Showing papers on "Oxalic acid published in 1968"

L-glyceric aciduria. A new genetic variant of primary hyperoxaluria.

Abstract: Four patients (three of them sibs) with recurrent calcium oxalate kidney stones excreted urinary oxalic acid and also an organic acid absent from normal urine and shown to be L-glyceric ac...

Oxalic acid metabolism in man: A review

Abstract: The presence of oxalic acid in mammalian tissues and body fluids has been recognised for over a century but detailed knowledge of the metabolism of this acid has been hindered until recently by a lack of reliable analytical techniques, particularly for the determination of oxalic acid in blood. Calcium oxalate crystals were first identified in urine by Do~N~ in 1838 and in the following years numerous a t tempts were made to correlate the excretion of oxalate crystals with clinical symptoms. The te rm \"oxaluria\" was introduced to describe the presence of excessive quantities of calcium oxalate crystals and, by implication, an increased excretion of oxalic acid. I t is now recognised, however, that the occurrence of these crystals depends on several factors such as the diet and the concentration of other solutes in urine. The te rm \"oxalaemia\" was also used frequently in the earlier literature to describe a high concentration of oxalic acid in the blood. \"Oxalaemia\" has been reported in a var iety of conditions such as diabetes, cirrhosis of the liver and cardiac failure but the analytical techniques which were used in these studies are now known to be unreliable (Jv~H~RS and MURPHY, 1945; WYNGAARD~.N and ELDER, 1966). The effects of oxalic acid poisoning in man and animals at t racted early interest and led to the identification of calcium oxalate crystals in kidney tissue by a number of German workers, for example KOBERT and KOSS~R (1879). In recent years, oxalic acid has a t t racted interest in relation to the formation of calcium oxalate stones in the kidney and to the occurrence of calcium oxalate deposits in soft tissues notably in patients with pr imary hyperoxaluria. The purpose of this review is to summarise current knowledge of the biochemistry and physiology of oxalic acid in man, particularly in relation to calcium metabolism.

Isolation of Plant Cuticles With Zinc Chloride-hydrochloric Acid Solution.

Abstract: rhe cuiticle of plants is a heterogenous memnbranie in which wax, pectin and cellulose in varying l)ro)ortions are contained in a cutin franmework. In the isolation of cuticular membranes from leaves or fruits the wax is nornially removed by extraction xvith ani organic solvent before detachment of the memnbranes from the underlying epidermal cells. Detachnmenit is achieve(d by the use of either ammoium oxalate/oxalic acid solutioln (1) or l)ectic enzymes (2) both of which attack pectin occtirrinig where the membrane merges with the outer epidermal cell wall. Cellulose may be subsequently remiioved froni the isolated membranes by treatnmelnt witlh cul)ralnnlonium ( 3 ) or zinc chloride-hydroebloric acid (4) solution;s. We have found durinig ail examination of a wide range of plants that the pectic enzyme and ammoiiium oxalate/oxalic acid methods completely failedl to detach either upper or lower membranes from certain leaves., With many leaves a partial or total (lisintegrationi of both membranes occurred (luritng (letachment. In other cases the uppel or lowel miembrane onlwas release(l. Somiie of these effects have beeln reported by Orgell (2) uising pectic enzymes. He suggested thlat cuiticular menmbranes wvere more readilv releasedi frolmi leaves in which

Aqueous polymerization of acrylic acid initiated by KMnO4 — H2C2O4 redox system

Abstract: Polymerization of acrylic acid in aqueous solution initiated by permanganate-oxalic acid redox pair has been studied at 32 ± 0.2°C in nitrogen atmosphere. The rate of polymerization has been found to be nearly independent of oxalic acid concentration within the range 1.87 to 9.33 · 10−3 mole/l. and decreases only at higher concentrations of the oxalic acid. The rate has also been found to vary with the first power of the monomer concentration (within the range 1.44 to 5.76 · 10−2 mole/l.) and the first power of the catalyst concentration (8.0 to 28.0 · 10−5 Mole/l.). It is, however, proportional to half power at relatively high catalyst concentration, at fixed concentrations of oxalic acid (1.03 · 10−2 mole/l.) and the monomer (5.76 · 10−2 mole/l.). At higher concentration of monomer the catalyst exponent has been found to be nearly unity for both the higher and lower concentrations of the catalyst. The initial rate of polymerization increases with increase in temperature. The overall energy of activation has been found to be 19.56 kcal/mole within the temperature range 30 – 45°C. Organic solvents and salts (KCI, Na2SO4, and Na2C2O4) depress the rate but MnSO4 4H2O has been found to increase the initial rate but depress the maximum conversion.

Reaction Rates of Second-Phase Constituents in Aluminium During Etching, Brightening and Oxalic Acid Anodizing Processes

Abstract: The behaviour has been examined of second-phase constituents in super-purity aluminium during etching in caustic soda, chemical brightening and anodizing in oxalic acid. Specimens containing large ...

Bis-oxalic acid ester amides for use as ultraviolet stabilizers

Abstract: The present invention provides a process for protecting organic materials that can be damaged by ultraviolet light from the effects of ultraviolet rays, characterized in that a bis-oxalic acid amide ester is incorporated with, or applied to the surface of the materials to be protected, or a filter layer containing the bis-oxalic acid amide esters is placed in front of said materials, the said bis-oxalic acid amide ester corresponding to the formula A1-O-CO-CO-NH-W1-NH-CO-CO-O-B1 in which A1 and B1 are identical or different and each represents an organic residue and should not displace the absorption maximum of these compounds to values above 370 Mu ; W1 represents an organic residue and should not displace the absorption maximum of these compounds to values above 370 Mu ; W1 represents an organic residue, and X1 represents an alkylene group containing one to four carbon atoms or a bridge member -O-, -S-, -N- or -SO2-. Furthermore the invention discloses a certain class of novel symmetric bis-oxalic acid amide esters as defined by formula (6) of the specification and a process for the manufacture of the symmetric bis-oxalic acid amide esters defined above.

Method for separating alcohols and hydrated alumina from hydrolysts products of aluminum alkoxides

Abstract: An improvement in a method for separating a hydrolysis product of an aluminum alkoxide into two layers of a higher alcohol layer and an aqueous layer containing readily precipitatable hydrated alumina in a suspended state. The hydrolysis reaction mixture is heated, either during or after the hydrolysis, at a temperature of 130 DEG -250 DEG C. in the presence of an ammonium, sodium or potassium salt of carbonic acid, hydrochloric acid, nitric acid, sulfuric acid, hydrobromic acid, phosphoric acid, formic acid, acetic acid or oxalic acid. The hydrated alumina is separated from the aqueous layer and the separated hydrated alumina is markedly low in content of impurities of organic matters.

New possibilities for routine use of oxalic acid solutions in in-pile dosimetry.

Abstract: New data are given on the use of oxalic acid, in light and heavy water solutions, for in-pile chemical dosimetry. The method of calculating the absorbed doses in low-Z materials is described. Results of chemical measurements in the core of the heavy-water-moderated reactor at Vinca (Yugoslavia) are compared with the results of calorimetric measurements conducted under identical conditions.

Structural steel members and method of making same

Abstract: 1,153,202. Coated steel. HUTTENWERK OBERHAUSTEN A.G. 12 July, 1966 [18 Feb., 1966], No. 31209/66. Heading B2K. [Also in Division C7] Steels which are to be used for external facings of buildings are formed with a coating of rust by applying an aqueous solution of an iron salt, e.g. nitrate, and a heavy metal, e.g. Cu or Ni, sulphate, and then applying a protective film which is permeable to water vapour. The film may comprise natural or synthetic resins, waxes, silicones or cellulose or rubber derivatives and may include silica gels or the stearates or carbonates of Zn or Al. The aqueous solution may comprise (% by weight):-iron nitrate 5 to 15, copper sulphate 0.1 to 2, nickel sulphate 0.1 to 2, glycerine 0.1 to 1, oxalic acid 0.1 to 2, wetting agent 0.01 to 0.1 alcohol 10 to 50, water-balance. The protective film may comprise (% by weight):- cyclo rubber 5 to 40, carbon tetrachloride 40 to 90, silica gel 2 to 20, ferrous hydroxide 0.1 to 2.0, higher alcohol (12 carbon atoms) 0.1 to 2.0.

Novel phenyl and naphthalene substituted oxalic acid diamides useful as protection agents against ultraviolet irradiation

Abstract: The present invention provides a process for protecting organic materials which may be damaged by exposure to ultraviolet rays, from damage by ultraviolet irradiation, characterized in that an oxalic acid diamide derivative is incorporated with or applied to the surface of the materials to be protected or in front of said materials a filter layer is placed that contains such oxalic acid diamide derivative of the formula: Ar1-NH-CO-CO-B1 in which Ar1 represents a benzene or naphthalene residue, which may be substituted by phenyl, benzazolyl, cyclohexyl, benzoyloxy or aliphatic groups with not more than 20 carbon atoms, and wherein B1 represents a residue of the partial formula- NH-D1 or WHERE D1 stands for a possibly substituted alkyl group, alkenyl, hydroxyl, cycloalkyl, carboxylic or sulfonic acid group or a functional derivative thereof; Q represents a member selected from the group consisting of hydrogen, hydroxyalkyl, alkoxyalkyl and Q+W represents a piperidino and a morpholino residue and W stands for a member selected from the group consisting of hydroxyalkyl, alkoxyalkyl, acyl, a carboxylic group, a sulfonic acid group, a functional derivative thereof, a residue of the formula- NHWx (where Wx is hydrogen, alkyl, acyl or phenyl), and an aminoalkyl group whose amino group may be alkylated, cycloalkylated or arylated.

Preparation of finely-divided metals

Abstract: Finely-divided iridium or ruthenium is produced by thermally decomposing, under non-oxidizing conditions and at a temperature not exceeding 400 DEG C., a halogen-free compound containing iridium or ruthenium in a complex in which the complexing groups comprise at least one of ammonia or oxalate groups, the balance of the compound consisting of groups that decompose and volatilize at the decomposition temperature to leave no residue. Suitable compounds are:- trisoxalato iridous-III acid ammonium trisoxalato iridite-III and ruthenate-III ammonium bis-oxalato bis-hydroxo ruthenate-III ammonium oxalato bis-carbonate ruthenate-III ammonium oxalato tetra-nitrito ruthenate-III hexammino ruthenium-III oxalate oxalato tetrammino ruthenium-III oxalate. tetrammino bis-aquo ruthenium-III oxalate. Decomposition may be effected under hydrogen with or without nitrogen, or carbon monoxide. Supported catalysts may be produced by impregnating carbon or g -alumina with a solution of the complex, drying to deposit the complex and then heating to decompose the complex. Mixed catalysts consisting of iridium-ruthenium or containing other platinum-group metals may be produced by thermally decomposing mixtures of complexes. Suitable ammonium compounds of palladium, platinum and rhodium containing oxalate groups are disclosed. The finely-divided iridium and ruthenium are also useful in the production of coatings and sintered compacts.ALSO:Organic Ru and Ir compounds which may be thermally decomposed to yield finely-divided metal are prepared as follows:- (1) Ammonium trisoxalato ruthenate-III: (NH4)3[Ru(C2O4)3]. Ruthenium dioxide is dissolved in aqueous ammonium acid oxalate by heating, excess of the latter is precipitated by n-propanol after the solution has cooled, and acetone then added. (2) Ammonium bis-oxalato bis-hydroxo ruthenate-III: (NH4)3[Ru(C2O4)2(OH2)]. As (1) except that n-propanol is added to hot solution. (3) Ammonium oxalato bis-carbonato ruthenate-III: (NH4)3[Ru(C2O4)(CO3)2]. A solution of compound (1) is heated with lead carbonate and ethanol subsequently added. (4) Ammonium oxalato tetra-nitrito ruthenate-III: (NH4)3[Ru(C2O4)(NO2)4]. A solution of compound (1) is heated with silver nitrite. (5) Hexammino ruthenium-III oxalate: [Ru(NH3)6]2(C2O4)3. Ammonia gas is passed through a solution of compound (1). (6) Oxalato tetrammino ruthenium-III oxalate: [Ru(NH3)4(C2O4)]2(C2O4). Ammonia gas is passed through an aqueous suspension of compound (5). (7) Tetrammino bis-aquo ruthenium-III oxalate: Ethanol is added to an aqueous solution of compound (6). (8) Trisoxolato iridous-III acid: H3[Ir(C2O4)3]. Iridium dioxide is heated with aqueous oxalic acid. (9) Ammonium trisoxolato iridite-III: (NH4)3[Ir(C2O4)3] A solution of compound (8) is neutralized with potassium bicarbonate, shaken with a sulphonated polystyrene cation exchange resin in the calcium form to precipitate excess oxalate, passed through the same resin to remove potassium ions, and then passed through the resin in ammonium form.ALSO:Supported catalysts are produced by impregnating carbon or g -alumina with a solution of a halogen-free compound containing Ir or Ru in a complex in which the complexing groups comprise at least one of ammonia or oxalate groups, drying to deposit the complex, and then heating to decompose it and deposit the Ir or Ru. Suitable compounds are:- trisoxalato iridous-III acid ammonium trisoxalato iridite-III and ruthenate-III ammonium bis-oxalato bis-hydroxo ruthenate-III ammonium oxalato bis-carbonato ruthenate-III ammonium oxalato tetra-nitrito ruthenate-III hexammino ruthenium-III oxalate oxalato tetrammino ruthenium-III oxalate tetrammino bis-aquo ruthenium-III oxalate Mixed catalysts consisting of Ir-Ru or containing other Pt-group metals may be produced by thermally decomposing mixtures of complexes. Suitable ammonium compounds of Pd, Pt and Rh containing oxalate groups are also disclosed.

Process for etching beryllium

Abstract: A process for chemical milling of beryllium and high beryllium alloys is described wherein the beryllium is subjected to an aqueous solution of an acid selected from the group consisting of sulfuric acid, oxalic acid, and ammonium acid fluoride plus sufficient hexavalent chromium ion to prevent channeling. In a preferred embodiment sulfuric acid is present in the range of 515 percent chromium ion is present in the range of 7-10 percent CrO3; sodium nitrate is present up to about 1.3 percent; and hydrofluoric acid is present up to about 2 percent.

Osmium tetroxide-catalysed oxidation of olefins

Abstract: A wide range of olefins are oxidised by osmium tetroxide in aqueous alkaline solution and the OsVIII is reduced to OsVI or OsIV. If the pH is kept in the range 8.5–12.5, it is possible to reoxidise the osmium compound to its initial state with oxygen at atmospheric pressure. Under these conditions osmium tetroxide acts as an oxidation catalyst. Simple alcohols, glycols, glycerol, acetone, and glucose are also oxidised under these conditions; the products are usually oxalic acid and carbon dioxide. Styrene gives benzoic acid and carbon dioxide.

Improvements relating to the sub-titling of processed photographic materials

Abstract: 1,260,662. Novolak resin. AGFA-GEVAERT. 13 March, 1969 [27 March, 1968], No. 14779/68. Heading C3R. [Also in Division G2] A novolak containing equimolar parts of phenol and p - t - butylphenol is prepared by mixing the phenols with formaldehyde and oxalic acid and refluxing and adding hydrochloric acid half-way through the reflux.

Carbon dioxide reduction with alkali-metal amalgams

Abstract: : The reduction of carbon dioxide by alkali-metal amalgams was studied as a potential means for reclamation of carbon dioxide waste gas in space systems. The carbon dioxide reduction reactions were investigated at moderate temperatures and pressures - typically 25 to 200 C and 1 to 1.1 atmospheres. The investigations demonstrated that carbon dioxide can be reduced effectively by an appropriate alkali-metal amalgam system. Moreover, the alkali-amalgam expended in the carbon dioxide reduction process can be reclaimed by electrolysis from an aqueous or nonaqueous salt solution containing the fixed carbon dioxide products. The carbon dioxide fixation products can be drained- off or, in some cases, recycled for further reduction. In the carbon dioxide reduction reactions by alkali-amalgam systems, a wide variety of products ranging from simple organic acids, such as formic and oxalic acid, to totally reduced carbon dioxide in the form of carbon black have been identified. The types of products formed are dependent upon such factors as the type of alkali- metal amalgam used, temperature, pressure, and electrolytic reducing conditions. In electrolytic recovery of the alkali-metal amalgam from aqueous media, oxygen also is produced as a useful by-product of the carbon dioxide reduction system.

Process of introducing ashing ingredients into oxidized cellulose material intended as smoking product and product obtained thereby

Abstract: A method of making a smoking product formed of oxidized cellulosic material is disclosed in which incorporation of ash forming components is effected in the form of mineralizing agents preferably developed in situ internally of the oxidized cellulosic fibers by treatment first with a calcium compound in aqueous medium and then with oxalic acid to form insoluble calcium oxalate in situ or by treatment of the cellulosic materials with the freshly mixed components which remain soluble in admixture for a length of time sufficient for internal absorption into the oxidized cellulosic system.

Mechanism of decomposition of jute and cellulose by a Corticium species.

Abstract: Growth of a Corticium species on jute fabric exposed to 100% relative humidity led to staining and deterioration of the fiber, showing evidence of considerable oxalic acid production and cellulase activity. Pure oxalic acid in excess of quantities produced by the organism did not degrade jute fabric to any comparable extent, and decomposition of cotton cloth was even less pronounced. Strength losses of jute and cotton yarn as a result of treatment with the cell-free culture filtrate were greater by far than those caused by the autoclaved filtrate, again suggesting cellulase action rather than oxalic acid as the main cause for deterioration.When the fungus was grown on jute and cotton fabrics suspended in a nutrient solution, losses in fabric strength were lower.Filter paper suffered a very small loss in weight when used as substrate for growth. The cellulase appeared to be random-splitting, adaptive, and extracellular in character, showing optimum activity at pH 4.0 and temperature 58 °C.

Thermodynamic Stability of Alkaline Earth Oxides and Aluminates in Flame Spectroscopy

Abstract: The suppressive interference of aluminum in the atomic absorption determination of calcium or magnesium has been commonly reported. Use of the high-temperature nitrous oxide-acetylene flame has also been shown to eliminate this interference. Prior to availability of this flame, use of controlling or releasing agents such as Sr salts, La, La+ EDTA, Ca, and oxine have been employed to compensate for this effect. Further tests in this laboratory using a Perkin–Elmer model 303 spectrophotometer and a fuel-rich air acetylene flame have shown 1% (w/v) of ammonium citrate or tartrate, oxalic acid, sodium nitrite, disodium EDTA, or sugar have little or no controlling action on aluminum at the pH of the dissolved salts. However, 0.5% (w/v) of hydroxylamine hydrochloride or 0.1% (w/v) of ethanolamine can compensate for 100-ppm A1 in determining 2-ppm Mg. Such releasing agents apparently exert a preferential reaction with either the aluminum or magnesium in the flame, allowing the magnesium compound to dissociate and manifest the atomic absorption phenomenon.

Preparation of hydrocarbon-soluble molybdenum and vanadium compounds

Abstract: Molybdenum and vanadium salts of C5- 50 carboxylic acids, which salts are soluble in liquid hydrocarbons, are prepared by heating an oxalate group containing compound of molybdenum at valence + 6 or of vanadium at a valence + 5, with a C5- 50 carboxylic acid at a temperature of at least 140 DEG C. for at least 2 hours. The preferred oxalate compounds are those obtained by heating 0.5-1.2 mols. of an inorganic compound of Mo+6 or V+5 with 1 mol. oxalic acid in the presence of 0.5-50 parts by weight water ser part oxalic acid, using sufficient water to dissolve the Mo or V compound, at 100-150 DEG C. under a pressure sufficient to maintain a liquid phase, for 1-2.5 hours, and then removing the water. This reaction may be effected in the presence of the C5- 50 carboxylic acid. Molybdenum trioxide and vanadium pentoxide are the preferred inorganic compounds. It is preferred to use alkyl, alkenyl or aralkyl mono-carboxylic acids. Examples relate to the preparation of hexanoates, octanoates and naphthenates of Mo and V.

Manufacture of oxalic acid

Abstract: 1,198,955. Oxalic acid preparation. ALLIED CHEMICAL CORP. 3 Jan., 1969 [24 Jan., 1968], No. 594/69. Heading C2C. [Also in Division C1] Oxalic acid is prepared by (1) reacting a carbohydrate with nitric acid (a) in a liquid reaction medium containing sulphuric acid and a catalyst, (b) at a temperature of 63‹ to 85‹ C., (c) under a pressure of at least 3A5 kg./cm. 2 gauge, (d) in the substantial absence of free oxygen, and (e) while maintaining the carbohydrate in the reaction mass in stoichiometric excess of the nitric acid; (2) absorbing oxides of nitrogen released from the reaction mass in an aqueous medium to form nitric acid, the absorption taking place in the presence of free oxygen and under a pressure of at least 3A5 kg./ cm. 2 ; (3) cooling the reaction mass to crystallize oxalic acid therefrom; (4) separating the crystallized oxalic acid; and (5) recycling the mother liquor of the reaction mass to step (1).

Cleaning of metal surfaces

Abstract: 1,126,476. Cleaning metals. E. I. DU PONT DE NEMOURS & CO. March 10, 1966 [March 10, 1965], No. 10640/66. Heading C7E. Metal surfaces, e.g. iron, steel, copper or brass are cleaned in an aqueous solution comprising 1 to 30% by weight of an organic or inorganic acid, a thiourea or a thioamide, and an anionic surface active agent which is an alkali metal or amine salt of an alkyl - or alkaryl sulphonic acid or a sulphonated ester of a mono - or di basic carboxylic acid. The surface may be subsequently rinsed in e.g. sodium hydroxide. The acid may be oxalic, sulphuric, sulphamic or hydrochloric. A typical example is:- oxalic acid 1A5%, sulphuric acid 5A0%, diorthotolylthiourea 0.2 g. 1.1., and sodium alkylarylsulphonate 0.14 g. 1.1.

Improvements in epoxide reactions

Abstract: 1277204 Curing epoxy resins DEFENCE SECRETARY OF STATE FOR 17 Nov 1969 [15 Aug 1968] 38998/68 Heading C3B [Also in Division C2] Epoxy resins are cured by polycarboxylic acids and/or carboxylated polymers using as catalyst a chromium (III) complex of salicyclic acid or a substituted salicyclic acid (see Division C2) Typical substituted salicyclic acids are chloro- or bromo-substituted salicyclic acids, cyclohexyl-, C 1-6 alkyl-, cyclohexyl- or phenyl- or methylphenyl-substituted salicyclic acids Typical chelates are bis-(3,5-diisopropylsalicylato)-monohydroxy chromium (III) and tris- (3,5-diisopropylsalicylato) chromium (III) The catalyst may be present at 0A001-5% of the total weight of epoxide and carboxylic acid Typical curing agents are carboxylated butadiene copolymers, oxalic acid, adipic acid, succinic acid, tartaric acid, citric acid, 3,3- ethylmethylglutaric acid and 3-tert-butyladipic acid Uses-Rocket propellant binders; adhesives