Highly effective and power efficient biological mechanisms are common in nature. The use of biological design principles in engineering domain requires adequate training in both engineering and biological domains. This requires cooperation between biologists and engineers that leads to a new discipline of biomimetic science and engineering. Biomimetic is the abstraction of good design from nature. Because of the fact that biomimetic design has an important place in mechatronic applications, this study is directed towards biomimetic design of grasshopper-like jumping mechanism. A biomimetic design procedure is developed and steps of the procedure have followed through all the study. A literature survey on jumping mechanisms of grasshoppers and jumping robots and bio-robots are done and specifically apteral types of grasshoppers are observed. After the inspections, 2D and 3D mathematical models are developed representing the kinematics and dynamics of the hind leg movements. Body-femur, femur-tibia and tibia-ground angles until take-off are obtained from the mathematical leg models. The force analysis of the leg models with artificial muscles and biological muscles are derived from the torque analysis. A simulation program is used with a simple model for verification. The horizontal displacement of jumping is compared with the data obtained from the simulation program and equation of motion solutions with and without air resistance. Actuators are the muscles of robots that lead robots to move and have an important place in robotics. In this scope, artificial muscles are studied as a fourth step of biomimetic design. A few ready-made artificial muscles were selected as an actuator of the grasshopper-like jumping mechanism at the beginning of the study. Because of their disadvantages, a new artificial muscle is designed and manufactured for mini bio-robot applications. An artificial muscle is designed to be driven by an explosion obtained due to the voltage applied in a piston and cylinder system filled with dielectric fluid. A 3.78-mm diameter Teflon piston is fitted with a clearance into a Teflon cylinder filled with a 25.7- mm fluid height and maximum 225 V is applied to the electrodes by using an electrical discharge machine (EDM) circuit. The force on the piston is measured by using a set-up of Kistler piezoelectric low level force sensor. The data obtained from the sensor is captured by using an oscilloscope, a charge meter, and a GPIB connecting card with software, Agilent. From the experiments, the new artificial muscle force is about 300 mN giving a 38:1 force to weight ratio and percentage elongation is expected to be higher than that of the natural muscles and the other artificial muscles. From the force analysis of the leg model, it is shown that the measured force is not enough alone for jumping of an about 500 mgr body. An additional artificial muscle or a single muscle designed with the same operating principle giving higher force to weight ratio is recommended as a future study.

Thesis (doctoral)--Stockholm University, 1992. / Includes bibliographical references.

Thesis (Ph.D. (Zoology & Entomology)) - Rhodes University, 2009.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / An average of 20,000 species of the Order Orthoptera are worldwide known and have great importance due to the economic damage caused by some species in agricultural areas. Thus, this study aimed to characterize the community of Acridoidea through biodiversity and faunal analysis in order to determine the optimum size of the sample as well as the ideal time of collection. Three experiments were conducted in the municipality of Sao Sepe, Brazil, one for each of the goals. Samples were collected between January and May 2009 in two areas of native grassland. With the purpose of catching insects, we used a data collection network, proposed by Costa and Carvalho, with which he toured different sample sizes (distance). The collected samples were placed in plastic bags and taken to the Laboratory of Entomology of the Federal University of Santa Maria for screening. They have afterwards been referred to the Laboratory of Entomology of the Bioscience faculty of PUC, Brazil, and identified by Professor Maria Katia Matiotti Costa to the taxonomic category of species. 2913 copies were collected, distributed into 22 (twenty two) species, belonging to 17 (seventeen) genera, and three (3) families as it follows: Acrididae, and Proscopiidae Romaleidae. The species Scotussa cliens (Stål, 1860), Dichroplus silveiraguidoi Liebermann, 1956 and Notopomala glaucipes (Rehn, 1905), were classified as dominant, common, and abundant. All species showed accidental constancy. The sampling method developed by Costa and Carvalho was efficient. The optimum size of the sample was 25m as it showed the largest number of specimens and species diversity. The best time of collection was by 1:30 p.m., where the greatest number of samples and species diversity has been collected. / Cerca de 20 mil espécies da Ordem Orthoptera são conhecidas mundialmente e apresentam importância relevante, devido aos danos econômicos causados por algumas espécies em áreas agrícolas. Assim, esse estudo teve como objetivo caracterizar a comunidade de acridóideos, através da análise faunística e da biodiversidade; determinar o tamanho ideal de amostra e verificar o horário ideal de coleta. Foram realizados três experimentos no Município de São Sepé, RS, um para cada um dos objetivos propostos. As coletas foram realizadas entre os meses de janeiro e maio de 2009 em duas áreas de campo nativo. Para a captura dos insetos, utilizou-se uma rede de coleta, proposta por Costa e Carvalho, com a qual se percorreu diferentes tamanhos de amostra (distância percorrida). Os exemplares coletados foram acondicionados em sacos plásticos e levados ao Laboratório de Entomologia da UFSM para triagem. Após, foram encaminhados ao Laboratório de Entomologia da Faculdade de Biociências da PUC, RS, para serem identificados pela Profª Maria Kátia Matiotti da Costa até a categoria taxonômica de espécie. Foram coletados 2913 exemplares, distribuídos em 22 (vinte e duas) espécies, pertencentes a 17 (dezessete) gêneros e 3 (três) famílias sendo: Acrididae, Proscopiidae e Romaleidae. As espécies Scotussa cliens (STÅL, 1860), Dichroplus silveiraguidoi (LIEBERMANN, 1956) e Notopomala glaucipes (REHN, 1905), foram classificadas como dominantes, frequentes e abundantes. Todas as espécies apresentaram constância acidental. O método de coleta desenvolvido por Costa e Carvalho mostrou-se eficiente. O tamanho ideal de amostra foi o de 25m, pois apresentou o maior número de exemplares e diversidade de espécies. O melhor horário de coleta foi as 13:30, onde foi coletado o maior número de exemplares e diversidade das espécies.

No description available.

Tallgrass prairie restoration is an important conservation activity in rural areas. However, little is known about prairie restoration in urban environments. The overall objective of this study was to characterize and better understand urban prairie restoration. This was carried out through an examination of 29 restoration sites within Winnipeg, Manitoba. The results indicated that actively restored urban prairies were successful and high in diversity. Multiple attributes of the restorations were examined as indicators of success including vegetation, the propagule bank and insects. However, not all attributes delivered equivocal results. This suggests that multiple measures should be used to assess a restoration site. Anthropogenic and biophysical variables were found to influence vegetation of the restorations equally, highlighting the importance of incorporating a human component in urban ecological research. These urban restorations were seen to surpass larger rural restorations in quality; thus, efforts should be made to increase their prevalence. / February 2008

Formulations of aqueous neem extracts were sprayed in field experiments. Results showed that a 0.5% and 1% concentrations were effective in reducing grasshopper feeding and diminishing damage caused by the millet stemborer, C. ignefusalis. In 1988, neem diminished egg-laying and mine damage by the headminer, H. albipunctella, but no data were available for 1989 because of the low infestation levels of this pest. / Neem exhibited some systemic activity. Soil applied neem kernel powder partially protected millet against K. angulifera and C. ignefusalis. Neem treated plots yielded more grain and suffered less damage by insect pests than four different cultural practices. Only the addition of fertilizer was superior to neem in reducing yield losses but it was inferior in limiting pest losses. / Experiments to test the residual activity of neem showed that this botanical insecticide can effectively protect millet against K. angulifera for at least seven days, and possibly longer if ultra-violet rays and rainfall are not prevalent. Analysis of plant selection behavior of K. angulifera showed that neem is an antifeedant rather than a repellent. On first to third instar nymphs, growth regulating activity expressed as a difficulty in molting or an absence of sclerotization may occur. Topical applications of neem to the stemborer, C. ignefusalis, also caused growth abnormalities, mostly molting disturbances. Treated larvae that reached the adult stage were malformed. / This research indicates that neem based insecticides offer considerable promise for Sahelian farmers for protecting millet crops. It is effective against K. angulifera, but less effective against the stemborer, C. ignefusalis. Although the data obtained for H. albipunctella in 1988 was promising, it was insufficient to reach any conclusions regarding neem's efficacy with respect to this pest.

Tallgrass prairie restoration is an important conservation activity in rural areas. However, little is known about prairie restoration in urban environments. The overall objective of this study was to characterize and better understand urban prairie restoration. This was carried out through an examination of 29 restoration sites within Winnipeg, Manitoba. The results indicated that actively restored urban prairies were successful and high in diversity. Multiple attributes of the restorations were examined as indicators of success including vegetation, the propagule bank and insects. However, not all attributes delivered equivocal results. This suggests that multiple measures should be used to assess a restoration site. Anthropogenic and biophysical variables were found to influence vegetation of the restorations equally, highlighting the importance of incorporating a human component in urban ecological research. These urban restorations were seen to surpass larger rural restorations in quality; thus, efforts should be made to increase their prevalence.

Tallgrass prairie restoration is an important conservation activity in rural areas. However, little is known about prairie restoration in urban environments. The overall objective of this study was to characterize and better understand urban prairie restoration. This was carried out through an examination of 29 restoration sites within Winnipeg, Manitoba. The results indicated that actively restored urban prairies were successful and high in diversity. Multiple attributes of the restorations were examined as indicators of success including vegetation, the propagule bank and insects. However, not all attributes delivered equivocal results. This suggests that multiple measures should be used to assess a restoration site. Anthropogenic and biophysical variables were found to influence vegetation of the restorations equally, highlighting the importance of incorporating a human component in urban ecological research. These urban restorations were seen to surpass larger rural restorations in quality; thus, efforts should be made to increase their prevalence.

No description available.