The thermal decomposition of a fibrous talc was studied by transmission electron microscopy (TEM) and selected-area electron diffraction (SAD). Small changes in the lengths of a and b unit-cell parameters were noticeable at 500°C, but the talc laths did not change morphologically until 800°C. At this temperature striations began to appear in the TEM image, and the talc SAD reflections began to develop faint satellite streaks. At 900°C the striations appeared to be crystallites, and reflections of orthorhombic enstatite were noted. Both TEM and SAD evidence showed that the enstatite crystallites were formed in three orientations corresponding to the three pseudohexagonal a axes of the talc. Thus, triple superposition of the electron diffraction pattern at the three equivalent angles explains the high symmetry star-shaped pattern. At 1000° to 1100°C the enstatite crystallites were shorter and thicker, and the streaks in the SAD pattern were nearly absent. Above 1200°C only one orientation of the enstatite crystallites was found. Noncrystalline regions were also detected at 900°C and became progressively scarce at 1000° and 1100°C. They were not detected at 1200°C. At 1300°C cristobalite was detected in some SAD patterns. The crystallographic axes and unit-cell parameters of the talc and enstatite were also topotactically related as follows: at (5.3 Å)//ce (5.2 Å); bt (9.16 Å)//be (8.8 Å); d(001)t (18.84 Å)//ae (18.2 Å). These results are compatible with an inhomogeneous decomposition mechanism as proposed by earlier workers.

The notorious but: unimpeachably corroborated case of Pavlov's mice raises, in capsule form, a variety of fascinating issues with far-reaching ramifications in several directions, but with particularly serious implications, several of which are well worth restating and pondering further (cf. Sebeóle 1977b: 192-201), both for the foundations and research methodology of contemporary semiotics.

Hydroxide and oxyhydroxide products of aluminum were formed at room temperature at an initial Al concentration of 2 × 10-3 M, pH 8.2, and at varying concentrations of organic and inorganic ligands commonly found in nature. The effectiveness of the ligands in promoting the formation of noncrystalline products over crystalline Al(OH)3 polymorphs was found to be in the following order: phthalate ≅ succinate < glutamate < aspartate < oxalate < silicate ≅ fluoride < phosphate < salicylate ≅ malate < tannate < citrate < tartrate. The lowest ligand/Al molar ratio at which the production of Al hydroxides or oxyhydroxides was inhibited ranged from 0.02 to 15. Above critical ligand/Al ratios, crystalline products were inhibited and ligands coprecipitated with noncrystalline products which remained unchanged for at least 5 months. Polydentate and large ligands generally were more inhibitive than those with fewer functional groups or of smaller size.

The perturbing ligands promoted and stabilized the formation of pseudoboehmite over crystalline Al(OH)3 polymorphs in the following sequence: chloride < sulfate < phthalate ≅ succinate < glutamate < silicate < aspartate < phosphate < salicylate ≅ malate < tannate < citrate < tartrate. The optimal range of the ligand/Al molar ratios for the formation of pseudoboehmite varied, for example, from 0.005–0.015 for tartrate to 600–1000 for chloride. Pseudoboehmite was not formed in the presence of fluoride.

The consequences of legal access to medical marijuana for individuals' well-being are controversially assessed. We contribute to the discussion by evaluating the impact of the introduction of medical marijuana laws across US states on self-reported mental health considering different motives for cannabis consumption. Our analysis is based on BRFSS survey data from close to eight million respondents between 1993 and 2018 that we combine with information from the NSDUH to estimate individual consumption propensities. We find that eased access to marijuana through medical marijuana laws reduce the reported number of days with poor mental health for individuals with a high propensity to consume marijuana for medical purposes and for those individuals who likely suffer from frequent pain.

The adsorption of D-glucosamine (2-amino-2-deoxy-D-gIucose) in the protonated or neutral form on homoionic Cu2+-bentonite was investigated by infrared (IR) and electron spin resonance (ESR) spectroscopy and chemical analyses of solution. The results show that the interaction of the glucosamine hydrochloride with the clay complexed a small fraction of interlayer metal ions with neutral amino sugar molecules. In contrast, the adsorption of free glucosamine was much more favorable and resulted in interlayer copper(II) complexes, mainly those in which the ligand was coordinated through amino and deprotonated hydroxyl groups. Part of the amino sugar molecules, however, were transformed into glucosammonium, replacing copper as the saturating ion.

Recently, a renewed history of foreign immigration in Italy, focusing on the very first migration flows after the Second World War, has offered a more appropriate periodisation of the phenomenon. Women have been at the forefront of these flows, which were initially determined by the new postcolonial setting of the former Italian colonies (Eritrea, Somalia and Ethiopia). Subsequently, the immigrants came from various other countries (Spain, Cape Verde, Portugal, El Salvador, Peru, Philippines, Sri Lanka, Ceylon, India, Bangladesh, Pakistan). At the same time, the majority of them were employed in a specific sector of the labour market: domestic work. This article focuses on female immigrants who were employed as domestic workers, their presence in public discourse in Italy in the 1960s and 1970s, and government policies in this area. Drawing on statistical data and surveys, press and audiovisual materials, and feminist theory and practices, it aims to analyse the construction of paradigms – visibility, invisibility, subalternity, rights and racialisation – associated with female immigration and domestic work as a specific sector of employment.

This is how Montaigne explains the principles which he followed in his role as mayor, a statement whose very expression casts all the light needed on the nature of what has been called Montaigne's conservatism. In Montaigne's political language, to conserve is defined by its opposition to innovate. Conservation receives its lexical “value” from its contrasting relation with innovation and with “novelties.” This semantic pair, common in sixteenth-century French and in most European languages, is profoundly different from the present system. In today's language, the concept of conservatism (itself of recent formation) is defined principally in terms of the notion of progress or (because of the symmetry of the suffixes) of progressionism, in the sense which it had taken on during the 18th century, but the antonym innovation has not ceased contributing to the “value” of conservation. Today's semantic system cannot avoid attributing to “conservatism” an essentially antithetic function in reference to historic “progress,” or to theories of progress in which innovation is generally seen in a favorable light.

The ferrous iron content of two vermiculitized biotites decreased by treatment with 0.1 N salts of copper at 70°C from 9.1–14% to 1.8–2.6%. Presumably, interlayer copper ions acted as a catalyst (here, an electron carrier) for the oxidation of iron by dissolved oxygen. The oxidized iron was ejected from the structure and formed crystalline iron minerals, such as hematite and goethite. Weight loss determinations, chemical, and X-ray powder diffraction data suggest that Cu(II) ions were polymerized to hydroxy-hydrous compounds in the interlayer space. Poor exchangeability of the resultant complex is attributed to the formation of strong electrostatic attractions between OH groups of the interlayer complexes and silicate oxygens.

Mineralogical weathering sequences in sediments overlying lignite beds were investigated in a core (27 m deep) from Calvert, Robertson County, northeast Texas. Weathering trends were evaluated based on the properties and relative distributions of both the expandable and non-expandable minerals. The sulfide minerals in these sediments are the most susceptible to weathering and were only observed in the unaltered (reduced) zone below 7 m. Oxidation of the sulfides has resulted in the formation of jarosite and gypsum in the upper 7 m of the core (oxidized zone). The oxidized zone is further characterized by reddish brown colors (high chroma), a greater quantity of dithionite-extractable iron, and absence of chlorite. Although the major clay minerals in these sediments (smectite, kaolinite, mica) are largely detrital, weathering has resulted in an increase in the content of kaolinite and a decrease in the content of mica towards the surface. The mica appears to have altered to a high-charge smectite characterized by basal spacings of 32 Â after intercalation with octadecylammonium cations. The high-charge smectite is most abundant in the soil horizons at the top of the core and gradually decreases with depth. A low-charge smectite is the most abundant species in the un weathered parent sediments and increases with depth. Key Words—Lignite, Oxidation, Reclamation, Smectite, Soil, Weathering.

The presence of women in possession cults has frequently been noted. Thus women are usually the priviliged religious participants in Haitian Voo-doo and in the African Bori Hausa. Even allowing for the distinction of whether the role of religious chief is held by a male or a female, it seems women are in the majority in the cases representing almost the totality of those cultists who fall into a trance. In this article we propose to compare the position of women within two possession cults in Brazil. One, Candomblé is of African origin; the other, Umbanda, is a synthesis of African religions, Catholicism, and the spiritism of Allan Kardec. We shall attempt in each case to associate the religious position of women with the social position they exercise in each society.

Triclinic IIb-4 and monoclinic IIb-2 clinochlore polytypes from Kenya are intergrown laterally in (001) platelets and are separated optically in some places by sharp lines of demarcation and in other places by embayed boundaries. Electron microprobe analyses show no compositional differences between the two polytypes. Structural refinements of each show that the 2:1 layer is identical in the two structures with no tetrahedral or 2:1 octahedral cation ordering in either ideal or subgroup symmetries. The two interlayer sheets dilfer only in the distribution of A1 and Mg over interlayer sites M3 and M4, but not in the distribution of Fe3+, Fe2+, or vacancies. The monoclinic IIb-2 polytype is less ordered than the triclinic IIb-4 polytype. The mean M-O,OH bond length of 1.990 Å indicates significantly less of the smaller A1 present in the M4 site of IIb-2 than for the mean M-O,OH value of 1.957 Å for the M4 site of IIb-4. The textural relations and the structural refinements suggest that the monoclinic IIb-2 structure is inherently less stable than the triclinic form. This is in accord with the observed lesser abundance in nature of the monoclinic form.

A program of simultaneous linear equations has been developed to calculate component proportions and/or component property values for mineral mixtures in soil clays and sediments. The analysis is based on quantitatively measured chemical and physical properties of samples and involves (1) qualitative identification of the mineral components in the mixture by any appropriate means; (2) quantitative measure of the sample property values selected for use in the program; (3) estimation of the proportion of each component in the mixture by a technique such as X-ray powder diffraction; (4) assignment of limits to component property ranges; (5) selection of one of four available calculation options and application of the simultaneous linear-equations program; (6) examination of the residuals of the analysis and, if appropriate, adjustment of the initial estimates for component proportions or property ranges and then repeating step 5; and (7) verification of the final component proportions by comparison with information from step 1. Completeness and/or accuracy of the final results for component proportions may be checked by the closeness of approach to 1.0 for the sum of the component proportions. The method requires that, at minimum, the number of properties measured must equal the number of components in the samples being analyzed and that the minimum number of samples must equal the number of properties measured.

Using the clay fractions of 15 Pennsylvania soils containing kaolinite, illite, smectite, vermiculite, chlorite, interstratified vermiculite/chlorite, quartz, and noncrystalline material, and measuring methylene blue cation-exchange capacity, the amount of Ca displaced by Mg from a Ca-saturated clay, the amount of K displaced by NH4 from a K-saturated clay heated to 110°C, % K2O, % SiO2, % MgO, and weight loss at 110°–300°C and 300°–950°C, the adjustment of property values was found to have the lowest residual value and the most consistent results. The source of analytical errors was also located by examination of residual tables. Samples that were similar in composition gave more reliable component proportions.

Sorption and desorption of two neutral, nonpolar organic compounds, 1,2-dibromoethane (EDB, a soil fumigant) and trichloroethene (TCE, an industrial solvent and common ground-water contaminant), by pyrophyllite, kaolinite, illite, and smectite were investigated. For sorption, vapors of the compounds in a stream of dry N2 gas were passed through columns of the powdered clay minerals for different periods of time. The compounds retained by the clays were extracted with methanol and analyzed by gas chromatography (GC). For desorption, N2 was passed through the treated samples, and the desorbed compounds were collected in hexane traps and analyzed by GC.

Initially sorption was rapid for several hours but then proceeded at a slower rate for many hours. Surprisingly, the clays sorbed large quantities of these neutral compounds; for example, the pyrophyllite, kaolinite, illite, and smectite sorbed about 3, 5, 6, and 9% EDB, respectively, by weight. The amounts of TCE sorbed, which is more volatile than EDB, were somewhat less. Only a portion of the compounds sorbed over a period of time were desorbed in the same period of time. Desorption was rapid initially but then proceeded at a slow rate; slow desorption continued for over 100 hr from samples which had undergone sorption for only 1–2 hr. A two-compartment efflux model was used to describe the sorption behavior. A rapidly desorbing component was considered to be present on the outer surfaces of the clay aggregates and a slowly desorbing component, in the interior pores of the aggregates.

The ardent antagonism between two aesthetic parties, figuration and abstraction, which for more than half a century has stamped art history in old Europe, with increasingly overlapping implications for youthful America, Japan and many other places, today tends to reduce itself to being simply the anecdotal imprint of an era: in the final analysis it seems already condemned to disappear in favor of a notion of complementarity and even synthesis.