Center for Scientific Publication
Not a member yet
4029 research outputs found
Sort by
Study of Variation of Binder Materials On Permeability Of Foundry Green Sand
Get PDFThe preparation of standards and procedures for the production process in the manufacturing industry plays an important role in achieving acceptable products and in accordance with the desired quality. Based on the data from the quality control report of a foundry company, casting defects slightly exceed the maximum reject rate. It was found that the moisture content in the molding sand produced according to the procedure exceeded the maximum water content in the molding sand. The research was conducted as an effort to improve the quality of the company's production in reducing reject products. Permeability values of molding sand and quantitative area of cast defects will be compared, as a variations of bentonite and molasses binders , in three variations of the percentage addition of binder, respectively: 1, 3, and 5%. The Anova Two Way approach was used to statistically assess the results of the permeability test of the test specimens to ensure the effect of the predictor variables on the response. The results indicated that the more molasses, 5% added to the molding sand, gave the highest permeability of 53.50 ± 0.50 cm3/minute and gave the lowest cast defect area of 11.97%. The addition of bentonite binder produces a phenomenon that is inversely proportional to the addition of molasses binder
Analysis Of Docking Space Availability In One Web-Based Application For Shipyards In The Samarinda Region
Get PDFThe development of the national shipping industry, especially shipyards, can increase the capacity of the national shipping industry in transporting goods and passengers between islands. Digitalization allows for major changes in business models that allow the creation of new companies that grow very quickly. Digitization can make new jobs easier by using technology in such a way to be used as efficiently as possible. Digitalization has created a business model that allows for a more practical concentration of the technology industry than the traditional business model. Based on information obtained in the field, shipyards in Eastern Indonesia, especially in the Samarinda and East Borneo regions, can improve the local economy, so that the schedule for the production of new building ships in the shipyard must be accommodated, upgraded to be more modern, After observations were made at several shipyards in Samarinda there appeared obstacles in the work carried out including: outsourced labor, area and waters depending on weather factors the work device still using standard technology, with these obstacles, the author tried to analyze the process of availability of shipyards in the Samarinda region using the fishbone diagram method of the purpose of the study this and all obstacles or problems faced by the shipyard through fishbone analysis and from the results of this research the result to be achieved is to make an application so that the administrative process is neat, repair and shipbuilding in the program properly and scheduled, also including repairs/maintenance, with an application-based or web-based business can help improve the business, because it will make it easier for shipowners to access adequate shipyards that are scheduled and have a location and place that suits the condition of their ships without making many long voyages to get a docking place with uncertainty of schedules
Flettner Rotor Modification through Adding Ridges and Fins with Results Comparison to Base Model
Get PDFOceans are the most crucial factor in maintaining global environmental equilibrium. Researchers are looking into the possibility of capturing wind power for shipping. Ship builders and owners provide several solutions based on the use of electrical power, low-polluting fuels, solar energy, and wind energy. The goal of this research is to learn more about using Flettner rotors as alternate sources of power and to create a new operational model for the rotor that could generate more power output from the currently available base model. Due to the sluggish market and glut of tonnage, the global shipping industry is now having difficulties. Only a few ships have wind-assisted technologies to help them save money on fuel. For the research, we created a base model in the 3D program from the available data about the commercially used Flettner rotor, then we modified a number of variations for the model and compared the results we reached from the CFD software to find an outcome that is better than the current output of the base model, and the results have shown improvement for the lower wind speeds
Strength Analysis of LCT Lady Primus 39.5 m Ramp Door Structure Due to Changes in Tilt Angle Variations and Load Variations
Get PDFOf the several cases of accidents, the fall of a vehicle from a ship during loading and unloading occurred due to a break in the clevis ramp door. This study focused on the construction of the ramp door of the ship LCT Lady Primus 39.5 m. The purpose of this study is to determine the voltage characteristics that occur in ramp door construction, determine the location of the most critical components in ramp door construction, and determine the safety factor value in ramp door construction under each loading condition. This research uses the finite element method (FEM) and refers to the Indonesian Classification Bureau (BKI) rules. The vehicle loads used in this study were the Uro Vamtac, Panser Anoa, APC Komodo, and BMP 3F Tanks. The variations given are in the form of angular conditions of +108, 08, and -108. Validation was carried out on the model by comparing the results of simulation calculations with analytical calculations, and an error value of 2.8% was obtained. The material used is KI-A36, with a yield voltage of 235 Mpa. The results of the FEM analysis (finite element method) obtained a maximum stress of 82.31 Mpa located on a stiffener length 3 precisely at node 1249. The most considerable strain of 1.929 mm is located on the top plate at node 20495. The research results on cargo variations and tilt angles of the LCT Lady primus 39.5 m ship ramp door have met the criteria of the Indonesian Classification Bureau (BKI) rules.
The Study of Changing Anchor From Launching Model to Hanging Model on Barge Ship Owned by P.T. X
Get PDFAnchor is a device for tethering a ship to the bottom of the water, in the sea, river, or lake, so that it does not move from place to place due to gusts of wind, current, or waves. Anchors are heavy equipment that is dropped to the seabed from a ship or boat to maintain its position so that it does not drift. PT X has several tug boats, small vessels whose function is to pull or push large ships in port. In addition, this ship also functions to pull barges filled with coal from the coal processing plant to be brought to the port, where the coal is unloaded to be carried by transport trucks. On these barges, damage to the anchor machine often occurs, especially the teeth on the gear-box, axle pulleys (pulleys), the main shaft of the main-gear (main gear), the gear-box casing, the teeth on the main-gear and others which have been sufficient so far. Interfere with operations, and the ship becomes idle. For this reason, this research was conducted to study the change in the anchor system from the glide model to a new system in the hanging model, in order to reduce the use of anchor winch power and avoid damage to the gear-box and anchor engine
Model Kredibilitas Bühlmann-Straub untuk Frekuensi Klaim Berdistribusi Binomial Negatif–Lindley
Get PDFThe credibility theory is one of the tools that can be used to determine risk-based premiums. One approach that can be used is the best accuracy approach such as Bühlmann-Straub. We study the parametric Bühlmann-Straub credibility model in which the claim frequency data is assumed to follow the Negative-Lindley (NB-L) Binomial distribution. Determination of the Bühlmann-Straub parameter is determined by using the basic rules in probability theory. From the study that has been carried out, an explicit equation has been obtained to determine the credibility premium of Bühlmann-Straub. A simulation of the application of the model to the data was also provided by assuming the data follows the NB-L distribution. The NB-L distribution parameters were estimated using the momen method and maximum likelihood estimation. From the simulation, it is found that the data used had a high credibility factor value which implies the data can be considered primely for estimating future premiums
Isolasi, Identifikasi Dan Uji Bioaktivitas Metabolit Sekunder Dari Fraksi n-Heksana Kayu Akar Tumbuhan Paliasa (Kleinhovia hospita Linn.) Yang Tidak Aktif Terhadap Udang Artemia salina Leach
Get PDFPenelusuran secara etnobotani dan berdasarkan kajian kemotaksonomi serta filogenetik menunjukkan kayu akar tumbuhan Kleinhovia hospita Linn. (Paliasa) berpotensi menghasilkan metabolit sekunder dengan stuktur beragam dan bersifat bioaktif. Penelitian ini bertujuan untuk mengisolasi, mengidentifikasi dan menentukan bioaktivitas metabolit sekunder pada fraksi n-heksan yang tidak aktif terhadap udang Artemia salina Leach dari kayu akar tumbuhan K. hospita. Metode isolasi yang digunakan terdiri dari ekstraksi, fraksinasi dan pemurnian. Identifikasi metabolit sekunder melalui analisis spektroskopi IR sedang uji bioaktivitas senyawa berdasarkan metode Brine Shrimp Lethality Test (BST) menggunakan A. salina. Hasil penelitian diperoleh dua senyawa yang diduga sebagai steroid alkaloidal dengan nilai toksisitas (LC50) masing-masing senyawa adalah > 1000 µg/mL dan 107,54 µg/mL. Kata kunci: Artemia salina Leach., Kleinhovia hospita Linn., spektrum IR, Sterculiaceae, steroid alkaloidal
Preliminary Study of an Integrated Calculation of Ship Strength on Tankers with Applicable Regulations
Get PDFRecently, the development of the digital era has increased significantly. Industry 4.0 began to be discussed and applied in the early 21st century. Cyber-Physical systems are becoming a trend in current technological developments. Several technologies in Industry 4.0 are being applied, such as the internet of things, cloud computing, automated simulation, intelligent robots, big data analysis, augmented reality, and additive manufacturing. The shipyard industry is one industry that must be able to adapt to keep up with technological developments. In the ship's preliminary design stage, the strength calculation process that refers to certain regulations has an important role in the design process. The integrated calculation system will make working easier for a naval architect. This paper aims to conduct an initial study in calculating ship strength integrated in real-time with the regulations that govern it. This study produces an idea to integrate the calculation of ship strength with regulations from a class society that continues to grow. The research is expected to provide further development to assist in the preliminary design process that provides efficiency and more accurate monitoring of results
Experience in Oceanographic Surveys for Designing 100 kW Tidal Current Energy Conversion Systems
Get PDFNowadays tidal current energy conversion system (TCECS) is being developed with a capacity of 100 kW for Indonesian waters. The design process is based on the results of field measurements, i.e., ocean currents, tides, ocean waves, and bathymetry. This paper aims to explain the experiences when collecting oceanography data in a potential site for TCECS. The survey method is that the equipment placed on the seabed will emit signals that can record flow and wave data according to the desired time and depth. The survey process, especially for the tidal current energy application, requires good preparation so as not to fail. The results of this paper explain the challenges and highlight the steps. These are technical, environmental, and survey permits. The technical aspects are tool stability, buoyancy effects, visualization tools with an underwater camera system, seawater brightness, and sedimentation. Environmental aspects are big waves, strong currents, and weather. The survey permit aspects are destruction and conservation area. Therefore, before the survey, safety procedures or documents must be made in the form of HIRA (Hazard Identification and Risk Analysis). The experiences of this survey are a novelty consideration for other surveyors in the tidal current energy aspect
Gap Analysis of Ship Design Approval Case Study: Key Plan Drawing Assessment for Dual Fuel Harbour Tugboat
Get PDFStarting to build the ship, the ship’s designer or builder must prepare key plan drawings with an approval statement that comes from the Classification Society (CS) based on the conformity of key plan drawings to comply with the rules or sometimes do not comply with those rules in several cases, so this situation could be minimized by using a gap analysis technique prior to the approval of the ship design process. Gap analysis is the tool to evaluate whether the design has been conforming to comply with the rules of the classification society or not. This paper chooses some parts of the ship design of a Dual Fuel Harbour Tugboat (DF Tug) to show the level of conformity to the rules. The assessment process involves Biro Klasifikasi Indonesia (BKI) since the DF Tug will be classified by BKI as a competent national classification society. The findings gap is used to improve the design of DF Tug. Finally, the framework of corrections and improvements to the DF Tug design is proposed as part of the refinement of key plan drawings, and the final ship design complies with rules and gets full approval from the classification societ