bluuebunny/crossref_metadata_2025 huggingface dataset:
Prototype of Wearable Glasses for Body Temperature Monitoring for COVID-19 Mitigation
Authors: Hendry J , Sumanto B , Prayoga B T , Budiani R L , Lestari R A , Yuda P P , Nugroho A A
Published: March 2021

Fever is one of the initial presentations that a suspect of COVID-19 might have. Fever is indicated by body temperature higher than normal, which is more than 37.12°C. A thermometer gun is one device that is utilized to measure body temperature. But it requires a short line-of-sight distance between the device and the subjects (< 30 cm). In public facilities like shops, malls, schools, colleges, hospitals, and airports, the device’s use can initiate crowded or queue that higher the COVID-19 infection potential. In this research, wearable glasses is designed to replace such device. The prototype was built to display the thermal-map and body temperature of a single suspect. It can measure body temperature up to 2.5 meters. Based on the evaluation, the average error was about 0.57°C. Recalling that the used thermal array sensor’s inaccuracy is ±2.5°C, then the prototyping has a high potential for further use.
Design SEPIC Converter for Battery Charging Using Solar Panel
Authors: Putri B R , Sudiharto I , Ferdiansyah I , Karso A B , Yanaratri D S
Published: March 2021

Indonesia is a tropical country and has a great potential in alternative source of solar energy. Solar energy is friendly for environmentally because it does not make pollution and is renewable energy. Using solar energy can reduce fossil energy which is this energy can’t be renewed and if used continuously it will be used up. Sunlight is solar energy that can convert the light energy into electrical energy by using solar panels. This paper presents details the design of the SEPIC Converter to Supply Electrical Energy to a Smart Lamp with Solar Energy. Sunlight energy is not always in maximum condition, so to maximize the power produced by solar panels are needed a control system to maximize the output power of converter. This experiment use 2 solar panels, each of 100 WP and arranged in parallel. The control system use PI control. The function is to generate the output voltage for battery charging. Time response of PI control is 0.6 s to according to the set point value of 14 volt for battery charging with the battery capacity is 20 Ah 12 volt. Cohen Coon method is used to find the PI control parameter. So using PI control with Cohen Coon method can make battery charging according to the set point even though solar panels has shading.
Inner Join Query Performance: MariaDB vs PostgreSQL
Authors: Hairah U , Budiman E
Published: March 2021

Research to test the performance of inner joint queries between MariaDB and the PostgreSQL database management system. Inner joint queries have the same output in MariaDB and PostgreSQL DBMS. This study aims to provide a comparative analysis of the response time performance of MariaDB and PostgreSQL databases in the use of inner join queries. The research test was conducted with 1,050,000 records using 21 response time data collection scenarios ranging from 50,000 data to 1,050,000 data collection with multiples of 50,000 data. The PostgreSQL DBMS was found to have better response times than MariaDB in all test scenarios. The results of the regression analysis to test the effect of using the F-test show that there is a significant effect on the amount of data and the relationship together on the response time in MariaDB and PostgreSQL. Then the T-test is carried out to strengthen the results of the study that PostgreSQL has a faster response time than MariaDB, testing 1 combined relationship shows a significant difference, testing 2 combined relationships shows a significant difference and testing 3 combined relationships shows a significant difference.
TEGAR: Tempe Freshness Determination on Mobile Application
Authors: Permana A A , Perdana A T , Riadhi R
Published: March 2021

This research proposes Tempe Segar ‘TEGAR’ as mobile application for freshness determination of tempe based on tempe image on the Android operating system. Three kinds of freshness, including very good, good and not good were used to categorized tempe freshness. In this research, we used 50 tempe samples that were consisted of 25 tempe with plastic wrap and 25 tempe with leaf wrap. Tempe image was taken using mobile phone camera as digital tempe image then extracted using Local Binary Pattern (LBP). Detection accuracy and consumer satisfaction of TEGAR application were evaluated using questionnaire. The evaluation results show that TEGAR application is promising application to determine tempe freshness. TEGAR application will help consumer to determine tempe freshness as an important indicator of good quality tempe. The freshness of food directly or indirectly will affect the health of consumer.
The effect of the internet during COVID-19 on work using the manova algorithm
Authors: Nurhayati A
Published: March 2021

This study aims to find information about the major impact of the internet sites frequented by university alumni on the fate of those who are fast finding jobs and those who have not found work during the COVID-19 pandemic. This research uses a field survey method of university graduates, both those who have found jobs and those who have not. This study uses the manova algorithm with a GLM approach. The results of this study indicate that there is a very large impact on the types of internet sites that are most visited by people who are already working with people who have not worked. This research is only conducted in big cities and can be used to awaken the awareness of university alumni to find jobs more quickly by paying attention to their priorities every time they use the internet.
Sustainable alternative futures for agriculture in India—the energy, emissions, and resource implications
Authors: Ashok Kaveri , Natarajan Ramya , Kumar Poornima , Sharma Kabir , Mathur Mihir
Published: March 2021

India’s falling aquifer levels, erratic monsoons, arable land constraints, stagnating crop yields, growing food demand, and rising greenhouse gas (GHG) emissions necessitate that strategic interventions be planned and implemented to maintain food security in the country. In this paper, we present two novel system dynamics simulation models—termed ‘Sustainable Alternative Futures for India’ (SAFARI) and SAFARI-R (a regionally disaggregated version of SAFARI)—that can be used to develop and analyse specific interventions required at the national and regional levels to sustainably maintain food security. Our simulation results show that increasing micro-irrigation coverage, limiting sugarcane cultivation, and improving water recycling in domestic and industrial sectors can help achieve food production sufficiency within the limitations posed by the availability of natural resources. Alternatively, a behavioural shift towards eating (and cultivating) coarse cereals instead of rice (which is water intensive) is another effective intervention, especially when combined with micro-irrigation or crop yield improvements, and reduced sugarcane cultivation. When compared to a scenario where current practices continue, these alternative pathways to food security can reduce annual water consumption for irrigation by 18%–24%, electricity demand for irrigation by 60%–65%, and the agriculture sector’s total (direct + indirect) GHG emissions by 17%–25%, by 2050. Further, simulations on SAFARI-R indicate that the north, centre, and west zones of the country are considerably pressed for water, while the south and east zones could run out of land. As a way to meet the food demand in these zones in future, the possibility of crop redistribution is explored along with other strategies such as reducing groundwater dependence.
Divergent responses of ecosystem water use efficiency to drought timing over Northern Eurasia
Authors: Huang Mengtian , Zhai Panmao , Piao Shilong
Published: March 2021

Warming has resulted in increases in frequency, intensity and/or duration of droughts in most land regions over the globe. Nevertheless, knowledge on how ecosystem water use efficiency (WUE) responds to extreme drought stress and whether the responses are affected by drought timing is still limited. In this study, we examined the changes in ecosystem WUE under extreme drought years over Northern Eurasia during 1982–2011 and further assessed WUE responses to droughts with separate groupings designed to characterize the timing of extreme drought stress. We found that drought timing indeed influenced the responses of ecosystem WUE under extreme drought years. Negative impacts of extreme drought stress during the dry season on ecosystem WUE were more remarkable than those from extreme drought stress during the wet season. Particularly, impacts of droughts on ecosystem carbon–water interactions differed among ecosystem types due to the specific hydrothermal condition of each biome. The information provided by our analyses plays an importance role in identifying water use strategies of terrestrial vegetation in response to drought stress and will help improve our understanding and predictions of the response of ecosystem WUE to global environmental change.
Developing Small Dual-Fuel Diesel Engine to Control Marine Pollution by Reducing NOx Emission for Application in Fishing Vessels
Authors: Santoso A , Semin  , Cahyono B , Sampurno B
Published: March 2021

Using natural gas for fueling a ship growing extensively since environmental issues become one of the priorities in the shipping industry. The ship uses natural gas as the main fuel commonly called as a gas-powered ship. Gas has lower specific prices compare with any type of diesel fuel. But due to handling, storage, and distribution costs then gas prices for ships become higher even still a bit cheaper than diesel fuels. Besides prices, technically gas is cleaner so it may give the lower emission levels. Dual fuel technology is the best choice in occupied gas as ship fuel due to the existence of the IGF Code. Established Dual-fuel diesel engine is very expensive and available for big power capacity. This research develops a small dual-fuel diesel engine from a conventional engine with power less than 10 HP. The piston crown is a part of the engine that was modified so that the engine can use natural gas in the best performances as the conventional one. NOx as the most hazard emission in the diesel combustion process is controlled to be as the lowest as possible. The quality of air may be significantly affected by those small engine pollutions because of the large number of vessels in that dense environment in the typical fishery villages. In conclusion, the modified dual-fuel diesel engine capable of reducing NOx emission by up to 31% at a practical safe operation of 50% dual-fuel. The higher gas portion gives a lower NOx emission level.
The Estimation of Hourly Solar Radiation on tilted Surfaces using Artificial Neural Network: A Case Study of Surabaya
Authors: Kurniawan A , Masroeri A A , Koenhardono E S , Kusuma I R , Prananda J , Sarwito S
Published: March 2021

This study aims to generate an accurate model for estimating the radiation of solar panels on different inclination angles. The output of this model is useful for determining the optimal installation angle of the solar panel either on land or on the ships. Furthermore, the amount of the hourly direct and diffuse radiation on the horizontal surface is estimated using Artificial Neural Networks (ANN), which were trained with the monthly radiation data of Surabaya from 2018 to 2019. Subsequently, the radiation on the inclined surface is estimated using a mathematical model. Also, the ANN accuracy was validated with a regression value higher than 99% for either direct or diffuse radiation estimate. A full-year evaluation based on the proposed model suggests an inclination angle of 25° for the solar panel installed in Surabaya. Meanwhile, the evaluation gives different angles for each month with the advantage compared with the fixed angle installation.
Detection of Trend Behaviour of Extreme Rainfall Over Java Using Mann-Kendall
Authors: Suroso  , Ghifari Izac Aqsha , Santoso Purwanto Bekti
Published: March 2021

The purpose of this research is to detect the areas that are impacted by climate change in Java Indonesia by creating a model that analyzes the trend of extreme rainfall distribution for the last 42 years. Man Kendal test is used to analyze the rainfall trend behaviour that will determine the happening of climate change or not in that area. The result of this research gave information that several places in Java might be impacted by climate change. This result is crucial to use as an early warning of areas that are sensitive to natural disasters that are most likely caused by climate change like a flood.
Modelling of Unidirectional Oscillating Buoy Wave Energy Converter Based on Direct Mechanical Drive System Under Irregular Wave
Authors: Ariefianto Rizki Mendung , Hadiwidodo Yoyok Setyo , Rahmawati Shade
Published: March 2021

The development of wave energy converters (WEC) is increasing over time with various designs. The need for a WEC design that emphasizes the level of simplicity, portability, and closeness of its implementation to the nearshore is quite interesting to discuss. One of the WECs that can meet these criteria is oscillating buoy based on a direct mechanical drive system. This research proposes the concept of oscillating buoy WEC based on a direct mechanical drive system, which is designed with a unidirectional gear system to be able to generate energy both in the upward and downward wave phases. The WEC is also making to produce high rotation on the output side from the small motion of the buoy, especially in the heave direction. Predicting the power generated by this concept is very interesting because up to now, there has not been sufficient analytical model to estimate the power generated by oscillating buoys WEC based on a direct mechanical drive system, especially under irregular waves. In this work, an analytical method is conducting to describe the interaction between the model and irregular waves from the JONSWAP model. Model interaction is simulating numerically using the MATLAB program. The buoy translational motion of the model in the heave direction, which is converting to electric power by increasing the rotation of the gearbox and the energy stored in the flywheel, can produce significant output power. In the future, the proposed model can be used to develop more feasible and efficient models of wave energy converters.
Utilization The Ship Main Engine Cooling Water for Micro hydro Power Plants Design
Authors: Faturachman Danny , Pujiastuti Endang Tri , Fridolini
Published: March 2021

Renewable energy is non-fossil energy derived from the nature and sustainable, also if properly managed, resources are depleted. The utilization of cooling water disposal on his boat as an energy-producing environment-friendly, by making use of the cooling water flow pressure machine ships as water turbine impeller assembled in such a way so it can generate electricity. Commercial ships usually have large size machines and most use large-capacity cooling system, so the cooling water flow capacity will be even greater as well. This prompted the opportunity to create an instrument for utilizing renewable energy flow of cooling water disposed in vain to rotate the propeller has been drafted into a micro hydro. And expected results can help reduce the workload of the auxiliary engines which will also have an impact on the reduction of fuel consumption. Fluid which flowed by the pump-the pump will rotate the intended water turbine that will generate electrical energy. When the ship sail, the lighting definitely need in each room, by using the electrical energy produced by the auxiliary engine, this water turbine can be applied then the fuel that had been used or consumed by the auxiliary engine can be replaced by the electric energy generated by the water turbines for light ships.
Mapping Oil Spill Using Sentinel-1: Study Case of Karawang Oil Spill
Authors: Sari Dian Puspita , Mukhtasor  , Zikra Muhammad
Published: March 2021

Indonesia as a maritime country has many challenges in developing and making innovations in the marine sector. One of the challenges for Indonesia is how to respond to oil spill disasters that occur because of various events such as blow-out on oil platforms, ship collisions, pipeline leaks, and so on. In the end, marine and coastal pollution cannot be avoided. Karawang is one of the productive northern coastal areas of Java Island with various facilities such as single point mooring, oil wells, tourist areas and historical heritage. On July 15, 2019, an oil-well belonging to Pertamina Hulu Energi (PHE) ONWJ had leaked and polluted the sea and coast not only in Karawang, but also spread to Jakarta waters. As a result of this leakage, of course the impact is very large and varied from ecological, social and economic aspects. In this paper, an oil spill mapping will be carried out to determine the affected areas using sentinel-1 data. Data processing is assisted by open-source software SNAP (Sentinel Application Platform). As the result, August 19, 2019, oil spill seen in Bekasi area. So that oil slick move from Karawang to the west. This oil spill map area can be used in many ways such as clean-up strategy, calculating amount of dispersant, and many more.
Temporal and Spatial Analysis of Mangrove Forest Change in the North Coast of East Java
Authors: Wardhani A K , Zikra M
Published: March 2021

The north coast of East Java has high human activities and needs. These human needs include opening new land for housing areas, so that some mangrove areas have begun to be converted into residential areas. This can directly cause ecological impacts that threaten the sustainability of the coastal environment, but on the other hand, mangrove areas on the north coast of East Java are also developed as conservation and tourism areas. The purpose of this study is to determine changes in mangrove area and changes in coastlines in the northern coastal region of East Java during the period 2013 to 2019 based on Geographical Information Systems (GIS) using the Supervised-Maximum Likelihood image classification method. The results of this study showed that the largest change in mangrove forest area was in Sidoarjo Regency by 95%, while the lowest change in mangrove forest area was in Tuban Regency at 7.20%.
Modeling of Sediment Distribution and Changes of Morphology in Estuary Flow Kapuas River, West Kalimantan
Authors: Catherine L A , Pratikto W A , Suntoyo
Published: March 2021

Pontianak Dwikora Port is a port that has been owned by Pontianak City since the Dutch colonial era and has been used as a trade center to export and import goods needed by West Kalimantan Province. Dwikora Port is located inside the Kapuas Kecil River and under the auspices of PT Pelabuhan Indonesia II (PELINDO II). Due to the location of the port in the river, the shipping channel is often disrupted due to silting (sedimentation) at the river mouth. So that the ships do not run aground, periodic dredging is carried out. This is to find out how much sediment is in the estuary. So, this study continues previous research by performing numerical modeling using Mike 21 software [1] to determine the sediment distribution flow patterns that affect silting that occurs in the Kapuas Kecil River Estuary. The data to be used are tidal data from field measurements, wind data from BMKG, wave generation data, river discharge, and TSS from previous research journals. The TSS used is derived from the river with the maximum taken from previous studies, namely 0.63 gr / L. The result is that the flow pattern of sediment distribution is strongly influenced by the confluence of flow patterns from rivers and sea. Sediment originating from the river slows down at the estuary as a result of the width of the river and is held back by waves from the sea, coupled with the tidal effect that occurs, the sediment oscillates and settles on the bottom of the mouth of the Kapuas Kecil River, causing changes in the basic morphology of the estuary.
Tsunami Wave Transformation in Selesung Bay (Lampung)
Authors: Gelfi Mustarakh , Kencana Elsa Rizkiya , Achiari Hendra
Published: March 2021

The 2018 Sunda Strait tsunami is categorized as a volcano tsunami that happens due to Mount Anak Krakatau’s flank collapse. The modeling effort with this kind of tsunami is challenging. Selesung bay is located in Legundi Island, one of the suffered islands from the tsunami in the Krakatoa water area. This research tries to do a local scale simulation of the bay’s tsunami waves using shallow water wave simulation software. The model permits wave transformation simulation in the bay from the offshore side to the coastal point. The result presents that the inundation height of the tsunami in Selesung bay is a combination of wave height (1.5 m), water depth (1.65 m), and wave set-up (0.2 m). Those properties are summing up 3.4 m modeled inundation height, which is committing to less than 1% error from the measured data of 3.38 m. The model also gives an insight into the diffracted wave condition in Selesung bay with a wave height of 2.8 m and a wave period of up to 25 s. All in all, the model shows a good agreement with measured data and permits the benchmarking points for further study.
Technical Analysis of Diesel Engine Convert to Dual Fuel Engine for the Ship
Authors: Semin  , Cahyono B , Kusuma I R
Published: March 2021

Fossil fuel is the high-cost price. This trend of price is increasing and not stable. For the future is need alternative low cost and stable price fuel. Natural gas has low cost and stable price for alternative fuel. The objective of this paper is to analyze the effect of diesel engine converted to dual fuel engines using. The method of this paper is a mixture of HSD with CNG conducted on the ship diesel engine. The conversion is determining additional components required. Then, the reduction of the cargo for two cars for cylinder placement used. After the engine has been changed to dual fuel, the performance investigated. The performance investigation is based on the variation of HSD and CNG fuel composition in the engine. The result has shown that the best performance is when the 30: 70 of CNG: HSD mixture composition.
An Experimental Study on Hydraulic Model of Water Intake Canal at Steam and Gas Power Plants
Authors: Suntoyo  , Muslim Taufiq Wibawa , Wicaksana Febrian Tegar , Rahmawati Shade , Silvianita
Published: March 2021

The performance of the canal water intake used in the Gas and Steam Power Plant (PLTGU) cooling system is carried out by testing the physical model of the water intake canal with a 1:15 scale model. In which, the canal water intake prototype has dimensions of length, L = 33.30 m, width, B = 13.40 m and height, T = 11.67 m, scaling the prototype dimensions to the model dimensions is done by complying with Froude’s law. The purpose of this paper is to determine the flow patterns that occur in the physical model and the minimum elevation allowed based on applicable guidelines [1]. The variables measured in this study were the flow velocity in the canal and also the visual documentation of the flow pattern in the canal including the formation of vortices. Tests were carried out on three variations of tidal elevation, namely HWL, MSL and LWL. The experimental results show that the flow pattern in the channel varies with depth with an average Reynolds Number value = 3.5 × 104. Vortex formation occurs at all elevations where the vortex is formed in the area near the pump. The observations show that the critical elevation of the canal is at H = 0.29 m for the model and H = 4.35 m for the prototype.
Hydrodynamic Properties of a Moored Floating Breakwater using CFD Approach
Authors: Abdullah S.F. , Fitriadhy A. , Mohd M.H. , Rahman M.A.A. , Suntoyo  , Kurniawan A. , Pratikto W.
Published: March 2021

In presence of complex-hydrodynamic interaction between water wave and moving structure, a reliable method that can analyse nonlinear phenomena is necessarily required. This paper presents numerical investigation of a moored floating breakwater using computational fluid dynamic (CFD) approach. The mathematical model is based on the extended Reynolds Average Navier-Stokes (RANS) solver for solid-porous obstacle. A high amplitude wave with several wave periods were deliberately considered in the simulation to allow nonlinear wave effects on the floating structure such as wave breaking, overtopping, including viscous friction. Here, the two fluid calculation method for interface boundary between water and air is proposed to capture the complex free surface changes. In addition, the fractional average volume obstacle representation (FAVOR) using partial cell treatment method is employed to simulate the motion of breakwater boundary on the free surface. Approximations and validations on the hydrodynamic properties of the structure have been carried out which include wave transmission coefficient, sway, heave, pitch, and mooring forces. The results show that the CFD model can fairly simulate well on hydrodynamics of the floating breakwater. The discrepancies between numerical and experimental data can be partly attributed to the nonlinearity in the incident wave definition.
Analysis of Leading Edge Protuberances on Fully Submerged Hydrofoil of 15 m Pilot Boat
Authors: Chrismianto D , Santosa AWB , Wirahutama A
Published: March 2021

Resistance greatly affects on selection of the main engine and ship fuel consumption. To achieve the speed of the ship, the ship must be prepared to overcome resistance in the waters to be passed by choosing the right engine according to the needs of the ship. In the last few years there have been many studies on biomimetics or the use of systems in nature to be applied in a technology. Such as the use of Leading edge protuberances. Despite its large size and stiff flexibility, the humpback whale has a good maneuver even when chasing prey compared to other animals of its size. This study aims to obtain the highest lift force result and the smallest resistance with a hydrofoil model configuration of leading edge protuberances which resembles a humpback whale fin (megaptra novaengliae). The Computational Fluid Dynamics (CFD) is applied to analyse lift faorce and ship resistance of all models variation. The results indicates that from all variation of models at the Fn 1.356, the model has 5 ° angle of attack were able to reduce the total resistance value of Pilot Boat by 35.13%.
The Effect of Additional Subsea Floater on Mooring Line Tension and Motion of CBM (Conventional Buoy Mooring) Ø 4.5 m
Authors: Mursid O , Malau K R , Huda N , Abidin A M A , Sutarno G
Published: March 2021

Single point mooring of Conventional Buoy Mooring (CBM) is an offshore mooring structure where the mooring line attached from bow of ship to CBM. Lack buoyancy on CBM needed Additional subsea floaters to increase buoyancy of CBM. Time domain simulation on Moses software version 11 used to calculate the effect of the variation number of subsea floaters to chain tension and CBM Motion. The result is a single configuration subsea floater has higher tension and extreme motion than multiple configuration subsea floaters.
Identification of Free Span on Underwater Pipeline using Side Scan Sonar and Dual-head Scanning Profiler
Authors: Pratomo Danar G , Khomsin  , Harlambang P L
Published: March 2021

Indonesia is a country that has an important role in the oil and gas industry. Considering this important role, it is necessary to conduct an inspection and safety inspection to support the sustainability of the oil and gas industry in Indonesia.. In this study the method used is the processing of side scan sonar (SSS) and dual-head scanning profiler (DHSP) data obtained from PT. Pageo Utama. Side scan sonar data is used as a visual representation of the pipeline while dual-head scanning profiler data is used to obtain the topography of the sea and surrounding pipes to identify the dimensions of the free span. The result of this study shows 47 free spans from a 6.8 km underwater pipeline. Free span with the longest dimension is FS-43, with length of 42.109 m and height of 0.44 m, which is located at KP 6.045. Free Span with the highest dimension is FS-45, with height of 1.22 m and length of 20.329 m, which is located at KP 6.465.
Methane Emissions Evaluation on Natural Gas/Diesel Dual-Fuel Engine during Scavenging Process
Authors: Felayati F M , Semin  , Cahyono B
Published: March 2021

Natural gas/diesel dual-fuel engine is known as a solution for shipping industries to simultaneous reduces NOx and PM emissions nowadays. Unfortunately, high HC emissions are produced, especially at low loads conditions. However, there are two possibilities for the source of HC emissions from the engine, namely during the combustion process and during the scavenging process. This study evaluates the methane emissions (part of HC emissions) concentration during the scavenging process. Cold flow engine simulations are evaluated and validated to this study at low load condition using natural gas injection at intake port during valve overlap. Moreover, several natural gas injection timings are conducted to observe the effect on the methane emissions concentrations at exhaust port after the exhaust valve closed. The natural gas penetration is nearly after the intake valve closed (IVC) thus the natural gas enters the combustion chamber at the next intake cycle. It observed that the scavenging process contributes to the methane emissions formation on natural gas/diesel dual-fuel engine using intake port natural gas penetration after IVC. Besides, the concentration of methane emissions during the scavenging process has very low contribution than the combustion process. It is possibly a variation of the methane emissions concentration in the other valve lift profile and natural gas injection strategies. Thus, it recommends to widely observing how significant the methane emissions generated during the scavenging process on the other engines with those variations.
Conceptual design of the LNG dual-fuel system for harbour tug towards Indonesia Greenport
Authors: Fathallah A Z M , Ariana I M , Putra G H , Ma’ruf B
Published: March 2021

Declaration of several large ports as Greenport indicates that increasing the environmental concern of port operatio n in Indonesia. Harbour tug as one of the port’s operational supports is also required to contribute low emissions. One method to reduce exhaust emissions from tugboats is to replace the use of fuel oil with natural gas. This study describes the conceptual design of a dual-fuel LNG system at the harbour tug vessel for operational needs at the Indonesian port. The 2x2500 HP Harbour Tug, which is the case in this study, uses a dual fuel diesel engine as a prime mover with a direct mechanical propulsion system. Study optimization considering the operational mode of a prime mover will determine the LNG storage capacity, due to harbour tug vessel operation and space capacity as well as of bunkering system. The design parameters for the main components of the fuel system, such as the Regasification Unit, Gas Valve Unit are essential considerations to support the system’s operation optimally.
Study of shoreline evolution under the influence of jetty construction: A case study of Karangsong Beach, Indramayu, Indonesia
Authors: Abdurrahman U , Park H , Suprijo T
Published: March 2021

Karangsong Beach, Indramayu located on the north coast of Java Island of Indonesia has been an important traditional small downstream river port for the fishermen who live in the Indramayu District area. This traditional port has been rehabilitated by construction of jetty in the period 2005 to 2007. The jetty construction affected coastal process, which was previously dominated by erosion turned into dominated by accretion. This study examines the process of shoreline evolution by calculating the sediment transport rate and analyzing the shoreline changes. The analysis began by extracting shoreline data from Google Earth images to provide a historical database of shoreline. The coastal process was then simulated using the coastline model Uniform Beach Sediment Transport Coastline (UNIBEST-CL) with waves and the longshore component of tidal currents as input and also calibrated using the shoreline database. The calibrated model was employed to simulate the annual conditions over a nine-year period, 2008-2017. The results show the sediment transport rate is dominated by the southeast direction. There is a significant difference in coastal processes between northern and southern regions, which is due to the presence of jetty. In the northern region, the sediment transport rate was blocked by the jetty so that this region is accreted. In the southern region, the supply of sediment from the north replaced by sediment supply from the river causes accretion yet smaller than the northern region.
Variation of Seasonal Monsoon Wave-Driven Circulation Pattern in the Lee of Groyne in Kuala Nerus beach
Authors: Zulfakar M S Z , Ariffin E H , Akhir M F , Awang N A
Published: March 2021

Terengganu coast tend to dual monsoonal as presenting Northeast Monsoon (NEM) as a storm season and Southwest Monsoon (SWM) as a calm season. The area of interest is a groyne in Kuala Nerus, Terengganu on east part of Peninsular Malaysia. The use of numerical model was performed on the dual monsoon seasons with MIKE 21 modules (Spectral Wave FM and Flow Model Hydrodynamic FM modules). Two numerical model were set up according to the two season. The resulting model indicates, the current circulation pattern consisted of persistent eddy re-circulation in the lee of the groyne during both season. As the longshore current directed into the groyne, it deflected offshore resulting in rip current along the groyne. The rip current and incoming wave converge at the tip of the groyne and flow parallel to coastline before being projected onshore performing a re-circulation cell. During NEM, the model shows a clockwise re-circulation cell and counter-clockwise formation during SWM. The formation of the rip current and eddy circulation is associated with erosion event as the sediment transported offshore causing sediment shortage on the adjacent shore. The importance of this study can be a reference to any development of coastal defense monsoon dominated environment.
Hybrid Photovoltaic-Thermal Solar System for Brackish Water Reverse Osmosis
Authors: Fitri Sutopo Purwono , Baheramsyah Alam , Santoso Agoes , Santoso Yudhi Satrio
Published: March 2021

In this paper, a hybrid combination of solar thermal collector and photovoltaic (PV) solar system was applied to reverse osmosis (RO) desalination plant to increase the energy efficiency and its sustainability. An experimental study was performed on 75 GPD small scale RO plant using processed brackish/saline groundwater in Kenjeran area. It shows that increasing in temperature of feed raw water results a decrease in pump pressure and the consumption of electrical power. The smallest result of pump pressure which is 40 psi and the smallest electrical power consumption which is 1.68 W were obtained when the temperature is at 40 °C. However, the quality of the product, the amount of water, and the ability of the membrane to recover salt are decreasing when the temperature of the feed water is raised. The best result was obtained at 31 °C with a TDS water product quality of 105 ppm, the amount of produced water was 36.5 L, and a salt rejection ability was 95.9%. The electrical power consumption of whole system for one day was 914.63 Watt-hours and requires six units of 155 Watt-peak capacity of PV panels.
The Study of Coastline Changing and Total Suspended Solid Distribution Based on The Remote Sensing Data in Teluk Lamong Multipurpose Port Terminal
Authors: Pratikto Widi Agoes , Fitriadhy Ahmad , Maulana Muhammad Ilham , Huda Abiyani Choirul , Putri Destyariani Liana , Simatupang Liany Ayu , Wahyudi Nazariano Rahman , Laksono Rendatiyarso , Dewi Anggie Vibriyanti Rossari
Published: March 2021

Looking forward to the abovementioned conditions, this research is needed to elaborate on the effects of the reclamation to the marine resources in Teluk Lamong Multipurpose Port Terminal as the reclaimed product. In order to describe the impact of the port development, this study will analyze the shoreline changing, the current pattern modeling, as well as the Total Suspended Solid (TSS) modeling using the remote sensing data. The several numbers of expected objectives through this study are to get the set of scientific information on the shoreline changing in Teluk Lamong Multipurpose Port Terminal in the year of 2012 and 2020, to get the figure of current pattern in Teluk Lamong Multipurpose Port Terminal in the year of 2012 and 2020, and to elaborate TSS concentration through the modeling approach in Teluk Lamong Multipurpose Port Terminal in the year of 2012 and 2020. Hence, there is a set of methodologies and tools to cooperate with the information before and after the reclamation. The use of the Digital Shoreline Analysis System (DSAS) software to analyze coastline conditions. The using of Mike 21 to analyze the current pattern and TSS concentrations. In addition to the TSS analysis, it will also need a set of remote sensing data from the Google Earth Engine (GEE). The modeling and calculation give information about the End Point Rate (EPR) values and TSS values. The EPR values are 107.5 m/year, 59,625 m/year and 10,375 m / year. The TSS values are 0-20 mg/L, 20.1-40 mg/L, 40.1-80 mg/L, 80.1-120 mg/L and >120.1 mg/L. Moreover, the result shows the different values among the length of coastline, the current pattern, and TTS in the years 2012 and 2020. The difference in the coastline reaches 950 m at this latest 8 years. While it also brings the changing to the current pattern and sediment transport which show through its current velocity and sediment content per liter of seawater during high and low tide accordingly.
Mesh Planning Optimization for Urban Distribution Network with High Reliability
Authors: Zhou Y J , Ding H , Shi T Q , Fang R C , Wang Y W , Bie F M
Published: March 2021

Modern distribution network has a huge volume and a wide range of points, so the difficulty of construction and transformation of distribution network often lies not in technological innovation, but in the operability of planning scheme, adaptability and flexibility of network structure. Therefore, an optimization model of mesh planning for high reliability power supply in urban power grid is proposed. Firstly, the planning process is optimized to avoid the cyclic adjustment of power supply mesh and power supply unit division. Secondly, a target network architecture and power supply unit partition model for medium-voltage power grid are proposed, which can meet the double power demand of important power users and ensure no cross-supply between units. Finally, an example of mesh planning in a city center in Hubei Province of China is given, and the application of the optimization method is described in detail. The results show that the method is easy to carry out, and effectively improves the reliability of power supply in urban power grid.
Development and Application of Real-Time Online Monitoring System for Long Transportation of Large Power Transformer
Authors: Zhou H B , Zhang Z X , Xie Z X , Li W T , Zhou Z C
Published: March 2021

A set of transportation process monitoring system for large power transformer transportation is developed, including transportation state intelligent acquisition terminal, monitoring system platform software and mobile app. The effectiveness of the system is verified in the actual transportation monitoring of converter transformer. It solves a series of problems existing in traditional methods, ensures the transportation safety of large electric power equipment and reduces the investment.
Experimental Investigation on Water Droplet Impacting Liquid Film on Inclined Wetted Surface
Authors: Chen J J , Liu Q F , Zhang F , Zhao F L , Qu J Y
Published: March 2021

The secondary carry-over of the droplet and liquid film in the steam-water separator can influence the separation efficiency of the separator. The generation of the secondary droplets resulting from droplets impacting the water film of the wetted surface is one of the mechanisms of secondary carry-over. Therefore, the experimental investigation on water droplet impacting liquid film on inclined wetted surface is conducted through high-speed video camera. The subsequent form and evolution process once the droplet colliding with the inclined liquid film are obtained. The droplet splashing phenomenon and mechanism are explained. The qualitative analysis of influence of the initial droplet diameter, velocity and the inclination angle of the wet surface on the splashing behavior is conducted. The results reveal that with increasing angle of inclination of the wet surface, the critical velocity to generate the splashing phenomenon increases accordingly; the increasing initial droplet diameter leads to decreasing critical velocity; the splashing phenomenon is more likely to appear in cases with higher impacting velocity, larger initial droplet diameter and smaller inclination angle, under which conditions the number of secondary droplets generated increases and the splashing phenomenon is more obvious. The obtained experimental results are significant to the study of steam-water separation and can lay basis on design of the separator.
An Efficient Short-Term Electricity Forecasting Approach Based on EEMD-LSTM Model with Feature Factors
Authors: Tian Y J , Luo J R , Wen M , Li J G
Published: March 2021

The forecasting of electricity consumption data plays an important role in the operation, planning, and security of the power grid. However, electricity data is affected by multiple factors and large fluctuations, which makes it difficult to accurately forecast. Traditionally, ARIMA and SVM are widely used for electricity forecasting based on historical consumption data. However, for non-stationary multi-feature data, traditional schemes cannot achieve deep feature mining of them, and the forecast results are inaccurate. To address this problem, this paper proposes an efficient short-term electricity forecasting approach based on EEMD-LSTM model. Firstly, we perform Savitzky-golay (SG) smoothing on the original data, and then introduce feature factors to the feature analysis. In particular, the proposed approach can reduce the random noise in data, as well as reduce the impact of data fluctuations, and effectively learn the long-term characteristics of the data. The simulation results show that, compared with ARIMA, LSTM, EMD-SVM, EMD-LSTM, the proposed approach can achieve better accuracy in the electricity forecasting.
A Design of Three-level Inverter Based on PCI Control
Authors: Qu L M , Wang C , Zhang H D , Lin Y
Published: March 2021

To solve the problem that the PI-controlled three-level inverter can’t achieve zero steady-state error on AC, a closed-loop control scheme using the PCI controller is proposed. The voltage and current double closed-loop control scheme is adopted. The circuit of diode-clamped three-level inverter is selected as the controlled object. And the PCI controller is designed. The zero steady-state error of three-level inverter based on the PCI control is analyzed in detail. Finally, the closed-loop control system of three-level inverter is simulated on the MATLAB/Simulink platform. The results show that the PCI control has good dynamic response ability and can accurately track various sudden loads. And then the correctness of theoretical analysis is verified.
Research on High Power Ultrasonic Power Supply Based on Cascaded 9 Level Technology
Authors: Zhou C H , Zhang C Z , Zhang W Y , Tian Y , Wang C R , Shu Y H
Published: March 2021

In view of the low output power and high power density of ultrasonic power supply, a high power ultrasonic power supply based on 9-level inverter technology is proposed. The inverter of the power supply consists of two H-bridge units cascaded to form a 9-level converter, which outputs the 9-level voltage waveform, which can significantly improve the output power of the ultrasonic power supply, reduce the inductance of the matching network, and reduce the power density of the ultrasonic wave. The phase difference method based on PI control is used to track the resonance frequency. By analyzing the system structure, working principle and control strategy of the ultrasonic power supply, modeling and simulation were conducted on Matlab/Simulink to verify the feasibility and effectiveness of the scheme.
Study of Thermal Supply Mode of Floating Nuclear Power Plant in Offshore Oil and Gas Fields
Authors: Zou S F , Gong D X , Song J , Zhao J , Zhang X H
Published: March 2021

The floating nuclear power plant (FNPP) is a solution to the thermal supply in offshore oil and gas fields, including the applications in thermal recovery and flow assurance. The output power of marine reactors under development in China matches the thermal demand of offshore oil fields. In order to analyse the thermal supply mode, the following aspects are investigated: the application scenarios, the thermal loss of the thermal supply pipeline, and the selection of platform type. Then, a case study is presented to illustrate the applicability of FNPP in the Bohai Sea for the enhancement of oil recovery. The case shows that the current solution works well with the offshore marginal oil field. The future solution is also discussed as to further improve the economy of FNPP.
Experimental Study on the Effect of Phase Change Material Melting Point on TG/PCM Thermal Control Properties
Authors: Xiao L X , He Y T , Wang J Q
Published: March 2021

Three composite phase change materials (PCM) with peak melting points of 42°C, 50°C and 58°C were prepared using different mass fractions of stearic acid (SA) and lauric acid (LA). A thermal control model structure of thermoelectric generation/PCM (TG/PCM) was designed using PCM, and analyzed for its internal thermal conversion, transmission and storage mechanisms. In addition, TG/PCM experimental prototypes with PCM melting points at 42°C, 50°C and 58°C were designed and tested for their temperature control properties and output power. The results showed that under PCM melting points of 42°C, 50°C and 58°C, temperature difference between the cold and hot end of the TG/PCM prototype thermoelectric battery was maintained above 8°C for 70 minutes, 45 minutes and 27 minutes, respectively. The total energy of system output power above 6mW was 73.9J, 52.4J and 18.9J.
Design and Implementation of an Innovative Series Power Supplies for Solar Unmanned Aerial Vehicles
Authors: Jin Y , Wang X , Ma D , Jin S N
Published: March 2021

Conventional unmanned aerial vehicles power systems only have one MPPT controller to operate. And MPPT controller will be influenced by loss of solar arrays and multiple maximum power points. In this paper, an innovative topology of UAV power system is proposed as well as generating a related MPPT control strategy to keep output voltage increase slowly. Hardware circuit design is presented based on selection of power diode, input filter capacitance, output filter capacitance and parallel diode. A prototype of 1.2kW power supplies is implemented to verify the proposed topology and MPPT control strategies.
Study on a New Method of Determining Boiler Soot-blowing Steam Flow Rate
Authors: Chen H Y , Xue Z H , He X X , Pei D S , Zhangand P F , Sun J F
Published: March 2021

In this paper, a new method of determining boiler soot-blowing steam flow rate was proposed. By this method, three tests of unaccounted-for leakage rate of the unit thermal system should be conducted without soot blowing, and the unaccounted-for leakage ratio difference between arbitrary two tests should be within 0.10%. The average value of three unaccounted-for leakage flow rate test results was used as the final result of unit unaccounted-for leakage flow to determine the flow rate of soot-blowing steam. During the test period of power output and heat rate, the calculation of soot blowing steam flow rate took account of the result of unaccounted-for leakage tests and the water level change of condenser hot well, deaerator and boiler drum.