Judul: Pengukuran Nilai Hambur Balik Plankton di Danau Ranau, Sumatera.
Abstrak: Plankton adalah komponen utama dalam rantai makanan dan indikator kesuburan perairan yang distribusi kelimpahannya tidak merata di perairan. Penelitian ini bertujuan untuk mengetahui distribusi dan kelimpahan plankton secara spasial dan temporal di Danau Ranau melalui pengukuran nilai hambur balik hidroakustik. Penelitian dilakukan pada bulan November 2012 di Danau Ranau, Sumatera dengan metode hidroakustik dan manual sampling. Hasil penelitian menunjukkan bahwa distribusi horizontal berkisar antara -89.99 dB sampai -75.00 dB dan nilai SV terbesar terdapat pada stasiun 2. Nilai SV besar relatif banyak dijumpai di zona litoral (2-6 m) danau. Distribusi vertikal nilai SV menunjukkan perbedaan hasil dengan distribusi kelimpahan plankton dari hasil manual sampling. Nilai SV berkisar antara -82.36 dB sampai -75.03 dB. Nilai SV menunjukkan semakin bertambahnya kedalaman maka nilai SV atau kelimpahan plankton semakin besar sementara kelimpahan plankton dari manual sampling menunjukkan hal sebaliknya. Distribusi temporal kelimpahan plankton bervariasi mengikuti pola intensitas cahaya. Hubungan antara nilai SV kelimpahan plankton dan kedalaman menunjukkan hubungan yang positif tapi tidak erat.
Keyword: Danau Ranau, distribusi spasial, distribusi temporal, hambur balik, plankton

Judul: Hubungan Nilai Volume Backscattering Strength (SV) Plankton dengan Parameter Lingkungan di Perairan Rokan Hilir Bengkalis, Riau
Abstrak: The abundance of fish resource of a water area closely related to the existence of the food resource of the waters. One of the food resources here is plankton organism. The life cycle of plankton, as one of waters organisms, depends on the physical condition of the waters. Measuring the plankton abundance conventionally can use an instrument named planktonnet. However, that method has a weakness in giving spatial information of a wide area, because there will be some areas that is not taken. Better information in spatial and temporal of the Plankton can be given by taking the data acousticly. Acoustic method gives different information, because it can apply directly on the layer waters that will be analyzed. The aim of this research is to see the distribution of Plankton temporally and spatially based on the spread return value, the abundance of plankton net, physical parameter in Rokan Hilir Bengkalis Riau waters. The value of SV tends higher both temporally in the second day and spatially in station 4. The high SV values which dominate are -67,00 and -68,00 dB, that is found the most spatially in Station 4 on the second day at 7 until 8 a.m. It is proper with the abundance of plankton value by using plankton-net, the Station 4 tends higher. The higher plankton abundance is supported by environment parameter, which gives enough influence at every station on the research location. It is proved by the information of axis 1 (F1) and axis 2 (F2) that is 70,29%, moreover the matrix correlation between each parameter gives both positive and negative contribution
Keyword: Volume Backscattering Strangeth (SV) Plankton., Methods Acoustic, Plankton

Judul: Sintesis dan Pencirian Kompleks Fe(III)-Kuersetin
Abstrak: Quercetin belongs to flavonols which is able to chelate metal ions. Quercetin may chelate metal ions at 3’,4’-catechol, 3- or 5-hydroxycromone sites. In this study, quercetin was complexed with Fe(III). The complex with Fe(III) ions from FeCl3·6H2O was more stable than the complex derived from Fe(NO3)3·9H2O. The quercetin was yellow in color and showed maximum wavelengths (λ􀭫􀭟􀭶) at 250 and 370 nm. The Fe(III)-quercetin complex from Fe(NO3)3·9H2O was yellowish green with 􀟣􀭫􀭟􀭶 at 280 and 420 nm, whereas that from FeCl3·6H2O was dark green with 􀟣􀭫􀭟􀭶 at 280 and 430 nm. The 􀟣􀭫􀭟􀭶 shift indicated that the complex was formed at 3-hydroxychromone site. The Fe(III)- quercetin complex was formed with 1:1 metal-ligand mole ratio based on atomic absorption spectrophotometry analysis and the X-ray diffractogram showed that the crystallinity of the complex was 37%.
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