4 research outputs found
Synthesis of Nanocomposites from Pd0 and a Hyper-Cross-Linked Functional Resin Obtained from a Conventional Gel-Type Precursor
No full textHyper-cross-linked resins
stemming from a gel-type poly-chloro-
methylated poly(styrene-
co
-divinylben-
zene) resin (GT) have been investigat-
ed by a multi-methodological approach
based on elemental analysis, scanning
electron microscopy, X-ray microanaly-
sis, and solvent absorption. The hyper-
cross-linking of the parent resin was ac-
complished by Friedel–Crafts alkyla-
tion of the phenyl rings of the resins
with the chloromethyl groups. This pro-
duced a permanent pore system com-
prising both micropores (
<
2.0 nm in
diameter) and mesopores (2.2 nm). The
chloromethyl groups that did not react
in the hyper-cross-linking step were
transformed into methylmercaptan
groups and the latter were then con-
verted into sulfonic groups by oxida-
tion with hydrogen peroxide. By this
procedure the extensive permanent po-
rosity of the parent unsulfonated
hyper-cross-linked polymer (HGT) was
retained by the sulfonated polymer
(HGTS). The final exchange capacity
of HGTS was determined to be
0.36 mmolg
1
. HGTS was easily meta-
lated with Pd
II
and the subsequent re-
duction of the metal centers with either
aqueous sodium borohydride, formal-
dehyde, or dihydrogen produced three
Pd
0
/HGTS nanocomposites. The metal
nanoparticles had diameters in the 1–
6 nm range for all the nanocomposites,
as determined by TEM, but with some-
what different distributions. When
formaldehyde was used, more than
90% of the nanoparticles were less
than 3 nm and their radial distribution
throughout the polymer beads was
quite homogeneous. These findings
show that with this reducing agent the
metal nanoparticles are generated
within the pore system of the polymer
matrix, hence their size is controlled by
the dimensions of the pores of the pol-
ymeric suppor
Comparison of the diagenetic and reservoir quality evolution between the anticline crest and flank of an Upper Jurassic carbonate gas reservoir, Abu Dhabi, United Arab Emirates
No full textThis petrographic, stable isotopic and fluid inclusion microthermometric study of the Upper Jurassic limestones of an onshore field, Abu Dhabi, United Arab Emirates (UAE) compares diagenesis in flanks and crest of the anticline. The results revealed that the diagenetic and related reservoir quality evolution occurred during three phases, including: (i) eogenesis to mesogenesis 1, during which reservoir quality across the field was either deteriorated or preserved by calcite cementation presumably derived from marine or evolved marine pore waters. Improvement of reservoir quality was due to the formation of micropores by micritization of allochems and creation of moldic/intragranular pores by dissolution of peloids and skeletal fragments. (ii) Obduction of Oman ophiolites and formation of the anticline of the studied field was accompanied by cementation by saddle dolomite and blocky calcite. High homogenization temperatures (125–175 °C) and high salinity (19–26 wt% NaCl eq) of the fluid inclusions, negative δ18OVPDB values (−7.7 to −2.9‰), saddle shape of dolomite, and the presence of exotic cements (i.e. fluorite and sphalerite) suggest that these carbonates were formed by flux of hot basinal brines, probably related to this tectonic compression event. (iii) Mesogenesis 2 during subsidence subsequent to the obduction event, which resulted in extensive stylolitization and cementation by calcite. This calcite cement occluded most of the remaining moldic and inter−/intragranular pores of the flank limestones (water zone) whereas porosity was preserved in the crest. This study contributes to: (1) our understanding of differences in the impact of diagenesis on reservoir quality evolution in flanks and crests of anticlines, i.e. impact of hydrocarbon emplacement on diagenesis, and (2) relating various diagenetic processes to burial history and tectonic events of foreland basins in the Arabian Gulf area and elsewhere
Behavioral Disorders: A Nutritional Checklist for the Educational Practitioner
No full textMillions of dollars are spent annually on special educational programs for children whose severe behavior disorders prevent them from participating in the regular school setting despite average or above average intellectual capacity. A growing body of research indicates that some of these behavior disorders are related to nutritional problems. (Pfeiffer and Iliev 1972; Kittler 1973; Mayron 1979; and Buckley 1977), and many clinicians support the view that no matter what the etiology of behavioral disorders, nutritional programs can improve the baseline data on medical, social and intellectual achievement, and on personality measures (Palmer 1978). Our purpose here is to present a checklist of physical symptoms associated with dietary problems related to nonadaptive behavior in order to help teachers determine if a medical-nutritional referral is appropriate
Prevalence of gastrointestinal parasites and associated risk factors in cattle from the borja farm, Tierra Grata Manaure–Cesar
No full textDigitalEl objetivo del estudio fue determinar la prevalencia de parásitos gastrointestinales e identificar los factores de riesgos asociados en bovinos del predio Borja, ubicado en la vereda Tierra Grata Manaure – Cesar. Se colectaron 50 muestras fecales en los bovinos seleccionados al azar de una población de 63 animales, los cuales fueron estratificados en 3 grupos etarios: de 0 a 12, de 12 a 24 y >24 meses. Las muestras fueron procesadas en el laboratorio mediante examen coprológico técnica directa para identificación de parásitos. Se identificaron 8 parásitos gastrointestinales que afectan al predio, correspondiendo a una prevalencia del 62% para Entamoeba spp. Eimeria spp. con el 60% y Bunostomum spp. con el 42%, seguido de Giardia spp. con un 14%, Balantidium spp. y Trichostrongylus spp. con un 10% y en menor prevalencia Trichuris spp. con el 8% y Moniezia spp. con el 4%. Se tuvo en consideración la evaluaron factores de riesgo para infecciones gastrointestinales basándose en criterios de bienestar animal establecidos por el ICA, sin embargo, no se encontró relación entre la evaluación de dichos factores y la presencia de los parásitos en el predio, pero sí se identificó como factor de riesgo la edad de los animales, mostrando una mayor presentación de Entamoeba spp. en bovinos adultos que, en terneros, a diferencia que en terneros tuvieron una mayor frecuencia en Eimeria spp.The objective of the study was to determine the prevalence of gastrointestinal parasites and identify associated risk factors in cattle at the Borja property, located in the Tierra Grata Manaure - Cesar area. 50 fecal samples were collected from cattle randomly selected from a population of 63 animals, which were stratified into 3 age groups 0-12, 12-24 and >24 months. The samples were processed in the laboratory by coprological examination to identify parasites.
They identified 8 gastrointestinal parasites that affect the property were identified, corresponding to a prevalence of 62% for Entamoeba spp. Eimeria spp. with 60% and Bunostomum spp. with 42%, followed by Giardia spp. with 14%, Balantidium spp. and Trichostrongylus spp. with 10% and to a lesser extent Trichuris spp. with 8% and Moniezia spp. with 4%. Risk factors for gastrointestinal infections were taken into consideration based on animal welfare criteria established by the ICA, however, no relationship was found between the evaluation of said factors and the presence of parasites on the property, but the age of the animals was identified as a risk factor, showing that calves were more susceptible to certain parasites and vice versa.Introducción 18
Planteamiento del Problema. 20
Objetivos 22
Marco Referencial 23
Antecedentes…………………………………………………………………………………..…24
Protozoarios 27
Eimeria spp.....................................................................................................................................28
Entamoeba spp. 30
Balantidium spp. 31
Giardia spp. 33
Helmintos 35
Bunostomum spp. 35
Trichostrongylus spp. 36
Trichuris spp. 39
Moniezia spp. 40
Diagnóstico de Parásitos Gastrointestinales 43
Técnica Mc.Master 43
Técnica de Baermann 43
Examen Directo 44
Factores de Riesgo para la Presentación de Parásitos Gastrointestinales 44
Bases legales 45
Materiales y Métodos 46
Área de Estudio 46
Trabajo en Campo: Diseño de muestreo 46
Recolección de Muestras e Identificación de Estructuras Parasitarias: 48
Identificación de Factores de Riesgos Asociados a la Presentación de Parásitos Gastrointestinal 48
Análisis y Procesamiento de Datos 49
Aspectos Éticos 49
Resultados 50
Discusión 60
Limitaciones 66
Conclusiones 67
Recomendaciones 68
Referencias Bibliográficas 70
Apéndice 90PregradoMédico Veterinario y Zootecnist
