1,720,962 research outputs found
DISTRIBUSI LOGAM BERAT PADA SEDIMEN DI PERAIRAN MUARA DAN LAUT PROPINSI JAMBI
Full text linkKeberadaan logam berat pada sedimen dapat menjadi polutan apabila konsentrasinya melebihi ambang batas yang ditentukan. Tujuan dari penelitian ini untuk mengkaji konsentrasi logam berat pada sedimen di perairan sungai dan laut di Propinsi Jambi. Tiga sampel sedimen di perairan sungai dan sepuluh sampel sedimen di perairan laut diambil untuk dilakukan analisis laboratorium. Analisis logam berat yang dilakukan di laboratorium meliputi Arsenic (As), Cadmium (Cd), Total Chromium (Cr), Nickel (Ni), Mercury (Hg), Selenium (Se), Zinc (Zn), Copper (Cu), Lead (Pb) dan Cobalt (Co). Hasil analisis laboratorium menunjukkan bahwa Arsenic, Cadmium, Mercury dan Selenium tidak terdeteksi pada sedimen di perairan laut dan sungai. Daerah penelitian terdeteksi tercemar oleh Cobalt (Co) baik di muara sungai dengan konsentrasi 23-25 mg/kg maupun di peraian laut dengan konsentrasi 21-31 mg/kg. Sementara area dekat dengan muara sungai tercemar Cuprum (Cu) dengan konsentrasi 68 mg/kg dan sedikit tercemar Nickel (Ni) dengan konsentrasi 14 mg/kg, dan Chromium (Cr) dengan konsentrasi 19 mg/kg. [Title : DISTRIBUTION OF HEAVY METAL IN SEDIMENT AT COASTAL AREA JAMBI PROVINCE] The presence of heavy metals in sediments can be a pollutant when its concentration exceeds a specified threshold. The objective of this study is to analyze the concentration of heavy metals in the river and marine sediments in the Jambi Province. Three samples of river sediments and ten samples of marine sediments was taken for laboratory analysis. Analysis of heavy metals were conducted in the laboratory include arsenic (As), Cadmium (Cd), Total Chromium (Cr), Nickel (Ni), Mercury (Hg), Selenium (Se), Zinc (Zn), Copper (Cu), Lead (Pb) and Cobalt (Co). Result of laboratory analysis indicates that Arsenic, Cadmium, Mercury and Selenium were not detected in sediments in the sea water and the mouth of rivers. Research area detected tainted by Cobalt (Co) with concentration 23-25 mg/kg in area near the mouth of the river and 23-25 mg/kg in sea water. While the area near the mouth of the river highly polluted by Cuprum (Cu) with concentration 68 mg/kg and slightly polluted by Nickel (Ni) with concentration 14 mg/kg and Chromium (Cr) with concentration 19 mg/kg.
ANALISIS KANAL-KANAL LANDSAT 8 OLI UNTUK PEMETAAN BATIMETRI DI SEKITAR PULAU PUTRI, KOTA BATAM
No full textBatimetri mempunyai peran penting dalam perencanaan wilayah pesisir sehingga pemetaan batimetri dangkal sangat diperlukan. Penginderaan jauh merupakan salah satu metode yang efisien, mudah dan murah untuk pemetaan tersebut. Penelitian ini bertujuan untuk menganalisis kanal-kanal terbaik pada Landsat 8 OLI untuk memetakan batimetri dan kedalaman optimum yang dapat dipetakan sehingga dapat digunakan sebagai rujukan dalam memanfaatkan data penginderaan jauh untuk pemetaan tersebut. Lokasi kajian dilakukan di pulau Putri, Kota Batam, Provinsi Kepulauan Riau. Analisis regresi linear menunjukkan kanal tunggal terbaik untuk pemetaan batimetri adalah kanal hijau (kanal 3), diikuti oleh kanal merah (kanal 4) dan kanal inframerah dekat (kanal 5). Namun pemetaan batimetri dengan kombinasi kanal menghasilkan koefisien determinasi yang lebih baik. Analisis best subset menunjukkan pemetaan batimetri pada kedalaman 0 – 20 m menggunakan kanal 2, 3, 5, dan 6 dengan koefisien determinasi (R2) 85,4%; kedalaman 0 – 25 m menggunakan kanal 1, 3, 5, 6, dan 7 dengan R2 75%; dan pemetaan kedalaman 0 – 50 m menggunakan kanal 1, 3, dan 4 dengan R2 49,1%. Hasil pemetaan batimetri menggunakan Landsat 8 OLI secara umum lebih efektif dan mempunyai akurasi tinggi pada kedalaman 0 – 20 m dan semakin berkurang kemampuannya pada kondisi perairan yang semakin dalam.Kata kunci: Batimetri, Landsat 8 OLI, kanal, algoritma. Bathymetry has an important role in planning coastal areas so that mapping of shallow bathymetry is needed. Remote sensing is one of the efficient, easy and inexpensive methods for mapping. This study aims to analyze the best channels in Landsat 8 OLI for mapping bathymetry and optimum depth that can be mapped so that it can be used as a reference in utilizing remote sensing data for mapping. The location of the study was conducted on the Putri island, Batam City, Riau Islands Province. Linear regression analysis shows the best single channel for bathymetry mapping is the green channel (channel 3), followed by the red channel (channel 4) and the near infrared channel (channel 5). But bathymetry mapping with channel combinations produces a better coefficient of determination. Best subset analysis shows bathymetry mapping at depths of 0-20 m using channels 2, 3, 5, and 6 with a coefficient of determination (R2) of 85.4%; depth of 0 - 25 m using channels 1, 3, 5, 6, and 7 with R2 75%; and mapping depth 0 - 50 m using channels 1, 3, and 4 with R2 49.1%. The results of bathymetry mapping using Landsat 8 OLI are generally more effective and have a high accuracy at a depth of 0-20 m and are increasingly reduced in conditions of deeper water conditions. Keywords: Bathymetry, Landsat 8 OLI, Band, Algorithm
Optimalisasi data Landsat 7 ETM(plus) dan SRTM untuk revisi peta geologi lembar Bojonegoro
No full textESTIMASI PERUBAHAN STOK KARBON DAN SERAPAN CO2 PADA EKOSISTEM MANGROVE TAHUN 2019 – 2024 DI KARAWANG MENGGUNAKAN SENTINEL 2A
Full text linkGas rumah kaca mengakibatkan perubahan pola curah hujan, peningkatan frekuensi badai, naiknya permukaan air laut,menurunnya salinitas, dan meningkatnya sedimentasi di wilayah pesisir dan laut. Mangrove sebagai ekossitem pesisir mempunyai peran penting dalam mengurangi dampak gas rumah kaca melalui penyerapan karbon di lingkungannya yang lebih baik dari hutan biasa. Penelitian ini bertujuan untuk mengetahui estimasi kerapatan vegetasi, biomassa atas tanah, biomassa bawah tanah, total akumulasi biomassa, stok karbon total, serta jumlah serapan CO2 pada ekosistem mangrove di Kecamatan Cilebar dan Tempuran, Karawang. Pada penelitian ini dilakukan analisis terintegrasi melalui pengolahan data Sentinel 2A, survei lapangan dan perhitungan estimasi stok dan serapan karbon menggunakan rumus allometrik . Hasil penelitian menunjukkan estimasi stok karbon mangrove pada tahun 2019 dengan nilai 38,912 – 48,64 pada area seluas 121,81 Ha. Pada tahun 2021 stok karbon mangrove bernilai 41,58 – 51,975 seluas 148,81 Ha Pada tahun 2024 stok karbon mangrove bernilai 45,032 – 56,29 seluas 179,47 Ha. Hasil analisis lanjutan menunjukkan serapan CO2 di Kecamatan Cilebar dan Tempuran, Karawang pada tahun 2019 bernilai 127,08- 169,46 dengan seluas 121,81 Ha Pada tahun 2021 serapan CO2 bernilai 132,395 – 176,52 seluas 148,81 Ha Pada tahun 2024 serapan CO2 bernilai 137,04 – 182,72 seluas 179,47 Ha Penambahan serapan karbon terjadi karena keberhasilan rehabilitasi, pencegahan perusakan, serta lingkungan yang cocok untuk pertumbuhan mangrove.
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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