We have used first-principles approach to investigate the structural, electronic, magnetic and optical properties of the SGS CoFeTaZ(Z = Si, Ge and Sn) alloys. Our calculated spin-polarized band structures, density of states and projected density of states confirmed that, all the alloys are Type-I spin-gapless semiconductors and half-metallic materials. We reported indirect band gaps with an energy gap of 0.588 eV for CoFeTaSi, 0.434 eV for CoFeTaGe and 0.406 eV for CoFeTaSn in the spin-down channel which confirmed their semiconducting character. Also, we reported metallic character in the spin-up channel for all the compounds. We observed overlap interaction of dd orbitals between Co-3d, Fe-3d and Ta-5d atoms which contributed to the exchange interaction. We reported magnetic moments of 2 mu B and the Curie temperature (Tc); of 385 K for all the alloys. These values suggest that CoFeTaZ(Z = Si, and Sn) can be used; for spin information storage above room temperature. The optical properties such dielectric; functions (real and imaginary), refractive index, reflectivity and transmissivity were examined and reported within the photon energy range of 0-10.0 eV. The present results revealed that SGS CoFeTaZ(Z = Si, Ge and Sn) can be used for spin-optoelectronic applications due to their favorable light absorption, half-metallic feature, high polarization and high Curie temperature value.
This study explored the potency of CTCA in reducing math anxiety and promoting meaningful learning of mathematics among secondary school students. The study adopted a mixed-method (explanatory sequential) design involving a quasi-experimental design and individual in-depth interviews. Participants were drawn from two schools, purposively selected within Lagos state educational district V. Three instruments: Set Theory Achievement Test, Math Anxiety Scale and Students' Perception about CTCA Interview Guide were used to collect the quantitative and qualitative data subsequently. The experimental group (102 students) was taught using the culturo-techno-contextual approach while the control group (106 students) was taught with the traditional lecture method. Treatment lasted six weeks after which posttest and retention test (four weeks after posttest) were conducted. MANCOVA was used to analyze the quantitative data. The results obtained suggest that CTCA reduces math anxiety and enhanced learning achievement [Pillai's Trace = 0.34 (F = 53.09; p<0.01)] more effectively than the traditional teaching method. No significant gender difference was also found in the achievement of the experimental group. Students' perception about the use of CTCA was generally positive. Within the scope and limitations of the study, it was recommended that CTCA should be adopted by secondary school teachers in teaching mathematics concepts.
Purpose Construction industry is a vital sector for economic and national development. However, the industry suffers buildability problems. Improving construction projects buildability is the duty of every key stakeholder. Thus, this study aims to identify and evaluate the project designers’ roles in improving construction projects buildability in Nigeria. Design/methodology/approach This study adopted quantitative research method. A purposive sampling approach was used in identifying the representative sample for the administration of the questionnaire survey. A total of 122 questionnaires were distributed to the targeted construction professionals, out of which 93 questionnaires were sufficiently filled and returned, representing a response rate of 76%. This study used descriptive and inferential statistics for data analyses. Findings The results from factors analysis show that the roles of project designers in improving construction projects buildability in Nigeria can be categorised into two constructs: “discuss fully the design objectives with builders” and “prepare cost effective and buildable designs”. Originality/value This study contributed to more effective buildability studies by highlighting the roles of project designers in improving construction projects buildability in the construction industry. An understanding of these roles is vital for reducing buildability problems as well as for improving and embedding buildability as a practice in construction management.
Editor’s Note: The following Letter to the Editor, by Dan Bergland, is an opinion piece that offers Mr. Bergland’s perspective on an article published by Ben Armstrong in the August 2021 issue of Economic Development Quarterly (EDQ), titled “Industrial Policy and Local Economic Transformation: Evidence from the U.S. Rust Belt.” Mr. Berglund’s Letter to the Editor is accompanied by a response from Ben Armstrong. The publication of these two pieces reflects EDQ’s commitment to open dialogue from a variety of perspectives.
This work investigates the influence of banana (Musa Sapientum) and jute fibers as a reinforcement in a cement/waste brown paper pulp matrix for applications in housing construction in Nigeria.The natural fibers were extracted from banana trunk and cocoa sack and, thereafter, treated with 1-M sodium hydroxide (NaOH) for 2 h to expose the lignin and cellulose and thus expose the hemicellulose content of the fibers.The treated fibers were allowed to dry in air for 7 days before cutting into short fibers of 10 mm length.Paper pulp was prepared by soaking waste brown cardboard papers in water for 24 h, thereafter, it was grinded in the paper pulp machine to form a paper pulp slurry, and then sun-dried for 5 days.The treated fibers were thoroughly mixed with the dried paper pulp to develop Fiber Cement Board (FCB) samples of varied weight content (5, 10, 15, and 20) w/% using the hand lay-up technique with the aid of a cold compacting machine.Thereafter, an appropriate quantity of cement as binder and treated sugarcane bagasse as filler material were added to the mix.The developed FCB samples were allowed to cure in air in the laboratory for 28 days before testing.Flexural, compressive, thermal conductivity, and water absorption tests were carried out on the samples using a universal testing machine, Lee's disk apparatus, and the percentage weight of different immersed samples in water, respectively.The results of the mechanical properties examined showed that FCB sample D containing (10 w/% banana fiber, 10 w/% jute fiber, 15 w/% cement/bagasse and 65 w/% paper pulp) gave the optimum results for the flexural and compressive properties with a respective value of 0.843 MPa and 7.333 MPa, while FCB sample F gave the best results for the thermal conductivity and water-absorption property.
