A chewing robot based on parallel mechanism-- analysis and design : a thesis presented in partial fulfilment of the requirements for the degree of Master of Engineering in Mechatronics at Massey University

Masticatory efficiency, dependent on number and condition of the teeth, length of time spent in chewing a bolus and the force exerted when chewing, influences an individual with the selection of food and therefore nutritionally diet. A characterisation of the masticatory efficiency could be possible with a chewing robot that simulates human chewing behaviours in a mechanically controllable way (Pap et al. 2005; Xu et al. 2005). This thesis describes such a chewing robot, developed from a biological basis in terms of jaw structure and muscles of mastication according to published articles. A six degrees of freedom parallel mechanism is proposed with the mandible as a moving platform, the skull as a fixed platform, and six actuators representing the main masticatory muscle groups, temporalis, masseter, and lateral pterygoid on the left and right side. Extensive simulations of inverse kinematics (i.e., generating muscular actuations with implementing recorded human trajectories) were conducted in SolidWorks and COSMOS/Motion to validate two mathematical models of the robot and to analyse kinematic properties. The research showed that selection of appropriate actuation systems, to achieve mandible movement space, velocity, acceleration, and chewing force, was the key challenge in successfully developing a chewing robot. Two custom designed actuation systems, for the six actuators, were developed and built. In the first approach, the muscle groups were presented as linear actuators, positioned so as to reproduce the resultant lines of action of the human muscles. However, with this design concept the spatial requirements specified from the human masticatory system made the physical building of the model impossible. The second approach used a crank mechanism based actuator. This concept did not allow a perfectly linear actuator movement that copied the muscle line of action. However, it was possible to fulfil the spatial requirements set by the human system and to allow reproduction of human chewing behaviours in relation to kinematic requirements and chewing force. The design, manufacture and testing of the entire chewing robot with crank actuators was then carried out. This included the implementation of realistic denture morphology, a mechanical jaw and the framework design for the whole system. In conclusion, this thesis research has developed successfully a mathematical and a physical robotic model. Future work on the control and sensing of the robot and design of a food retention system are required in order to fully functionalise the device

Metalloenzimek modellvegyületeinek szerkezeti jellemzése és reakciókészségük vizsgálata = Structural and Reactivity Studies on Model Compounds of Metalloenzymes

Posztdoktori pályázatom célkitűzése olyan metalloenzimek modellezése volt, amelyek képesek a dioxigén, vagy annak származékai (szuperoxid gyök-anion, hidrogén-peroxid) szelektív reakcióinak elősegítésére az aktív helyükön kötött változatos fémionok segítségével. Vastartalmú oxigenáz modellek vizsgálata során egyes esetekben peroxo- és oxo-hidas intermediereket sikerült azonosítanunk, valamint katalitikus rendszereket dolgoztunk ki alkoholok és aminosavak szelektív oxidációjára, továbbá pirokatechin oxidatív gyűrűhasítási reakciójára. A szuperoxid gyök-anion bomlását katalizáló, Mn-, Fe-, Co- és Cu-tartalmú, valamint a hidrogén-peroxid bomlását gyorsító Mn-tartalmú rendszereket is kidolgoztunk. Ezek segítségével azonosítottuk a közvetlen koordinációs szférában és a mikrokörnyezetben történt módosítások hatását az enzimutánzó aktivitásra. Általános megfigyelés volt, hogy a szuperoxid dizmutáz modelleknél fontos szerepet tölt be a fém redox-sajátsága, de egyes esetekben a különböző komplexek aktivitása közötti különbségek csak a ligandumok periferiális csoportjainak eltéréséivel voltak magyarázhatóak. Utóbbi hatások érvényesültek a hidrogén-peroxidot bontó kataláz modelleknél is. | The main objective of this postdoctoral project was the modeling of metalloenzymes that promote selective reactions of dioxygen, or reduced derivatives of dioxygen (superoxide radical anion and hydrogen peroxide) with the help of the various metal ions bound at their active sites. During the study of iron-containing oxygenase models in some cases peroxo- and oxo-bridged intermediates were identified, moreover, catalytic systems for the selective oxidation of alcohols, amino acids and for the oxidative ring-cleavage of catechol have been developed. Mn-, Fe-, Co- and Cu-containing systems to catalyze dismutation of superoxide (superoxide dismutase models), and Mn-containing models to accelerate dismutation of hydrogen-peroxide (catalase models) were also investigated. With the help of these models the effect of the modifications in the inner-sphere- and microenvironment have been elucidated. A general observation was that the redox potential of the metal center has a key role in superoxide dismutase models, but in special cases an explanation for the differing activities was only possible considering the peripheral substituents on the ligands. The latter effect was responsible for the activity of catalase models, too

Kísérlet a magyarországi választókerületek huszadik század eleji etnikai karakterének meghatározására

In this study we made an attempt to define the ethnic characters of the constituencies. We demonstrated the limits we come up against in the course of our work. Those statistical sources we have already processed up to now do not make it possible to form a true notion of the ratio of the national minorities in the population and in the group with property qualification, forming the local elite, in the constituencies. We attach importance to the solution of this problem from the point of view of the regional investigation of the results of parliamentary elections. We tried to remedy the shortage of sources by the help of statistical estimation. On the basis of the estimated ethnic character of the constituencies a map was constructed. As a result of our examination it was proved that the ethnic characters of the constituencies were parallel with the ethnic construction of the electors, consequently in our opinion the national minorities were not at a disadvantage in the course of the parliamentary elections. Additionally a map was made to show those constituencies where the parties of national minorities had success on the elections