Judul: Pengembangan Sistem Akuisisi Data Kadar Nitrogen Tanah Berbasis Sensor Infra Merah sebagai Pedoman Penentuan Dosis Pemupukan
Abstrak: Site specific nitrogen fertilizing needs an accurate map of soil nitrogen content. The use of sensors operated upon the soil is a promising method since the accurate soil sampling methods are costly and time consuming. The objectives of this research are to determine the relation between soil nitrogen level and near infrared spectrum using artificial neural network (ANN) and to develop soil nitrogen content data acquisition system for static dan dynamic measurement. The results showed that the 1506 nm wavelength can be used to estimate the soil nitrogen content. Furthermore it was found that static measurement showed a better correlation (R2= 0.6286) than the dynamic measurement (R2=0.3111). Combined with the developed ATMega32 microcontroller based display recorder, the precision of N content measurement achieved 0.12% wb with 0.1% wb noise.
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Judul: Rancang Bangun Alat Elektronik Pengukur Indeks Warna Daun Padi Untuk Rekomendasi Pemupukan Nitrogen
Abstrak: Nondestructive nitrogen monitoring for rice leaf is necessary for applying site specific nitrogen recommendation. Electronic SPAD chlorophyll meter device from Konica Minolta and IRRI-Leaf Color Chart now is the most known tools for measuring rice leaf index which have correlated reading with leaf nitrogen content. Both device is using leaf color properties principles to gave index value for estimating leaf nitrogen content. In this research, a new Prototype of leaf color measurement portable device has been build using TAOS TCS230 RGB Color Sensor. This device is using white LED light source to get reflection from rice leaf. Value read from sensor within range 400-600 nm will be processed in microcontroller to gave color value, leaf index and nitrogen fertilizer amount to be applied in the rice field. Performance test result indicate that the device has worked well on distinguishing colors as calibrated with GretagMacbeth color patch. Using BWD calibration the devices display XYZ and RGB color value as well as the BWD unit and fertilizer recommendation.
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Judul: Katalis Eterifikasi Gliserol Berbasis Poli–(asam stirena sulfonat) dari Limbah Styrofoam.
Abstrak: Styrofoam waste can be converted to poly–(sulfonate styrene acid) (PSSA) that can be used as catalyst. The objective of this research is to get PSSA that can catalyze the etherification of glycerol and benzyl alcohol. The styrofoam waste was converted to PSSA by reacting with H2SO4 98% (as sulfonation agent) and P2O5 (as sulfonation catalyst) at 40 °C for 6 hours. Characterizations of PSSA included functional groups, sulfonation levels, water swelling, and thermal stability. The yield of PSSA was 40-55%. The success of sulfonated polystyrene was shown by –SO3H group absorption at 1157.29 cm-1. Etherification of glycerol and benzyl alcohol using PSSA catalyst was conducted at 110 °C for 12 hours. The conversion in producing mono–benzyl ether glycerol was 8.10%, 1,3–dibenzyletherglycerol 2.60%, and dibenzyl ether 9.80%. Therefore, the PSSA can be used as etherification catalyst.
Keyword: benzyl alcohol, etherification, glycerol, polystyrene, PSSA