Judul: Evaluasi Kandungan dan Ketersediaan Mineral Beberapa Jenis Rumput Laut Sebagai Sumber Mineral bagi Ternak Perah.
Abstrak: Indonesia is maritime country which sea area more larger then land area. This is showed that Indonesia’s sea can uses as area for feed production. The prospective maritime plant which content high ash is seaweed. Based on it all, this research aimed to evaluate minerals content and aviabillity (Ca, P, Na, K and Mg) in seaweed use in vitro technicque. Species seaweeds used in this research are Sargassum Sp, Gelidium Sp, Gacilaria Sp, Eucheuma cottonii dan big Eucheuma cottonii. Minerals content in seaweed measured use wet ashing technique. Mineral aviability was measured in 6 and 24 hours on rumen fluid and in 12 hours on HCl. Data of minerals content and minerals solubility in HCl anlysed use descriptive methode, meanwhile data of minerals solubility in rumen fluid anlysed uses ANOVA. The result showed that Phaeophyta dan Rhodophytae which found in Indonesia can uses as macrominerals source, particulaerly for Mg and K source.
Keyword: in vitro, macroalgae, minerals, seaweed, wet ashing

Judul: Potensi Ampas Rumput Laut Gracilaria sp. sebagai Sumber Mineral dalam Ransum Sapi Perah Periode Laktasi.
Abstrak: Penelitian analisis mineral ransum peternak dan ampas rumput laut digunakan untuk mengevaluasi kecukupan kebutuhan mineral dan menyusun premix sebagai suplemen mineral. Berdasarkan kandungan mineralnya, ampas rumput laut lebih cocok digunakan sebagai carrier premix untuk sapi perah laktasi karena mineral esensialnya yang rendah. Selain itu penelitian ini bertujuan mengevaluasi ransum sapi perah yang menggunakan rumput laut dan ampas rumput laut Gracilaria sp. secara in vitro. Penelitian in vitro ransum perlakuan menggunakan rancangan acak kelompok (RAK) 10×4. Perlakuan terdiri atas 10 ransum yang dibedakan berdasarkan jenis konsentratnya. Parameter yang diukur adalah KCBK, KCBO, produksi NH3 dan VFA total dari ransum perlakuan. Data dianalisis menggunakan ANOVA, uji Duncan, uji kontras ortogonal dan polinomial. Hasil in vitro menunjukkan penggunaan 5-20% ampas dan rumput laut dalam konsentrat sapi perah berbeda nyata (P<0.05) terhadap KCBK, dan VFA total dan tidak berbeda nyata (P>0.05) terhadap KCBO dan NH3.
Keyword: ampas rumput laut, Gracilaria sp., mineral, sapi perah

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology