Multiscale Design of Materials

Current methods of materials development, relying mostly on experimental tests, are slow and expensive. It often takes over a decade and costs many millions of dollars to develop and certify new materials for critical applications. With evolving constraints being placed on the use of materials arising from concerns with energy and materials resource sustainability, new approaches for materials development is essential. Moreover, it is increasingly important for materials development to be integrated into overall product design and development, allowing for optimal use of materials as well as enhancing our ability to recycle and reuse. In this paper, we discuss a new program in which we link methodologies developed over the past few decades in computational materials science to a modern computational design platform (VE-Suite) to enable the multiscale design of materials. Development of such multiscale design platforms is essential for the successful implementation of integrated computational materials engineering (ICME), an emerging discipline within materials development. We will present the basic framework of our program and discuss progress to date

Service life prediction of wood treated with wax emulsions and copper amine based solutions exposed in third use class

V raziskavi smo preučevali življenjsko dobo lesa, izpostavljenega na prostem, v tretjem razredu izpostavitve, z dvoslojnim testom. V prvem delu raziskave smo naravnim razmeram izpostavili vzorce smrekovine, impregnirane z vodnimi emulzijami montana in polietilenskih voskov v kombinaciji z borovimi spojinami. V drugem delu testa pa smo testirali vzorce, zaščitene z baker-etanolaminskim pripravkom na vodni osnovi (Silvanolin) in posameznimi sestavinami tega pripravka. Za primerjavo smo izpostavili tudi nezaščitene vzorce smrekovine, macesnovine, bukovine in hrastovine. Skozi celotno obdobje izpostavitve smo spremljali klimatske podatke pod vzorci in na vremenski postaji. Rezultati kažejo, da impregnacija z emulzijami voskov in pripravki na osnovi bakra podaljšuje življenjsko dobo lesa, a je zaščita s pripravki na osnovi bakrovih spojin boljša. Odpornost lesa, zaščitenega z emulzijami voskov in baker etanolaminskimi pripravki, je odvisna od koncentracije emulzije/ raztopine in kakovosti lesa. Na podlagi spremljanja vlažnosti in temperature lesa smo ugotovili, da se v lesu ustvarjajo ustreznejše vlažnostne razmere za razvoj gliv, kot bi sklepali iz meritev temperature in vlažnosti zraka.In our research, service life of wood exposed outdoor in the third use class, determined with double layer test, was investigated. In the first part of the investigation, Norway spruce wood specimens were impregnated with montan and polyethylene water based wax emulsion in combination with boron compounds. In the second part of the research, Norway spruce wood samples were impregnated with a copper-ethanolamine (Silvanolin) water based solution and aqueous solutions of individual components. For comparison, untreated Norway spruce, larch, beech and oak wood specimens were exposed as well. During exposition time, climate data under specimens and at weather station were recorded. The results showed that impregnation with wax emulsions and copper based solutions prolongs service life of wood, but protection with copper-ethanolamine solutions is considerably better. Resistance of wood, preserved with wax emulsions and copper-ethanolamine solutions, was influencedby concentration of emulsions/solutions and wood quality. The parallel measurements of wood moisture content and wood temperature clearly showed that there were more suitable conditions in wood for development and growth of fungi than indicated by air temperature and relative air humidity measurements

Analysis of DTK 5 data development and a proposal of the database modernization

The DTK 5 (Digital topographic map 1 : 5000) data present important topographic\ud information about the Earth’s surface, which meet the accuracy and detail criterion for the\ud 1 : 5000 scale. The DTK 5 data are assured by The Surveying and Mapping Authority of the\ud Republic of Slovenia within the project »Acquisition of DTK 5 data« and maintained in the\ud DTK 5 database. The presented work describes the development of topographic data and\ud projects at the analog to digital transformation period. The key advantages of derived DTK 5\ud data structure are compared to analog version. The detailed description of contents and\ud structure of digital DTK 5 data is overviewed as well as the analysis of the existent data. The\ud acquisiton is described according to its development. The last part of my diploma thesis\ud presents my conceptual proposals for renovation of database structure that would improve\ud data management, ensure qualitative, up-to-date and accessible information. This kind of\ud approach is important since we live in the information era

Improvement of fire reaction and mould growth resistance of a new bio-based thermal insulation material

In the present paper, the performance of an innovative thermal insulation rigid board is evaluated in terms of fire behaviour and fungal resistance. The board is based on vegetal pith and a natural gum (corn pith and sodium alginate) and it is completely compostable. This new composite was developed in previous work. Here boric acid, aluminium hydroxide and ammonium polyphosphate are used as fire retardants and montan wax, acetic acid and lactic acid are used as water repellent and fungicides respectively. Interactions between these different treatments is investigated. Both flaming and smouldering combustion processes of the different formulations are evaluated by small-scale techniques which include pyrolysis microcalorimetry and thermogravimetric analysis. A medium-scale device is also designed in order to study the impact of the different additives to the smouldering kinetics. Fire behaviour tests show that good improvement is obtained, both in flaming and smouldering combustion when boric acid is added. Although smouldering is not avoided in any case, the addition of 8% of boric acid or aluminium hydroxide slows down the speed of combustion propagation. The effect of the different additives on the moisture content and mould growth at 97% RH and 27 °C is analysed. Under such severe conditions none of the additives is able to prevent mould growth, with the exception of boric acid. None or marginal mould growth was observed on samples containing 8% of boric acid although moisture content was higher than the other cases.Peer ReviewedPreprin

Teaching sustainable development in materials science and engineering

Preparing the next generation of materials scientists and engineers requires more than teaching them knowledge of material properties and behaviors. Materials science and engineering must also take into account materials sustainability in the context of society and the environment, as discussed throughout this issue. Including topics such as sustainability in a materials curriculum is not new. Issues of ethics, costs, and so on have long been an integral part of our education. Although detailed treatment of all such topics cannot be included in a general materials education curriculum, the concepts of sustainable development and the role of materials in a sustainable future can be introduced. Indeed, many materials science programs are beginning to include these topics in their curricula. This article discusses three such programs that the authors have helped design and implement in the United States, each taking a different approach to engaging students in these topics. The intention is not to provide an exhaustive overview of education in sustainable development, but rather to describe a range of strategies that are currently being applied and to raise pertinent issues in materials science education

Minimal fungicidal and fungistatic concentrations of boron compounds for wood remediation

V raziskavi smo določili minimalno fungicidno mejno vrednost borove kisline inbakrovega sulfata pentahidrata za tri glive rjave (Gloeophyllum trabeum, Serpula lacrymans in Antrodia vaillantii) in tri glive bele trohnobe (Trametesversicolor, Pleurotus ostreatus in Hypoxylon fragiforme). Kurativno učinkovitost smo določali tako, da smo okužene smrekove in bukove lesne vzorce za 10 min potopili v vodno raztopino bakrovih oziroma borovih učinkovin. Zatem smo jih postavili na sterilno hranilno gojišče in opazovali preraščnje. Rezultati kazejo, da so borove učinkovine boljsi fungicidi kot bakrove spojine. Minimalna inhibitorna koncentracija borove kisline v lesu za kurativno zaščito je približno petkrat višja od mejne inhibitorne koncentracije za preventivno zaščito.Minimal remedial fungicidal concentrations of boric acid and copper sulphate pentahydrate for three brown (Gloeophyllum trabeum, Serpula lacrymans and Antrodia vaillantii) and three white rot (Trametes versicolor, Pleurotus ostreatus and Hypoxylon fragiforme) fungi were determined. Remedial efficacy was determined on infested spruce and beech wood specimens, which were immersed into selected copper- or boron-based preservative solutions for ten minutes. The treated specimens were transferred to nutrient medium and fungal growth was monitored. The results showed that boron compounds where better fungicides than the copper ones. Furthermore, minimal remedial boron fungicidal concentration is approximately five times higher, than the preventive minimal inhibitory concentration

Influence of PVA emulsion on leaching of boron and copper from wood and efficacy on wood decay fungi

Borove spojine učinkovito delujejo proti glivam razkrojevalkam, a se na žalost v vlažnem okolju izpirajo iz lesa. Z namenom doseči čim boljšo vezavo v les, smo borovo kislino, boraks in bakrov(II) sulfat pentahidrat kombinirali s polivinil acetatno (PVA) emulzijo. Z izbranimi pripravki smo impregnirali vzorce smreke (Picea abies) in jih izpostavili trem različnim glivam razkrojevalkam lesa (Antrodia vaillantii, Gloeophyllum trabeum in Trametes versicolor) po postopku mini blok. Del impregniranih vzorcev smo izpirali v skladu s standardom SIST EN 1250-2. Ugotovili smo, da dodatek PVA-emulzije rahlo izboljša vezavo borovih in bakrovih ionov v les. Smrekovina, impregnirana s pripravki z najnižjo koncentracijo borovih učinkovin (cB = 0,1 %), je odporna na vse testne glive, medtem ko je les, zaščiten z raztopinami na osnovi bakra, dobro zaščiten pred glivama Gloeophyllum trabeum in Trametes versicolor in neustrezno zaščiten pred glivo Antrodia vaillantii. Dodatek emulzije PVA že sam po sebi nekoliko zavre delovanje gliv in izboljša delovanje bakrovih in borovih učinkovin.Boron compounds are very effective fungicides, but they leach from wood in wet environments, unfortunately. In order to improve boron fixation, boric acid, borax and copper(II) sulphate were combined with polyvinyl acetate emulsion (PVA). Selected preservative solutions were chosen for impregnation of Norway spruce wood specimens (Picea abies). Wood blocks were exposed to three wood decay fungi Antrodia vaillantii, Gloeophyllum trabeum and Trametes versicolor according to the mini block procedure. Part of impregnated specimens was leached according to the EN 1250-2 procedure. The results showed that addition of PVA emulsion slightly improves copper and boron fixation. Spruce wood impregnated with the lowest concentration of boron based solutions (cB = 0.1%) was found resistant against tested fungi. In contrast, wood blocks impregnated with copper were sufficiently protected against G. trabeum and T. versicolor but not against A. vaillantii. Furthermore, PVA itself has a negative impact on fungal growth, and it improves performance of boron and copper based aqueous solutions

Comparison of standard procedures for estimation of biocides leaching from impregnated wood

Izpiranje aktivnih učinkovin iz impregniranega lesa je eden izmed najpomembnejših kriterijev za presojanje uporabnosti zaščitnih pripravkov za zaščito lesa na prostem. V te namene uporabljamo več različnih standardnih in nestandardnih postopkov: SIST EN 84, SIST EN V 1250-2 in priporočilo OEC D. V sklopu te raziskave smo med seboj primerjali izpiranje bakrovih in borovih spojin iz lesa, zaščitenega s pripravki: (a) vodno raztopino bakrovega sulfata, (b) bakeretanolaminskim komercialnim pripravkom Silvanolin, (c) vodno raztopino borove kisline in (d) kombinacijo borove kisline in vodne emulzije voska montana. Globinsko impregnirane vzorce smo izpirali in določili delež izpranega Cu in B. Največji delež biocidov smo izprali iz lesa zmetodo SIST EN 84, najmanj pa z metodo OEC D. Kakorkoli, z vsemi testiranimi metodami smo prišli do istega vrstnega reda pripravkov glede na delež izpranih aktivnih učinkovin iz lesa.Leaching of active ingredients from impregnated wood is one of the most frequently applied criteria for assessing the suitability of impregnated wood to be used in outdoor applications. For this purposes, several standard and nonstandard procedures are applied. Within the framework of this research, leaching of copper and boron compounds from wood, impregnated with four different wood preservatives, were compared: (a) aqueous solution of copper sulphate, (b) commercial copper-ethanolamine based solution Silvanolin, (c) aqueous solution of boric acid and, (d) combination of boric acid and montanic wax emulsion. Pressure impregnated specimens were afterwards leached according to the three different standards: SIST EN 84, SIST EN 1250 and OECD recommendation. The highest portion of leached biocides were determined according to the SIST EN 84 procedure, the lowest portion according to OECD recommendation. All three methods applied, however give us the same ranking of wood preservatives regarding the amount of emitted active ingredients