bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Key Technology of Environmental and Efficient Coal Storage and Loading
Authors: Xiao Yajing , Li Xu , Wu Hui
Published: February 2021

In this paper, the existing problems of coal storage and loading technology are put forward, such as serious environmental pollution, low efficiency and low degree of intelligence. Aiming at these problems, the large capacity closed coal storage technology, intelligent collaborative control technology of storage and transportation equipment, intelligent unmanned rapid quantitative loading technology, intelligent unmanned vehicle dispatching technology, and remote operation and maintenance technology and predictive maintenance technology of storage and loading electromechanical equipment are systematically studied, and the corresponding solutions are proposed. It is of great significance to promote the development of environmental and efficient coal storage and loading technology.
The L(2,1)-Labeling of Planar Graphs with Neither 3-Cycles Nor Intersect 4-Cycles
Authors: Zhou Wenjuan , Sun Lei
Published: February 2021

Given a graph G, a k-L(2,1)-labelling of G is a function c: V(G)→{0,1,2,…,k} such that |ϕ(x)-ϕ(y)| ≥ 2 if x is adjacent to y and |ϕ(x)-ϕ(y)| ≥ 1 if x and y have a common neighbor. The least k denoted by λ
2,1 (G) is the L(2, 1)-labelling number. In this article, we proved that: for every planar graph with neither 3-cycles nor intersect 4-cycles and Δ(G) ≥ 26, λ
2,1 (G) ≤ Δ(G) + 12.
Vibration Law of Vertical Submarine Pipeline Based on Numerical Simulation
Authors: Xu Sui , Miao Xiannan
Published: February 2021

Due to the special working environment of the vertical submarine pipeline, the experimental research is difficult, so this paper makes a numerical simulation study on the turbulence vibration response of the vertical submarine pipeline based on Fluent software. It solves the vibration law of vertical submarine pipeline under different working conditions, and analyzes and discusses the vibration law of the vertical pipeline on the seabed. By establishing the geometric model of the vertical submarine pipeline based on the similarity principle, the flow field distribution law and the vibration law of the vertical submarine pipeline are obtained. When comparing the results of numerical analysis with the experimental results, the selected physical mathematical models are valid, with a margin of error of not more than 10 percent. Therefore, the vibration law and the movement law of the surrounding flow field of the vertical pipeline under different wall thickness, length, incoming flow velocity, different constraints and whether or not to add vibration absorber are analyzed. The results show that the vibration shape of the vertical pipeline is “8” shape under the action of incoming flow.
Study on Detection Image Processing Method of Offshore Cage
Authors: Gao Tianyu , Jin Jun , Xu Xin
Published: February 2021

The paper aims to test the integrity of offshore cages. In this paper, offshore robots are used to collect video images. Through preprocessing methods such as color space conversion and Retinex algorithm of fusion-oriented filtering, the color distortion of the image is improved and the edge information of the image is maintained, so that the collected cage image is better recognized and calculated by the computer. And the paper uses the Canny algorithm to accurately locate the edge of the image, so that the boundary information can be reflected in more detail. In this paper, the adaptive threshold segmentation algorithm combined with mathematical morphology processing method is used to segment the offshore cage image, and extract the skeleton of the decomposed image to realize the detection of the integrity of the offshore net. Finally, a ROV equipped with a camera was used to verify the proposed method in a wave-flow water tank, which confirmed the effectiveness of the method and optimized the integrity recognition and image processing of the cage.
Modeling Analysis and Algorithm Optimization Design of Vehicle Networking Based on Information Transmission
Authors: Liu Yongqiu , Liu Chao
Published: February 2021

Vehicle Internet is the embodiment of mobile self-organizing network in the field of transportation.It is regarded as a key technology to reduce the incidence of traffic accidents, improve traffic efficiency and passenger driving experience. It has become the central development direction of the country. Because it is widely influenced by government industries and universities, the effective transmission of information is the core and problem of automotive Internet. This article starts with the application needs of vehicle Internet, designed to address different security-related needs in messaging and non-secure messaging applications, modeling analysis and algorithm optimization design combined with the network attributes of the vehicle Internet. High-speed mobility of vehicle nodes, self-organization and the existence of multi-hop networks, the information transmission on the vehicle Internet is very different from the traditional mobile AD hoc network, at the same time, with the continuous expansion of in-vehicle application Internet, different application scenarios have different service requirements, different services require the vehicle information system’s Internet to guarantee different modes of transmission. Therefore, this paper studies application-oriented information transmission technology. It improves the efficiency of the entire information transmission system, and it is of great significance to the development of vehicle Internet.
Application of the Stacking and LACP Technology in Communications Networks
Authors: Wang Huarong
Published: February 2021

A key factor that has been winning market competitive advantage by carrier markets is how to solve the selection of equipments with lowest cost which provides a reasonable solution on network security and topology. By introducing the stacking technology, this paper gives a detailed explanation on how to use the lowest cost to solve the equipment selection problem and the devices’ hot backup. As the same time, it is shown that the network link aggregation hot backup is resolved by using the Link Aggregation Control Protocol (LACP). Once there is a failure in both a link and an equipment, the system would detect the failure and automatically switch to the backup link and equipment to ensure the network security.
Global and national assessment of the incidence of asthma in children and adolescents from major sources of ambient NO2
Authors: Chowdhury Sourangsu , Haines Andy , Klingmüller Klaus , Kumar Vinod , Pozzer Andrea , Venkataraman Chandra , Witt Christian , Lelieveld Jos
Published: February 2021

Pediatric asthma incidence has been associated with exposure to nitrogen dioxide (NO2) in ambient air. NO2 is predominantly emitted through fossil fuel use in land transportation, power generation and the burning of solid biofuels in households. We simulated NO2 with a global atmospheric chemistry model, combined with a land use regression model, to estimate NO2 exposure in all countries worldwide. The global asthma incidence among children and adolescents attributable to NO2 was estimated by deriving an exposure-response function from a meta-analysis which included epidemiological studies from multiple countries, baseline incidence rates from the Global Burden of Disease and gridded population data. The sectoral contribution to pediatric asthma from NO2 exposure (NO2-related asthma incidence: NINC) was estimated for different source categories to provide guidance to mitigation policies. We estimate 3.52 (2.1–6.0) million NINC per year globally, being about 14% of the total asthma incidence cases among children and adolescents. We find that emissions from land transportation are the leading contributor to NINC globally (∼44%), followed by the domestic burning of solid fuels (∼10.3%) and power generation from fossil fuels (∼8.7%). Biogenic emissions which are not anthropogenically induced may contribute ∼14% to the total NINC. Our results show large regional differences in source contributions, as the domestic burning of solid fuels is a main contributor to NINC in India and Nepal (∼25%), while emissions from shipping are the leading source in Scandinavian countries (∼40%), for example. While only 5% of all children and adolescents live in areas where NO2 exceeds the WHO annual guideline of 21.25 ppb (40 μg m−3) for NO2, about 90% of the NINC is found in regions that meet the WHO guideline, related to the uneven distribution of children and adolescents in the population. This suggests the need for stricter policies to reduce NO2 exposure, and revisiting the current WHO guideline to reduce the health risks of children and adolescents.
Bottom ash treatment by using seawater with Citrus aurantifolia
Authors: Bain N F , Abidin C Z A , Kamaruzaman W N , Arbaan N S
Published: February 2021

The combustion process of coal from a coal-burning power station in TNB Janamanjung Sdn. Bhd. for production of energy was produced a primary by-product called coal ash. The huge amount of bottom ash was considered harmful to the environment and typically disposed of on-site disposal systems without any further use. The environment can be polluted since the toxic elements such as heavy metals that exist in the ash could pose a danger to public health. To overcome these problems, an effective treatment needs to be done to overcome the problems. The purpose of this research is to study the possibility of developing a new technique to reduce heavy metal elements by using seawater as a washing method and Citrus aurantifolia as leaching methods. A good alternative from the use of citric acid from the Citrus aurantifolia was discovered to be substitute strong acids such as HCl in the leaching process since citric acid can react as an organic acid which fewer negative effects compared to the stronger acid to humans and the environment. The bottom ash was rinsed and soaked in the seawater for 24 hr before the leaching process by using Citrus aurantifolia. The result showed that the heavy metals content such as copper (Cu), zinc (Zn), and arsenic (As) can be decreased after the removal process. In fact, the results show that the heavy metal removal up to 92% for As when the bottom ash was soaked until 72 hr but for Cu and Zn, the removal efficiency higher when the bottom ash was soaked at 20 hr. In conclusion, the optimum time to remove heavy metal from bottom ash by using Citrus aurantifolia was determined but the efficiency differs with the time taken to soak the bottom ash in the acid solution.
Design of photoreactor with high sunlight concentration for improved photocatalytic degradation of dye pollutant
Authors: Yap W Q , Chin Y H , Leong K H , Saravanan P , Sim L C
Published: February 2021

A homemade reactor was designed and fabricated with the use of P25 Degussa TiO2 as the photocatalyst. P25 Degussa nanoparticle is a mixture of 75% anatase and 25% rutile. It is more efficient than pure anatase polymorphs because anatase had a larger band gap. This will increase the useful wavelength range of photoactivity and the also size of the rutile crystal lattice become smaller, thus enhance the photocatalytic reaction. The performance of the homemade reactor was evaluated with a different parameter like the different type of dyes, different dosage, different concentration and compare with the conventional method (beaker). The photolysis of methyl blue (MB), methyl orange (MO) and Rhodamine B (RhB) in the absence of photocatalyst recorded an overall efficiency of 64%, 56%, and 48% respectively. The photodegradation of dyes in the presence of photocatalyst achieved an overall efficiency of 85%, 49%, and 96%, respectively. The overall efficiency can achieve 100% after 2 h of reaction time with 2 g of P25 Degussa. The homemade reactor reached a better degradation rate than that of a conventional method (beaker).
Phosphorus reduction in batch culture using seed sludge of wastewater
Authors: Yusuf M , Kasmuri N , Ahmad R , Santiagoo R , Ramasamy S
Published: February 2021

Phosphorus is a chemical substance and is a kind of nutrient that is essential for the growth of the organism. This key element tends to be growth-limiting-nutrient in lake ecosystems. The high concentration of phosphorus is toxic and can cause a major effect on the water body. Excessive nutrients may lead to eutrophication which will cause the depletion of oxygen. The anoxic waters would reduce the water quality of the surface water and disrupt the stability of the ecosystem. Thus, it is important to measure the phosphorus in a surface water system and to limit the amount of phosphorus going into the water body. Thus, this research aims to evaluate the phosphorus reduction using seed sludge taken from wastewater treatment in Kolej Mawar, UiTM, Shah Alam, Selangor. In the wastewater, biological phosphorus removal (BPR or Bio-P) or the enhanced biological phosphorus removal (EBPR) is the biological process where this substance is incorporated into cell biomass and subsequently removed from the process as a result of sludge wasting. Here, seed sludge from wastewater was used in a batch culture experiment using two different solutions of disodium hydrogen phosphate (Na2HPO4) and di-potassium hydrogen phosphate (K2HPO4) in a synthetic medium. The phosphorus reduction and the percentage removal were observed in these two solutions in one-week incubation time. It can be observed that the percentage removal of phosphorus in Na2HPO4 solution was higher (88% and 96%) compared to K2HPO4 solutions (70% and 29%). From the results obtained, the phosphorus can significantly be reduced using the seed sludge from the wastewater in short incubation time within one week. Thus, a sustainable approach in green technology can be further investigated and enhanced to overcome the environmental problems in reducing the phosphorus effluent discharge into the surface water system.
Physical and mechanical properties of clay sludge brick
Authors: Ibrahim A H , Bakar M Y A , Abidin C Z A , Ridwan F M , Jalil M F A
Published: February 2021

There are approximately 450 water treatment plants in Malaysia which produce potable water to consumers. During coagulation process, huge volume of sludge was produced particularly when turbid water was treated. The main objective of this work is to study the physical and mechanical properties of clay sludge brick. In this research, the sludge from the water treatment plant was used as clay replacement material in brick production. Several design mixtures of sludge and clay with different moisture content were used to prepare the brick. These bricks were fired at two different temperature (500°C and 900°C) before being tested for its physical and mechanical properties. Result shows that the presence of sludge in brick would increase the water absorption capacity of the brick. The water absorption was increased from 5.5% to 51% when the 60% (w/w) of sludge was incorporated into the mix. In term of burning temperature, higher temperature would improve the physical and mechanical properties of the brick. Based on the results, sludge from the water treatment plant shows huge potential as clay replacement in brick making process. Recycling the sludge from water treatment plants could solve the sludge disposal problem face by most of the plant operators.
Effectiveness of powdered activated carbon from fruit waste in removing heavy metals in groundwater
Authors: Baharudin Fauzi , Hamzah Nurhidayah , Wahab Mahyun Ab , Kang Choong Wee
Published: February 2021

This study was conducted to measure and compare the existing concentration of heavy metals in groundwater at riverbank. This study was also carried out to determine the effectiveness of activated durian rind which serves as powdered activated carbon (PAC) as an adsorption agent to remove heavy metals such as iron (Fe) and manganese (Mn) in groundwater. The initial concentration of Fe and Mn from all groundwater samples have exceeded the allowable standard. The process of removing iron and manganese was done by using 0.1g, 0.2g, 0.3g and 0.4g of activated durian rind. The results has shown a promising success with the percentage of removal with activated durian rind for iron ranging from 93.06% to 98.39%, while removal percentage for manganese ranging from 93.42% to 98.57%.
Effect of electrode materials on the degradation of palm oil mill effluent by electro-oxidation process
Authors: Abidin C Z A , Fahmi  , Ibrahim A H , Rahmat N R , Ahmad R , Hussein N F Mohamed , Choong P S , Singa P K
Published: February 2021

In the recent decades, Malaysia has been known as the one of the palm oil producers and exporters. The increasing of the production and demand of palm oil tends to increase the Palm Oil Mill Effluent (POME). Undeniably, the conventional biological treatment has been implemented to reduce the organic matters but insufficient to satisfy the discharge standard by the local authority. Consequently, the biological treated POME has to be treated further to meet the stringent discharge standard. Hence, an advanced oxidation processes (AOPs), electro-oxidation process (EOP) has been applied to treat further the biologically treated POME. There are two stages in this study, EOP carried on with catalyst and electrode (Al and Fe). Therefore, the performance of EOP is evaluated by investigating the removal efficiency on the organic parameters like COD, colour, suspended solid and NH3-N. The operational parameters are the pH adjustment (pH 3, 5, 7 and 9), contact time ranging from 0 to 60 min and the dosage of catalyst (H2O2 and TiO2). The highest degradation of the parameters was obtained under the most acidic solution pH 3, with addition of TiO2 by using Al electrode. The percentages of removal are 96.58 % of colour, 98.74 % of SS and 84.85 % of COD.
Experiment on fundamental behaviours of wavelength and height of vegetated alternate bar in river
Authors: Salleh Mohd Zulkhairi Mat , Ibrahim Zulkiflee , Saari Radzuan , Jumain Mazlin , Ismail Zulhilmi , Shariff Muhamad Effandi Mohd , Zulkifli Nurdalina Syuhada , Mazlan Che Ku Ahmad Lukman
Published: February 2021

The study on the alternate bar has been implemented by many researchers previously. However, the detailed analysis of the formation of the vegetated alternate bar is still not sufficient, especially on the bar wavelength, height, and width. Therefore, this present study provides an analysis of the experimental approach on the vegetated alternate bar formations. The focus was on the characteristics of wavelength, height, and width of the alternate bar. The objective of the study is to investigate the relationship of these parameters for three different conditions of alternate bar formations of non-vegetated, full and half patches of vegetation alternate bar. The flume of 10 m long and 1 m wide with erodible bed and fixed banks were used for the experiments with uniform bed sediment of size 0.8 mm. The wavelength and height of both full and half vegetated alternate bars increased compared to non-vegetated thus stabilized the formation of the alternate bar in the channels. The vegetation also reduced the value of the shield parameter to produce high deposition on the bar. The width of the bar increased at the head and body of the vegetated bar however it was decreased in the area of bar edge. Therefore, it could say that vegetation gives positive impacts on the alternate bar formation characteristics especially on its formation and stability in the rivers.
The effects of rainfall intensity to floor interception of Axonopus Compressus (Dwaft) under controlled condition
Authors: Azida A B Azinoor , Syahidah A M Nur , Lee W K
Published: February 2021

This study aims to quantify the amount of canopy storage capacity, to determine the canopy interception values and to investigate the effects of rainfall intensities to interception loss for Axonopus compressus (Dwaft) as floor vegetation under laboratory conditions. A rainfall simulator, Kohler GHE20 Hydrology apparatus, has been applied to produce an artificial rainfall with three different intensities. General water balance equation was applied where the changes in water storage between barren land and land with canopy cover was recorded to obtain the interception loss amount. Canopy storage capacity determined from this study was 1.35 to 0.48 mm for 90 to 180 mm/hr rainfall intensity, respectively. Meanwhile, the canopy interception obtained is 3 to 18% from the rainfall depth.
Field evaluation of using coconut husk and fibre to control slope erosion
Authors: Asha’ari Muhammad Afiq , Rahman Ena Kartina Abdul , Ratnayake Uditha , Tan Soon Jiann , Shams Shahriar
Published: February 2021

One of the most common temporary measures to control soil slope erosion is the placement of synthetic geotextile or biological cover over the sloping surface. However, synthetic geotextiles have some disadvantages. Firstly, they are much expensive compared to biological materials. Secondly, synthetic geotextiles made of polymeric materials are not biodegradable and are likely to cause soil pollution. The use of natural bio-resources, such as coconut husk and fibre, is less costly and they are readily available in tropical countries. It is environmentally friendly and also durable and will not decompose as fast as live mulches due to its high carbon to nitrogen ratio and lignin content. A field experiment is set up to test two designs of coconut mulches, coconut fibre net and coconut husk using onsite experimental erosion plots with a slope gradient of 27°. The results showed that the coconut husk placed in the correct orientation is effective in reducing soil loss (980 grams), produced two times less soil loss compared to the control plot of bare soil (2465 grams) and coconut fibre net (2410 grams). Both the mulch covers also enhanced soil and water holding capacity promoting vegetation growth.
Kinetic and isotherm studies of empty fruit bunch biochar on ammonium adsorption
Authors: Ahmad R , Sohaimi K S A , Mohamed A R , Zailani S N , Salleh N H M , Azizan N H
Published: February 2021

The presence of excessive ammonium in wastewater due to agriculture and other industrial activities affects the aquatic plants, animals and human health. Common wastewater practice offers high cost and maintenance as well as low performance. The adsorption technique offers an efficient, economically favourable and reliable physicochemical treatment method. Despite the efficiency, the studies on Empty Fruit Bunch (EFB) biochar as an adsorbent for ammonium removal is under discovered. The conducted study described the characterization of EFB biochar together with its kinetic and isotherm studies for ammonium removal. EFB underwent conventional pretreatment using fixed bed reactor at temperature of 350, 450,550 and 650 °C for 60 min of holding time prior for characterization and kinetic studies. For characterization studies, moisture, ash and pH anlysis were performed before proceed with adsorption and kinetic studies. It was found that the increment of temperature resulted in high content of ash and low content of moisture while optimum pH was in the range of pH 7. The optimum condition for ammonium adsorption was 2.5 ppm of EFB, 0.05g of ammonia dosage and time exposure of 200 minutes. The ammonium adsorption followed the pseudo-second-order kinetic model which suggests that the ammonium adsorption process is controlled by the chemical adsorption mechanism. The finding suggests the utilization of EFB biochar as a good alternative for ammonium removal through adsorption process while increasing the biomass value.
Effect of sonication on ZnO and ZnO-Fe catalyst for colour and COD removal from Methylene Blue solution
Authors: Ibrahim A H , Bakar M Y A , Abidin C Z A , Ridwan F M , Jalil M F A
Published: February 2021

Textile and cosmetics industries are among the industries which produce huge volume of dyes wastewater. Photocatalysis is of the methods that effectively treating dye wastewater. Semiconductor such as zinc oxide (ZnO) is one of the photocatalyst which is widely used in photocatalysis treatment method. In this research, removal of chemical oxygen demand (COD) and colour from Methylene Blue (MB) solution using ZnO were compared with ZnO doped with Fe. In addition, ultrasonic cavitation was also applied during the preparation of the catalyst. The catalysts were successfully synthesized through sol-gel method. By comparing all catalysts, sonocatalyst ZnO doped Fe produced the highest efficiency for colour removal. During the experiments, the colour removal from MB solution with 10 ppm and 30 ppm concentration were 99.65% and 51.3% respectively. This study concluded that the presence of ultrasonic cavitation during the catalyst preparation did change the physical and chemical characteristics of ZnO doped Fe. As a result, the catalyst worked better during the treatment system to remove colour from MB solution.
Oil palm in the face of climate change: A review of recommendations
Authors: A Ahmed , Y B I Mohd , A M Abdullah
Published: February 2021

Climate change imposes serious challenges in oil palm production and the current pace of adaptation and mitigation cannot continue to support oil palm production. We reviewed and analysed literature that reports sustainable recommendations, adaptation and mitigation measures to deal with impacts of climate change. Literature spanning the period 2000-2020 were systematically reviewed and several consistent recommendations emerged which require time frame and actionable plan for sustainability. The review categorized the identified recommendations into groups; fertilizer, policy, soil management, sustainability, water management, research and development, best development practices and agroecological practices. Sustainable implementation of adaptation requires collaboration from diverse disciplines to come together and work toward defined objective(s) through certain principles that guide adaptation; these principles must be consistent, operational and more specific, must be practical and achievable recommendation for inclusion into policies and must be embrace by all and sundry for sustainable development.
The estimation of greenhouse gas emission in leachate treatment plant and its carbon credit revenue
Authors: Izhar Tengku Nuraiti Tengku , Xuan Lim Pei
Published: February 2021

Landfilling disposal method has led to the more concern environmental issue around the world, which are greenhouse gas emissions. According to IPCC (2006), the waste sector is a major contributor to greenhouse gas (GHG) emissions, which accounts for about 5% of the global greenhouse budget. This 5% is methane (CH4) emissions from the anaerobic decomposition of solid waste and carbon dioxide (CO2) from the decomposition of wastewater. Methane is one of the most important greenhouse gas (GHG) due to it has about 21–23 times global warming potential than CO2. The CH4 and N2O emissions released in leachate treatment systems are the second-largest sources of greenhouse gases. The study is aimed to estimate methane emissions in leachate treatment plant in Landfill Rimba Mas Perlis, Malaysia, and its carbon credit revenue. The CH4 emission from the leachate treatment plant was estimated by using the United Nations Framework Convention on Climate Change (UNFCCC) methodology AM0013 and its economic benefit was determined based on the Clean Development Mechanism. From the study, the greenhouse gas emission in a leachate treatment plant has contributes to a reduction in carbon emissions by 233.21 tonnes/yr which could attract the carbon credit of RM 8,162.35 based on RM35/tonnes of CO2. The results indicate the anthropogenic emission in the leachate treatment plant can bring direct economic benefits to the local.
Utilization of Moringa oleifera seed waste as substrate in lipase production under different pretreatments
Authors: Irfansyah A R , Koentjoro M P , Isdiantoni  , Ekawati I , Prasetyo E N
Published: February 2021

Moringa industry in Sumenep Regency experienced growth in recent years along with the increase in export demand. Moringa seed waste, which is the coproduct of oil extraction contains a massive amount of lipid and biomass. As much as 30% of lipid residue from Moringa oleifera seeds waste are potentially usable as a substrate for lipase production. However, the phenolic compounds contained in the waste are difficult to degrade and have antimicrobial property which is needed to be removed. This study aims to determine the best pretreatment method in removing phenolic content in Moringa seed waste. The proposed pretreatment methods in this study including enzymatic pretreatment, Laccase Mediator System pretreatment, basic chemical pretreatment, acidic chemical pretreatment, and peroxide pretreatment. Lipase production carried out using Bacillus sp. SK II-5 isolates. Total protein content of lipases produced from various pretreatment then measured using the Bradford method. Lipase enzymatic activity determined qualitatively using the Quantofix formaldehyde test. Characterization of lipase based on isoelectric point. The result of this study is that laccase pretreatment is the best pretreatment method which capable of reducing total phenol concentration in Moringa seed waste by 70% to 3.87 mgGAE/g. The results were followed by a high total protein concentration of 0.43 mg/ml and lipase activity in the range of 100-200 ppm formaldehyde
Design and future application of mobile fish platform for local fishermen in the archipelago regions
Authors: Hetharia W R , Gaspersz F , de Fretes E R
Published: February 2021

The archipelago regions are spread out in some parts of Indonesia. These regions are related to maritime issues such as transportation, resources, infrastructures, and others. There are problems faced by local fishermen such as unavailable preservation facilities, sparse fish collectors and low income. A continuous study has been executing by the authors to define a proper fishing boat. A prototype of mobile fish platform was defined in the study to be operated in Moluccas waters. The fish platform was mobile catamaran type and provided with multi-fishing gears. The results of design and layout are presented in this paper. The study has been executed up to the platform construction phase and will complete in the future. In future scenario, the captured fishes will be transferred from the mobile fish platform to the existing fish cages to keep them alive. The whole scenario of future fishing operations with the mobile fish platform are also presented in this paper. The output of study is defined as prototype and will be tested at sea for technical and economic aspects before applying to users. The whole aim of future study is expected to increase fishermen catching products, to keep the fish alive for buyers and to increase economic aspects for the local fishermen.
Economic study on the construction of a 50 MW Ocean Thermal Energy Conversion (OTEC) facility in Banten Province, Indonesia
Authors: Rahmawati S , Muna A I , Wardhana W
Published: February 2021

Electricity demand is increasing every year along with economic growth and population in Indonesia. Meanwhile, non-renewable fossil fuels are still the main source of electricity generation in Indonesia. Therefore, the development of an affordable and environ-mentally friendly renewable energy-based power plant is very necessary. Ocean thermal energy sources available in abundance and has great potential in meeting national energy needs. In this study, a design concept of the 50 MW Ocean Thermal Energy Conversion (OTEC) facility was developed for Banten Province. Capital costs and expenditures for OTEC facilities were identified based on location requirements. The cost analysis is then combined with the OTEC facility investment scheme to obtain the Levelized Cost of Energy (LCOE).
Distribution of phytoplankton in Pangkep Waters, South Sulawesi, Indonesia
Authors: Thoha H , Bayu M D , Rachman A , Nasution A K , Siswantining T
Published: February 2021

The coastal water of Pangkajene Kepulauan, or Pangkep, in South Sulawesi has been influenced by high anthropogenic activities, where the inflow of nutrient from the land has caused several cases of harmful algal blooms and mass fish mortality. Thus, it was important to understand the community structure and distribution of phytoplankton, with particular interest on the bloom-forming and harmful genus, to better mitigate the effects of harmful algal blooms in the future. Sample collection for this study was conducted on May 2017 at 22 stations from three zones, the northern, middle, and southern coastal area of Pangkep. From this study, the phytoplankton density in Pangkep was found varied between 2.179 × 106 cells/m3 to 2.192 × 108 cells/m3, with the highest density of phytoplankton was observed in the northern and southern area of Pangkep. On the other hand, the middle area has lower phytoplankton density but has the highest diversity and evenness. Two stations, station 15 and 21, have a distinct phytoplankton community structure which might have caused by a combined effect of temperature and nutrient input from the land. Twenty-nine genera of phytoplankton were observed, with the diatoms Skeletonema as the most dominant genus which contributes to over 95% of total phytoplankton density. The occurrence of Ceratium, which once was found as a dominant genus in Pangkep coastal and estuaries, has caused a concern whether it might blooms and replacing the dominance of diatoms in these areas.
Alginate/PVA/chitosan injection composites as scaffold material for nucleus pulposus regeneration
Authors: Suryandaru H V , Aziz A I , Hanifah N , Rasyida A
Published: February 2021

Lower Back Pain (LBP) is common healthproblemin societywithprevalence80-85%. One of the causes of LBP is Herniated Nucleus Pulposus (HNP). This disease occurs in intervertebral discs (IVD), supporting the spine, found a gel fluid called Nucleus pulposus (NP) at the center surrounded by 15-20 concentric thin layers of the Annulus fibrosus (AF). This gel that will come out through AF and nerve pinched behind which makes sufferer feel pain and numb. Handling HNP with physical therapy only reduce the pain and not totally cured. While the surgery use discectomy method by eliminating the protruding parts NP or in whole, but has some drawbacks, such as: high cost, wide surgical incisions, probably occurrence of bleeding or other neurological disorders. Solving problem with find new methods that are faster, easier, and more affordable, we analyze using of alginate/PVA composite with chitosan suspense as a reinforcement as hydrogel injectable material to replace NP. Independent variable is chitosan percentage each sample, as much 5; 10; 15%. This study as a purpose to know mechanical properties, biocompatible, injectable performance, viscosity of alginate/PVA/chitosan, SEM-EDX test and FTIR test. The best result got is addition chitosan 15% appropriate as NP replacement.
Pre-evaluation of urease production by Bacillus sp. SK II-5 thermophilic bacteria using agricultural waste as a substrate
Authors: Destari D N , Koentjoro M P , Isdiantoni  , Ekawati I , Prasetyo E N
Published: February 2021

Agricultural waste contain nutritive minerals including nitrogen, phosphorus, and potassium which help plants grow faster and increase yields, but when released into the open environment can leads the aquatic environment to eutrophication. Agricultural waste, which is mostly contain urea, can be utilized for the growth media of microorganisms to produce urease. Urease is an enzyme that functions to hydrolyze urea to ammonia and carbonate. Naturally, some organisms can produce urease, one of which is the thermophilic bacteria of the genus Bacillus. The purpose of this research is determine the results of the viability test of thermophilic bacteria Bacillus sp. SK II-5 using small island agricultural waste as media. The viability test of Bacillussp. SK II-5 is carried out using the streak plate and turbidimetry methods. The results of this research were thermophilic bacteria Bacillus sp. SK II-5 can grow at 50°C and 60°C which have been tested for cell viability in agricultural waste extract agar media at 37°C.
Community empowerment of Sumberpelas, Plabuan Village-Jombang to create independent and sustainable Moringa oleifera village
Authors: Muslihatin W , Purwani K I , Ermavitalini D , Prasetyo E N , Nurhatika S , Nurhidayati T , Jadid N , Febrianti A , Yunas N S , Raikhani A , Sari L R
Published: February 2021

Plabuhan village, Jombang regency, East Java Province has a big potential in Moringa. Moringa is a plant that we encounter often around us that contains high nutrition. It is widely used especially for health. Potential that can be developed from Moringa’s leaf by S community is tea. As a product of the Plabuan village, the tea standards produced must be in accordance with the Indonesian National Standard (SNI) and the eligibility according to the Food and Drug Supervisory Agency (BPOM). To maximize this potential, assistance is needed to the Plabuan village community to process the Moringa’s leaf into high quality tea product. Through this assistance, it is expected that independent and sustainable Moringa oleifera villages will be realized. The results of the study showed that the community in Plabuan village was very active to contribute to utilisation and production of Moringa oleifera based products.
Analysis of angle comparison for the “Kawung” pattern module development based on additive manufacturing method using 3D filament from recycled plastic waste material
Authors: Prihandana D B , Kuswanto D
Published: February 2021

The process of additive manufacturing, particularly in 3D printing, is very closely related to CAD (Computer-Aided Design) files, 3D printers, and materials for creating object layers. Of course in the printing process, there are some limitations on the design and rules that must be considered. For example, material, design and printer settings to obtain maximum results. In this project an angle comparison analysis is performed on the Kawung module design to find out the most efficient and effective conditions in the printing process. From the strength test, the T3 Kawung module is found to be the most powerful with polypropylene material (recycled PP from Robries) with a yield strength of 20 MPa, a breakpoint of 13 N and maximum stress of 21.17 MPa.
Analysis of the effect of hull vane on ship resistance using CFD methods
Authors: Kiryanto  , Budiarto U , Firdhaus A
Published: February 2021

The development of technology in the ship industry is remarkable with many new innovations in the effort to improve ship performances. Ship resistance is one of the aspects that is very important to be comprehended the ship's characteristics. One of the innovations to reduce ship resistance is by adding hull vane to the ship hull. Hull vane is a fixed foil placed under the water line at the stern of the ship. This study is aimed to determine the effect of ship resistance after the addition of the hull vane and the location of the hull vane on the ship hull. This study utilizes a computer application program Computational Fluid Dynamic (CFD). The foil used is NACA 2415 type with s parameters angle of attack 5°, span foil 9.76 m, and chord hull vane length 1.15 m.. Investigations are further carried out on the variation of the vane hull at 2 different positions and implementation of single foil and double foil configurations. The results of this study indicate that the installation of a single foil hull vane on a ship can reduce vessel resistance and in contrast for the installation of double foil. In the case of single foil and its position at 50% of T = 2.9 m the resistance is found to be most optimally reduced when the vessel is operated at Froude number Fr = 0.342. The reduction in the total vessel resistance is 20.135% in comparison to the ship without a hull vane.
Technical and economic analysis on the using of Hibiscus Tiliaceus (Waru) and Boehmeria Nivea (Rami) fibres for fishing vessel mooring rope
Authors: Supomo H , Rahman A , Baihaqi I
Published: February 2021

Mooring rope of fishing boat made of synthetic fibre materials such as polypropylene or nylon can bring detrimental impacts to the environment as it is arduous to degrade. Natural fibre rope can potentially substitute the commonly-used undegradable mooring line to prevent further chain impacts. This paper aims to technically and economically analyse the tensile strength of mooring ropes made of two natural fibres, Hybiscus Tiliaceus (Waru) and Boehmeria Nivea (Rami), and to compare them with the former - conventional material manufactured rope. Tensile test, according to ASTM D3822, is performed to measure the tensile strength of the natural fibre ropes twisted into three different diameters (12 mm, 16 mm, 20 mm). Specimens are immersed in seawater for several weeks before testing. As a benchmark, this research examines unimmersed ones. The result shows that immersed Waru fibre ropes with three different diameters are 32.15 MPa, 27.10 MPa, 23.94 MPa, respectively; while for Rami fibre ropes are 37.58 MPa, 29.56 MPa, 24.31 MPa. Waru fibre rope is the most economical one if compared to Rami and synthetic fibre ropes. The manufacturing of mooring rope made of Waru fibres can save 19.4%, 11.5%, and 29.7% for each diameter variation, respectively.
Autopilot system design on monohull USV- LSS01 using PID- based sliding mode control method
Authors: Alim M F A , Kadir R E A , Gamayanti N , Santoso A , Bilfaqih Y , Sahal M
Published: February 2021

The Autopilot system for Unmanned Surface Vehicle (USV) can be applied by Sliding Mode Control which is a high frequency switching based control method and has discontinuous control action causing chattering on the system. Therefore, the Sliding Mode Control with natural control signal using a PID controller structure is applied to the USV. By using Sliding Mode Control, USV is expected to move accurately from the expected waypoint without any chattering on the system. The stability of the whole loop of system regulation is ensured using the Lyapunov stability function. The simulation results for autopilot system validate that the control parameters fit the time constant controller design specification and have zero steady-state errors. Further, autopilot system with waypoint navigation relatively generates small Mean Square Error (MSE) of waypoint.
Investigation of non-thermal atmospheric plasma for the degradation of avermectin solution
Authors: LV Yue , ZOU Liang , LI Huidong , CEHN Zilei , WANG Xiaolong , SUN Ying , FANG Liping , ZHAO Tong , ZHANG Yuantao
Published: February 2021

Increasing concern with regard to food safety in the presence of pesticide residues (PRs) on the surface of agricultural products has resulted in the rapid development of practical degrading technologies for corresponding PRs. In this paper, an unconventional method of degrading pesticides, non-thermal atmospheric plasma (NTAP), was proposed to degrade the avermectin (AVM) in aqueous solution. Optical emission spectroscopy shows that NTAP, consisting of filamentary streamers, contains a variety of reactive oxygen species (ROS) that may interact with AVM. The high-performance liquid chromatography (HPLC)-MS/MS results indicate that the efficiency of AVM degradation seriously depends on multiple operation parameters of the NTAP, including the applied voltage, treatment time and gas flow rate. The maximum degradation rate of AVM was observed to be 97.47% after 240 s exposure under NTAP with an applied voltage of 18 kV and gas flow rate of 1 l min−1. Molecular dynamics simulation based on a reactive force field for the interaction between O (ground state atomic oxygen) and AVM was performed to analyze the underpinning mechanisms. The simulation result shows the possible pathways of the NTAP-generated O degrading AVM by destroying the glycosyl group or fracturing the ester group.
Lattice parameter of Am, Np bearing MOX fuel: an empirical potential study
Authors: Caglak Emre , Labeau Pierre-Etienne
Published: February 2021

An empirical potential study was performed for the americium (Am), neptunium (Np) containing uranium (U) and Plutonium (Pu) mixed oxides (MOX). The configurational space of a complex U1-y-y′-y″PuyAmy′Npy″O2 system was predicted by the rigid lattice Monte Carlo method. Based on the computing time and efficiency performance, the method was found to rapidly converge towards the optimal configuration. From that configuration, the relaxed lattice parameter of Am, Np bearing MOX fuel was investigated and compared with available literature data. As a result, a linear behaviour of the lattice parameter as a function of Am, Np content was observed.
Recent progress in self-healing conductive materials and flexible sensors with desired functional repairability
Authors: Zhou Cun , Liu Jize , Lv Zhen , Luo Yongyue , Zhang Xinxing
Published: February 2021

Flexible sensors with skin-like self-healing and sensing properties are now drawing great attention for their prospective application in many promising fields, including electronic skins, wearable electronics and soft robots. However, the unavoidable irregularity external stimuli and repetitive motions usually resulting in function loss. So, the self-healing abilities on both mechanical and electrical characters are highly attractive. Till now, numerous studies have been given to realize the self-healing of mechanical properties, while the repair of electrical properties still remains a great concern. Herein, the current main methods to prepare self-healing flexible sensors are summarized and discussed, consisting of self-healing materials with conductive layers, self-healing materials with embedded conductive network and self-healing ionic conducting hydrogels. Finally, a summary and perspective on future research directions and the potential of each strategy are given.
Learning to unknot
Authors: Gukov Sergei , Halverson James , Ruehle Fabian , Sułkowski Piotr
Published: February 2021

We introduce natural language processing into the study of knot theory, as made natural by the braid word representation of knots. We study the UNKNOT problem of determining whether or not a given knot is the unknot. After describing an algorithm to randomly generate N-crossing braids and their knot closures and discussing the induced prior on the distribution of knots, we apply binary classification to the UNKNOT decision problem. We find that the Reformer and shared-QK Transformer network architectures outperform fully-connected networks, though all perform at

≳

95% accuracy. Perhaps surprisingly, we find that accuracy increases with the length of the braid word, and that the networks learn a direct correlation between the confidence of their predictions and the degree of the Jones polynomial. Finally, we utilize reinforcement learning (RL) to find sequences of Markov moves and braid relations that simplify knots and can identify unknots by explicitly giving the sequence of unknotting actions. Trust region policy optimization (TRPO) performs consistently well, reducing

≳

80% of the unknots with up to 96 crossings we tested to the empty braid word, and thoroughly outperformed other RL algorithms and random walkers. Studying these actions, we find that braid relations are more useful in simplifying to the unknot than one of the Markov moves.
Is credibility a guide to possibility? A challenge for toy models in science
Authors: Sjölin Wirling Ylwa
Published: February 2021

Several philosophers of science claim that scientific toy models afford knowledge of possibility, but answers to the question of why toy models can be expected to competently play this role are scarce. The main line of reply is that toy models support possibility claims insofar as they are credible. I raise a challenge for this credibility-thesis, drawing on a familiar problem for imagination-based modal epistemologies, and argue that it remains unanswered in the current literature. The credibility-thesis has a long way to go if it is to account for the epistemic merits of toy models.