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Extrusion width, the width of printed filaments, affects multiple critical aspects in mechanical properties in material extrusion additive manufacturing: filament geometry, interlayer load-bearing bonded area and fibre orientation for fibre-reinforced composites. However, this study aims to understand the effects of extrusion width on 3D printed composites, which has never been studied systematically.

Four polymers with and without short-fibre reinforcement were 3D printed into single-filament-wide specimens. Tensile properties, mechanical anisotropy and fracture mechanisms were evaluated along the direction of extruded filaments (F) and normal to the interlayer bond (Z). Extrusion width, nozzle temperature and layer height were studied separately via single-variable control. The extrusion width was controlled by adjusting polymer flow in the manufacturing procedure (gcode), where optimisation can be achieved with software/structure design as opposed to hardware.

Increasing extrusion width caused a transition from brittle to ductile fracture, and greatly reduced directional anisotropy for strength and ductility. For all short fibre composites, increasing width led to an increase in strain-at-break and decreased strength and stiffness in the F direction. In the Z direction, increasing width led to increased strength and strain-at-break, and stiffness decreased for less ductile materials but increased for more ductile materials.

The transformable fracture reveals the important role of extrusion width in processing-structure-property correlation. This study reveals a new direction for future research and industrial practice in controlling anisotropy in additive manufacturing. Increasing extrusion width may be the simplest way to reduce anisotropy while improving printing time and quality in additive manufacturing.

This study/paper aims to develop fundamental understanding of mechanical properties for multiple fibre-reinforced materials by using a single-filament-wide tensile-testing approach.

In this study, recently validated single-filament-wide tensile-testing specimens were used for four polymers with and without short-fibre reinforcement. Critically, this specimen construct facilitates filament orientation control, for representative longitudinal and transverse composite directions, and enables measurement of interlayer bonded area, which is impossible with “slicing” software but essential in effective property measurement. Tensile properties were studied along the direction of extruded filaments (F) and normal to the interlayer bond (Z) both experimentally and theoretically via the Kelly–Tyson model, bridging model and Halpin–Tsai model.

Even though the four matrix-material properties varied hugely (1,440% difference in ductility), consistent material-independent trends were identified when adding fibres: ductility reduced in both F- and Z-directions; stiffness and strength increased in F but decreased or remained similar in Z; Z:F strength anisotropy and stiffness anisotropy ratios increased. Z:F strain-at-break anisotropy ratio decreased; stiffness and strain-at-break anisotropy were most affected by changes to F properties, whereas strength anisotropy was most affected by changes to Z properties.

To the best of the authors’ knowledge, this is the first study to assess interlayer bond strength of composite materials based on measured interlayer bond areas, and consistent fibre-induced properties and anisotropy were found. The results demonstrate the critical influence of mesostructure and microstructure for three-dimensional printed composites. The authors encourage future studies to use specimens with a similar level of control to eliminate structural defects (inter-filament voids and non-uniform filament orientation).

This study aims to investigate whether there is a relationship between the religiosity levels of chairpersons’ hometowns and the financial reporting quality of companies.

Using a unique hand-collected data set obtained from various sources, the authors use ordinary least squares and logistic regressions to test the hypotheses and further implement various methods to address potential issues such as omitted variables, reverse causality and selection bias problems. In addition, the authors control for the religiosity level of chief executive officers’ (CEOs) hometowns. Finally, the authors divide the sample into two subsamples – companies with strong corporate governance and companies with weak corporate governance – to investigate the effect of chairpersons’ hometown religiosity on financial reporting quality under strong or weak corporate governance.

The findings demonstrate that companies with chairpersons from religious hometowns produce high-quality financial reports. Additional tests, such as the Heckman selection model and instrument variable regression, confirm the robustness of the main results. Controlling for the religiosity level of the CEO’s hometown yields consistent findings with the main results. Finally, additional results indicate that the religiosity levels of chairpersons’ hometowns play a significant role in enhancing financial reporting quality in companies with weak corporate governance.

Companies should consider appointing board members or chairpersons from more religious hometowns, as the empirical results of this study support the positive effects of chairpersons’ hometown religiosity on financial reporting quality.

To the best of the authors’ knowledge, the current study is among the first to demonstrate the relationship between the religiosity level of the chairpersons’ hometown and the financial reporting quality of companies. The study introduces unique hometown religiosity proxies and controls for various variables related to corporate governance, chairperson attributes, company characteristics, and audit firm characteristics.

In this study, it was aimed to investigate the antibacterial properties of natural pigments prepared from Thymus serpyllum.

Al (III), Fe (II), Sn (II) and Cu (II) complexed natural pigments were obtained by using a precipitation method and the main constituents in the pigments were identified with HPLC-DAD. Also FTIR analysis was performed for further structural characterization. Moreover, the thermal stability and thermal degradation properties of the pigments were analyzed by thermogravimetric analyses (TGA). The antimicrobial activity of the thyme plant-extracted pigments was evaluated by measuring the minimal inhibitory concentration.

Apigenin and luteolin flavones were detected as the main components of the natural dyes. Thermal degradation behaviour of the pigments was determined by means of TGA. All pigments showed high char yields and it was attributed to the high complexation between the metal and the ligand species. The antimicrobial activity of the thyme plant-extracted pigments was measured and it was found that all pigments had high antimicrobial activity. Aluminum-thymus pigments showed the highest antimicrobial efficiency among other pigments used in this study.

The obtained pigments have high antimicrobial activities, and therefore, they can be used for the production of antimicrobial textiles. Furthermore, Thymus-based natural pigments might have potential applications in coating, paint, plastic industries, etc.

The main purpose of this study is to detect homogeneous housing market areas among 196 districts of 5 major cities of Turkey in terms of house sale price indices. The second purpose is to forecast these 196 house sale price indices.

In this paper, the authors use the monthly house sale price indices of 196 districts of 5 major cities of Turkey. The authors propose an autoregressive (AR) model-based fuzzy clustering approach to detect homogeneous housing market areas and to forecast house price indices.

The AR model-based fuzzy clustering approach detects three numbers of homogenous property market areas among 196 districts of 5 major cities of Turkey where house sale price moves together (or with similar house sales dynamic). This approach also provides better forecasting results compared to standard AR models by higher data efficiency and lower model validation and maintenance effort.

In this study, the authors could not use any district-based socioeconomic and consumption behavioral indicators and any discrete geographical and property characteristics because of the data limitation.

The finding of this study would help property investors for establishing more effective property management strategies by taking different geographical location conditions into account.

From the government side, knowing future rises, falls and turning points of property prices in different locations can allow the government to monitor the property price changes and control the speculation activities that cause a dramatic change in the market.

There is no previous research paper focusing on neighborhood-based clusters and forecasting house sale price indices in Turkey. At this point, it is the first academic study.