41 research outputs found
Chimera: A Low Cost Solution to Small Satellite Space Access
In the Proceedings of the 17th Annual AIAA/USU Conference on Small Satellites, UT State University
Logan, UT, August 11 -14, 2003.The Chimera rocket was designed to enter the
small satellite market by offering an affordable and
flexible alternative to the Pegasus launch vehicle. A
number of design concepts were evaluated, and one
was selected to undergo detailed analysis. This
included disciplinary analyses in aerodynamics,
propulsion, trajectory, aeroheating, structures,
weights, operations, and cost. The baseline vehicle,
consisting of a Minuteman 2-2 first stage, a PAM-S
second stage, and a new third stage carries a 100 and
50 kg payload to a 700 km altitude, at inclinations of
60° and 110° respectively. At this point a Monte
Carlo Simulation was performed to determine how
well the system met its price goals. The baseline
vehicle fails to meet the desired launch price of $5
million to a reasonable confidence level. However,
either the implementation of a cost reduction in the
cost of the first stage, or the infusion of appropriate
structural and propellant technologies in the design of
the third stage, help to make the desired launch price
viable
Approaches in biotechnological applications of natural polymers
Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento CientfĂico e TecnolĂłgico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de NvĂel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)
The spectral treasure house of miniaturized instruments for food safety, quality and authenticity applications: A perspective
Background: Optical technologies, relying on spectral analysis, are more and more implemented in portable devices for food analysis. Thereby, each food safety, quality or authenticity provision as well as each technology requires the generation of a dedicated spectral database with reference data. Currently, knowledge on how these databases might be connected or transferred across food commodities, targeted compounds or devices are very limited. Hence, repetitive work is conducted and technologies are not optimally used. Scope and approach: This perspective focuses on the currently available technologies and approaches for data handling and database transfer across miniaturized devices and technologies for food safety, quality and authenticity assessments. Key findings and conclusions: For almost every food commodity or target compound a miniaturized spectroscopic device can be applied with the respective database to compare findings. Recent developments in optical spectroscopy allow more possibilities for their use as well as facilitate the production of portable devices. A multifunctional device hyphenating several sensors and broadening the application range is still not marketed. Newly developed software architecture, accessing and extracting data, helps to overcome sample heterogenicity or spurious measured data. In addition, several data fusion approaches using machine learning and deep learning strategies are available to fuse spectroscopic data with itself or other non-spectroscopic data. Following the research results presented in this field, spectral data can possibly be re-used and shared across instruments and locations, highly increasing the applicability of data sets. Thereby, obstacles such as policy or confidentiality are taken into account