Judul: Kajian Distribusi Spasial dan Temporal Turbulen Menggunakan Data di 15 Lokasi di Indonesia
Abstrak: Turbulence is a type of chaotic and irregular fluid flow which is one of significant weather phenomenon for aviation and air pollution. The distribution pattern of turbulence can be observed by the daily and seasonal patterns and can be classified to understand how strong turbulence events. Turbulence parameters studied were mixed layer height, Richardson number indicating the presence or absence of turbulent, kinetic energy, and turbulence intensity. The study showed that the daily pattern has more significant differences of turbulence parameters than seasonal pattern. Based on the result, turbulence in the fifteen locations are classified as weak turbulence based on convective turbulence intensity and weak to strong turbulence category by the kinetic energy approache.
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Judul: Estimasi Parameter Turbulensi  Untuk Jasa Penerbangan  Berbasis Analisis Data Radiosonde
Abstrak: The one of an important thing related to the aviation is the correct information of aviation meteorology, especially about bad weather condition such as turbulence that often disturb the plane during their flight. There are many parameters to estimate the turbulence parameter. One of them is called the Richardson Number (Ri) such as already investigated by Waco (1970). The author continue his study by applyin g the radiosonde data distributed at five stations in the Western part of Indonesia region, especially during the Coupling Processes Equatorial Atmosphere I (CPEA I) Campaign started from 10 April to 9 May, 2004. The author defined the turbulence when Ri<1 as described by Endlich (1964). We found initial turbulence occurrence indication, although we have found significant indication yet, related with less of locations and data observations which is only one month observation. Turbulence in the plane is described as the changes of vertical gravitation in the plane and observed by vertical accelerometer which is installed in the plane. After making some validations with the vertical accelerometer data, the author found only a few good correlation between Ri and turbulence. We suspect it caused by the less of data observation. But initial indication based on data analysis shows that light turbulence occurrence over Eastern Coast of Malacca Peninsula on 19 April 2004.
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Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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