baber/WOPTO huggingface dataset:
Patent IT-1248401-B (IT)
Title: Punching and automatic winding machine for the production of frontal stators and rotors from magnetizable sheet- metal strip
Inventor: TEMPORITI LANFRANCO
IPC: B23P/
Filed: 1991-05-14
Granted: 1995-01-11
Abstract: Punching and automatic winding machine for the production of stators and rotors of the frontally recessed type from a strip of ferromagnetic sheet metal unwound from an idle reel, comprising a base supporting an eccentric-cam punching device intended to receive on one side said sheet metal to be cut and associated, on the opposite side, with a carriage displaceable along straight guides, said carriage having, mounted on it, a spindle for winding said sheet metal, arranged with its axis horizontal and subject to rotation with predetermined stoppages by means of an electric motor coaxial with the said spindle and able to impart to the said spindle predetermined angles of rotation synchronised with the sequence of the actions for cutting the cavities intended to form the recesses, said carriage being then subject to speed increases for movement away from the punching device by means of a mechanical mechanism actuated by an intermittently rotating electric motor synchronised with the movements of said punching device and with the angular displacements of said spindle, there also being provided a microprocessor or similar type electronic control unit suitable programmed and associated sensors suitable for ensuring the sequence of operating movements of said punching device and said motors rotating intermittently and in a predetermined manner. Upstream of said punching device there is a pair of parallel rollers of varying diameter designed to stretch the sheet metal at its yield strength and able to form, when winding has been completed, sets of cylindrical shaped spirals. <IMAGE>
Patent IT-1255589-B (IT)
Title: System for lodging the safety thermostat for hairdryers and electrical resistor designed for the purpose
Inventor: LOSINI FRANCO
IPC: A45D/
Filed: 1992-09-11
Granted: 1995-11-09
Abstract: A system is described for lodging the safety thermostat for hairdryers and an electrical resistor designed for this purpose. The system is characterised in that the safety thermostat is positioned beneath the electrical resistor, which is of the type with an electric resistive wire winding, in a zone where the individual turns of the electrical wire have a portion devoid of the corrugated appearance of the rest of their circumferential dimension. In particular, the appearance of the electrical wire in said zone will be of rectilinear type. Such a system of lodging makes it possible to reduce the overall dimensions of the heating element assembly. <IMAGE>
Patent IT-1272025-B (IT)
Title: Apparecchiatura per il serraggio e/o disserraggio di utensili in un mandrino.
Inventor: PEDROTTI RICCARDO
IPC: B23B31/12
Filed: 1993-03-15
Granted: 1997-06-10
Abstract: Un'apparecchiatura da applicare a qualsivoglia macchina che permette l'azionamento da parte della macchina stessa per ottenere il serraggio/disserraggio dell'utensile sul mandrino realizzando il necessario moto relativo tra albero del mandrino stesso e ghiera rotante di serraggio.
Patent IT-1269702-B (IT)
Title: Metodo ed apparecchiatura per aspirare e per asportare automaticamente la lanuggine e il pulviscolo in una stazione di roccatura
Inventor: BADIALI ROBERTO
IPC: B65H67/08
Filed: 1994-01-11
Granted: 1997-04-15
Abstract: La presente invenzione concerne un metodo per aspirare e per asportare automaticamente la lanuggine e il pulviscolo in una stazione di roccatura durante l'intero tempo operativo di raccolta del filo avvolto sulla bobina, di trattenere ed accumulare la lanuggine e il pulviscolo stessi nel noto condotto di aspirazione della fessura di pescaggio dell'estremità del filo avvolto sulla bobina e di allontanare detto accumulo ogni qualvolta si arresta l'avvolgimento.La presente invenzione concerne, altresì, l'apparecchiatura per l'attuazione del metodo in oggetto.
Patent IT-1272944-B (IT)
Title: Process for preparing a solution with a controlled concentration of chlorine dioxide
Inventor: PASTORE MAURO
IPC: C01B/
Filed: 1995-02-03
Granted: 1997-07-01
Abstract: This invention relates to a process for preparing a solution with a controlled dosage of chlorine dioxide for disinfectant and hygienic purposes which provides for the preparation of a first concentrated solution of chlorine dioxide in a first containment means, distribution of the vapours produced in water present in a second containment means having a closed opening and subsequent mixing of the two solutions.
Patent IT-1259056-B (IT)
Title: System of ferrules for fixing tubes for handlebars
Inventor: NASTRUCCI GIANFRANCO
IPC: B62K/
Filed: 1992-02-28
Granted: 1996-03-11
Abstract: The invention concerns a new ferrule for fixing the handlebar-adjusting tube. The ferrule placed underneath that retains the balls of the steering bearing is fitted with an externally threaded upper conical section and has vertical slots; a second ferrule is screwed onto the ferrule with slots and clamps the handlebar tube. <IMAGE>
Patent IT-1254377-B (IT)
Title: Procedimento per prelevare un carico da una pila.
IPC: B65G59/02
Filed: 1992-06-02
Granted: 1995-09-14
Abstract: Procedimento per prelevare un carico da una pila che comprende gli stadi di calcolare un'altezza di cui una paletta che porta una pila di strati di un carico su essa dovrà venire sollevata per rendere possibile all'estremità superiore della pila di raggiungere un livello prestabilito di altezza, per segnalazione, da dati di input sull'altezza di ciascuno degli strati e dal numero degli strati; sollevare la paletta fino a che l'estremità superiore viene rivelata a quel livello; calcolare l'altezza reale di ciascuno degli strati dall'altezza reale di cui la paletta è stata sollevata, e dal numero degli strati; sollevare la paletta per incrementi di un'altezza corrispondente ad una differenza tra l'altezza reale calcolata ed una prescelta costante, e prelevare il carico da quello più in alto degli strati mediante una tavola a moto alternativo ad una altezza fissata; il sollevamento per incrementi della paletta ed il prelievo venendo quindi ripetuti.
Patent IT-1256796-B (IT)
Title: Dispositivo di fissaggio di un rivestimento di sedile, ed organo di  aggancio alla cieca su un'asta conveniente per questo dispositivo
Inventor: COZZANI HENRI
IPC: B68G7/052
Filed: 1992-01-31
Granted: 1995-12-15
Abstract: Il dispositivo (1) comprende una barretta (2), sovrastampata su una striscia di tela (3), che fa parte di un insieme in materia plastica comprendente inoltre almeno un organo di aggancio (4) adatto ad agganciarsi alla cieca su un'asta.L'organo di aggancio (4) comprende un canale longitudinale (22) adatto ad alloggiare l'asta, un cuneo (23) ed una lamella elastica (27) scalata longitudinalmente in rapporto al cuneo (23).
Patent MX-171476-B (MX)
Inventor: EVRARD PAUL
IPC: A61K6/884
Filed: 1982-11-18
Abstract: A component system for surgical cement, based on at least one acrylic monomer and at least one acrylic polymer comprising a powder and a liquid. The powder comprises: (a) from 50 to 70 weight percent of at least one acrylic polymer having a particle size of between 20 and 150 microns; and (b) a polymerization initiator. The liquid comprises: (a) from 30 to 50 weight percent of a mixture comprising at least 65 weight percent of at least one acrylic monomer and up to 35 weight percent of at least one acrylic polymer; (b) at least one polymerization activator; and (c) from 0.05 to 1 weight percent, relative to the total amount of acrylic monomer, of at least one chain stopper chosen from the group consisting of diunsaturated monocyclic terpenes and monounsaturated bicyclic terpenes. Application to the manufacture of surgical cements.
Patent PT-100736-B (PT)
Inventor: HIGA TATSUO
IPC: C07H15/10
Filed: 1992-07-28
Abstract: A novel sphingoglycolipid represented by general formula (A), wherein R represents -CH(R2)-(CH2)X-H or -(CH2)7CH=CH(CH2)7-CH3; R1 represents -CH(R2)-(CH2)Y-R3 or -CH=CH-(CH2)Y-CH3; R2 represents H or OH; R3 represents methyl, isopropyl or sec-butyl; X represents an integer of 0 to 26; and Y represents an integer of 5 to 17. An antineoplastic agent and an immunopotentiator containing at least one abovementioned compound as an active ingredient. A process for preparing a sphingoglycolipid by taking a specified sphingoglycolipid out of a sponge Agelas mauritianus. <CHEM>
Patent PT-102060-B (PT)
IPC: C02F3/02
Filed: 1997-10-08
Abstract: The system claimed is based on a process of growing biomass in film created on a submerged expanded backing with bed expanded by downward flow. The flow rate necessary for said expansion is obtained at the expense of the nominal flow rate of effluent, to which is added the elevated rate of recirculation. This elevated rate of recirculation is induced by the actual mechanism of injection of air necessary for the biological process, which translates into high energy efficiency, inasmuch as both the recirculation and the expansion of the backing bed for the biofilm are obtained by the actual ventilation air. Said mechanism of injection of air will create a liquid column of lesser density, which is the determining factor in the hydraulic head difference capable of creating said flow rate. The process takes placed in a biological reactor, figure 1, comprised of one or more chambers 1, 2, 3 and 4, for growth of biological film, having a specific filling 1A, 2A, 3A and 4A, and one or more chambers for ventilation 5, 6, 7 and 8, and elevation of the circulating and recirculated effluent. In cases where the reactor has more than one pair of said chambers, these are arranged to form a horizontal series of pairs, pair 1, pair 2, pair 3 and pair 4, with recirculation enclosed circuit. The flow rate of circulating and recirculated effluent percolates, in descending flow, through the floating, contained, filling, inducing an expansion which creates the random motion of the component parts, promoting contact between the biofilm and the effluent being treated and at the same time facilitating the continual removal of biological sludge which will be transported by the effluent 9 and subsequently removed. Not requiring any submerged moving part or equipment - an indisputable advantage of this system - it has elevated energy efficiency, as well as an elevated efficiency for a mobile bed growth system, enabling an elevated recirculation flow. <IMAGE>
Patent PT-103434-B (PT)
Title: Método e sistema para a inferência de haplotipos por parcimónia pura usando satisfação proposicional
Inventor: SILVA JOAO PAULO MARQUES DA
IPC: G06F17/30
Filed: 2006-02-13
Abstract: UMA DAS PRINCIPAIS LINHAS DE INVESTIGAÇÃO EM GENÉTICA CONSISTE EM DETERMINAR A RELAÇÃO ENTRE MUTAÇÕES E DOENÇAS GENÉTICAS, PARA O QUAL É NECESSÁRIO PROCEDER À ANÁLISE DO HAPLOTIPO. UM HAPLOTIPO É UMA SEQUÊNCIA DE ADN EM QUE ESTÃO IDENTIFICADAS AS MUTAÇÕES GENÉTICAS. EM ORGANISMOS DIPLÓIDES OS HAPLOTIPOS ORGANIZAM-SE AOS PARES, EM QUE UM HAPLOTIPO É HERDADO DO PAI E OUTRO DA MAE. NO ENTANTO, DEVIDO A LIMITAÇÕES TÉCNICAS, É HABITUALMENTE OBTIDO O GENOTIPO, O QUAL COMBINA A INFORMAÇÃO CONTIDA NUM PAR DE HAPLOTIPOS. LOGO, NÃO É POSSÍVEL DISTINGUIR QUE MUTAÇÕES FORAM HERDADAS DE CADA PROGENITOR. O PRESENTE INVENTO REFERE-SE A UM MÉTODO E UM SISTEMA PARA A INFERÊNCIA DE HAPLOTIPOS POR PARCIMÓNIA PURA USANDO SATISFAÇÃO PROPOSICIONAL. ESTE MÉTODO E ESTE SISTEMA, QUE SE INSEREM NA ÁREA DA BIOINFORMÁTICA, PERMITEM INFERIR HAPLOTIPOS A PARTIR DE GENOTIPOS DE MODO A QUE O NÚMERO DE HAPLOTIPOS UTILIZADO SEJA MÍNIMO.
Patent PT-104637-B (PT)
Title: Processo de extracção líquido-líquido de ácido sulfúrico de um efluente e regeneração da fase orgânica para produção de sulfato de amónio, e respectivo equilíbrio
Inventor: CARVALHO JORGE MANUEL RODRIGUE
IPC: C01B17/775
Filed: 2009-06-19
Abstract: A PRESENTE INVENÇÃO DIZ RESPEITO A UM PROCESSO, E RESPECTIVO EQUIPAMENTO, PARA EXTRAIR ÁCIDO SULFÚRICO A UM EFLUENTE, COM PRODUÇÃO DE SULFATO DE AMÓNIO. ESTA TECNOLOGIA CONSISTE EM APLICAR EXTRACÇÃO LÍQUIDO- LÍQUIDO (ELL) A UMA CORRENTE COM ÁCIDO SULFÚRICO NUMA COLUNA DE ELL DE PULSO DE PRATOS PERFURADOS, E EXTRAI-LO SELECTIVAMENTE COM RECURSO A UM SOLVENTE ESPECÍFICO PARA O EFEITO. DE SEGUIDA, ESTE SOLVENTE É REGENERADO NUMA COLUNA DE ELL DE PULSO DE PRATOS PERFURADOS, OU NUM REACTOR MISTURADOR DECANTADOR, ATRAVÉS DA INJECÇÃO DE UMA SOLUÇÃO DE AMONÍACO PROVENIENTE DE UMA COLUNA DE ABSORÇÃO DE GASES. DESTA ETAPA RESULTA UMA CORRENTE SATURADA EM SULFATO DE AMÓNIO, QUE SEGUE PARA UM CRISTALIZADOR EVAPORATIVO PARA PRODUÇÃO DE SULFATO DE AMÓNIO CRISTALINO, QUE É UM PRODUTO COM ELEVADO VALOR COMERCIAL PARA O MERCADO DOS FERTILIZANTES AGRÍCOLAS. ESTE PROCESSO É APLICÁVEL, ENTRE OUTROS, NOS SECTORES INDUSTRIAIS MINEIRO, DO TRATAMENTO DE SUPERFÍCIES E DA PASTA DE PAPEL PERMITINDO RESOLVER PROBLEMAS COMO O DAS ÁGUAS ÁCIDAS DE MINAS, CONTROLAR O PH DAS LAGOAS DE REJEITADOS OU AUMENTAR O PH DAS PURGAS DOS BANHOS DE ELECTRÓLISE (TANK HOUSE ELECTROLYTES) E REMOVER O ÁCIDO SULFÚRICO DAS CORRENTES DE SAÍDA DO PROCESSO DE MATHIESSON NA INDÚSTRIA DA PASTA DE PAPEL. ESTA TECNOLOGIA REPRESENTA PARA ESTAS INDÚSTRIAS BENEFÍCIOS AO NÍVEL TECNOLÓGICO, ECONÓMICO E AMBIENTAL.
Patent PT-107601-B (PT)
Title: Oxo-complexo de vanádio(v) com ligandos 8-hidroxiquinolina e derivado de salicilaldeído-2-hidroxibenzoil-hidrazona e sua aplicação como catalisador para a oxidação peroxidativa, assistida por micro-ondas e sem adição de solvente, de álcoois secundários a cetonas
Inventor: MARIA DE FÁTIMA COSTA GUEDES DA SILVA
IPC: C07F9/00
Filed: 2014-04-14
Abstract: A INVENÇÃO REFERE-SE AO OXO-COMPLEXO DE VANÁDIO(V) COM LIGANDOS 8-HIDROXIQUINOLINA (HQH) E DERIVADO DE SALICILALDEÍDO-2-HIDROXIBENZOIL-HIDRAZONA (H2L) [VO(HQ)L] (1), (2-HIDROXI-N-[(2-OXIFENIL)METILENO]BENZENOCARBOHIDRAZONATO)(QUINOLIN-8-OLATO-N,O)-OXIDO-VANÁDIO(V), E AO SEU USO COMO CATALISADOR EFICIENTE E SELETIVO DA OXIDAÇÃO PEROXIDATIVA DE ÁLCOOIS SECUNDÁRIOS ÀS CETONAS CORRESPONDENTES, ASSISTIDA POR MICRO-ONDAS E SEM ADIÇÃO DE SOLVENTES. ESTE CATALISADOR É MUITO EFICAZ PERMITINDO RENDIMENTOS ATÉ 100% (QUANTITATIVOS) APÓS 30 MINUTOS DE REAÇÃO, E FREQUÊNCIAS DE CICLOS CATALÍTICOS, I.E., FREQUÊNCIAS DE ¿TURNOVER¿ (TOF), EXPRESSAS EM MOLES DE PRODUTO POR MOLE DE CATALISADOR E POR HORA, DE 3,6 X103 H-1.
Patent TW-222602-B (TW)
IPC: B32B7/00
Filed: 1990-05-05
Granted: 1994-04-21
Abstract: A polymeric composite structure having a configuration of a bathtub and a process of manufacturing the structure is disclosed. The polymeric composite structure includes an acrylic shell (12) and a plastic molded backing layer (14) which is bonded to a non-finish side (21) of the acrylic shell. A fiber reinforced resin layer, preferably fiberglass, is adhered to the non-finish side of the acrylic shell. A weight bearing reinforcing structure (16), such as chip-board, is adhered to the non-finish side of the shell (21) and to the fiber reinforced layer embedded within the molded polymeric backing layer. The molded polymeric backing layer (14) is made from a cross-linked thermosetting polymer, preferably a polyester blend, which does not contain isocyonate. The backing is bonded to the non-finish side of the shell and surrounds the fiber reinforcing and weight bearing reinforcing structures (16). The fiber reinforcing layer is bonded to the shell by a silane based coupler. The backing layer also includes a curing promoter, a peroxyde cross-linking promoter and a filler such as calcium carbonate, sand or other fillers. The composite structure is manufactured by a process which includes preforming an acrylic shell, reinforcing a non-finish side of the acrylic shell with a resinous mixture of reinforcing fibers by spray-up and roll-out techniques and arranging the reinforced shell in a mold with a non-finish side covering a reinforcing structure placed below the floor of the shell. An uncured mixture of the thermosetting polymeric backing and promoter is injected into the mold coating the non-finished side of the shell and covering reinforcing fibers and chip-board structure. The thermosetting backing material is cured sufficiently to permit demolding of the composite structure without damage. The shell is preferably primed with a silane based coupler prior to the reinforcing step. In an alternative manufacturing process, the spray-up reinforcing step is replaced by the placement of a fiberous mat within the mold, surrounding the non-finish side of the shell. The fiberous material may include a fiberglass woven or a mat material or it may include a preformed fiberous structure.
Patent TW-211574-B (TW)
IPC: A23L5/40
Filed: 1991-10-17
Granted: 1993-08-21
Abstract: Yeast refuse having a solids content not exceeding 20% by weight is digested with a food grade alkaline salt such as sodium bicarbonate, whole cells are separated from the extracted refuse so as to produce a material rich in disrupted cell walls which is then treated with an alkaline extraction agent and bleached either before or after the separation step, followed by lowering the pH of said bleached material using a food grade acid such as dilute hydrochloric acid. The product comprises a yeast beta-glucan which is substantially free of yeast cells, and which predominantly comprises a multiplicity of yeast ghosts or shells comprising substantially uncollapsed yeast cell walls. The yeast ghosts or shells contain a substantially lower quantity of yeast cell contents relative to the whole cells of the yeast refuse.
Patent TW-300200-B (TW)
IPC: C09D11/02
Filed: 1992-12-15
Granted: 1997-03-11
Abstract: A printing ink comprises a clear, transparent, polymeric carrier material and uniform, colloidal size charged color particles evenly dispersed therein. The carrier and the particles are adhesively bonded to one another so as to form a matrix which can collectively respond to an externally imposed electrostatic field to promote co-movement of a "bite" of ink to an imaging medium without change of the bulk particle/carrier ratio. During the printing process, the ink is melted and exposed to electrostatically charged latent image areas on a heated image cylinder, resulting in the transfer of the ink thereto in proportion to the electrostatic field strength. The ink exhibits a relatively sharp liquid-to-solid transition, thereby enabling rapid ink solidification and complete transfer from the imaging medium to the relatively cool printing substrate. Also disclosed is a printing method and apparatus that facilitate continuous, variable and on-demand color printing in conjunction with the ink. Use of essentially monodispersed, color-coated, colloidal size, spherical particles in the ink results in excellent color purity and chromaticity range.
Patent TW-267153-B (TW)
IPC: C07D417/12
Filed: 1993-09-24
Granted: 1996-01-01
Abstract: Disclosed herein are compounds of the formula:    A-N(R<1>)C(O)CH2CHR<2>C(O)-B   wherein A is an oxygen-bearing radical selected from the group consisting of: (a) HO-CH(R<3>)CH2 wherein R<3> is, for example, hydrogen, lower alkyl, lower cycloalkyl, phenyl or an unsubstituted five- or six-membered heterocyclic ring containing one or two heteroatoms selected from the group of N, O or S; (b) HO-CH2CH(R<4>) wherein R<4> is, for example, lower alkyl or phenyl(lower)alkyl; and (c) HO-CR<5>(R<6>)CH2 wherein each of R<5> and R<6> is lower alkyl; or R<5> and R<6> together with the carbon atom to which they are attached form a 1,1-(lower cycloalkanediyl), 1,1-(4-hydroxycyclohexanediyl) or 1,1-(4-oxocyclohexanediyl); (d) (lower alkoxy)CR<5A)<R<6A>)CH2 wherein each of R<5A> and R<6A> is lower alkyl; or R<5A> and R<6A> together with the carbon atom to which they are attached form a 1,1-(lower cycloalkanediyl); and (e) (lower alkyl)C(O)CH2; R<1> is, for example, benzyl, alkyl, a substituted alkyl such as cyclohexylmethyl, or R<7>R<8>NC(O)CH2 wherein R<7> and R<8> are alkyl such as methyl or ethyl; R<2> is, for example, alkyl, cycloalkylmethyl, 1H-imidazol-4-ylmethyl, 4-thiazolylmethyl or (2-amino-4-thiazolyl)methyl; and B is a renin substrate transition state mimic, for example, [1(S)-(cyclohexylmethyl)-2(R),3(S)-dihydroxy-5-methylhexyl]amino. The compounds inhibit renin activity and are indicated for the treatment of hypertension and congestive heart failure.
Patent TW-338125-B (TW)
Title: Novel matriz resin and its preparation and use in high-temperature stable photoimageable compositions
Inventor: RALPH R DAMMEL
IPC: G03F7/033
Filed: 1994-02-08
Granted: 1998-08-11
Abstract: A novel matriz resin comprising a homo-or co-polymer of a hydroxy-substituted styrene to which side groups have been grafted by a covalent chemical bond, wherein the side group is a novalak monomer or oligomer of the general formula: (formula) wherein R4, R6, R2, R5 and R7 hydrogen or alkyl, R8 hydrogen, C1-C4 alkyl, or methyllene, R9-R15 H and n = 0 to 2.
Patent TW-228611-B (TW)
Title: Isolation method for semiconductor integrated circuit
Inventor: SHYU JENN-CHYOU
IPC: H01L21/76
Filed: 1994-04-11
Granted: 1994-08-21
Abstract: An isolation method for semiconductor integrated circuit to fabricate electronic elements from semiconductor material with device regions, which comprises: - forming shield objects on the device regions of the semiconductor material; - taking the shield object as mask to set an isolation trough on the emiconductor material between device regions; - taking the shield object as doping mask for proceeding field doping to the solation trough to form channel stop region; - taking the shield object as the mask of liquid phase selective oxide eposition (LPD) to selectively form oxidation on the isolation trough by PD method.
Patent TW-304984-B (TW)
IPC: C22B7/02
Filed: 1994-04-30
Granted: 1997-05-11
Abstract: The working-up of zinc- and lead-bearing metallurgical plant residues is carried out by thermal treatment in a circulating fluidised bed, the heat requirement being met by combustion of solid carbon in the fluidised-bed reactor of the circulating fluidised bed. The solid carbon content in the lower part of the fluidised bed is adjusted to 5 to 30%. Oxygen-containing gases are introduced into the upper part of the fluidised-bed reactor, and the formation of CO2 is taken only so far that metallic zinc is not reoxidised. The discharged suspension is largely freed of solids in a return cyclone, and the solids are recycled. The gas is cooled to a temperature at which the metallic zinc is oxidised to ZnO, and the zinc and lead compounds in the form of dust are precipitated from the gas. <IMAGE>
Patent TW-336235-B (TW)
Title: 3'-aziridino-anthracycline derivatives, process for preparating them and pharmaceutical composition containing them
Inventor: ALBERTO BARGIOTTI
IPC: A61K31/7028
Filed: 1994-11-30
Granted: 1998-07-11
Abstract: A 3^-aziridino-anthracycline glycoside derivative of formula 1 or 2: where R1 is hydrogen or methoxy group; R2 is hydrogen, a hydroxy group or represents an acyloxy residue of formula 3; where R5 is a pyridyl group; R3 and R4 both represent hydrogen or one of R3 and R4 is hydrogen and the other is halogen atom or a group of formula -OSO2R8 in which R8 may be an alkyl group containing from 1 to 4 carbom atoms.