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"The findings of numerousstudies on the responses of stream quality indicatorsto different levels of watershed development have been integrated into an impervious cover model. The focus on one development stressor, namely theimpervious cover, allows the decision makers to use the impervious cover model as a watershed planning toolto forecast stream response. In evaluating streamquality, the studies used various indicators such as pollutant loads, habitatquality, aquatic species diversity and abundance, and others. This studyaims to test the applicability of the imperviouscover model as a tool to set the threshold of catchment area developmentbased on the targeted water quality index. Themodel is represented by a linear relationship between the water quality indexas a response variable and catchment area imperviousness as an explanatoryvariable. The study area is an urbanized catchment area of a cascade-pondsystem located at the campus of Universitas Indonesia, Depok, West Java.Estimation of catchment area imperviousness is based on digital globe imageryand digitized based on identified rooftops. The water quality data to computethe water quality indices are collected from previous studies and relatedreports. The targeted water quality index is determinedbased on water use suitability referring to the Indonesian governmentregulation number 82/2001. Basedon the available data, an increasing tendency of temporal variation ofcatchment area imperviousness for each pond can be recognized, while waterquality index of each pond tends to decrease over time. In accordance with landcover distribution, spatial tendency indicates that imperviousness isdecreasing in downstream direction, while water quality index is increasing indownstream direction, in line with the characteristics of cascade ponds. Theresults demonstrate that despite the fact that the available data are verylimited, it is possible to use the linear relationship between catchment areaimperviousness and water quality index as a tool to set the threshold forfuture development on the catchment area of the cascade-pond system at thecampus of Universitas Indonesia with a minimum water quality index suitablejust for recreation activities."

"The findings of numerous studies on the responses of stream quality indicators to different levels of watershed development have been integrated into an impervious cover model. The focus on one development stressor, namely the impervious cover, allows the decision makers to use the impervious cover model as a watershed planning tool to forecast stream response. In evaluating stream quality, the studies used various indicators such as pollutant loads, habitat quality, aquatic species diversity and abundance, and others. This study aims to test the applicability of the impervious cover model as a tool to set the threshold of catchment area development based on the targeted water quality index. The model is represented by a linear relationship between the water quality index as a response variable and catchment area imperviousness as an explanatory variable. The study area is an urbanized catchment area of a cascade-pond system located at the campus of Universitas Indonesia, Depok, West Java. Estimation of catchment area imperviousness is based on digital globe imagery and digitized based on identified rooftops. The water quality data to compute the water quality indices are collected from previous studies and related reports. The targeted water quality index is determined based on water use suitability referring to the Indonesian government regulation number 82/2001. Based on the available data, an increasing tendency of temporal variation of catchment area imperviousness for each pond can be recognized, while water quality index of each pond tends to decrease over time. In accordance with land cover distribution, spatial tendency indicates that imperviousness is decreasing in downstream direction, while water quality index is increasing in downstream direction, in line with the characteristics of cascade ponds. The results demonstrate that despite the fact that the available data are very limited, it is possible to use the linear relationship between catchment area imperviousness and water quality index as a tool to set the threshold for future development on the catchment area of the cascade-pond system at the campus of Universitas Indonesia with a minimum water quality index suitable just for recreation activities."

"The infrastructure of the transportation system plays an important and strategic part in the development of a country and serves to support economic progress by enabling the mobility of citizens and the distribution of goods from one region to another. However, communities have unequal access to the system and there are gaps in the regional infrastructure in Indonesia, leading to the requirement for a mapping of all 33 provincial capitals. In this study, we reviewed provisions for road, sea, air, and rail travel. The mapping result is expected to determine the pattern and the prioritization needed for future infrastructure development. A literature review was performed to establish assessment indicators for the mapping. The weighting of each indicator was based on a survey of stakeholders in transportation sectors, which was then analyzed using the Analytical Hierarchy Process. After weighting was completed, the infrastructure of each provincial capital was assessed to determine ratings from the highest to the lowest rank. Jakarta, Medan, Bandung, Surabaya, and Semarang obtained the highest rankings, while Manokwari, Serang, Mamuju, Ternate, and Palangkaraya were at the bottom. This result shows that provincial capitals in western Indonesia had better assessment results than those in the east. Therefore, improvements to the transportation infrastructure of the latter cities should be prioritized."

"Ballast is one of themain structures for the railway tracks. It can resist the lateral movementunder dynamic loading transferred by the passing trains with repeatedly. Undersome circumstances, ballast can suffer degradation or breakdown due to therepeated loading and maintenance. Ballast is easily exposed to the weatherbecause it is laid on the track. Acid rain affects the performance of therailway track near the industrial and urbanarea. As a result, it starts to foul and the small chips from ballast filledthe void, as well as reduce the shear strength of ballast particles. Thissituation can contribute into the increasing of maintenance frequency andcosting. This paper examines the potential of rubber inclusions in increasingthe shear resistance of rubber-ballast composites in simulated water and acid soakedconditions with several configuration. This lab-based exploratory work is only static load simulation in conventional shear boxsetup measuring 60 mm × 60 mm.The aggregates size is 10 times smaller than actual size of ballast. In orderto identify the shear resistance deterioration of rubber-aggregates mixtureunder poor drainage conditions by soaked a batch of aggregates in water andacid solution for 2 weeks to simulate accelerated weathering effects. The shearresistance did not rise dramatically with the rubber reinforcement. Thissusceptible shear strain plots indicate ductile behaviour on theaggregates-rubber composites. This is evident by the linear rise of shearstress with strain up to approximately 10% for the control samples (CS) untilit reaches a constant value. Note that all the specimens including CS are in aloose state during the testing because there were no tamping been applied onthe samples. Overall the circular patch (CP) specimen was the most favourablethan the other configurations. Both mechanisms contributed to the reducedoverall subsistence, accompanied by an increase in the shear resistance. Theinclusion of rubber elements apparently prevented the dilation of the granularmaterial when approaching the shear failure and the reducing the settlement."

"The main problem with the slurry process is the difficulty in recovering the photocatalyst nanoparticle from water following purification. An alternative solution proposed the photocatalyst be immobilized on magnetic carriers, which would allow them to be recollected from the water suspension following treatment using an external magnetic field. Magnetically photocatalyst composites were prepared using simple heteroagglomeration by applying attractive electrostatic forces between the nanoparticles with an opposite surface charge. The Fe3O4/SiO2/TiO2 photocatalysts were synthesized in an aqueous slurry solution containing Fe3O4/SiO2 and TiO2 nanoparticles under pH 5 conditions. Meanwhile, Fe3O4/SiO2 was prepared by a simple procedure via a coprecipitation of iron(II) and iron(III) ion mixtures in ammonium hydroxide and was leached by sodium silicate. The synthesized samples were investigated to determine the phase structure, the magnetic properties, and the morphology of the composites by X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and transmission electron microscopy (TEM), respectively. The results indicated that the composites contained anatase and rutile phases and exhibited a superparamagnetic behavior. Fe3O4/SiO2 particles, which were of the aggregation spherical form at 20 nm in size, were successfully attached onto the TiO2 surface. The catalytic activity of Fe3O4/SiO2/TiO2 composites was evaluated for the degradation of methylene blue under ultraviolet (UV) irradiation. The presence of SiO2 as a barrier between Fe3O4 and TiO2 is not only improves the photocatalytic properties but also provides the ability to adsorb the properties on the composite. The Fe3O4/SiO2/TiO2 (50% containing TiO2 in composite) were able to eliminate 87.3% of methylene blue in water through the adsorption and photocatalytic processes. This result is slightly below pure TiO2, which is able to degrade 96% of methylene blue. The resulting Fe3O4/SiO2/TiO2 composite exhibited an excellent ability to remove dye from water and it is easily recollected using a magnetic bar from the water. Therefore, they have high potency as an efficient and simple implementation for the dye effluent decolorization of textile waste in slurry reactor processes."

"Thedevelopment of the construction industry in Indonesia has been substantiallycontributing to the enhancement of the social and economic development of thepeople. However, its expansion has also become an issue, as the developmentmight be implicated in the abuse of environmental sustainability when thepractices of conducting the construction project abandon the rules and regulationsof sustainable green construction concepts. Therefore, this study attempted tointroduce a quantitative assessment tool called the Green Construction SiteIndex (GCSI) to evaluate the performance of an ongoing project to meet thesustainable green construction concept. The aim of this study was toinvestigate the effectiveness of GCSI as a quantitative assessment tool tomeasure the implementation of the green construction concept conducted byongoing projects. Data were collected by onsite direct observation, interviewswith key personnel, and project documentation review. Data were organized andanalyzed using descriptive elaboration. The results showed that three aspects,the Efficiency Index (IE), Productivity Index (IP), andAwareness Index (IA), were effective in assessing 10 ongoingconstruction projects, categorized as Non-Commercial Non-Residential Building,Commercial Residential Building, and Commercial Non-Residential Building. Theindex generated using GCSI, upon assessing 10 buildings, was 3.39 and fell intothe Good category with IE = 3.51, IP = of 2.86, and IA= 3.84. Another finding shows that the Project Organizational CommitmentIndex (POCI) to the indicator ofthe GCSI was 3.31 (Good category) with IPOL = 3.36, IPRO =3.49, and IPRAC = 2.75. The capability of the GCSI to identify threeaspects within a construction project simultaneously and comprehensivelysuggests the importance of its function as an effective tool that givesbenefits to not only the contactors, but also to the authorities that controlthe green construction?related performance. Therefore, the GCSI is expected tobe applied as a standardized reference by both the construction industries andregulating authorities. Despite its satisfactory findings, the GCSI needs to befurthered to achieve its reliability and validity to be adopted internationally."

"An efficient Region-Based Image Retrieval (RBIR) system must consider query region determination techniques and target regions in the retrieval process. A query region is a region that must contain a Region of Interest (ROI) or saliency region. A query region determination can be specified manually or automatically. However, manual determination is considered less efficient and tedious for users. The selected query region must determine specific target regions in the image collection to reduce the retrieval time. This study proposes a strategy of query region determination based on the Region Importance Index (RII) value and relative position of the Saliency Region Overlapping Block (SROB) to produce a more efficient RBIR. The entire region is formed by using the mean shift segmentation method. The RII value is calculated based on a percentage of the region area and region distance to the center of the image. Whereas the target regions are determined by considering the relative position of SROB, the performance of the proposed method is tested on a CorelDB dataset. Experimental results show that the proposed method can reduce the Average of Retrieval Time to 0.054 seconds with a 5x5 block size configuration."

"An effective and real-time traffic information network is highly important and could contribute to decreasing traffic volume and costs by reducing fuel consumption and saving time for drivers in reaching their destinations. This study provides an extensive analysis regarding the drivers? acceptance levels of the current implementation of the Intelligent Transport System (ITS) in Kuala Lumpur. A proposed model from the literature review based on the known Technology Acceptance Model (TAM) is introduced. The ITS system characteristics, information quality, system quality, and service quality were investigated as external variables. The resulting analysis showed that information quality is the highest influential factor followed by system quality. The results also revealed that service quality had no effect on acceptance levels."

"Agricultural waste hasincreased colossally with development in agricultural production causing environmentalnuisance and degradation. Utilization of coconut husks, one of such type of waste, as a biosorbent for polluted surface water treatment, wasconsidered in this study. Polluted surface water was gently passed through twosimilar columns loaded with 100 and 200 g of coconut husk char respectively.The treated water samples collected after 30, 60, 90, 120 and 150 mins wereexamined for SO42-, NO3- and PO43-ions concentration. Removal efficiency for SO42-, NO3-and PO43- ions on 100 g coconut husk char after 150mins detention time were 70, 78 and 91% respectively. Freundlich isotherm modelgave a better description of the data (R2 > 0.96). Sorption datawas well described by second order pseudo kinetics (R2 >0.85). An amount of 100 g of the biosorbenthas astrong affinity for these types of ion removal in contaminated water. Coconut huskchar as a biosorbentis a panacea to significant concentrations of polyatomic ions in polluted surface water."