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Subject: search.filters.subject.Stability

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    On AI-iteration process for finding fixed points of enriched contraction and enriched nonexpansive mappings with application to fractional BVPs
    (SCIK Publishing Corporation, 2024) Oboyi, J.; Orim, R. E.; Ofem, A. E.; Maharaj, A.; Narain, O. K.
    In this article, we consider the AI-iteration process for approximating the fixed points of enriched contraction and enriched nonexpansive mappings. Firstly, we prove the strong convergence of the AI-iteration process to the fixed points of enriched contraction mappings. Furthermore, we present a numerical experiment to demonstrate the efficiency of the AI-iterative method over some existing methods. Secondly, we establish the weak and strong convergence results of AI-iteration method for enriched nonexpansive mappings in uniformly convex Banach spaces. Thirdly, the stability analysis results of the considered method is presented. Finally, we apply our results to the solution of fractional boundary value problems in Banach spaces
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    Instability of ferromagnetic nanoclusters in Fe implanted amorphous SiO2
    (Elsevier, 2015) Bharuth-Ram, Krish; Doyle, Terence B.; Zhang, Kun; Masenda, Hilary; Hofsäss, Hans
    A 460 nm thick amorphous SiO2 layer, formed on a Si (100) surface by air-annealing the Si substrate at 1100oC for 24 h, was implanted with 57Fe to a fluence of 1 x 1016/cm2 at room temperature and annealed at temperatures up to 1000oC. The implanted and annealed samples were studied by conversion electron Mössbauer spectroscopy (CEMS) and magnetization measurements. The CEMS spectra up to an annealing temperature of 600oC showed the presence of a singlet due to dispersed Fe ions and paramagnetic doublets with hyperfine parameters characteristic of Fe2+ and Fe3+. The spectrum after the 1000oC annealing was dominated (> 80%) by ferromagnetic sextets, the main components of which were sextets with a hyperfine field of 320(20) kOe and 264(20) kOe, showing the formation of Fe0 clusters, in agreement with previous observations. Magnetization measurements (m(H)) on the sample after the 1000oC annealing showed a small hysteresis at 4 K and saturation magnetization with zero hysteresis at room temperature, reached with application of small external field. The CEMS measurement on this sample was repeated after storing the sample under ambient conditions for a period of 6 months. The spectrum showed complete disappearance of the ferromagnetic sextets and the presence only of paramagnetic doublets due to Fe2+. Evidently progressive oxidation of the Fe clusters had occurred. Magnetization results confirm the paramagnetic transformation of the Fe clusters.
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    Thermostable chitinase II from Thermomyces lanuginosus SSBP: Cloning, structure prediction and molecular dynamics simulations
    (Elsevier, 2015) Khan, Faez Iqbal; Govender, Algasan; Permaul, Kugen; Singh, Suren; Bisetty, Krishna
    Thermomyces lanuginosus is a thermophilic fungus that produces large number of industrially-significant enzymes owing to their inherent stability at high temperatures and wide range of pH optima, including thermostable chitinases that have not been fully characterized. Here, we report cloning, characterization and structure prediction of a gene encoding thermostable chitinase II. Sequence analysis revealed that chitinase II gene encodes a 343 amino acid protein of molecular weight 36.65 kDa. Our study reports thatchitinase II exhibits a well-defined TIM-barrel topology with an eight-stranded α/β domain. Structural analysis and molecular docking studies suggested that Glu176 is essential for enzyme activity. Folding studies of chitinase II using molecular dynamics simulations clearly demonstrated that the stability of the protein was evenly distributed at 350 K.
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    Thermostable chitinase II from Thermomyces lanuginosus SSBP : Cloning, structure prediction and molecular dynamics simulations
    (Elsevier, 2015-04-08) Khan, Faez Iqbal; Govender, Algasan; Permaul, Kugen; Singh, Suren; Bisetty, Krishna
    Thermomyces lanuginosus is a thermophilic fungus that produces large number of industrially-significant enzymes owing to their inherent stability at high temperatures and wide range of pH optima, including thermostable chitinases that have not been fully characterized. Here, we report cloning, characterization and structure prediction of a gene encoding thermostable chitinase II. Sequence analysis revealed that chitinase II gene encodes a 343 amino acid protein of molecular weight 36.65 kDa. Our study reports that chitinase II exhibits a well-defined TIM-barrel topology with an eight-stranded α/β domain. Structural analysis and molecular docking studies suggested that Glu176 is essential for enzyme activity. Folding studies of chitinase II using molecular dynamics simulations clearly demonstrated that the stability of the protein was evenly distributed at 350 K.