Missile Longitudinal Dynamics Control Design Using Pole Placement and LQR Methods

In high-maneuvering missile systems, with severe restrictions on actuator energy requirements, it is desirable to achieve the required performance with least actuation effort. Linear Quadratic Regulator (LQR) has been in literature for long and has proven it’s mettle as an optimal controller in many benign aerospace applications and industrial applications where the response times of the plant, in most cases, are seen to be greater than 10 seconds. It can be observed in the literature that LQR control methodology has not been explored enough in the tactical missile applications where requirement of very fast airframe response times are desired, typically of the order of milliseconds. In the present research, the applicability of LQR method for one such agile missile control has been critically explored. In the present research work, longitudinal dynamic model of an agile missile flying at high angle of attack regime has been established and an optimal LQR control solution has been proposed to bring out the required performance demanding least control actuator energy. A novel scheme has been presented to further optimise the control effort, which is essential in this class of missile systems with space and energy constraints, by iteratively computing optimal magnitude state weighing matrix Q and control cost matrix R. Pole placement design techniques, though extensively used in aerospace industry because of ease of implementation and proven results, do not address optimality of the system performance. Hence, a comparative study has been carried out to verify the results of LQR against pole placement technique based controller. The efficacy of LQR based controller over pole placement design techniques is successfully established with minimum control energy requirement in this paper. Futuristic high maneuvering, agile missile control design with severe space and energy constraints stand to benefit incorporating the controller design scheme proposed in this paper.&nbsp

Anti-inflammatory, antinociceptive, and antipyretic effects of methanol extract of Cariniana rubra stem bark in animal models

Schmeda-Hirschmann, G (Schmeda-Hirschmann, Guillermo) Univ Talca, IQRN, Talca, ChileCariniana rubra Miers (Lecythidaceae), popularly known as "jequitiba-vermelho", is a large Brazilian tree whose bark is used in infusion and decoction for the treatment of inflammatory conditions. This study aims to assess the anti-inflammatory, antinociceptive, and antipyretic effects of Cariniana rubra methanolic stem bark extract (EMCr) using experimental animals. Anti-inflammatory activity of EMCr was tested on carrageenan and dextran-induced rat paw edema, carrageenan-induced pleurisy in rats and acetic acid-increase vascular permeability in mice. Antinociceptive and antipyretic activities were evaluated using acetic acid-induced writhing, formalin and hot-plate tests in mice, as well as brewer's yeast-induced pyrexia in rats. The extract inhibitied carrageenan and dextran-induced edema, reduced exudate volume and leukocyte migration on the carrageenan-induced pleurisy and on the vascular permeability increase induced by acetic acid. The EMCr inhibited nociception on the acetic acid-induced writhing and in the second phase of formalin test, and decreased rectal temperature. It was, however, inactive against thermal nociception. Phytochemical analysis with EMCr showed the occurrence of saponins, triterpenes, sterols and phenolic compounds. Phytosterols (beta-sitosterol, stigmasterol), pentacyclic triterpenes (alpha- and beta-amyrin as a mixture), arjunolic acid, a phytosterol glycoside (sitosterol 3-O-beta-D-glucopyranoside), and triterpenoid saponins (28-beta-glucopyranosyl-23-O-acetyl arjunolic acid; 3-O-beta-glucopyranosyl arjunolic acid and 28-O-[alpha-L-Rhamnopyranosyl-(1 -> 2)-beta-glucopyranosyl]-23-O-acetyl arjunolic acid) were the main identified compounds. It can be presumed that EMCr caused their effects by inhibiting the liberation and/or action of different inflammatory mediators. These findings support the traditional use of Cariniana rubra preparations to treat inflammation

Biosourced graphitic nanoparticle loaded hyperbranched polyurethane composites - Application as multifunctional high-performance coatings

The present work reports the development of a novel nitrogen rich hyperbranched polyurethane-urea nanocomposite using bio-sourced graphitic nanoparticles as an effective filler. Initially, a nitrogen rich hyperbranched polyol is obtained by a two step polycondensation reaction between castor oil derived sebacic acid and triethanolamine. The formation of the hyperbranched polyol was confirmed by using various spectroscopic techniques like FTIR, 1H NMR, 13C NMR and ESI-MS. The resulting hyperbranched polyol with 80% degree of branching was further reacted with carboxyl terminated graphitic nanoparticles in different weight percentages (0, 0.1 and 0.5% with respect to polyol weight) along with a diisocyanate (maintaining an OH:NCO ratio of 1:1.2) in order to get polyurethane-urea graphitic nanoparticle hybrid nanocomposites. The results suggest that the incorporation of graphitic nanoparticles improves the thermo-mechanical properties, hydrophobic nature, and bacterial and corrosion resistance of the polyurethane nanocomposite. It is seen that a minuscule incorporation of 0.5% graphitic nanoparticles into the polyurethane matrix improves the storage modulus from 365 to 996 MPa, the glass transition temperature from 67°C to 95°C, the water contact angle from 50° to 80° and reduces the corrosion rate from 9.2 × 10-3 to 5.29 × 10-5 mm per year in comparison with neat polyurethane. All these improvements in properties are accredited to the covalent linkage, geometry and uniform distribution of graphitic nanoparticles with the polyurethane matrix. In addition, all the polyurethane hybrids show good stability against various bacterial stains

Plantas medicinais usadas nos distúrbios do trato gastrintestinal no povoado Colônia Treze, Lagarto, SE, Brasil Medicinal plants used for aliments of the gastro-intestinal tract at Colonia Treze village, Lagarto Municipality, Sergipe State, Brazil

Os modelos de desenvolvimento sócio-econômicos adotados pela sociedade humana refletem diferentes formas de relacionamento com a natureza, as quais no paradigma vigente têm levado à grande perda de recursos naturais. Na esfera dessa relação, a conservação e preservação da biodiversidade da flora medicinal torna-se fundamental, pela importância que as plantas medicinais assumem como potencial genético para o desenvolvimento de novas drogas, e como acesso primário à saúde para muitas comunidades. Utilizando a abordagem etnofarmacológica na pesquisa de plantas medicinais, este trabalho teve por objetivo estudar as plantas medicinais utilizadas popularmente contra distúrbios do trato gastrintestinal no povoado Colônia Treze em Lagarto, SE, comunidade que tem o uso popular das plantas medicinais inserido em sua cultura. Sua metodologia abrangeu trabalho de campo na comunidade, adotando o método etnográfico qualitativo rápido. A amostra foi composta por líderes da comunidade, usuários de plantas e praticantes da medicina popular. Baseando-se nas indicações populares sobre o uso das plantas medicinais, selecionaram-se oito plantas que foram submetidas aos experimentos farmacológicos. As plantas testadas no Modelo de Trânsito Intestinal não produziram alteração na motilidade. Já as submetidas ao Modelo de Indução de Lesão Gástrica aguda, mostraram-se efetivas na atividade antiulcerogênica. A partir destes resultados propõem-se estratégias de desenvolvimento local para esta comunidade, que aliem a conservação da flora medicinal à melhoria de sua qualidade de vida.<br>Models of socioeconomic development adopted by human societies reflect different ways of relating to Nature, which, given the present paradigm, have evolved towards great natural-resource loss. Within the sphere of this relationship, both the conservation and preservation of medicinal-plant biodiversity are fundamental because of the importance of medicinal plants as genetic potential for the development of new drugs, and as the primary access to health care for many communities. Using an ethnopharmacological approach in the study of medicinal plants, this work aimed to study the medicinal plants popularly used for gastro-intestinal tract ailments, at Colonia Treze village, in Lagarto/Sergipe, since this community is culturally attuned to the use of medicinal plants. Methodology consisted of field work within the community, adopting the ethnographic Rapid Assessment Procedure. The sample was composed of community leaders, plant users and practitioners of folk medicine. Based on their indications of medicinal-plant use, eight plants were selected and subject to pharmacological experimental tests. Plants tested by the Intestinal Transit Model did not provoke alterations in motility. However, those that underwent the Acute Gastric Lesion Induction Model proved to be effective in anti-ulcerogenic activity. Based on these results, strategies for local development at the community level are proposed, which will tie the conservation of medicinal flora to improvements in life quality