Chemical Formulas and Nomenclature

Chemical Formula and Nomenclature explains the rules for writing chemical formulas and naming compounds. The concept of oxidation number and how to determine it within a molecule or a polyatomic ion is described. Rules for writing and naming ionic and molecular compounds are discussed.

Orange Pickeringite from the Algares 30-Level Adit, Aljustrel Mine, Iberian Pyrite Belt, Portugal

The sheltered environment of the Algares +30 level adit (underground mine gallery) contributes to the preservation of secondary water-soluble minerals formed on the tunnel walls. The massive sulphide and related stockwork zone are hosted by the Mine Tuff volcanic unit and are exposed in the walls of the gallery, showing intense oxidation and hydrothermal alteration. Minerals from the halotrichite group were identified on the efflorescent salts, typically white fine-acicular crystals but also on aggregates with dark orange/brownish colour. Mineral characterization was performed using several methods and analytical techniques (XRD, XRF-WDS, SEM-EDS, DTA-TG), and the chemical formulas were calculated maintaining the ratio A:B ≅ 1:2 in accordance with the general formula of the halotrichite group, AB2(SO4)4·22H2O. This methodology allowed the assignment of the orange colour to the presence of trivalent iron on iron-rich pickeringite in partial substitution of aluminium.

Effects of Bi Substitution on the Cobalt-Free 60wt.%Ce0.9Pr0.1O2−δ-40wt.%Pr0.6Sr0.4Fe1−xBixO3−δ Oxygen Transport Membranes

The mixed ionic-electronic conducting (MIEC) oxygen transport membrane (OTM) can completely selectively penetrate oxygen theoretically and can be widely used in gas separation and oxygen-enriched combustion industries. In this paper, dual-phase MIEC OTMs doped with Bi are successfully prepared by a sol-gel method with high-temperature sintering, whose chemical formulas are 60wt.%Ce0.9Pr0.1O2−δ-40wt.%Pr0.6Sr0.4Fe1−xBixO3−δ (60CPO-40PSF1−xBxO, x = 0.01, 0.025, 0.05, 0.10, 0.15, 0.20). The dual-phase structure, element content, surface morphology, oxygen permeability, and stability are studied by XRD, EDXS, SEM, and self-built devices, respectively. The optimal Bi-doped component is 60wt.%Ce0.9Pr0.1O2−δ-40wt.%Pr0.6Sr0.4Fe0.99Bi0.01O3−δ, which can maintain 0.71 and 0.62 mL·min−1·cm−2 over 50 h under He and CO2 atmospheres, respectively. The oxygen permeation flux through these Bi-doped OTMs under air/CO2 gradient is 12.7% less than that under air/He gradient, which indicates that the Bi-doped OTMs have comparable oxygen permeability and excellent CO2 tolerance.

A ß-Secretase Modulator Decreases Tau Pathology and Preserves Short-Term Memory in a Mouse Model of Neurofibrillary Degeneration

Identifying which among several in cellulo pharmacological activities is necessary for the proper in vivo activity is essential for further drug development against Alzheimer’s disease pathophysiological processes. An in-depth structure–activity relationship–based study has been carried out, and two molecules, named MAGS02-14 and PEL24-199, that share a ß-secretase modulatory effect associated or not to a lysosomotropic activity in cellulo have been identified. In terms of chemical formulas, MAGS02-14 and PEL24-199 only differ from each other by a single nitrogen atom. The study aimed to elucidate the in vivo pharmacological effects of lysosomotropic and/or the ß-secretase modulatory activity in a tau pathology mouse model. To address this question, the THY-Tau22 transgenic model of tauopathy was treated with both compounds for 6 weeks in a curative paradigm. Short-term memory, tau burden, and inflammatory processes were analyzed using orthogonal methods, and PEL24-199, but not MAGS02-14, was shown to restore the short-term memory and reduce the neurofibrillary degenerating process. These effects were associated with a reduced phosphorylation of tau, an increased phosphatase expression, and decreased astrogliosis. Our results, therefore, suggest that the lysosomotropic activity may be nonessential for the effect on tau pathology.

Application of stoichiometric hydrogen atoms for balancing organic combustion reactions

Combustion is a common redox reaction, and organic combustion is one of the basic contents in chemistry curriculum. The transferred H-atom is commonly used as a redox indicator in organic chemistry and biochemistry. Nevertheless, the relationship between the number of transferred H-atoms and the number of transferred electrons has not been fully revealed. Oxidation number (ON) is an electron-counting concept. Without knowing the ONs, the number of transferred electrons cannot be counted and therefore, the redox reactions cannot be classified, defined, and balanced. This paper explores the new H-atom method for counting the number of transferred H-atoms. It provides a half-reaction approach to balance the overall organic combustion reactions. Only simple arithmetic procedures are needed to determine the number of transferred H-atoms and consequently the number of transferred electrons. According to this method, the mathematical formulas for assigning the number of transferred H-atoms can be deducted by balancing the general chemical formulas of organic compounds in half and overall organic combustions. Furthermore, the number of transferred electrons and their stoichiometric categories can be determined conveniently by any given organic chemical formula in organic combustion reactions.

Reversible Water Ad-/Desorption Behavior of a 3D Polycatenation Network, [Zn(bpp)(BDC)]·1.5(H2O), Constructed by 2D Undulated Layered MOF

A three-dimensional (3D) polycatenation supramolecular network with chemical formulas, [Zn(bpp)(BDC)]·1.5H2O (1), (bpp = 1,3-bis(4-pyridyl)propane, BDC2- = dianion of terephthalic acid), was synthesized and structurally determined. In compound 1, the coordination geometry of Zn(II) ion is distorted tetrahedral, where its 2D undulated layered framework is constructed via the bridges of Zn(II) ions with bpp and BDC2− ligands. Adjacent 2D layers are arranged in a combined parallel and interpenetrated manner to complete its 3D polycatenation supramolecular architecture. Compound 1 shows a one-step dehydration process with the weight losses of 6.1 %, approximately equal to the weight percentage of losing 1.5 guest water molecules. The cyclic thermogravimetric analysis reveals that compound 1 shows reversible, sponge-like water de-/adsorption behavior during de-/rehydration processes. Compound 1 also exhibits significant water vapor hysteresis isotherm.

Prototype Hermetic Teachings: Hermes Trismegistus and Three Hermes

The paper treats the topic of hermeticism — an esoteric tradition of teachings — with the view to its origins and varying interpretations. In setting research objectives, the text aims at identifying the common structural foundations of myths and ideas of the hermetic genesis and to establish the main vectors of the formation and transformation of esoteric teachings presented in the spiritual domain and reflected in the material culture of Western Europe from the 4th century BC to the present. For the needs of such a comparative study that embraces philosophical, religious and historical phenomena of culture, the following methods are used. As it is mostly the texts that are analyzed, the methodological framework consists of the interpretation of texts and artifacts – all along the line of presentation of historical sequences, of their recursion, of structural and functional aspects. The sources included not only texts, mathematical operations and chemical formulas of previously known alchemic artifacts are also introduced into the comprehensive analysis. The examination of cultural phenomena leads to the systematization of religious origins, historical and philosophical traditions and scientific achievements that underlie the formation of hermeticism. This structuralisation is possible due to the tools for the analysis of the hermetic body developed in this text. The mapping of the historical development of hermeticism is proposed in a three-level paradigm model based on the image of the Thrice-Great Hermes. It is concluded that the basis of the image of Hermes is the invariant of the historical three-level model of cognition of esoteric teachings, for descriptions of which the terms of ABC — paradigm are introduced. Each of the Hermea has own disciplinary paradigm. The first level of Hermes I, the author of cosmogonic visions, A — paradigm, is represented by inner visions (revelations of the cosmic mind or daimonic visions), thus forming the cultural level of mythology, theology. The level of Hermes II, the founder of writing and counting, lies in the realm of concepts of visions ‒ e.g. the Platonic philosophy, geometry, mathematics (B — paradigm). The third level (C — paradigm) is represented by texts and alchemical artifacts (Alexandrian crystal) of Hermes III, the founder of the art of healing and chemistry, that further embodied in empirical sciences, chemistry and astronomy, as well as ancient technological knowledge of the production of metals, glass and dyes. In general, all hermetic disciplines and practices emerge on the basis of this three-level paradigm.