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This paper aims to achieve an optimum flow separation control over the airfoil using a passive flow control method by introducing a bio-inspired nose near the leading edge of the National Advisory Committee for Aeronautics (NACA) 4 and 6 series airfoil. In addition, to find the optimised leading edge nose design for NACA 4 and 6 series airfoils for flow separation control.

Different bio-inspired noses that are inspired by the cetacean species have been analysed for different NACA 4 and 6 series airfoils. Bio-inspired nose with different nose length, nose depth and nose circle diameter have been analysed on airfoils with different thicknesses, camber and camber locations to understand the aerodynamic flow properties such as vortex formation, flow separation, aerodynamic efficiency and moment.

The porpoise nose design that has a leading edge with depth = 2.25% of chord, length = 0.75% of chord and nose diameter = 2% of chord, delays the flow separation and improves the aerodynamic efficiency. Average increments of 5.5% to 6° in the lift values and decrements in parasitic drag (without affecting the pitching moment) for all the NACA 4 and 6 series airfoils were observed irrespective of airfoil geometry such as different thicknesses, camber and camber location.

The two-dimensional computational analysis is done for different NACA 4 and 6 series airfoils at low subsonic speed.

This design improves aerodynamic performance and increases the structural strength of the aircraft wing compared to other conventional high lift devices and flow control devices. This universal leading edge flow control device can be adapted to aircraft wings incorporated with any NACA 4 and 6 series airfoil.

The results would be of significant interest in the fields of aircraft design and wind turbine design, lowering the cost of energy and air travel for social benefits.

Different bio-inspired nose designs that are inspired by the cetacean species have been analysed for NACA 4 and 6 series airfoils and universal optimum nose design (porpoise airfoil) is found for NACA 4 and 6 series airfoils.

The purpose of this paper is to achieve an optimum flow separation control over the airfoil using passive flow control method by introducing bio-inspired nose near the leading edge of the NACA 2412 airfoil.

Two distinguished methods have been implemented on the leading edge of the airfoil: forward facing step, which induces multiple accelerations at low angle of attack, and cavity/backward facing step, which creates recirculating region (axial vortices) at high angle of attack.

The porpoise airfoil (optimum bio-inspired nose airfoil) delays the flow separation and improves the aerodynamic efficiency by increasing the lift and decreasing the parasitic drag. The maximum increase in aerodynamic efficiency is 22.4 per cent, with an average increase of 8.6 per cent at all angles of attack.

The computational analysis has been done for NACA 2412 airfoil at low subsonic speed.

This design improves the aerodynamic performance and increases structural strength of the aircraft wing compared to other conventional high-lift devices and flow-control devices.

Different bio-inspired nose designs which are inspired by the cetacean species have been analysed for NACA 2412 airfoil, and optimum nose design (porpoise airfoil) has been found.

The purpose of this paper is to investigate the effect of surface protrusions on the flow unsteadiness of NACA 0012 at a Reynolds number of 100,000.

Effect of protrusions is investigated through numerical simulation of two-dimensional Navier–Stokes equations using a finite volume solver. Turbulent stresses are resolved through the transition Shear stress transport (four-equation) turbulence model.

The small protrusion located at 0.05c and 0.1c significantly improve the lift coefficient by up to 36% in the post-stall regime. It also alleviates the leading edge stall. The larger protrusions increase the drag significantly along with significant degradation of lift characteristics in the pre-stall regime as well. The smaller protrusions also increase the frequency of the vortex shedding.

The effect of macroscopic protrusions or deposits in rarely investigated. The delay in stall shown by smaller protrusions can be beneficial to micro aerial vehicles. The smaller protrusions increase the frequency of the vortex shedding, and hence, can be used as a tool to enhance energy production for energy harvesters based on vortex-induced vibrations and oscillating wing philosophy.

The purpose of this paper is to reveal the contribution of the digital storytelling to the peer assessments experiences of pre-service teachers within the teaching practices.

The study is carried out as a special case study. Both qualitative and quantitative data gathering tools were used together to investigate a special case in depth (Yıldırım and Şimşek, 2011; Çepni, 2007). In this study, the case investigated was the process whereby the senior year pre-service teachers enrolled in the faculty of education provided assessments of themselves and their peers through the teaching practice course, using digital storytelling. The contributions of the assessment method employed, in the experiences and personal development of the pre-service teachers, were investigated through interviews with pre-service teachers involved.

The results suggested that pre-service teachers’ perspectives were quite positive toward the use of digital storytelling for peer assessment in their teaching practices. The prominent contributions were: they caused easily tolerate personally as they did not take a direct form, and that they considered peer assessment through digital storytelling as an alternative means of assessment to effectively reflect the process. Receiving more detailed feedback about their classroom experiences and their teaching skills was helpful for pre-service IT teachers. Suggestions due to the findings were also included.

In the study, peer assessment digital stories in the teaching practice courses offers the benefits of confidence with, different perspectives, satisfaction, and objectivity. These benefits can help pre-service teachers to focus on shortcomings regarding their teaching experiences, and take care for the correction. Further studies can be provided about the digital storytelling processes in various assessment processes of the instructions to reveal the potential of digital narratives in other domains as well.

The present paper seeks to determine the prevalence of Salmonella spp. and Listeria (L.) monocytogenes in several cheese varieties.

A total 280 cheese samples (105 white cheese, 70 processed cheese, 45 dil cheese and 60 kasar cheese) purchased from supermarkets in six provinces of Turkey were collected at intervals between March 2007 and February 2008.

The results showed that 1.9 percent of white cheese samples were contaminated with Salmonella spp, whereas the L. monocytogenes prevalence was 4.8 percent in this type of cheese sample. The prevalence of L. monocytogenes in processed cheese and kasar cheese were found to be 1.4 percent and 1.7 percent, respectively. No Salmonella spp. was isolated from these cheese varieties. Neither Salmonella spp. nor L. monocytogenes were found in dil cheese samples examined.

Cheese is a ready to eat product that with a low incidence of contamination may pose great public health concerns. Microbiological evaluation of different cheese samples produced with different manufacturing methods and the possible effects of manufacturing methods on the microbiological quality of these cheese samples are the originality criteria of the study. The cheeses were also sold in a very restricted area of Turkey. The results of this study indicate that white cheese has the highest rates of contamination due to the lack of standardized procedures of manufacturing and ripening.

The purpose of this paper is to explore the tribological properties of high-density polyethylene (HDPE) modified by carbon soot from the combustion of No. 0 diesel.

Carbon soot is characterized using X-ray diffraction, transmission electron microscopy and scanning electronic microscopy. The tribological properties of HDPE samples with carbon soot are investigated on a materials surface tester with a ball-on-disk friction pair.

The collected carbon soot mainly comprises amorphous carbon nanoparticles of 50-100 nm in diameter. The main wear behaviours of pure HDPE include abrasive wear and plastic deformation. After adding carbon soot nanoparticles to HDPE, HDPE wear decreases. The appropriate carbon soot content is 8 per cent in HDPE under the selected testing conditions. Compared with other HDPE samples, HDPE with 8 per cent carbon soot has higher melting temperature, lower abrasive wear and better wear resistance. The lubrication of HDPE with carbon soot is due to the formation of a transferring film composed of HDPE, amorphous carbon and graphite carbon.

The paper reveals the HDPE modification and lubrication mechanisms by using carbon soot from the combustion of diesel. Related research can perhaps provide a potential approach for the treatment of carbon soot exhaust emission.