Karakteristik Kimiawi dan Kesuburan Perairan Teluk Pelabuhan Ratu pada Musim Barat dan Timur

Hasil penelitian pada periode musim barat (Desember, 1993) maupun timur (Juli, 1994) memperlihatkan kadar zat hara (NO3-N, NH4-N, PO4-P) yang relatif rendah bagi kebutuhan optimum proses fotosintesis fitoplankton. Unsur hara SiO2 terlarut pada musim barat, baik di perairan permukaan (37.56 - 151.68 mg SiO2/l) maupun pada kedalaman 25 m (3.97 - 39.19 mg SiO2/l) jauh berada di atas rata-rata normal 2.0 mg SiO2/l. Lain halnya pada musim timur, kadar SiO2 tercatat rendah yaitu 0.135 - 0.995 mg SiO2/l (perairan permukaan) dan 0.132 - 0.218 mg SiO2/l (kedalaman 25 m). Keberadaan unsur hara di perairan teluk selain dipengaruhi aktivitas fotosintesis juga dipengaruhi masukan dari sistem sungai yang bermuara di teluk (elemen alogenik) antara lain berupa pengaruh tingginya padatan tersuspensi (79 - 660 mg/l) yang terbawa sungai terutama pada musim barat. Penyebaran vertikal (hingga kedalaman 25 m) unsur hara pada kedua musim memperlihatkan kecenderungan menurun, terutama silikat, fosfat dan nitrat pada musim barat. Kadar unsurhara yang relatif lebih rendah pada kedalaman 25 m diikuti oleh kelimpahan organisme plankton yang lebih rendah dibandingkan dengan yang terdapat di perairan permukaan. Pada musim barat, produktivitas atau kesuburan perairan teluk, dinilai dari kelimpahan organisme plankton dan bentos, tergolong rendah sampai sedang. Berbeda dengan musim timur, produktivitas perairannya relatif tinggi yang dicirikan oleh kelimpahan plankton yang tinggi

Optimization of Fin Geometry for Condensation on Integral Fin Tubes

This paper reports an optimization aimed at verifying the accuracy of a semi-empirical condensation heat transfer model in calculating the enhancement ratio of a rectangular- finned tube. Three condensing fluids (ethylene glycol, refrigerant-R113 and steam) and three tube materials (copper, brass and bronze) were used to evaluate the response of the model at different fluid properties. Optimum tube geometries (diameter, fin thickness, height and spacing) were calculated and later compared with those geometries of a real condenser. The verification was achieved by comparing the condensation results of the model based on numerical calculations using Excel spread sheet with an established experimental data from the measurements of condensation heat transfer. The optimization results showed that the model accurately predicted the observed trends in the experimental data for the condensing fluids of steam, R113 and ethylene glycol. Condensation of refrigerant-R113 on copper tube material was found to be the best predicted model. Calculated optimum fin spacing for steam as a condensing fluid corresponded reasonably to those of a real condenser. Optimum fin spacing increased with increased surface tension

Perbedaan Prestasi Belajar Kosakata Bahasa Lampung antara Penggunaan Pembelajaran Deep Dialogue/critical Thinking

The objectives of this research were to analyze (1) the interaction between used learning models and learning interest to vocabulary learning achievement of Lampungnese Language (VLAL); (2) the differences of VLAL between using Deep Dialogue/Critical Thinking (DD/CT) in Lampungnese language and DD/CT in Indonesian language; (3) the differences of VLAL on students using DD/CT in Lampungnese language and DD/CT in Indonesian language between those students with high interest and low interest learning.Population was Indonesian language literature students of Faculty of Teacher Training and Education (FTTE).The results showed that (1) there was an interaction between Lampungnese language learning interest and used learning model to VLAL; (2) students’ VLALs who used DD/CT in Lampungnese language were higher than those in Indonesian language;(3) students’ VLALs with high interest in DD/CT learning with Lampungnese language were higher than those with Indonesian language.Penelitian ini bertujuan menganalisis (1) interaksi pembelajaran yang digunakan dan minat belajar terhadap prestasi belajar kosakata bahasa Lampung (PBKBL),(2) perbedaan PBKBL yang dalam pembelajarannya menggunakan Deep Dialogue/Critical Thinking (DD/CT) berbahasa Lampung dan berbahasa Indonesia,dan (3)perbedaan PBKBL yang dalam pembelajarannya menggunakan DD/CT berbahasa Lampung dan berbahasa Indonesia antara yang memiliki minat belajar tinggi dan yang memiliki minat belajar rendah.Populasi adalah seluruh mahasiswa Program S-1 Bahasa dan Sastra Indonesia FKIP Unila Angkatan 2010. Hasil penelitian menunjukkan: (1) Ada interaksi minat belajar bahasa Lampung dan pembelajaran yang digunakan terhadap PBKBL.(2) PBKBL mahasiswa yang dalam pembelajarannya menggunakan DD/CT berbahasa Lampung lebih tinggi daripada PBKBL mahasiswa yang dalam pembelajarannya menggunakan DD/CT berbahasa Indonesia.(3) PBKBL mahasiswa yang memiliki minat tinggi dalam pembelajaran DD/CT berbahasa Lampung lebih tinggi daripada PBKBL mahasiswa yang memiliki minat tinggi dalam pembelajaran DD/CT berbahasa Indonesi

Pengaruh Suhu Dan Salinitas Terhadap Respon Fisiologi Larva Tiram Mutiara Pinctada Maxima (Jameson)

PENDAHULUANPinctada maxima adalah spesiesakuakultur yang mempunyai nilaiekonomi tinggi (Taylor et al. 1997). Dipasaran Internasional, mutiara yangdiproduksi sering kali disebut dengannama “South Sea Pearl”. Indonesiatermasuk salah satu negara penghasilmutiara (South Sea Pearl) yang cukupdiskenal di pasaran dunia, sebagian besarproduksi South Sea Pearl yang dipasarkanberasal dari hasil budidaya (Anna2006). Produksi mutiara berbasisbudidaya merupakan aktivitas USAha yangmenguntungkan. Perkembangan USAhabudidaya mutiara saat ini sudah mengarahpada kegiatan industri yang terintegrasi(Fassler 1995).The Effect of Temperature and Salinity to The Physiological Respons on The Larvae ofPinctada maxima (Jameson). Energy budget is one of the most sensitive tools available forindividual assessing environmental changes like temperature and salinity, and also prerequisitefor individual growth and survival. The aim of this study is to obtained information on energybudget on routine metabolism, in different levels of temperature and salinity, and to know thelevels of optimum temperature and salinity. The research was used randomized block design,with three replications. The result showed that optimal temperature and salinity on P. maximalarvae was 28 oC and 32 – 34 ‰ (BE and BF). Energy budget to routine metabolism increasedwas attributed to increased temperature and salinity due to the optimal, than would be decreasedwhen temperature and salinity increased. The highest of energy budged for routine metabolismat treatment BF. Stage I: energy budged between 6.73 – 7.35 C g wet weight-1 hour-1 (28.18 –30.74 J g wet weight-1 hour-1); Stages II: 5.85 – 5.95 C g wet weight-1 hour-1 (24.48 – 24.90 J g wetweight-1 hour-1); Stages III: 4.73 – 4.80 C g wet weight-1 hour-1 (15.07– 19.58 J g wet weight-1hour-1). The highest survival rate of larvae was by treatment BF, but has not higher significant(P e” 0.05) with BE, stage I: survival rate between 87.75 – 87.92 %; Stage II: 81.91 – 82.39 % andstage III: 76.72 – 77.26 %. The best of relative growth length of larvae by treatment BF and notsignificant (P e” 0.05) with BE, at stage I: 29.78 x 17.93 ?m – 30.57 x 18.43 ?m (AP x DV); stageII: 57.62 x 46.73 ?m – 58.13 x 47.33 ?m and stage III: 80.32 x 69.29 ?m – 80.88 x 69.62 ?m. Thequickest time of plantigrade stages have found by treatment BF (day 19.50) and hasn'tsignificant (P > 0.05) with BE (day 20.85)