Judul: Analisis komunitas artropoda predator penghuni lansekap persawahan di daerah Cianjur, Jawa Barat
Abstrak: Penelitian dilaksanakan di Kecamatan Ciranjang dan Bojongpicung, Kabupaten Cianjur, Jawa Barat. Pengambilan contoh artropoda berlangsung mulai bulan Juli 1997 hingga Oktober 1998. Penelitian bertujuan untuk. mengkaji struktur komunitas artropoda predator pada berbagai komponen lansekap persawahan dan mengkaji kemiripan komunitas predator pada masing-masing komponen lansekap tersebut. Predator pada tajuk diamati dengan D-vac, sedangkan predator yang aktif di permukaan tanah diamati dengan lubang jebakan. Perangkap berperekat digunakan untuk memantau pemencaran predator melalui udara. Artropoda yang tertangkap kemudian diidentifikasi di laboratorium. Keanekaragaman spesies predator dianalisis dengan Indeks Shannon, Pielou dan Berger-Parker dan kemiripan komunitas predator antar habitat didekati dengan Analisis Korespondensi. Secara kuantitatif, kemiripan juga dihitung dengan Koefisien Kemiripan Sorensen. Untuk mengetahui perbedaan kerapatan populasi...dst
Keyword: keanekaragaman hyati; interaksi biologi; pola migrasi

Judul: Kelimpahan Artropoda Predator Permukaan Tanah pada Tiga Ekosistem Pertanaman
Abstrak: Penelitian ini bertujuan untuk mengetahui kelimpahan artropoda predator permukaan tanah pada ekosistem pertanaman jagung, ubi jalar dan cabai di Kelurahan Situgede Kecamatan Bogor Barat, Kota Bogor. Lubang perangkap yang dipergunakan untuk mengambil artropoda predator permukaan tanah terbuat dari gelas plastik bekas air mineral bervolume 240 ml. Dalam satu buah lubang perangkap dimasukkan formalin 2% sebanyak 30 ml. Jumlah lubang perangkap pada masing-masing pertanaman 20 buah yang dipasang menyebar secara sistematis dengan jarak 5 m antar lubang perangkap. Perangkap dipasang selama 3 x 24 jam dengan interval satu minggu selama delapan minggu. Artropoda predator permukaan tanah yang berhasil ditangkap dihitung jumlahnya dan diidentifikasi di laboratorium serta diawetkan ke dalam botol film yang berisi alkohol 90%. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL). Kelimpahan total artropoda predator permukaan tanah pada pertanaman jagung berjumlah 1196 individu, sedangkan pada pertanaman ubi jalar dan cabai masing-masing berjumlah 532 dan 421 individu. Artropoda predator permukaan tanah yang dominan pada tiga ekosistem pertanaman adalah semut (Formicidae), kumbang tanah (Carabidae) dan laba-laba serigala (Lycosidae). Proporsi ketiga artropoda predator tersebut pada pertanaman jagung adalah 54.52%, 25.42%, dan 16.97%, sedangkan pada pertanaman ubi jalar masing-masing sebesar 66.92%, 19.36%, dan 13.16%, serta pada pertanaman cabai masing-masing sebesar 45.13%, 44.89% dan 6.89%. Perkembangan kelimpahan artropoda predator pada tiga ekosistem pertanaman dipengaruhi oleh serasah, sedangkan curah hujan dan Collembola tidak tampak jelas pengaruhnya. Berdasarkan data yang telah dianalisis secara statistik menunjukkan bahwa rata-rata kelimpahan total artropoda predator permukaan tanah pada pertanaman jagung tertinggi dan berbeda nyata bila dibandingkan dengan pertanaman ubi jalar dan cabai.
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Judul: Enhancement of photon absorbtion on BaxSr1-xTiO3 thin films semiconductor using photonic crystals.
Abstrak: In this research, has been conducted BaxSr1-xTiO3 (BST) thin films manufacturing for mole fraction x = 0.25, 0.35, 0.45, and 0.55; and concentration of 1 molar using chemical solution depositon (CSD) method. The materials, which are used in this research, are barium acetate [Ba(CH3COO)2, 99%], strontium acetate [Sr(CH3COO)2, 99%], titanium isopropoxide [Ti(C12O4H28), 97.999%], gallium trioxide [Ga2O3], 2-methoxyethanol [H3COOCH2CH2OH, 99%] and 1 x 1 cm of transparent conductive oxide (TCO) glass as substrate. Two BST thin films are made that for BST thin films which are doped by 10% galium (BGST) as p-type layer and pure BST solution as n-type. BST solution is made by reacting barium acetate [Ba(CH3COO)2, 99%], strontium acetate [Sr(CH3COO)2, 99%] and titanium isopropoxide [Ti(C12O4H28)] into 2-methoxyethanol solvent [H3COOCH2CH2OH, 99%] in accordance with mass gram for each x value. While, BGST solution is made in the same way as BST solution, plus adding gallium at 10% of the mass of BST. Once all materials are reacted, then vibrated using ultrasonic for 90 minutes, and followed by coating BGST / BST on the TCO substrate. Once the layer is formed, then annealed for 15 hours at temperature of 500 °C with increasing rate of 1.67 oC/minute. Characterizations of BST thin films with or without photonic crystals include the absorbance and transmittance in the visible light spectrum, as well as the electrical photoconductivity characterizations. From BST thin films without photonic crystals indicate that our thin films have light absorption area on almost the entire range of the visible light spectrum even to the infrared range with absorption value over than 67.6%, in addition, it can be seen that the maximum absorbance of BST thin films for all mole fractions lie in blue to green light spectrum region, 457 nm ≤ λ ≤ 570 nm and the minimum in yellow to red light spectrum region, 570 nm ≤ λ ≤ 678 nm. The largest absorbance is found at x = 0.25 with average absorbance value of 92.04% and maximum and minimum absorbance peaks at wavelength of 500.89 and 657.72 nm, respectively. At x = 0.35, average absorbance value decreased to 83.55% with maximum and minimum peaks at 505.73 and 613.68 nm, respectively. Then increased to 91.16% at x = 0.45 with maximum and minimum peaks at 506.04 and 618.56 nm, respectively. At x = 0.55, average absorbance value decreased to 80.12% with maximum and minimum peaks at 507.85 and 608.79 nm, respectively. Moreover, it can be seen that the addition of barium mole fraction leads to wider maximum absorbance or minimum transmittance peaks and narrower minimum absorbance or maximum transmittance peaks in the same range of the green and blue & red light spectrums, respectively. BST thin films with photonic crystals show increasing in absorption for all x values in the range of 3.04 into 13.33%. At x = 0.25, average absorbance percentage increased 3.96% from 92.4 into 95.68%, for x = 0.35 average percentage increased 7.07% into 89.45 from 83.55%. Furthermore, average absorbance of BST thin films at x = 0.45 increased 3.04% from 91.16 into 93.93% and x = 0.55 has
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