Judul: Analisis Pola Sebaran Hujan Bulanan dan Kaitannya dengan Pola Tanam Palawija di Beberapa Daerah Sulawesi Utara
Abstrak: Tujuan penelitian ini ialah untuk mengetahui sifatsifat hujan bulanan dan pola sebarannya di beberapa daerah pertanaman palawija Sulawesi Utara, guna menentukan pola tanam di lahan kering sesuai dengan kebutuhan curah hujannya. Analisis curah hujan model periodik yaitu menganalisa jumlah curah hujan sedemikian rupa sehingga daripadanya dapat diketemukan sifat-sifatnya yang tersembunyi yang datang berulang pada tiap periode tertentu seperti musim hujan dan musim kemarau yang datang silih berganti secara periodik. Gunanya dapat memperkirakan sifat hujan yang akan terjadi beberapa bulan yang akan datang, sehingga dapat diperkirakan pada bulan-bulan tertentu akan terjadi kekeringan dan atau kebasahan. Hal ini penting bagi program-program pertanian untuk penentuan awal dan akhir musim tanam. Sedangkan analisis korelasi diri digunakan untuk mengetahui keeratan hubungan dari setiap periode curah hujan bulanan.
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Judul: Penentuan masa tanam padi dan palawija (jagung) berdasarkan analisis neraca air dan kebutuhan air tanaman di lahan tadah hujan daerah Jaken, Jakenan dan Puncak Wangi, Pati, Jawa Tengah
Abstrak: Penelitian ini bertujuan untuk mengetahui gambaran umum mengenai: (1) Pola sebaran hujan sepanjang tahun dan kandungan air tanahnya (menurut waktu/dekade), (2) Masa tanam menurut FAD (1978) dan berdasarkan kebutuhan air bagi tanaman dan (3) Pola tanam padi dan jagung (palawi- ja), berdasarkan masa tanam dan periode tanam yang terse- dia bagi tanaman padi dan jagung (palawija) di lahan tadah hujan daerah Jaken, Jakenan dan Puncak Wangi, Pati. Jawa Tengah. Tahapan penelitian ini meliputi: Analisis data curah hujan yang sudah dikelompokkan dari data 30 tahun menjadi data seri 10 tahunan dan maju 5 tahun kedepan (dekade), berdasarkan matrik korelasi serta uji analisis komponen utama (paket program statistika minitab release 6.1); Penentuan awal musim hujan berdasarkan nilai curah hujan lebih dari atau sama dengan 50 mm; Perhitungan ETP dengan rumus Blaney-Criddle (yang sudah diubah); Penentuan masa tanam menurut FAO (1978) dan kandungan air tanahnya; Penentuan nilai kapasitas lapang dan titik layu berdasar- kan pendekatan peta sebaran tekstur tanah dan grafik ...
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Judul: Glucose biosensor using a glucose dehydrogenase flavin adenine dinucleotide electrochemically immobilized on zeolite nanoparticles
Abstrak: A glucose biosensor was developed to measure blood glucose levels. The performance of these new glucose biosensors was continuously improved, producing better performance and stability. The technique selection and immobilization matrix are key factors for biosensor development, so that the prospecting of materials that can be used as a matrix for supporting enzyme, continue to be explore. The purpose of this study was to determine the activity and stability of the enzyme glucose dehydrogenase (GDH) that were immobilized on zeolite nanoparticles (NPZ) and determine the kinetic parameters and analytical performance by electrochemical methods. The resulting enzyme electrode with NPZ and enzyme electrode with zeolite A showed a high activity against the enzyme electrode glucose than without NPZ. The reaction kinetics of third electrodes of enzyme followed the Dixon equation. The 𝐼����𝑚����𝑎����𝑥����𝑎����𝑝����𝑝���� values for enzyme electrode without NPZ, with NPZ, and with zeolite A were 27.25 μA, 77.52 μA, and 48.54 μA, respectively. The 𝐾����𝑀����𝑎����𝑝����𝑝���� values for GDH enzyme that immobilized on the NPZ were 1.16 mM, 12.30 mM for GDH enzyme that immobilized on zeolite A and 0.95 mM for GDH enzyme immobilization without NPZ. The enzyme electrode without NPZ, with NPZ, and with zeolite A also showed a high sensitivity with value for the sensitivity were 0.58 μA mM-1, 0.81 μA mM-1, and 2.51 μA mM-1, respectively. The third enzyme electrodes showed different linear area with range for the enzyme electrode without NPZ, with NPZ and with zeolite A were 1.00-15.00 mM, 2.00-20.00 mM, and 0.06-10.00 mM, respectively. The blood glucose level of normal person ranged from 4 to 6 mM, so that the enzyme electrode with NPZ and without NPZ are suitable for use in the determination of the concentration of blood glucose. While the enzyme electrode with zeolite A has a smaller range so it is more suitable to use in the determination of glucose concentration in the foods or beverages. The enzyme electrode with NPZ and the enzyme electrode with zeolite A showed a good accuracy with relative error values were 3.84% and3.48%, respectively. Repeatability measurements also showed a good precission results with relative standard deviation values (%RSD) for the enzyme electrode with NPZ and enzyme electrode with zeolite A were 3.83% and 3.16%, respectively. By combining two immobilization techniques, physical adsorption on zeolite and entrapment on carbon paste, high enzymatic activity, good accuracy, and repeatability was attained. The enzyme electrode with NPZ and the enzyme electrode with zeolite A demonstrated a good electrochemical response toward glucose, allowing it to detect blood glucose levels and glucose levels in foods and beverages.
Keyword: glucose biosensor, immobilization, zeolite