Judul: Identifikasi spesies nematoda puru akar (Meloidogyne spp.) pada umbi kentang asal Pangalengan dan Kertasari, Kabupaten Bandung, Jawa Barat
Abstrak: Nematoda Puru Akar (NPA, Meloidogyne spp.) merupakan salah satu parasit utama pada kentang. Tanaman sakit akan menampakkan gejala kerdil, menguning atau klorosis, layu dan terbentuknya benjolan-benjolan pada umbi kentang. Hal tersebut dapat menyebabkan penurunan produksi baik kualitas maupun kuantitas umbi kentang. Pengambilan contoh umbi kentang yang terinfeksi nematoda dapat menginformasikan spesies Meloidogyne spp. melalui proses identifikasi. Identifikasi spesies nematoda sangat penting dilakukan untuk merancang strategi pengendalian yang efektif dan efisien. Identifikasi spesies nematoda dilakukan terhadap sampel umbi kentang yang diambil dari daerah Pangalengan dan Kertasari, Kabupaten Bandung. Deteksi keberadaan NPA dilakukan dengan pewarnaan menggunakan Phloxine B konsentrasi 0,1%. Identifikasi spesies NPA dilakukan dengan pengamatan pola perineal nematoda betina di bawah mikroskop cahaya dengan perbesaran 400x. Spesies NPA yang menginfeksi umbi kentang asal Pangalengan adalah Meloidogyne javanica, sedangkan pada umbi kentang asal Kertasari tidak terinfeksi oleh NPA.
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Judul: Identifikasi Spesies Nematoda Puru Akar Penyebab Umbi Bercabang pada Wortel (Daucus carota L.) di Wilayah Kabupaten Semarang dan Magelang, Jawa Tengah
Abstrak: Meloidogyne spp. merupakan patogen penyebab penyakit umbi bercabang pada wortel. Penelitian dilaksanakan untuk mengetahui keberadaan dan mengidentifikasi spesies nematoda puru akar (Meloidogyne spp.) pada sentra pertanaman wortel di wilayah Kabupaten Semarang dan Magelang. Sampel wortel sakit diambil dari tiga lokasi, yaitu ketinggian 1200-1400 m dpl, 1400-1600 m dpl, dan > 1600 m dpl. Gejala penyakit Meloidogyne spp. di lapangan umumnya berupa malformasi pada umbi seperti umbi bercabang, umbi pecah, umbi bulat memendek, dan umbi berambut (hairy root). Tingkat kejadian penyakit sebesar 52%, 63%, dan 67% pada lokasi 1, 2, dan 3. Identifikasi spesies Meloidogyne spp. dilakukan dengan morfologi pola perineal nematoda betina dan PCR. Primer spesifik digunakan untuk mendeteksi M. incognita, M. javanica, dan M. arenaria, sedangkan primer multipleks digunakan untuk mendeteksi M. hapla, M. chitwoodi, dan M. fallax. Empat spesies utama nematoda puru akar, yaitu M. incognita, M. javanica, M. arenaria, dan M. hapla berhasil diidentifikasi dari seluruh lokasi yang diteliti.
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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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