Judul: Pendugaan NPP (Net Primary Production) Ekosistem Rutan Di Sumatera Barat, Riau dan Jambi Dengan Memanfaatkan Data Noa/Avrrr
Abstrak: The increasing greenhouse gases in the atmosphere, especially CO2• from a period before industrialization to date have resulted in of global warming. International agreement (UNCED 1992, UNFCCC 1994, Protocol Kyoto 1997) have urged nations in the world for active cooperation in reducing concentration of greenhouse gases in atmosphere at storey level which do not endanger for earth. Tropica1 forest represent ecosystem biggest absorber of CO:! (Malhi el at.,I999). Indonesia has a large area of wide tropical forest therefore. will have big contribution in reducing CO:!. NPP (Net Primary Productivity) representing one of method in measuring the ability ecosystem in penneating carbon in atmosphere (June, 2003). Value ofNPP shows accumulation of net CO2 within a one year (gram Carbonlm IN ear) period. It is defined as the difference between total carbon uptake through photosynthesis and losses (through maintance or growth respiration). This research will estimate NPP of spatially from satellite NOAA! A VHRR during year 1996·2000 for West Sumatra, Riau and lambi. Nonnalized Difference Vegetation Index (NDVI) derived from the NOAA·14 AVHRR satellite data were
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Judul: Estimation Of Net Primary Production (NPP) using Remote Sensing Approach and Plant Physiological Modeling.
Abstrak: Net Primary Production (NPP) is the amount of CO2 absorbed and kept inside vegetation per unit area and per unit time. It is a difference between photosynthesis and plant respiration in an ecosystem that can express the net flux of carbon between the atmosphere and terrestrial vegetation. Information NPP of tropical forests is important for the development of realistic global carbon budgets and for projecting how these ecosystems will be affected by climate changes. This research utilized remotely sensed data and micrometeorological measurement to provide information on vegetation condition. The objective of this research is to estimate spatial NPP using remote sensing approach and plant physiological/micrometeorological modeling. The study area is a tropical peat swamp forest at Kalampangan site, Central Kalimantan, Indonesia. Micrometeorological data are used to provide climatic information and input for modeling NPP. The estimation of NPP is conducted using modeling approach, which is based on relationship between radiation use efficiency, photosyntetically active radiation and fraction of absorbed photosynthetically active radiation by the plants' s canopy. Microclimate variation during 2001 - 2002 is relatively low. In June 2002 El Nino phenomenon is started, causing higher air temperature and lower precipitation. Other effects are decreasing of solar radiation and PPFD, due to the shading caused by the smoke emitted from large scale peatland fires. Trend of NDVI derived using micrometeorological measurement showed an increase from 2001 to 2002, and then decrease from 2002 to 2004. Average different values (delta) between both methods used to derive NOVI is relatively constant around 0.33 with a high correlation of r2 = 0.98. Using remotely sensed data, the highest NPP values estimated is in year 2003 with value range between 2000 - 2500 (gC m-2 yr-1), less than 2% of the whole forest area. In 2003, 75% area has NPP between 1500 -2000 (gC m-2 yr-1), meanwhile for 2002 and 2004 it is only 21 % and 50 %, respectively. NPP values estimated using micrometeorological measurement have different values with similar pattern with NPP estimated using remotely sensed data. The pattern is that, NPP increase from 2002 to 2003, and then decrease from 2003 to 2004. The range of yearly NPP for the site is between 2000 -3000 gC m-2 yr-1• The highest NPP for Kalampangan site is in 2003, 2572 gC m-2 yea(1 , followed by 2540 gC m-2 yr-1 NPP in 2001 and 2047 gC m-2 yr-1 NPP in 2004. There is strong correlation between NPP values derived from the two methods with r2 = 0.98. Although the result has high correlation, but further research still needed. This research has been carried out with limited availability of data, with only four observations (of four different years) of satellite data. Increasing CO2 concentration in the atmosphere has resulted in increased simulated NPP values. The increase reached 30% - 31 % under double CO2 concentration in the atmosphere.
Keyword: Net Primary Production, Vegetation Indices, Carbon Cycle, Micrometeorological Modeling, Remote Sensing System

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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