Zamreženje celuloznih tekstilnih substratov z nenasičenimi karboksilnimi kislinami Vera Vivod
, 2009, master's thesis
Abstract: V magistrski nalogi smo proučevali uporabo mešanice nenasičene bifunkcionalne karboksilne kisline (maleinska kislina) in natrijevega hidrogen fosfata I kot reagenta za doseganje polifunkcionalnosti bombažnega substrata. Preiskovali smo kemijske reakcije med maleinsko kislino (MA) in natrijevim hidrogen fosfatom I (SHP) v trdnem stanju pri povišani temperaturi, nadalje smo proučevali proces zamreženja MA in adicije SHP na dvojno C=C vez MA, ki je vezana na bombaž.
Potek kemijskih reakcij mešanic MA in SHP v trdnem stanju smo proučevali z FT-Raman in ATR FT-IR spektroskopijo. Pri tem smo raziskali vliv temperature in časa segrevanja in molarnih razmerij med obema komponentama mešanice na mehanizem reakcije.
Bombažni substrat smo obdelali z obdelovalnimi kopelmi, ki so vsebovale MA/SHP. Proučevali smo vpliv molarnih razmerij med obema komponentama v obdelovalni kopeli na učinkovitost apreture. Z MA/SHP sistemom obdelan celulozni tekstilni material je lahko potencialeno ognjevaren in ima istočasno vrhunske lastnosti (nemečkljivost, dimenzijska stabilnost). Mehanizem estrenja MA na hidroksilne skupine celuloze in adicija SHP na C=C dvojno vez maleinske kisline smo proučevali z ATR-FT IR in Raman spektroskopijo. Vsebnost fosforja na obdelanem tekstilnem substratu smo določili z ICP atomsko emisijsko spektroskopijo. Končni rezultat zamreženja hidroksilnih skupin celuloze z MA/SHP sistemom smo ovrednotili z merjenjem kotov razgubanja. Ugotovili smo, da lahko sistem MA/SHP uporabimo kot potencialni ognjevarni reagent, saj vsebuje fosfor in istočasno lahko tako obdelanemu materialu izboljšamo nemečkljivost.
Iz rezultatov raziskovalnega dela lahko zaključimo, da poteka zamreženje bombažnega celuloznega substrata tako, da se natrijev hidrogen fosfat I adicijsko veže na dvojni C=C vezi maleinskih kislin, ki so vezane na hidroksilne skupine celuloze preko esternih vezi, pri čemer pride do premreženja.
Keywords: zamreženje, nenasičene karboksilne kisline, celuloza, FT-Raman spektroskopija, FT-IR spektroskopija
Published: 06.04.2009; Views: 2641; Downloads: 190
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Exocytosis of insulin in vivo maturation of mouse endocrine pancreasAldo Rozzo
, Tiziana Meneghel-Rozzo
, Saška Lipovšek Delakorda
, Shi-Bing Yang
, Marjan Rupnik
, 2009, published scientific conference contribution
Abstract: The aim of this study was to define when an insulin-positive cell becomes functional in vivo and starts to exocytose insulin in a regulated nutrient-dependent manner. Insulin-positive cells appear in embryonic life (midgestation) and complete their maturation, presumably around birth. In order to work with embryonic and newborn endocrine pancreas, we used organotypic slices. The mouse embryonic pancreas slices show high basal insulin release that is not further elevated by high glucose levels. Despite the presence of functional voltage-activated ion channels, the cells are not electrically active in the presence of secretagogues. At birth, the high basalinsulin release drops and, after postnatal day 2, the insulin-positive cells show both adult-like bursting electrical activity and hormone release induced by high glucose levels. These properties allowed us to define them as beta cells. Despite the apparent stability of the transcription factor profile reported in insulin-positive cells during late-embryonic life, functional beta cells appear only 2 days after birth.
Keywords: cell biology, insulin release, embrios, newborn, beta-cell maturation, developing pancreas
Published: 07.06.2012; Views: 720; Downloads: 13
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A COMPREHENSIVE REVIEW OF BAT ALGORITHMS AND THEIR HYBRIDIZATIONIztok Fister
, 2013, master's thesis
Abstract: Swarm intelligence is a modern and efficient mechanism for solving hard problems in computer science, engineering, mathematics, economics, medicine and optimization. Swarm
intelligence is the collective behavior of decentralized and self-organized systems. This research area is a branch of artificial intelligence and could be viewed as some kind of
family relationship with evolutionary computation because both communities share a lot of common characteristics. To date, a lot of swarm intelligence algorithms have been
developed and applied to several real-world problems. The main focus of this thesis is devoted to the bat algorithm which is a member of the swarm intelligence community, as
developed recently. In line with this, a comprehensive analysis of papers was performed tackling this algorithm. Some hybridizations of the original algorithm were proposed because the preliminary results of this algorithm regarding the optimization of benchmark functions with higher dimensions had not too promising. Extensive experiments showed that the hybridizing the original bat algorithm has beneficial effects on the results of the original bat algorithm. Finally, an experimental study was performed during which we researched for the dependence of an applied randomized method on the results of the original bat algorithm. The results of this study showed that selecting the randomized method had a crucial impact on the results of the original bat algorithm and that the bat algorithm using Levy flights is also suitable for solving the harder optimization problems.
Keywords: swarm intelligence, evolutionary computation, bat algorithm, hybridization, review
Published: 06.09.2013; Views: 2195; Downloads: 219
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Towards the novel reasoning among particles in PSO by the use of RDF and SPARQLIztok Fister
, Xin-She Yang
, Karin Ljubič Fister
, Dušan Fister
, Janez Brest
, Iztok Fister
, 2014, original scientific article
Abstract: The significant development of the Internet has posed some new challenges and many new programming tools have been developed to address such challenges. Today, semantic web is a modern paradigm for representing and accessing knowledge data on the Internet. This paper tries to use the semantic tools such as resource definition framework (RDF) and RDF query language (SPARQL) for the optimization purpose. These tools are combined with particle swarm optimization (PSO) and the selection of the best solutions depends on its fitness. Instead of the local best solution, a neighborhood of solutions for each particle can be defined and used for the calculation of the new position, based on the key ideas from semantic web domain. The preliminary results by optimizing ten benchmark functions showed the promising results and thus this method should be investigated further.
Keywords: resource definition framework, SPARQL, best solutions, RDF, PSO
Published: 15.06.2017; Views: 405; Downloads: 244
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Regulation of irregular neuronal firing by autaptic transmissionDaqing Guo
, Shengdun Wu
, Mingming Chen
, Matjaž Perc
, Yangsong Zhang
, Jingling Ma
, Yan Cui
, Peng Xu
, Yang Xia
, Dezhong Yao
, 2016, original scientific article
Abstract: The importance of self-feedback autaptic transmission in modulating spike-time irregularity is still poorly understood. By using a biophysical model that incorporates autaptic coupling, we here show that self-innervation of neurons participates in the modulation of irregular neuronal firing, primarily by regulating the occurrence frequency of burst firing. In particular, we find that both excitatory and electrical autapses increase the occurrence of burst firing, thus reducing neuronal firing regularity. In contrast, inhibitory autapses suppress burst firing and therefore tend to improve the regularity of neuronal firing. Importantly, we show that these findings are independent of the firing properties of individual neurons, and as such can be observed for neurons operating in different modes. Our results provide an insightful mechanistic understanding of how different types of autapses shape irregular firing at the single-neuron level, and they highlight the functional importance of autaptic self-innervation in taming and modulating neurodynamics.
Keywords: neuronal dynamics, autapse, regulation, excitation
Published: 23.06.2017; Views: 448; Downloads: 246
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