Search results for "ACID"
showing 10 items of 13107 documents
Effective Recovery Process of Copper from Waste Printed Circuit Boards Utilizing Recycling of Leachate
2020
AbstractThis study presents an optimized leaching and electrowinning process for the recovery of copper from waste printed circuit boards including studies of chemical consumption and recirculation of leachate. Optimization of leaching was performed using response surface methodology in diluted sulfuric acid and hydrogen peroxide media. Optimum leaching conditions for copper were found by using 3.6 mol L−1 sulfuric acid, 6 vol.% hydrogen peroxide, pulp density of 75 g L−1 with 186 min leaching time at 20°C resulting in complete leaching of copper followed by over 92% recovery and purity of 99.9% in the electrowinning. Study of chemical consumption showed total decomposition of hydrogen pero…
Effects of insulin deficiency on exercise-induced acute responses in the regulation of fatty acid oxidation in mouse gastrocnemius muscles
2014
Insulin is a hormone that plays an important role in the regulation of the metabolism of all the main nutrients. Its main function is to stimulate glucose uptake and disposal or utilization by the cells and thus to decrease blood glucose concentration. However, it also inhibits breakdown of proteins and lipids and promotes their synthesis. Type 1 diabetes is a disease in which insulin secretion is impaired because of destruction of pancreatic β-cells. It is characterized by hyperglycemia and increased reliance on fat oxidation. This is seen also as altered gene expression patterns. The purpose of this study was to look into the effects of insulin deficiency on exercise-induced acute respons…
Diastereomeric control of enantioselectivity: evidence for metal cluster catalysis
2014
Enantioselective hydrogenation of tiglic acid effected by diastereomers of the general formula [(μ-H)2Ru3(μ3-S)(CO)7(μ-P–P*)] (P–P* = chiral Walphos diphosphine ligand) strongly supports catalysis by intact Ru3 clusters. A catalytic mechanism involving Ru3 clusters has been established by DFT calculations. peerReviewed
Revista iberoamericana de educación
2013
El presente trabajo presenta una propuesta validada para elaborar un plan de acción tutorial para estudiantes universitarios con discapacidad. Por una parte, analiza las actuaciones tutoriales realizadas por los servicios de atención al estudiante con discapacidad de cuarenta universidades españolas, considerando sobre todo los momentos clave en la trayectoria del estudiante, que se vinculan con la promoción, la acogida, la permanencia y el egreso. Del análisis efectuado destaca llamativamente el que no existan planes de acción tutoriales, ni globales ni específicos, dirigidos al colectivo de estudiantes con discapacidad. Por otra parte, se presenta una propuesta validada de plan de acción …
The Effects of Green Tea (Camellia sinensis), Bamboo Extract (Bambusa vulgaris) and Lactic Acid on Sebum Production in Young Women with Acne Vulgaris…
2022
People struggling with acne vulgaris, not only experience skin eruptions and skin pain, but also report that their quality of life is worse compared with healthy people. This study examined, for the first time, the effect of sonophoresis on select skin parameters (sebum level) in young women suffering from acne vulgaris. The study included 60 women 19–23 years of age (M = 21.45, SD = 0.91) with mild and moderate facial acne. The inclusion criteria were 19–23 years of age, female or male gender, mild to moderate acne, no dermatological treatment within last 12 months, and no hormonal contraception (women). No men volunteered for the study, so the group was homogeneous. The patients were divi…
Determination of the atmospheric precipitation pH value on the basis of the analysis of lichen cationoactive layer constitution
2006
Studies of equilibria and kinetics of the ion exchange process between the surrounding (water solution) and lichens prove that the number of mobile hydrogen ions bonded in lichens depends on the concentration of hydrogen ions in the precipitation with which the lichens are in contact and the type and concentration of other cations contained in the precipitation. The measurement of these values was suggested; as a result, it enabled to determine the pH of precipitation by determination of mobile cations bonded in exposed or naturally grown lichens. The studies were conducted on Hypogymnia physodes lichens.
PET Imaging of the Impact of Extracellular pH and MAP Kinases on the p-Glycoprotein (Pgp) Activity
2012
The functional activity of p-glycoprotein (Pgp) can be increased in vitro by an extracellular acidosis via activation of MAP kinases (p38, ERK1/2). In order to study these effects in vivo a new (68)Ga-labeled PET tracer was developed which serves as a substrate of the Pgp and therefore indirectly mirrors the Pgp activity. For in vivo studies, experimental tumors were imaged under acidic conditions (inspiratory hypoxia, injection of lactic acid) and during inhibition of MAP kinases in a μ-PET system. In vitro, [(68)Ga]MFL6.MZ showed an accumulation within the cells of about 20% which was increased to 30% by Pgp inhibition. In solid tumors a marked tracer uptake was observed showing spatial h…
Self-assembly mechanism based on charge density topological interaction energies
2017
The packing interactions have been evaluated in the context of the self-assembly mechanism of crystal growth and also for its impacts on the aromaticity of the trimesate anion. The structure of ethylammonium trimesate hydrate (1) measured at 100 K and a charge density model, derived in part from theoretical structures, is reported. Theoretical structure factors were obtained from the geometry-optimized periodic wave function. The trimesic acid portion of 1 is fully deprotonated and participates in a variety hydrogen bonding motifs. Topological analysis of the charge density model reveals the most significant packing interactions and is then compared to a complementary analysis performed by …
Análisis del efecto del aprendizaje organizativo en el nivel de internacionalización de las empresas, y del papel mediador de la capacidad para compe…
2015
En la incierta arena del comercio internacional convergen organizaciones de tamaños diferentes, que están inmersas en un ámbito en el que predomina la hipercompetencia. El fenómeno de la hipercompetencia es el resultado de la dinámica de las maniobras estratégicas de las empresas con el objetivo de alcanzar una fuerte posición basada en la creación de una propuesta valiosa para los clientes, la cual facilita “moverse primero”, bien sea para defender o para atacar una posición en un mercado geográfico con un producto dado (D’Aveni, 1995; D’Aveni, Canger y Doyle, 1995; D’Aveni, Dagnino y Smith, 2010). La “hipercompetencia”, es descrita por D’Aveni (1995:46), una situación en la cual “la frecu…
Mujeres racializadas y protección social: un análisis de la acción interseccional del género, la etnia-raza y la clase en el proceso decisional que d…
2023
Mujeres racializadas y protección social: Un análisis de la acción interseccional del género, la etnia-raza y la clase en el proceso decisional que da forma a la política de protección social ejecutada a través de los programas de transferencias monetarias en el Perú (2001-2020) Esta tesis tuvo como objetivo general analizar la forma en que actúan e interactúan el género, la clase y la etnia-raza en el proceso de configuración de la política de protección social en el Perú, ejecutada a través de los programas de transferencias monetarias. Investigar estos programas ha sido relevante, dado que se han constituido en modelos de referencia para el diseño de políticas y sistemas de protección so…