Judul: Quantification and Characterization of Bottom Acoustic Backscattering In Seribu Islands – Jakarta
Abstrak: Seabed has a very important role as the habitat for various living creatures, and critical part of aquatic environment. Nowadays, new methods to obtain information on bottom types, sediment characteristics and underwater vegetation in shallow water by using echosounder has flourished. In this paper, normal incident of acoustic waves were used to determine values of bottom backscattering strength (volume backscattering strength (Sv), surface backscattering strength (SS) and echo level (EL)). Sediment properties (acoustic impedance, bulk density, porosity, sound speed and sediment composition) were used to explain the acoustic measurement results. Data collection was carried out in Seribu Islands, Jakarta using SIMRAD EY 60 scientific echosounder systems with operating frequency 120 kHz. The results show that the average value of volume backscattering strength (Sv) for sand is -13,23 dB and silty sand is -21,15 dB. The average value of surface backscattering strength (SS) for sand is -23,30 dB and silty sand is -31,22 dB. The average value of echo level (EL) for sand is 177,94 ± 8,61 dB and silty sand is 167,23 ± 6,07 dB (Source Level (SL) for split beam transducer ES 120-7C series is 214 dB). These acoustics values were then used as input for PCA analysis to cluster seabed characteristics. It’s shown that the acoustic technique can be used to identify and classify sediments and map sediment provinces. Key words: sediment
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Judul: Pengukuran Hambur Balik Akustik Dasar Laut di Sekitar Kepulauan Seribu Menggunakan Split Beam Echosounder.
Abstrak: The purpose of this research is to compute the backscattering strength of the seabed by measuring volume backscattering strength (SV), bottom surface backscattering strength (SS), and the echo level (EL) from seabed using split beam echosounder. The research was conducted from 29th January to 3rd February 2011, around the Seribu Islands: Pramuka island, Panggang island, Karya island and Semak Daun island, North Jakarta. Acquisition of acoustic data was conducted using the SIMRAD EY 60 instrument. Acoustic data obtained from 9 stations simultaneously with sediment sampling. Acoustic processing data was conducted by Rick Towler program with Matlab based. The SV and SS were analyzed Manik et al, model by using. Sediment sampling station consisted of 9 stations: Pramuka island there are 1 station (Station 1), Karya island there are 2 stations (Station 2, and Station 3), Panggang island there are 3 stations (Station 4, Station 7, Station 9), and Semak Daun island there are 3 stations (Station 5, Station 6, Station 8). Sediment classified based on the sediment texture. Seabed surface sediments were separated into 3 types, they are: sand, mud, and clay. This analysis showed that the location of the 9 stations observation is dominated by sand fraction with the percentage of 80.85%. Mud and clay fractions had the average percentage value of 18.32% and 0.83%, respectively. The backscattering value (SV) of sand substrate ranged -10.62 to -18.51 dB with the average of -13.91 dB, and the muddy sand substrate ranged from -16.58 to -25.42 dB with the average -20.57 dB. The value of SS for the sand substrate ranged from -20.70 to -28.58 dB with the average value of -23.98 dB. Muddy sand substrate has a value of SS in the range of -26.64 to -35.49 dB with the average SS of -30.64 dB, from this research, the classification of seabed type using hydroacoustic technology was possible.
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Judul: Pewarisan Genetik Transgen Hd3a pada Tanaman Nicotiana benthamiana Transgenik
Abstrak: Hd3a gene has been successfully introduced into Nicotiana benthamiana genome. In vitro culture, the putative transgenic of N. benthamiana give a flower very early. This plant must be molecularly analyzed to confirm the integration of Hd3a transgene under the control of 35SCaMV promoter in the genome. The objective of this research was to analyze the integration, stability and genetic inheritance of Hd3a transgene under 35SCaMV promoter in transgenic N. benthamiana. Mendelian inheritance pattern of hpt fused to Hd3a transgene with 3:1 ratio has been detected in T1 generation of transgenic N. benthamiana. This pattern showed that transgenic N. benthamiana is heterozygous for hpt fused to Hd3a transgene. In addition, this result indicated that the transgenic N. benthamiana contains one single copy of hpt and Hd3a transgenes integrated in the genome. The molecular analysis showed that T0 and T1 generation of transgenic N. benthamiana contain Hd3a transgene. Hd3a transgene caused an early flowering phenotype in transgenic N. benthamiana E.26.3 line. Average of flowering time in E.26.3 line is 40,5 days after germination. An early flowering character was not observed in E.21.3 line probably caused by the suppression of Hd3a gene.
Keyword: genetic inheritance, Hd3a gene, Nicotiana benthamiana