Judul: Variasi Morfologi Polen Beberapa Spesies Tanaman Pekarangan
Abstrak: Informasi mengenai keragaman polen sangat bermanfaat dalam menunjang berbagai disiplin ilmu. Karakter polen yang tahan terhadap pengaruh lingkungan maupun terhadap oksidasi selama proses fosilisasi dapat menjadi sumber data yang sangat penting. Data tentang polen banyak dipakai dalam ilmu forensik terkait investigasi pelaku tindak kriminal. Penelitian ini bertujuan mengidentifikasi variasi morfologi polen tanaman pekarangan. Sampel polen dari 22 spesies tanaman diambil dari 13 pekarangan rumah penduduk di kawasan Kota Pekanbaru dan satu spesies tanaman pekarangan diambil dari kampus IPB University, Bogor. Pengambilan bunga dilakukan berdasarkan jumlah spesies terbanyak dari suatu famili yang telah ditemukan. Pengamatan morfologi polen dilakukan terhadap 23 spesies tanaman dari famili Apocynaceae, Convolvulaceae, Cucurbitaceae, Oxalidaceae, dan Solanaceae. Sediaan polen dibuat dengan metode asetolisis standar. Karakter morfologi polen yang diamati adalah bentuk polen dari sisi polar dan ekuatorial, ukuran rata-rata polen, tipe aperture, dan tipe ornamentasi eksin. Hasil pengamatan menunjukkan bentuk polen dari sisi polar dan ekuatorial untuk seluruh spesies dari seluruh famili yaitu berupa circular dan circular oval. Ukuran rata-rata polen sangat beragam, mulai dari berukuran kecil hingga sangat besar. Tipe aperture tricolporate ditemukan pada famili Apocynaceae, Cucurbitaceae, dan Solanaceae. Famili Convolvulaceae tipe aperture berupa pantoporate, dan Oxalidaceae memiliki aperture tipe tricolpate. Tipe ornamentasi eksin berupa psilate ditemukan pada famili Apocynaceae, Cucurbitaceae, Oxalidaceae, dan Solanaceae, sedangkan famili Convolvulaceae bertipe echinate., Information about the diversity of pollen is very useful in supporting various disciplines. The character of pollen that is resistant to environmental influences and to oxidation during the fossilization process can be a very important of data source. Pollen data are widely used in forensic science related to criminal investigations. This study aimed to identify variations in the pollen morphology of garden plants. Pollen samples of 22 plant species were taken from 13 house gardens in Pekanbaru and one species of garden plant was taken from IPB University, Bogor. Flower collection is carried out based on the highest number of species from a family that has been found. Pollen grains morphology observations were carried out on 23 species belonging to the families Apocynaceae, Convolvulaceae, Cucurbitaceae, Oxalidaceae, and Solanaceae. Pollen slides were prepared by acetolysis standard method. The morphological characters of pollen grain observed were pollen shape from polar and equatorial view, pollen size, aperture type, and exin ornamentation. The result showed that pollen shape from the polar and equatorial view of all species was circular and circular oval respectively. The size of pollen grains were varied greatly, ranging from small to very large sized. The tricolporate aperture types were found in the Apocynaceae, Cucurbitaceae, and Solanaceae. The Convolvulaceae were pantoporate, and Oxalidaceae had a tricolpate type. Exin ornamentation in the form of psilate was found in Apocynaceae, Cucurbitaceae, Oxalidaceae, and Solanaceae, while in the Convolvulaceae was sculpturing echinate.
Keyword: acetolysis, aperture, exin ornamentation, polar and equatorial view, pollen size

Judul: Morphology of Pollen Collected by Honey Bee Apis cerana and Apis nigrocincta in Central Sulawesi
Abstrak: Keanekaragaman tumbuhan sumber polen dapat mendukung konservasi lebah. Namun, informasi tumbuhan sumber polen lebah Apis cerana dan Apis nigrocincta di Sulawesi belum dilaporkan. Penelitian ini bertujuan mengidentifikasi tumbuhan (berdasarkan morfologi polen) dan mengelompokkan tipe polen ke dalam kategori nilai pentingnya sebagai sumber pakan A. cerana dan A. nigrocincta di Sulawesi Tengah. Metode penelitian meliputi pengamatan warna bee pollen, preparasi polen dengan asetolisis, pengamatan morfologi dan identifikasi tipe polen, serta pengelompokkan tipe polen ke dalam kategori nilai penting. Hasil penelitian menunjukkan preferensi A. cerana terhadap sumber polen yang lebih beragam (16 tipe polen) dibandingkan A. nigrocincta (satu tipe polen). Cocos nucifera merupakan sumber polen predominant bagi A. cerana dan A. nigrocincta. Polen dari lima spesies tumbuhan lainnya dan polen gramineae termasuk dalam kategori important minor bagi A. cerana, sedangkan polen dari sembilan spesies tumbuhan lainnya termasuk kategori minor. Sebagian besar sampel bee pollen dari A. cerana dan A. nigrocincta berwarna dark yellow, dan bee pollen dengan warna sama dapat memiliki tipe polen predominant dari spesies tumbuhan berbeda. Tumbuhan sumber polen A. cerana berhabitus pohon, semak, dan herba; sedangkan sumber polen A. nigrocincta hanya dari tumbuhan berhabitus pohon., Diversity of pollen sources plants could supported bee conservation. However, the information on pollen source plants for Apis cerana and Apis nigrocincta in Sulawesi has not been reported. This study aimed to identify the plants (based on the pollen morphology) and to group pollen type into the important value categories as food sources for A. cerana and A. nigrocincta. The methods were used observing bee pollen color, identifiying pollen type based on the morphological characters, and grouping the pollen type into its importance categories. The results showed A. cerana has more differs preference on food sources (16 pollen types) compared to A. nigrocincta (one pollen type). Cocos nucifera was the predominant pollen sources for both A. cerana and A. nigrocincta. The gramineae pollen and five other pollen types were included in important minor category for A. cerana, while nine other pollen type were in the minor category. Most of the bee pollen collected from A. cerana and A. nigrocincta was dark yellow. Bee pollens have similar color might have different predominant pollen type. The pollen sources plants of A. cerana were trees, shrubs, and herbs, but only trees for A. nigrocincta.
Keyword: Apis nigrocincta, bee forage plants, important minor pollen, predominant pollen, Sulawesi

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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