1,720,985 research outputs found
EUTROFIKASI NITROGEN DAN FOSFOR SERTA PENGENDALIANNYA DENGAN PERIKANAN DI WADUK SERMO (Eutrophication by Nitrogen and Phosphorous and Its Control Using Fisheries in Sermo Reservoir)
Full text linkABSTRAK
Penelitian mengenai konsentrasi nitrogen (N) dan fosfor (P) dilakukan dengan tujuan untuk mengevaluasi tingkat eutrofikasi dan pencemaran air, menghitung neraca N total dan P total serta melakukan pengendaliannya menggunakan perikanan. Penelitian dilakukan menggunakan metode survai, yaitu melakukan pengambilan sampel dan pengamatan air secara purposive. Pengambilan sampel air di daerah waduk (hulu, tengah dan hilir waduk) dan daerah sungai (sungai masuk dan sungai keluar). Di daerah waduk diamati pada jeluk air: 0 m, 2 m, 4 m dan dasar. Pengambilan sampel air dilakukan tiap bulan, mulai Juni 2006 sampai Mei 2007. Vanabel penelitian meliputi: amonia, amonium, nitrit, nitrat dan fosfat; N total dan P total, suhu air, kekeruhan, TDS, TSS, O, terlarut, pH, CO, bebas, alkalinitas dan plankton. Eutrofikasi air oleh N dan P dianalisis secara diskriptif dan tingkat pencemaran air dihitung menggunakan Indeks Pencemaran (lP) yang disyaratkan PP RI Nomor 82. Neraca N total dan P total dihitung dengan input-output, sedangkan pengendaliannya menggunakan metode simulasi. Hasil penelitian menunjukkan bahwa eutrofikasi pada tingkat eutrofik sampai hipereutrofik, pencemaran air masih tergolong ringan di daerah budidaya ikan dan waktu konsentrasi P maksimum; budidaya ikan menggunakan KJA jaring ganda, penebaran dan pemanenan ikan di luar KJA dapat mengurangi residu dan beban N total dan P total.
ABSTRACT
The research of nitrogen (N) and phosphorus (P) in Sermo reservoir aimed to evaluate water eutrophication and pollution, to calculate N total and P total budget and to control its concentration using fisheries. The research was conducted by direct observation and measurement on water samples taken from inflow and outflow rivers, upstream, middle and downstream areas of reservoir. The samples is reservoir were taken at water depth: 0-2,4 m and the bottom. Observation was done monthly from June 2006 up to May 2007. the variables were ammonia, ammonium, nitrite, nitrate and phosphate concentration, N total and P Total, water temperature, transparency, turbidity, total dissolved and suspended solids, dissolved O2, alkalinity and plankton. The research conclude that eutrophication level varies from eutrophic to hypereutrophic, light pollution was found in fish culture area and when the highest concentration of P, controlling of N and P by fish culture using double nets, fish stocking and harvesting in outside net cage may eliminate residue and decrease loading of N total and P total in the wate
Analisis rasio keuangan hubungannya dengan kemampulabaan pada PT Primissima
No full textHasil analisis melalui pendekatan regresi berganda terbukti bahwa terdapat hubungan yang signifikan antara profitabilitas dengan rasio keuangan. Debt to equity ratio berdampak negatif terhadap tingkat rentabilitas usaha Pt Primissima, sedangkan current ratio, inventory turnover, dan account receivable turnover memiliki dampak yang positif terhadap tingkat rentabilitas perusahaan. Nilai koefisien determinasi dari model regresi yang dibentuk sebesar 0.828 menunjukkan bahwa penggunaan beberapa rasio keuangan sebagai variabel bebas dalam model regresi memberikan gambaran bahwa 82.8% variabel terikat (ROI) dipengaruhi oleh variabel bebas tersebut. Dari uji t dan uji f diketahui bahwa semua variabel bebas dan dari uji Durbin Watson menunjukkan bahwa tidak terjadi serial auto korelasi positif atau negatif antar sampel dalam satu variabel dalam model regresi yang dibentuk
STUDI KELAYAKAN PENGEMBANGAN TEKNIK BUDIDAYA TAMBAK DI PROYEK IRIGASI SADANG KABUPATEN POLMAS, SULAWESI SELATAN
No full textAplikasi Electrical Resistivity Tomography (ERT) untuk Sistem Grounding: Studi Kasus di Pesisir Bandar Lampung
Full text linkElectrical resistivity tomography telah digunakan untuk membantu memetakan zona konduktif sebagai tapak penempatan electrode penangkal petir di Pesisir Bandar Lampung. Terdapat tiga lintasan ERT menggunakan konfigurasi Wenner-Schlumberger, panjang lintasan 200 m dan spasi antar electrode 6 m. Profil bawah permukaan memperlihatkan kemiripan tersusun oleh dua lapisan. Llapisan konduktif dengan kedalaman 0 – 15 m, menutup lapisan resistif di bawahnya. Zona konduktif dengan resistivitas < 7 Ω-m berupa lensa-lensa sebagai air tanah dangkal yang terpapar oleh air laut. Pengayaan unsur khususnya Na, Cl, dan Mg, telah menjadikan air tanah dangkal berperan sebagai konduktor dan memenuhi spesifikasi untuk penempatan electrode system penangkal petir. Kata kunci: ERT; grounding; pesisir bandar lampung DOI: http://dx.doi.org/10.23960/jpg.v11.i2.2850
Analisis Penurunan Muka Tanah dengan Small Baseline Subset Differential SAR Interferograms di Kota Bandar Lampung
Full text linkBandar Lampung is one of the cities in Indonesia, which has a potential to land subsidence due to the extraction of ground water, mining, land conversion, and geological conditions. For that reason, carried out the study of land subsidence with SBAS technique, due to the very lack of information about the symptoms of land subsidence in Bandar Lampung. In this study, 15 SAR data in 2006 to 2011 used and then combined to produce 40 interferogram then inverted resulting in a time-series deformation and deformation speed average. Velocity precision obtained with SBAS technique is highly dependent on the type of land cover in the study area, but it is known that the average of land subsidence in Bandar Lampung is about 0.06 mm/year, which is considered quite stable due to the geological structure that does not allow for the occurrence of massive consolidation process. Several areas have indications of subsidence 5 mm/year are suspected to be caused by tectonic activity and human activity (industrial, mining, extraction of groundwater, and land conversion), which then has implications for structural damage to buildings, flooding in coastal areas, and landslides in hilly areas
PEMODELAN DAN ANALISA STRUKTUR BAWAH PERMUKAAN DAERAH PROSPEK PANASBUMI KEPAHIANG BERDASARKAN METODE GAYABERAT
Full text linkResearch has been conducted in Kepahiang area using gravity data with the aim of identify faults based on analysis of the Second Vertical Derivative (SVD) and interpreting structure sub-surface of the based on 3D inverse modelling from Bouguer anomaly and residual anomaly. The research area have an Bouguer anomaly between 38 mGal - 74 mGal, where the high Bouguer anomaly value has a value range of 63,2 mGal - 74 mGal located in the southwest direction of the research area. Whereas the low Bouguer anomaly value has a range of values 38 mGal - 47 mGal located in the north of the research area. To know the existence of fault structure in research area, conducted filtering Second Vertical Derivative (SVD) on the map Bouguer anomaly, regional and residual. The structure faulting is shown with contour of zero and between the contours of high and low. From the analysis of SVD complete anomaly Bouguer and SVD residual anomaly there are 8 (eight) faulting, while from SVD regional anomaly there are 4 (four) fault. 3D inversion modeling of the residual anomaly was done to prove the existence of the fault analyzed based on filtering Second Vertical Derivative (SVD). Based on the results of inversion 3D residual anomaly been gained one (1) reservoir in a northern direction research area and two (2) in the direction of west the research area by a contrast the density of -0,0719356 gr/cc until -0,236053 gr/cc with a depth of 0 meters up to 4.705 meters
APLIKASI METODE GEOLISTRIK RESISTIVITAS KONFIGURASI WENNER- SCHLUMBERGER UNTUK MENGIDENTIFIKASI LITOLOGI BATUAN BAWAH PERMUKAAN DAN FLUIDA PANAS BUMI WAY RATAI DI AREA MANIFESTASI PADOK DI KECAMATAN PADANG CERMIN KABUPATEN PESAWARAN PROVINSI LAMPUNG
Full text linkResearch area is located in Padang Cermin Sun-District, Pesawaran Regency, Lampung Province. Manifestation in research area is hot water pool with surface temperatures reach 900C. Data acquisition has been done by Wenner-Schlumberger configuration with 5 acquisition line. Line 1, line 4 and line 5 have 280 meters length. Line 2 have 240 meters length and line 3 have 320 meters length with a spacing of each electrodes in each lines is every 5 meters. The objective of this research are (1)examining the geochemical contaminant and fluid types, (2)identifies the geothermal fluid based on 2D and 3D resistivity data analysis, also (3)identifies the layer of rock in Padok manifestation area based on 2D and 3D subsurface resistivity section. Subsurface lithology in research area generally divides into 4 parts. Which is hot water fluid with mean resistivity value between 1 Ωm into 3 Ωm and based on geochemistry data the fluid type is chloride water; surface sediment with resistivity value between 6 Ωm into 50 Ωm and identified as swamp sediment and alluvium sediment divides into gravels, pebbles, sands, clay and peat; Gravels, pebbles, sands, clay and peat with resistivity value between 50 Ωm into 100 Ωm; and igneous rock (andesite-basalt) with resistivity value more than 100 Ωm
INTERPRETASI SISTEM PANAS BUMI SUWAWA BERDASARKAN DATA GAYA BERAT
Full text linkThe research of gravity on Suwawa Sub-District geothermal is done for the purposes to determine fault structure using Second Vertical Derivative (SVD) technique, create a 2D subsurface model and 3D tentative model using regional anomaly data, and interpreting Suwawa geothermal system. Data processing is done in the research include: drift correction, terrain correction, free air correction, complete Bouguer anomaly, spectral analysis, SVD analysis, 2D modeling and 3D inversion modeling and tentative model. The research results showed that the research area has low Bouguer anomaly with a range of 75.8 to 79.5 mGal values in the West and Southeast, while high anomaly with a range of 90.9 to 111.2 mGal values in the Northern and Southern, there is correlation of fault based on SVD analysis with geological fault that indicate the presence of Libungo hot springs, the inversion results indicate the presence of low density (ρ = 1.8 g/cc) which is an alluvial rocks and high density (ρ = 2.9 g/cc) which is Andesite Lava rocks, 3D tentative modeling indicate the presence of reservoir is at a depth of 2 km from the ground surface. Based on the model created, Cap Rock is located on Andesite Lava rocks with ρ = 2.9 g/cc at a depth of 1200 m and Heat Source located at a depth of 2000 m
ROCK FORMATION AND SITE CLASS IN BANDAR LAMPUNG
Full text linkSoil characteristics are important impact for the scale of damage caused by earthquake vibrations. The impact caused by an earthquake in a location depends on the shear wave velocity (Vs). The study examined the effect of sedimentary rock formations on shear wave velocity and site class based on SPT tests in two rock formations in Bandar Lampung. The value of Vs, Vs30 and site class is determined based on the N-SPT value. Older rock formations of Quaternary age, have produced compaction at a shallow depth of 2 m from the surface, with Vs30 360 m/s and site class C. While the formation is younger, compactions are formed at a depth of 20 m, Vs30 200 m/s and site class D
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