Judul: Keanekaragaman dan Pola Sebaran Spesies Tumbuhan Asing Invasif di Cagar Alam Dungus Iwul, Bogor
Abstrak: Dungus Iwul Nature Reserve is one of the conservation area that is supposed getting invacived by alien plant species. The purpose of this research is to identify the composition and structure of forest vegetation, diversity and distribution patterns of invasive alien plant species in Dungus Iwul Nature Reserve. Data was colected by vegetation analysis with squared track and line combination. The composition of plant species that is identified in Dungus Iwul Nature Reserve consist 69 species of 34 families wich mostly Euphorbiaceae. Identified of invasive alien plant species consist 6 species from 4 families. They are: Clidemia hirta (Melastomataceae), Ageratum conyzoides (Asteraceae), Cynodon dactylon (Poaceae), Chromolaena odorata (Asteraceae), Mikania micrantha (Asteraceae) and Piper aduncum (Piperaceae). The distribution patterns of invasive alien plant species based on Morisita index was clumped
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Judul: Keanekaragaman dan Pola Sebaran Spesies Tumbuhan Asing Invasif Di Cagar Alam Yan Lapa
Abstrak: Invasive alien plants species were plant species which come from other regions or countries and gift negative impact to the native species diversity. This research aimed to identify the vegetation composition and structure, invasive alien plant species diversity, and distribution pattern of invasive alien plant species in Yan Lapa Nature Reserve. The methods used were vegetation analysis using combination of line transect and nested plot and rapid assessment. The most dominant family was Araceae. As many as twelve invasive alien plants species were identified exist in Yan Lapa Nature Reserve. Those twelve species were Acmella uliginosa, Ageratum conyzoides, Centotheca lappace, Cyathula prostrata, Paspalum conjugatum, Clidemia hirta, Chromolaena odorata, Elephantopus scaber, Mikania micrantha, Cecropia peltata, Swietenia macrophylla dan Lantana camara. All invasive alien plant species distribution patterns were clustered.
Keyword: Bogor Agricultural University (IPB), distribution pattern, invasive alien plants species, Yan Lapa Nature Reserve, Vegetation analysis

Judul: Sintesis BaTiO3 dari Campuran Ba(OH)2 dan TiO2 dengan Tambahan PbO
Abstrak: Piezoelectric material can generate electric field in response to applied mechanical stress. Conversely, they can stretch and contract in response to an electric field. This material can be used for many applications such as transducer, microphone, ultrasound, and pressure gauge. Barium titanate is a ferroelectric material with piezoelectric properties that can be synthesized easily. The aim of this study is to synthesis barium titanate from mixture of Ba(OH)2 and TiO2, also observe its optimum temperature and the effect of PbO addition. The method of synthesis was solid-state reaction and sol-gel method, then the products were characterized with x-ray diffraction (XRD). Based on XRD analysis, the optimum temperature for both methods was 800°C. Addition of PbO to BaTiO3 in the solid-state reaction formed a compound with formula of Ba1-xPbxTiO3. The addition has changed diffraction pattern peak at 2θ and strengthened its tetragonal structure. The best result was obtained at x of 0.5 which will form a compound of Ba0.5Pb0.5TiO3.
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