Slow magnetic relaxation in a Co(ii) octahedral–tetrahedral system formed of a [CoL3]2+ core with L = bis(diphenylphosphanoxido) methane and tetrahedral [CoBr4]2− counter anions

A bimetallic Co(ii) compound [Co(dppmO,O)3][CoBr4] consisting of cationic octahedral and anionic tetrahedral units shows a sizable magnetic anisotropy and field-supported slow magnetic relaxation with the relaxation time τ = 0.1–0.3 s at T = 1.9 K.

IDENTIFIKASI GUGUS FUNGSI DAN KANDUNGAN MINERAL LEMPUNG PACITAN DENGAN SPEKTROSKOPI INFRA RED (IR) X-RAY DIFFRACTION (XRD)

Clay is natural mineral from silicate family like crystal which has approximately 2 micrometer. There are two component unit of atom in clay mineral. One consists of oxygen or hidroksida with alumunium, iron or magnesium that coordinated in octahedral system. Others, it is tetrahedral system from silicon with oxygen or hidroksida. Based on IR analysis, it can be known that metal─OH bending vibrations it can be seen at 912,3 cm─1 wavelength. On the other bands between 694,3 and 754,1 cm─1 that are Si─O bending vibrations. X-Ray Diffraction (X-RD) analysis be seen main peak at 2 = 5,70o (d001=15,48 Å) and 2 = 20,02o (d001=4,43 Å). That are for smectite mineral kind montmorillonite as main unit in clay from Pacitan

The “Short Step Backward”

In 1922, Harry Fielding Reid, a founder of American seismology, encapsulated the American perspective on scientific method in a review of Wegener’s Origin of Continents and Oceans. “There have been many attempts to deduce the characteristics of the Earth from a hypothesis,” he wrote, “but they have all failed. There is the pentagonal system of Elie de Beaumont, the tetrahedral system of Green . . . [continental drift] is another of the same type.” The history of hypothetico-deductive reasoning in geology was a history of failure; progress was to be made another way. “Science has developed,” Reid concluded, “by the painstaking comparison of observations and, through close induction, by taking one short step backward to their cause; not by first guessing at the cause and then deducing the phenomena.” An obvious reading of Reid’s comment is that Wegener’s faulty methodology led him to faulty conclusions. No doubt Reid thought so. But another reading is the implicit suggestion that a different approach —a different presentation —might have elicited a more favorable response. Charles Schuchert’s comment that it was “wrong lor a stranger to the facts to generalize from them to other generalizations” suggested that if evidential support for drift could come from someone who was not a “stranger to the facts,” then Americans might be more disposed to entertain the theory. This thought had occurred a few years earlier to Reginald Daly and Frederick Wright. When Daly and Wright returned from South Africa in the autumn of 1922, each pondered the question of continental drift. Daly, whose proclivities ran to theory, developed a mechanical account of drift; Wright, an experimentalist, began to think about a possible test. The key empirical evidence was the alleged similarities between the Karroo formations in South Africa and age-equivalent rocks elsewhere in the world — evidence that had earlier motivated Suess’s idea of Gondwanaland and now supported Wegener’s theory of drift. But how similar were these rocks, really? Suess and Wegener had based their ideas on compilations of published literature; neither man had studied any of these rocks in person. In fact, there had never been a direct comparative study of the so-called Gondwana beds.

Conditions for the existence of potassium antimonates with a M(I): Sb ratio greater than one

During a solubility study on the ternary system KOH-KSbO3-H2O, a method was found for the preparation of the crystalline (X-ray active) compound KSbO3.2.3 H2O and a new compound, K4Sb2O7.(5.6-5.8) H2O, was discovered. Both of these substances and an anhydrous substance with composition K4Sb2O7 crystallize in the tetrahedral system. Their constitution was characterized on the basis of their IR spectra.

Distribution Function and Angular Deformations of a Model Related to Vitreous Ice and Liquid Water

A random tetrahedral model, without bonding defects and in which the distance between nearest neighbors is constant, has been constructed to study the effect of angular variations from tetrahedral, and the observations have been interpreted in terms of vitreous ice and liquid water. The model was constructed to have relatively small deformations from tetrahedral, and the oxygen–oxygen–oxygen angles vary from 90 to 132°, with an interquartile width of 12°. The measured density is intermediate between that of hexagonal ice and liquid water and, because of the small angular deformations, provides an estimate both of the density of vitreous water and of the minimum density possible for a random tetrahedral system.

A self-consistent field for methane and its applications

An approximate self-consistent field for methane has been obtained by first averaging the proton distribution over all orientations so as to obtain a spherically symmetrical field due to all the nuclei. The eight-electron problem then presented was solved by the usual self-consistent field method without exchange. Rapid convergence to self-consistency was found by using as initial approximations the charge distributions given by Coulson for the two-quantum orbitals of the tetrahedral system, averaged over all orientations. The self-consistent wave functions are used to calculate the charge distribution, energy, diamagnetic susceptibility and polarizability of the molecule and also the van der Waals forces between two molecules. The scattering of slow electrons by the self-consistent field obtained is also investigated in detail and compared with observations of total collision areas and angular distributions for methane. The observed similarity of behaviour between argon and methane in scattering slow electrons is reproduced by the theory provided the same approximation of using the self-consistent field without exchange is employed for each. Comparison of observed and calculated values of the quantities investigated indicate that the methane field is little less satisfactory than the corresponding fields for atoms.