baber/WOPTO huggingface dataset:
Patent CN-1118659-A (CN)
Title: 茶萃出物的酶化澄清方法
Inventor: AGBO FRANCIS ONAH
IPC: A23F3/16
Filed: 1995-05-11
Abstract: 本发明公开了一种在冷藏贮存时其混浊程度会大为减少的茶萃出物的生产方法。该方法包括培养氧化酶、丹宁酶和茶萃出物的混合物，然后从茶萃出物中分离出不溶性固形物。茶萃出物优选为一种浓缩汁，随后将该浓缩汁稀释得到即饮饮料。茶萃出物或由该萃出物制备的茶饮料在冷藏时可显著地降低其混浊程度。
Patent CN-1198970-A (CN)
Title: 锻造部件成型机模具装置及其配用方法
Inventor: ZHANG YUNDE
IPC: B21J13/02
Filed: 1997-05-09
Abstract: 本发明提供一种锻造部件成型机模具装置及该模具装置的配用方法,该模具装置有多种不同规格化主模及多套不同规格尺寸的周边配件,而且一些周边配件也可包含至少一个打头模垫块或模具垫块,该模具装置可装设在相同模具容设空间的同型机台上,也可装设在不同模具容设空间的不同型机台上。
Patent CN-1243576-A (CN)
Title: 微机械半导体装置及制造微机械半导体装置的方法
Inventor: MUELLER K
IPC: G01P15/08
Filed: 1998-01-05
Abstract: 本发明涉及具有在一个空腔(9)内构成一个膜片(7)的一种微机械半导体装置。膜片(7)是由在半导体装置上的一个基片(1)内的或在一个基片(1)上安排的外延层序列内的一个结晶层构成的。膜片(7)的边缘区域是支撑在一个支柱(6)上的,和由支撑在一个支座(5)上的一个盖层(4)覆盖着的。支柱(6)和支座(5)为一方面和膜片(7)为另一方面,是用对一种预先规定的湿法化学腐蚀剂有不同的腐蚀速率的材料制造的,并且最好是用不同的掺杂材料构成的。
Patent CN-1309774-A (CN)
Title: 角测量或限定物体角位置的方法及装置
Inventor: JARPINEN RISTO
IPC: G01S5/16
Filed: 1999-07-15
Abstract: 本发明涉及一种用于角测量或确定物体角位置的方法及装置,该方法包括使用具有已知位置并绕其轴旋转的一个信标(15),其发射光或反射聚集在其上的光,该光从预先或每次测量开始时以确定给定参考方位(R)的信标发射,在该方法中,通过被测量物体中的接收机(16)来拾取从信标(15)发射的光,该接收机设有用于确定的部件(12,13),通过从信标接收到的光,确定信标旋转速度以及物体相对于所述参考方位(R)的角位置(α)。通过使用每端具有接收机的常规基底该方法还能测量距离,从而可通过计算三角或通过测量接收机之间的圆周速度以及通过使用信标角速度的知识来确定被测量物体和信标之间的距离。
Patent CR-20220221-A (CR)
Title: Anti-cd79 chimeric antigen receptors, car-t cells and uses thereof
Inventor: GANESAN RAJKUMAR
IPC: C07K16/28
Filed: 2020-11-17
Abstract: The present disclosure provides for chimeric antigen receptors (CARs) that specifically target a Cluster of Differentiation 79b protein (CD79b), and immunoresponsive cells comprising such CARs, for the treatment of cancer.
Patent EC-SP003668-A (EC)
Title: Tratamiento para los estados alergicos e inflamatorios (caso alo1056k)
Inventor: AFFRIME MELTON B
IPC: C07D221/00
Filed: 2000-09-20
Abstract: Se describe el uso de la desloratadina para la preparación de un medicamento para tratar y/o prevenir los estados alérgicos e inflamatorios de la piel o vias aéreas superiores o inferiores en un humano, mientras que, al mismo tiempo, se evita el efecto de los alimento asociado con las antihistaminas no sedativas, por ejemplo, loratadina o fexofenadina.
Patent EC-SP972229-A (EC)
Title: Procedimiento para la produccion de 2h-1-benzopiranos
Inventor: BOSSARD PIERRE
IPC: C07D209/88
Filed: 1997-08-14
Abstract: Un procedimiento para la producción de 2H-1-benzopiranos con la fórmula general (gráfico), en la que R1 es hidrógeno, un grupo alquilo (C1-C4), R3 es hidrógeno, un grupo alquilo (C1-C6) y R3 es hidrógeno, un grupo alquilo (C1-C4), un grupo haloalquilo (C1-C4), un grupo alquenilo (C2-C4), un grupo alcoxi (C1-C4)-carbonilo, un grupo alcoxi (C1-C4)- metilo, un grupo alcanoilo (C1-C4), un grupo alcoxi (C1-C4), un grupo alquil (C1-C4), sulfonilo, halógeno, amino, alquilamino, dialquilamino, nitrilo, nitro o hidroxi, caracterizado porque en una primera etapa un aldehído alifático con la fórmula general (gráfico), en la que R1 y R2 tienen los significados antes mencionados, se convierte, con un alcohol alifático de la fórmula R4OH o HOR4OH donde R4 es un grupo alquilo (C1-C4) o un grupo alquildiilo (C2-C4), en presencia de un compuesto deshidratante de la fórmula HC(OR5)e en la que R5 es un grupo alquilo (C1-C4), y de un catalizador de óxido de aluminio/óxido de silicio, en un acetal alifático de la fórmula general (gráfico), en la que R1 y R2 tienen los significados antes mencionados y R4 como se ha indicado antes, es un grupo alquilo (C1-C4) con los dos R4 juntos son un grupo alquildiilo (C2-C4) cíclico, y este se condensa entonces en una segunda etapa, con un fenol de la fórmula general (gráfico), en la que R3 tiene el significado mencionado antes, en presencia de una base en un disolvente orgánico inerte, hasta el producto final de la fórmula general I.
Patent EC-SP993096-A (EC)
Title: Revestimiento corneo
Inventor: STEELE JOHN GERARD
IPC: A61F2/14
Filed: 1999-08-12
Abstract: Se da a conocer un revestimiento córneo o implante córneo que se va a colocar adentro o sobre la superficie de la córnea, que es un material polimérico biocompatible, ópticamente transparente, sintetico y biostable, comprendido este material una superficie que soporta la unión y el crecimiento de células de tejido, y en donde la superficie externa del implante sobre la cual se va a atraer y se va unir el tejido epitelial, o en el caso de un revestimiento córneo, la superficie anterior del revestimiento, tiene una topografía que comprende una pluralidad de identaciones superficales.
Patent EC-SP993272-A (EC)
Title: Equipo de control de flotabilidad de un oleoducto y componente del aditamento para amarres para el mismo
Inventor: KIRK WILLIAM D
IPC: F16L1/20
Filed: 1999-12-16
Abstract: Un equipo de control de flotabilidad de un oleoducto incluye un par de barras de anclaje, un par del miembros del aditamiento de amarre, un par de miembros de terminación y una banda sin fin flexiblke que tiene una configuración de circuito sin fin. Las barras de anclaje se hunden parcialmente en el suelo a lo largo de los lados laterales opuestos del oleoducto. Los miembros del aditamiento de amarre se disponen sobre y se montan en las porciones finales superiores de las barras de anclaje en la que cada miembro del aditamiento de amarre tiene un cuerpo de montaje tubular que define un pasadizo axial a través del cual se extiende la porción final superior de una barra de anclaje y un cuerpo sujetador dispuesto en una relación oblicua y se une al cuerpo de montaje tubular. Cada miembro de terminación se monta sobre la porción final superior de una de las barras de anclaje. La banda sin fin tiene porciones opuestas aseguradas a los miembros del aditamiento de amarre y porciones principales colocadas sobre la aprte suiperior y dispuesta en una relación substancialmente transversa al oleoducto y extendida entre y fijada a las porciones opuestas. El cuerpo sujetador de cada miembro del aditamiento de amarre define un reborde anular que descansa sobre y rodea una de las porciones opuestas de la correa sin fin de modo que mantenga la correa sin fin en su lugar sobre la parte superior del oleoducto de tal modo que una carga de flotabilidad del oleoducto se extienda sobre las barras de anclaje y por lo tanto reduzca la presión aplicada a las barras de anclaje.
Patent FI-19992001-A (FI)
Inventor: KOSONEN PAAVO
IPC: H03M1/14
Filed: 1999-09-20
Abstract: A calibration equipment for calibrating an analog-to-digital converter, which calibration equipment comprises means for supplying control codes to the analog-to-digital converter, whereupon a digital value is obtained as the output of the converter, means for calculating a residual of the voltage sector to be calibrated as a difference of the second and the first digital value, means for calculating a correction term related to the voltage sector by adding the correction term of the adjacent calibrated voltage sector to the residual of the voltage sector and means for using the correction term in correcting the digital value obtained from the analog-to-digital converter when the analog-to-digital converter is used to convert a signal included in the voltage sector from an analog into a digital form.
Patent FI-20002150-A (FI)
Inventor: PAANANEN HANNU
IPC: B01J39/04
Filed: 2000-09-29
Abstract: The invention relates to a method comprising a multistep process for recovering betaine, erythritol, inositol, sucrose, mannitol, glycerol and amino acids from corresponding starting materials. The invention comprises the use of a weakly acid cation exchange resin in chromatographic column in the multistep process. The starting materials are especially beet molasses, betaine molasses, syrups, thick juices, raw juices, corn steep cane based solutions and glycerol.
Patent FI-20021231-A (FI)
Inventor: VEIJANEN PAAVO
IPC: G02B6/44
Filed: 2002-06-24
Abstract: An arrangement in a fibre process, which arrangement is equipped with control and pulling means for directing fibre along a desired run and with means equipped with gripping surfaces ( 7, 8 ) for gripping the fibre or the like ( 1 ), between which gripping surfaces ( 7, 8 ), the fibre or the like ( 1 ) is arranged to run without touching the gripping surfaces before the gripping step, in which the gripping surfaces ( 7, 8 ) are arranged to press against each other. On both sides of the fibre-gripping surfaces ( 7, 8 ), control means ( 10, 11, 12, 13 ) are arranged to prevent a random contact between the fibre or the like ( 1 ) and the gripping surfaces ( 7, 8 ).
Patent FI-20060017-A (FI)
Inventor: GILHOUSEN KLEIN S
IPC: H04B7/005
Filed: 2006-01-11
Abstract: A method for achieving the soft or softer handoff process such that the performance of a system is improved is based on delaying the softer handoff process. <??>Reverse link demodulation in each sector may continue with or without the transmission of the forward link. The operation could be based on the signal strength of the reverse link signal or the forward link. It is also possible to combine two or more methods to create a hybrid symbol. <IMAGE>
Patent GB-1052235-A (GB)
IPC: C08G77/08
Abstract: 1,052,235. Linear organo-polysiloxanes. MIDLAND SILICONES Ltd. Oct. 21, 1963 [Aug. 2, 1962], No. 29722/62. Heading C3T. Cyclic diorganosiloxanes of formula wherein R and R<SP>1</SP> are each a monovalent saturated or unsaturatod hydrocarbon or halogenated hydrocarbon radical and n is an integer from 3 to 5 are polymerized to form substantially linear siloxane polymers by contacting said diorganosiloxanes at below 100‹ C. with a mixture of (1) an anhydrous acid having a dissociation constant in aqueous solution of at least 10<SP>-5</SP> and (2) a halide as defined. The halide is a Lewis acid type halide and is a compound of Al, Ti, Zr, Sn, As, Sb, Fe or Pt in their highest valency state, e.g. AlCl 3 , TiCl 4 , SnCl 4 , PtCl 4 , FeCl 3 . Halides of phosphorus and substituted halides of phosphorus, e.g. PCl 5 , PCl 3  or phenyl dichlorophosphine may be used. The anhydrous acid may be: HCl pyrophosphoric acid, CCl 3 CO 2 H, toluene sulphonic acid, benzene sulphonic acid, benzoic or acetic acid. In Examples (1) and (2) octamethyl cyclotetrasiloxane was polymerized in the presence of (1) HCl gas and anhydrous FeCl 3  and (2) CCl 3 CO 2 H and FeCl 3 . In Example (4) the hydrolysate of methyl γ chloropropyl dichlorosilane was polymerized in the presence of FeCl 3  and CCl 3 CO 2 H.
Patent GB-1095395-A (GB)
IPC: H04M3/54
Abstract: 1,095,395. Automatic exchange systems. ELECTRONIC ENGINEERING PROPRIETARY Ltd. Dec. 14, 1964 [Dec. 16, 1963], No. 50835/64. Heading H4K. In a substation having two exchange lines and provided with apparatus which enables a call received over one line to be transferred to another predetermined number, a call on the other line is initiated by a relay responsive to ringing current, and an impulsing device sends the required number, the call being completed through the substation when the called party replies by a ring-trip relay which operates as the result of a current reversal. If the required number is busy or unobtainable, a second number may be called, or even a third. Detectors may be provided which are responsive to dial tone, busy tone and so on. The impulsing device may comprise a pair of interconnected relays together with a counting switch. A line amplifier may be included in the connection if desired. Instead of impulse sending a call may be initiated at a manual exchange, the required number being given by a tape recorder. The arrangement may be used to give an alarm signal, for example, of a burglary or fire.
Patent GB-1095410-A (GB)
IPC: C08J9/20
Abstract: 1,095,410. Suspending agents in polymerization systems. MONSANTO CHEMICALS Ltd. Nov. 28, 1966 [Jan. 11, 1966], No. 1232/66. Headings C3C and C3P. Polymerization of olefinically unsaturated monomers is carried out in an aqueous suspension system that contains as suspending agent a surface-active agent and a copolymer of vinyl pyrrolidone with an ester of an acrylic acid. The exemplified monomer is styrene. The surface-active agents may be anionic, non-ionic or cationic, preferably anionic, e.g. the alkalimetal salts of organic sulphonic acids, and are preferably substantially insoluble in organic solvents. The composition comprising a surface-active agent and a copolymer of vinylpyrrolidine with an ester of an acrylic acid, wherein the surface-active agent is substantially insoluble in organic solvents is claimed per se. Volatile liquid blowing agents, e.g. pentane, may be present during polymerization and result in the production of foamable resin beads (see Example 5).
Patent GB-1095570-A (GB)
IPC: B01F7/18
Abstract: 1, 095, 570. Centrifugal pumps. H. G. V. ANDERSSON. April 30, 1965, No. 18321/65. Heading F1C. A submersible centrifugal pump for pumping matter, such as manure, sludge, mud and like matter containing roots and like fibres suspended in water comprises an impeller having upper and lower discs 6, 5, Fig. 1, connected by two vanes 8. The lower disc 5 is slit at two places, one edge of each slit being bent downwardly as shown so that two blades 7 are formed. The blades 7 have a shearing action relative to a stationary partition disc 3 mounted below the impeller and having an oval intake opening 4, whereby straw and like material is cut into small pieces. Two discharge pipes 10, 11 are connected to the top of the pump casing at diametrically opposite points, the pipe 10 being vertical while pipe 11 is bent towards the pipe 10 to join the latter. At the junction between the two pipes a short horizontal by-pass pipe 12 is provided. A shutter 13 can be opened to allow pumped water to be discharged through the by-pass pipe 12 back to the body of water in which the pump is submerged, whereby agitation is effected before pumping of the matter suspended in the water can commence.
Patent GB-1225683-A (GB)
IPC: H04N9/825
Filed: 1968-03-11
Abstract: 1,225,683. Colour television. NIPPON ELECTRIC CO. Ltd. 11 March, 1968 [11 March, 1967], No. 11766/68. Heading H4F. [Also in Division G5] The luminance component of a colour television signal is recorded in oblique tape tracks by rotating magnetic heads, while the two chrominance components are recorded longitudinally of the tape by a stationary magnetic head or heads. The system is applicable to Y, I, Q or Y, X, Z standards. The video signal 22 is divided into its various components and the Y-signal frequency modulated 25 and recorded by heads 5a, 5b driven by motor 44. The Y-signal is monitored through the receiver at terminal 53a via switch 35a, limiter 36 and demodulator 37 and the vertical sync. pulses separated at 38 and used to generate 60 c/s. pulses in generator 39. These pulses are multiplexed with the chrominance I- and Q-signals, frequency modulated 29, 30 and recorded by stationary heads 18a, 18b as well as being fed via switches 48a, 49a and demodulators 50, 51 to monitoring terminals 53b, 53c. The pulses are also fed via switch 40a to a comparator 41 controlling the motor speed in accordance with speed detector 45. The signals are reproduced with the various switches in position b, the Y-signals being fed through a switching circuit 34 synchronized with the rotation of the heads 5a, 5b, and the I- and Q-signals being fed through demodulators 50, 51, the former feeding a sync. separator 52 used to control the motor speed. The stationary head assembly includes two erase and three record/playback heads for the chrominance and audio signals and the various heads are screened from one another (Fig. 3, not shown). In a modification, the outputs from modulators 29, 30 are fed to a gate operated by horizontal sync. pulses separated from the video signal to generate a sequence of alternate I- and Q-signals, I 1 Q 2 I 3 Q 4  ... which are frequency modulated and recorded in a single track. The reproduced signal is fed to two inputs of a switching device, one input being delayed, to generate separate I- and Q-channels, each consisting of alternate fields repeated once, I 1 I 1 I 3 I 3  ... and Q 2 Q 2 Q 4 Q 4  ... which are subsequently demodulated. Slow motion colour and still black-and-white pictures are obtained by adjusting the tape speed and placing the switches in a neutral position.
Patent GB-1225746-A (GB)
IPC: B60N2/18
Filed: 1969-01-27
Abstract: 1,225,746. Adjustable seats. ISRING- HAUSEN GEB. 27 Jan., 1969 [1 Feb., 1968], No. 4394/69. Heading A4J. The height and inclination of a vehicle seat are adjusted by means of angle members 2 which are secured to the vehicle chassis via a plate 1 and are provided with notches 3 in which pins 5a on the base plate 4 of the seat may engage, the pins being held in position by an eccentric lever 7a which is secured to an eccentric shaft rotatably mounted on the plate 4. The lever 7a may be held in engagement with the angle member by means of a spring 9 which is secured at one end to an anchoring pin 10 on the lever 7a, the position of pin 10 being such that on rotation of the shaft 6, the spring 9 passes through its maximum stretched position and is prevented by a stop 11 from returning to the position in which curved surface 8 engages member 2.
Patent GB-1226658-A (GB)
IPC: C25D21/18
Filed: 1968-08-01
Abstract: 1,226,658. Plating -electrolyte regenerative system. AMERICAN BANK NOTE CO. Aug. 1, 1968 [Aug.3, 1967], No.36868/68. Heading C7B. In an electro-plating apparatus using an insoluble anode the electrolyte used is circulated to a regenerating apparatus comprising consumable electrodes of the metal to be deposited in the plating apparatus, connected to the poles of an A. C. power source, the electrolyte being regenerated by exposing opposed surface areas of the electrodes which are connected to opposite poles of the A. C. power source, cyclically and out of phase with each other, and synchronizing therewith the alternating current supplied to said electrodes such that the exposed area of the electrode or electrodes, forming the anode is a maximum and that of the electrode or electrodes forming the cathode is a minimum when the current flow between the electrodes is a maximum, and hence maximum dissolution of the anode and minimum plating out on the cathode takes place. In the form shown electrolyte from the plating bath 1 is cycled through a regenerating bath 9 which is provided with electrodes 10 and 11 connected to the A. C. current supply 32 via transformer 30. The electrodes 10 and 11, when the bath 1 is used for electro-plating with nickel, are formed of nickel balls supported within guides 12 and 13 terminating in cages 14, 15 respectively, and which extend within the bath 9. Means comprising two semi-circular discs 20a, 20b rotatable about axes 16b and 16c respectively, in opposing directions is positioned in front of the electrode 10, and a similar structure is positioned in front of the electrode 11, rotation of the discs being arranged such that amount of the electrode shielded by the discs is at a maximum or a minimum as required, such rotation being provided by means of motor 17, chain drive 16g and various gearing arrangements.
Patent GB-1229064-A (GB)
IPC: B60T11/26
Filed: 1969-03-28
Abstract: 1,229,064. Hydraulic brake reservoirs. SOC. ANON D.B.A. 28 March, 1969 [9 April, 1968], No. 16304/69. Heading F2F. A flexible sealing diaphragm 10 for a reservoir such as that for a master cylinder comprises an upper flange 12 adapted to be maintained in sealing engagement with the free upper edge of the reservoir by a cap, a flat bottom 18 and a sidewall formed with folds defining triangles connected between the outer edge of the bottom and the inner edge of the flange. As shown, the inner edge 20 of the flange and the edge of the bottom 18 are both pentagonal, and the sidewall has two sets of folds 22, 24. Fig. 3 represents the appearance of the diaphragm in a partially-filled reservoir, the bottom 18 being in contact with the liquid surface. As the liquid level falls, the bottom 18 will rotate in the direction of arrow A and simultaneously descend. For all changes of liquid level, up or down, the bottom 18 will perform a substantially helicoidal displacement relative to the flange 12. The polygons 20 and 18 are preferably identical and may have four or six sides instead of five. Preferably the diaphragm is made of a flexible elastomeric material such as latex gum.
Patent GB-1232908-A (GB)
IPC: A23B4/08
Filed: 1969-11-10
Abstract: 1,232,908. Preserving meat. SWIFT & CO. 10 Nov., 1969 [26 Dec., 1968], No. 54967/69. Heading A2D. Red meat is preserved by treating the surfaces thereof with nicotinic acid or a salt thereof in an amount insufficient to impart any artificial colour to the meat and freezing the meat to produce a product having prolonged colour stability even when exposed to light. The nicotinic acid or salt thereof may be utilised in solution and sprayed on to the meat. The nicotinic acid may be present on the meat in an amount of less than 250 p.p.m. The treated meat is frozen and may be vacuum packed in a flexible transparent film.
Patent GB-1238585-A (GB)
IPC: A61B8/06
Filed: 1969-08-22
Abstract: 1,238,585. Ultrasonic measurement of speed; ultrasonic probes. SIEMENS A.G. 22 Aug., 1969 [22 Aug., 1968], No. 42079/69. Headings H4D and H4J. In a system for measuring the speed of moving material by an ultrasonic Doppler-effect method, two mutually perpendicular ultrasonic beams are directed towards a point of interest in the material, whereby the measurement can be made independent of the direction of motion. As applied to the measurement of blood flow in a vessel 2 (Fig. 1), echoes at Doppler-shifted frequencies fd 1  and fd 2  respectively are returned to transducers 4, 5 both transmitting a frequency fo. Voltages #f 1  and #f 2  proportional to the difference frequencies are extracted (Fig. 2) (by biased diodes, not shown) at 6, 7, squared at 11, 12; the squares are added at 15 and; the square-root of the sum is derived at 16 and divided at 16<SP>1</SP> by a factor 2# 0 /c (c being the sound velocity) to give a voltage at indicator or recorder 17 proportional to blood flow velocity and idependent of the angles between the flow direction and the ultrasonic beams. Transducers 4, 5 may be used for transmitting only, each being paired with an adjacent receiving transducer. If transducers 4, 5 each function as transmitter/receiver, interference between them is prevented by operating them alternately or with different respective transmission frequencies (e.g. 5MHz and 7 MHz): in the latter case the Doppler voltage #f 2  is multiplied at 10<SP>1</SP> by a correction factor which is the ratio of the two frequencies used. Transducer details (Fig. 3). Piezoelectric transducers 4, 5 in probe 3 are acoustically coupled to the body of a patient via water-filled chamber 19 and flexible diaphragm 18. The transducer separation may be adjustable to vary the depth a (Fig. 2) at which the ultrasonic beams intersect. Probe 3 is held in place by suction cup 21, by a strap through slot 22, or by adhesive.
Patent GB-1257649-A (GB)
IPC: F15C1/02
Filed: 1968-12-20
Abstract: 1,257,649. Fluidic elements. NETHERLANDS APPLIED SCIENTIFIC RESEARCH FOR INDUSTRY, TRADE & COMMERCE. 20 Dec., 1968 [20 Dec., 1967], No. 60723/68. Heading G4P. [Also in Division G3] A wall-attachment fluidic switch, Fig. 2, for OR/NOR operation has a nozzle 15, vents 5 and 6, outlets 7, 8, and control inputs 2, 2<SP>1</SP>. The jet attaches to the wall of outlet 7 in the absence of a signal at either control input, and to wall 12 of part 14 in the presence of a control signal. Part 14 defines a recirculation path 13 downstream of the jet, avoiding the need for a vent adjacent nozzle 15. A turbulence amplifier, Fig. 6, has control inputs 2, 2<SP>1</SP>, vents 19, 20 and outlet 7, 8. Recirculation paths 24, 25 and short-circuit paths 21, 22 are provided, the paths 24, 25 incorporating damping spaces 26, 27. Constrictors may be fitted in the recirculation paths or vents.