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Design and Strength Analysis of an Amphibious Multipurpose Dredger for the Eastern Surabaya Shipping Lane and the Porong River in Sidoarjo
Get PDFThis study investigates the problem of sedimentation in the Porong River and the Eastern Surabaya Shipping Lane by taking a close look at the Amphibious Multipurpose Dredger. The study examines the vessel's parameters (length: 14.30 m, breadth: 4.70 m, height: 1.60 m, draft: 1.10 m) in light of the requirements of coastal reclamation. For stability and pressure studies, manual calculations and Finite Element Method simulations are utilised. The results show that the hollow Spud design is superior to the alternatives in terms of material efficiency (Safety Factor: 12.4032). The research makes a substantial contribution by offering an effective way to address sedimentation issues through improved dredger design. Moreover, it emphasizes the crucial part that an adaptable amphibious multipurpose dredger plays in reducing sedimentation. The study highlights the strategic significance of the recommended spud design, satisfying safety regulations and improving operational efficiency, as coastal ecosystems face rising challenges. For practitioners in environmental and maritime engineering looking for sustainable approaches to the development of coastal infrastructure, this paper is an invaluable resource
Conversion of High Speed Landing Craft Boat for Passenger into High Speed Landing Craft Boat for Ambulance
Get PDFThe Riau Archipelago is one of the provinces that geographically consist of 1700 islands surrounded by sea, both small and large, with a percentage of 98% sea and 2% land. So, to support the minimal health facilities on the Riau Archipelago, an Ambulance Boat is needed to mobilize patients to hospitals with better facilities. In this study, it aims to modify the design of the High Speed Landing Craft Boat Passenger to become an Ambulance Boat with a length of 12 m, a width of 3 m, a height of 1.2 m, and a draft of 0.6 m. Then perform technical calculations including hull shape coefficient analysis, stability, seakeeping, resistance, speed, ship power, and Motion Sickness Incidence (MSI) analysis. From MSI analysis with ISO 2631 parameters, the wave heading is divided into 5 sections: 00 (Following Seas), 450 (Stern Quartering Seas), 900 (Beam Seas), 1350 (Bow Quartering Seas), and 1800 (Head Seas). The value MSI is obtained after carrying out a comprehensive analysis, the results are depicted in the MSI chart for sea state 1 calm (0-0.1 m) and sea state 2 smooth (0.1-0.5 m) conditions with the following wave directions, waves coming from the side (beam seas), and waves coming from the front (head seas)
Analisis Tingkat Keamanan Ruang Terbuka Hijau Berdasarkan Variabel Keruangan Dan Fisik Taman: Studi Kasus Kota Surabaya
Get PDFKeamanan adalah kebutuhan mendasar bagi psikologi manusia. Ancaman tindak kriminalitas cukup tinggi di kota-kota besar, hal ini berdampak terhadap rasa aman masyarakatnya. Rasa aman sendiri mempengaruhi bagaimana kehidupan masyarakat dalam menggunakan ruang perkotaan, semakin aman suatu kawasan semakin nyaman pula masyarakat menggunakannya. Ruang terbuka hijau atau taman merupakan fasilitas publik kota yang memiliki probalitas tejadinya tindak kriminalitas tertinggi di bandingkan fasilitas publik lainnya. Kota Surabaya sejak tahun 2010 hingga 2020 terus menambah luas ruang terbuka hijau dan jumlah tamannya, sehingga antusiasme masyarakat untuk berkunjung ke taman juga semakin meningkat. Namun, antusiasme ini dibayang-bayangi oleh resiko tindak kriminalitas, dikarenakan Surabaya merupakan kota dengan tingkat kriminalitas tertinggi se-Jawa Timur pada tahun 2020. Evaluasi tingkat keamanan di taman Kota Surabaya ini penting dilakukan, guna mengetahui peran atribut fisik lingkungan taman dalam mencegah tindak kriminal dan meningkatkan rasa aman. Mix method dengan strategi multi kasus digunakan dalam penelitian ini, serta visual audit dan persepsi masyarakat sebagai alat analisisnya. Kedua alat analisis digunakan untuk mengetahui respon persepsi rasa aman masyarakat terhadap kondisi ideal atribut lingkungan dalam mencegah tindak kriminalitas. Taman Flora memiliki ketercapaian indikator visual audit sebesar 85,7% dan masuk dalam tingkatan “sangat aman”, sedangkan skor rata-rata rasa amannya adalah 4,25 dan masuk tingkatan “sangat aman”. Taman Harmoni memiliki ketercapaian indikator visual audit sebesar 57% dan masuk dalam tingkatan “cukup aman”, sedangkan skor rata-rata rasa amannya adalah 4,13 dan masuk tingkatan “aman”. Kebun Bibit memiliki ketercapaian indikator visual audit sebesar 64% dan masuk dalam tingkatan “cukup aman”, sedangkan skor rata-rata rasa amannya adalah 4,17 dan masuk tingkatan “aman”
Analysis of the Effect of Sinker on Bearing Capacity of Anchor in Calm Buoy Mooring System: Case Study of SBM Pengapon Semarang
Get PDFThe addition of sinkers on the mooring line is generally used to support the anchor in maintaining its position in extreme environmental conditions. In this study, the author will analyze the effect of sinkers on the mooring line tension and the bearing capacity of the anchor. The sinker variations in this analysis are 10, 15, and 20 tons, which will be added to the asymmetric mooring line of CALM Buoy SPM Pengapon Semarang. The type of anchor SPM is Stevpris MK III on soft clay soil type. The author first analyses the line tension in each environmental loading condition and then analyses the anchor's bearing capacity. The analysis results show that the largest tension occurs in line 3 without a sinker in DEC conditions with an environmental load direction of 314.24 deg, 1301.19 kN (End A) and 1310.43 kN (End B). In the analysis of the holding capacity of the anchor, the author refers to the SOF ABS Class 2019 and the charts of Appendix D2 and D6 API RP 2SK. The results indicate that the gradation of weight and position of the sinker causes the line tension between the sinker and the fairlead to increase linearly, with an average percentage increase of 1.35%. Meanwhile, the bearing capacity of the anchor, which includes required holding capacity, anchor weight, and estimated drag distance/fluke length, decreased with an average percentage of 7.46%, 15.39%, and 4.79%. Based on the consideration of the End A tension analysis results in the DEC condition, it is stated that the 20-ton sinker in position 1 is a suitable variation of the sinker in this SPM Pengapon Semarang case study
Risk Analysis Forecasting Models of Poisson Regression, Negative Binomial Regression, Poisson GSARIMA, and Negative Binomial GSARIMA (Case Study: Number of Bicycle Sales)
Get PDFThe Poisson model is a model that can be applied to count data, where in this research the case study used is the number of bicycle sales. However, there is an equidispersion assumption in the Poisson model, that the response variable has the same mean and variance. A more flexible model is needed if the equidispersion assumption is not met, namely the Negative Binomial model. In this research, two models were applied, namely the regression model and the GSARIMA model, with two different distributions, namely the Poisson distribution and the Negative Binomial distribution. Therefore the models that will be compared are the Poisson Regression, Negative Binomial Regression, Poisson GSARIMA, and Negative Binomial GSARIMA models. The differences in results for each model are due to errors that occur in each model used. Hence, a model with a smaller error can be said to be a model that has a smaller risk than other models. The results of this study show that the error rate in the Negative Binomial GSARIMA ZQ1 model is relatively smaller than other models with a value of AIC = 1058.7. This model is the best model that can be used as a forecasting model in the case of bicycle sales and can minimize the risk of error in a forecasting result
The Effect of Sulfate Exposure on The Mechanical Properties of Conventional Portland Composite Cement Concrete
Get PDFThe durability of concrete is an essential factor in construction as a means to enhance the quality of public facilities planning. The durability of concrete structures can be degraded due to several factors, one of the factors is sulfate attack concrete. Expose to magnesium sulfate (MgSO4) causes more aggressive damage compared to sodium sulfate. The negative effect of sulfate exposure is the accelerated formation of microcracks that lead to concrete deterioration. This study aims to investigate the influence of expose to a 5% magnesium sulfate solution on the mechanical properties of Portland composite cement concrete (PCC). Sulfate exposure was conducted after the PCC concrete was cured in water for 28 days. Observations and testing were carried out in four stages: before exposure, after 28, 56, and 90 days. The compressive strength of the concrete increased by 8.78% after 56 days of exposure but decreased by 7.2% from the 56-day strength during the 90-day exposure. The modulus of elasticity, Poisson's ratio, tensile strength, and fracture energy were directly proportional to the compressive strength values generated during sulfate exposure. Additionally, the mass of the concrete increased by 0.87% after 56 days of exposure and then decreased to 0.56% during the 90-day exposure
Pemanfaatan Selulosa dari Limbah Popok Bayi Termodifikasi Asam Stearat sebagai Absorben Hidrofobik untuk Pemisahan Minyak dan Air
Get PDFPeningkatan penggunaan popok bayi setiap tahun menyebabkan masalah limbah popok bayi yang tidak dapat terdegradasi secara alami. Limbah ini memiliki potensi untuk dimanfaatkan kembali menjadi material bernilai, seperti selulosa dalam Superabsorbent Polymer (SAP) yang dapat diubah menjadi material hidrofobik untuk mengatasi tumpahan minyak di perairan. Penelitian ini bertujuan untuk memodifikasi permukaan selulosa dari limbah popok bayi menggunakan asam stearat sebagai absorben hidrofobik, melalui tiga tahapan: preparasi, pemisahan selulosa, dan modifikasi dengan asam stearat dengan variasi 5, 6, dan 7 gram asam stearat (V1, V2, V3). Pemisahan selulosa dengan asam nitrat dan asam asetat menghasilkan rendemen sebesar 87%. Water Contact Angle (WCA) dari absorben termodifikasi asam stearat menunjukkan nilai 108,552°, 124,327°, dan 127,980° berturut-turut untuk V1, V2, dan V3, yang berarti material ini terkonfirmasi memiliki sifat hidrofobik. Absorben hidrofobik termodifikasi menunjukkan kapasitas penyerapan 3,129 g/g, 0,523 g/g, 0,329 g/g, dan 0,296 g/g untuk selulosa, V1, V2, dan V3, dengan efisiensi pemisahan masing-masing 0,43%, 0,38%, dan 0,37%, lebih rendah dibandingkan selulosa yang mencapai 1,63%. Namun, konsentrasi minyak yang terserap pada parameter uji oli mesin adalah 59,34%, 60,13%, dan 96,84%, jauh lebih tinggi dibandingkan selulosa yang hanya 7,39%. Variasi yang paling unggul berdasarkan nilai WCA dan konsentrasi minyak yang terserap adalah V
An Inventory Model for Deteriorated Item with Time- and Inventory-dependent Demand and Backorder
Get PDFThe paper focuses on developing an inventory model for deteriorated item when demand is time- and inventorydependent. Deteriorated items can usually be found in items such as vegetables, fruit, milk, chemical product, pharmaceutical and it needs special attention in managing this kind of inventory. We model the inventory control for these items by a mathematical model involving time- and inventory-dependent demand and considering the backorder policy in handling shortages. The developed model aims to find the optimal time between replenishment and when inventory drops to zero, which minimizes the total inventory cost. The total inventory cost consists of the purchase cost, the order cost, the holding cost, and the shortage cost. Sensitivity analysis is performed to analyse the effect of changing the parameters’ values to the time between replenishment, when inventory drops to zero, the order quantity, and the total inventory cost. The finding shows that changing the parameters’ values of deterioration rate, demand, unit holding cost, unit holding cost and unit shortage cost will have an impact on the time between replenishment, time when inventory drops to zero, order quantity, and inventory cost
STRATEGIC PLANNING FORMULATION FOR THE DEVELOPMENT OF A GREEN HOUSING ESTATE DESIGN
Get PDFThe rapid development of Balikpapan built environment is influenced by the development of the relocation of Indonesia’s capital city to the East Kalimantan Province. One impact that should be anticipated is the increase in immigrant and land conversion due to infrastructure expansion and the effect on the natural urban ecosystem. The disruption of the natural environment can indirectly affect welfare, such as the lack of accessibility of residents to appropriate resources. The quality of the housing environment has a fundamental significance on the quality of life; however, a measurable design approach is still unseen in the Grand City housing in Balikpapan. This research aims to formulate an improvement design strategy for a green neighborhood following the greenship criteria. Using SWOT analysis, internal and external factors were compiled in the qualitative matrix to generate design strategies. The result shows that internal and external source factors support the improvement by depicting the developed area's strengths and weaknesses. The essential enhancements for the area are the movement and connectivity and the building and energy criteria. At the same time, the other improvements are related to the provision and the development of the existing elements could improve the green innovation of the area to be more environmental-friendly