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: 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: Resonance technique HHO generator for internal combustion engine
Abstrak: Application of HHO gas as fuel had been generaly used. Though there was still controversy regarding its efficiency and efectiveness . In this research, hydrogen that hopefully could become an alternative renewable energy was produced by the electrolysis process. HHO was the mixture of hydrogen gas and oxygen gas that was formed in HHO dry generator. In HHO cell (dry) generator contained 10 cells, and each cell required 2.4 voltage. Furthermore, resonance DC application was evaluated to gain the better electrolysis efficiency. The test was held by using 2 level of electrolyte consentration, 0.178 M KOH and 0.446 M KOH. Each concentration was tested by 3 size of inductors, 8uH, 40uH, and 100uH. Not only single frequency was used, but modulatedfrequency was used also as well. In order to measure the improvement of resonance techinique application, specific energy was compared between using resonance technique and conventionaltechnique.Specific energy was calculated between output (mass of hydrogen) and input energy (watt hour). In this test,input of specific energy was measured in two condition:energy from the source (total) and energy in HHO generator only. From the test, it could be concluded that modulated frequency, by using40 Hz and 2405 Hz frequency, 100uH inductor, and 0.446 M OH, only 61% of total specific energy that was used in HHO generator. It needed23.91 watt hour energy (total) to produce 1 gram of hydrogen gas.On the other hand, the worst performance was happened in single frequency, 11270Hz, 8uH of inductor, and 0.178 KOH, where the loss of specific energy was 82%. The conventional technique only loosed about 0.5% of specific energy in 0.178 KOH needed 51.37watt hour to provide one gram of hydrogen. The loss was happened due to the excess of current that was converted into head in MOSFET. Hopefully the further research will be held again by using wet type of HHO generator because dry generator did not have fixed capacity value and it maked difficulty for calculating the perfect resonance condition.
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