The crystal structures of two members of the solid solution series Mg(OH) x Cl y x+y = 2, Mg(OH) 1.7 Cl 0.3 (P3m1, a = 3.169(2) Å, c = 5.530(12), V = 48.1(1) Å 3 at T = 365°C) and MgOHCl (R3m, a = 3.3877(4) Å, c = 17.534(4) Å, V = 174.27(6) Å 3 at T = 625°C) were determined from in situ synchrotron powder diffraction data at high temperature upon dehydration of 3Mg(OH) 2 ·MgCl 2 ·8H 2 O (F3) and
The metastable phase 9Mg(OH)(2)·MgCl(2)·4H(2)O (9-1-4 phase) was found at the extended metastable isotherm of Mg(OH)(2) in the system MgO-MgCl(2)-H(2)O at 120 °C and occurs as intermediate binder phase during setting of magnesia cement due to temperature development of the setting reaction. The crystal structure of the 9-1-4 phase was solved from high resolution laboratory X-ray powder diffraction data in space group I2/m (C2/m) (a = 22.2832(3) Å, b = 3.13501(4) Å, c = 8.1316(2) Å, β = 97.753(1)°, V = 562.86(2) Å(3), and Z = 1). Structural and characteristical relations of the phases in the system MgO-MgCl(2)-H(2)O can be derived, with which the development of the cement or concrete qualities becomes explainable.
Using a behavioral paradigm designed to simulate olfactory-guided foraging, the ability of five squirrel monkeys to distinguish iso-amyl acetate from n- and iso-forms of other acetic esters (ethyl acetate to decyl acetate) and from other esters carrying the iso-amyl group (iso-amyl propionate to iso-amyl capronate) was investigated. We found (i) that all five animals were clearly able to discriminate between all odor pairs tested; (ii) a significant negative correlation between discrimination performance and structural similarity of odorants in terms of differences in carbon chain length of both the aliphatic alcohol group and the aliphatic acid group of the esters; and (iii) that iso- and n-amyl acetate were perceived as qualitatively similar despite different steric conformation. Using a triple-forced choice procedure, 20 human subjects were tested on the same tasks in parallel and showed a very similar pattern of discrimination performance compared with the squirrel monkeys. Thus, the results of this study provide evidence of well-developed olfactory discrimination ability in squirrel monkeys for aliphatic esters and support the assumption that human and non-human primates may share common principles of odor quality perception.
Structure analysis using single-crystal diffraction was carried out as a contribution to the dispute about the nature of the water channel structure of bassanite (CaSO(4)·0.5H(2)O). A recent result of Weiss & Bräu (2009) for the crystal structure of bassanite (monoclinic, space group C2) at ambient conditions of air humidity was confirmed. In the presence of high relative air humidity the crystal structure of bassanite transformed due to the incorporation of additional water of hydration. The crystal structure of CaSO(4)·0.625H(2)O was solved by single-crystal diffraction at 298 K and 75% relative air humidity. The experimental results provided an insight into both crystal structures. A model explaining the phase transition from CaSO(4)·0.625H(2)O to CaSO(4)·0.5H(2)O was derived. The monoclinic cell setting of CaSO(4)·0.5H(2)O and the trigonal cell setting of CaSO(4)·0.625H(2)O were confirmed by powder diffraction.
The
solubility equilibria of the ternary system Mg(OH)2–MgCl2–H2O were determined at
temperatures from 298 to 393 K applying equilibration periods of up
to 3.5 years. As a result, four thermodynamically stable magnesium
chloride hydroxide hydrates (Sorel phases) exist in the ternary system
within the investigated temperature range. These are the 3-1-8 phase
[3Mg(OH)2·MgCl2·8H2O],
the 9-1-4 phase [9Mg(OH)2·MgCl2·4H2O], the 2-1-4 phase [2Mg(OH)2·MgCl2·4H2O], and the 2-1-2 phase [2Mg(OH)2·MgCl2·2H2O]. The also known 5-1-8 phase [5Mg(OH)2·MgCl2·8H2O] was found to
be metastable in the solid–liquid system. With this work, a
reliable solubility data set is now available, for example, to prove
the long-term stability of magnesia building materials in the presence
of salt-bearing media, a challenging demand on the material in a special
application as a barrier construction material in salt formation.
Two samples of pure NiCl(OH) were produced by hydrothermal synthesis and characterized by chemical analysis, IR spectroscopy, high‐resolution laboratory X‐ray powder diffraction and scanning electron microscopy. Layers composed of edge‐sharing distorted NiCl6x(OH)6−6x octahedra were identified as the main building blocks of the crystal structure. NiCl(OH) is isostructural to CoOOH and crystallizes in space group Rm [a = 3.2606 (1), c = 17.0062 (9) Å]. Each sample exhibits faults in the stacking pattern of the layers. Crystal intergrowth of (AγB)(BαC)(CβA) and (AγB)(AγB) [C6 like, β‐Ni(OH)2 related] stacked layers was identified as the main feature of the microstructure of NiCl(OH) by DIFFaX simulations. A recursion routine for creating distinct stacking patterns of rigid‐body‐like layers in real space with distinct faults (global optimization) and a Rietveld‐compatible approach (local optimization) was realized and implemented in a macro for the program TOPAS for the first time. This routine enables a recursive creation of supercells containing (AγB)(BαC)(CβA), (AγB)(AγB) and (CβA)(BαC)(AγB) stacking patterns, according to user‐defined transition probabilities. Hence it is an enhancement of the few previously published Rietveld‐compatible approaches. This routine was applied successfully to create and adapt a detailed microstructure model to the measured data of two stacking‐faulted NiCl(OH) samples. The obtained microstructure models were supported by high‐resolution scanning electron microscopy images.
In the course of investigations relating to magnesia cement the basic magnesium salt hydrates 2Mg(OH) 2 ·MgCl 2 ·2H 2 O (2-1-2 phase) and 2Mg(OH) 2 ·MgCl 2 ·4H 2 O (2-1-4 phase) were found as stable phases in the system MgO-MgCl 2 -H 2 O at a temperature of T = 120°C and were characterized by thermal analysis, Raman spectroscopy and X-ray powder diffraction. The crystal structures of the 2-1-2 and 2-1-4 phases were determined from high resolution laboratory X-ray powder diffraction data.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.