Vibrational spectroscopy of phosphate-based electrodes for lithium rechargeable batteries.

The favorable energy densities and cycling performances attainable from lithium rechargeable batteries has prompted aggressive research in this field for over 30 years. In particular, phosphate-based electrodes receive much attention due to their competitive redox potentials, capacities, and enhanced safety compared to currently commercialized systems. In developing these materials, it is critical to have a good understanding of the fundamental reactions that occur during cycling. Vibrational spectroscopy is particularly useful in this regard because it is sensitive to the local structure of the electrodes. However, few researchers use vibrational spectroscopy to study lithium intercalation in phosphate-based electrodes. The intramolecular vibrations of the phosphate anions yield intense bands in the Raman and infrared spectrum that are sensitive to the immediate local environment of the phosphate anions; thus they are natural candidates for the technique. Measuring the infrared or Raman spectrum of these materials at various states of charge can provide a wealth of information about local structural changes and charge compensation reactions occurring within an electrode from the perspective of the phosphate anions.The first objective of this dissertation is to examine lithium intercalation with vibrational spectroscopy for three families of phosphate-based electrodes: phospho-olivine LiMPO4 (M = Fe, Mn) cathodes, LISICON Li3 M2(PO4)3 (M = V, Ti) cathodes, and LiSn2(PO4)3 and Sn3(PO4) 2 anodes. Symmetry-based analyses are used to interpret the vibrational modes of each compound. Vibrational spectra recorded at various states of charge demonstrate the sensitivity of the phosphate anions to the presence of lithium ions and provide insight into the lithium intercalation reactions that occur within these materials. The second objective of this dissertation is to describe new in situ electrochemical cells for Raman and infrared spectroscopy. For example, a relatively cheap in situ Raman cell based on modified coin cells is tested with V2O 5 cathodes. The field of in situ infrared spectroscopy is extended to include transmission experiments. The performance of a new in situ transmission FT-IR spectroelectrochemical cell is tested with FePO4 cathodes, and the results agree very well with ex situ experiments. Both techniques provide new ways to study lithium intercalation for a range of advanced electrode materials

Geological-morphological description of the Sedna and Guinevre planitiae on Venus (photomap sheets B-11, B-20, B-21)

Presented are descriptions and maps of the region of Sedna and Guinevra Planitiae--representatives of the largest geological providense on Venus comprised of volcanic rock. Units of different age are isolated and their relations are given, as well as interpretations of proposed mechanisms of formation

Relief and geology of the north polar region of the planet Venus

Description of topographic features is given for the North polar region of the planet Venus. Principal geomorphic types of terrain are characterized as well as their geologic relations. Relative ages of geologic units in Venus North polar region are discussed

Exploration Medical System Technical Architecture Overview

The Exploration Medical Capability (ExMC) Element Systems Engineering (SE) goals include defining the technical system needed to support medical capabilities for a Mars exploration mission. A draft medical system architecture was developed based on stakeholder needs, system goals, and system behaviors, as captured in an ExMC concept of operations document and a system model. This talk will discuss a high-level view of the medical system, as part of a larger crew health and performance system, both of which will support crew during Deep Space Transport missions. Other mission components, such as the flight system, ground system, caregiver, and patient, will be discussed as aspects of the context because the medical system will have important interactions with each. Additionally, important interactions with other aspects of the crew health and performance system are anticipated, such as health & wellness, mission task performance support, and environmental protection. This talk will highlight areas in which we are working with other disciplines to understand these interactions

Manejo de semilla básica de ajo en condiciones controladas

Con el avance de la tecnología de producción de semilla de ajo en la Argentina, ya nadie duda sobre la importancia de la calidad de la misma, principal componente de los rendimientos comerciales del cultivo. El atributo calidad en semilla de ajo implica dos conceptos: calidad genética, es decir alta pureza varietal, y calidad sanitaria, es decir libre de patógenos sistémicos que se trasmiten por semilla. La semilla de alta pureza varietal (cultivares inscriptos por criaderos en el Registro Nacional del Instituto Nacional de Semillas – INASE y producidos por semilleros inscriptos), garantizan fundamentalmente un gran potencial de rendimiento comercial y gran uniformidad, no solo en las características agronómicas (período de dormición, simultaneidad de emisión de vara floral, homogeneidad de punto de cosecha, etc.), sino características comerciales (grandes calibres, formatos uniformes, compacidad, etc.). La semilla de alta sanidad (producida por laboratorios y viveros prestigiosos), garantizan estar libres tanto de patógenos como el causante de la “podredumbre blanca” (Sclerotium cepivorum y Sclerotium rolfsii), o de la “tristeza” (fitoplasma), como de nematodos (Ditylenchus dipsaci), o saneados de virosis de alta peligrosidad (OYDV, LYSV entre otros). Esta semilla se obtiene en diferentes etapas, en la que, durante varios años, participan criaderos, laboratorios, viveros y multiplicadores. La Ley Nacional Nº 20.247 (Semillas y Creaciones Fitogenéticas) y las Resoluciones 242, 243, 244, 255/98 del Instituto Nacional de Semillas (INASE), regulan la producción de semilla de ajo en la Argentina, estableciendo Categorías y Clases. En este texto solo se hará referencia a la producción de semilla básica de las sub categorías desde Pre Inicial (M0) hasta Fundación (M3), ya que son estas las que presenta mayores desafíos y desarrollos tecnológicos en mano de los multiplicadores luego que la semilla Pre Inicial sale de los laboratorios. La semilla básica puede salir del laboratorio en forma de micro plantas o microbulbillos (obtenidos in vitro), o minibulbillos rusticados, los que deben continuar las sucesivas etapas de multiplicación en jaulas con mallas a pruebas de pulgones (jaulas antiáfidos), teniendo en cuenta que son estos insectos los vectores de los principales virus.EEA La ConsultaFil: Burba, Jose Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; ArgentinaFil: Ocañas, Ramon Orlando. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; ArgentinaFil: Lanzavechia, Gabriel Emilio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; ArgentinaFil: Paganini, M. Pasante. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentin

Development of a laboratory system and 2D routing analysis to determine solute mixing within aquatic vegetation

A laser induced fluorometry (LIF) system was developed to quantify mixing within spatially variable aquatic vegetation. A comparison is made between intrusive fluorometry techniques and the application of LIF, to quantify mixing in real vegetation in the laboratory setting. LIF provides greater spatial resolution when compared to point fluorometry. Furthermore, LIF is non-intrusive. A two-dimensional routing procedure is used to calculate the longitudinal and transverse velocities and mixing coefficients from a single pulse injection of tracer within a vegetation patch

Histone Deacetylase Inhibition Enhances Self Renewal and Cardioprotection by Human Cord Blood-Derived CD34+ Cells

Abstract BACKGROUND: Use of peripheral blood- or bone marrow-derived progenitors for ischemic heart repair is a feasible option to induce neo-vascularization in ischemic tissues. These cells, named Endothelial Progenitors Cells (EPCs), have been extensively characterized phenotypically and functionally. The clinical efficacy of cardiac repair by EPCs cells remains, however, limited, due to cell autonomous defects as a consequence of risk factors. The devise of "enhancement" strategies has been therefore sought to improve repair ability of these cells and increase the clinical benefit. PRINCIPAL FINDINGS: Pharmacologic inhibition of histone deacetylases (HDACs) is known to enhance hematopoietic stem cells engraftment by improvement of self renewal and inhibition of differentiation in the presence of mitogenic stimuli in vitro. In the present study cord blood-derived CD34(+) were pre-conditioned with the HDAC inhibitor Valproic Acid. This treatment affected stem cell growth and gene expression, and improved ischemic myocardium protection in an immunodeficient mouse model of myocardial infarction. CONCLUSIONS: Our results show that HDAC blockade leads to phenotype changes in CD34(+) cells with enhanced self renewal and cardioprotection