Digital deposition of yttria patterns on titanium sheets

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1997.Includes bibliographical references (leaf 77).The ability to apply Yttria patterns on titanium sheets is required on a secondary manufacturing operation. The freedom to create 2 dimensional patterns as well as 3 dimensional ones by using Three Dimensional Printing allows for the application of Yttria patterns onto these sheets without the use of any type of screens. Two methods for creating these patterns were identified and studied. The first approach consists of selectively printing binder on top of spread layer of powder. A second layer of powder is spread while the binder is still wet. The binder will then dry fixing the Yttria powder to the sheet on the selected positions. Sheets were printed using different particle sizes. Results show that patterns can be applied with good edge definition and uniform thickness using powder ranging from -53[mu]m down to -20[mu]m. The sheets were tested successfully in the secondary operation. And alternative approach consists of mixing the binder and the ceramic powder to create a slurry. The slurry will then be selectively printed onto the sheet using Three Dimensional Printing. A formulation for a -20 [mu]m Yttria powder slurry was developed using Poly Acrylic Acid as dispersant and Polyethylene Glycol as binder. Slurries with 20 volume fraction and less were dispersed and jetted through a 102 [mu]m nozzle. These slurries adhered well to the titanium sheet as they were printed. The formulation was tested successfully in the secondary operation. Following the High-Risk Approach patterns without deflection were printed. For a 102 [mu]m nozzle the best flow rate was determined, as well as the optimal line spacing. The best procedure to print a certain area was to print a first round of lines, dry them and then print lines in between the first set. The average roughness of the layer printed was 14 [mu]m. In order to allow future printing of slurries with a nozzle size of 102 [mu]m and deflection, the design of a print head to accommodate these slurries was also investigated.by Gabriel Fernandez.S.M

Experimental behaviour of a three-stage metal hydride hydrogen compressor

A three-stage metal hydride hydrogen compressor (MHHC) system based in AB2-type alloys has been set-up. Every stage can be considered as a Sieverts-type apparatus. The MHHC system can work in the pressure and temperature ranges comprised from vacuum to 250 bar and from RT to 200C, respectively. An efficient thermal management system was set up for the operational ranges of temperature designed. It dumps temperature shifts due to hydrogen expansion during stage coupling and hydrogen absorption/desorption in the alloys. Each reactor consists of a single and thin stainless-steel tube to maximize heat transfer. They are filled with similar amount of AB2 alloy. The MHHC system was able to produce a compression ratio (CR) as high as of 84.7 for inlet and outlet hydrogen pressures of 1.44 and 122 bar for a temperature span of 23 to 120C

Role of alkali-cyano group interaction in g-C3N4 based catalysts for hydrogen photo-production

Carbon nitride based materials incorporating K and Na alkali ions were used as support(s) to deposit platinum. The systems were tested in the photo-production of hydrogen using methanol as a sacrificial molecule. Tests under UV and sunlight-type illumination conditions showed an important promoting effect of the alkali ions irrespective of the illumination source characteristics. The measurement of the quantum efficiency was used to quantitatively assess the performance of the catalysts. Outstanding results were obtained, particularly under sunlight illumination. A complete characterization study of the materials was carried out to establish a structure-activity link. This link correlates catalytic activity with the capture of charge carrier species by surface cyano groups directly associated with the presence of alkali ions at the carbon nitride componen

Morphological study of skin cancer lesions through a 3D scanner based on fringe projection and machine learning

The effective and non-invasive diagnosis of skin cancer is a hot topic, since biopsy is a costly and time-consuming surgical procedure. As skin relief is an important biophysical feature that can be difficult to perceive with the naked eye and by touch, we developed a novel 3D imaging scanner based on fringe projection to obtain morphological parameters of skin lesions related to perimeter, area and volume with micrometric precision We measured 608 samples and significant morphological differences were found between melanomas and nevi (p<0.001). The capacity: of the 3D scanner to distinguish these lesions was supported by a supervised machine learning algorithm resulting in 80.0% sensitivity: and 76.7% specificity. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreemen

Invasive micropapillary carcinoma of the breast overexpresses MUC4 and is associated with poor outcome to adjuvant trastuzumab in HER2-positive breast cancer

Invasive micropapillary carcinoma of the breast (IMPC) is a histological tumor variant that occurs with low frequency characterized by an inside-out formation of tumor clusters with a pseudopapillary arrangement. IMPC is an aggressive tumor with poor clinical outcome. In addition, this histological subtype usually expresses human epidermal growth factor receptor 2 (HER2) which also correlates with a more aggressive tumor. In this work we studied the clinical significance of IMPC in HER2-positive breast cancer patients treated with adjuvant trastuzumab. We also analyzed mucin 4 (MUC4) expression as a novel biomarker to identify IMPC.Fil: Mercogliano, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Inurrigarro, Gloria. Sanatorio Mater Dei Hermanas de María de Schoenstatt; ArgentinaFil: de Martino, Mara. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Venturutti, Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Rivas, Martin Alfredo. Cornell University; Estados UnidosFil: Cordo Russo, Rosalia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Proietti Anastasi, Cecilia Jazmín. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Fernandez, Elmer Andres. Universidad Católica de Córdoba; ArgentinaFil: Frahm, Isabel. Sanatorio Mater Dei Hermanas de María de Schoenstatt; ArgentinaFil: Barchuk, Sabrina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos ; ArgentinaFil: Allemand, Daniel H.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos ; ArgentinaFil: Figurelli, Silvina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos ; ArgentinaFil: Gil Deza, Ernesto. Instituto Oncológico Henry Moore; ArgentinaFil: Ares, Sandra. Instituto Oncológico Henry Moore; ArgentinaFil: Gercovich, Felipe G.. Instituto Oncológico Henry Moore; ArgentinaFil: Cortese, Eduardo. Ministerio de Defensa. Fuerza Aérea Argentina. Hospital Aeronáutico Central ; ArgentinaFil: Amasino, Matías. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Guzmán, Pablo. Universidad de La Frontera; ChileFil: Roa, Juan C.. Universidad de La Frontera; ChileFil: Elizalde, Patricia Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Schillaci, Roxana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Seismic motion in urban sites consisting of blocks in welded contact with a soft layer overlying a hard half space: I. Finite set of blocks

We address the problem of the response to a seismic wave of an urban site consisting of $N$ non-identical, non-equispaced blocks overlying a soft layer underlain by a hard substratum. The results of a theoretical analysis, appealing to a space-frequency mode-matching (MM) technique, are compared to those obtained by a space-time finite element (FE) technique. The two methods are shown to give rise to the same prediction of the seismic response for N=1 and N=2 blocks. The mechanism of the interaction between blocks and the ground, as well as that of the mutual interaction between blocks, are studied. It is shown that the presence of a small number of blocks modifies the seismic disturbance in a manner which evokes qualitatively, but not quantitatively, what was observed during the 1985 Michoacan earthquake in Mexico City. Disturbances at a much greater level, induced by a large number of blocks (in fact, a periodic set) are studied in the companion paper.Comment: submitted to Geophys.J.Int

AGT haplotype in ITGA4 gene is related to antibody-mediated rejection in heart transplant patients

[Abstract] Introduction. One of the main problems involved in heart transplantation (HT) is antibody-mediated rejection (AMR). Many aspects of AMR are still unresolved, including its etiology, diagnosis and treatment. In this project, we hypothesize that variants in genes involved in B-cell biology in HT patients can yield diagnostic and prognostic information about AMR. Methods. Genetic variants in 61 genes related to B-cell biology were analyzed by next generation sequencing in 46 HT patients, 23 with and 23 without AMR. Results. We identified 3 single nucleotide polymorphisms in ITGA4 gene (c.1845G>A, c.2633A>G, and c.2883C>T) that conformed the haplotype AGT-ITGA4. This haplotype is associated with the development of AMR. Moreover, AMR patients with the haplotype AGT-ITGA4 present lower levels of integrin α-4 in serum samples compared to the reference GAC haplotype in control patients. Conclusion. We can conclude that polymorphisms in genes related to the biology of B-cells could have an important role in the development of AMR. In fact, the AGT haplotype in ITGA4 gene could potentially increase the risk of AMR.Instituto de Salud Carlos III; PI13/0217

Effectiveness of rotavirus vaccination in Spain

With the aim of determining rotavirus vaccine effectiveness (RVVE) in Spain, from Oct-2008/Jun-2009, 467 consecutive children below 2 years old with acute gastroenteritis (AGE) were recruited using a pediatric research network (ReGALIP-www.regalip.org) that includes primary, emergency and hospital care settings. Of 467 enrolled children, 32.3% were rotavirus positive and 35.0% had received at least one dose of any rotavirus vaccine. RRVE to prevent any episode of rotavirus AGE was 91.5% (95% CI: 83.7%-95.6%). RVVE to prevent hospitalization by rotavirus AGE was 95.6% (85.6-98.6%). No differences in RVVE were found regarding the vaccine used. Rotavirus vaccines have showed an outstanding effectiveness in Spain

Hydrogen Storage Materials for Mobile and Stationary Applications: Current State of the Art

One of the limitations to the widespread use of hydrogen as an energy carrier is its storage in a safe and compact form. Herein, recent developments in effective high-capacity hydrogen storage materials are reviewed, with a special emphasis on light compounds, including those based on organic porous structures, boron, nitrogen, and aluminum. These elements and their related compounds hold the promise of high, reversible, and practical hydrogen storage capacity for mobile applications, including vehicles and portable power equipment, but also for the large scale and distributed storage of energy for stationary applications. Current understanding of the fundamental principles that govern the interaction of hydrogen with these light compounds is summarized, as well as basic strategies to meet practical targets of hydrogen uptake and release. The limitation of these strategies and current understanding is also discussed and new directions proposed