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Umair Hasan Amin Chegenizadeh Mochamad Arief Budihardjo Hamid Nikraz 《Geotechnical and Geological Engineering》2016,34(6):1707-1722
In this study, the effect of ground granulated blast furnace slag (GGBFS) and recycled construction waste (CW) on bentonite clay stabilisation were investigated. The unconfined compressive strength (UCS) of specimens was evaluated with different combinations of GGBFS and CW over various curing periods. A series of micro analysis tests consisting of scanning electron microscope, energy dispersive spectrometer and X-ray diffraction were also conducted to determine the microstructural arrangement and mineralogical effect of the stabilisation treatment. The UCS results showed an increment in strength after introduction of GGBFS and CW and the longer curing period produced more pronounced results. The optimum additive ratio was calculated as 5 % of slag and 20 % of construction waste under all curing conditions. The micro analytical results also indicated formation of structural bonds between admixtures and bentonite in stabilised specimens, as slag crystals and bentonite particles were observed to occupy the cavities and vesicles on the construction waste grains. However, the experimental data shows that the strength improvement is not significant with the addition of only construction waste. 相似文献
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Vicentius Ochie Arief Kiki Trilestari Jaka Sunarso Nani Indraswati Suryadi Ismadji 《洁净——土壤、空气、水》2008,36(12):937-962
A significant number of biosorption studies on the removal of heavy metal from aqueous solutions have been conducted worldwide. Nearly all of them have been directed towards optimizing biosorption parameters to obtain the highest removal efficiency while the rest of them are concerned with the biosorption mechanism. Combinations of FTIR, SEM‐EDX, TEM as well as classical methods such as titrations are extremely useful in determining the main processes on the surfaces of biosorbents. Diverse functional groups represented by carboxyl, hydroxyl, sulfate and amino groups play significant roles in the biosorption process. Solution pH normally has a large impact on biosorption performance. In brief, ion exchange and complexation can be pointed out as the most prevalent mechanisms for the biosorption of most heavy metals. 相似文献
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徐勇航 王亮 赖志坤 徐晓辉 王凤 刘升发 石学法 TROA Rainer Arief ZURAIDA Rin TRIARSO Eko HENDRIZAN Marfasran 《海洋学报(英文版)》2019,38(1):78-84
通过对东印度洋钻孔CJ01-185的生物硅来探讨东印度洋古生产力的变化和古气候演化的响应。CJ01-185钻孔的生物硅含量在末次冰期最低，为0.86%；而到了全新世晚期生物硅含量达到1.89%。全新世晚期生物硅的堆积速率明显大于末次冰期。随着全新世海平面的快速上升，巽他海峡贯通，来自爪哇海的陆源物质输入到东印度洋，导致全新世的生物硅含量和生物硅的堆积速率增加。研究表明：巽他海峡贯通前，研究区的古生产力主要受东南季风变化和上升流的活动影响；而巽他海峡贯通后，古生产力很明显受到陆源物质输入的控制，东南季风变化和上升流的影响较弱。 相似文献
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2013年4月，2014年5月，2012年6月和2015年10月在印度尼西亚北部苏拉维斯蓝碧海峡（Lembeh Strait）进行了4个航次的海洋生态调查，研究了蓝碧海峡的浮游植物种类组成，以及浮游植物群落结构的季节变化及其驱动因子。四个航次的调查中记录了5类浮游植物和416个种（类）。调查区浮游植物密度平均为2348cells/L，硅藻和甲藻种类最多。蓝藻种类最少，但丰度很高。季风转换期的4月份和10月份浮游植物丰度总量较低，东南季风期间5月份和6月份的浮游植物丰度较高。除了束毛藻（Trichodesmium）之外，常见种是浮游硅藻。浮游植物的丰度和多样性的季节性变化明显。海链藻（Thalassionema）、拟菱形藻（Pseudo-nitzschia）和蓝藻类的束毛藻对群落的不相似性贡献最大。由于蓝碧海峡南部营养盐浓度较高，南部水域的硅藻和甲藻密度稍高于海峡北部。虽然，南北两个水体中蓝藻的分布趋于均匀，但蓝碧海峡南部也有较高密度。与雅加达湾以及中国的一些海湾相比，蓝碧海峡的浮游植物丰度相当低。分析表明，SE季风期间上升流营养盐是左右浮游植物丰度月变化的重要因素。蓝碧海峡浮游生态系原始，且接近天然本底，人类活动背景噪声低，能够清晰地响应大环境的变化，是研究浮游生态系统的理想区域。 相似文献
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Remote gully erosion mapping using aster data and geomorphologic analysis in the Main Ethiopian Rift
The Main Ethiopian Rift (MER) is an area of extreme topography underlain by post-Miocene volcanic rocks, Jurassic limestone and a Precambrian basement. A prime concern is the rapid expansion of wide gullies that are impinging on agricultural land. We investigate the potential contribution of Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) data and geomorphologic parameters to discern patterns and features of gully erosion in the MER. Maximum Likelihood Classification (MLC), Support Vector Machine (SVM), and Minimum Distance (MD) classifiers are used to extract different gully shapes and patterns. Several spatial textures based on Grey Level Co-occurrence Matrices (GLCMs) are then generated. Afterwards, the same classifiers are applied to the ASTER data combined with the spatial texture information. We used geomorphologic parameters extracted from SRTM and ASTER DEMs to describe the geomorphologic setting and the gullies’ shapes. The classifications show accuracies varying between 67% and 89%. Maps derived from this quantitative analysis allow the monitoring and mapping of land degradation as a direct result of gully-widening. This study reveals the utility of combining ASTER data and spatial textural information in discerning areas affected by gully erosion. 相似文献
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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
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Remote gully erosion mapping using aster data and geomorphologic analysis in the Main Ethiopian Rift 总被引：1，自引：0，他引：1
The Main Ethiopian Rift(MER)is an area of extreme topography underlain by post-Miocene volcanic rocks,Jurassic limestone and a Precambrian basement.A prime concern is the rapid expansion of wide gullies that are impinging on agricultural land.We investigate the potential contribution of Advanced Space-borne Thermal Emission and Reflection Radiometer(ASTER)data and geomorphologic parameters to discern patterns and features of gully erosion in the MER.Maximum Likelihood Classifica-tion(MLC),Support Vector Machine(SVM),and Minimum Distance(MD)classifiers are used to extract different gully shapes and patterns.Several spatial textures based on Grey Level Co-occurrence Matrices(GLCMs)are then generated.Afterwards,the same classifiers are applied to the ASTER data combined with the spatial texture information.We used geomorphologic parameters ex-tracted from SRTM and ASTER DEMs to describe the geomorphologic setting and the gullies’ shapes.The classifications show accuracies varying between 67% and 89%.Maps derived from this quantitative analysis allow the monitoring and mapping of land degradation as a direct result of gully-widening.This study reveals the utility of combining ASTER data and spatial textural infor-mation in discerning areas affected by gully erosion. 相似文献
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Syamsidik Rina Suryani Oktari Khairul Munadi Suhada Arief Inayah Zhiaul Fajri 《Natural Hazards》2017,88(3):1503-1521
Ten years after the Indian Ocean tsunami in 2004 and following a long process of rehabilitation and reconstruction, Aceh has finally recovered. After the tsunami, Aceh experienced a dramatic migration of its coastal population away from the city; however, after 10 years, the population has mostly recovered. As new houses have been built and new economic activities commenced in the coastal areas, there is now concern regarding potential future tsunami risks for the city. The initial rehabilitation and reconstruction plan sought to prevent the construction of any new houses 500 m from the coastline; however, this failed to happen. This paper elucidates the reasons why these new coastal communities chose their new housing areas and examines the coastal land use changes around Banda Aceh 10 years after the Indian Ocean tsunami. Questionnaires were distributed to 457 respondents, and multiple logistic regressions were used to examine the reasons for household location selection and whether a possible future tsunami was a deciding factor. To examine the coastal land use changes, a series of aerial images from the Banda Aceh coastal area were digitised. It was found that tsunami history was not a major factor in new household selection; rather, rents and land prices, distance from work, and family connections were the top three reasons motivating households to select new living places. These changes and new settlements have given the city’s disaster management agency the challenge of building more emergency infrastructure in the coastal areas. 相似文献
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Marfai Muh Aris Winastuti Ratih Wicaksono Arief Mutaqin Bachtiar W. 《Natural Hazards》2022,111(1):995-1017
Natural Hazards - Sediment as erosion product can affect shorelines, making sediment transport a key process to consider in coastal and shoreline management. Field surveys and secondary data can... 相似文献
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