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Journal of Thermal Analysis and Calorimetry
Authors:
V. Ramírez-Valle
,
M. Jiménez de Haro
,
M. Avilés
,
L. Pérez-Maqueda
,
A. Durán
,
J. Pascual
, and
J. Pérez-Rodríguez

Abstract  

Static and dynamic heating of vermiculite samples from Santa Olalla, Huelva, Spain, saturated with different cations, i.e. Na+, Cs+, NH4 +, Mg2+, Ca2+, Ba2+ and Al3+, have been studied. The characterization of the phases formed during heating has been carried out by X-ray diffraction. The phases formed depend on the cation present in the interlamellar position and the heating process. The phases identified in the vermiculite samples saturated with different cations and heated at different temperatures are the following: enstatite, forsterite, spinel, cordierite, anorthite, pollucite, nepheline, coesite, celsian and others various mixed silicates; also some dehydrated and amorphous phases have been observed. On static heating, at the maximum temperature reached in this work, the phases formed appear mixed with a glassy phase.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
G. Capote Rodriguez
,
R. Padilla Alvarez
,
G. Pérez Zayas
,
A. Hernández Rivero
,
M. López Reyes
,
S. Ribeiro Guevara
, and
J. Molina Insfrán

Abstract  

Thirty elements were determined by INAA in Cuban soil samples collected in 17 zones from western regions of Cuba, which were affected by neuropathy epidemic in 1992. The presence of toxic elements was evaluated to provide data for the analysis of possible paths of intoxication through local agriculture product consumption. The results obtained for As, Th and U are compared with similar data reported on literature.

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Journal of Thermal Analysis and Calorimetry
Authors:
F. Fraga
,
V. Soto
,
J. Blanco-Méndez
,
A. Luzardo-Alvarez
,
E. Rodríguez-Núñez
,
J. Martínez-Ageitos
, and
M. Pérez

Abstract  

Knowledge of the the kinetic study of chitosan/genipin allow to know the different effects that time and temperature have on the cure reaction of the material. The total enthalpy of reaction, the glass transition temperature and the partial enthalpies have been determined using DSC in dynamic mode. Two models, one based on chemical kinetics and the other accounting for diffusion were used. The incorporation of the diffusion factor in the second model allowed for the cure kinetics to be predicted the whole range of conversion.

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Journal of Thermal Analysis and Calorimetry
Authors:
M. I. Loría-Bastarrachea
,
W. Herrera-Kao
,
J. V. Cauich-Rodríguez
,
J. M. Cervantes-Uc
,
H. Vázquez-Torres
, and
A. Ávila-Ortega

Abstract

The aim of this study was to gain some fundamental knowledge on the thermal degradation pathways of poly(N-vinyl pyrrolidone) using Thermogravimetry coupled with Fourier Transform Infrared Spectroscopy (TG–FTIR) in addition to IR and 1H NMR spectroscopic studies of the partially degraded samples. It was found that the vinyl pyrrolidone is the main volatile products of the thermal degradation of PVP which implies that the predominant mechanism during thermal degradation of this polymer is the depolymerization to monomer of the polymeric main chain; however, it is evident that simultaneous reactions may be involved yielding oligomers. FTIR and 1H NMR spectra of partially degraded samples of PVP exhibited very similar characteristics to that observed for undegraded samples although the 1H NMR spectra suggest the presence of simultaneous reactions as the fragmentation of polymeric main chain.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
E. Shumilin
,
St. Kalmykov
,
D. Sapozhnikov
,
E. Nava-Sánchez
,
D. Gorsline
,
L. Godinez-Orta
,
Yu. Sapozhnikov
,
O. Holguin Quiñones
, and
A. Rodriguez Castaneda

Abstract  

The vertical distribution of K, Rb, Cs, Ca, Sr, Ba, Fe, Cr, Co, Ni, Zn, Sc, Zr, Sb, Se and As was studied by means of instrumental neutron activation analysis in four sediment cores collected from the eastern shelf of tectonically active Baja California peninsula accompanied by 210Pb age-dating. 210Pb analysis was performed by extraction chromatography with measuring the ingrowing daughter 210Bi radioactivity by liquid-scintillation spectrometry. It was found that concentration variations of Se, As, Sb, Zr and Zn are probably controlled by the intensity and composition of the material supplied from the drainage basin constituted by volcanic and sedimentary rocks.

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Community Ecology
Authors:
B. Hermosillo-Nuñez
,
F. Rodríguez-Zaragoza
,
M. Ortiz
,
C. Galván-Villa
,
A. Cupul-Magaña
, and
E. Ríos-Jara

The spatial distribution and abundance of the seven most abundant species of echinoderms (Diadema mexicanum, Centrostephanus coronatus, Eucidaris thouarsii, Isostichopus fuscus, Pharia pyramidatus, Phataria unifascialis and Acanthaster ellisii) were evaluated in coral communities of Isla Isabel National Park (Mexico). Biological (corals and other benthic groups) and physical (rocks and boulders) structural elements of the habitat were evaluated to determine their relationship to these species. Our results show that species composition and abundance varied among sampling sites and between seasons. Also were obtained significant differences in the echinoderm assemblage among sites across seasons. Similar results were detected for the environmental variables related to benthic habitat structure. D. mexicanum, P. unifascialis, E. thouarsii and C. coronatus were the main contributors to the species abundance and distribution in Isla Isabel. Most echinoderm species were positively related to the coverage of different coral species, algae and various types of benthic organisms as well as to physical benthic variables. These outcomes suggest that the spatial distribution and abundance of these echinoderms are explained by the habitat structure, which should be used to design conservation and management strategies for coral communities.

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Journal of Psychedelic Studies
Authors:
Abraham Hafiz Rodriguez
,
Sarah Nath Zallek
,
Michael Xu
,
Jean Aldag
,
Lori Russell-Chapin
,
Tobias A. Mattei
, and
N. Scott Litofsky

Abstract

Background

Music has been associated with therapeutic properties for thousands of years across a vast number of diverse regions and cultures. This study expands upon our current understanding of music’s influence on human neurophysiology by investigating the effects of various music genres on cerebral cortex activity using electroencephalography (EEG).

Methods

A randomized, controlled study design was used. EEG data were recorded from 23 healthy adults, ages 19–28, while listening to a music sequence consisting of five randomized songs and two controls. The five studied music genres include: Classical, Tribal Downtempo, Psychedelic Trance (Psytrance), Goa Trance, and Subject Choice.

Results

Controls were associated with lower percentages of beta frequencies and higher percentages of alpha frequencies than the music genres. Psytrance was associated with higher percentages of theta and delta frequencies than the other music genres and controls. The lowest percentages of beta frequencies and highest percentages of alpha frequencies occurred in the occipital and parietal regions. The highest percentages of theta and delta frequencies occurred in the frontal and temporal regions. Subjects with prior music training exhibited increased percentages of delta frequencies in the frontal region. Subject gender and music preference did not have a significant influence on frequency band percentages.

Conclusions

Findings from this study support those of previous music therapy studies and provide novel insights regarding music’s influence on human neurophysiology. These findings also support the hypothesis that music may promote changes in cerebral cortex activity that have similarities to non-rapid eye movement (NREM) sleep, while the listener remains awake.

Open access
Journal of Radioanalytical and Nuclear Chemistry
Authors:
A. Perera
,
C. Perez
,
M. Torres
,
A. Henandez
,
F. Heres
,
T. Moreira
,
A. Gutierrez
,
A. Gigato
,
I. Hernandez
,
L. Alberti
,
O. Marrero
,
L. Martinez
,
J. Sanfiz
,
E. Sanchez
,
J. Rodriguez
,
L. Marrero
, and
G. Parra

Abstract  

The aim of this work was to obtain a freeze-dried kit for direct99mTc-labeling of human polyclonal IgG. The labeling procedure was carried out by Schwarz's method. The best yields of99mTc-IgG were obtained by using sodium pyrophosphate decahydrate as a weak chelating agent. Performed tests showed the stability of the radiopharmaceutical up to 24 hours. Plasma clearance in rats was fitted to a biexponential curve withT 1/2α=(0.1 ±0.9) h andT 1/2β=(10±3) h. The organs with higher uptake of radiopharmaceutical were lung, kidneys and blood. In a rabbit model the abscess target/background ratio was 3–6 according to time of the scintigraphic images. Thirty patients with musculoskeletal infection were studied. Twenty-one lesions were detected and confirmed by culture/biopsy.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
J. D. T. Arruda-Neto
,
A. C. Cestari
,
C. B. Zamboni
,
M. Saiki
,
G. P. Nogueira
,
L. E. C. Fonseca
,
M. V. Manso-Guevara
,
A. Deppman
,
V. P. Likhachev
,
J. Mesa
,
O. A. M. Helene
,
S. A. C. Jorge
,
M. N. Martins
,
A. N. Gouveia
,
O. Rodriguez
,
F. Guzmán
, and
F. Garcia

Summary  

Neutron activation analysis has been used to study uranium incorporation in poultry bones as function of chow doped with: (a) uranium (20 ppm); (b) U-doped food (20 ppm) plus phytase (120 ppm) and (c) U-doped food (20 ppm) plus phytase (180 ppm). To investigate this situation experiments involving several groups of Cobb broilers was performed. Two animals per group were sacrificed weekly up to their adultness and uranium concentration in the tibia was measured. It was observed that the concentration of uranium (µg U/g bone) is decreasing all along the animal life spanning period of 14-42 days. This behavior suggests that the skeleton mass is growing faster than the corresponding accumulation of uranium. The administration of phytase seems not to alter this scenario.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
M. Pham
,
M. Betti
,
P. Povinec
,
M. Benmansour
,
R. Bojanowski
,
P. Bouisset
,
E. Calvo
,
G. Ham
,
E. Holm
,
M. Hult
,
C. Ilchmann
,
M. Kloster
,
G. Kanisch
,
M. Köhler
,
J. La Rosa
,
F. Legarda
,
M. Llauradó
,
A. Nourredine
,
J.-S. Oh
,
M. Pellicciari
,
U. Rieth
,
A. Rodriguez y Baena
,
J. Sanchez-Cabeza
,
H. Satake
,
J. Schikowski
,
M. Takeishi
,
H. Thébault
, and
Z. Varga

Abstract  

A new Reference Material (RM) for radionuclides in mussel (Mytilus galloprovincialis) from the Mediterranean Sea (IAEA-437) is described and the results of the certification process are presented. Four radionuclides (40K, 234U, 238U, and 239+240Pu) have been certified, and information values on massic activities with 95% confidence intervals are given for nine radionuclides (137Cs, 210Pb(210Po), 226Ra, 228Ra, 228Th, 230Th, 232Th, 235U, and 241Am). Results for less frequently reported radionuclides (90Sr, 129I, 238Pu, 239Pu, and 240Pu) are also reported. The RM can be used for quality assurance/quality control of the analysis of radionuclides in mussel samples, for the development and validation of analytical methods and for training purposes. The material is available in 200 g units.

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