bluuebunny/crossref_metadata_2025_split huggingface dataset:
Colorimetric determination of tocopherol (Vitamin E): III. Estimation of tocopherol in blood‐serum
Authors: Emmerie A. , Engel Chr. 
Published: September 2010

AbstractIn this communication a method for the estimation of tocopherol in blood‐serum is described.The stability of tocopherol towards alkali and acid, and the saponification of acetyl‐tocopherol have been investigated.
The application of the cage theory of liquids to the problem of ion mobilities
Authors: Hermans J. J. 
Published: September 2010

AbstractWhen applying the cage theory of liquids to ions in solution it appears that the cage is much smaller for ions than for the solvent molecules themselves. This suggests that the walls of the cage are to be identified with the so‐called hydration layer. Further, the dimensions of the cage are such that classical and quantum mechanics apply equally well (or equally badly for that matter). An expression for the frequency of oscillation in the cage is proposed. On the basis of this expression it is possible to relate the ion mobility to its temperature coefficient. The agreement with experimental data is very satisfactory.The exceptionally high mobility of the hydrogen ions is easily explained by its dimensions compared with the dimensions of the smallest cage possible. Finally, it is shown that the effect of tunnelling through the walls of the cage is inappreciable.
Aliphatic polyamines IX
Authors: van Alphen J. 
Published: September 2010

AbstractLike 1:5‐dibromopentane, one mol of 1:4‐dibromobutane reacts with one mol of 1:2‐diaminoethane even when a large excess of the latter is present. The resulting product, 1‐(2′‐aminoethyl)‐pyrrolidine, has been investigated and it appears that most of its derivatives melt lower than the corresponding derivatives of 1‐(2′‐aminoethyl)‐piperidine.
New constituents of derris root III
Authors: Meijer Th. M. 
Published: September 2010

AbstractAdditional evidence for the structure of derride is given.The formation of 4‐hydroxycumarone‐5‐carboxylic acid by treatment of derride with alcoholic potash could be definitely proved.Derridenone was oxidised with hydrogen peroxide in alkaline medium and furan‐2,3‐dicarboxylic acid was isolated from the degradation products.Rissic acid and 2‐hydroxy‐4,5‐dimethoxybenzoic acid were found amongst the oxidation products obtained by oxidising dehydroderride with potassium permanganate in acetone.
Sur Quelques Corrections Essentielles dans les Analyses de gaz. (Suite)
Authors: Leendertse J. J. , Schefferxs F. E. C. 
Published: September 2010

AbstractLes écarts des hydrocarbures gazeux aux lois des gaz parfaits nécessitent l'application de deux corrections dans les analyses à volume constant. Ces deux corrections, celle de Dalton et celle d'Avogadro, sont calculées pour différents hydrocarbures et pour leurs mélanges. Elles sont comparées aux corrections analogues qui sont nécessaires dans les analyses à pression constante et qui ont été décrites antérieurement.
The influence of liver‐extract on the oxygen consumption of mammalian erythrocytes. III. On the mechanism of the reaction. A. Ascorbic acid systems
Authors: Overbeek G. A. 
Published: September 2010

Abstract1. Rats' liver‐extract contains substances titratable with iodine (probably ascorbic acid and glutathione), which disappear after shaking for two hours at 37°. Erythrocytes contain a reducing system, capable of preventing this oxidation.2. The mechanism of the respiratory reaction nevertheless cannot be identical with that of the ascorbic acid system of Von Szent‐Györgyi.3. A reversible or irreversible process of blood destruction cannot be the cause of the Michaelis‐Salomon effect, for liver‐extracts cause only a slight oxidation of haemochromogen, and spleen extract does not augment the oxygen consumption of a combination of liver‐extract and erythrocytes.
Vapour‐liquid equilibria in ternary systems: I. The course of the distillation lines
Authors: Reinders W. , de Minjer C. H. 
Published: September 2010

AbstractFor the practical use of liquid‐vapour equilibria in ternary systems the curves of simple distillation and of rectification are of great importance. A discussion is given about the course of these lines.In many systems the curves of simple distillation may be arranged in different bundles, separated by curved boundary lines. In some systems a boundary line for simple distillation may induce a similar boundary line for rectification, which, however, in other systems may be lacking.On rectifying, the change in composition of the boiling liquid will be determined by the distillate with minimum boiling point, and will therefore be indicated in the diagram by a straight line. When, however, the composition of the liquid reaches a point of a boundary line for rectification. It has to follow this line on further rectification. The composition of the distillate is then determined by the tangent to the boundary line; so it has to change gradually during prolonged rectification.
ρ‐Iodo‐benzhydrazide as a reagent for the identification of aldehydes and ketones
Authors: Sah Peter P. T. , Hsü Chang‐Lin 
Published: September 2010

AbstractThirty‐two crystalline p‐iodobenzoyl hydrazones, obtained by the action of p‐iodobenzhydrazide with various aldehydes and ketones, are described in this paper. The yields of the products from the reaction were so high that one could easily operate with 300 mg of the reagent to collect enough crystalline product for a study of its physical properties and for analysis.
ρ‐Iodo benzazide as a reagent for the identification of amines
Authors: Sah Peter P. T. , Wang Yü‐Kuang 
Published: September 2010

AbstractThirty‐six crystalline p‐iodophenyl‐ureas were prepared by the action of p‐iodobenzazide with various types of amines in boiling toluene solution. These new derivatives are suitable for the purpose of identification.
Vapour‐liquid equilibria in ternary systems: II. The system acetone‐chloroform‐benzene
Authors: Reinders W. , de Minjer C. H. 
Published: September 2010

AbstractIn this system the components are completely miscible in the liquid state. The boiling points and the equilibria liquid‐vapour at a pressure of 760 mm were determined. From the three binary systems only the system acetone‐chloroform has an azeotropic point, a maximum. The ternary liquid‐surface (boiling‐point‐surface) and the vapour‐surface have a ridge, going from the maximum on the acetone‐chloroform side, at 64.5° C and 78% chloroform, to the benzene point at 80.25° C.
Vapour‐liquid equilibria in ternary systems: III. The course of the distillation lines in the system acetone‐chloroform‐benzene
Authors: Reinders W. , de Minjer C. H. 
Published: September 2010

AbstractThe course of the lines for simple distillation was derived from the isotherms and the composition of various conjugate liquid and vapour phases. There is a boundary line for simple distillation, going from the maximum on the side acetone‐chloroform to the benzene point. It is obviously curved and touches the side benzene‐chloroform at the benzene point. The lines for rectifying distillation were experimentally determined starting with various mixtures. Their course agrees very well with the theoretical considerations. There is also a boundary line for rectifying distillation, which cannot be overstepped and practically coincides with the boundary line for simple distillation.
Sur L'hydrolyse de la Fibrine par L'hydroxyde de Sodium
Authors: van de Velde A. J. J. 
Published: September 2010

AbstractL'hydrolyse alcaline des protides de poisson permet la floculation, par prudente addition d'acides, de protides solubles dans un excès de ces acides; le même phenomène se produit pour d'autres protides, telle que la fibrine du sang. Les protides qui floculent dans ces conditions, sont plus complexes que les albumoses et sont provisoirement désignés sous la dénomination de protides B. Le facteur Kjeldahl de ces protides B est plus élevé que le facteur 6.25 généralement employé.
Reaktionen und Salzbildungen des Alloxans und Alloxantins. XII. Mitt. Systematischer Ausbau der Atomgruppen in der analytischen Chemie
Authors: Dubský J. V. , Keuning K. J. , Šindelář V. 
Published: September 2010

AbstractDas Studium der Reaktionen und der Salzbildung des Alloxans und Alloxantins beweist klar, dass die blaue Färbung der Ferrosalze mit Alloxan (resp. Ferrisalze mit Alloxantin) unrichtig gedeutet wurde (Liebig, Wöhler, Mulder, Denigès). Nur die Ferrosalze reagieren mit Alloxantin in ammoniakalischer Lösung, unter Bildung eines basischen Ferrosalzes des Alloxantins. Die früheren unrichtigen Angaben kann man leicht durch Reduktion des Alloxans bzw. Oxydation des Alloxantins erklären. Diese Reaktion ist spezifisch und die Erfassungsgrenze 1.7 γ Eisen.
Die Bildungswärme von Titandioxyd (Rutil)
Authors: Roth W. A. , Wolf Ursel 
Published: September 2010

AbstractReinstes Titan wird mit Cellophan als Initialzünder in der kalorimetrischen Bombe oxydiert. Da die Oxydation nicht ganz vollständig war und die Bildungswärmen der niederen Oxyde unbekannt sind, ist das Resultat mit einer gewissen Unsicherheit behaftet. Wahrscheinlich ist die Bildungswärme von TiO2 (Rutil) 219 kcal bei konst. Druck und 20° (Unsicherheit etwa 0.7%).
Some remarks on the determination of the “effective life” of the respirator “container” in a stream of air into which diphenylchlorarsine is liberated as a smoke
Authors: Jansen J. D. , de Graaf‐Peteri M. G. , de Graaf H. 
Published: September 2010

AbstractCertain difficulties made their appearance in the investigation of the “effective life” of the “container” of a respirator in an air stream into which diphenylchlorarsine is liberated as a smoke. In the present contribution is indicated how we have attempted to solve them with the aid of a formula with which the amount of arsine required for the test and also the effect of possible changes in the test can be calculated.
Elektrometrische Titration mit Glaselektroden
Authors: Aten A. H. W. , Boerlage Louise , Garssen J. E. 
Published: September 2010

AbstractEs wurde eine Jenaer Glaselektrode auf ihre Brauchbarkeit für elektrometrische Titrationen geprüft. Es zeigte sich, dass dieselbe sowohl für Titrationen in schwach alkalischen, als auch in schwach sauren Gebiete und auch für oxydierende Säuren sehr gute Resultate liefert. Die Handhabung der Elektrode und die Messmethode sind äusserst einfach.
The potential curve of the alkali halide molecules
Authors: Verwey E. J. W. , de Boer J. H. 
Published: September 2010

AbstractThe validity of the ionic picture of the bond in the vapour molecules of the alkali halides in the neighbourhood of the minimum of the potential curve is tested in this paper with the aid of experimental data from three different sources: (1) the distances between the nuclei at absolute zero temperature are calculated from those determined at 1200°C by electronic diffraction and from the atomic distances in the corresponding crystal lattices; (2) the first vibrational frequencies are calculated from the potential curve and compared with the values derived from the spectra; (3) the binding energies or molecular energies at absolute zero are calculated and compared with values derived from thermal data.A very good agreement is already obtained by the simple equation (Fig. 1), especially with reference to (1) (Fig. 3; Table II) and (2) (Table IV), with n = 11. The Born‐Mayer exponential repulsion equation is not applicable in this case. A still better approximation can be obtained by allowance for the mutual polarization; in that case also the calculated molecular energies are exactly of the right magnitude within the experimental errors (Table III). The best value of n for all alkali halides is apparently n = 12.
Das Gesamtbasenbindungsvermögen (T‐Wert) des mineralischen Bodenkomplexes und seiner Fraktionen von verschiedenen Bodentypen
Authors: Hissink D. J. 
Published: September 2010

AbstractDas Gesamtbasenbindungsvermögen (T‐Wert) des mineralischen Bodenkomplexes und seiner Fraktionen wurde für verschiedene Bodentypen bestimmt. Die T‐Werte für 100 g von Fraktion I (mineralische Teichen kleiner als 0.002 mm) wiesen dabei grosse Unterschiede auf (c‐Zahlen). Drei Hauptgruppen wurden unterschieden mit Durchschnittszahlen c = 164, 101 und 72. Die untersuchten Niederländischen Böden haben ziemlich gleiche c‐Zahlen zwischen 116 und 90; sie gehören alle zu der zweiten Gruppe (c im Mittel = 105). Betreffs der Ursache dieser Unterschiede werden einige Bemerkungen gemacht.
The azochromophor (IX)
Authors: Blumberger J. S. Petrus 
Published: September 2010

AbstractA spectroscopic method has been used for studying the effect of substitution in the benzene nucleus of o‐hydroxy‐azo‐dyestuffs of the type: benzene azo‐2‐hydroxynaphthalene 3: 6‐disulphonic acid, on the tendency of the hydroxyl group in these dyestuffs to dissociate in aqueous solution.There appears to be a connection between the optical and the chemical consequences of a particular substitution, in the sense, that a bathochromic effect goes parallel with an increased fastness to alkali, i.e. a decreased tendency to dissociation of the hydroxyl group, in agreement with what has already been postulatedIdem, Ibid. 30, 544 (1933).
.Ortho‐substitution (with regard to the azo group) leads to a considerably increased fastness to alkali. Since this is unaccompanied by any parallel optical effect, it would appear to originate away from the azo group. The effect of a second ortho‐substituent is completely different; the effect on the fastness to alkali is small and changeable, and the absorption band of the dyestuff is displaced towards a higher frequency.
Synthetic lubricating oil fractions from ethylene and gases containing ethylene by polymerisation
Authors: Hessels W. J. , van Krevelen D. W. , Waterman H. I. 
Published: September 2010

AbstractVarious methods of polymerising ethylene are described in the literature. Ethylene as such or in a liquid medium is polymerised with an aluminum chloride catalyst; the yield of lubricating oil fractions obtained by these known methods is relatively low, further they have a low viscosity index (Dean and Davis). The high molecular fractions are rather strongly unsaturated and cyclic.The authors have discovered a new method of polymerising ethylene or gases containing ethylene characterised by a high pressure polymerisation, working with a liquid diluent and using aluminum chloride as a catalyst combined with the action of nickel or nickel alloys.The temperature at which this process is carried out lies below 100° C; 70 to 80% of the reaction product consists of lubricating oil fractions, which have a viscosity index of 70 to 100.The velocity of the process is high, while the temperature at which it is carried out, is low.
The vitamin‐C content of blood and cerebro‐spinal fluid
Authors: Booij J. 
Published: September 2010

AbstractThe significance of vitamin‐C as a metabolism catalyst is briefly discussed.The distribution of ascorbic acid in blood and brain fluids has been investigated, the determinations being carried out simultaneously.The opinion of Plaut and Bülow, that the vitamin‐C content in the fluid decreases with age and must be considered as an indication of a diminished activity of the nerve fibres, could not be confirmed. When a smaller quantity of vitamin‐C is met with in older people, it must be connected with a small intake of food containing sufficient ascorbic acid.
Notiz zur Bereitung von Bleitetraacetat
Authors: Mendel H. 
Published: September 2010

AbstractDie in der Literatur angegebenen Vorschriften zur Bereitung von Bleitetraacetat führen zu Präparaten, die sich bei längerem Aufbewahren unter Braunfärbung zersetzen. Es wird eine Vorschrift mitgeteilt, mit der ein Präparat erhalten wird, das sich durch eine grosse Haltbarkeit aus‐zeichnet.
On the determination of aneurin in urine by the thiochrome method
Authors: Jansen B. C. P. , Westenbrink H. G. K. 
Published: September 2010

AbstractThe thiochrome method and its application to urine, as it is now carried out in our laboratory after three years experience, is discussed. A comparison is made of our method with a modification, in which adsorption of aneurin on franconite, previous to oxidation, is dispensed with.
On the existence of the compound Al2O3. 2 SiO2. 2 H2O
Authors: van Nieuwenburg C. J. , Koppers H. H. 
Published: September 2010

AbstractBy measuring the equilibrium vapour pressures at 380° of solid phases ranging from Al2O3. 2 SiO2. 1,8 H2O to Al2O3. 2 SiO2. 2,3 H2O, the existence of the dihydrate has been proved.
Investigations into the isomerisation of aliphatic and alicyclic hydrocarbons
Authors: Schuit G. C. A. , Hoog H. , Verheus J. 
Published: September 2010

AbstractWith the aid of our own measurements and values obtained from the literature, we tried to plot the position of equilibrium in the systems n‐butane ⇄ isobutane, n‐pentane ⇄ isopentane and methylcyclopentane ⇄ cyclohexane as a function of the temperature. The values found for the two last‐mentioned systems are in fair agreement with the values for ΔH0 and ΔS0, calculated on the basis of calorimetric measurements, but those for n‐butane ⇄ isobutane deviate considerably.Measurements of our own and literature data on the isomerisation equilibria of n‐butene, n‐pentene and cyclohexene have been considered in relation to the results for the alkane and cyclo‐alkane isomerisation.Furthermore results are reported of the isomerisation of hexane (at the equilibrium at 80° C chiefly methylpentane and to a less extent dimethyl‐butane were found to occur), methylcyclohexane (which at 80° C was isomerized only to a slight extent, chiefly 1,2‐ and 1,3‐dimethylcyclopentane being formed), and 1,1‐dimethylcyclohexane (at 80° C hardly any formation of five‐ring naphthenes, converted chiefly to 1,3‐, 1,4‐ and 1,2‐dimethylcyclohexane).
Synthèse de Quelques Dérivés du Thiophène
Authors: Backer H. J. , Stevens W. 
Published: September 2010

AbstractEn faisant condenser le thiodiacétate d'éthyle avec quelques α‐dicétones, l'acétylbenzoyle, la furile et la p.tolile, les auteurs ont obtenu des dérivés de thiophène, substitués en position 3 et 4.
Sur les Réactions Simultanées du Type
Authors: Korvezee A. E. 
Published: September 2010

AbstractOn a représenté dans un triangle équilatéral A B C les concentrations relatives de trois substances A, B et C. Si ces substances peuvent chacune se transformer dans les deux autres, les concentrations varieront suivant des courbes y = f(x). Cette fonction a été calculée et l'allure de ces courbes a été décrite pour le cas général où dans l'équilibre les concentrations des trois substances sont mesurables. J'al admis que toutes les réactions‐sont monomoléculaires et que dans l'équilibre il n'y aura pas de réaction cyclique.
The preparation of pyridine derivatives from bromopyridines by means of the Grignard reaction. II
Authors: Proost W. , Wibaut J. P. 
Published: September 2010

Abstract2‐bromopyridine is made to react with magnesium, with ethyl bromide as auxiliary reagent. The reaction product obtained, which contains pyridylmagnesium bromide in some form or other, is allowed to react with acetophenone, benzophenone or ethyl benzoate with the formation of: phenylmethyl‐(2‐pyridyl)‐carbinol, diphenyl‐(2‐pyridyl)‐carbinol or phenyl‐bis‐(2‐pyridyl)‐carbinol, respectively.In a similar manner from 2.6‐dibromopyridine via a dimagnesium compound and a subsequent reaction with benzaldehyde, 2,6‐bis‐(phenylhydroxymethyl)‐pyridine is obtained.
L'action de L'acide Borique 0.5 Molaire sur la Conductibilité Électrique des Acides Naphtol‐Orthocarboniques 2.3, 2.1 et 1.2
Authors: Böeseken J. , Niks A. 
Published: September 2010

AbstractLes acides phénol‐orthocarboniques provoquent une augmentation considérable de la conductibilité électrique de l'acide boriqueJ. Böeseken, Rec. trav. chim. 40, 574 (1921).
), ce qui s'accorde avec la formation de complexes avec cet acide. M. Meulenhoff a isolé un certain nombre de sels de l'acide disalicyloborique, e.a. le sel de strychnine, qu'il a dédoublé en ses composants optiquement actifsVersl. Akad. Wetenschappen Amsterdam 26, 32, 97 (1923); J. Meulenhoff. Proefschrift Delft, 1924.
).Nous nous attendions à ce que les acides naphtol‐orthocarboniques accusassent la méme propriété; or au contraire, l'acide naphtol‐2‐carbonique‐3 fut influencé par l'acide borique 0.5 molaire en sens négatif; les isomères 2.1 et 1.2, il est vrai, subissaient une augmentation de la conductibilité, mais seulement lorsque les concentrations n'étaient pas trop diluées. Nous avons pu démontrer que cette conduite anormale est due à deux causes; 1° la concentration restreinte des acides dans la solution demi‐molaire de l'acide borique, 2° l'ionisation très grande des acides naphtol‐carboniques. La première cause amènera un excès prononcé de l'acide borique, de sorte qu'en vertu des équilibres:magnified imageles solutions examinées contiennent presqu' exclusivement les acides monodiolboriques (I). Ces acides perdront aisément une molécule d'eau, se transformant ainsi en substances neutres (III):magnified imageLa deuxième cause, l'ionisation très grande des acides naphtol‐carboniques dans de l'eau pure, provoque dans ce véhicule une conductibilité électrique considérable. En remplaçant l'eau par de l'acide borique 0.5 molaire, on transforme les acides naphtol‐carboniques en acides mono‐diol‐boriques, qui se décomposent partiellement (III) sous perte d'ions d'hydrogène, d'où diminution de la conductibilité.En examinant les solutions plus concentrées, et nommément les acides naphtol‐orthocarboniques 2.1 et 1.2, on peut atteindre le domaine des acides di‐diol‐boriques (II), qui, ne pouvant se transformer en substances neutres, et étant plus forts encore que les acides naphtol‐carboniques eux‐mêmes, provoquent conséquemment une augmentation de la conductibilité.Les trois acides forment sans aucune doute des borocomplexes, étant donné qu'ils sont plus solubles dans de l'acide borique 0.5 molaire que dans de l'eau; de plus, nous avons isolé les sels de diméthylaniline des acides di‐(naphtyl carbino‐) boriques 2.3 et 2.1.La conduite négative des acides méconique et chélidonique envers l'acide borique 0.5 molaire, trouvée par M. Verkade ‐ anomalie également constatée chez les acides α‐cétoniques en solution diluée ‐ peut s'expliquer par le même raisonnement, tous ces acides étant très forts et, par rapport à ceux étudiés par M. Verkade, relativement peu solubles.
The heat of mixing of non‐polar liquids
Authors: Staverman‐Pekelder C. J. H. , Staverman A. J. 
Published: September 2010

AbstractWhen we suppose that the cohesion energy of liquids consists of three parts, orientation energy, induction energy and dispersion energy, an appreciable positive heat of mixing of two liquids can appear only when both liquids consist of polar molecules. Accounts may, however, be found in the literature of mixtures of non‐polar molecules, which are formed under development of heat.In some of these cases the heat of mixing is computed from the trend of miscibility with temperature by means of a thermodynamic relation. It is shown that in these cases the computed quantity is no real caloric effect.In two cases the heat of mixing is measured directly. These measurements have been repeated carefully, and determinations have been made of the contraction upon mixing. The conclusion drawn from these experiments is that the development of heat in these cases can be explained by assuming that the molecules in the mixture fit together somewhat better than in the pure liquids.
Untersuchungen über Pilzfarbstoffe XIII: Über Phomazarin, den Farbstoff von Phoma terrestris Hansen. I.
Authors: Kögl F. , Sparenburg J. 
Published: September 2010

AbstractAus Kulturen von Phoma terrestris Hansen wurde ein krystallisierter, rotgelber Farbstoff der Zusammensetzung C19H17O8N isoliert. Diese in der Natur bisher nicht angetroffene chinonartige Verbindung leitet sich von einem heterocyclischen Ringsystem der Formel C13H9N ab.