Uji Daya Hambat Dan Analisis Klt-bioautografi Perasan Buah Sawo Manila (Achras Zapota Linn) Terhadap Bakteri Uji Salmonella Thyposa

The inhibitory effect of juice of Sawo Manilas (Achras zapota Linn) fruit on the growth of tested bacteria Salmonella thyposa Linn by using Thin Layer Chromatography (TLC) Bioautography Method had been done. The aim of this research was to test the ability of the juice as an antibacterial compound in inhibitory bacterial growth and also to know which are the chemical compound in inhibitory bacterial growth and also to know which are of the chemical compound separated by TLC still have antibacterial effect after done TLC Bioautography. The result was show that Sawo manilas fruit was potensially to inhibit the growth of Salmonella thyposa with a large diametric inhibitor zone.The result of TLC-Bioautography ware shown 2 active compound of three.Key Words: Inhibitory, Sawo Manila, TLC-Bioautography, Salmonella Thypos

An experimental study of a cyclonic vertical axis wind turbine for domestic scale power generation

The use of liquid fossil fuel as an energy source has long been considered unsustainable and most importantly the liquid fossil fuel will be diminished by the middle of this century. In addition, the fossil fuel is directly related to environmental degradation and greenhouse emission. Biofuel produced from plants, animals or algae products can offer an alternative to reduce our dependency on fossil fuel and assist to maintain healthy global environment. Micro-algae is becoming popular candidate for biofuel production due to their high lipid contents, ease of cultivation and rapid growth rate. This paper reviews the current stateof- the-art of biofuel from algae as a renewable energy source

Aerodynamic behaviour of small savonius turbine with 3 different configurations

The primary objective of this paper is to study the effect of different configuration of Savonius type domestic scale vertical axis wind turbine with semicircular shaped blades. A 16-bladed rotor was initially designed and its torques and angular speeds were measured over a range of wind speeds using a wind tunnel. The second prototype was designed in such a way that the blades were slightly twisted with the base plate diameter larger than the top plate diameter to enhance the turbine efficiency by directing the air flow to the tip of the base plate to increase the tip speed. The third prototype was designed with the top plate larger than the base plate to enhance the turbine efficiency by directing the air flow to the tip of the top plate. Maximum power curves as a function of wind speeds were established for each configuration. The results show that the rotor design with inverted-pyramid configuration extracted more energy from the wind compared to the straight configuration by around 27.1 % and pyramid configuration by around 48.9 %

Adjacent wake effect of a vertical axis wind turbine

The main objective of this study is to understand the effect of turbine placement and surrounding structures. Using Urban Green Energy's UGE-4K vertical axis wind turbine and the ANSYS computational fluid dynamics package (CFX), a dynamic fluid analysis was undertaken looking at the wake of the turbine through a variety of different inlet speeds and rotational frequencies to determine suitable flow recovery for optimal placement of subsequent turbines. The results showed that the wake interference is minimal at around 5 times the diameter of the turbine downstream. Results also show that flow recovery was a lot slower to the right of the turbine especially along a line 15° from the centre of the turbine to the right as this is coincident with the vortices generated from the turbines rotation

An experimental study of airflow behaviour around a standard 2-man bobsleigh

This paper examines the aerodynamic behaviour of a standard 2-man bobsleigh. Wind tunnel experiments were undertaken on a 50% scale model of 2-man bobsleigh. Wool tufts and smoke were used to visualise the airflow characteristics around the bobsleigh. It was found that the air enters into the bobsleigh cavity through multiple paths. The results suggest that the optimisation of the bumpers, particularly the rear bumpers, is not significantly effective for reducing the aerodynamic drag. Hence, better aerodynamic performance can be achieved by altering the size and shape of the nose as well as the sidewall curvature

An experimental study of new rule javelins

This paper presents a comparative study of three new rule javelins (800g) used in elite competitions. Wind tunnel experiments were conducted on three commercially manufactured javelins (Hart Sports, Nordic Master 60 and Nordic Airglider) to investigate their aerodynamic characteristics. The aerodynamic drag, lift and pitching moment were measured over a range of wind speeds (25 to 33 m/s) for a range of angles of attack from 0 to 35 degree relative to the wind direction. The results suggest that the optimal release angles for each of the javelins are different due to their physical design. The angles of attack for highest lift-to-drag ratio for Hart Sports, Nordic Master 60 and Nordic Airglider javelins were found at 15°, 25° and 30° respectively. The findings of this study also indicate that Airglider javelin has better pitching moment stability than other two javelins

Aerodynamic study of FIFA-approved footballs

The game of football is world's most viewed, played and loved sport. Due to increasing technological advancements and demand for performance, the ball manufacturers have been developing new designs progressively since its inception over 100 years ago. A traditional spherical football made of 32 leather panels stitched together in 1970s has become 14 synthetic curved panels thermally bonded without stitches in 2006 and more recently 8 panels thermally bonded in 2010, and again some new designed balls in 2013. Despite being most popular game in the world, no data is available on aerodynamic properties of recently FIFA approved Adidas Cafusa (thermally bonded 32 panels), Nike Maxim (stitched 32 panels), Umbro Neo 2 Pro (stitched 14 panels, and Mitre Ultimax (stitched 26 panels) footballs. Hence the primary objectives of this study are to evaluate aerodynamic performance of these recently introduced balls and compare their aerodynamic properties. The aerodynamic forces and moments are measured experimentally for a range of wind speeds in wind tunnel. A field trial using professional players has also been undertaken. The aerodynamic forces and their non-dimensional coefficients were determined and compared. The player's perception was also discussed

Aerodynamic drag measurements of FIFA-approved footballs

Increasing technological advancements and demand for performance compel the ball manufacturers to introduce new designs. Construction of spherical footballs has been significantly changed over the years since 1970 from 32-panel leather stitched ball to 8-panel synthetic thermally bonded modern football. Despite being most popular game in the world, no data is available on aerodynamic properties of recently FIFA approved balls such as Adidas Cafusa (thermally bonded 32-panel), Nike Maxim (32- panel stitched), Umbro Neo (14-panel stitched, and Mitre Ultimax (26-panel stitched) footballs. Hence, the primary objective of this study was to determine aerodynamic drag of these balls and compare the findings with other balls introduced in late 2000. The aerodynamic forces were measured experimentally for a range of wind speeds in wind tunnel environment and their nondimensional coefficients were determined and compared. Additionally, a field test was also carried out to understand the perception of professional footballers

Aerodynamics of ribbed bicycle racing helmets

In competitive cycling, aero-helmets have been used around since 1980 to reduce aerodynamic resistance. Considerable design effort has been made to improve the aerodynamic efficiency of racing bicycle helmets over the years. However, the demand for further improvement has forced helmet manufacturers and designers to introduce new designs progressively. Recently several helmet manufacturers (e.g., LG, Lazer and Giro) have introduced dimples on the outer shell of helmet mimicking the so called 'Golf-ball' dimple effects with a view to further reduce aerodynamic drag of the helmet. However, no independently verifiable research so far has been reported in the public domain about the aerodynamic performance of ribbed bicycle helmets compared to smooth surfaced helmets. Hence, the primary objective of this work was to undertake an experimental study on four smooth aero-helmets including two latest model ribbed aero-helmets to understand their aerodynamic performance and the effect of dimples on helmets. The investigation was undertaken in an wind tunnel environment over a range of wind speeds, pitch and yaw angles. The experimental data indicate no measurable advantage between the smooth and ribbed helmets under varied pitch angles and at zero yaw angle

Bio-inspired design: aerodynamics of boxfish

This paper investigates the aerodynamic behavior of a boxfish using both experimental and computational methods. A scaled up model boxfish was manufactured and tested in RMIT Industrial Wind Tunnel under a range of Reynolds numbers and yaw angles. The drag, lift and side forces and their corresponding moments were measured simultaneously. A CAD model of the boxfish was used in CFX FLUENT Computational Fluid Dynamics (CFD) modeling. The CFD modeling data were validated using the experimental findings. The results indicate that the drag coefficient of a boxfish is around 0.10 which is significantly lower than current drag coefficient of a passenger car. Hence, a boxfish shape can be adapted for achieving low drag and energy efficient motor vehicle design