Empirical investigation to explore potential gains from the amalgamation of Phase Changing Materials (PCMs) and wood shavings

The reduction of gained heat, heat peak shifting and the mitigation of air temperature fluctuations are some desirable properties that are sought after in any thermal insulation system. It cannot be overstated that these factors, in addition to others, govern the performance of such systems thus their effect on indoor ambient conditions. The effect of such systems extends also to Heating, Ventilation and Air-conditioning (HVAC) systems that are set up to operate optimally in certain conditions. Where literature shows that PCMs and natural materials such as wood-shavings can provide efficient passive insulation for buildings, it is evident that such approaches utilise methods that are of a degree of intricacy which requires specialist knowledge and complex techniques, such as micro-encapsulation for instance. With technical and economic aspects in mind, an amalgam of PCM and wood-shavings has been created for the purpose of being utilised as a feasible thermal insulation. The amalgamation was performed in the simplest of methods, through submerging the wood shavings in PCM. An experimental procedure was devised to test the thermal performance of the amalgam and compare this to the performance of the same un-amalgamated materials. Comparative analysis revealed that no significant thermal gains would be expected from such amalgamation. However, significant reduction in the total weight of the insulation system would be achieved that, in this case, shown to be up to 20.94%. Thus, further reducing possible strains on structural elements due to the application of insulation on buildings. This can be especially beneficial in vernacular architectural approaches where considerably large amounts and thicknesses of insulations are used. In addition, cost reduction could be attained as wood shavings are significantly cheaper compared to the cost of PCMs

Behavior of FRP-confined normal- and high-strength concrete under cyclic axial compression

An important application of fiber-reinforced polymer (FRP) composites is as a confining material for concrete, both in the seismic retrofit of existing reinforced concrete columns and in the construction of concrete-filled FRP tubes as earthquake-resistant columns in new construction. The reliable design of these structural members against earthquake-induced forces necessitates a clear understanding of the stress-strain behavior of FRP-confined concrete under load cycles. This paper presents the results of an experimental study on the behavior of FRP-confined normal- and high-strength concrete under axial compression. A total of 24 aramid and carbon FRP-confined concrete cylinders with different concrete strengths and FRP jacket thicknesses were tested under monotonic and cyclic loading. Examination of the test results has led to a number of significant conclusions in regards to both the trend and ultimate condition of the axial stress-strain behavior of FRP-confined concrete. These results are presented, and a discussion is provided on the influence of the main test parameters in the observed behaviors. The results are also compared with two existing cyclic axial stress-strain models for FRP-confined concrete. © 2012 American Society of Civil Engineers.Togay Ozbakkaloglu and Emre Aki

Molecular genetics and phylogeny of Ephippigera species group of genus Saga Charpentier, 1825 (Orthoptera: Ensifera: Saginae) in Anatolia

The genus Saga, one of the largest predatory bush crickets and insects in the Palearctic region, is represented by nine species in Anatolia. According to the morphological and bioacoustics evaluations of the Ephippigera species group belonging to the Saga genus, it consists of three species: S. ephippigera, S. syriaca, and S. hakkarica. To the present, however, there is no molecular genetic research on this species group. In our study, by using the 16S rDNA gene sequences, the molecular phylogeny of this species group is revealed and the morphological species hypotheses has been tested. In the study, specimens belonging to S. ephippigera, S. syriaca, and S. hakkarica were collected between the years of 2018 and 2020 with sweep netting; the DNA isolation, polymerase chain reactions, purifications and double-stranded sequencing were performed to obtain 16S rDNA gene sequences. Sequences were evaluated phylogenetically by performing alignment, phylogenetic analysis (Maximum Likelihood and Bayesian Inference), and dating of cladogenetic events, respectively. The monophyletic and species hypotheses of all three species have been supported by molecular data. It has been determined that the S. ephippigera species is the origin lineages of the Ephippigera species group which diverged approximately 0.4 million years ago; it has been also revealed that the climatic changes in the glacial and inter-glacial periods in the Middle Pleistocene period affected greatly the evolution of the species group. Copyright © 2021 Magnolia Press.FM20LTP1We are grateful to Dr. Petru Golban (Tekirdag Namik Kemal University, English Language and Literature) for improving the English of the manuscript. This work was supported by the Research Fund of the Hakkari University (Project numbers: FM20LTP1, Project coordinator M. S. Taylan).proving the English of the manuscript. This work was supported by the Research Fund of the Hakkari University (Project numbers: FM20LTP1, Project coordinator M. S. Taylan)

Modeling approach and analysis time comparison of single-link flexible steel- and epoxy-glass/carbon-fiber composite manipulators

This paper presents different modeling technique approaches of the single-link uniform cross-sectional shape manipulators. Three different materials of manipulators which are epoxy-glass and carbon-fiber for composite manipulators and steel manipulator are considered for both simulation and experimental analyses. Three different modelling techniques which are solid, beam and shell models are used for both manipulators. The study consists of three steps. In the first step, the manipulators are modeled in ANSYS for finite element analyses. In the second step, modal analysis is carried out in order to find the frequencies of the manipulators. In the third step, transient analysis is performed to investigate the success of different modeling approaches with experimental results. It is observed that the simulation results with three different modeling approaches have well matched with the experimental results and then, elapsed times for the transient analyses are investigated to find the appropriate modeling technique for the manipulator. © 2020 Institution of Structural Engineer

Sound insulation of fibre reinforced mud brick walls

The aim of this paper is to find a better alternative for the insulation of industrial noise and to improve the mechanical properties of fibre reinforced mud bricks. It was observed that the fibre reinforced mud bricks fulfill the compressive strength and sound insulation requirements of the ASTM and Turkish Standards. Basaltic pumice as an ingredient was found to improve the sound insulation performance of fibre reinforced mud bricks. The experimental results showed that fibre reinforced mud brick, with basaltic pumice as ingredient, can be used in industrial buildings for walls to improve sound insulation. (C) 2008 Elsevier Ltd. All rights reserved

Sound insulation of fibre reinforced mud brick walls

The aim of this paper is to find a better alternative for the insulation of industrial noise and to improve the mechanical properties of fibre reinforced mud bricks. It was observed that the fibre reinforced mud bricks fulfill the compressive strength and sound insulation requirements of the ASTM and Turkish Standards. Basaltic pumice as an ingredient was found to improve the sound insulation performance of fibre reinforced mud bricks. The experimental results showed that fibre reinforced mud brick, with basaltic pumice as ingredient, can be used in industrial buildings for walls to improve sound insulation. © 2008 Elsevier Ltd. All rights reserved