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Not much is known from an ethnohistorical perspective about the use of psychoactive substances in southern Central America; it is mainly through the archeological record that their presence in the past has been inferred. This article reviews evidence for the use of mind-altering plants and mushrooms in the societies that inhabited the current Costa Rican territory during pre-Columbian times, and explores the cultural significance of this activity. Historical, ethnographic, archeological, and paleobotanical information was examined and integrated with the data obtained from the analysis of 46 artifacts with a presumed linkage to psychoactive drug use that were selected from an exhaustive search in the collections of the Museums of the Central Bank of Costa Rica and the National Museum of Costa Rica. Preliminary results suggest the consumption of tobacco (Nicotiana spp. L.), morning glory (Ipomoea spp. L.), cohoba [Anadenanthera peregrina (L.) Speg.], psychedelic fungi [Amanita muscaria (L.) Lam. and Psilocybe (Fr.) P. Kumm. species], as well as various alcoholic and invigorating beverages was present in ancient times. This use was likely connected to shamanistic healing practices, social–ceremonial events, and the ritual activities of people who held positions of religious and political importance within society.

Open access
Journal of Thermal Analysis and Calorimetry
Authors:
Silvia Prolongo
,
M. Burón
,
A. Salazar
,
A. Ureña
, and
J. Rodríguez

Abstract  

Blends based on epoxy resins and a random copolymer, poly(styrene-co-allylalcohol) (PS-co-PA) were studied, analysing the effect of epoxy nature. The epoxy cross-linking reaction was carried out by homopolymerisation, using an imidazole as initiator, and by addition of several amine hardeners. The imidazole acts as initiator of anionic epoxy etherification and as catalyser of epoxy-hydroxyl reaction. Important differences were observed on the network structure and phase behaviour of blends depending on the nature of epoxy matrix. These cause that the blends present different morphologies and different dynamic mechanical properties.

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Thermal study of unaltered and altered dolomitic rock samples from ancient monuments

The case of Villarcayo de Merindad de Castilla la Vieja (Burgos, Spain)

Journal of Thermal Analysis and Calorimetry
Authors:
J. L. Perez-Rodriguez
,
A. Duran
, and
L. A. Perez-Maqueda

Abstract

In this study, the decomposition behaviour of unaltered and altered dolomitic rock samples used in Cultural Heritage buildings was studied by simultaneous TG–DTA experiments at different atmospheres, X-ray diffraction in a high-temperature chamber, and evolved gas analysis. The components of dolomite rock samples and hydrated calcium oxalate formed during the alteration processes of the rocks were characterized, and the decomposition mechanisms of these components were determined. The TG–DTA experiments carried out at CO2 atmosphere were used to determine the carbonate compounds in the rock samples. The TG–DTA study characterized the presence of organic compounds formed during the biological degradation of the rock samples, possibly responsible of the hydrated calcium oxalate formation.

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Abstract  

The Na4UO2(O2)3·8H2O complex was prepared from aqueous systems and its crystallographic and chemical structural conformation characterized. IR spectroscopy and X-ray diffraction were used for analyzing the solid crystal extracted with ethanol to determine the anionic compositon. Composition of the solid phase did not depend on the molar ratio of the reactants or on the pH of the medium, but only upon the absolute concentrations of uranium and alkali. It was observed that the temperature significantly influenced the crystal structure of the product and that a limit to the UO2 concentration existed for inducing the production of a mixture of soluble and insoluble species.

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Journal of Thermal Analysis and Calorimetry
Authors:
L. Núñez-Regueira
,
J. Rodríguez-Añón
,
J. Proupín-Castiñeiras
, and
A. Romero-García

Abstract  

Calorific values and flammability changes during a year for forest waste originating from silviculture task in Galicia (NW Spain) are reported. These waste materials are becoming to be used as alternative fuels. The present study was made on several hardwood forest species. These forest species occupy nowadays approximately 30% of the total forest surface of Galicia. Calorific values were measured by static bomb calorimeter in an oxygen atmosphere. Flammability was determined using a standard epiradiator. Simultaneously, some other parameters such as elementary chemical composition, heavy metal contents, moisture, density, ash percentage after combustion in the bomb, and main bioclimatic characteristics, were also determined.

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Abstract  

Electrical conductivity of aqueous solutions of dodecylpyridinium chloride and bromide have been determined. From these data the critical micelle concentration (cmc) was determined. The thermal properties as standard Gibbs free energy, enthalpy and entropy of micellization was estimated from a uncharged-phase separation model and enables to obtain another properties like heat capacity of micellization and the relevant parameters in the minimum of temperature dependence of cmc. The enthalpy-entropy compensation was shown for the studied compounds.

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Restricted access
Journal of Thermal Analysis and Calorimetry
Authors:
E. Stepkowska
,
Z. Sulek
,
J. Perez-Rodriguez
,
A. Justo
, and
C. Maqueda
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Abstract  

The electrophoretic mobility of some radionuclides has been measured to understand its attractive or repulsive tendencies towards other charged species in the medium. In this study, the chemical state of trace concentrations of88Y,103Ru,134Cs, and141Ce in the presence of UO 2 2+ , as a dominant component, in strongly alkaline aqueous solutions (pH>13) was characterized.88Y and141Ce settled almost completely as colloidal species; whereas103Ru,134Cs, and uranium remained as ions. These results closely correlate a procedure for defining both the composition of the water in contact with the fuel and the practical applicability of modified sorbents.

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Abstract  

A study was undertaken to determine experimentally the uptake of pollutants into of the different parts of the water hyacinth (Eichhornia crassipes) found in “José Antonio Alzate” dam in the State of México, México. There is evidence for efficient and significant root accumulation of Ti, Mn, Fe, and Ba; but in the upper parts concentrations was consistently determined by the degree of watering. However, a significant input could by derived from a common generic source, such as the atmospheric deposition. The experimental study would, therefore, indicate that water hyacinth species can be highly effective in providing a control and treatment buffer for toxic discharges to the dam.

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