1. Defining a sustainable supply chain for buildings Off-Site envelope thermal insulation solutions : proposal of a methodology to investigate opportunities based on a context analysisMiriam Benedetti, Carlos Herce, Matteo Sforzini, Tiziana Susca, Claudia Toro, 2024, review article Abstract: External wall thermal insulation is one of the most effective solutions on the market to increase energy efficiency in the built environment. Off-Site Construction (OSC), through better control of the various parameters involved, can bring important advantages, such as the reduction of construction time, the improvement of product and process quality, etc. In the last years, the rapidly growing demand for thermal insulation systems, stimulated also by tax incentives, has generated a unique situation in Italy compared to the rest of Europe, also leading to a considerable fragmentation of the supply chain with several players involved (component and system manufacturers, distributors, and installers). The complexity of such context makes Italy an extremely challenging and insightful case study for a supply chain and sustainability study, also considering the fact that the energy efficiency of the Italian building stock represents a crucial challenge to achieve the country's energy saving goals since 40% of final energy consumption derives from buildings and 75% of the building stock presents a low energy performance (energy labels E, F and G). This article presents both an analysis of the Italian market of manufacturers of building envelope thermal insulation solutions, highlighting the different players in the supply chain in terms of number, type, and marketed products and solutions, and a focus on sustainable and recycled materials. The study also aims to define a methodology to investigate the state of play and opportunities for industrialisation of this market and its bottlenecks. In the article, a questionnaire is proposed to collect information and opinions on the spread of OSC and the perception of companies and professionals regarding the advantages and disadvantages of industrializing the sector. A first validation of the survey is presented in the form of industrial focus groups. Keywords: supply chain sustainability, industrial energy efficiency, off-site construction, construction industrialisation, sustainable building materials, modular buildings Published in DKUM: 01.10.2024; Views: 0; Downloads: 0 Link to file This document has many files! More... |
2. Investigating the influence of reflective materials on indoor thermal environment and solar reflectance in buildingsJihui Yuan, Yasuhiro Shimazaki, Masaki Tajima, Shaoyu Sheng, Zhichao Jiao, Marko Bizjak, 2024, original scientific article Abstract: This in-depth study explores the intricate dynamics of reflective materials, emphasizing their impact on the indoor thermal environment and urban heat island (UHI) mitigation. Examining diffuse highly reflective (DHR), general reflective (GR), and retro-reflective (RR) materials on a simplified building model during summer days, the research utilizes outdoor experiments to analyze air and surface temperatures, as well as solar radiation. Prioritizing key metrics—mean radiant temperature (MRT), operative temperature (OT), and solar reflectance (ρ)—the study uncovers nuanced distinctions in DHR, GR, and RR materials. Solar reflectance calculations consistently show higher values for DHR and RR materials compared to GR material, highlighting reflectance's pivotal role in influencing surface temperatures and indoor thermal environment. When evaluating the impact of exterior wall materials on building temperatures, RR material with a 76% reflectance performs similarly to DHR material (82%). Notably, with a 6% lower reflectance in RR, the temperature contrast between external and internal walls is only about 1.5 °C at its maximum, underscoring RR's effectiveness as an outer wall material for UHI mitigation and building energy conservation, surpassing both DHR and GR materials. Keywords: urban heat island, reflective materials, indoor thermal environment, solar reflectance, simplified building model Published in DKUM: 23.08.2024; Views: 110; Downloads: 6 Full text (4,82 MB) |
3. Exploring an infrastructure investment methodology to risk mitigation from rail hazardous materials shipmentsAli Vaezi, Manish Verma, 2021, original scientific article Abstract: Railroad is one of the primary modes to transport hazardous materials (hazmat) in North America. For instance, Canadian railroads carried around 50 million tons of hazmat in 2018. Given the inherent danger of trains carrying hazmat, this study aimed at exploring a novel way towards mitigation of the associated risk. This study sought to investigate whether proper rail track infrastructure investment can mitigate the risk from hazmat shipments. To this end, a methodology was developed and then applied to the Canadian railroad network. The proposed three-step methodology captured the differing perspectives of rail carriers and regulatory agencies, and entailed (1) ascertaining the risk-level of various yards and links in the given railroad network, (2) specifying potential candidates for infrastructure investment, and (3) finding the optimum set of investment decisions. The proposed methodology was then applied to the Canadian railroad network to demonstrate that significant risk-reduction can beachieved by adding alternative rail-links around the riskiest locations (i.e. the network hot-spots), and also to show that risk-reduction function is non-linear with non-monotonous behavior. The study showed the possibility of significant hazmat risk reduction through alternative rail-links that could take traffic away from the network hot-spots. The methodology and the resultsfrom the Canadian case can be used by railroad companies and policy makers to estimate the value of potentially risk-reducinginfrastructure investments. Keywords: risk mitigation, railroad network, hazardous materials, infrastructure investment, optimization, transportation safety Published in DKUM: 23.08.2024; Views: 61; Downloads: 7 Full text (1,85 MB) This document has many files! More... |
4. 20th European Meeting on Supercritical Fluids : Book of Abstracts2024 Abstract: The 20th European Meeting on Supercritical Fluids (EMSF 2024) was hosted by the Faculty of Chemistry and Chemical Engineering of the University of Maribor from 26 May to 29 May 2024 in Maribor, Slovenia. The EMSF 2024 was a joint event of the International Society for the Advancement of Supercritical Fluids (ISASF) and the European Federation of Chemical Engineering (EFCE) Working Party on High Pressure Technology (WP HPT) Event No. 807. This symposium provided an excellent opportunity for engineers, chemists, physicists, food technologists, and biologists to meet and discuss new ideas, review ongoing challenges, present potential solutions, and identify future issues related to high pressure technologies and supercritical fluids. The aim of the meeting was to deepen connections between researchers, establish new contacts, and promote synergies and partnerships between researchers. The symposium presented the latest advances in high-pressure process technologies that can contribute to the further development of the field. Keywords: supercritical fluids, fundamental data, novel materials, industrial applications, research and development Published in DKUM: 24.07.2024; Views: 161; Downloads: 22 Full text (12,44 MB) This document has many files! More... |
5. Economic viability of alternative bedding material in broiler chicken farmingJernej Prišenk, Maksimiljan Brus, 2022, original scientific article Abstract: The aim of this paper is to assess the economic viability of two different bedding materials used in broiler chicken farming processes. The materials considered are wood shavings and slice-dedusted straw. The slice-dedusted straw is considered an alternative type of bedding material produced by a company from Slovenia. While the technological and economic assessment of this type of bedding material has already been researched in the case of horse breeding, it is something new in the case of broiler chicken farming. Data collection is structured from two trials. Trial one (T1) is also known as daily observations, and trial two (T2) involves obtaining input data at the end of the fattening period. During T1, daily observations are focused on collecting data from technical characteristics, and in T2, the percentage of death proportions and average increments are observed, calculated, and considered as economic input data. The cost calculation model is used for the calculation of several different technical-economic indicators, which denote the influence of different bedding materials no economic production viability. Favorable economic results were found for slice-dedusted straw, which shows that this kind of alternative bedding material could be the better option. Keywords: bedding materials, feasibility analysis, broiler chicken, cost calculation model Published in DKUM: 02.07.2024; Views: 111; Downloads: 11 Full text (6,19 MB) This document has many files! More... |
6. Materials for HybridNeuro webinar titled "Validation of results: statistical models and MU identification accuracy"Aleš Holobar, Nina Murks, 2024, complete scientific database of research data Abstract: This dataset contains a collection of teaching materials that were used in the HybridNeuro project webinar titled "Validation of results: statistical models and MU identification accuracy". The webinar was presented by Aleš Holobar and covered the complexities of motor unit (MU) identification accuracy, regression analysis and Bayesian models. The primary aim of the webinar was to spark a robust discussion within the scientific community, particularly focusing on the application and implications of linear mixed models and Bayesian regression in the realm of MU identification. The teaching materials include Matlab and R source code for statistical analysis of the included data, as well as three examples of MU identification results in CSV format (from both synthetic and experimental HDEMG signals). The presentation slides in PDF format are also included. The dataset is approximately 9 MB in size. Keywords: HybridNeuro, webinar, teaching materials, statistical models, regression analysis, motor unit identification, matlab, rstudio, statistics, surface high density electromyogram (HDEMG), tibialis anterior, dataset Published in DKUM: 30.05.2024; Views: 221; Downloads: 15 Full text (108,35 KB) This document has many files! More... |
7. Thermo-mechanical behavior and strain rate sensitivity of 3D-printed polylactic acid (PLA) below glass transition temperature (Tg)Vukašin Slavković, Blaž Hanželič, Vasja Plesec, Strahinja Milenković, Gregor Harih, 2024, original scientific article Abstract: This study investigated the thermomechanical behavior of 4D-printed polylactic acid (PLA), focusing on its response to varying temperatures and strain rates in a wide range below the glass transition temperature (Tg). The material was characterized using tension, compression, and dynamic mechanical thermal analysis (DMTA), confirming PLA’s strong dependency on strain rate and temperature. The glass transition temperature of 4D-printed PLA was determined to be 65 °C using a thermal analysis (DMTA). The elastic modulus changed from 1045.7 MPa in the glassy phase to 1.2 MPa in the rubber phase, showing the great shape memory potential of 4D-printed PLA. The filament tension tests revealed that the material’s yield stress strongly depended on the strain rate at room temperature, with values ranging from 56 MPa to 43 MPA as the strain rate decreased. Using a commercial FDM Ultimaker printer, cylindrical compression samples were 3D-printed and then characterized under thermo-mechanical conditions. Thermo-mechanical compression tests were conducted at strain rates ranging from 0.0001 s−1 to 0.1 s−1 and at temperatures below the glass transition temperature (Tg) at 25, 37, and 50 °C. The conducted experimental tests showed that the material had distinct yield stress, strain softening, and strain hardening at very large deformations. Clear strain rate dependence was observed, particularly at quasi-static rates, with the temperature and strain rate significantly influencing PLA’s mechanical properties, including yield stress. Yield stress values varied from 110 MPa at room temperature with a strain rate of 0.1 s−1 to 42 MPa at 50 °C with a strain rate of 0.0001 s−1. This study also included thermo-mechanical adiabatic tests, which revealed that higher strain rates of 0.01 s−1 and 0.1 s−1 led to self-heating due to non-dissipated generated heat. This internal heating caused additional softening at higher strain rates and lower stress values. Thermal imaging revealed temperature increases of 15 °C and 18 °C for strain rates of 0.01 s−1 and 0.1 s−1, respectively. Keywords: smart materials, shape memory polymer, 3D printing, 4D printing, thermo-mechanical experiments Published in DKUM: 29.05.2024; Views: 248; Downloads: 13 Full text (5,88 MB) This document has many files! More... |
8. Mechanical behaviour of photopolymer cell-size graded triply periodic minimal surface structures at different deformation ratesYunus Emre Yilmaz, Nejc Novak, Oraib Al-Ketan, Hacer Irem Erten, Ulas Yaman, Anja Mauko, Matej Borovinšek, Miran Ulbin, Matej Vesenjak, Zoran Ren, 2024, original scientific article Abstract: This study investigates how varying cell size affects the mechanical behaviour of photopolymer Triply Periodic Minimal Surfaces (TPMS) under different deformation rates. Diamond, Gyroid, and Primitive TPMS structures with spatially graded cell sizes were tested. Quasi-static experiments measured boundary forces, representing material behaviour, inertia, and deformation mechanisms. Separate studies explored the base material’s behaviour and its response to strain rate, revealing a strength increase with rising strain rate. Ten compression tests identified a critical strain rate of 0.7 s−1 for “Grey Pro” material, indicating a shift in failure susceptibility. X-ray tomography, camera recording, and image correlation techniques observed cell connectivity and non-uniform deformation in TPMS structures. Regions exceeding the critical rate fractured earlier. In Primitive structures, stiffness differences caused collapse after densification of smaller cells at lower rates. The study found increasing collapse initiation stress, plateau stress, densification strain, and specific energy absorption with higher deformation rates below the critical rate for all TPMS structures. However, cell-size graded Primitive structures showed a significant reduction in plateau and specific energy absorption at a 500 mm/min rate. Keywords: cellular materials, triply periodical minimal surface, photopolymer, mechanical properties, strain rate, experimental compressive testing, computer simulations Published in DKUM: 22.05.2024; Views: 216; Downloads: 15 Full text (9,33 MB) This document has many files! More... |
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10. Advance analysis of the obtained recycled materials from used disposable surgical masksAlen Erjavec, Julija Volmajer Valh, Silvo Hribernik, Tjaša Kraševac Glaser, Lidija Fras Zemljič, Tomaž Vuherer, Branko Neral, Mihael Brunčko, 2024, original scientific article Abstract: The production of personal protective equipment (PPE) has increased dramatically in recent years, not only because of the pandemic, but also because of stricter legislation in the field of Employee Protection. The increasing use of PPE, including disposable surgical masks (DSMs), is putting additional pressure on waste collectors. For this reason, it is necessary to find high-quality solutions for this type of waste. Mechanical recycling is still the most common type of recycling, but the recyclates are often classified as low-grade materials. For this reason, a detailed analysis of the recyclates is necessary. These data will help us to improve the properties and find the right end application that will increase the value of the materials. This work represents an extended analysis of the recyclates obtained from DSMs, manufactured from different polymers. Using surface and morphology tests, we have gained insights into the distribution of different polymers in polymer blends and their effects on mechanical and surface properties. It was found that the addition of ear loop material to the PP melt makes the material tougher. In the polymer blends obtained, PP and PA 6 form the surface (affects surface properties), while PU and PET are distributed mainly inside the injection-molded samples. Keywords: mechanical recycling, disposable surgical mask, morphology, surface properties, mechanical properties, nonwoven materials, PPE Published in DKUM: 09.04.2024; Views: 232; Downloads: 11 Full text (8,08 MB) This document has many files! More... |