49 research outputs found
Metamodelling and Evaluating Extreme Programming
Agile software development methods have drawn the attention of software development professionals in the past few years. Agile software development methods use iterative and incremental approaches to address the changing requirements of customers. One of the well-known agile software development methods is extreme Programming (XP) and is derived by sets of values including simplicity, communication, feedback and courage. The extreme practices, variation in composition and interaction between values and the feedback in XP have made the software system more complex and demands the improvements and evaluation framework to understand and evaluate the XP practices in a practical way.
The main aims of this study are to improve some of the extreme practices of XP through agile modeling and evaluate the XP projects using XP evaluation framework. Two research questions were set to find out the enabling and limiting factors of extreme practices of XP and the way to improve the XP software process. An interpretive research approach was used to conduct a literature review to develop the agile meta-models and evaluation framework for process improvement. The contribution of thesis work can be broadly categorized into two parts. The first part deals withmodelling the three most criticized and extreme practices (lightweight requirement, Pair Programming and onsite customer) of XP and the second part is concerned with developing the evaluation framework for XP. Use cases are collected from scenario based requirement engineering practice with stakeholder analysis to address the lightweight requirement of XP. Problems of Pair Programming are addressed by personal development traits, Distributed Pair Programming (DPP) andCollaborative Adversarial Pair (CAP) Programming models. Surrogate customers and multiple customer models are two alternatives proposed to address the problems of onsite customer in XP. The XP evaluation framework is a collection of some new and validated metrics used for evaluating XP projects, XP practices, XP products and some additional factors concerned with XP.
Asiasanat:Agile, extreme Programming (XP), interpretive research, Collaborative Adversarial Pair (CAP) and extreme practice
Various Silver Nanostructures on Sapphire Using Plasmon Self-Assembly and Dewetting of Thin Films
Application of Methods for Non-Destructive Diagnosis to Find out Defect of Rollers
Import 05/08/2014ŠEDĚNKA D. Aplikace metod nedestruktivní diagnostiky pro odhalení vad válců: diplomová práce. Ostrava: VŠB - Technická univerzita Ostrava, Fakulta strojní, Katedra výrobních strojů a konstruování, 2014, 65 s. vedoucí diplomové práce Ing. Jan Blata, Ph.D.
Diplomová práce se zabývá diagnostikou vnitřních vad válců v provoze Třineckých železáren a.s. a návrh a konstrukce rámu pro zkoumání změn magnetického pole materiálu v důsledku mechanického zatěžování. V rámci této práce byly provedeny měření
a vyhodnocení získaných dat.Šeděnka D. Application of non-destructive diagnostics for the detection of defects cylinders: thesis. Ostrava: VSB - Technical University of Ostrava, Faculty of Engineering, Department of Production Machines and Design, 2014, 65 s leading thesis Ing. Jan Blata, Ph.D.
This thesis deals with the diagnosis of internal defects of cylinders in operation as TŽ a.s. and the design and construction of the frame for examining changes in the magnetic field of the material caused by mechanical loading. In this work, measurements were made and evaluation of the data obtained.340 - Katedra výrobních strojů a konstruovánívýborn
Macromolecular design of folic acid functionalized amylopectin- albumin core-shell nanogels for improved physiological stability and colon cancer cell targeted delivery of curcumin
Nanogels have potential for encapsulating cancer therapeutics, yet their susceptibility to physiological degradation and lack of cellular specificity hinder their use as effective oral delivery vehicles. Herein, we engineered novel albumin-core with folic acid functionalized hyperbranched amylopectin shell-type nanogels, prepared through a two-step reaction and loaded with curcumin while the proteinaceous core was undergoing thermal gelation. The nanogels had a mean hydrodynamic diameter of ca. 90 nm and ζ-potential of ca. -24 mV. Encapsulation of curcumin within the nanogels was restored, up to ca. 0.05 mg mL-1, beyond which, a gradual increase in size and a decrease in ζ-potential was observed. The core-shell structures were resilient to in vitro physiological oral-gastrointestinal digestion owing to a liquid crystalline B- and V-type polymorphism in the polysaccharide shell, the latter being driven by the shell functionalization with folic acid. Additionally, these biocompatible nanogels restored stability of the encapsulated curcumin and exhibited augmented cellular uptake and retention specifically in folate receptor-positive HT29 human colon adenocarcinoma cells, inducing early-stage apoptosis. Novel insights from this study represent a promising platform for rational designing of future oral delivery systems that can surmount physiological barriers for delivering cancer therapeutics to colon cancer cells with improved stability and specificity
Metamodelling and Evaluating Extreme Programming
Agile software development methods have drawn the attention of software development professionals in the past few years. Agile software development methods use iterative and incremental approaches to address the changing requirements of customers. One of the well-known agile software development methods is extreme Programming (XP) and is derived by sets of values including simplicity, communication, feedback and courage. The extreme practices, variation in composition and interaction between values and the feedback in XP have made the software system more complex and demands the improvements and evaluation framework to understand and evaluate the XP practices in a practical way.
The main aims of this study are to improve some of the extreme practices of XP through agile modeling and evaluate the XP projects using XP evaluation framework. Two research questions were set to find out the enabling and limiting factors of extreme practices of XP and the way to improve the XP software process. An interpretive research approach was used to conduct a literature review to develop the agile meta-models and evaluation framework for process improvement. The contribution of thesis work can be broadly categorized into two parts. The first part deals withmodelling the three most criticized and extreme practices (lightweight requirement, Pair Programming and onsite customer) of XP and the second part is concerned with developing the evaluation framework for XP. Use cases are collected from scenario based requirement engineering practice with stakeholder analysis to address the lightweight requirement of XP. Problems of Pair Programming are addressed by personal development traits, Distributed Pair Programming (DPP) andCollaborative Adversarial Pair (CAP) Programming models. Surrogate customers and multiple customer models are two alternatives proposed to address the problems of onsite customer in XP. The XP evaluation framework is a collection of some new and validated metrics used for evaluating XP projects, XP practices, XP products and some additional factors concerned with XP.
Asiasanat:Agile, extreme Programming (XP), interpretive research, Collaborative Adversarial Pair (CAP) and extreme practice
Investigation on the morphological and optical evolution of bimetallic Pd-Ag nanoparticles on sapphire (0001) by the systematic control of composition, annealing temperature and time.
Multi-metallic alloy nanoparticles (NPs) can offer additional opportunities for modifying the electronic, optical and catalytic properties by the control of composition, configuration and size of individual nanostructures that are consisted of more than single element. In this paper, the fabrication of bimetallic Pd-Ag NPs is systematically demonstrated via the solid state dewetting of bilayer thin films on c-plane sapphire by governing the temperature, time as well as composition. The composition of Pd-Ag bilayer remarkably affects the morphology of alloy nanostructures, in which the higher Ag composition, i.e. Pd0.25Ag0.75, leads to the enhanced dewetting of bilayers whereas the higher Pd composition (Pd0.75Ag0.25) hinders the dewetting. Depending on the annealing temperature, Pd-Ag alloy nanostructures evolve with a series of configurations, i.e. nucleation of voids, porous network, elongated nanoclusters and round alloy NPs. In addition, with the annealing time set, the gradual configuration transformation from the elongated to round alloy NPs as well as size reduction is demonstrated due to the enhanced diffusion and sublimation of Ag atoms. The evolution of various morphology of Pd-Ag nanostructures is described based on the surface diffusion and inter-diffusion of Pd and Ag adatoms along with the Ag sublimation, Rayleigh instability and energy minimization mechanism. The reflectance spectra of bimetallic Pd-Ag nanostructures exhibit various quadrupolar and dipolar resonance peaks, peak shifts and absorption dips owing to the surface plasmon resonance of nanostructures depending on the surface morphology. The intensity of reflectance spectra is gradually decreased along with the surface coverage and NP size evolution. The absorption dips are red-shifted towards the longer wavelength for the larger alloy NPs and vice-versa
Modulation of Morphology and Optical Property of Multi-Metallic PdAuAg and PdAg Alloy Nanostructures
Abstract In this work, the evolution of PdAg and PdAuAg alloy nanostructures is demonstrated on sapphire (0001) via the solid-state dewetting of multi-metallic thin films. Various surface configurations, size, and arrangements of bi- and tri-metallic alloy nanostructures are fabricated as a function of annealing temperature, annealing duration, film thickness, and deposition arrangements such as bi-layers (Pd/Ag), tri-layers (Pd/Au/Ag), and multi-layers (Pd/Au/Ag × 5). Specifically, the tri-layers film shows the gradual evolution of over-grown NPs, voids, wiggly nanostructures, and isolated PdAuAg alloy nanoparticles (NPs) along with the increased annealing temperature. In contrast, the multi-layers film with same thickness show the enhanced dewetting rate, which results in the formation of voids at relatively lower temperature, wider spacing, and structural regularity of alloy NPs at higher temperature. The dewetting enhancement is attributed to the increased number of interfaces and reduced individual layer thickness, which aid the inter-diffusion process at the initial stage. In addition, the time evolution of the Pd150 nm/Ag80 nm bi-layer films at constant temperature show the wiggly-connected and isolated PdAg alloy NPs. The overall evolution of alloy NPs is discussed based on the solid-state dewetting mechanism in conjunction with the diffusion, inter-diffusion, alloying, sublimation, Rayleigh instability, and surface energy minimization. Depending upon their surface morphologies, the bi- and tri-metallic alloy nanostructures exhibit the dynamic reflectance spectra, which show the formation of dipolar (above 700 nm) and quadrupolar resonance peaks (~ 380 nm) and wide dips in the visible region as correlated to the localized surface plasmon resonance (LSPR) effect. An absorption dip is readily shifted from ~ 510 to ~ 475 nm along with the decreased average size of alloy nanostructures
Evolution of Ternary AuAgPd Nanoparticles by the Control of Temperature, Thickness, and Tri-Layer
Metallic alloy nanoparticles (NPs) possess great potential to enhance the optical, electronic, chemical, and magnetic properties for various applications by the control of morphology and elemental composition. This work presents the fabrication of ternary AuAgPd alloy nanostructures on sapphire (0001) via the solid-state dewetting of sputter-deposited tri-metallic layers. Based on the systematic control of temperature, thickness, and deposition order of tri-layers, the composite AuAgPd alloy nanoparticles (NPs) with various shape, size, and density are demonstrated. The metallic tri-layers exhibit various stages of dewetting based on the increasing growth temperatures between 400 and 900 °C at 15 nm tri-layer film thickness. Specifically, the nucleation of tiny voids and hillocks, void coalescence, the growth and isolated nanoparticle formation, and the shape transformation with Ag sublimation are observed. With the reduced film thickness (6 nm), tiny alloy NPs with improved structural uniformity and spatial arrangement are obtained due to enhanced dewetting. The growth trend of alloy NPs is drastically altered by changing the deposition order of metallic tri-layers. The overall evolution is governed by the surface diffusion and inter-mixing of metallic atoms, Rayleigh-like instability, surface and interface energy minimization, and equilibrium state of the system. The UV-VIS-NIR reflectance spectra reveal the formation of an absorption band and reflectance maxima at specific wavelengths based on the morphology and composition of AuAgPd alloy NPs. In addition, Raman spectra analysis shows the modulation of intensity and peak position of natural vibration modes of sapphire (0001)
Structure-based virtual screening, molecular docking, ADMET and molecular simulations to develop benzoxaborole analogs as potential inhibitor against Leishmania donovani trypanothione reductase
Visceral leishmaniasis (VL) is the most fatal form of leishmaniasis and it affects 70 countries worldwide. Increasing drug resistant for antileishmanial drugs such as miltefosine, sodium stibogluconate and pentamidine has been reported in the VL endemic region. Amphotericin B has shown potential antileishmanial activity in different formulations but its cost of treatment and associated nephrotoxicity have limited its use by affected people living in the endemic zone. To control the VL infection in the affected countries, it is necessary to develop new antileishmanial compounds with high efficacy and negligible toxicity. Computer aided programs such as binding free energy estimation; ADMET prediction and molecular dynamics simulation can be used to investigate novel antileishmanial molecules in shorter duration. To develop antileishmanial lead molecule, we performed standard precision (SP) docking for 1160 benzoxaborole analogs along with reference inhibitors against trypanothione reductase of Leishmania parasite. Furthermore, extra precision (XP) docking, ADMET prediction, prime MM-GBSA was conducted over 115 ligands, showing better docking score than reference inhibitors to get potential antileishmanial compounds. Simultaneously, area under the curve (AUC) was estimated using ROC plot to validate the SP and XP docking protocol. Later on, two benzoxaborole analogs with best MM-GBSA G-bind were subjected to molecular simulation and docking confirmation to ensure the ligand interaction with TR. The presented drug discovery based on computational study confirms that BOB27 can be used as a potential drug candidate and warrants further experimental investigation to fight against VL in endemic areas
Morphological and optical properties of PdxAg1-x alloy nanoparticles
Alloy nanoparticles (NPs) can offer a wide range of opportunities for various applications due to their composition and structure dependent properties such as multifunctionality, electronic heterogeneity, site-specific response, and multiple plasmon resonance bands. In this work, the fabrication of self-assembled PdxAg1-x NPs alloy nanostructures with distinct size, density, shape, and composition is demonstrated via the solid-state dewetting of sputtered Pd/Ag thin films on c-plane sapphire. The initial stage of bilayer dewetting exhibits the nucleation of voids, followed by the expansion of voids and cluster breakdown and finally shape transformation along with the temperature control. Bilayer composition shows a substantial influence on the dewetting such that the overall dewetting is enhanced along with the increased Ag composition, i.e. Pd0.25Ag0.75 > Pd0.5Ag0.5 > Pd0.75Ag0.25. On the other hand, the size and density of NPs can be efficiently controlled by varying the initial thickness of bilayers. Reflectance peaks in UV and near-infrared (NIR) regions and a wide absorption band in the visible region arisen from the surface plasmon resonance are observed in reflectance spectra. The peak intensity depends on the composition of PdxAg1-x NPs and the NIR peaks gradually blue-shift with the size decrement