Guidance and control strategies for aerospace vehicles

A simplified method of matched asymptotic expansions was developed where the common part in composite solution is generated as a polynomial in stretched variable instead of actually evaluating the same from the outer solution. This methodology was applied to the solution of the exact equations for three dimensional atmospheric entry problems. Compared to previous works, the present simplified methodology yields explicit analytical expressions for various components of the composite solution without resorting to any type of transcendental equations to be solved only by numerical methods. The optimal control problem arising in the noncoplanar orbital transfer employing aeroassist was also addressed

Guidance and control strategies for aerospace vehicles

The optimal control problem arising in coplanar orbital transfer employing aeroassist technology and the fuel-optimal control problem arising in orbital transfer vehicles employing aeroassist technology are addressed

An investigation on the energy recovery potential of sewage sludge in Malaysia through biogas generation

In a world where energy is being a primary concern, extracting energy from waste has been a common interest in world today which is striving for energy. The research title is ―An investigation on the energy recovery potential of sewage sludge in Malaysia through biogas generation”. This research will be focused mainly on recovering energy through biogas generation while using sewage sludge as the feed source. Sewage sludge is basically produced from the treatment of domestic wastewater and consists of two basic forms which is raw primary sludge (basically faecal material) and secondary sludge (a living ‗culture‘ of organisms that help remove contaminants from wastewater before it is returned to rivers or the sea). The material that remains after the digestion process is referred to as biosolids. The main purpose of coming up with this research is because the current cost of disposing sewage sludge in Malaysia is around 1billion ringgit annually. There is also very limited landfill land that is available now in Malaysia for the sludge disposal. Sludge cannot be dispose freely and need a proper disposal method as it contains bacteria and can cause health problem. Based on all this causes, this research concentrate on reducing the sludge content and at the same time extract energy from the waste which is in this case is sewage sludge. Based on the background study, anaerobic digestion method has been identified as the most efficient process that can be applied to recover energy from domestic sewage sludge and at the same time reduce the sludge content as well. This finding is explained in the report below. Anaerobic digestion is basically a natural process that occurs from the breakdown of organic material by micro-organisms in the absence of oxygen. This digestion process reduces the primary sludge content, and the byproduct of this will be biogas. In order to carry out this project, a simulation of anaerobic digestion plant will be designed using HYSYS simulation. In this research, this simulation will be studied thoroughly to get the most output from the applied feed rate. Later from the simulation the amounts of electrical energy that can be recovered from the biogas will be calculated. The outcome of this result will conclude the potential of recovering energy from sewage sludge. Therefore, this study of energy recovery potential through biogas generation by using sewage sludge becomes economically and ecologically attractive for us in Malaysia

Guidance and Control strategies for aerospace vehicles

A neighboring optimal guidance scheme was devised for a nonlinear dynamic system with stochastic inputs and perfect measurements as applicable to fuel optimal control of an aeroassisted orbital transfer vehicle. For the deterministic nonlinear dynamic system describing the atmospheric maneuver, a nominal trajectory was determined. Then, a neighboring, optimal guidance scheme was obtained for open loop and closed loop control configurations. Taking modelling uncertainties into account, a linear, stochastic, neighboring optimal guidance scheme was devised. Finally, the optimal trajectory was approximated as the sum of the deterministic nominal trajectory and the stochastic neighboring optimal solution. Numerical results are presented for a typical vehicle. A fuel-optimal control problem in aeroassisted noncoplanar orbital transfer is also addressed. The equations of motion for the atmospheric maneuver are nonlinear and the optimal (nominal) trajectory and control are obtained. In order to follow the nominal trajectory under actual conditions, a neighboring optimum guidance scheme is designed using linear quadratic regulator theory for onboard real-time implementation. One of the state variables is used as the independent variable in reference to the time. The weighting matrices in the performance index are chosen by a combination of a heuristic method and an optimal modal approach. The necessary feedback control law is obtained in order to minimize the deviations from the nominal conditions

Vrou is Gif: The representation of violence against women in Margie Orford’s Clare Hart novels

This article takes as its starting point that crime fiction is a public and political response to gender-based violence. Using the methods of both discourse analysis and literary analysis of the crime fiction genre, the novels of Margie Orford, internationally acclaimed crime author and patron of Rape Crisis, are examined for their representations of violence against women, and the role played by these representations in Orford’s overall feminist project in the Clare Hart series. The article also considers theories about gender-based violence which link male violence to a purported crisis in the established gender order of South Africa. An attempt is made to understand the relationship between fictionalised representations of violence and the ‘banality’ of real-life violence. Finally, Hart, Orford’s hard-boiled female detective figure, is assessed to determine whether this character constitutes a significant feminist achievement that contributes to discourses which counter gender-based violence.Keywords: South Africa; crime fiction; gender-based violence; representation; feminist detectiv

Evaluation of Turmeric (Curcuma longa L.) Varieties for Rainfed Cultivation

Field experiments were carried out for two years at Agricultural Research Station, Seethampeta, Srikakulam Dist., Andhra Pradesh, to identify suitable turmeric cultivars for tribal areas of North Coastal Andhra Pradesh for rainfed cultivation. Ten cultivars were screened for their performance for comparison with the most popular local cultivar, 'Seethampeta local'. All the cultivars tested outperformed the local cultivar. Cultivars PTS-24 and CLL-326 were better in terms of plant height (93.43cm and 92.70cm, respectively) and mean number of tillers / plant (2.16 and 2.21 respectively). Per cent curing was highest in PTS-38 (28.5), followed by PTS-24 (25.7) and CLL-326 (25.2). Cultivars PTS-24 and CLL-326 recorded highest mean yield of both fresh and cured rhizomes. Yield of fresh rhizomes was positively correlated to number of tillers and number of leaves, while, yield of cured rhizomes was significantly influenced by per cent curing and number of leaves. Cultivars PTS-24 and CLL-326 recorded highest mean yield (23.08 t ha-1 and 22.93 t ha-1, respectively) and were identified as suitable varieties for rainfed cultivation in tribal areas of North Coastal Andhra Pradesh

Inflaton Decay in an Alpha Vacuum

We study the alpha vacua of de Sitter space by considering the decay rate of the inflaton field coupled to a scalar field placed in an alpha vacuum. We find an {\em alpha dependent} Bose enhancement relative to the Bunch-Davies vacuum and, surprisingly, no non-renormalizable divergences. We also consider a modified alpha dependent time ordering prescription for the Feynman propagator and show that it leads to an alpha independent result. This result suggests that it may be possible to calculate in any alpha vacuum if we employ the appropriate causality preserving prescription.Comment: 16 pages, 1 figure, Revtex 4 preprin

Laryngeal nerve “anastomoses”

Laryngeal nerves have been observed to communicate with each other and forma variety of patterns. These communications have been studied extensively and have been of particular interest as it may provide an additional form of innervation to the intrinsic laryngeal muscles. Variations noted in incidence may help explain the variable position of the vocal folds after vocal fold paralysis. This study aimed to examine the incidence of various neural communications and to determine their contribution to the innervation of the larynx. Fifty adult cadaveric en-bloc laryngeal specimens were studied. Three different types of communications were observed between internal and recurrent laryngeal nerves viz. (1) Galen’s anastomosis (81%): in 13%, it was observed to supply the posterior cricoarytenoid muscle; (2) thyroarytenoid communication (9%): this was observed to supply the thyroarytenoid musclein 2% of specimens and (3) arytenoid plexus (28%): in 6%, it supplied a branch tothe transverse arytenoid muscle. The only communication between the externaland recurrent laryngeal nerves was the communicating nerve (25%). In one lefthemi-larynx, the internal laryngeal nerve formed a communication with the externall aryngeal nerve, via a thyroid foramen. The neural communications that exist in the larynx have been thought to play a role in laryngeal innervation. The results of this study have shown varying incidences in neural communications. Contributions fromthese communications have also been noted to various in trinsic laryngeal muscles which may be a possible factor responsible for the variable position of the vocalfolds in certain cases of vocal fold paralysis

Synthetic aerial image generation for miniature aerial system

This paper presents a computer vision based method which generates a synthetic image of the earth as would be viewed by an aerial camera. The method takes geo-referenced, ortho-rectified aerial image database as the source and using a pinhole perspective camera model generates the synthetic image. The method requires the position and attitude of the camera, which act as the extrinsic parameters for the camera model. The intrinsic parameters are chosen to emulate a real camera. Finally, the results of synthetic aerial image generation implemented on MATLAB are presente

A STUDY ON KANDUGHNA TAILA IN FILARIAL LYMPHANGITIS AND ULCERS

The disease Shlipada is very common in Andhra Pradesh Coastal belts. The chronic filarial patients used to suffer from acute periodic episodes. During these acute periodic episodes majority of the filarial patients develop lymphangitis (inflammation of lymphatic vessel), wounds and ulcers in affected legs. Some of the patients develop oozing blisters and pustules. Patients with these acute symptoms suffer from severe pain and tenderness and un-hygiene may lead to secondary bacterial infections. These periodic episodes often end with fibrosis and permanent swelling (Lymphedema). Many Ayurvedic herbal and herbo-mineral drugs were successfully used internally to reduce chronic filarial swelling (lymphedema), but there is an ultimate need to find an external application to reduce the acute symptoms like lymphangitis, wounds and ulcers. Kandughna taila is a Ayurvedic herbal oil prepared from Kandughna Dashaimani (a group of 10 drugs indicated in Itching) of Caraka samhita. This Kandughna taila was selected to study externally on Filarial patients. As a part of PhD study to find the efficacy of drug this oil alone was used in 28 patients in an open clinical trail. Encouraging results were observed during and after 30 days of treatment. Out of 28 cases, 8 (28.8%) got good response, 15 (53.6%) got fair response, 2 (7.1%) got poor response and 3 (10.7%) cases did not show any response. Overall 63.68% relief was found in all acute clinical parameters. Parameter wise 62% of relief in lymphangitis, 56.1% in pain, 62.5% in tenderness, 77.78% relief in wound/ ulcer were found. In statistical analysis based paired t-test relief on acute symptoms like lymphangitis, pain, tenderness, wound were found highly significant (P<0.0001). Statistically overall effect of treatment on acute symptoms was also found highly significant (P<0.0001)