Composite materials based on nanotubes and metal matrix

Ugljične nanocijevi su izuzetan materijal zbog svoje čvrstoće i veoma male težine te se zbog toga koriste za dobivanje kompozita sa metalnom matricom pri čemu uvelike poboljšavaju svojstva nastalog materijala u odnosu na svojstva matrice. Metalu dodane ugljične nanocijevi mu poboljšavaju mehanička svojstva, a da pri tome ne utječe na težinu materijala. Iako su cijevi poznate čovječanstvu već duže vremena još uvijek se razvijaju tehnologije kojima bi se moglo lakše i kvalitetnije pripraviti novi kompozitni materijal na nanoskali. U ovom radu dan je osvrt na ugljične nanocijevi, nanotehnologiju, kompozitne materijale i njihovu pripremu te na kompozitne materijale s metalnom matricom ojačane ugljičnim nanocijevima. Prikazane su prednosti kompozitnih materijala s metalnom matricom i ugljičnim nanocijevima te što možemo u budućnosti očekivati od ovog materijala.Carbon nanotubes are exceptional material due to their strength and very low weight and therefore can be used in preparation of a metal matrix composite, which greatly improves the properties of the material produced in relation to the matrix properties. The carbon nanotube added to the metal improve mechanical properies without affecting the weight of the material. Although nanotubes are known to mankind for a long time, technologies are still being developed to manage the preparation of new nanoscale composite materials. This paper gives an overview of carbon nanotubes, nanotechnology, composite materials and their preparation, and on composite materials with metal matrices reinforced with carbon nanotubes. The advantages of composite materials with metal matrices and carbon nanotubes are shown and expectations for those materials in the future are given

Machine Learning - The Application for Demonstration of Main Approaches

Tato práce se zabývá především základními algoritmy strojového učení. V první části práce jsou vybrané algoritmy popsány. Zbývající část se následně věnuje implementaci těchto algoritmů a vytvoření demonstračních úloh pro každý z nich.This work mainly deals with the basic machine learning algorithms. In the first part, the selected algorithms are described. The remaining part is then devoted to the implementation of these algorithms and a demonstration of tasks for each of them.

Prezentation of characters with disabilities in children's books

Literatura, točnije pisana riječ, od samog je početka prisutna u životu pojedinca te mu služi kao posrednik u primanju informacija i stjecanju novih znanja, budući da je njome moguće na indirektan način upoznati svijet koji nas okružuje i različitosti unutar njega. Posebice je posrednički značaj literature vidljiv tijekom odrastanja, obzirom da djeca i mladi nemaju priliku doći u doticaj sa svim fenomenima prisutnim u ovome svijetu, razumjeti njihove karakteristike te pritom steći određeno iskustvo i formirati vlastite stavove. Jedan od takvih fenomena su nedvojbeno teškoće i invaliditet, obzirom da su prisutne kod određenog postotka populacije. Stoga se otvara pitanje postoje li literarna djela koja mogu poslužiti kao posrednik u širenju svjesnosti o problematici teškoća i invaliditeta kod djece i mladih. Cilj rada je dobiti uvid u dostupna literarna djela na hrvatskom jeziku koja u svome sadržaju obrađuju tematiku teškoća i invaliditeta, analizirati ih s literarnog i edukacijskog aspekta kako bi se time utvrdila njihova kvaliteta i razina primjerenosti prilikom korištenja u radu s djecom i mladima u svrhu njihove senzibilizacije spram pojedinaca s teškoćama i invaliditetom. Prikupljeni podaci ukazuju kako postoji određen, nešto manji, broj literarnih djela na hrvatskom jeziku koja se ističu svojom kvalitetom, točnije na prikladan način progovaraju o problematici teškoća odnosno invaliditeta te su time primjerena za korištenje u radu s djecom i mladima. No, generalno, sama književnost i dalje nije potpuno očišćena od diskriminativnih prikaza osoba s teškoćama i invaliditetom, što vodi do potrebe za kreiranjem sustavnog pregleda u kojem će se posebno istaknuti prikladna literarna djela kako bi djeca i mladi, ali i njihovi roditelji te obrazovni stručnjaci, bili u mogućnosti učiniti ispravan odabir tijekom vlastite potrage za prikladnim literarnim djelima koja u svom sadržaju obrađuju tematiku teškoća i invaliditeta.Literature, or rather a written word, has been present in the life of the individual since its beginning and serves as a mediator in receiving information and acquiring new knowledge, since it is, with literature, indirectly possible to get to know the world that surrounds us and the differences within it. The importance of literature is particularly evident during growing up, as children and young adults do not have the opportunity to be in touch with all the phenomena present in this world, to understand their characteristics and to gain some experience in addition to form their own attitudes. Undoubtedly, one such phenomenon is disability, considering that it is present at a certain percentage of the population. Therefore, the question arises as to whether there are any books that can serve as a mediator with children and young adults in the dissemination of their awareness of various disabilities. Aim of this paper is to get insight into available books in Croatian language about disability, to analyze them from literary and educational aspect to determine their quality and level of its appropriateness in order of using them with children and young adults in purpose of their sensibilitation towards individuals with disabilities. The collected data indicate that there is a certain, smaller, number of books in Croatian language which stand out with its quality, in fact they adequately discuss issues of disabilities and are consequently appropriate for education of children and young adults. But, generally, literature itself is still not completely cleaned from the discriminatory portrayals of people with disabilities, leading to the necessity of creating a systematic review in which appropriate books will be particularly highlighted, so that children and young adults, as well as their parents and educators, will be able to make right choice during their own search for suitable books that are promoting disabilities in its content

Composite materials based on nanotubes and metal matrix

Ugljične nanocijevi su izuzetan materijal zbog svoje čvrstoće i veoma male težine te se zbog toga koriste za dobivanje kompozita sa metalnom matricom pri čemu uvelike poboljšavaju svojstva nastalog materijala u odnosu na svojstva matrice. Metalu dodane ugljične nanocijevi mu poboljšavaju mehanička svojstva, a da pri tome ne utječe na težinu materijala. Iako su cijevi poznate čovječanstvu već duže vremena još uvijek se razvijaju tehnologije kojima bi se moglo lakše i kvalitetnije pripraviti novi kompozitni materijal na nanoskali. U ovom radu dan je osvrt na ugljične nanocijevi, nanotehnologiju, kompozitne materijale i njihovu pripremu te na kompozitne materijale s metalnom matricom ojačane ugljičnim nanocijevima. Prikazane su prednosti kompozitnih materijala s metalnom matricom i ugljičnim nanocijevima te što možemo u budućnosti očekivati od ovog materijala.Carbon nanotubes are exceptional material due to their strength and very low weight and therefore can be used in preparation of a metal matrix composite, which greatly improves the properties of the material produced in relation to the matrix properties. The carbon nanotube added to the metal improve mechanical properies without affecting the weight of the material. Although nanotubes are known to mankind for a long time, technologies are still being developed to manage the preparation of new nanoscale composite materials. This paper gives an overview of carbon nanotubes, nanotechnology, composite materials and their preparation, and on composite materials with metal matrices reinforced with carbon nanotubes. The advantages of composite materials with metal matrices and carbon nanotubes are shown and expectations for those materials in the future are given

Quality of Life 10 Years after Sleeve Gastrectomy: A Multicenter Study

Objective: Sleeve gastrectomy (SG) has recently become the most commonly applied bariatric procedure worldwide. Substantial regaining of weight or severe reflux might compromise quality of life (QOL) after SG in the long-term follow-up. Long-term data on patients’ QOL is limited, even though the persistent improvement in QOL is one of the aims of bariatric surgery. The objective of this study was to present patients’ QOL 10 years after SG. Methods: Of 65 SG patients with a follow-up of ≥10 years after SG who were asked to fill out the Bariatric Quality of Life Index (BQL) and Short Form 36 (SF36) questionnaires, 48 (74%) completed them. This multicenter study was performed in a university hospital setting in Austria. Results: The BQL score revealed nonsignificant differences between the patients with > 50% or < 50% excess weight loss (EWL). It did show significant differences between patients with and without any symptoms of reflux. Patients with < 50% EWL scored significantly lower in 3/8 categories of SF36. Patients suffering from reflux had significantly lower scores in all categories. Conclusions: EWL and symptomatic reflux impair patients’ long-term QOL after SG

Biodegradation of materials base on thermoplastic strach by composting process

Prekomjerna uporaba polimernih ambalažnih materijala dovela je do prevelike zasićenosti planeta ambalažnim otpadom te velike potrebe za pronalaskom zamjenskog biorazgradivog polimernog materijala koji bi mogao zadovoljiti potrošačku kao i ekološku svrhu. Upravo u ovom radom ispitana je mogućnost biorazgradnje polimernih mješavina polietilena niske gustoće (PE-LD) i termoplastičnog škroba (TPS) procesom kompostiranja. Tijekom procesa kompostiranja praćeni su fizikalno kemijski parametri značajni za samu provedbu procesa kompostiranja, kao i mikrobiološka analiza kompostne mase. Proces kompostiranja proveden je u adijabatskom reaktoru na laboratorijskoj razini tijekom 16 dana. Provedena je optimizacija procesa kompostiranja primjenom kinetičkog modela prvog reda važna za dizajniranje i rad postrojenja za kompostiranje. Biorazgradnja polimernih PE-LD/TPS mješavina pratila se gubitkom mase kao i promatranjem promjena morfološke strukture svjetlosnim i pretražnim elektronskim mikroskopom prije i nakon procesa kompostiranja. Dodatak TPS-a polietilenu niske gustoće utjecao je i potaknuo biorazgradnju polimernih PE-LD/TPS mješavina. Veći udio TPS-a omogućio je veći gubitak mase, odnosno bržu razgradnju. TPS pogoduje biorazgradnji polimernih PE-LD/TPS mješavina zbog naglašene amorfne strukture kao i hidrofilnog karaktera TPS-a, te je i dobar izvor hrane mikroorganizmima koji su upravo odgovorni za biorazgradnju polimernih mješavina tijekom procesa kompostiranja.Excessive use of polymeric packaging materials has led to an oversaturation of the planet with packaging waste and a great need to find a replacement biodegradable polymeric material that could meet consumer as well as environmental purposes. This paper investigates the possibility of biodegradation of polymer blends of low density polyethylene (PE-LD) and thermoplastic starch (TPS) by composting. During the composting process, physicochemical parameters important for the implementation of the composting process were monitored, as well as microbiological analysis of the compost mass. The composting process was carried out in an adiabatic reactor at the laboratory level for 16 days. The optimization of the composting process was carried out using a first-order kinetic model important for the design and operation of the composting plant. Biodegradation of polymer PE-LD/TPS blends was monitored by weight loss as well as by observing changes in morphological structure with a light and scanning electron microscope before and after the composting process. The addition of TPS to low density polyethylene affected and promoted the biodegradation of polymer PE-LD/TPS blends. A higher share of TPS enabled higher mass loss, i.e. faster decomposition. TPS favors the biodegradation of polymer PE-LD/TPS blends due to the pronounced amorphous structure and hydrophilic character of TPS. It is a good source of food for microorganisms that are responsible for their biodegradation during the composting process