Improved shaping approach to the preliminary design of low-thrust trajectories

This paper presents a general framework for the development of shape-based approaches to low-thrust trajectory design. A novel shaping method, based on a three-dimensional description of the trajectory in spherical coordinates, is developed within this general framework. Both the exponential sinusoid and the inverse polynomial shaping are demonstrated to be particular two-dimensional cases of the spherical one. The pseudoequinoctial shaping is revisited within the new framework, and the nonosculating nature of the pseudoequinoctial elements is analyzed. A two step approach is introduced to solve the time of flight constraint, related to the design of low-thrust arcs with boundary constraints for both spherical and pseudoequinoctial shaping. The solution derived from the shaping approach is improved with a feedback linear-quadratic controller and compared against a direct collocation method based on finite elements in time. The new shaping approach and the combination of shaping and linear-quadratic controller are tested on three case studies: a mission to Mars, a mission to asteroid 1989ML, a mission to comet Tempel-1, and a mission to Neptune

Diet shapes the ability of human intestinal microbiota to degrade phytate - in vitro studies

Aims: Investigation of intestinal bacterial groups involved in phytate degradation and the impact of diets with different phytate contents on phytase activity. Methods and Results: Faecal samples of adults on conventional (n = 8) or vegetarian (n = 8) diets and breastfed infants (n = 6) were used as an inoculum for modified media supplemented with phytate. Populations of Gram-positive anaerobes (GPA), lactic acid bacteria (LAB), Proteobacteria-Bacteroides (P-B), coliforms and anaerobes were studied. The PCR-DGGE analysis revealed a random distribution of DGGE profiles in the dendrograms of GPA, P-B and coliforms, and a partially diet-specific distribution in the DGGE dendrograms of LAB and anaerobes. The degradation of phytic acid (PA) was determined with HPLC method in supernatants of the cultures. Regardless of the diet, the Gram-positive anaerobes and LAB displayed the lowest ability to degrade phytate, whereas the coliforms and P-B cultures produced higher amounts of intermediate myo-inositol phosphates. Bacterial populations grown in a nonselective medium were the most effective ones in phytate degradation. It was the vegetarians' microbiota that particularly degraded up to 100% phytate to myo-inositol phosphate products lower than InsP3. Conclusions: A diet rich in phytate increases the potential of intestinal microbiota to degrade phytate. The co-operation of aerobic and anaerobic bacteria is essential for the complete phytate degradation. Significance and Impact of the Study: This study provides insights on the effect of diet on specific metabolic activity of human intestinal microbiota.The work was financed from the funds of the Polish Ministry of Sciences and Higher Education, grant number N N312 434337.Peer Reviewe

Oat–buckwheat breads – technological quality, staling and sensory properties

peer reviewedThe technological and sensory properties and the staling of breads made from oat flour (OF) and buckwheat flour (BF) were analysed. Significant differences in protein and ash content were found in the experimental breads due to significant differences in the composition of the BF and OF used. As the proportion of BF in the recipe increased, a deterioration in the technological properties of the dough and bread as well as an increase in the crumb hardness were observed. The presence of OF in the recipe increased the bread volume, significantly enhanced the lightness of the crust and crumb and improved the overall sensory quality. The OF used in the recipe decreased the starch retrogradation enthalpy value, which is strongly related to a delay in bread staling. The proposed bakery products can be attractive to consumers who are looking for new food products

De tales harinas, tales panes. Granos, harinas y productos de panificación en Iberoamérica

480 págs.-- 1a ed.-- Córdoba: Hugo Báez Editor, 2007.-- CDD 664.752 3.Índice: Prefacio.- Prólogo.- Autores.- Capítulo 1: Trigo / Manuel Gómez Pallarés, Alberto Edel León, Cristina M. Rosell.- Capítulo 2: Maíz / Carla Moita Brites, Mónica Haros, Maria João Trigo, Ruth Pedroza Islas.- Capítulo 3: Arroz / Cristina M. Rosell, Carla Moita Brites, Elevina Pérez, Marcia Gularte.- Capítulo 4: Centeno y Triticale / Carla Moita Brites, Gilberto Igrejas, Alberto Edel León.- Capítulo 5: Cereales menores: Avena, sorgo, mijo / Concha Collar.- Capítulo 6: Cultivos Andinos / Ritva Repo-Carrasco-V, Gladys Cortez, Rafael Onofre Montes, Lidia Quispe Villalpando, Isabel Ramos.- Capítulo 7: Cereales antiguos / Concha Collar.- Capítulo 8: Soja / María Cecilia Puppo, Marcia Arocha Gularte, Gabriela Pérez, Pablo Ribotta, María Cristina Añón.- Capítulo 9: Raíces y tubérculos / Elevina Pérez.- Capítulo 10: Legumbres / Bonastre Oliete, Manuel Gómez Pallarés.- Capítulo 11: Frutos secos / Manuel Gómez Pallarés, Bonastre Oliete, Patricia Ronayne.Los cereales han jugado un papel muy importante en la historia de la civilización, y son la base de la nutrición en gran parte del mundo. Es por ello que han sido objeto de numerosas investigaciones y publicaciones —en especial el trigo, el arroz y el maíz. Sin embargo, pese a la gran producción de cereales en Latinoamérica, la literatura específica sobre su cultivo, procesamiento y productos derivados, en dicho continente, es escasa. Esta desinformación es todavía más acentuada en el caso de los granos andinos y las harinas obtenidas de tubérculos y legumbres. El objetivo de este libro es cubrir dicho vacío y servir de información actualizada sobre el cultivo y uso de los diversos cereales, granos y harinas de otros orígenes que se utilizan en la elaboración de productos de panificación. Para ello se ha recopilado el conocimiento disponible y se lo presenta de forma sistemática con énfasis en los datos agronómicos, las transformaciones durante la molienda, la composición química y nutricional y, finalmente, las posibilidades de utilización de cada uno. Además, se aporta una extensa bibliografía que resultará de gran utilidad para ampliar los conocimientos aquí brindados. El mundo académico e industrial podrá beneficiarse con la amplia y actualizada información sobre las nuevas tendencias y las prácticas tradicionales en el área de cereales, granos y otras fuentes alternativas de obtención de harinas.Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo (CYTED