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Abstract: V prispevku so predstavljene obsežne eksperimentalne raziskave obnašanja večetažnih zidanih strižnih sten z odprtinami pri potresni obtežbi. Preiskali smo odziv 3-etažnega preizkušanca v naravnem merilu na potresno obtežbo, s katero smo preučevali odziv tipične 5-etažne zidane stavbe, grajene na območju Slovenije in njene širše okolice v času pred letom 1964 (pred prvimi potresni predpisi). Vzporedno smo opravili osem cikličnih strižnih preiskav posameznih zidov pri štirih tipih robnih pogojev. Z analizo rezultatov obsežnih meritev sil in deformacij na površini večetažnih strižnih sten smo ovrednotili vpliv vertikalnih in horizontalnih elementov strižne stene na posamezni slop ter iskali najustreznejši tip robnih pogojev za simulacijo potresnega odziva v preiskavi posameznega zidnega slopa.
Keywords: nearmirano zidovje, ciklične strižne preiskave, opečni votlak, preiskava v naravnem merilu, optični sistem za merjenje deformacij
Published in DiRROS: 05.09.2023; Views: 362; Downloads: 132
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Abstract: We present a novel % cutoff concept of colorimetric indication of relative humidity based on dye dissolution in condensed water in capillaries of selectively functionalized mesoporours host SiO2 material. Consistently high levels of indoor air humidity induces mold and algae growth which represent a potential risks for human health and have deteriorating effect on walls as well. Simple localized humidity detection of high humidity with naked eye especially at places with low air circulation, where growth of mold usually starts first, is therefore highly desirable. The reporting dye was integrated in the non-functionalized mesoporous silica matrix with different pore diameters and selective-functionalized mesoporous silica material. After exposure to the environment of different air humidities the dye dissolved in water causing color change of adsorbent. With the use of adsorbents with different mesopore diameters high ability to tune the value of relative humidity when complete capillary condensation occurred was achieved. Materials with pore diameters of 3.0%nm, 3.5%nm and 7.0%nm exhibit gradual color change when reaching relative humidity up to 55, 79 and 88 RH% respectively. After selective methylation of the material with 7.0%nm pore diameter, non-gradual cutoff color change was achieved. Sample exhibited color change at narrow range of relative humidity (cutoff color change). Due to selective functionalized outer surface the dye dissolution occur only in condensed water in pores and therefore provide colorimetric indication only in this range. Selectively modified silica material has a great potential for a straightforward detection of high humid environment.
Keywords: turn-on colorimetric probe, selective functionalization, mesoporous silica, relative humidity, capillary condensation
Published in DiRROS: 05.09.2023; Views: 403; Downloads: 285
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Keywords: varstvo gozdov, morfološke analize, Dothistroma, rjavenje borovih iglic, Lecanosticta acicola, rdeča pegavost borovih iglic, bori, Pinus
Published in DiRROS: 16.08.2023; Views: 355; Downloads: 0

Abstract: The ISO 5660-1 cone calorimeter is an affordable, practical, and commonly used solution for the measurement of main fire properties of products and materials. Among its chief drawbacks is its limited ability to reproduce combustion conditions found in real fires. This deficiency is mainly due to its inability to control oxygen availability in order to simulate an underventilated fire. As several toxic or potentially toxic species are formed primarily in oxygen-poor conditions, the controlled atmosphere cone calorimeter (CACC), now defined in ISO 5660-5, is a major improvement when trying to study the toxicity of fire effluents. A proposed additional modification of the CACC via the introduction of chimney sampling ports and oxygen sensors improves the reproducibility and veracity of effluent sampling. This approach allows the implementation of various techniques to sample, collect, and analyze the generated fire effluents. In this study, the experimental set-up was used to capture fire effluents generated by burning wood under different ventilation conditions. A gas chromatograph coupled with mass spectrometer was used to assess and compare the chemical composition of the collected samples. The results obtained with the new experimental set-up proved the ability of the system to reproducibly generate fire effluents under various controlled burning circumstances. It could prove useful as a tool in characterizing the toxicity of fire effluents from various materials on a benchtop scale and ultimately contribute data for the numerical modeling of toxicity of fire effluents in real buildings.
Keywords: modified cone calorimeter, controlled atmosphere, wood, fire effluents, open access
Published in DiRROS: 14.07.2023; Views: 450; Downloads: 339
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Keywords: medicinska fizika, medicinsko slikanje, hiperspektralno slikanje, tumorji, zdravljenje
Published in DiRROS: 16.06.2023; Views: 479; Downloads: 111
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