1401. An experimental apparatus for bench-scale fire testing using electrical heating padsAleksandra Seweryn, Andrea Lucherini, Jean-Marc Franssen, 2024, original scientific article Abstract: This research study concerns an experimental, budget-friendly, electricity- powered apparatus for bench-scale fire testing. The apparatus consists of various elements, of which the most important are ceramic heating pads, used to impose heat fluxes on exposed surfaces of specimens. The test method allows to control the heating pads’ temperature and to adjust the distance between the heating pads and the specimen to obtain well-defined heat fluxes up to 50–60 kW/m2. Higher heat fluxes and temperatures can be obtained by setting the heating pads in full power mode, with or without the use of a thermal shield, which can lead to heat fluxes up to 150 kW/m2. The heating and thermal boundary conditions imposed by the apparatus are characterised and discussed, and the thickness of the convective boundary layer at the heating pads’ surface is estimated significantly lower than in the case of gas- fired radiant panels. The performance of the apparatus is analysed for various conditions: controlling the temperature of the heating pads, in an open environment or with the presence of thermal shields, and in full power mode. A few examples of application of the apparatus to fire test typical construction materials (steel and glass) are also presented. These results emphasise the well-defined heating conditions in temperature-controlled mode. The study finally discusses the advantages and limitations of the apparatus, as well as many possibilities of future applications and improvement for future research studies. Keywords: radiant panels, fire testing, heat transfer, heat flux, electrical heating pads, thermal boundary conditions Published in DiRROS: 15.04.2024; Views: 310; Downloads: 754
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1402. Influence of test methodology on the characterization of the parallel-to-grain timber embedment strength and foundation modulus of dowelsCaroline D. Aquino, Rodrigues Leonardo G., Michael Schweigler, Meta Kržan, Zheng Li, Jorge M. Branco, 2024, original scientific article Abstract: A reliable determination of the embedment strength and foundation modulus of timber elements is critical for the design and safety assessment of joints in timber structures. However, the existence of various test configurations for characterising the embedding properties of large diameter steel fasteners in timber elements poses challenges in directly comparing and utilising available test data. This paper aims to provide an insight into the influence of embedment property test methods, comparing experimental results from different test setups within the guidelines of the EN 383 and ASTM D 5764-97a standards for European softwood species, Scots pine wood (Pinus sylvestris) and Norway spruce (Picea abies). In addition to the test guidelines, the thickness of the specimen and the application of the load was evaluated within the protocols. A comprehensive statistical analysis was performed to identify statistically significant differences between the groups evaluated. The results of the analysis revealed disagreement between the standards in the evaluation of the strength of the embedding, highlighting the potential bias inserted by the experimental setup and protocol. Furthermore, it was proven that the thickness of the specimens influences both the embedding strength and the foundation modulus of the wood species tested. Finally, no distinctions were observed between tensile and compressive loading within the guidelines of the EN 383 standard. Keywords: embedment strength, foundation modulus, dowel-type connections, test methods Published in DiRROS: 15.04.2024; Views: 291; Downloads: 151
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1403. Why geopolymers and alkali-activated materials are key components of a sustainable world : a perspective contributionWaltraud M. Kriven, Cristina Leonelli, John L. Provis, Aldo R. Boccaccini, Cyril Attwell, Vilma Ducman, Claudio Ferone, Sylvie Rossignol, Tero Luukkonen, Jannie S. J. Van Deventer, José V. Emiliano, Jérôme E. Lombardi, 2024, original scientific article Abstract: This perspective article delves into the transformative potential of alkali-activated materials, acid-activated materials, and geopolymers in mitigating climate change and market challenges. To harness the benefits of these materials, a comprehensive strategy is proposed. This strategy aims to integrate these materials into existing construction regulations, facilitate certification, and promote market access. Emphasizing research and innovation, the article advocates for, increased funding to refine the chemistry and production of these materials, prioritizing low-cost alternatives and local waste materials. Collaboration between academia and industry is encouraged to expedite technological advances and broaden applications. This article also underscores the need to develop economic and business models emphasizing the long-term benefits of these materials, including lower life-cycle costs and reduced environmental impact. Incentivizing adoption through financial mechanisms like tax credits and subsidies is suggested. The strategy also includes scaling up production technology, fostering industrial collaboration for commercial viability, and developing global supply chains. Educational programs for professionals and regulators are recommended to enhance awareness and adoption. Additionally, comprehensive life-cycle assessments are proposed to demonstrate environmental benefits. The strategy culminates in expanding the applications of these materials beyond construction, fostering international collaboration for knowledge sharing, and thus positioning these materials as essential for sustainable construction and climate change mitigation. Keywords: geopolymers, alkali activated materials, perspective Published in DiRROS: 15.04.2024; Views: 336; Downloads: 376
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1404. Utilisation of reused steel and slag : analysing the circular economy benefits through three case studiesGenesis Camila Cervantes Puma, Adriana Salles, Janez Turk, Viorel Ungureanu, Luís Bragança, 2024, review article Abstract: This research explores sustainable construction practices focusing on material reuse, specifically reclaimed structural steel and slag. In general, the building stock is not designed for deconstruction, and material recovery for reuse at the end of life of buildings is complex and challenging. The study evaluates the benefits of content reuse through a thorough analysis of three case studies— BedZED eco-friendly housing, Angus Technopôle building, and the use of steel slag aggregate in road construction. It highlights the value of reclaimed structural steel and by-products like steel slag in waste reduction, energy conservation, and resource preservation. The BedZED case study showcases recycled steel’s cost-effectiveness and economic viability in construction, while the Angus Technopôle building exemplifies the adaptive reuse of an old steel frame building. Additionally, the third case study showcases the benefits of using Electric Arc Furnace C slag in asphalt-wearing courses, highlighting the reduction in greenhouse gas emissions and environmental impact. The versatility of reclaimed structural steel and slag is evident in integrating material reuse in building construction and road infrastructure. These case studies illustrate the potential for reusing steel and its by-products in various construction contexts, from eco-friendly housing to road development. Therefore, the study aims to demonstrate the feasibility and benefits of sustainable practices within the construction industry by showcasing the successful incorporation of reclaimed steel and slag in these projects. Considering the significant contributions of building construction to global greenhouse gas emissions, raw material extraction, and waste production, the study advocates for adopting circular economy (CE) principles within the construction industry. Finally, the analysis of case studies underscores the advantages of reclaimed structural steel and the valorisation of steel slag through the lens of CE and their contribution to sustainable development. Keywords: circular economy, reused steel, steel slag aggregate, reclaimed steel, steel members Published in DiRROS: 12.04.2024; Views: 311; Downloads: 148
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1405. Bioresorbability dependence on microstructure of additivelly- manufactured and conventionally-produced Fe-Mn alloysMatjaž Godec, Jakob Kraner, Danijela Anica Skobir Balantič, Irena Paulin, Damjana Drobne, Veno Kononenko, Aleksandra Kocijan, Paul J. McGuiness, Črtomir Donik, 2024, complete scientific database of research data Abstract: The dataset supports the results shown in the tables and figures in the article entitled “Bioresorbability Dependence on Microstructure of Additivelly-Manufactured and Conventionally-Produced Fe-Mn Alloys” (doi.org/10.1016/j.jmrt.2024.04.097). It contains measurements of corrosion resistance of Fe-Mn samples, phase analysis of samples A, B and C, surface and depth profiling XPS, EDS measurements of a cross-section of Fe-Mn powder particles and viability measurements results. Keywords: Fe-Mn alloy, laser powder bed fusion, bioresorbable, microstructure, corrosion behaviour, biocompatibility Published in DiRROS: 12.04.2024; Views: 438; Downloads: 292
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1406. Identification of three anatomical patterns of the spinal accessory nerve in the neck by neurophysiological mappingBoštjan Lanišnik, Miha Žargi, Zoran Rodi, 2014, original scientific article Abstract: Background. In spite of preservation of the accessory nerve there is still considerable proportion of patients with partial nerve damage during modified radical neck dissection (MRND). Methods. The nerve was identified during the surgery and its branches for the trapezius muscle mapped with nerve monitor. Results. The accessory nerve was mapped during 74 hemineck dissections and three patterns were identified. In type 1 nerve exits at the posterior end of the sternocleidomastoid muscle (SCm) and then it enters the level V (66 %). In type 2 the nerve for trapezius muscle branches off before entering the SCm (22 %). In type 3 the nerve exits at the posterior part of the SCm and it joins to the cervical plexus (12 %). The nerve than exits this junction more medially as a single trapezius branch. Conclusions. The description of three anatomical patterns in level II and V could help preserving the trapezius branch during MRND. Keywords: spinal accessory nerve, nerve mapping, neck dissection, anatomy, shoulder disability Published in DiRROS: 11.04.2024; Views: 598; Downloads: 401
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1407. Intercalated chemotherapy and erlotinib for advanced NSCLC : high proportion of complete remissions and prolonged progression-free survival among patients with EGFR activating mutationsMatjaž Zwitter, Karmen Stanič, Mirjana Rajer, Izidor Kern, Martina Vrankar, Natalija Edelbaher, Viljem Kovač, 2014, original scientific article Abstract: Background. Pharmaco-dynamic separation of cytotoxic and targeted drugs might avoid their mutual antagonistic effect in the treatment of advanced non-small cell lung cancer (NSCLC). Patients and methods. Eligible patients were treatment-naive with stage IIIB or IV NSCLC. In addition, inclusion was limited to never-smokers or light smokers or, after 2010, to patients with activating epidermal growth-factor receptor (EGFR) mutations. Treatment started with 3-weekly cycles of gemcitabine and cisplatin on days 1, 2 and 4 and erlotinib on days 5 to 15. After 4 to 6 cycles, patients continued with erlotinib maintenance. Results. Fifty-three patients were recruited into the trial: 24 prior to 2010 (of whom 9 were later found to be positive for EGFR mutations), and 29 EGFR mutation-positive patients recruited later. Unfavourable prognostic factors included stage IV disease (51 patients - 96%), performance status 2%3 (11 patients - 21%) and brain metastases (15 patients - 28%). Grade 4 toxicity included 2 cases of neutropenia and 4 thrombo-embolic events. The 15 EGFR negative patients had 33% objective response rate, median progression-free survival (PFS) 6.0 months and median survival 7.6 months. Among 38 EGFR positive patients, complete response (CR) or partial response (PR) were seen in 16 (42.1%) and 17 (44.7%) cases, respectively. PET-CT scanning was performed in 30 patients and confirmed CR and PR in 16 (53.3%) and 9 (30.0%) cases, respectively. Median PFS for EGFR mutated patients was 21.2 months and median survival was 32.5 months. Conclusions. While patients with EGFR negative tumors do not benefit from addition of erlotinib, the intercalated schedule appears most promising for those with EGFR activating mutations. Keywords: non-small cell lung cancer, EGFR activating mutations, gemicitabine, erlotinib Published in DiRROS: 11.04.2024; Views: 345; Downloads: 126
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1408. Induction gemcitabine in standard dose or prolonged low-dose with cisplatin followed by concurrent radiochemotherapy in locally advanced non-small cell lung cancer : a randomized phase II clinical trialMartina Vrankar, Matjaž Zwitter, Tanja Bavčar-Vodovnik, Ana Milič, Viljem Kovač, 2014, original scientific article Abstract: The optimal combination of chemotherapy with radiation therapy for treatment locally advanced non-small cell lung cancer (NSCLC) remains an open issue. This randomized phase II study compared gemcitabine in two different schedules and cisplatin - as induction chemotherapy, followed by radiation therapy concurrent with cisplatin and etoposid. Patients and methods. Eligible patients had microscopically confirmed inoperable non-metastatic non-small cell lung cancer; fulfilled the standard criteria for platin-based chemotherapy; and signed informed consent. Patients were treated with 3 cycles of induction chemotherapy with gemcitabine and cisplatin. Two different aplications of gemcitabine were compared: patients in arm A received gemcitabine at 1250 mg/m2 in a standard half hour i.v. infusion on days 1 and 8; patients in arm B received gemcitabine at 250 mg/m2 in prolonged 6-hours i.v. infusion on days 1 and 8. In both arms, cisplatin 75 mg/m2 on day 2 was administered. All patients continued treatment with radiation therapy with 60-66 Gy concurrent with cisplatin 50 mg/m2 on days 1, 8, 29 and 36 and etoposid 50 mg/m2 on days 1-5 and 29-33. The primary endpoint was response rate (RR) after induction chemotherapy; secondary endpoints were toxicity, progression-free survival (PFS) and overall survival (OS). Results. From September 2005 to November 2010, 106 patients were recruited to this study. No statistically signifficant differences were found in RR after induction chemotherapy between the two arms (48.1% and 57.4%, p = 0.34). Toxicity profile was comparable and mild with grade 3/4 neutropenia as primary toxicity in both arms. One patient in arm B suffered from acute peripheral ischemia grade 4 and an amputation of lower limb was needed. With a median follow-up of 69.3 months, progression-free survival and median survival in arm A were 15.7 and 24.8 months compared to 18.9 and 28.6 months in arm B. The figures for 1- and 3-year overall survival were 73.1% and 30.8% in arm A, and 81.5 % and 44.4% in arm B, respectively. Conclusions. Among the two cisplatin-based doublets of induction chemotherapy for inoperable NSCLC, both schedules of gemcitabine have a comparable toxicity profile. Figures for RR, PFS and OS are among the best reported in current literature. While there is a trend towards better efficacy of the treament with prolonged infusion of gemcitabine, the difference between the two arms did not reach statistical significance Keywords: induction chemotherapy, non-small cell lung cancer, radiation therapy, randomized clinical trial Published in DiRROS: 11.04.2024; Views: 537; Downloads: 352
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1409. MRI-assisted cervix cancer brachytherapy pre-planning, based on application in paracervical anaesthesia : final reportPrimož Petrič, Robert Hudej, Omar Hanuna, Primož Marolt, Barbara Šegedin, 2014, original scientific article Abstract: Background. Optimal applicator insertion is a precondition for the success of cervix cancer brachytherapy (BT). We aimed to assess feasibility and efficacy of MRI-assisted pre-planning, based on applicator insertion in para-cervical anaesthesia (PCA). Patients and methods. Five days prior to BT, the pre-planning procedure was performed in 18 cervix cancer patients: tandem-ring applicator was inserted under PCA, pelvic MRI obtained and applicator removed. Procedure tolerability was assessed. High risk clinical target volume (HR CTV) and organs at risk were delineated on the pre-planning MRI, virtual needles placed at optimal positions, and dose planning performed. At BT, insertion was carried out in subarachnoidal anaesthesia according to pre-planned geometry. Pre-planned and actual treatment parameters were compared. Results. Pre-planning procedure was well tolerated. Median difference between the pre-planned and actual needle insertion depth and position were 2 (0%10) mm and 4 (0%30) degrees, respectively. The differences between the pre-planned and actual geometric and dosimetric parameters were statistically non-significant. All actual needles were positioned inside the HR CTV and outside the organs at risk (OAR). Conclusions. Our pre-planning approach is well tolerated and effective. Pre-planned geometry and dose distribution can be reproduced at BT. Keywords: cervix cancer, pre-planning, image-guided brachytherapy Published in DiRROS: 11.04.2024; Views: 327; Downloads: 172
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1410. Mediastinal teratoma with hydrops fetalis in a newborn and development of chronic respiratory insufficiencyMilanka Simončič, Silvester Kopriva, Živa Zupančič, Maja Jerše, Janez Babnik, Matevž Srpčič, Štefan Grosek, 2014, review article Abstract: Background. Mediastinal fetal teratoma can be detected as a mass in the chest during a routine prenatal ultrasound screening. Because of the pressure on mediastinal structures it can be the cause of non-immune hydrops fetalis and polyhydramnion. The development of hydrops fetalis leads to fetal death or premature delivery in most reported cases. Early surgical removal is important, but, the result of treatment depends on the stage of development of mediastinal organs and complications in the postoperative period. Case report. A 31-year-old gravida carrying twins, with spontaneous membrane rupture at 32 weeks gestation underwent urgent caesarean section after antenatal ultrasound revealed severe polyhydramnion and hydrops fetalis in geminus A. The child was intubated immediately after birth due to severe respiratory distress. Ultrasound and X-ray revealed a tumour mass in the right hemithorax. Tumour resection was performed at the age of 7 days. Histology examination revealed an encapsulated immature teratoma. The postoperative course was complicated with respiratory insufficiency which turned into chronic at the age of eight months. Conclusion. This is the fifth reported child with fetal mediastinal teratoma and severe hydrops fetalis that survived the neonatal period. Additional diagnostic search revealed abnormal course of both pulmonary arteries, which was probably one of the main causes of respiratory insufficiency. Keywords: mediastinal teratoma, non-immune hydrops fetalis, diaphragm paralysis, chronic respiratory insufficiency, novorojenčki, mediastinalni teratom, kronična respiratorna insuficienca Published in DiRROS: 11.04.2024; Views: 345; Downloads: 152
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