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Microplastic Contamination in Urban Groundwater: A Case study From Jakarta Megacity, Indonesia

Scientific World Journal 2024年第1期2024卷

作者： Wilyalodia, Hefty Clarissa Moersidik, Setyo Sarwanto Pratama, Mochamad Adhiraga Program Study of Environmental Engineering Department of Civil Engineering Faculty of Engineering Universitas Indonesia Depok Indonesia

Microplastics, classified as emerging contaminants, are recognized for their pollution of various environments, including groundwater. This study focuses on Jakarta, a major city in Asia where some communities still rely on groundwater as their source of clean water. We analyzed 121 groundwater samples from West Jakarta and South Jakarta to assess microplastic abundance and characteristics including color, shape, size, and material. The study also explored the correlation between microplastic abundance and influencing factors such as distance to septic tanks, distance to temporary waste disposal sites, Escherichia coli concentrations, and total coliform concentrations. The results indicate microplastic concentrations ranging from 28 to 236 particles/L with averages of 104 particles/L in West Jakarta and 78 particles/L in South Jakarta. Fragments were the most common shapes (85.68%), followed by fibers (12.86%), films (0.8%), and microbeads (0.66%). Black (85.93%) was the dominant color of microplastics, followed by red (8.2%), transparent (3.13%), blue (1.76%), yellow (0.75%), and green (0.23%). Microplastic size ranged from 20 μm to 3.76 mm, with the dominant polymer materials being Tencel, cellophane, and polyethylene (PE). Further analysis showed a significant correlation between microplastic abundance and distance to temporary waste disposal sites, with closer proximity resulting in higher concentrations. Trends in correlations between microplastic abundance and distance to septic tanks, E. coli concentration, and total coliform concentration were observable but not significant. Copyright © 2024 Hefty Clarissa Wilyalodia et al.

关键词： groundwater Jakarta microplastic septic tank water well

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Offsets Reconstruction Method for Clock Skew Measurement Over High-Jitter Communication

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SN Computer Science 2025年第5期6卷 1-14页

作者： Sastra, Nyoman Putra Saputra, Komang Oka Teng, Wei-Chung Study Program of Electrical Engineering Faculty of Engineering Udayana University Jalan Raya Kampus Bukit Jimbaran Bali Badung 80361 Indonesia Department of Computer Science and Information Engineering National Taiwan University of Science and Technology No. 43 Section 4 Keelung Rd Taipei 106 China

Measuring clock skew of devices over a network fully relies on the offsets, the differences between sending and receiving times. Offsets that shape a thick line are the most ideal one as their slope is directly the clock skew sought. When some outliers separate from the thick line due to higher delay jitter, current advanced approaches use the lower bound or the majority of offsets to derive accurate clock skew. However, outliers in offsets that shape parallel dotted lines, reduce the availability of offsets in the lower region, and scatter widely the offsets from their majority zone. These conditions drive the current skew estimation approaches to lose their accuracy. This paper then developed a new method, which reconstructs back the outliers into their origin positions, in order to provide ideal offsets for clock skew measurement. The experimental evaluations have demonstrated that the clock skew accuracy of dotted-lines offsets tampered by outliers was improved from 2.1 to 0.9 ppm by the proposed reconstruction method. For a broader purpose, the reconstruction method has been adjusted to be implemented also on non-dotted-lines offsets. The robustness of the proposed method for this case has also been exhibited by the very ideal reconstructed offsets that shape like a thick line. © The Author(s) 2025.

关键词： Clock skew Delay jitter Dotted lines Hough transform

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Development of Rainfall-Runoff Model Using Mock Formula with the Calibration of Stream Discharge in Cisadane Watershed - Indonesia 1st

Development of Rainfall-Runoff Model Using Mock Formula with...

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1st International Conference on Emerging Smart Cities, ICESC 2022

作者： Hidayat, Dina P. A. Legowo, W. D. Sri Farid, Mohammad Doctoral Program of Civil Engineering Institut Teknologi Bandung Bandung Indonesia Water Resources Engineering Research Group Faculty of Civil and Environmental Engineering Institut Teknologi Bandung Bandung Indonesia Civil Engineering Department Universitas Trisakti Jakarta Indonesia

ISBN: (纸本)9789819911103

Rainfall-runoff model is one way to model the amount of rainfall that will become runoff and baseflow. Many models have been developed such as the Mock model which is quite simple but has a fairly good level of accuracy. This study aims to model rainfall runoff with the Mock formula and calibrate the model with measured discharge at one discharge station. This study uses the Cisadane watershed in West Java Indonesia for the location study and Serpong station as the discharge station. The modeling will be carried out with 2 scenarios, a monthly rainfall-runoff model in 1 year and the average monthly rainfall-runoff model for several years. The calibration parameter used is Nash Sutcliffe Efficiency (NSE) and coefficient of determination (R2). From the model results, it is obtained that the model calibration results with a fairly good measured discharge with a satisfactory NSE value and R2 is close to 1. © 2024, Institute of Technology PETRONAS Sdn Bhd.

关键词： Rain

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Polymer-based dampening layer application to improve the operating shock tolerance of hard disk drive

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Journal of engineering and Applied Science 2022年第1期69卷 1-20页

作者： Djamari, Djati Wibowo Yap, Fook Fah Budiman, Bentang Arief Triawan, Farid Mechanical Engineering Study Program Sampoerna University Jakarta Indonesia School of Mechanical and Aerospace Engineering Nanyang Technological University Singapore Singapore Faculty of Mechanical and Aerospace Engineering Institut Teknologi Bandung Bandung Indonesia

This paper discusses a passive vibration control method to improve the shock tolerance of hard disk drives (HDDs) in operating condition (op-shock tolerance). Past works in improving the HDDs’ op-shock tolerance includes (i) parking the head when shock is detected, (ii) installing a lift-off limiter, (iii) structural modification of the suspension, and (iv) installing an external vibration isolation. Methods (i) and (iv) have practical issues, method (ii) works only on single shock direction, and method (iii) requires major engineering design/manufacturing work. Compared to these works, this paper proposes a method which has no practical issues and without requiring major engineering design/manufacturing work. The proposed method is to apply a polymer-based dampening layer on the backside of the baseplate with the purpose of increasing the damping ratio of the 1st bending mode of the baseplate. The location of the dampening layer on the baseplate is first determined by modal analysis and then fine-tuned by non-op-shock tests. The op-shock tolerance improvement is confirmed by op-shock tests where 2.5″ HDD with the dampening layer on the baseplate can withstand a 300G 0.5-ms shock without failure while unmodified HDD can only withstand 250G 0.5-ms shock without failure. © 2022, The Author(s).

关键词： Damping

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Removing or Avoiding the Camera Focus Light Appearing on Glossy or Bouncing Surfaces by Light Guiding and Image Warping 22

Removing or Avoiding the Camera Focus Light Appearing on Glo...

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4th International Conference on Information Technology and Computer Communications, ITCC 2022

作者： Rompis, Lianly Electrical Engineering Study Program Faculty of Engineering Universitas Katolik de la Salle Manado Indonesia

ISBN: (纸本)9781450396820

Digital picture or image becomes more and more important in people's daily life, such as for administration, documentation, active communications, and learning processes. People also demand the exchange of information through digital applications and social media. Taking picture or photo of a document, book, certificate, or thing is usually done by the help of digital scanner, but not all these stuffs can be converted into digital with a scanner. In specific condition people need real image transfer and will take photo of the real view directly using their own digital camera or smartphone camera. From author experience and observations, when taking photos of a document or book or certificate or thing normally with plastic cover or glass surface or bouncing surface, we clearly got an annoying light came from the camera focus light or flash that usually creates noise and messy image. This research was conducted based on the idea to remove or avoid getting the unwanted or disturbing light while taking photos of glossy or bouncing surfaces. A procedure to get a clear and smooth image instead of noise and broken image was derived and implemented by author using light guiding and image warping. These two methods bring accurate images that are necessary for communication needs and facilitate better future works without compromising security policies and people's rights. As the research methodology, author performed literature study, observation, analysis, and implementation. The result of this research offers a good procedure and method that can help people getting clear photos or pictures of a glossy or bouncing surface, advance research to be implemented related to camera technology, and best comprehension to improve photography techniques for future developments. © 2022 ACM.

关键词： Image enhancement

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Assessment of the Impact of COVID-19 Lockdown on the Spatio-Temporal Distribution of PM2.5 in Thailand 1

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8th Asia Conference on Environment and Sustainable Development, ACESD 2023

作者： Simatupang, Cathleen Ariella Piyaviriyakul, Pitchaya Pongkiatkul, Prapat Strezov, Vladimir Boontanon, Narin Jindal, Ranjna Boontanon, Suwanna Kitpati Graduate Program in Environmental and Water Resources Engineering Department of Civil and Environmental Engineering Faculty of Engineering Mahidol University Nakhon Pathom73170 Thailand School of Natural Sciences Faculty of Science and Engineering Macquarie University SydneyNSW2109 Australia Department of Environmental Engineering King Mongkut’s University of Technology Thonburi 10800 Bangkok Thailand Faculty of Environment and Resource Studies Mahidol University Nakhon Pathom73170 Thailand Environmental Engineering and Management Program Department of Energy Environment and Climate Change School of Environment and Resources Development Asian Institute of Technology 12120 Pathumthani Thailand Graduate School of Global Environmental Studies Kyoto University 606-8501 Yoshida Sakyo-Ku Kyoto Japan

ISBN: (数字)9789819733200

ISBN: (纸本)9789819733194

During COVID-19 pandemic several countries have implemented quarantines in response to the virus’ spread, which was considered an emergency. Thailand was under a state of emergency from January to December 2020, which has had an impact on the state of environment. Based on real-time data from the Pollution Control Department, the impact of COVID-19 lockdown on PM2.5 pollution in Thailand was examined. Inverse Distance Weighted interpolation was used to generate a more accurate visual representation of the PM2.5 pollution through a spatial distribution of atmospheric pollutants across the provinces of Thailand. PM2.5 levels in all considered areas reduced considerably between 2017 and 2020, with the most significant decrease occurring during the lockdown period of April-July in 2020. As the pre-COVID-19 period occurred during late winter in Thailand, the monthly average PM2.5 concentrations in all selected provinces were gradually increased from December 2019 to March 2020. During the lockdown period, the concentration of PM2.5 was reduced in Pathum Thani (48.9%), Samut Sakhon (35.6%) Samut Prakarn (33.6%), and Bangkok (31.7%) The spatial–temporal distribution of the PM2.5 levels in Samut Sakhon and Samut Prakarn provinces were analyzed for October 2020, during the new normal period. The results showed a significant decrease in concentration of up to 31% compared to previous years where industrial operations were situated. This study showed that the government enforced lockdown during COVID-19 pandemic was beneficial in understanding the impact of reduced human activities on anthropogenic air pollutants’ concentrations. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.

关键词： COVID-19

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Impact of preparedness on safety behavior in dealing with emergencies on container ships: an analysis of the role of safety knowledge, motivation, and awareness

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Australian Journal of Maritime and Ocean Affairs 2024年第1期16卷 59-73页

作者： Kuncowati Sholihah, Qomariyatus Ciptadi, Gatot Koderi Faculty of Shipping Vocation Hang Tuah University Surabaya Indonesia Business Engineering and Industrial Management Compartment Brawijaya University Malang Indonesia Department of Animal Science Brawijaya University Malang Indonesia Environmental Science Doctoral Study Program Brawijaya University Malang Indonesia

The loading and unloading activities of container ships at the Tanjung Perak Port is imperative, as they can be carried out quickly and efficiently. These ships tend to have a high frequency of visits and possess the largest gross tonnage among ships used for the transportation of goods. The occurrence of an accident involving a container ship can have a detrimental effect on the seamless delivery of goods via sea transportation. Furthermore, the crew be adequately prepared in order to mitigate the risk. As evidenced by research on safety behaviour have not taken preparedness as a factor into consideration when addressing emergencies. Therefore, this study aims to investigate the impact of safety knowledge, motivation, and awareness on safety behaviour in dealing with emergencies on container ships in accordance with relevant regulations. A total of 180 ship crew members served as respondents and it analysed using SEM-PLS. The results showed that preparedness, including safety procedures, emergency training, and crew security culture is an important aspect in dealing with emergencies. Furthermore, this study obtained an R square value of 0.525 in the structural model, indicating that the independent variables have an influence on behaviour, and it was classified in the good category. © 2023 Informa UK Limited, trading as Taylor & Francis Group.

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Comprehensive assessment of water and sediment quality to support sustainable management practices and mitigate potential risks of trace metal pollution in the Johor River Basin, South Peninsular Malaysia

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Ecohydrology and Hydrobiology 2025年第2期25卷 315-329页

作者： Mazilamani, Lelavathy S. Annammala, Kogila V. Martin, Patrick Qi, Liang Y. Sugumaran, Dhinesh Ling, Yong E. Reynard, P.S. Nurhidayat, Agus Syawal, Muhamad S. Sutapa, Ignasius D.A. Department of Water & Environmental Engineering Faculty of Civil Engineering Universiti Teknologi Malaysia Johor Bahru Malaysia Disaster Preparedness and Prevention Centre Universiti Teknologi Malaysia Kuala Lumpur Malaysia Asian School of the Environment Nanyang Technological University Singapore Centre of Environmental Sustainability & Water Security (IPASA) Research Institute for Sustainable Environment (RISE) Universiti Teknologi Malaysia Johor Bahru Malaysia Faculty of Engineering – Industrial Engineering International Study Program University of Indonesia Indonesia Asia Pacific Centre for Ecohydrology (APCE) – UNESCO C2C Indonesia Research Centre for Limnology and Water Resources – NRIA Indonesia Faculty of Environmental Science and Technology – Soegijapranata Catholic University (SCU) Semarang Indonesia

Human activities have caused concerns over the contamination of trace elements in aquatic systems due to their toxicity, long-lasting nature, and ability to accumulate in living organisms. This study evaluated the spatial pattern, environmental hazard, and potential health hazard of 13 trace metals in water and sediment samples collected from the Johor River basin using multivariate statistical techniques in order to identify the impact of both natural and human-related factors on the presence of trace metals in the area. The increased levels of metals in Station S1 indicated a significant impact from municipal, domestic, and industrial waste. The Geo-accumulation Index (I_geo) values for pollution and ecological indices in the sediment of the Johor River Basin ranged from -9.44 to 6.27. The Pollution Load Index (PLI) values ranged from 0.05 to 0.18, and the Potential Ecological Risk Assessment (RI) values ranged from 2.15 to 11.18. These results indicate that the sediments in the Johor River Basin have a low risk of contamination from trace metals. The water's hazard quotient (HQ) had an average value of 0.0001, while the hazard index (HI) had an average value of 0.0003. It is important to increase stakeholders' understanding and concerns regarding the potential long-term human health and ecological implications associated with trace metals in Johor River water. The results of this study offer essential initial information for government entities to implement sustainable management strategies, reducing the likelihood of future trace metal contamination issues in the Johor River basin and similar regions. © 2024 European Regional Centre for Ecohydrology of the Polish Academy of Sciences

关键词： Health assessment Johor river basin Multivariate analysis Sediment quality Trace metals Water quality

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Improvement of PID Based on Fuzzy Logic Controller for Controlling Attitude of a Quadcopter 1

Improvement of PID Based on Fuzzy Logic Controller for Contr...

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1st International Conference of Adisutjipto on Aerospace Electrical engineering and Informatics, ICAAEEI 2024

作者： Rizki Dalimunthe, Ernando Sibuea, Horas Nico L. P. Rama Setiadi, Dirga Jayadi, Akhmad Persada Sembiring, Jaka Pranita, Elka Universitas Teknokrat Indonesia Faculty of Engineering and Computer Science Bandar Lampung Indonesia Politenik Negeri Lampung Informatic Management Study Program Bandar Lampung Indonesia

ISBN: (纸本)9798331507930

The quadcopter has a fairly simple mechanical design because it does not require other drives to perform various movements such as roll, pitch, and yaw. The simplicity of this mechanical design has a considerable impact on the complexity of its control. Therefore, it is necessary to have a good control method to maintain the stability of the quadcopter. The research aims to maintain stability of quadcopter by using a combination of the Fuzzy Logic Controller (FLC) with the Proportional-Integral-Derivative (PID) method, where FLC is used to initialize the input of the PID method to find the quadcopter stability point. The application of fuzzy methods for the initial tuning of PID parameters has proven effective in enhancing the system's fundamental performance, such as overshoot, rise time, and settling time, compared to the conventional PID approach. The proposed method can reduce overshoot by over 20%, with reductions reaching up to 88% in yaw motion. Additionally, the Fuzzy-PID approach significantly improves stability, shortening the time to achieve steady-state by less than 1 seconds for all movements while PID did more than 2s for pitch and roll motions and over 1s for yaw motion. © 2024 IEEE.

关键词： Two term control systems

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Enhancing Search Efficiency: Analyzing Learning Mechanisms in Metaheuristics

Enhancing Search Efficiency: Analyzing Learning Mechanisms i...

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2024 International Conference on Information Technology and Computing, ICITCOM 2024

作者： Nurcahyadi, Teddy Blum, Christian Universitas Muhammadiyah Yogyakarta Mechanical Engineering Study Program Engineering Faculty Yogyakarta Indonesia Institut d'Investigació en Inielligència Artificial Consejo Superior de Investigaciones Científicas Barcelona Spain

ISBN: (纸本)9798350379839

Metaheuristics have evolved significantly in the last few decades. Nowadays, more complex problems and essential applications are emerging, requiring more powerful metaheuristics to handle them. This article analyzes the characteristics and performance of existing metaheuristics, with particular emphasis on their learning mechanisms. Several critical aspects for improvement are identified, and several promising future research areas are recommended. © 2024 IEEE.

关键词： Contrastive Learning

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