DISTRIBUTION OF NATURAL AND ANTHROPOGENIC RADIONUCLIDES IN SURFICIAL SEDIMENTS OF JAKARTA

The concentration and distribution of natural and anthropogenic radionuclide in surficial sediments of Jakarta Bay were investigated with the aim of evaluating its level and environmental radioactivity. Sediments were sampled in 30 locations using Smith-McIntyre Grab sampler. Sediments were dried, homogenized and sealed for 1 month for equilibration and for the detection, analysis and data acquisition, a high purity germanium (HPGe) detector coupled with a high resolution multichannel analyzer (MCA) was used. Additionally, the grain sizes were analyzed by means of hydrometer. The result shows that the specific activity of 238U, 226Ra, 232Th, 40K and 137Cs range from 6.71±1.01 Bq/kg to 28.63±4.29 Bq/kg, 6.46±0.97 Bq/kg to 28.21±4.23 Bq/kg, 16.62±2.49 Bq/kg to 40.46±6.07 Bq/kg, 115.80±12.16 Bq/kg to358.69±30.49 Bq/kg, and 0.03±0.01 Bq/kg to 1.99±0.34 Bq/kg with the average value are 12.83±2.11 Bq/kg, 12.03±1.98 Bq/kg, 26.55±4.36 Bq/kg, 235.55±19.37 Bq/kg, and 0.77±0.13 Bq/g, respectively. It shows that the activity of radionuclides in the research area are in natural level and the variation may be influenced by the grain size distribution in the sample. The absorbed dose rate and radium equivalent of gamma radiation was estimated to be 32.06±7.72 nanoGrey/h and 68.14±11.20Bq/kg, respectively

GEOKRONOLOGI LOGAM BERAT TIMBAL (Pb) DAN CADMIUM (Cd) PADA SEDIMEN DI MUARA SUNGAI WAY BELAU PROVINSI LAMPUNG

Muara Sungai Way Belau merupakan daerah pemukiman dengan jumlah penduduk yangsangat padat. Muara Sungai Way Belau sebagai daerah yang dekat dengan tetripat wisata,lahan budidaya dan tambak serta sumber mata pencarian warga yang tinggal disekiiarMuara Sungai Way Belau menyebabkan daerah tersebut memiliki potensi peningkatanpencemaran lingkungan tenitama logam berat seperti Pb dan Cd. Penelitian ini bertujuanuntuk mengetahui konsentrasi logam berat dan mengkaji geokronologi yang terkandungpada sedimen di Muara Sungai Way Belau. Penelitian ini telah dilaksanakan bulan Juli2017. Penentuan lokasi sampling menggunakan metode purposive samplfng dun prosespengambilan sampel menggunakan alat gravity core. Analisis kandungan logam beraxmenggunakan bantuan ICP-OES dan digunakan data umur sedimen sebagai data sekunder.Konsentrasi logam berat Pb dari tahun 1878-1998 yaitu 0.699- 2,119 ppm dan logamberat Cd sebesar 0,080-0,120 ppm. Kenaikan kandungan logam berat Pb dari tahun 1878-1998 sebesar 203% dan logam berat Gd sebesar 50%

FLUKS DEPOSISI Zn DAN Cr DI MUARA CISADANE BERDASARKAN PROFIL 210Pb UNSUPPORTED DAN SIKLUS BANJIR 5 TAHUNAN

Pengukuran profil 210Pb unsupported dan logam berat Zn, Cr pada sedimen di Muara Cisadane telah dilakukan pada tahun 2002. Kedua sedimen core diambil masing-masing di Muara Tanjung Burung dan Muara Tiang Sampan. Profil 210Pb unsupported dapat digunakan untuk menghitung laju pengendapan dan untuk menghitung fluks deposisi Zn dan Cr berdasarkan siklus waktu 5 tahunan. Laju pengendapan sedimen kering di Muara Tanjung Burung adalah 4,142 gr/cm2/th, 2,518 gr/cm2/th dan 1,27 gr/cm2/th masing-masing untuk periode 1997- 2002, 1992-1997 dan 1987-1992. Laju pengendapan pada Muara Tiang Sampan sebesar 3,626 gr/cm2/th, 2,8 gr/cm2/th dan 1,41 gr/cm2/th masing-masing untuk periode 1997-2002, 1992-1997 dan 1987-1992. Fluks deposisi Zn : Cr di Muara Tanjung Burung adalah 4,867 gr/m2/th : 0,9 gr/m2/th, 3,515 gr/m2/th : 0,69 gr/m2/th dan 1,363 gr/m2/th : 0,2 gr/m2/th; masing-masing untuk periode 1997- 2002, 1992-1997 dan 1987-1992. Fluks deposisi Zn:Cr di Muara Tiang Sampan adalah 3,368 gr/m2/th : 0,703 gr/m2/th, 2,814 gr/m2/th : 0,574 gr/m2/th dan 1,593 gr/m2/th : 0,303 gr/m2/th; masing-masing untuk periode 1997- 2002, 1992-1997 dan 1987-1992

SEDIMENT ACCUMULATION RATES IN COASTAL AREA OF MURIA PENINSULA, CENTRAL JAVA, ELUCIDATED FROM ENVIRONMENTAL ISOTOPE 210Pb

ABSTRACTSEDIMENT ACCUMULATION RATES IN COASTAL AREA OF MURIA PENINSULA, CENTRAL JAVA, ELUCIDATED FROM ENVIRONMENTAL ISOTOPE 210Pb. Sediment accumulation rates was investigated based on the profiles and inventories of 210Pb and Constant Rate of Supply (CRS) model in sediment cores collected from the coastal area of Muria Peninsula. Sediment cores were collected using gravity corer. The derived sediment accumulation rates vary along the coastline and along the cores and appear to be higher in the eastern part than western part of the site; i.e, between 0.5 to 3.4 kg/m2.y on the eastern part, 0.3 to 3.1 kg/m2.y in the central and 0.5 to 2 kg/m2.y on the western part. Highly deposited sediment may relate to the change in the up-land as well as in the coastal area itself.Keywords: sediment rate, 210Pb, CRS model ABSTRAKLAJU AKUMULASI SEDIMEN DI AREA PESISIR SEMENANJUNG MURIA, JAWA TENGAH, DENGAN ELUSIDASI LINGKUNGAN ISOTOP 210Pb. Telah dilakukan investigasi laju akumulasi sedimen berdasarkan profil dan inventori dari 210Pb dan model Constant Rate of Supply (CRS) pada sedimen core yang diperoleh dari daerah pesisir Semenanjung Muria. Sedimen diambil menggunakan alat gavity core. Laju akumulasi sedimen yang diperoleh bervariasi sepanjang pesisir dan sepanjang core dan untuk laju tersebut lebih tinggi di sebelah timur dibandingkan dengan daerah sebelah barat, yaitu antara 0,5 hingga 3,4 kg/m2.tahun di sebelah timur, 0,3 hingga 3,1 kg/m2.tahun in bagian tengah dan 0,5 hingga 2 kg/m2.tahun di sebelah barat. Laju deposit sedimen yang tinggi kemungkinan disebabkan oleh perubahan di daerah daratan dan daerah pesisir tersebut.Kata kunci: laju sedimen, 210Pb, model CR

PENGATURAN KECEPATAN MOTOR INDUKSI TIGA FASA DENGAN TEKNIK ARTIFICIAL INTELEGENT BERBASIS VEKTOR KONTROL

ABSTRACT Three phase induction motor has a weakness in controlling the speed which depends only on the input frequency, but this can be reduce with inverter technology. Torque setting on an induction motor with low ripple and transient response form and good steady state is the main criteria of this controller design. First, using a PI controller to obtain these parameters, but with certain conditions. Gain can’t be increased outside the limit, so needed more better response. With the Artificial Intelligent techniques, this deficiency can be reduced. Once technique is using fuzzy logic in design of the controller or with PI controller. Elements of Fuzzy and PI controller for each of the overall aim to solve problems that happen, such as during start motor, no load and load conition. This method using the input of voltage and current on the close loop for calculating the rotor parameters. Controller in this method is designed for speed control which used in vector control for dynamic induction motor analysis. The final result which obtained from the model of fuzzy logic controllers and PI controllers are compared. It’s expected that with fuzzy logic and PI controller can improve and reduce the ripple in motor torque and stator currents. It’s also can simplfy the restrictions on the magnitude of the torque and current values in a specific range on some kind of disturbance. Keywords: PI - Fuzzy controller, Inverter, Induction Motor, Vector Control, Intelligent Artifica

Estimasi Laju Akumulasi Sedimen di Perairan Laut Jawa Menggunakan Unsupported Pb-210

Akumulasi sedimen di perairan Laut Jawa terjadi cukup cepat karena banyaknya masukan material sedimen dari wilayah sekitar. Sejauh ini belum ada penelitian yang memberikan estimasi laju akumulasi di bagian tengah Laut Jawa dengan menggunakan Pb-210 sebagai tracer. Penelitian ini bertujuan untuk menghitung estimasi laju akumulasi sedimen Laut Jawa dengan menggunakan profil unsupported Pb-210. Sedimen core diambil dari dua lokasi di perairan Laut Jawa (bagian barat dan timur) menggunakan multicore pada saat cruise kapal riset Geomarin 3, MAJAFLOX 2015, Pusat Penelitian dan Pengembangan Geologi Kelautan (P3GL), Bandung. Diperoleh panjang sedimen core untuk bagian barat dan timur berturut-turut adalah 35 cm dan 37 cm. Contoh sedimen dipotong dengan interval yaitu 2 cm pada kisaran kedalaman (0-10 cm), 4 cm (kedalaman 10-22 cm) dan 6 cm (kedalaman >22 cm). Analisis aktivitas Pb-210 dilakukan menggunakan detektor Passiveted Implanted Planar Silicon (PIPS) Alpha Spektrometer. Model Constant Rate of Supply (CRS) digunakan untuk menghitung laju akumulasi dan umur sedimen. Hasil menunjukkan laju akumulasi sedimen di bagian barat bervariasi antara 0,002-0,014 kg/m2/th dalam kurun waktu tahun 126 tahun dan di bagian timur bervariasi antara 0,002-0,020 kg/m2/thdalam kurun waktu 128 tahun. Laju akumulasi sedimen mulai mengalami peningkatan pada tahun 1950 dengan laju 0,005 kg/m2/thhingga saat ini mencapai 0,020 kg/m2/th

Estimasi Laju Deposisi Sedimen di Muara Gembong Sungai Citarum

Telah dilakukan perhitungan estimasi laju deposisi sedimen melalui teknik analisis Pb-210 menggunakan alat spektrometer alpha di muara Gembong sungai Citarum.Muara Gembong sungai Citarum mengalami pendangkalan yang menganggu aliran sungai ke laut. Pendangkalan yang terjadi diduga karena rusaknya daerah hulu sungai. Dengan mengetahui profil Pb-210 excess pada sampel sedimen muara dapat diestimasi laju deposisi sedimen. Sampel sedimen muara diambil di dua lokasi, masing-masing satu di sebelah kanan dan kiri muara dengan menggunakan paralon berdiameter dalam 3,7 cm denganmetode gravitasi. Sedimen yang diperoleh diperlakukan sebagai sedimen undisturbed yang disimpan dan dibekukan dengan es campur garam di lapangan, yang selanjutnya disimpan dalam freezer di laboratorium. Sedimen yang telah beku dipotong-potong dalam interval yang diinginkan dan dimulai dari sedimen paling dalam. Sedimen yang telah dipotong dikeringkan dalam oven pada suhu 60oC selama 72 jam, dilakukan perlakuan kimia, dideposisikan dalam plat tembaga murni, dan diukur aktivitas Pb-210 dengan alat spektrometer alpha. Penanggalan umur sedimen dilakukan dengan metode constant of the rate of supply (CRS). Melalui penanggalan umur ini, lebih lanjut diketahui laju deposisi sedimen tiap kurun waktu di kedua lokasi.Laju deposisi rata-rata bulk sedimen cenderung semakin tinggi dari tahun ke tahun, yaitu sebelum tahun 1976 berkisar 0,58 cm/th dan 0,14 cm/th; antara tahun 1976 s/d 1998 berkisar 0,82 cm/th dan 0,89 cm/tahun;  antara 1999 s/d 2016 berkisar 1,28 cm/tahun dan 1,28 cm/tahun, masing-masing untuk lokasi I dan lokasi II

KANDUNGAN LOGAM ESENSIAL TEMBAGA (Cu) DI LINGKARAN TAHUN KARANG PORITES LUTEA DARI PERAIRAN CAGAR ALAM PULAU SEMPU MALANG

Sempu Island is a nature reserve that has fringing reef with percentage of living coral cover almost constant 37% from 2009 to 2016. Coral massive Porites lutea in this area has a growth rate about 1.09 cm/yr. in average and almost similar with others. Coral massive growth rate can be monitor through their skeletal annual banding. They have two type annual banding, low density for slow growth coral skeletal and high density for fast growth rate of coral skeletal. In this banding coral can record any environmental condition such as sea water temperature, tides and heavy metal. The aim of this research was to know the concentration of copper in Sempu Island Nature Reserve in the past used ICP-OES. The result showed that the Cu concentration in P. lutea skeletal band from 2009-2016 were: 5.213; 6.403; 5.825; 6.511; 6.132; 6.403; 6.467; 6.22 mg/kg. The coral skeletal can absorb the pollutant for hundred years, and it will give important information for palaeo environment that can used for climate modelling in the future

SEDIMENT ACCUMULATION PROFILE IN MANGROVE RESTORATION AREA OF LEMBAR BAY-LOMBOK ISLAND

Mangrove restoration is really needed for restoring its ecosystem functions, so that it could be able to support fisheries activity and to protect coastal by extreme weather. In addition, mangrove is able to accumulate sediment that important in protecting the coastal area from sea level rise. Therefore,  the aim of this study is to investigate sediment accumulation rate in mangrove area during post restoration. Sampling location were divided into three different stations based on estimated restoration ages, such as ≥ 15  years old (Station 1), 4 - 10 years old (Station 2) and 2 - 8 years old (Station 3). Sediment cores were carried out by inserting 7.6 cm diameter and 100 cm length of polyvinyl chloride pipes. Sedimentation rate is measured by using Pb-210 radionuclide analysis. The results show that the sediment accumulation rate in the last 20th years from all station ranges from 0.17 to 0.42 g/cm2/year. The highest accumulation rate is found at oldest year old station while the lowest accumulation rate is found at younger year old station of mangrove restoration area. Restoration process is clearly able to recover the mangrove’s role in trapping sediment in coastal region. Keywords: sediment accumulation, mangrove restoration, Lembar Bay-                   Lombok Island

SEDIMENT ACCUMULATION PROFILE IN MANGROVE RESTORATION AREA OF LEMBAR BAY-LOMBOK ISLAND

<p><em>Mangrove restoration is really needed for restoring its ecosystem functions, so that it could be able to support fisheries activity and to protect coastal by extreme weather. In addition, mangrove is able to accumulate sediment that important in protecting the coastal area from sea level rise. Therefore,  the aim of this study is to investigate sediment accumulation rate in mangrove area during post restoration</em><em>.</em><em> Sampling location were divided into three different stations based on estimated restoration ages, such as </em><em>≥ 15 </em><em> years old (Station 1), 4</em><em> </em><em>-</em><em> </em><em>10 years old (Station 2) and 2</em><em> </em><em>-</em><em> </em><em>8 years old (Station 3).</em><em> </em><em>Sediment cores </em><em>were </em><em>carried out</em><em> </em><em>by inserting 7.6 cm diameter</em><em> and 100 cm length of</em><em> </em><em>polyvinyl chloride</em><em> pipes. </em><em>Sedimentation rate is measured by using Pb-210 radionuclide analysis</em><em>. The result</em><em>s</em><em> </em><em>show that</em><em> </em><em>the sediment accumulation rate in the last 20^th years from all station </em><em>ranges from 0.17 to 0.42 g/cm²/year. The highest accumulation rate is found at oldest year old station while the lowest accumulation rate is found at younger year old station of mangrove restoration area. Restoration process is clearly able to recover the mangrove’s role in trapping sediment in coastal region.</em></p><p><em> </em></p><p><strong>Keywords</strong>:<em> sediment accumulation, mangrove restoration, Lembar Bay-                   </em><em>Lombok Island </em></p