Investigation of the Corrosion of Steel by Lead-Bismuth Eutectic (LBE) Using Scanning Electron Microscopy and X-Ray Photoelectron Spectroscopy

Lead Bismuth Eutectic (LBE) has been proposed for use in programs for accelerator transmutation of waste. LBE is the leading candidate material as a spallation target and an option for the sub-critical blanket coolant. The corrosion of 316 and 316L stainless steels by LBE has been studied using UNLV\u27s facilities for Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). We have compared exposed and unexposed samples and studied the differences. Some amount of surface contamination is present on the samples and has been removed by ionbeam etching. The unexposed samples reveal typical stainless steel characteristics: a chromium oxide passivation surface layer and metallic iron and nickel. The exposed samples show protective iron and chromium oxide growths on the surface. Oxygen takes many forms on the exposed samples, including oxides of iron and chromium, carbonates, and organic acids from subsequent handling after exposure to LBE. This is a research project in progress, and accomplishments to date include comparing and confirming what is in the literature, as well as laying a strong foundation for further studies in this project

Serenade for small orchestra

Thesis (M.M.)--Boston Universit

O DIREITO AMBIENTAL SOB A PERSPECTIVA DA PROTEÇÃO INTERNACIONAL À PESSOA HUMANA

The present article intends to analyze the international protection of the environment in the light of the corpus juris and the jurisprudence of the International Human Rights Law. To consider the existence of an International Environmental Law destitute of an anthropocentric branch ”“ which is intended, at an extreme degree, to protect the quality of life and the survival of human beings ”“ would mean a denial of the orientation presented by the jurisprudence of international courts, by a wild range of treaties and by the international doctrine, which is, to embrace the environmental protection with a humanity character. O presente trabalho se propõe a analisar a proteção internacional do meio ambiente à luz do corpus juris do Direito Internacional dos Direitos Humanos. Pensar na existência de um Direito Ambiental Internacional desprovido de uma vertente “antropocêntrica” - destinada, em último grau, à proteção da qualidade de vida e da sobrevivência dos seres humanos à equivaleria a negar a orientação apresentada pela jurisprudência de tribunais internacionais, por tratados e pela doutrina, qual seja, a de emprestar à proteção do meio ambiente um caráter de humanidade

Spectroscopic and Microscopic Investigation of the Corrosion of 316/316L Stainless Steel by Lead-Bismuth Eutectic (LBE) at Elevated Temperatures: Importance of Surface Preparation

The corrosion of steel by lead–bismuth eutectic (LBE) is an important issue in proposed nuclear transmutation schemes. Russian scientists at the IPPE exposed steel samples to oxygen-controlled LBE at temperatures up to 823 K and exposure times up to 3000 h. We have characterized these post-exposure steel samples and unexposed controls, using scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX) and X-ray photoelectron spectroscopy (XPS). Previous researchers have investigated the corrosion by LBE of steel of varying composition. In the present work, we compared two samples having the same composition (standard nuclear grade 316/316L) but different surface preparation: a cold-rolled sample was compared with an annealed sample. The cold-rolled sample had an order of magnitude less corrosion (i.e., both lower oxidation and less weight change) than the annealed sample. Sputter depth profiling of the exposed annealed sample and cold-rolled sample showed a marked difference in oxide layer composition between the annealed and cold-rolled samples. The annealed sample showed a complex oxide structure (iron oxide over chromium/iron oxide mixtures) of tens of microns thickness, while the cold-rolled sample was covered with a rather simple, primarily chromium oxide layer of ∼1 μm thickness

A Comprehensive Economic Stimulus for our Failing Economy

This paper presents a comprehensive plan to fix the ailing American economy, through a five-step approach. First, the Federal Reserve must continue to broaden the scope of monetary policy, by purchasing and selling long-term securities. Manipulating expectations through FOMC statements is another tool at the Federal Reserve’s disposal. Secondly, the government must enact fiscal stimulus to stabilize the economy in the short and medium runs, through investment in infrastructure projects, green technology, fusion technology, and science education. Additionally, the new fiscal policy must tackle the mortgage meltdown, which is weighing down the entire economy. Third, the regulatory system must be changed to reduce the likelihood of another financial collapse, starting with the nationalization of the ratings agencies. Ratings should be updated faster, with a numeric grading system rather than the pre-existing letter grades. Fourth, our globalized economy insures that a coordinated globalized response is necessary to recover. Global cooperation to reduce inflation and avoid protectionist policies is vital. Finally, the American bailout policy must be made clear, only giving bailouts to companies that are sound but financially strapped and those that are too big to fail

Genetic factors influencing murine hematopoietic productivity in culture

In order to study a previously described genetic difference manifested in stem cell kinetics of specific mouse strains, effects of this putative gene, stk , were measured on growth and expansion of stem and progenitor cell populations ex vivo. Bone marrow cells from each of two inbred mouse strains, C57BL/6J and DBA/2J, were placed into separate bioreactor cultures perfused continuously with growth medium containing erythropoietin (Epo), interleukin-3 (IL-3), granulocyte-macrphage colony stimulating factor (GM-CSF), and Kit ligand as well as 5% CO 2 . Expansion of cell numbers reached 20-fold for DBA/2J and 10-fold for C57BL/6J marrow within about 1 week of culture. Significant production was also seen of colonyforming unit (CFU)-GM (up nine-fold from input levels) just prior to the cell production peak, and, importantly, moderate expansion of day 12 colony-forming unit-spleen (CFU-S; two- to threefold) occurred as well, although CFU-S production peaked at a relatively short 4 days. CFU-S and CFU-GM levels declined rapidly in culture, either because of unfavorable growth conditions or terminal differentiation. Attempts to remove toxic metabolites by increasing the media perfusion rate resulted in a boost in cell expansion capability by DBA/2J marrow. In bioreactors in which stromal cells were established before marrow inoculation, there was greater expansion of CFU-S (especially by DBA/2J) and CFU-GM, although total cell yield appeared to be unaffected, perhaps because the maximum cell density had already been reached. The relative high potential for CFU-S expansion measured in DBA/2J marrow over that of C57BL/6J will be useful in following genetic contributions to bone marrow production capacity. © 1995 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49891/1/1041640113_ftp.pd

Safety of ultrasound-guided distal radial artery access for abdominopelvic transarterial interventions: a prospective study

PURPOSEWe aimed to evaluate ultrasound-guided distal radial artery (DRA) access to perform abdominopelvic endovascular procedures.METHODSA prospective, observational study was carried out in a single center between December 2017 and February 2019. Forty-two abdominopelvic endovascular procedures were performed by the same operator in 37 patients with DRA access using a 5 F sheath. Most patients were male (67.6%) with a mean age of 62.0±11.4 years (age range, 27.6–82.8 years). Patient characteristics, including Barbeau’s test classification, radial and ulnar sizes and technical success, were evaluated. Patients with a DRA smaller than 1.7 mm could not be safely punctured and were not included.RESULTSProcedures included chemoembolization of hepatocellular carcinoma in 35 cases (83.3%), embolization of hepatic metastasis in neuroendocrine tumors in 4 cases (9.5%) and other embolization procedures in 3 cases (7.1%). The mean diameters of the DRA, proximal radial artery and proximal ulnar artery were 2.31, 2.63, and 2.09 mm, respectively. Out of 42 DRA puncture attempts, 97.6% (41/42) were successfully performed. There were no postoperative complications related to the access site, such as pain, palsy, paresthesia, occlusion, finger ischemia, bleeding, hematoma, and pseudoaneurysm. Transient forearm discomfort was reported in 7.1% of patients (3/42); one occurrence was associated with kinking rectification, and two occurrences were attributed to small arteries and/or vasospasm.CONCLUSIONUltrasound-guided DRA access seems to be feasible and safe to perform in abdominopelvic endovascular procedures in patients with a DRA considered amenable to be safely punctured, with high technical success rates

Surface studies of Corrosion of Stainless Steel by Lead Bismuth Eutectic

Why is Lead Bismuth Eutectic Important? • Changing national security stances have led to reexamination of nuclear waste reprocessing • Dangerous actinides can be separated and • Transmuted into safer products, creating a waste form dangerous for only hundreds of years, in addition to the production (up to 1/3 of the original fission energy) of useful energy • Non-moderating coolants or spallation targets for production of fast neutrons is required for transmutation • Russian experience with LBE coolants in their nuclear submarine fleet makes LBE an attractive possible transmutation coolant technology • Corrosion of steel by LBE is an important sticking point in the utilization of LB

The Erythropoietin Receptor Stimulates Rapid Cycling and Formation of Larger Red Cells During Mouse and Human Erythropoiesis [preprint]

Erythroid terminal differentiation entails cell divisions that are coupled to progressive decreases in cell size. EpoR signaling is essential for the survival of erythroid precursors, but it is unclear whether it has other functions in these cells. Here we endowed mouse precursors that lack the EpoR with survival signaling, finding that this was sufficient to support their differentiation into enucleated red cells, but that the process was abnormal. Precursors underwent fewer and slower cell cycles and yet differentiated into smaller red cells. Surprisingly, EpoR further accelerated cycling of early erythroblasts, the fastest cycling cells in the bone marrow, while simultaneously increasing their cell size. EpoR-mediated formation of larger red cells was independent of the established pathway regulating red cell size by iron through Heme-regulated eIF2α kinase (HRI). We confirmed the effect of Epo on red cell size in human volunteers, whose mean corpuscular volume (MCV) increased following Epo administration. This increase persisted after Epo declined and was not the result of increased reticulocytes. Our work reveals a unique effect of EpoR signaling on the interaction between the cell cycle and cell growth. Further, it suggests new diagnostic interpretations for increased red cell volume, as reflecting high Epo and erythropoietic stress