Judul: Rancang Bangun Pendeteksi Otomatis Ketinggian Permukaan Air Berbasis Sensor Medan Magnet UGN3503
Abstrak: An automatic detector of water level with sensor UGN3505 as detector of changes water level has been successfully be made for this research. Sensor UGN3505 is a hall effect sensor which works based on the large magnetic fields on the surface. The output voltage generated by the sensor without the influence of a magnetic field is 2,525 volts, the output voltage is different than it should be 0.025 volts is 2.50. This shows that the sensor is not completely free from magnetic field sources, there is still the effect of the Earth's magnetic field to the sensor. Sensor output voltage will increase, with increasing magnetic field on the surface of the sensor. As the central data processing equipment, used microcontroller ATmega16. The input of microcontroller is the changes output voltage of sensor than has been converted into digital data (internal ADC ATmega16) caused the changes of magnetic field. The digital data are readable by microcontroller be processed and displayed in the 16x2 LCD, LED indicator and buzzer. Programs created using software tools CVAVR with C + + language.
Keyword: Sensor UGN3505, magnetic field, hall effect, CVAVR, ATMega16, DC

Judul: Rancang Bangun Alat Pengukur Intensitas Hujan Dengan Metode Jungkat-Jungkit Berbasis Sensor Medan Magnet UGN3503.
Abstrak: This research has been done on making rain intensity gauge using a magnetic field sensor UGN3503. Sensor UGN3503 can detect the magnetic field on its surface. The sensor is placed above a seesaw that was inserted magnet. The magnet used is Neodymium magnet is a type of permanent magnet with stongest magnetic field compared to other types of fixed magnetic field magnets. When the seesaw discards rainwater, the distance between sensor and magnet is closer and causing the keluaran voltage of the sensor increases. The keluaran voltage of the sensor is compared with a reference voltage by the comparator so that the sensor keluaran data is in digital form and ready to be processed. As the processing and sending of data used ATmega16 microcontroller, microcontroller take sensor data once every 100 ms and display data to the LCD (Liquid Crystal Display) 16x2. Every 30 minutes the data is processed into the rain intensity is then stored into a computer.
Keyword: rain intensity, seesaw, comparator, microcontroller, sensor UGN3503.

Judul: Revisi marga Ptychopyxis miquel (Euphorbiaceae) di kawasan Malesia
Abstrak: Ptychopyxis adalah salah satu marga dari 317 marga yang termasuk ke dalam suku Euphorbiaceae. pertama kali dipublikasikan oleh Miquel (1860). Marga ini Marga ini pernah dimasukkan kedalam marga lain, yaitu Podadenia, Mallotus dan Clarorivinia. Fakta tersebut menunjukkan bahwa batasan marga Ptychopyxis belum cukup mantap. Persebaran marga ini menurut Van Welzen (1993) jumpai di Thailand, Indochina dan kawasan Malesia, di seluruhnya ada 23 jenis dan 10 jenis diantaranya terdapat di kawasan Malesia. Marga ini umum berperawakan pohon dan berumah dua, tumbuh di hutan hujan dataran rendah sampai pada ketinggian 1500 m dpl. Penelitian taksonomi yang komprehensif tentang marga ini telah dilakukan oleh Airy Shaw pada tahun 1960; sejak saat itu belum ada penelitian taksonomi yang lebih kompre- hensif, khususnya untuk kawasan Malesia. Kini dengan bertambahnya jumlah spesimen koleksi baru, maka tepatlah kiranya dilakukan revisi marga. Tujuan penelitian ini adalah untuk memberikan batasan marga serta jenis-jenisnya yang termasuk dalam Ptychopyxis selain itu diteliti pula hubungan kekerabatan antar jenis dan keterangan-keterangan..dst
Keyword: Herbarium Bogoriense, Podadenia, Mallotus, Clarorivinia