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Author

Andi Agus Nur

Other affiliations: Hasanuddin University
Bio: Andi Agus Nur is an academic researcher from Padjadjaran University. The author has contributed to research in topics: Geology & Regional Ocean Modeling System. The author has an hindex of 3, co-authored 18 publications receiving 26 citations. Previous affiliations of Andi Agus Nur include Hasanuddin University.

Papers
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Journal ArticleDOI
01 Jun 2018
TL;DR: In this article, the authors used the terrain following three-dimensional Regional Ocean Modeling System (ROMS) to simulate the dynamic process such as the changes of water mass in the Balikpapan Bay.
Abstract: Balikpapan Bay is located in the East Borneo Province of Borneo, Indonesia and directly connected to the Makassar Strait and also has very important role in determining the dynamics of ocean current, heat and freshwater content in the Makassar Strait. Numerical model has been used to simulate the dynamic process such as the changes of water mass in the Balikpapan Bay. We have used the terrain following three-dimensional Regional Ocean Modeling System (ROMS). Tides, river discharges, and atmospheric forcing (surface fields) have been used as generating forces for the model. The model has been simulated for three months from 1 October 2012 to 1 January 2013. The model has been validated by computing the RMSE, MAPE and Willmott's index of agreement (d) using water level observation at the sampling station in Semayang port, Balikpapan. The verification showed a good agreement between model prediction and field observation data with RMSE = 7.8 cm, MAPE = 14.3% and d = 0.995 (with a value of perfect agreement equals to 1.0). The results analysed using vertical profile of salinity and temperature from 22 sampling stations with 11 stations located at the inner part of Balikpapan Bay. While the other stations located outside the Balikpapan Bay were used to analyse watermass. Water circulation is mostly dominated by the forcing from tides. The model results showed that the outer part of Balikpapan Bay is saltier than the inner part of Balikpapan bay. The highest average temperature occurred along coastal areas with value ~31 °C. The distribution of vertical salt transport showed that the water masses tend to be stratified during neap tides and mixed during spring tides condition.

8 citations

Journal ArticleDOI
01 Sep 2020
TL;DR: In this paper, the authors investigate how electrical resistivity changes as electromagnetic waves penetrate deep into the subsurface of Lili-Sepporaki geothermal prospect, using Magnetotelluric data.
Abstract: The objective of this paper is to investigate how electrical resistivity changes as electromagnetic waves penetrate deep into the subsurface of Lili-Sepporaki geothermal prospect, using Magnetotelluric data. Lili Sepporaki is an andesitic-trachytic volcanic-rich area located in western Sulawesi-Indonesia. Magnetotelluric data was processed using SSMT2000 and MTEditor software programmes. Results show that resistivity of rocks generally increases with decreasing frequency, that is; less than 100 Ohm-m for frequencies greater than 100 Hertz; and fluctuates between 100 -1000 Ohm-m for frequency range 10.1 Hertz. Resistivity also increases with depth of penetration of electromagnetic waves. Weathering, hydrothermal alteration, and many times fluids increase the conductivity of rocks. A low resistivity anomaly is seen around the hot spring, northwards. Presence of fluids in an intensively fractured volcanic rock lowers its resistivity. In the future, another Magnetotelluric sounding should be carried with much more measurement stations followed by a three-dimensions interpretation.

4 citations

DOI
14 Aug 2017
TL;DR: In this paper, anisotropic Inverse Distance Weighted (IDW-Anisotropic) is used to measure the potential of ground water in Papua Papua Barat, in order to detect potensi air tanah.
Abstract: ABSTRAK Kabupaten Raja Ampat merupakan bagian dari Provinsi Papua Barat yang memiliki potensi sumber air tanah dengan deposit air tanah yang cukup besar. Namun hingga saat ini data mengenai potensi air tanah di Kabupaten Raja Ampat belum ada. Maka hal inilah yang mendasari untuk dilakukan penelitian mengenai potensi akuifer air tanah pada batuan sedimen tersier berdasarkan analisis data geolistrik. Penelitian ini dilakukan di Distrik Waisai Kota, Kabupaten Raja Ampat dengan tahapan kegiatan meliputi pengamatan geologi daerah penelitian, pengukuran geolistrik dengan konfigurasi Schlumberger, pengolahan data resistivitas 1D, pemodelan 2D dan 3D dengan metode Anisotropic Inverse-Distance Weighted (IDW-Anisotropic) dan Isokonturing resistivitas, analisis dan interpretasi data, validasi data, serta perhitungan potensi air tanah. Pengukuran geolistrik dilakukan sebanyak 11 (sebelas) titik ukur di lokasi sekitar Kelurahan Bankawir dan Perumahan 300, Distrik Waisai Kota, Kabupaten Raja Ampat, Provinsi Papua Barat yang terletak pada koordinat geografis 130,82 – 130,89 Bujur Timur dan 0,43 – 0,38 Lintang Selatan. Penelitian ini bersifat analisis untuk mengetahui bagaimana karakteristik akuifer dan potensi air tanah, baik dari data primer maupun data sekunder. Litologi di lokasi penelitian didominasi oleh adanya pasir yang berselang seling dengan lempung. Secara umum berdasarkan interpretasi dari nilai tahanan jenis 1D (sounding) dapat disimpulkan bahwa karakteristik akuifer yang berada di lokasi penyelidikan terdiri atas akuifer bebas dan akuifer tertekan. Diduga bahwa lapisan yang bertindak sebagai akuifer bebas adalah lapisan pasir, yang secara umum berada pada rentang kedalaman 1.27 – 10.00 meter dengan rentang ketebalan antara 3.59 – 5.81 meter dan rentang nilai resistivitas 1.13 - 14.90 Ωm. Sedangkan lapisan yang bertindak sebagai akuifer tertekan yaitu lapisan pasir yang secara umum berada pada rentang kedalaman 22.30 – 75.00 meter dengan rentang ketebalan antara 10.90 - 37.10 meter dan rentang nilai resistivitas 28.20 - 150 Ωm. Berdasarkan hasil perhitungan potensi air tanah pada akuifer bebas dari tiap segmen di Distrik Waisai Kota, Kabupaten Raja Ampat diketahui bahwa area yang memiliki potensi sumberdaya air tanah yang potensial terletak pada segmen 2, dengan nilai Q Max sebesar 0.000331 m3/sec atau 28.598,4 liter/hari. Kata Kunci: Potensi Air Tanah, Akuifer, Geolistrik, Isoresistivity ABSTRACT Raja Ampat Regency is part of West Papua Province which has a large groundwater deposit. Data on the potential of groundwater in Raja Ampat regency has not existed yet. So this is the basis for research on the potential groundwater on free aquifer based on geoelectric measurements. This research was conducted in Waisai Kota District, Raja Ampat Regency with activity as follow: geological observation of research area, geoelectric measurements with Schlumberger configuration, 1D resistivity data processing, 2D and 3D modeling with Anisotropic Inverse-Distance Weighted(IDW-Anisotropic) and Isoconturing resistivity, data analysis and interpretation, data validation, and ground water potential calculation. Geoelectric measurements were carried out at 11 (eleven) measuring points at the locations around Bankawir and Perumahan 300, Waisai Kota District, Raja Ampat Regency, West Papua Province , which located at 130.82 - 130.89 East and 0.43 - 0,38 South. This research is an analysis about the free aquifer characteristics and ground water potential, both from primary data and secondary data. Lithology at the study site is dominated byintermittent sand with clay. Based on the interpretation of the resistance value, it can be concluded that the aquifer characteristics at study site consist of free aquifer and distressing aquifer. It is presumed that the layer acting as a free aquifer is a layer of sand, which is generally indepth range from 1.27 to 10.00 meters with a thickness range between 3.59 - 5.81 meters and a resistivity range of 1.13 - 14.90 Ωm. The layer acting as a distressing aquifer is sand layer that generally located in the depth of 22.30 - 75.00 meters with thickness range between 10.90 - 37.10 meters and resistivity range 28.20 - 150 Ωm. Based from the result of ground water potential calculation from each segment in Waisai District, Raja Ampat District, it is known that the area wit h potential groundwater resource potential lies in segment 2, with the value of Q Max 0.000331 m3 / sec or 28,598.4 liters /day. Key Word: Ground Water Potential, Aquifer, Geoelectric, Isoresistivity

3 citations


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Journal Article
TL;DR: In this article, a new parameterization of oceanic boundary layer mixing is developed to accommodate some of this physics, including a scheme for determining the boundary layer depth h, where the turbulent contribution to the vertical shear of a bulk Richardson number is parameterized.
Abstract: If model parameterizations of unresolved physics, such as the variety of upper ocean mixing processes, are to hold over the large range of time and space scales of importance to climate, they must be strongly physically based. Observations, theories, and models of oceanic vertical mixing are surveyed. Two distinct regimes are identified: ocean mixing in the boundary layer near the surface under a variety of surface forcing conditions (stabilizing, destabilizing, and wind driven), and mixing in the ocean interior due to internal waves, shear instability, and double diffusion (arising from the different molecular diffusion rates of heat and salt). Mixing schemes commonly applied to the upper ocean are shown not to contain some potentially important boundary layer physics. Therefore a new parameterization of oceanic boundary layer mixing is developed to accommodate some of this physics. It includes a scheme for determining the boundary layer depth h, where the turbulent contribution to the vertical shear of a bulk Richardson number is parameterized. Expressions for diffusivity and nonlocal transport throughout the boundary layer are given. The diffusivity is formulated to agree with similarity theory of turbulence in the surface layer and is subject to the conditions that both it and its vertical gradient match the interior values at h. This nonlocal “K profile parameterization” (KPP) is then verified and compared to alternatives, including its atmospheric counterparts. Its most important feature is shown to be the capability of the boundary layer to penetrate well into a stable thermocline in both convective and wind-driven situations. The diffusivities of the aforementioned three interior mixing processes are modeled as constants, functions of a gradient Richardson number (a measure of the relative importance of stratification to destabilizing shear), and functions of the double-diffusion density ratio, Rρ. Oceanic simulations of convective penetration, wind deepening, and diurnal cycling are used to determine appropriate values for various model parameters as weak functions of vertical resolution. Annual cycle simulations at ocean weather station Papa for 1961 and 1969–1974 are used to test the complete suite of parameterizations. Model and observed temperatures at all depths are shown to agree very well into September, after which systematic advective cooling in the ocean produces expected differences. It is argued that this cooling and a steady salt advection into the model are needed to balance the net annual surface heating and freshwater input. With these advections, good multiyear simulations of temperature and salinity can be achieved. These results and KPP simulations of the diurnal cycle at the Long-Term Upper Ocean Study (LOTUS) site are compared with the results of other models. It is demonstrated that the KPP model exchanges properties between the mixed layer and thermocline in a manner consistent with observations, and at least as well or better than alternatives.

409 citations

Journal ArticleDOI
TL;DR: Antineoplastic effectiveness in human clinical trials and mechanism of anticancer action have been reported for Antrodia camphorata, Cordyceps sinensis, Coriolus versicolor, Ganoderma lucidum, Grifola frondosa, and Lentinula edodes.
Abstract: This article reviews mushrooms with anti-breast cancer activity. The mushrooms covered which are better known include the following: button mushroom Agaricus bisporus, Brazilian mushroom Agaricus blazei, Amauroderma rugosum, stout camphor fungus Antrodia camphorata, Jew’s ear (black) fungus or black wood ear fungus Auricularia auricula–judae, reishi mushroom or Lingzhi Ganoderma lucidum, Ganoderma sinense, maitake mushroom or sheep’s head mushroom Grifola frondosa, lion’s mane mushroom or monkey head mushroom Hericium erinaceum, brown beech mushroom Hypsizigus marmoreus, sulfur polypore mushroom Laetiporus sulphureus, Lentinula edodes (shiitake mushroom), Phellinus linteus (Japanese “meshimakobu,” Chinese “song gen,” Korean “sanghwang,” American “black hoof mushroom”), abalone mushroom Pleurotus abalonus, king oyster mushroom Pleurotus eryngii, oyster mushroom Pleurotus ostreatus, tuckahoe or Fu Ling Poria cocos, and split gill mushroom Schizophyllum commune. Antineoplastic effectiveness in human clinical trials and mechanism of anticancer action have been reported for Antrodia camphorata, Cordyceps sinensis, Coriolus versicolor, Ganoderma lucidum, Grifola frondosa, and Lentinula edodes.

54 citations

Journal ArticleDOI
TL;DR: In this paper, the authors test different methods used for assessing sediment yield indices to identify hotspots and rank sediment yield hotspots, including the assessment of the entropy weight of sediment cores.
Abstract: This paper aims to test different methods used for assessing sediment yield indices to identify hotspots and rank sediment yield hotspots. This process includes the assessment of the entropy weight...

7 citations

Journal ArticleDOI
21 Mar 2020
TL;DR: In this article, the authors used a baroclinic three-dimensional (3D) hydrodynamic model, employing wind, tides, and density variations, resulting from the differences of temperature and salinity, as the model input.
Abstract: Highlights The results of the model and observation showed the similarity of the amplitude and phase formed At the highest tide was in the position above the Sea Mean level and the current velocity was lower than when heading to the tide There was a difference in the direction of the current when heading towards high tide Stratification of the water column in both seasons tended to be classified in well-mixed waters Abstract Balikpapan Bay is significant as a link between the cities within and outside of East Kalimantan by becoming the primary path used for local transportation and distribution of produced goods. The various anthropogenic activities increased liquid wastes and debris, which flowed through channels and rivers along the bay. This study aimed to determine tidal current patterns in Balikpapan Bay and its influence on salinity and temperature distributions. This study applied a baroclinic three-dimensional (3D) hydrodynamic model, employing wind, tides, and density variations, resulting from the differences of temperature and salinity, as the model input. To simulate the tidal current flow, we applied MOHID Water Modeling System, which the tidal current patterns depicted current directions and speeds at the different tidal conditions. During the displacement toward the high tidal condition, the water mass moves northwestward entering the river body, while at the displacement toward the low tidal condition, the water mass moves southeastward, which flows toward the coast and without the bay. The current speed varies at certain tidal conditions. At the highest tidal condition, the surface elevation ranged 1.3 - 1.5 m above mean sea level; the current rate is lower compared to the displacement toward high tidal condition, which ranged from 0.01 - 0.15 m/s. At the lowest tidal condition, the surface elevation reached 1 - 1.2 m below mean sea level, and the weaker flow velocity took place (less than 0.15 m/s). The results also showed that the water mass temperature tends to be higher in the inner part of Balikpapan Bay, the Balikpapan Bay waters profile that is increasingly shallow towards the bay head also causes this area to tend to have a higher temperature. Also, areas located on the inside of the bay tend to get more freshwater input from rivers, so this area has lower salinity while the area located at the mouth of the bay tends to be of higher salinity because it gets a lot of mass input of seawater from the Makassar Strait.

5 citations