Judul: Analisis Variabilitas Curah Hujan Indonesia pada Kejadian ENSO
Abstrak: Indonesia is one of the countries which experiences El Niño and Southern Oscillation (ENSO) impact on rainfall variability. The purpose of this study included to investigate the Indonesian climate variations related to ENSO events and to understand the effect of ENSO on rainfall temporal distributions at Indramayu (6.35°LS, 108.32°BT) and Tabing (0.88°LS, 100.35°BT). Composite analysis method was used to reveal the trend of sea surface temperature anomaly, wind at 850 hPa, OLR and TRMM 3B43 rainfall data, whereas temporal and correlation analysis was used to observe rainfall and nino-3.4 index. When El Niño sea surface temperature anomaly (ASPL) maximum in October-December, 850 hPa wind backwards from west to east along with increased speed and deviation of OLR below the average values in central and eastern equatorial Pacific which indicates the accumulation of rain cloud. La Niña occurrence is indicated by the deviations of sea surface temperature below average. Low pressure center in Asia reached 850 hPa winds and strengthened Walker circulation, the movement of the air mass brought moisture to Indonesia. Based on the composite of TRMM rainfall, it appeared that the El Niño events gave more significant impact at the end of the year (October to December) on East Indonesia, Java and parts of Sumatra and Kalimantan, while La Niña (December to February) in south and eastern part of Indonesia. Monsoonal pattern (Indramayu) showed ENSO impacts more strongly than equatorial (Tabing). The shift of dry season and low rainfall were affected by ASPL fluctuations on nino-3.4 region.
Keyword: TRMM, SPL, Rainfall, OLR, ENSO

Judul: El Niño Modoki dan Pengaruhnya Terhadap Perilaku Curah Hujan Monsunal di Indonesia
Abstrak: This study aims to investigate El Niño Modoki phenomenon and its influence to the monsoonal rainfall behavior over Indonesia. The study is also intended to identify the differences between the El Nino Modoki and the well-known El Nino events, referred in this study as Conventional El Niño. By using correlation analysis, it is shown that the El Nino Modoki Index, known as EMI, is strongly correlated with SST anomaly index in Nino-4 region. The correlation coefficient value is 0.57, which is higher than the EMI’s correlations with other SST anomaly indices from different Nino regions, i.e. Nino-1.2, Nino-3 and Nino-4. Temporal analysis on both Nino-4 index and EMI by using Power Spectral Density shows a different strength in the temporal cycle of both indices, where Nino-4 data demonstrates a strong 4-5 year interannual cycles, while EMI is dominated by 6–8 years cycles. This is consistent with the result of Wavelet analysis that indicates four years interannual cycles of Nino-4 index and nearly decadal (~10 years) cycles of EMI data. The composite of seven El Nino Modoki events in 1986/87, 1990/91, 1992/93, 1994/95, 2002/2003, 2004/2005, and 2009/2010, generally shows that the El Nino Modoki events indicated by the raise of EMI exceeding its defined threshold usually occurred from July to March. It is shown by clear characteristics of growing phase starting from March or April until January, and continued by decreasing phase around February. Based on the results of regression analysis, the El Nino Modoki strongly influence monsoonal rainfall over Sumbawa Besar, Makassar, and Banjar Baru during both June-July-August (JJA) and September-October-November (SON) periods, over Lampung only during JJA, and Indramayu during SON. The use of EMI which includes information about the SST anomaly around Indonesia led to a significant cross-correlation values between monsoonal rainfall anomaly and EMI with only maximum of one month lag time.
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Judul: Synthesis of Chicken Eggshells-Based β-Tricalcium Phosphate Bioceramics and Their Biocompatibility Test as A Tooth Filler
Abstrak: Preservation of alveolar bone following tooth extraction is an important step in dental practices before dental implant placement. This study reported synthesis of β-Tricalcium Phosphate (β-TCP) bioceramics and its biocompatibility test as a tooth filler to maintain the desired alveolar ridge dimension and stimulate the bone healing processes in the area of tooth loss. β-TCP bioceramics was resulted directly from precipitation of calcinated chicken eggshells as calcium source and phosphoric acid. The corresponding β-TCP was mixed with chitosan 2% to get β-TCP pellet for biocompatibility testing. Biocompatibility testing of β-TCP on lower incisor was performed in rabbits and sheep as animal model. In this study, the x-ray diffraction (XRD) profiles showed that 1000 oC calcinated chicken eggshells correspond to calcium oxide (CaO). There was also transformation phase of CaO into Ca(OH)2 observed after more than three months stored. The XRD profiles proved that obtained β-TCP bioceramics by precipitation has the same pattern with that of reference data base and commercial β-TCP. Fourier transform infrared (FTIR) spectra were completely consistent with the result of crystallization processes observed by XRD measurements. Moreover, the purity of the product shown by the atomic absorption spectroscopy (AAS) resulted in Ca/P ratio of 1.48 which was closed to that of standard β-TCP ceramics. The repeatable XRD peaks patterns and FTIR spectra obviously showed the sample reproducibility. Sheep’s alveolar socket that is filled with the corresponding β-TCP demonstrated the expected results. The x-ray radiograph of sheep’s jaw indicated no change on mesio-distal of the edentulous area. Moreover, the histological results were completely consistent with the x-ray radiograph and macroscopic result which is proved by the formation of new bone. In the contrary with sheep’s result, histological results showed no tooth growth on rabbit proved by the presence of lipid and collagen on the extraction site. This result did not correspond to the x-ray radiograph and macroscopic results that demonstrated the tooth growth and erupted tooth. It is clear that the corresponding β-TCP could minimize the bone loss and maintain the dimension of alveolar ridge.
Keyword: β-tricalcium phosphate, chicken eggshells, rabbit, sheep, tooth filler