4 research outputs found
Using recycled bricks to improve the compressive strength of concrete and produce lightweight concrete
No full textThis research presents the aim of using sustainable materials like crushed bricks from the demolition of old buildings as additives to preserve the environment, reduce energy consumption, reduce the cost of concrete, improve the properties of concrete, and obtain lightweight concrete for high buildings with more fluidity for narrow places. Also, it discusses the best replacement ratios because the knowledge about them is still lake. Three mixes of concrete were used and tested. Mix-1was the standard, where the replacement of coarse aggregate with crushed brick aggregate has been used in mix-2, the mix-3 was to study the replacement of fine aggregate by powder brick. In this analysis, only two factors were taken into account: the percentage of coarse aggregate replaced by brick aggregate (from 0 to 50%) and the percentage of fine aggregate replaced by brick aggregate (from 0 to 75%). Compressive strength was tested after curing at ages (7, and 28) days. The results showed that concrete with crushed brick aggregate reduces unit weight and increases of compressive strength of concrete. Using mix-2 increased the compressive strength by about 9.7%, and 7% at ages (7, 28) days respectively, and reduced the weight by 11%. Also, using mix-3 increased the compressive strength with high percentages of about 59%, and 61% at ages (7, and 28) days respectively, with a little percentage of reducing the weight by 2%
HOT BANDS IN OVERTONE ABSORPTION TRANSITIONS: HIGH TEMPERATURE PHOTOACOUSTIC SPECTRA
No full textAuthor Institution: Center for Photochemical Sciences, Bowling Green State UniversityVibrational overtone hot band spectra are presented. The laser photoacoustic spectra of the and overtones of pyrrole, the of methyl isocyanide and acetonitrile. the and of isobutane, and the of cyclohexane were measured at temperatures up to 140C and compared to the room temperature spectra. Hot bands were identified by their temperature dependence. We observed hot bands in pyrrole, methyl isocyanide and isobutane. From the relative intensities of the hot bands to the main band, the wavenumbers of the thermally populated states were and for pyrrole, isobutane and methyl isocyanide, respectively. These values compare well to the bending motion frequencies in these molecules. A large red shift of the hot bands from the main peak was observed, as expected for high overtone transitions due to the large anharmonicity. The anharmonic constants determined from these shifts are for the N-H in pyrrole and for the in methyl isocyanide and cyclohexane. In the case of the absorption the hot band was completely separated from the main transition. In the overtone spectra these hot band absorptions were not separated and result in an apparent increased width of the overtone transition
Enhancing load capacity of reinforced concrete columns using high strength concrete and fiber reinforcement
No full textStrengthening of structural elements is sometimes necessary for architectural purposes to withstand additional loads without cross-section enlargement. This study evaluates the structural performance of reinforced concrete columns toughened using high-strength concrete, steel fiber concrete of 1% volume fraction, and near-surface mounted NSM steel or carbon fiber reinforced polymer CFRP bars. Five columns of 0.15×0.15×1 m were cast and axially loaded till failure. The investigational consequences revealed that a load-carrying capacity and stiffness augmented by 55.1 and 91.1% when the compressive strength is 1.5 times the normal with a ductility decrease of 28.2% whereas steel fiber concrete raised them by 34.3, 6.4, and 11.6%. In addition, NSM steel or CFRP bars exhibited ultimate loads and stiffness 13.6 to 29.7% and 17.2 to 21.7% higher than the non-strengthened column. However, the ductility decreased by 2.5 to 12.4%
Co-creation to Develop Interventions to Facilitate Deep Reflection for Dental Students
No full textCopyright: \ua9 2023 The Author(s). Background: Deep reflective practice is important in healthcare education to allow students to explore emotions associated with the learning experience, access deeper learning and develop their personal and professional identity. Previous research demonstrated that the current methods of reflective practice using logbooks at the end of a clinical session to facilitate reflection within this setting were viewed as suboptimal by staff and student users. To address this problem co-creation, or a \u27students as partners\u27 approach, was used to develop and implement a comprehensive intervention to facilitate deep reflection for undergraduate dental students. This included the production of educational resources, and development of an online safe space to reflect. Approach: In this paper we discuss the process of using co-creation with undergraduate dental students as a research methodology to successfully produce curricular change with respect to reflective practice by involving the voice and experience of student partners. These student partners were part of a team that included researchers and teaching staff and worked with other stakeholders within the institution within a wider team. Evaluation: This paper demonstrates the positive benefits of using co-creation with undergraduate dental students for students such as increased confidence, developing professional and personal skills and impacting meaningful change. Reflection: For researchers and educators, the process gave motivation and enjoyment in curricular development to address pedagogical problems and ensured that the developed intervention was sustainable and appropriate. The paper discusses benefits and challenges of co-creation to develop curricular change. This co-creation approach is recommended for solving similar problems in healthcare education
