Fundamental IR Research Articles

Multicomponent Analysis of Meat Products

A new method for rapid multicomponent analysis of meat products is reported. The sample is homogenized, and then dispersed by treatment with an alkaline aqueous solution combined with mechanical subdivision. Constituents are determined by infrared transmission spectrophotometry in the fundamental IR absorption bands. It is possible to measure protein, fat, and carbohydrate in about 5 min with an accuracy and precision comparable to that of well established standard methods, and no expensive or dangerous chemicals are used.

Principles and practice of near infra‐red (NIR) reflectance analysis

SummaryNear infra‐red (NIR) analysis is now widely used for the rapid analysis of many agricultural and food products for protein, moisture, oil, starch, sucrose, fibre, grain texture and lysine. Research has shown that the technique can also be used for the prediction of malting quality of barley, baking quality of wheat and measurement of the degree of starch damage in flour.The technique of NIR analysis uses very small differences in absorption of NIR radiation at wavelengths corresponding to overtones and combinations of fundamental IR frequences of chemical functional groups that are characteristic of particular analytes. Complex regression mathematics is used to transform these absorption measurements into an analytical result.

Application of the ν D/ν H ratio to the assignment of C-H(D) and ring vibrations in the infrared spectra of imidazole and its deuterated analogues

The IR spectra (4000-150 cm −1)of imidazole and its I-, 2,4,5- and 1,2,4,5-deuterated analogues are discussed. All twenty-one fundamental IR active imidazole vibrations are assigned by employing the ν D/ν H ratio which is defined as the ratio between the frequencies of corresponding IR bands in the spectra of a ring-deuterated heterocyclic (or aromatic) molecule and its normal analogue. The results suggest that some previously reported assignments require revision.

The infrared absorption spectrum and the inversion degree of manganese ferrite

Infrared spectra of MnFe 2O 4 with inversion degrees of 0.05 and 0.2 are reported. It can be concluded that the absorption observed at 335 cm −1 has to be the third fundamental IR active mode.

Shock Tube Vibrational Relaxation Measurements: N2 Relaxation by H2O and the CO–N2 V–V Rate

Shock tube measurements of the rates of vibrational relaxation of N2 by H2O and the vibrational exchange between N2 and CO are described. Simultaneous measurements of H2O v2 ν2 band and CO fundamental band ir emission were performed in mixtures of 1%–10% CO+∼1% H2O+N2. Measurement of H2O emission by a calibrated optical system allowed an accurate determination of the concentration of H2O for each run. The CO emission had two, almost decoupled, regions of behavior which allowed determination of two relaxation times: Pτ NCe≈ 1.6 atm· μsec (V–V exchange relaxation time between N2 and CO) and Pτ NH≈ 1.5 atm· μsec (T–V relaxation of N2 by H2O), both for 960 〈T〈2200°K.

Etude de composés d'addition d'acides de Lewis. XXXVI [1] Composés d'addition de l'anthraquinone‐9, 10 et de l'anthrone avec divers acides de Lewis

AbstractSolid stoichiometric adducts of 9, 10‐anthraquinone with SbCl5, ZrCl4, TiCl4 SnCl4, AlCl3, have been prepared. The very important lowering Δω of the IR. carbonyl frequency, ranging from −175 cm−1 for SbCl5 to −117 cm−1 for SnCl4, shows that the acceptor is linked by a dative bond to the carbonyl oxygen atom acting as a donor; an assignment of most of the fundamental IR. frequencies is proposed for anthraquinone and the mentioned adducts.Similar assignments and interpretation have been made for anthrone and its solid adduct with SbCl5, ZrCl4, TiCl4, SnCl4, AlCl3 and ZnCl2, where the CO lowerings range from −164 cm−1 for SbCl5 to −97 cm−1 for ZnCl2.

IR intensities in CHCL 3 and CDCL 3

The integrated intensities of the fundamental ir absorption bands of CHCl 3 and CDCl 3 have been measured using the pressure-broadening technique. These intensities are interpreted in terms of displacement polar tensors, which give the change of the dipole moment of the molecule due to a set of displacements of their atomic nuclei. The components of these polar tensors for the nuclei of both molecules have been calculated for all the possible combinations of the signs of the dipole moment derivatives with respect to the normal coordinates. By comparing the results for both molecules and for CHF 3 and SiHCl 3, the most satisfactory choice of signs has been decided. Calculations of integrated intensities from recorded spectra and of displacement polar tensors from these intensities, have been carried out in a 7070-IBM computer, for which several programmes have been written.

Synalbumin Insulin Antagonism in Idiopathic Hypoglycemia of Infancy

Infantile idiopathic hypoglycemia appears to be an early manifestation of an early manifestation of an inherited metabolic defect that leads to diabetes mellitus. Eight children with this form of hypoglycemia were studied for the presence of synalbumir insulin antagonism. All had diabetes in one or both parenta families. Two of the children had normal antagonist level. before and after they developed chemical diabetes. A thirt child was tested twice after she was found to have chemica diabetes, and on each occasion had normal antagonist levels. Rather than a causa sine qua non for the develop ment of diabetes, or a constant feature of the disorder, ex cess synalbumin insulin antagonism appears to be a variable expression of a more fundamental metabolic abnormality ir essential diabetes mellitus.

On the Holonomy Group of Locally Euclidean Spaces

Part I of this paper is devoted to giving an algebraic characterization of the fundamental group of a compact locally euclidean manifold (i.e. a compact riemann manifold with curvature and torsion tensors identically zero). If M is a compact locally euclidean manifold then the fundamental group ir of M may be considered as a subgroup of the group of rigid motions, R(n), of n-dimensional euclidean space, En, and the orbit space of xr acting on En, E /Xr, is homeomorphic to M. Bieberbach in [3] showed that if N denotes the subgroup of ir consisting of pure translations then 1. N is a free abelian group generated by n linearly independent translations. 2. FIN is a finite group. Now it is clear from the discussion in [1], that in/N is isomorphic to the holonomy group, H, of M as a riemann manifold. Also, since E'/I is a manifold, we must have 'r operating on En without fixed points. This is equivalent, assuming 1 and 2, to 3. in has no finite subgroups. To see that 7r can have no finite subgroups, we may use the P. A. Smith Theory or an elementary argument on convex sets, since we have linear transformations. The converse will be established later. In Theorem 1 we prove that a finitely generated group in is isomorphic to the fundamental group of some compact locally euclidean manifold if and only if there exists a normal subgroup N c ir which is maximal abelian (contained in no larger abelian group), where N is free on n generators, and satisfies conditions 2 and 3 above. In the second part of this paper, we will show that any finite group can be the holonomy group of a compact locally euclidean manifold. We will actually show the following: Let G be a finite group and let F/R = G, where F is a finitely generated free group and F and R are non-abelian. Then if Fo = F/[R, R] and Ro = R/[R, R], where [R, R] denotes the commutator subgroup of R, then Fo/Ro = G and Fo is isomorphic to the fundamental group of a compact locally euclidean manifold. We give an example to show that the converse is not true. The authors would like to take this opportunity to thank M. Auslander and A. Rosenberg for their suggestions and advice during the writing of this paper.