bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical and thermal properties of NR/XSBR composite reinforced with rice husk silica
Authors: Bureewong Namthip , Ruksakulpiwat Yupaporn , Ruksakulpiwat Chaiwat
Published: February 2022

Natural rubber (NR) is a renewable resource that is used in many products. In the production of NR products, other rubbers or fillers may be used to produce a product with required properties. However, most rubbers and fillers are synthetic which are non-environmentally friendly materials. To solve this problem, rice husk ash (RHA) from biomass power plant was used to prepare silica to be used as a filler in rubber by in-situ generation. The purer RHA was prepared by leaching with HCl to remove some metallics and increase silica contents by combustion. The purer RHA was dissolved in NaOH to obtain sodium silicate from RHA (RSS). Carboxylated styrene-butadiene rubber (XSBR) used as synthetic rubber was blended with NR in latex form. NR/XSBR at the ratio of 2:1 was mixed with RSS to obtain NR/XSBR/RSS mixture. Acetic acid was dropped into the mixture until neutral for precipitating silica to obtain NR/XSBR/RSi composite. The mechanical, morphological, and thermal properties of NR/XSBR/RSi composites at different contents of silica (5, 10, and 15 phr) were studied. The NR/XSBR/RSi composite with optimum content was compared with NR/XSBR/CSi composite which prepared silica from commercial sodium silicate (CSS) on mechanical, morphological, and thermal properties.
Polyhydroxybutyrate/polylactic acid blends: An alternative feedstock for 3D printed bone scaffold model
Authors: Surisaeng Jiratchaya , Kanabenja Warrayut , Passornraprasit Nichaphat , Aumnate Chuanchom , Potiyaraj’ Pranut
Published: February 2022

In this research, we developed 3D printing filaments from polyhydroxybutyrate (PHB)/poly(lactic acid) (PLA) blends to further its use in a fused filament fabrication (FFF) 3D printing technique as an alternative feedstock for manufacturing bone scaffold model. The filaments were fabricated with blending ratios of PHB/PLA at 100/0, 90/10, 70/30, 50/50, 30/70, 10/90, and 0/100 %wt. using an extrusion process. Furthermore, 10 phr of polypropylene glycol (PPG) was added as a processing aid to enhance the processability. The results of MFR showed that the suitable temperature for 3D printing of all blended filaments is 190 °C. The changes in thermal properties indicate the partial compatibility between PHB and PLA in the blends. PLA plays a vital role in improving the mechanical properties of PHB. 3D printing filament from PHB/PLA blends has been successfully developed.
Development of Flame Retardant Property on Sodium Silicate Treated Paper Based Materials
Authors: Suttipintu Thitiporn , Lhosupasirirat Siraprapa , Osotchan Tanakorn , Srikhirin Toemsak
Published: February 2022

The preparation of cellulose-based flame retardant paper treated with sodium silicate and silicon dioxide (SiO2) colloidal particle by simple immersion process is reported. Cellulose-based paper was preheated at 90°C for surface preparation. The heat treated paper was immersed in solution of sodium silicate-SiO2 at different immersion time ranging from 15 min to 24 hrs. Treated solution diffused into paper coated on the paper fiber and filled the void in the paper microstructure. Treated paper was heated at 90°C to convert an impregnated sodium silicate-SiO2 precursor into silicate framework. The treated paper showed Vsym Si-O-Si from siloxane bond at 792 cm-1 which confirmed a presence of SiO2 in paper. Treated paper at 1 hr immersion showed the highest weight percent gain (WPG) of 40% and total combustion time was improved to 14 sec.
Spectral fiber dosimetry with beryllium oxide for quality assurance in hadron radiation therapy
Authors: Metzner E. , Bäumer C. , Behrends C. , Dammene Debbih A. , Döhler D.D. , van Goethem M.J. , van der Graaf E.R. , Kahle P. , Lühr A. , Teichmann T. , Timmermann B. , Weinberger D. , Werner T. , Wulff J. , Kormoll T.
Published: February 2022

Using the radioluminescence light of solid state probes
coupled to long and flexible fibers for dosimetry in radiotherapy
offers many advantages in terms of probe size, robustness and cost
efficiency. However, especially in hadron fields, radioluminophores
exhibit quenching effects dependent on the linear energy
transfer. This work describes the discovery of a spectral shift in
the radioluminescence light of beryllium oxide in dependence on the
residual range at therapeutic proton energies. A spectrally
resolving measurement setup has been developed and tested in scanned
proton fields. It is shown that such a system can not only
quantitatively reconstruct the dose, but might also give information
on the residual proton range at the point of measurement.
Development and evaluation of a thallium (I) bromide dosimeter for intracavitary radiotherapy quality assurance
Authors: Han M.-J. , Yang S.-W. , Jung J.-H. , Lee D.-H. , Kim J.-Y. , Cho S.-J. , Kim K.-H. , Mun C.-W. , Cho H.-L. , Park S.-K.
Published: February 2022

In intracavitary radiotherapy, incorrect source locations
can result in excessive doses to normal tissues. Therefore, it is
essential to accurately evaluate the source location. In this study,
we investigated a digital line dosimeter based on thallium (I)
bromide (TlBr) to improve the existing analogue verification
method. Therefore, a polycrystalline TlBr unit cell dosimeter was
manufactured, and the measurement performance of iridium-192
(Ir-192) sources was evaluated. We found that the dosimeter's
reproducibility satisfied the evaluation criteria of 1.5% with a
relative standard deviation of 1.44%. Moreover, the linearity
showed excellent results (linear coefficient, R
2 = 0.9999). The
distance dependence showed a difference of 0.03 cm at 50% intensity
when compared to the inverse square value, whereas the angular
dependence showed a large difference when compared to a diode. As
the angle increased, the intensity gradually decreased, resulting in
a difference of up to 41.9%. These results demonstrate the
excellent performance of the TlBr dosimeter. However, because of the
significant influence of angular dependence, a measurement distance
that minimises this error should be applied when manufacturing line
dosimeters in the future.
Bootstrapping Dirac ensembles
Authors: Hessam Hamed , Khalkhali Masoud , Pagliaroli Nathan
Published: February 2022

We apply the bootstrap technique to find the moments of certain multi-trace and multi-matrix random matrix models suggested by noncommutative geometry. Using bootstrapping we are able to find the relationships between the coupling constant of these models and their second moments. Using the Schwinger–Dyson equations, all other moments can be expressed in terms of the coupling constant and the second moment. Explicit relations for higher mixed moments are also obtained.
Volatile compounds in human breath: critical review and meta-analysis
Authors: Issitt Theo , Wiggins Laura , Veysey Martin , Sweeney Sean T , Brackenbury William J , Redeker Kelly
Published: February 2022

Volatile compounds contained in human breath reflect the inner workings of the body. A large number of studies have been published that link individual components of breath to disease, but diagnostic applications remain limited, in part due to inconsistent and conflicting identification of breath biomarkers. New approaches are therefore required to identify effective biomarker targets. Here, volatile organic compounds have been identified in the literature from four metabolically and physiologically distinct diseases and grouped into chemical functional groups (e.g. methylated hydrocarbons or aldehydes; based on known metabolic and enzymatic pathways) to support biomarker discovery and provide new insight on existing data. Using this functional grouping approach, principal component analysis doubled explanatory capacity from 19.1% to 38% relative to single individual compound approaches. Random forest and linear discriminant analysis reveal 93% classification accuracy for cancer. This review and meta-analysis provides insight for future research design by identifying volatile functional groups associated with disease. By incorporating our understanding of the complexities of the human body, along with accounting for variability in methodological and analytical approaches, this work demonstrates that a suite of targeted, functional volatile biomarkers, rather than individual biomarker compounds, will improve accuracy and success in diagnostic research and application.
Location Analysis Of Patrol Boat Fin Stabilizer Based On Numerical Method
Authors: Kusdiana Wawan , Semin  , Made Ariana I , Kusuma Cahya , Ali Baharudin
Published: February 2022

The fin stabilizer is located on the hull of the ship, one left and one right, which is connected to the fin stabilizer control room as a tool to respond to excessive ship rolling in both directions. In this study, we will analyze the ship resistance due to the addition of a fin stabilizer type Naca 0013 on patrol boats with variations in angles of 0°, 5°, 10°, 15° with speed variations of 25 - 30 knots. Calculation of ship resistance using Maxsurf modeler software and Numeca fine marine. In the early stages of validating the model that has been tested on a towing tank with a patrol boat design made using the Maxsurf modeler and Numeca fine marine. Validation results with a maximum error of 2.38% maxsurf software and 2% Numeca software. There was an increase in resistance due to the fin being installed at an angle of 0° by 0.56% - 1.22%, at an angle of 5° by 2.26% - 3.75%, at an angle of 10° by 6.48% - 9.49%, at an angle of 15° by 13.92% - 18.79 % of the total drag of the ship.
System Dynamics Modelling for a Sustainable Natural Gas Supply and Demand in Indonesia to Meet up the Additional Demand of 52 Converted Power Plants
Authors: Purwosaputra A A , Artana K B , Dinariyana A A B
Published: February 2022

US Trade Representatives at WTO had recently excluded Indonesia in the list of Least Developed countries. One of the reason behind the decision was that considering the potential economic of Indonesia that has consistently shown positive trend of growth. As the economic and population growth, the energy demand in Indonesia is also increasing over the time. Indonesia has an abundant natural gas reserves and in fact is the largest reserves in Southeast Asia. In line with the increasing of global awareness toward the sustainable development and environmental concerns, choices over an affordable source of energy with a less carbon footprint is inevitably. With the latest LNG technology, has made distribution even possible to reach remote areas of Indonesian archipelago. The Indonesian government had set up a strategy to promote the use of natural gas in power generation. The Ministerial Energy and Mining Resources Decree No. 13 K/13/MEM/2020 (Ministerial Energy and Mining Resources, 2020e) issued, January 2020, has mandated the state owned enterprise PERTAMINA to establish LNG supply within 2 years time frame to support the conversion of 52 power plants from diesel fueled to natural gas. This study, is offering stages of research, first is determining supply and demand of natural gas in Indonesia, and then conducting a market analysis. A market review analysis on gas supply and demand is done upon various sectors, ie power plants (in relation to additional demand for the conversion of 52 power plants), industries, transportation and households. From which, it will be analyzed, whether or not the gas supply meet the demand. The result of the simulation is revealing the fact that there will be deficit of supply starting sometime in 2031 (much earlier than Asia Pacific Energy Research Centre’s prediction by 2040), with short gap of about 55 MTPA by end of simulation time, thus if the Government is deciding to maintain the existing export commitment.
Ship production process monitoring application using QR-code technology
Authors: Arif Mohammad Sholikhan , Supomo Heri , Alifia Windha Umi , Wahidi Sufian Imam
Published: February 2022

Process monitoring of ship production in Indonesia is currently still using conventional methods. Ship production has stages, preparation to the erection. Each of these stages has results that need to monitor and their progress recorded. Therefore, it is necessary to have a system that fasts, practical, and responsive monitoring directly in the work area for actual conditions; one solution is a QR-code technology-based system. The design steps are making the basic framework, diagram of the relationship between entities, prototype design, central page division. These systems are formed in a website called Ship Building Monitoring Process based on QR-code SBMQ. Technical analysis is carried out by making applications, managing system security, creating business processes and operational systems, implementing them with simulations and trials. The trial application of the SBMQ website determines the contribution of implementing the website monitoring process of ship production. The trial was accompanied by the distribution of questionnaires from samples of shipbuilding practitioners. The SBMQ ship production monitoring system can accelerate review, tracking, and report verification assessment with practitioners is 3.125 with a good category.
Analysis of Mooring Line Tension in Floating Collar Net Cage
Authors: Adaalah A H , Prastianto R W , Murdjito  , Syalsabila F , Syarifudin M R
Published: February 2022

World fish production is increasing every year. This is mainly because of the trend to use floating net cages in aquaculture. One of the common net cage types is the collar cage. The net cage system must withstand the environmental and accidental loads, particularly on the mooring system as its function to maintain the position. Thus, this study focuses on analysis in mooring tension of the fully scaled net cage using numerical methods. The model scale data obtained from a previous experimental study and then scaled up to obtain the fully scaled net cage. After validation, current and wave data at Pangandaran bay, Indonesia is adapted to the simulation. Morison’s hydrodynamic force formula is used. Configuration of the mooring system is a rectangular array with a variation of spread angles of mooring lines between 90°, 60°, and 30°. The load cases used for simulation considering the operation and extreme conditions also the directions in lines and between lines. The result shows that the smallest mooring tension and offset is the configuration 30° in which the mooring lines spread evenly in each direction.
Numerical investigation on the effect of homogenous roughness due to biofouling on ship friction resistance
Authors: Regitasyali S , Aliffrananda M H N , Hermawan Y A , Hakim M L , Utama I K A P
Published: February 2022

Ships are subject to increased surface roughness due to the attachment of biofoulings on their hull. When the surface of a ship’s hull is rough, increased frictional resistance can be expected. A ship’s frictional resistance make up almost 80 – 85% of its total resistance. Therefore, it is crucial to maintain the ship’s frictional resistance value to a minimum. In this study, the effects of roughness length scale due to biofouling on friction resistance are investigated. To achieve reliable results, this study used the 3D DTMB 5415 model that was established as a benchmark study by ITTC. Roughness length scales representing biofoulings are applied to the model and analyzed by using the CFD software at a service speed, reaching a Froude Number of 0.28. Results of the simulation are compared and analysed to gain an understanding of the increased friction resistance value due to biofouling. For the smooth case, the results are in agreement with the towing test conducted by ITTC. In addition, friction resistance is found to be increasing along with the rise of the roughness length scale.
The Influence of NaCl dissolved on biodiesel of used cooking oil on performance and its degradation of main components of diesel engine
Authors: Fathallah Aguk Zuhdi Muhammad , Pinto Fransico
Published: February 2022

Biodiesel has been developed both domestically and abroad. Various studies have been conducted to determine the feasibility and capability of raw materials used cooking oil is replacing diesel oil in the future. The salt content in the raw material for biodiesel (new cooking oil and used cooking oil) could have a negative impact or even do not have a significant effect on the rate of wear of metal on the main components of the diesel engine. Through durability tests, the effect of salt (NaCl) on the main components of diesel engines has been tested. The new cooking oil biodiesel is used as a reference in examining the damage level of the main components of diesel engines. Results of the experiments showed that there is a difference between the use of biodiesel fuel from used cooking oil with new cooking oil such as lower diesel engine performance, carbon deposits generated higher, and degradation of metal elements on the main component in the diesel engine lubricating oil is higher
The Maintenance Task Allocation Analysis in Steam Power Plant: Case Study on Closed Cooling Water System
Authors: Siswantoro Nurhadi , Priyanta Dwi , Suminta Enggar Dywari , Zaman Muhammad Badrus , Pitana Trika , Prastowo Hari , Busse Wolfgang , Nurdiansyah Taufik Reza
Published: February 2022

The closed cooling system is one of the systems that functioned to ensure the cooling water supply can be continuously distributed and ensure that the production process does not cause the equipment or products to overheat, which can result in failure to the equipment and affect the production process due to downtime repair. Reliability Centered Maintenance (RCM) is one of the methods that can be used to analyze the cause of failure, impact, and determination of appropriate and effective maintenance tasks. The purpose of this research is to identify potential failures, determine the maintenance task and determine the optimal maintenance schedule in the closed cooling system of a steam power plant by using the Reliability Centered Maintenance method. The results of analysis on the closed cooling pump, heat exchanger, expansion tank, minimum flow valve, and level control valve obtained a total of 155 failure modes, of which 73% of total failure modes were identified as an evident failure and 27% identified as a hidden failure. While the results of the maintenance task recommendation obtained a total of 155 maintenance tasks which consists of 5 maintenance task categories. They are 88 (57%) of total failure modes recommended to scheduled on condition task, 38 (24%) scheduled restoration task, 20 (13%) scheduled discard task, 3 (2%) schedule finding failure, and 6 (4%) of total failure modes recommended to no scheduled maintenance.
A Case Study Maintenance Task Allocation Analysis on Marine Loading Arm Using Reliability Centered Maintenance
Authors: Siswantoro Nurhadi , Zaman Muhammad Badrus , Fahreza Feizar , Priyanta Dwi , Pitana Trika , Prastowo Hari , Wicaksana Adhitya , Fauzi Haris Nur
Published: February 2022

Marine Loading Arm (MLA) supports all liquid bulk loading and unloading activities, especially imports of chemical raw materials such as NH3, H2SO4, and H3PO4. Therefore, to minimize the occurrence of failure it is necessary to have a treatment method. Reliability Centered Maintenance (RCM) is a maintenance method that focuses on increasing the reliability of components in the system. The RCM uses the principle of risk management to determine tasks and maintenance schedules appropriately. The RCM process is implemented using American Bureau Shipping (ABS) Guidelines. According to the results of this research, there are three types of maintenance tasks for MLA, in which category A has 14 maintenance tasks, category B has 21 maintenance tasks, and there are no maintenance tasks in category C. In all maintenance categories for Preventive Maintenance by 54% with 19 tasks, for Condition Monitoring of 37% with 13 tasks, while for Run-To-Failure of 9% with 3 tasks.
Analysis of Bamboo Species Variation Effect Against Physical and Mechanical Properties of Laminate Bamboo Slat for Fishing Boat Construction Materials
Authors: Supomo H , Supomo W S , Setyanto T D , Solikhan Ariel M , Wachidi S I
Published: February 2022

Several studies on the mechanical properties of bamboo slats have been carried out using various types of bamboo species, including Dendro Calamus Asper sp, Gigantochloa Apus sp, Bambusa Arundinacea sp. Until now, variations and combinations of bamboo species have not been carried out, especially about physical and mechanical properties. This paper investigates the effect of variations in bamboo species on the physical and mechanical properties of laminated bamboo slats for ship construction. Each species of bamboo has advantages and disadvantages, which are expected with this combination will produce better physical and mechanical properties. The best value of shrinkage properties occurred in the variation of Bambusa Arundinacea sp with Gigantochloa Apus, namely 3.86 %. This variation also extends the highest mechanical properties: Tensile Strength: 151.9 Mpa; Flexure Strength MOR: 118.6 Mpa; MOE: 5.54 GPa. The Bambusa Arundinacea sp and Gigantochloa Apus hybrid perfectly meet the limit requirements according to the rules of BKI: 2013, Vol vii.
Analysis of Eddy Current Testing Detection Ability to the Varied Longitudinal Cracks on Coated Weld Metal Tee Joint of 5083 Aluminum Ship Structure
Authors: Hendroprasetyo Wing , Jati Andrian Henry Haidar
Published: February 2022

Due to its service, crack sometimes occur on the coated 5083 aluminum weld metal. One method for finding crack under protective coating is by using eddy current testing (ECT). This method of nondestructive testing relies on a circular electrical path generated by the coils positioned just above the surface being examined. The purpose of this research is to analyze the sensitivity of ECT by using variety of crack dimensions on 5083 aluminum welded plate tee joint. Five test pieces, each 200 mm × 50 mm × 10 mm were used and each sample contain four cracks. Artificial cracks are fabricated using electrical discharge machining (EDM) with length and depth variations. Variations in crack length are 5.0 mm, 7.0 mm, 9.0 mm, and 15.0 mm, and variation in depth are 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm and 2.5 mm. Results obtained by the analysing height and average length of the crack signal indication are as follows: for 0.5 mm crack depth, the height of the crack signal is 5 mm; 1.0 mm depth is 11.75 mm; 1.5 mm depth is 19.75 mm; 2.0 mm depth is 26.5 mm and 2.5 mm depth is 31.25 mm. The degree of accuracy obtained for the detection of crack depth is 93.57%. For the detection of crack length, it is found that the measured average length of artificial cracks is 5 mm actual crack length has measured crack length of 6.32 mm; 7 mm actual crack length has measured crack length value of 7.18 mm; 9 mm actual crack length has a measured crack length value of 8.8 mm and 15 mm actual crack length has measured crack length of 14.48 mm. The degree of accuracy obtained for crack length detection is 91.31%.
Study on Probabilistic Risk Assessment Model for Crossing Situation in Sunda Strait
Authors: Prastyasari Fadilla I. , Shinoda Takeshi
Published: February 2022

Sunda Strait is a busy channel where cargo vessels could probably have a crossing situation with roro ferries. Due to a very limited record of the actual crossing collisions in Sunda Strait, this study performs a Probabilistic Risk Assessment (PRA) of near miss crossing situations in Sunda Strait due to the Traffic Separation Scheme (TSS) that has been set since July 1st, 2020. The analysis is based on the Automatic Identification System (AIS) data during three time-intervals (TI), the first two TIs represented the condition before the TSS came into force, while the last TI was taken after the TSS has been set. The traffic in Sunda Strait was categorized to eight vessel courses, two conditions and seven crossing zones. We proposed a new perspective for the evaluating the TSS by looking at the crossing situation with three different bases, namely crossing zone basis, course basis, and vessel type basis. The probability of a crossing situation was calculated based on the hour basis for each time interval. The UK HSE standard for individual risk is utilized and it is found that the TSS effectively reduced the frequency level of crossing situation from unacceptable to ALARP in CZ 1, 2, and 4. While in CZ 3, the frequency is decreased dramatically from unacceptable to acceptable level.
The effect of propeller cap angle and fin size of PBCF on propeller performance
Authors: Trimulyono A , Jatmiko A B , Mulyatno I P , Yudo H
Published: February 2022

The propeller was one of the main propulsors in ships that consumed a lot of fuel due to the viscous force acting in the ship. Therefore many studies have been carried out to increase the performance of ship propellers. One of the ways is using Energy Saving Device (ESD) to improve propeller performance. One of the ESD is Propeller Boss Cap Fins (PBCF). PBCF was used to improve the propeller performance by reducing the hub vortex during propeller rotation. In this study, we compare the propeller performance before and after PBCF installation without changing propeller dimensions. The variations of PBCF fins were made in 0,1D, 0,2D, and 0,3D with a combination of the angle of the propeller cap were 15° and 20°. The propeller performance is carried out with the computational fluid dynamics (CFD) method. It was made in the open water assumption to reduce of wall effect. B-series propeller is used in the present study. The validation of propeller performance is made using empirical results. This study aimed to determine the effect of the installation of PBCF on the performance of B-Series propellers on the Ro-Ro 1000 GT ship. The results show that variation with a fin diameter of 0,2D and a propeller cap of 20° can increase propeller efficiency by 0.03%. It can be concluded the addition of PBCF can improve propeller performance.
Comparison of shallow water effect on a monohull and chine catamaran
Authors: Sulistyawati W , Sudjasta B , Waskito D Y
Published: February 2022

Many modifications to the hull shape have been made to obtain the optimum hull to reduce resistance. Various modifications of hull shape, as well as with the addition of the number of hulls, become multihulls. This study conducted a comparative study of monohull rounded and chine catamarans on the squat factor by varying the water depth ratio h/T 1.2, 1.3, and 1.5. The analysis is also carried out on the sinkage and trim factors by varying the ship’s trim with changes in LCG points and variations in speed. The simulation results on the effect of depth ratio show that chine catamaran has a squat effect lower than monohull at Fr 0.5. The depth ratio h/T 1.2 of 9.83%, h/T 1.3 of 18.3%, and the h/T 1.5 of 20.69%. At a lower speed Fr<0.3, the monohull has a lower squat effect than chine catamaran. For the effect of 10% LCG trim by stern on the sinkage factor, chine catamaran has a lower value than monohull at Fr 0.5. The analysis results show that chine catamaran has a sinkage effect of up to 40.4% lower than monohull at a ratio of h/T 1.3. In trim by bow conditions, chine catamaran had a lower sinkage effect than monohull at Fr 0.5 with the most significant deviation of 34.21% at a ratio of h/T 1.5. The overall analysis shows that monohull has a remarkable effect on shallow water at Fr<0.3. While at higher speeds, catamarans have a lower influence on the squat, sinkage and trim factors in shallow water conditions.
Intact Stability Analysis of a Container Ship Due to Containers Stowage on Deck
Authors: Anggriani A D E , Baso S , Bochary L , Rosmani  , Hasbullah M
Published: February 2022

Nowadays, the container transportation service increases rapidly and then this condition emphasizes the container ship growth. The containers stowage only on deck can cause a serious problem subjected to ship stability. The objective of present study is to analyze the stability of a container ship due to containers stowage on deck. Also, twelve cases based on weight conditions C1 to C2 were simulated in order to distinguish the impact of the weight on stability parameters KG, GZ, vanishing stability angle, and stability range. The results show the weight condition affects on the magnitude of KG and LCG wherein the position of centre of gravity point is behind amidship and the decrease of LCG due to the decrease of consumable weight ≥ 50% is average 2.06%. The effect of the decrease of consumable weight ≥ 50% can make stern trim condition (C3, C5, C6, C8, C9, C11, and C12). The containers stowage on deck impacts on reducing the KG as well the magnitude GZ becomes small. In addition, the vanishing stability and stability range become small. Nevertheless, the stability parameters due to the containers stowage on deck fulfil the requirement of Intact Stability Code. Overall KG values due to the weight condition (C1 to C12) are significantly lower than the limiting KG. This means that overall KG due to weight conditions fulfill the stability criterion.
Two-phase Flow Analysis for Small-scale Ballast Water Tank Model by Hydraulics Experiment and Simulations
Authors: Liu Guangshuai , Watanabe Toraharu , Shinoda Takeshi
Published: February 2022

This study is utilizing hydraulics experimental and computational fluid dynamics (CFD) methods to verify the flow phenomenon in the ballast water drainage process and discuss the drainage efficiency. In order to facilitate the analysis of the flow characteristics of ballast water in the ballast tank of a typical bulk carrier, the complex structure is simplified into two simple small-scale models, a single-longitudinal model and a single-transversal model. Both are designed with the scale of 1:10 for the data collection. The experimental results are then validated and verified by conducting a two-phase flow model applied volume of fluid (VOF) method. Based on that result, the use of the VOF method is suitable for the ballast water drainage simulation, so it can be used in large-scale model calculations to predict the drainage efficiency of ballast tanks. In addition, this study also conducts a comparative analysis of two configuration modes of the single-longitudinal model and the single-transversal model, which provides a reference for the design and improvement of complex structures.
Open Water and Performance Analysis of Marine Propeller with PBCF Based CFD Method
Authors: Oloan Achdri Fauzi Nugraha , Made Ariana I , Baidowi Achmad
Published: February 2022

Improving marine propeller performance can use ESD ( Energy Saving Devices ), especially located at zone 2 area installation ESD. Focus of this research using PBCF ( Propeller Boss Cap Fins ) as ESD and marine propeller from Japanese Bulk Carrier as object. This research studies marine propeller MP687 with and without PBCF. To obtain data solver, using single domain method and multi domain method. Simulation based on Advanced Ratio ( J ) = 0.30, 0.40 and 0.50. PBCF at multi domain can improve up to ± 4.174 % for thrust, -0.769 % reduce torque value and 1.114% for efficiency increase. Using DES-SST model turbulence, PBCF can imfluence propeller MP687 flow to prevent making hub vortex from trailing edge from each propeller blade.
Review of the Risk Assessment Methods for Shipbuilding in Indonesia
Authors: Ariany Zulfaidah , Pitana Trika , Vanany Iwan
Published: February 2022

In the shipbuilding industry, there is still little discussion and analysis of risk management in the shipbuilding process. From previous studies, it is probable that the material/component group has a high percentage of shipbuilding delays, but there are no publications that discuss ship components specifically. Various models have been developed related to risk assessment in shipbuilding, but mostly discussed on shipbuilding construction, company management and work safety in shipyards. This paper discusses the need for planning and risk assessment models for component availability in the construction of new ships in Indonesia. The aim is to review the methods that will be used in risk assessment, combined with quantitative evaluation methods in the procurement of component materials and ship building installations. The development of methods for risk analysis, with a combination of Failure Mode and Effect Analysis (FMEA) and Bayesian Network (BN) approaches, it is hoped that the most critical risks can be identified so that risk evaluation actions can be carried out.
PT PAL Empowerment Strategy as a Lead Integrator at ALPALHANKAM KCR 60 to Support State Defense at Sea
Authors: Sulistiyanto  , Pujiatmoko Siswo , Mualim Much , Sasongko Nugroho Adi
Published: February 2022

Research on the empowerment of PT PAL as a Lead Integrator on the KCR 60 Defense Security Equipment Tool (ALPALHANKAM) to support national defense at sea as part of the Alutsista readiness within the scope of Defense Management. This study is important because according to the Law Decree No: 16 of 2012 on Defense Industry which states that one of the government-owned defense industries designed as Lead Integrator (main guide) is PT. PAL Indonesia Persero. The tasks and functions of the 60 m Fast Missile Ship (KCR 60) are very significant with a relatively small size but because it is equipped with Anti-Surface Missiles, the “deterrence effect ” becomes very large both regionally and globally. This study has the objective to analyze the condition of the involvement of PT PAL as Lead Integrator in the development and maintenance of KCR 60 and empowerment strategies that must be implemented in order to promote the progress of shipbuilding companies nationwide ground water either owned by the government (SOEs) and private (BUMS) to support national defense at sea. In addition to PT PAL, the role of the TNI-AL as the user of the KCR 60 is very important and dominant so that research is carried out starting from the TNI-AL Headquarters, Koarmada, the Fast Boat Unit in the Koarmada and KRI as a tactical unit carrying out field operations. The research method used is qualitative where primary data collection is done by interview, observation and secondary data derived from literature review and researching facts and data in the field up to the smallest unit, namely KRI and from various publications in the form of books, journals and mass media and social media related to the object of research. The data analysis technique used is the interactive model of Miles & Huberman.
Analysis of fuzzy logic systems types 1 and 2 in identifying of IUU fishing and transshipment: a case study in Indonesia’s vulnerable waters
Authors: Masroeri A A , Aisjah Aulia Siti , Agam Vedanta , Pradenta May , Samudya Muh Arif
Published: February 2022

The identification system for illegal, unreported, and unregulated (IUU) fishing and transshipment of incidents is one effort as early warning and it can be adopted by the Indonesian ministry of fisheries and marine affairs. The system has been developed using several methods. One of them is the artificial neural networks (ANN) have been used, but it is several weaknesses when AIS data is lost. The system able to identify in missing data in a short duration of time only. The development of a system for IUU identification proposed using a fuzzy logic system (FLS). The IUU identification system consists of subsystems: (i) missing data prediction, (ii) anomaly trajectory decision, (iii) IUU selection, and (iv) IUU decision. The performance of FLS is compared between fuzzy type 1 and type 2. The system tested using data of IUU occurrences waters in high frequency. Both SLF type 1 and type 2 are able to give result in very good accuracy for IUU fishing and transshipment identification.
Preliminary design of small semi-displacement passenger ships for the archipelago regions
Authors: Hetharia W R , de Fretes E R , Legwurnitua E J , Uruilal M
Published: February 2022

The development of rapid passenger transport in Indonesian archipelago regions is so fast in recent years. The previous survey conducted by the authors found the typical passenger boats with the capacity of 12 or 20 persons. Those small boats have the difficulties in operating at worse sea conditions. In addition, there are semi-displacement vessels with the capacity of 150 to 350 persons operated from certain seaports. In fact, there is a gap for the vessels with the capacity of 40 to 100 passengers. The purpose of the research is to provide small semi-displacement passenger vessels which may be operated from local small ports provided by the local government. The vessels were designed to follow standard procedure in ship design. The designed ship are small semi-displacement passenger vessels with the capacity of 40, 69 and 103 passengers. The design process was started by input design parameters due to ship missions and continued by design process up to determination of specification at preliminary design stage. The results of research are design specification of three vessels according to their dimensions and configuration. The results of this research should be followed by future detail design in order to provide the documents for the stakeholders.
Review Of Alternative Energy Resource For The Future Ship Power
Authors: Arief I.S. , Fathalah AZM
Published: February 2022

In the near future, reduce emissions from the combustion of the ship’s main engine by increasing the propulsion efficiency of ships that are already operating and/or optimizing ship designs during the design process. The International Maritime Organization (IMO) has introduced stringent regulations to reduce GHG emissions for the global shipping industry. Another solution to reduce emissions is to use alternative renewable energy and clean. This paper will describe what energy is used for ship propulsion nowadays and other alternative energy sources that can be used for main engines, additional or hybrid power. Wind energy, solar PV, and fuel cells are renewable energy options for small ships’ main propulsion, navigation, lighting, and electronic devices. Furthermore, the method used for writing this paper is collecting the best paper and selecting technology alternatives energy that is possible to install on the ship.
Developing 11 x 20 Meter Hovercraft for Military Use
Authors: Santoso Agoes , Zaman Muhammad Badrus , Herjanto Andryan
Published: February 2022

Hovercraft is an advanced marine vehicle that always attractive military gear for supporting all terrain warfare such as fast landing vehicle, beach raid operation, territorial control, etc. Hovercraft capable of amphibious operation to bring troopers and logistics from landing ship to the certain mainland and even reach the city centre. By hovering in the above grounds with low pressure then the hovercraft operation may not activate minefield. Hovercraft also taken into considerations for Indonesian military. A long planning model of 11 x 20 meters class has been developed by applying gas turbine as an alternative main propulsion power for both lifting and thrusting fans. The low of weight/power ratio that offered by gas turbine can improve payload of the hovercraft by 45.85%. This paper also resumes several technical aspects when the hovercraft upgraded to be a fully military use. The results conclude that the additional payload is a significant feature to improve protective hull material, cargo capacity for military gears, weapons system, and logistics. Increasing speed is also possible because of the use of an adjustable blades design in the thruster fans.
The Study of Adaptive Planning Application for LNG Regasification Terminal Infrastructure in Indonesia
Authors: Turbaningsih Oktaviani , Nisa Wahyu Nur Hidayatun , Mustakim Achmad , Nur Iqbal Hasan , Wuryaningrum Pratiwi
Published: February 2022

Global trade for regasification LNG has reached 850.1 MTPA by February 2021 because of the enforcement of clean energy applications. The alternative of renewable energy such as hydropower, solar, and wind has developed globally, but they have not been implemented effectively in Indonesia. LNG became an alternative to clean energy because of its low carbon emissions. An estimated 26% of the 35,000 MW of Indonesia’s electricity supply project comes from natural gas-powered power plants. The scope of this study is to investigate the implementation of adaptive planning for LNG regasification facilities. The authors interview the LNG experts in Indonesia to assess uncertainties, vulnerabilities, and opportunities in its business process to identify the enabling factors for implementing the adaptive method in LNG terminal master planning. This research aims to provide an adaptive strategy for LNG Regasification Terminal to satisfy resilient and sustainable infrastructure concepts. The authors propose the Real Options Analysis using a binomial decision tree to evaluate the decision-making under uncertainty for the infrastructure LNG regasification terminal facilities. The study case for category medium to large scale with 4 MTPA, FSRU concept selected as the suitable configuration, while for the smaller scale facilities with 0.5 MTPA, the FSU with regasification barge selected as the most suitable configuration.
A Systematic Review of the Benefits of Automation Inspection Tools for Quality Housing Delivery
Authors: Nena T D , Musonda I , Okoro C S
Published: February 2022

Efficient and effective inspection is vital for the quality delivery of housing construction. Houses are being inspected less frequently due to incapacitated inspectorates, high cost, and the long duration of the current inspection process. Furthermore, traditional inspection processes often contribute to poor quality housing delivery are inspector dependent and complex and unsafe working environment is exposed to inspectors. Automated inspection technologies play a vital role in the inspection of housing construction. Automation-assisted technologies such as laser scanners, drones and Augmented Reality (AR)-based inspection equipped with multiple imaging and sensing systems have been developed to mitigate some of these issues with the traditional method of inspection processes. This paper reviews relevant peer-reviewed articles to explore automation inspection process tools and technologies and highlight their benefits in the housing construction process. Following the systematic literature assessment methodology, five (5) databases were queried, based on the specific search string. Specifically, 26 journal articles satisfying a set of inclusion criteria were reviewed, its results highlighting the benefits of adopting an automated inspection process for quality housing delivery. The review of the journal articles revealed that the automation inspection process is available with several benefits demonstrating the potential to improve the quality housing delivery with the aid of tools and technologies like Augmented Reality (AR)-based inspection, 3D laser scanning, Drones, and BIM-based inspection. Benefits such as time-saving, limited human intervention during the construction process, inspection accuracy, reduced resource requirements, and improved collaboration between stakeholders. This study also revealed that while new technologies are evolving with benefits to improve the inspection process, there is still a gap in the practical application of these automated inspection process technologies during housing construction. The outcome of this study would benefit both the housing owners (clients), building inspection entities, building construction researchers, and the industry professionals to realise the potential of the automation inspection process and understand the requirements and benefits for their successful implementation.
A Theoretical Assessment on the Implementation of Artificial Intelligence (AI) for an Improved Learning Curve on Construction in South Africa
Authors: Phaladi M G , Mashwama X N , Thwala W D , Aigbavboa C O
Published: February 2022

Generally, the construction sector is lacking behind with the usage of technological software. Artificial Intelligence(AI) technology is viewed as a technological tool that can improve the timeous delivery of construction project(s). Therefore, the study is a literature review on the assessment of the implementation of AI technology on South African construction projects. The qualitative approach and purposive sampling technique were adopted in this study. The primary findings emanating from this study reveals that the past other underground empirical studies have identified several important impacts of AI technology and how it can transform the construction industry. Furthermore, the study findings revealed that if AI technology is fully exposed and exploited on construction projects especially to both developed and developing countries it would certainly improve productivity, enhance efficiency, and performance issues. On the other hand, the level of implementation of AI technology in South Africa is still very low. Therefore, the study would contribute to the body of existing knowledge of AI technology on construction projects, especially in South Africa.
Exploratory Research towards Automated Masonry Construction using UAVs
Authors: Elkhapery B , Small E P
Published: February 2022

Unmanned autonomous vehicles (UAVs), also known as drones, are pervasive in modern society for both recreational and business purposes. Construction sites routinely employ UAVs to capture imagery used for photo documentation, progress reporting, surveying, and inspection. Drones can also carry infrared cameras and LIDAR, increasing opportunities for their use on construction sites. They are not limited, however, to remote sensing and photogrammetric applications. Research is pushing the boundaries to explore other UAV opportunities, such as material deliveries and physical construction. This paper reports on exploratory research to investigate current efforts in automated construction of masonry walls using drones and drone swarms. Masonry was chosen due to the repetitive nature of the processes, which increases the probability of successful implementation. The results of a literature review are first presented to establish the state of the art in this area. The proposed approach will be evaluated based on the construction quality in accordance with standards, entailing both accuracy and precision requirements in the laying process. Approaches for continuing research in drone-based masonry construction automation will be outlined and discussed in the conclusion.
Tightly-Packed Repetitive Schedules: A Tetris Challenge
Authors: Hegazy T , Mostafa K
Published: February 2022

A large portion of new and rehabilitation projects for the civil infrastructure involves repetitive tasks that mandate high degree of synchronization among the resources to meet project constraints. Despite their large need for support, few tools exist commercially. This is due, in part, to the computational and visualization challenges of existing repetitive scheduling techniques, which complicate the process and make it less understood, particularly when the repetitive units are not identical and when resources are limited. This presentation introduces enhancements by dealing with repetitive scheduling as a game of Tetris, where tasks can change geometry to fit tightly together to save project duration. This is demonstrated through novel mathematical formulations, as well as a new heuristic scheduling algorithm (First-Come-First-Serve). It will be shown that the proposed geometrical adjustments are more advantageous in improving repetitive schedules than using expensive accelerations, and the new visuals make the schedule more legible. This research is a step towards making repetitive scheduling a mainstream tool, to benefit the construction industry.