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11.
Muhammad Ilyas Agus Sudaryanto Iwan Eka Setiawan Tomohiko Isobe Shin Takahashi 《Marine pollution bulletin》2011,62(1):89-98
A total of 33 surficial sediments from riverine and coastal waters from Surabaya, Indonesia were analyzed for PCBs and BFRs. Concentrations of PCBs (62 congeners), PBDEs (14 congeners) and HBCDs (3 isomers) varied from <DL-420, <DL-35 and <DL-5.4 ng g−1 dw, respectively. Higher concentrations of these compounds were found in riverine than coastal sediments. Their levels and distribution were influenced by proximity to the point sources and TOC. The predominant congeners were CB-153, -28, -138, -149, -180, -33 and BDE-209, -207, -206, -197, -196, -183, -99, -47 for PCBs and PBDEs, respectively, and γ-isomer for HBCDs. Debromination of BDE-209 might be taking place producing lower toxic congeners in sediment. Levels of PCBs in riverine sediments were comparable with some polluted areas worldwide, but PBDEs and HBCDs were lower. Hazard assessment of PCBs indicated possible toxic potential, particularly in areas close to point sources. 相似文献
12.
Komang Anggayana Basuki Rahmad H. H. Arie Naftali Agus Haris Widayat 《Journal of the Geological Society of India》2014,83(5):555-562
Samples of early Miocene Muara Wahau coal from three drill cores were investigated with respect to maceral composition. Huminite macerals are dominant in the coal, ranging from 73.3 to 88.0% (vol.) with an average value of 77.4% (vol.). Liptinite macerals account for lower amount, from 0.7 to 6.7 with an average value of 1.8% (vol.). Inertinite macerals vary from 4.3 to 34.0% (vol.), averaging at 15.3% (vol.). Some paleoenvironmental indices based on the maceral composition were determined. Groundwater index (GWI) and vegetation index (VI) were considered as indicators for hydrological regime and type of peat vegetation. Tissue preservation index (TPI) and gelification index (GI) were determined to indicate the degree of preservation and relative wetness of the peat forming conditions. The VI-GWI diagram suggest that the coal was developed from herbaceous plants in ombrotrophic type of peat. TPI-GI diagram shows that the preservation was low and the peat was relatively wet or limnic. However, ombrotrophic peat type have commonly been related to relatively drier or telmatic environments. It is therefore, interpreted that the limnic condition could occur in ombrotrophic peat type, as the water level was rising up during the development of a high moor peat. 相似文献
13.
Age determination of paleotsunami sediments around Lombok Island,Indonesia, and identification of their possible tsunamigenic earthquakes 
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下载免费PDF全文 Aswan Yahdi Zaim Yan Rizal I. Nyoman Sukanta Suci Dewi Anugrah Agus Tri Hascaryo Indra Gunawan Tatok Yatimantoro Weniza Hidayanti Purnomo Hawati Wahyu Dwijo Santoso Nurochim 《地震科学（英文版）》2017,30(2):107-113
Age determination of paleotsunami sediment from Lombok Island, Indonesia, and surrounding area has been carried out using the 210 Pb method in BATAN Jakarta. The basic theory of this method assumes that weathering of sediments, including paleotsunami sediments, will result in 210 Pb enrichment. The principle of this method is to calculate 210 Pb contents accumulation in a particular sedimentation interval from the surface to the deeper buried sediments. The results are then converted into age or depositional time in years ago unit. The dating results from the paleotsunami sediments of the Gawah Pudak(S8°46’2.91’’, E115°56’34.23’’) and Gili Trawangan areas(S8°21’1.38’’, E116°2’36.6’’) indicate the Gawah Pudak sediments were deposited 37 years ago(c. in 1977)and 22 years ago(c. in 1992). Three paleotsunami sediments from Gili Trawangan were deposited 149 years ago(c. in 1865), 117 years ago(c. in 1897) and 42 years ago(c. in 1972). These results are then compared to the available Indonesian earthquake catalogue data. This study reveals that paleotsunami sediments around Lombok Islands, from older to younger, were caused by the 1857 earthquake(epicentre in Bali Sea; M7; S8°00’09.45’’,E115°29’56.41’’), 1897 earthquake(epicentre in Flores Sea;M5.5; S6°47’59.62’’, E120°48’03.5’’ or Sulu Sea earthquake; M8.5; 70 km NW of Basilan Island), the 1975 earthquake(Nusa Tenggara; S10°6’16.61’’, E123°48’09.39’’), 1977 earthquake(in Waingapu, Sumba; M8.0;S11°5’39.34’’, E118°27’50.86’’) and the 1992 earthquake(Flores; M7.8; S8°28’52.11’’, E121°53’44.3’’). 相似文献
14.
Characteristics and variability of the Indonesian throughflow water at the outflow straits 总被引：1，自引：0，他引：1
Agus Atmadipoera Robert Molcard Gurvan Madec Susan Wijffels Janet Sprintall Ariane Koch-Larrouy Indra Jaya Agus Supangat 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(11):1942-1954
Property structure and variability of the Indonesian Throughflow Water in the major outflow straits (Lombok, Ombai and Timor) are revised from newly available data sets and output from a numerical model. Emphasis is put on the upper layers of the Indonesian Throughflow that impacts the heat and freshwater fluxes of the South Equatorial Current in the Indian Ocean. During the April–June monsoon transition the salinity maximum signature of the North Pacific thermocline water is strongly attenuated. This freshening of the thermocline layer is more intense in Ombai and is related to the supply of fresh near-surface Java Sea water that is drawn eastward by surface monsoon currents and subject to strong diapycnal mixing. The freshwater exits to the Indian Ocean first through Lombok Strait and later through Ombai and Timor, with an advective phase lag of between one and five months. Because of these phase lags, the fresher surface and thermocline water is found in the southeast Indian Ocean from the beginning of the monsoon transition period in April through until the end of the southeast monsoon in September, a much longer time period than previously estimated. 相似文献
15.
Taufiq Hidayat Achmad Munir Budi Dermawan Anton Timur Jaelani Stéphane Léon Dading Hadi Nugroho Andriyan Bayu Suksmono Putra Mahasena Premana Wardayanti Premadi Dhani Herdiwijaya Chatief Kunjaya Zadrach Ledoufij Dupe Budi Brahmantyo Denny Mandey Muhammad Yusuf Hesti Retno Tri Wulandari Falahuddin Arief Muhammad Irfan Agus Triono Puri Jatmiko Evan Irawan Akbar Hery Leo Sianturi Jehunias Leonidas Tanesib Ali Warsito Judhistira Aria Utama 《Experimental Astronomy》2014,37(1):85-108
We report the first measurements of radio frequency spectrum occupancy performed at sites aimed to host the future radio astronomy observatory in Indonesia. The survey is intended to obtain the radio frequency interference (RFI) environment in a spectral range from low frequency 10 MHz up to 8 GHz. The measurements permit the identification of the spectral occupancy over those selected sites in reference to the allocated radio spectrum in Indonesia. The sites are in close proximity to Australia, the future host of Square Kilometre Array (SKA) at low frequency. Therefore, the survey was deliberately made to approximately adhere the SKA protocol for RFI measurements, but with lower sensitivity. The RFI environment at Bosscha Observatory in Lembang was also measured for comparison. Within the sensitivity limit of the measurement equipment, it is found that a location called Fatumonas in the surrounding of Mount Timau in West Timor has very low level of RFI, with a total spectrum occupancy in this measured frequency range being about 1 %, mostly found at low frequency below 20 MHz. More detailed measurements as well as a strategy for a radio quiet zone must be implemented in the near future. 相似文献
16.
Hakim Saibi Essam Aboud Agus Setyawan Sachio Ehara Jun Nishijima 《Arabian Journal of Geosciences》2011,5(5):1047-1054
Mount Ungaran is a Quaternary volcano located in the province of Central Java, Indonesia. The study area was covered by a gravity survey in order to delineate the subsurface structure and its relation to the hot springs that are spread throughout the area. The gravity data were analyzed using gravity gradient interpretation techniques, such as the horizontal gradient and Euler deconvolution methods, and many faults were detected. The results of the present study suggest that the hot springs around Ungaran Volcano are structurally controlled and have depths ranging from 1 to 3 km. The results of the present study lead to an understanding of the relationships between the interpreted faults and the locations of hot springs and may aid in future geothermal exploration of the area. 相似文献
17.
Suzuki Takeshi Yoshie-Stark Yumiko Santoso Joko 《中国海洋大学学报(英文版)》2005,4(3):205-208
Seaweeds are known to hold substances of high nutritional value; they are the richest resources of minerals important to the biochemical reactions in the human body. Seaweeds also hold non-nutrient compounds like dietary fiber and polyphenols. However, there is not enough information on the mineral compounds of tropical seaweeds. Also we are interested in the antioxidant activities of seaweeds, especially those in the tropical area. In this study, Indonesian green, brown and red algae were used as experimental materials with their mineral components analyzed by using an atomic absorption spectrophotometer. The catechins and flavonoids of these seaweeds were extracted with methanol and analyzed by high performance liquid chromatography （HPLC） ; the anti-oxidant activities of these seaweeds were evaluated in a fish oil emulsion system. The mineral components of tropical seaweeds are dominated by calcium, potassium and sodium, as well as small amounts of copper, iron and zinc. A green alga usually contains epigallocatechin, gallocatechin, epigallocatechin gallate and catechin. However, catechin and its isomers are not found in some green and red algae. In the presence of a ferrous ion catalyst, all the methanol extracts from the seaweeds show significantly lower peroxide values of the emulsion than the control, and that of a green alga shows the strongest anti-oxidant extract of this alga, which is significantly different from activity. The highest chelation on ferrous ions is also found in the the other methanol extracts in both 3 and 24 h incubations. 相似文献
18.
Setianto Samingan Agus Yulian Firmana Arifin Snehasis Tripathy Tom Schanz 《Acta Geotechnica》2013,8(2):155-165
This paper presents results of an experimental work to determine a relationship between swelling pressure and suction of heavily compacted bentonite–sand mixtures. For comparison, tests were also carried out on heavily compacted bentonite specimens. A series of swelling pressure tests were performed using multi-step constant-volume method where suction of the specimens tested was reduced in a stepwise manner toward a zero value. The suction reduction was induced using vapor equilibrium and axis-translation techniques. It is shown that compacted specimens did not exhibit any collapse upon suction decrease and exhibited maximum swelling pressures at zero-equilibrium suction. The development of swelling pressure with decreasing suction of the specimens showed threshold suctions below which a further reduction in suction yields an increase in the swelling pressure of the same magnitude. The magnitude of threshold suction was found to be a function of bentonite content in compacted specimens. 相似文献
19.
Shujiang Li Zexun Wei R. Dwi Susanto Yaohua Zhu Agus Setiawan Tengfei Xu Bin Fan Teguh Agustiadi Mukti Trenggono Guohong Fang 《Journal of Oceanography》2018,74(5):541-547
Using velocity profiles observed by bottom-mounted ADCPs, we identified strong intraseasonal variability in the Sunda Strait throughflow. This intraseasonal variability, with typical periods of 20–40 days and the strongest energy occurring in the boreal spring, can reverse the Sunda Strait throughflow. Further analysis showed this intraseasonal variability to be closely related to local zonal wind and the sea level gradient along the strait. These observations confirm for the first time the existence of Kelvin-wave-like signals in the Sunda Strait, propagating from the equatorial Indian Ocean. This study also provides new insights into the effects of Kelvin waves on the Sunda Strait throughflow. 相似文献
20.
Groundwater exploration using integrated geophysics method in hard rock terrains in Mount Betung Western Bandar Lampung,Indonesia 下载免费PDF全文
下载免费PDF全文 The presence of hard rock in Mount Betung has caused the misalignment of the groundwater aquifers,and resulted in many drilling failures for groundwater.An integrated geophysics method using gravity survey and Geoelectric Vertical Electrical Soundings(VES)were conducted to study the effect of basement and hard rock on groundwater prospects.From the gravity method,38 mapping points were carried out randomly,with a distance of 1-2 km in-between.Meanwhile,from the geoelectric method,51 VES points were acquired at the foot of Mount Betung.The acquisition was conducted with a Schlumberger configuration with AB/2=1 m to 250 m.The results show the Bouguer Anomaly in the west is 50-68 mgal due to the presence of hard rock in Mount Betung.This anomaly responds to relatively shallow hard rocks near surface.Hard rocks composed of andesite and breccia normally present at the depth of 5-180 m during well construction.Resistivity isopach mapping from VES data(at AB/2=50 m,100 m,and 150 m)shows the dominant constituents of hard rock.Fractures in hard rock contribute to secondary porosity,which could be a prospect zone that transmit groundwater.This finding shows that the fractures are randomly scattered,causing several well failures that have been worked.Furthermore,the fractures in the hard rock at the foot of Mount Betung acts as conduits between recharge at Mount Betung and the aquifer in the Bandar Lampung Basin. 相似文献