Judul: Keanekaragaman dan Pola Sebaran Tumbuhan Asing Invasif di Cagar Alam Tangkuban Parahu Sukabumi Jawa Barat
Abstrak: Spesies tumbuhan asing invasif (IAS) merupakan spesies tumbuhan yang berasal dari luar area suatu komunitas lokal dan memberikan dampak negatif dari segi ekologi, ekonomi dan sosial. Penelitian ini bertujuan untuk mengindentifikasi keanekaragaman tumbuhan asing invasif dan mengidentifikasi pola sebaran spesies tumbuhan asing invasif Cagar Alam Tangkuban Parahu. Metode yang digunakan adalah analisis vegetasi kombinasi jalur dan berpetak. Komposisi suku terbesar adalah Moraceae. Spesies tumbuhan asing invasif yang terdapat di Cagar Alam Tangkuban Parahu teridentifikasi sebanyak 7 spesies yaitu Centotheca lappacea, Colocasia esculenta, Digitaria ciliaris, Momordica charantia, Lantana camara, Phyllanthus urinaria dan Swietenia macrophylla. Pola sebaran spesies asing invasif adalah mengelompok.
Keyword: cagar alam tangkuban parahu, keanekaragaman, pola sebaran, spesies tumbuhan asing invasif

Judul: Keanekaragaman dan Pola Sebaran Spesies Tumbuhan Asing Invasif di Cagar Alam Sukawayana, Sukabumi, Jawa Barat
Abstrak: Tumbuhan asing invasif merupakan spesies non-lokal yang menyerang suatu ekosistem yang bukan tempat asli dari spesies non-lokal tersebut. Spesies tumbuhan asing invasif di ekosistem hutan yang terganggu dikhawatirkan dapat mereduksi komposisi vegetasi asli sehingga dapat mengancam keanekaragaman hayati di ekosistem tersebut. Salah satu kawasan konservasi yang diduga diinvasi oleh spesies tumbuhan asing yaitu CA Sukawayana sehingga diperlukan penelitian. Tujuan dari penelitian ini adalah mengidentifikasi struktur dan komposisi vegetasi, keanekaragaman dan pola sebaran spesies tumbuhan asing invasif yang terdapat di CA Sukawayana. Metode yang digunakan yaitu Analisis vegetasi menggunakan metode kombinasi jalur dan garis berpetak. Hasil penelitian menunjukkan bahwa spesies tumbuhan asing invasif di CA Sukawayana teridentifikasi sebanyak lima spesies yaitu Ageratum conyzoides, Ardisia humilis, Centotheca lappacea, Lantana camara, dan Leucaena leucocephala. Pola penyebaran seluruh spesies tumbuhan asing invasif tersebut adalah mengelompok.
Keyword: analisis vegetasi, keanekaragaman, pola sebaran, spesies tumbuhan asing invasif

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.
Keyword: