), and (c) from at least 1 to as much as 75 weight percent of the anionic monomer acrylic acid (AA). In a preferred embodiment, the amount of the cationic and anionic components is such that the overall % net charge of the ampholyte terpolymer is between -5.0 and +5.0. The ampholyte terpolymers are added to hair care product formulations in amounts ranging from 0.1-10% by weight. They are particularly compatible with anionic surfactant shampoos, providing clear formulations without the loss of conditioning properties described above.
Patent TW-218379-B (TW)
Title: Hydroxymethylpolythiophene derivative
Inventor: CHANG JIIN-DER
IPC: C07D409/00
Filed: 1992-09-16
Granted: 1994-01-01
Abstract: A compound of formula (I) and its medical acceptable salts, in which n = 0, 1, 2; R = CHR1OR2, CHO, CH(O C1-Cr alkyl)2, COR3; R1, R3 = H, C1-C4 alkyl; R2 = H, C1-C4 alkyl, Pyrazolidinyl, C1-C6 acyl, C3-C6 dicarboxylicmonoester; however, in the formula, the compound representted byn = 0, R = CH2OCH3, R1 = H, R2 = CH3 is not included.
Patent TW-234195-B (TW)
IPC: H01G4/10
Filed: 1993-07-14
Granted: 1994-11-11
Abstract: Tantalum electrode material is produced which has extremely low tortuosity, exceptionally low ESL and ESR, potentially extended high frequency performance, very high volumetric efficiency, and reduced tantalum consumption per electrode. The electrode material is characterized by having a cross-section composed of plates of tantalum separated by spaced gaps resulting in a highly dense (volumetric efficiency) electrode. The plates are electrically interconnected which also adds to the structural stability of the article. This is made possible by being able to carefully control the geometry of the tantalum material during processing. A method for producing such material includes extruding a billet filled with a (preferentially geometrically uniform) mixture of rods of tantalum and an extrudable metal. When the billet has been sufficiently reduced in size and severed, the extrudable metal is removed by selectively dissolving with acid. In addition to the above advantages, the resulting article is particularly adapted for use in super-miniaturization applications.
Patent TW-275063-B (TW)
Title: Method of preparing pyridine methanol derivatives
Inventor: CHEN SY-FENG
IPC: C07D213/30
Filed: 1994-06-10
Granted: 1996-05-01
Abstract: A method of preparation of pyridine methanol derivatives is comprising of: adding Grignard dosage solution to an aromatic solvent to produce a mixed solution; reacting alkoxy carbonyl pyridine or its derivatives with the above premixed solution to obtain magnesium complex or magnesium salt of pyridine methanol derivatives; mixing the solution of aromatic solvent which consists of one of the following: benezen, toluene, xylene, or dichloro benezene with Grignard dosage at the ratio of 1:4~1:1:10; adding tetra-ethoxy carbonyl pyridine to the premixed solution at the temperature between -78~25 deg.C; reacting under nitrogen monoxide; adding tetra-ethoxy carbonyl pyridine to the premixed solution for 20~60 minutes; mixing the premixed solution for 2 hours then raising the temperature to 25 deg.C and further mixing for 16 hours or more.
Patent TW-353170-B (TW)
Title: Communications card with integral transmission media line adaptor
Inventor: MOSHAYEDI MARK
IPC: H01R31/00
Filed: 1995-01-16
Granted: 1999-02-21
Abstract: A communications card for electrically interfacing a computer with a transmission media line having a transmission media line connector, the communications card comprising a card body having first and second electrical terminals and an internal cavity which houses logic circuitry that communicates with the first and second terminals, and an adaptor which removably attaches to the card body in a first location in which the adaptor electrically connects to the first terminal, and which removably attaches to the card body in a second location in which the adaptor integrates with the card body to present a generally rectangular configuration.
Patent TW-331513-B (TW)
Title: The machine for making brush
Inventor: BART GERARD BOUCHERIE
IPC: A46D3/00
Filed: 1995-04-27
Granted: 1998-05-11
Abstract: A machine for making brush, it includes a mold for injection forming brush body, which has tufts of bristles embedded in molding material. This mold includes a mold portion, which has recess for fitting insert holes of each tuft inside. The lining pattern of each insert holes is corresponding to the tuft pattern of to-be-produced brush, and supplying a tuft feeding station for guiding tuft into insert holes to insert each tuft hair into mold cavity. Its features are: The tuft feeder includes several tuft picking-up stations, and each tuft picking-up station has a connecting bristle container and a set of tuft picking-up tube. The connecting bristle container includes different kinds of to-be-processed bristle, and has installed several tuft carriers moving in between tuft picking-up station for sending the tuft picked-up from tuft container to mold.
Patent TW-377447-B (TW)
Title: Improved field emission cold cathode having micro electrodes of different electron emission characteristics
Inventor: MAKISHIMA HIDEO
IPC: H01J1/30
Filed: 1995-11-29
Granted: 1999-12-21
Abstract: In a field emission cold cathode composed of a plurality of micro cold cathodes, the diameter of a plurality of openings in a gate electrode is large at the central region of an electron emission zone but small at the peripheral region of the electron emission zone. Or else, the thickness of the gate electrode is small at the central region of the electron emission zone but large at the peripheral region of the electron emission zone. Alternatively, the thickness of an insulator layer is small at the central region of the electron emission zone but large at the peripheral region of the electron emission zone. Or, an impedance layer is provided between a substrate and a plurality of electron emission electrodes, and impedance of this layer is small at the central region of the electron emission zone but large at the peripheral region of the electron emission zone.