bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrated Ni-CNT as a bifunctional catalyst for Li-O2 batteries
Authors: Cao R F , Liu J W , Liu W Q
Published: June 2022

Using thermal evaporation technology, Ni-CNT are grown in-situ on nickel plates as the cathode of Li-O2 batteries. This integrated electrode structure eliminates the negative impact of binders on the electrochemical performance and greatly reduces the process for preparing the lithium oxygen battery cathode. Ni-CNT exhibit excellent catalytic activity, and provide an ultrahigh discharge specific capacity of approximately 4.3 mAh cm−2 at 0.1 mA cm−2, the discharge voltage plateau is stable above 2.79 V. In addition, it exhibits a low polarization potential of only 3.34 V during charging, which is much lower than that of the commercial Ru-CNT cathode, and the cycle life of 151 cycles is much higher than that of the commercial Ru-CNT cathode even under a high specific capacity (0.3 mAh cm−2). This self-supporting structure provides abundant space for oxygen transmission and discharge products, and shows great application prospects.
Optimization of micro methanol steam reforming reactor
Authors: Zhu Ruihan , Zuo Min , He Zhenzong
Published: June 2022

In this paper, a micro reactor integrating hot air heating and methanol steam reforming hydrogen production (MSR) reaction is designed. Firstly, the mechanism of the reactor is studied. The Arrhenius chemical reaction rate evaluation model and simple-c algorithm are applied, the hot air is used to simulate the heat supply of engine exhaust, and the three-dimensional design simulation of the new structure reactor is carried out. The effects of the number of hot air inlet holes, parallel flow, counter flow and inlet schemes on the reactor are investigated. It is found that the conversion of methanol can reach 71.08% with the better inlet scheme of parallel flow in the two-hole condition. Then, taking the comparison of methanol conversion as the index, the correspondence between hot air and electric heating in a certain range is explored. The results of the study have implications for conducting research on the comprehensive utilization of waste heat from engines and the heat reforming for hydrogen production.
A cross-attention based image fusion Network for prediction of mild cognitive impairment
Authors: Li Jiyun , Bu Chao , Qian Chen
Published: June 2022

Mild cognitive impairment (MCI) is the intermediate stage in the progression of Alzheimer’s disease, where patients exhibit cognitive decline, decreasing ability to perform complex daily tasks and other symptoms that can be mistaken for normal aging, thus missing the optimal time for treatment and leading to further deterioration of the patient’s condition. Structural magnetic resonance imaging (sMRI) and positron emission tomography (PET) are commonly used to examine patients in clinical practice. Currently, the fusion of sMRI and PET based on deep learning are simply extracting features individually and then fusing the extracted features, ignoring the correlation between features of two different modalities. Therefore, this paper proposes an image fusion method based on cross-attention mechanism, which makes it possible to focus not only on the features of its own view but also on the features of the other view during feature extraction to achieve dual-attempt cross-learning. The experimental results from the Alzheimer’s Disease Neuroimaging Initiative dataset show that the images fused based on the method proposed in this paper outperform the original method in three evaluation indexes: peak signal-to-noise ratio, structural similarity and classification accuracy.
Vehicle detection in foggy weather based on an enhanced YOLO method
Authors: Li Wei
Published: June 2022

Vehicle detection is the key to driverless technology. For safety, driverless technology requires extremely high accuracy and real-time for vehicle detection in different situations. In this paper, we study an enhanced YOLO -based algorithm for vehicle detection in foggy weather conditions. We add a dehazing module in the YOLO model for more information restoration, which is built by the multi-scale retinex with color restoration (MSRCR). And the enhanced model is trained with the augmentation data processed MSRCR for more stable performance. We evaluate our method in the public dataset, the results show the enhanced YOLO model has better performance than conventional YOLO in vehicle detection in foggy weather.
Detection algorithm of aerial vehicle target based on improved YOLOv3
Authors: Xu Minjie , Wang Xinhua , Zhang Shuai , Wan Ru , Zhao Fukang
Published: June 2022

In order to solve the problems of large number, small size and low detection accuracy of vehicle targets in aerial photography, a target detection algorithm based on improved YOLOv3 is proposed in this paper. Firstly, aiming at the problem of small target information loss of road vehicles, a new detection size is added.Secondly, in order to better detect small targets, a 104x104 scale detection layer is added on the basis of the three detection layers of the traditional yolov3 network structure.The k-means + + algorithm is used to cluster the data set, and a new ground target detection candidate frame is obtained. The loss function is improved by using Focal loss function in the classification loss function and using DIoUloss function based on IoUloss improvement in the regression loss function.The improved YOLOv3 algorithm can identify the road vehicle target more accurately without the decline of speed, and reduce the miss rate. The improved algorithm is tested on Visdrone dataset, and the experimental data show that the average accuracy of the improved algorithm is 94.04%, and the average detection accuracy (mAP) is improved by 2.94%.The detection accuracy of the proposed improved YOLOv3 algorithm is better than that of YOLOv3.
UAV Aerial Photography Target Detection Algorithm Based On Improved YOLOv5
Authors: XIE Liangchen , XUE Yali , YE Jinze
Published: June 2022

Aiming at the characteristics of complex background and less target pixels in UAV aerial images, a UAV aerial target detection algorithm based on improved yolov5 is proposed in this paper. First, the low-level feature map with richer small target information is introduced into the feature fusion network, so a new prediction head is added. Then, the structure of the feature fusion network is improved to realize cross layer connection and assign different weights to each feature map. Finally, the loss function is optimized to further improve the detection accuracy of the model. The model is trained with VisDrone data set. The results show that the average accuracy of the improved algorithm is improved by 4.6 percentage points compared with yolov5x, and it has better detection performance for scenes with complex background and dense small targets.
Influence of inclusion defects on bending properties and failure modes of composites
Authors: Luo Ning , Xiao Shi , Wang Zhanbin , Liu Bintao
Published: June 2022

A comparison test was carried out between the simulated inclusion sample and the normal sample, and the test section was subjected to pure bending loading by three-point bending loading method. The influence of different inclusion positions on the bending mechanical properties of the composite was analyzed. The fracture surface of the specimen was observed macroscopically and by scanning electron microscopy, and the load transfer and failure mechanism of the specimen were studied from macroscopically and microscopically. The results show that the distance of the simulated inclusions and the position of loading surface have great influence on the bending properties of the composites. When the simulated inclusion is far from the loading surface, delamination cracking does not occur in the simulated inclusion area, and the bending property of the simulated inclusion sample is improved rather than decreased, that is, the presence of inclusion does not necessarily reduce the bending property of the composite.
Effect of Furnace Cold Annealing on Microstructure and Tensile Properties of TC18 Titanium Alloy
Authors: Zhang Yafeng , Zhang Mingyu , Pan Yizhen , Yue Xu , Tong Xiaole , Yang Mengdi
Published: June 2022

TC18 alloy bars were annealed at different temperatures, and then the tensile properties were tested. The effects of different furnace cooling temperatures on the microstructure and tensile properties of the alloy were analyzed by optical microscope and scanning electron microscope. The results show that after furnace cooling at different temperatures, the size, distribution and appearance of α phase in the microstructure are changed to varying degrees. With the increase of temperature, the α phase in the microstructure disappears, the elongated α phase becomes thinner, the grain boundary α phase appears, and the obvious β grain appears. The strength of the alloy increases with the increase of temperature, and the plasticity shows the opposite trend. The maximum tensile strength is 1131 MPa, the maximum yield strength is 992 MPa, the maximum elongation is 14 %, and the maximum section shrinkage is 34 %. When the temperature is in the two-phase region, the morphology is mainly dimples, and the dimple morphology is large and deep. When the heating temperature is in the single-phase region, the fracture morphology is mainly crystalline, with tearing edges and a small amount of shallow dimples distributed on the surface.
Analysis of current distribution of electrode change operation in aluminium electrolysis based on equivalent circuit computer numerical
Authors: Lv Jian , Wang Yifan
Published: June 2022

The development of industrial aluminium electrolytic cells towards higher series currents and a larger number of anodes, coupled with the fact that China has made more restrictions on high energy-consuming industries, has placed higher demands on the management of the aluminium electrolytic industry. In this study, a digital twin model of the electrolytic cell based on the idea of equivalent circuits was constructed using Matlab/Simulink software to simulate the electrode change operation and to study its effect on the change of current field. It is shown that the electrolysis temperature and the change of ACD caused by horizontal current have an effect on the current distribution.
Analysis of Thermal Fracture for Nonhomogeneous Materials Plate with Multiple Cracks
Authors: Sun Yiding , Zhang Zehui , Ye Ti , Zhang Yanyan
Published: June 2022

In this paper, the transient interaction integral method (IEIM) is established to obtain the transient thermal stress intensity factors (TSIFs) in order to study the fracture problems of nonhomogeneous materials under thermal shock loading. The transient temperature field is evaluated by using the finite difference method and the finite element method. The TSIFs of nonhomogeneous materials with multiple cracks are analysed, then the mixed-mode TSIFs of nonhomogeneous materials with different positions are discussed. The results of this study have shown that the current approach is applicable to obtain fracture parameters of nonhomogeneous materials with multiple cracks efficiently, which can be used as a significant reference for the engineering application of nonhomogeneous materials.
Experimental study on bearing capacity of a Tensairity arch
Authors: Lv Lin , Fan Zijian , Sun Haitao
Published: June 2022

Based on the advantages of tension-string structures and inflatable membrane structures, this paper proposes a Tensairity arch and designs and builds a model for the structure. The mechanical response of the structure under a concentrated load is studied by carrying out static tests. From three aspects of the midspan deflection deformation, the strain of upper chord member and the tension of steel cable, this paper studies the influence of the internal inflation pressure, the tension of the lower chord steel cable, and the combinations of the steel cable on the bearing capacity of the structure. The results show that increasing the inflated air pressure to a certain extent can significantly improve structural stiffness, but compared with traditional spindle-shaped Tensairity, the prestress applied during the inflation process is not conducive to enhancing the structural load-bearing capacity. Changing the stress distribution of the upper chord member by tensioning the lower chord cable is beneficial to achieve a better material performance and weaken the adverse effects caused by the inflation of the airbag. The supplementary tension of the horizontal steel cable can improve the ultimate bearing capacity of the structure, thus contributing to the safety of the structure.
Time-space Domain Elimination Method of High-Temperature Thermal Disturbance Test Error
Authors: Lou Qun , Lv Junhao , Wen Lihua , Xiao Jinyou
Published: June 2022

The digital image correlation (DIC) test method has been widely used in structural deformation measurement due to its non-contact and full-field. However, eliminating the effects of temperature-induced thermal disturbance is a primary challenge in high-temperature DIC measurements. In this paper, the measurement error is regarded as the superposition of zero-mean random error and non-zero mean system error, a time-space domain disturbance error elimination method is proposed to eliminate the adverse effects of thermal disturbance. Firstly, the noise images are averaged in the time domain to reduce the DIC matching error caused by zero-mean random noise. Then the noise displacement field is locally weighted quadratically smoothed in the space domain to eliminate the non-zero mean system error. The experimental results show that the proposed method can improve the high-temperature deformation measurement accuracy compared with the single-domain processing method. This paper will provide a new method for improving the measurement accuracy in DIC full-field deformation measurement under a high-temperature environment.
Displacement Analysis on Plane Stress Problems
Authors: Zhu Xuli , Ma Shanshan , Huang Haidong , Wang Xiaodong , Teng Guirong
Published: June 2022

The vertical z direction displacement component and its effect are not considered in the displacement analysis of the plane stress problems currently, and it may cause misunderstanding of the problems. The plane stress problems are three-dimensional problems actually because the strains are three-dimensional. The relationships among stress, strain and displacement of plane stress problems were analyzed in three-dimensional space based on the basic theory of elasticity in this paper. According to the characteristic constraints of the plane stress problems, the displacement expressions in three directions were derived. The displacement in the plane consists of the integral of the plane strain in the x-y plane and the independent function of the z-direction. Under the condition that the plane stress problem is strictly satisfied, the first stress invariant should be linearly distributed in the plane, and the displacement in the z direction is the product of the x, y related linear function and z.
Experimental investigation on ballistics resistance of UHMWPE fiber laminates
Authors: Zhou Nan , Zhu Jingwei , Jiang Jing , Zhou Guixue
Published: June 2022

To study the application of ultra-high molecular weight polyethylene fiber (UHMWPE) laminates in light protection field, the ballistic test was used to study the ballistic resistance of UHMWPE fiber materials. In the experiment, 9mm standard bullets were launched by a revolver pistol and 92 type pistol to penetrate the fiber laminates respectively, and the initial velocity of the bullet was recorded by the infrared tachometer. The influence of the areal density, the number of layers, the incident angle and the initial velocity on the protective properties of the fiber laminates were discussed, meanwhile, the microscopic characteristics of the failure mode of the fiber laminates were studied by stereomicroscope. The results show that the areal density and the layer number have obvious influence on the ballistic resistance of the fiber laminates, and the influence of the two materials should be taken into account. In the non-penetrating condition, the total deformation of the fiber laminates is large and the failure of the fiber bundle is the main failure mode. And when penetrated completely, the tensile fracture of fiber laminate material is the main failure mechanism. The study of this paper provides experimental reference for the structural design of UHMWPE fiber laminates.
The effect of solvents on the morphology of NTO crystal by molecular dynamics
Authors: GE Ming , CHEN Kun , LI Lijie , HUANG Lun , NING Liyuan , LIU Qiaoe
Published: June 2022

In this paper, a molecular model for adsorption of NTO surface-solvent was constructed, and the effects of different solvents on the morphology of NTO crystal were simulated by molecular dynamics. The selected solvents included ethanol, water, acetone, N-methylpyrrolidone (NMP), ethyl acetate and N,N-dimethylformamide. Pure solvents and two co-solvents including NMP/water and ethanol/water were studied to provide theoretical guidance for the selection of solvent systems for NTO recrystallization. In pure solvents, the results show that the crystal morphology of NTO can be effected by all solvent and in NMP solvent is the best. In co-solvents, when the mass ratio of ethanol to water is 9:1, the best morphology of NTO crystals is found . In ethanol/water system, the morphology of NTO crystals changes from near-cube to cuboid with the decrease of ethanol mass fraction, and the aspect ratios of NTO crystals increase. In NMP/water system, the decrease of the mass fraction of NMP makes the crystal morphology deteriorate. This is manifested as the crystal develops towards a narrow needle shape, and the value of the aspect ratio increases.
Tackling climate risk to sustainably intensify smallholder maize farming systems in southern Africa
Authors: Nelson William C D , Hoffmann Munir P , May Carlotta , Mashao Frederick , Ayisi Kingsley , Odhiambo Jude , Bringhenti Thomas , Feil Jan Henning , Yazdan Bakhsh Sara , Abdulai Issaka , Rötter Reimund P
Published: June 2022

Sustainable intensification (SI) of low input farming systems is promoted as a strategy to improve smallholder farmer food security in southern Africa. Using the Limpopo province South Africa as a case study (four villages across a climate gradient), we combined survey data (140 households) and quantitative agronomic observations to understand climate-induced limitations for SI of maize-based smallholder systems. Insights were used to benchmark the agroecosystem model Agricultural Production System sIMulator, which was setup to ex ante evaluate technology packages (TPs) over 21-seasons (1998–2019): TP0 status quo (no input, broadcast sowing), TP1 fertiliser (micro dosing), TP2 planting density (recommended), TP3 weeding (all removed), TP4 irrigation, TP5 planting date (early, recommended), and TP6 all combined (TPs 1–5). An additional TP7 (forecasting) investigated varying planting density and fertiliser in line with weather forecasts. Input intensity levels were low and villages expressed similar challenges to climate risk adaptation, with strategies mostly limited to adjusted planting dates and densities, with less than 2% of farmers having access to water for irrigation. Simulations showed that combining all management interventions would be expected to lead to the highest mean maize grain yields (3200 kg ha−1 across villages) and the lowest harvest failure risk compared to individual interventions. Likewise, simulations suggested that irrigation alone would not result in yield gains and simple agronomic adjustments in line with weather forecasts indicated that farmers could expect to turn rainfall variability into an opportunity well worth taking advantage of. Our study emphasises the need for a cropping systems approach that addresses multiple crop stresses simultaneously.
Detection of differentiated thyroid carcinoma in exhaled breath with an electronic nose
Authors: Scheepers Max H M C , Al-Difaie Zaid J J , Wintjens Anne G W E , Engelen Sanne M E , Havekes Bas , Lubbers Tim , Coolsen Marielle M E , van der Palen Job , van Ginhoven Tessa M , Vriens Menno , Bouvy Nicole D
Published: June 2022

This proof-of-principle study investigates the diagnostic performance of the Aeonose in differentiating malignant from benign thyroid diseases based on volatile organic compound analysis in exhaled breath. All patients with a suspicious thyroid nodule planned for surgery, exhaled in the Aeonose. Definitive diagnosis was provided by histopathological determination after surgical resection. Breath samples were analyzed utilizing artificial neural networking. About 133 participants were included, 48 of whom were diagnosed with well-differentiated thyroid cancer. A sensitivity of 0.73 and a negative predictive value (NPV) of 0.82 were found. The sensitivity and NPV improved to 0.94 and 0.95 respectively after adding clinical variables via multivariate logistic regression analysis. This study demonstrates the feasibility of the Aeonose to discriminate between malignant and benign thyroid disease. With a high NPV, low cost, and non-invasive nature, the Aeonose may be a promising diagnostic tool in the detection of thyroid cancer.
Tourism Mitigation Among Crisis, A Case Study from Borobudur in Environment, Economic and Social Perspectives
Authors: Kresnanto N C , Putri W H
Published: June 2022

The tourism industry is a significant GDP contributor to almost all countries globally (10.4% on average in 2019). For every four new jobs that appear, it is recorded that one job is from the tourism sector. But on the other hand, this industry is also an industry vulnerable to the effects of crises such as economics, politics, disasters, and pandemics. Next, to determine how much influence the economy, politics, disasters, and pandemics have on tourism, it is necessary to conduct a comprehensive study of these effects by taking lessons from various events. Furthermore, the study will also discuss Borobudur in-depth and see the possible tourism growth trend after the crisis. Borobudur tourism has experienced good growth in a polynomial function, has slumped due to the Covid-19 pandemic by more than -75%. Lesson learned from the previous crisis, conditions will return to normal 3-4 years from the first impact of the pandemic. If growth is calculated from the lowest position during the pandemic, it is estimated that Borobudur tourism conditions will return to conditions in 2017 (peak conditions) in 2029.
Economic Analysis of Urban Land Use in Yogyakarta City
Authors: Raharti R , Burhanudin  , Kartinah  , Jebarus B
Published: June 2022

This study aims to analyze the use of urban land in the city of Yogyakarta economically. The analytical method used in this research is multiple linear regression with Ordinary Least Square (OLS). This library uses secondary data, namely economic growth, population density, migration, and land use. The formulation of the research problem is how the impact of economic growth, population density, and migration on urban land use in the city of Yogyakarta. The results showed that economic growth, population density, and migration positively and significantly affected urban land use in Yogyakarta. The Yogyakarta City Government needs to increase economic growth by encouraging investment in sectors to increase regional income. Investment incentives can cover various aspects affecting the increase in GRDP. In addition, the city of Yogyakarta should encourage increased income growth to optimize the region’s potential to support economic growth.
Public Trust Doctrine in Indonesia: Expectation and Prospect
Authors: Hapsari M A , Suswoto  , Ariyani N
Published: June 2022

Public Trust Doctrine (PTD) is a principle that states the government holds the trust of natural resources for public interest or public use above all interest, even if it is already a private-owned property. A similar clause can be found in Article 33 (3) of Indonesia’s 1945 Constitution that states all of the vital natural resources are under the control of the State and used for the maximum benefit and prosperity of the people. On the contrary to its Constitution, Indonesia’s government enacted many unfortunate regulations that promote unsustainable exploitation of natural resources and tossing aside public interest and welfare. The research described how other countries perceive PTD and its practices and then follows the possibilities and prospects of conducting PTD in Indonesia’s law perspective. The research is a qualitative research conducted in doctrinal legal method with a comparative and analytical approach. From the arguments and analysis conducted, PTD can be adopted and integrated in Indonesia environmental scenes with amendment and conformation to current applied law.
Reproduction performance of corydoras fish Corydoras paleatus spawned with different male to female ratio
Authors: Maulana F , Carman O , Putra A K
Published: June 2022

The sex ratio in spawning can affect the efficiency and success of hatchery activities because sex ratio in spawning affects the number of eggs, the degree of fertilization, and the degree of hatching of eggs. Until now, there is limited research conducted in Corydoras paleatus fish spawning thus this study aims to determine differences in the reproductive performance of C. paleatus with different male sex ratios. This study uses three treatments, which are the ratio of fish male and female (1:1), (2:1), and (3:1). Each treatment uses one female fish. The vessel used in fish spawning is an aquarium with a size of 50 × 25 × 30 cm3. Spawning lasts for seven days and eggs are collected every day at 08.00. The number of eggs and larvae produced was not significantly different between treatments. Larvae produced by C. paleatus were 2,154 fish or 538 fish per female per week. The ratio (1:1) was considered an appropriate ratio in spawning C. paleatus fish because it has a high efficiency value.
Protogynous sex change in ricefield eel Monopterus albus (Zuiew, 1793) by hormonal induction using javanese chili extract (Piper retrofractum Vahl)
Authors: Soelistyowati D T , Arfah H , Maulana F
Published: June 2022

The ricefield eel Monopterus albus (Zuiew, 1793) is a protogynous hermaphrodite that undergoes sex change from female at the beginning of its life cycle to becoming male after going through the intersex phase. This study aims to evaluate the sex status of ricefield eels measuring 18–55 cm and the development of protogynous sex change by hormonal induction using Javanese chili extract (Piper retrofractum Vahl) through injection. One hundred and twenty eels averaged 24.86 ± 0.76 cm of length and 10.65 ± 0.83 g of weight was used in this research. A completely randomized experimental design consisted of four treatments (different doses of Javanese chili extract) and three replications were applied in this research. The dose of Javanese chili extract given was 187.5 g.kg-1 fish (P1) and 375 g.kg-1 fish (P2) compared to the control with injection using NaCl 3 mL.kg-1 fish (P0) and without injection (K). Injections through intramuscular were given 5 times with an interval of 7 days and observations of sex status were carried out every 14 days based on the development of the gonads. In the normal conditions, the sex status of ricefield eels measuring 20-33 cm in length indicates females, while intersex has a length ranging from 33–43 cm, and males with a length range of 43–55 cm. Hormone induction by injection of Javanese chili extract at a dose of ECJ 375 g.kg-1 fish produced a sex change percentage of eels with 75% male sex status and 25% intersex with an average length of 24.88 ± 0.35 cm and a weight of 10.22 ± 0.14 g.
Catching trial around portable Fish Aggregating Devices (FADs) at Belitung Waters
Authors: Yusfiandayani Roza , Mulyono  , Nugroho Sahrin
Published: June 2022

Belitung Regency is an administrative area in the Bangka Belitung Islands Province. Handline is one of the most popular fishing gear in Belitung Island. However, the production value of handline fishing gear has decreased recently. This decrease was caused by the lack of fishing technology in handline fishing which potentially threatened the sustainability of small-scale fishing industry in the region. The use of portable Fish Aggregating Devices (FADs) technology was expected to increase the productivity of handline fishing gear. This study aims to compare the composition of handline catch, productivity, and fishers total income using portable FADs and without FADs. Sixteen experimental fishing trips were conducted to collect data. The results showed that the dominant catch of handline using portable FADs was threadfin breams (Nemipterus hexodon) (50.7%), greater lizardfish (Saurida tumbil) (27.4%), yellow stripe threadfin bream (Pentapodus aureofasciatus) (10.7%), grouper (Epinephelus bleeker) (4.6%), monocle bream (Scolopsis sp.) (4.2%), yellow jack (Caranx bartholomei) (2.1%), and mackerel (Acanthocybium solandri) (0.2%). The number of catches using portable FADs was 521 of fish (37%), while the one without FADs was 888 of fish (63%). However, based on its weight, the operation using portable FADs resulted in 84.4 kg (58%) and those without FADs was 61.6 kg (41%). The productivity of handline fishing with portable FADs was higher, 1.32 kg / trip, compared to its counterpart which was 0.91 kg / trip. Based on the Kruskal-Wallis test, it showed that the use of portable FADs has a significant effect on handline fishing. Additionally, the total income of fishermen with portable FADs was higher than those without portable FADs.
Spatio-temporal of mangrove vegetation based on the analysis of multi-temporal sentinel-2 satellite imageries at Jepara Regency, Indonesia
Authors: Hayati Arif Noor , Afiati Norma , Supriharyono  , Helmi Muhammad
Published: June 2022

Mangrove areas in the northern coast of Jepara Regency have been threatened by coastal erosion and changes in land use since 1980. These areas represent coastal ecosystems with significant ecological, biological, and economic importance. The status of these ecosystems needs to be monitored; the latest condition is important to local authorities. Rate of change in mangrove conditions can be used to forecast the future condition of these coastal areas. This study aims to determine the temporal changes in the area and density of mangrove vegetation in Jepara Regency in 2017 and 2020. This study applied analysis of Sentinel 2-A multitemporal satellite imagery and classification using random forest on the Google Earth Engine platform. It was found that the mangrove area shrank from 103 ha in 2017 to 95 ha in 2020. The vegetations showed that changes in mangrove area in Jepara Regency have decreased in the rare and dense mangrove density types. The density of rare and dense mangroves experienced a decrease in area of 6 and 5 hectares, respectively. No mangroves with dense cover were found in 2020. Meanwhile, mangroves with moderate cover experienced an increase in area of 3 hectares in 2020 compared to last year 2017.
Low genetic diversity and a mixing population of the reef Manta ray (Mobula alfredi, Krefft 1868) between three populations across Indonesian seas revealed by Mitochondrial DNA
Authors: Phardana T , Subhan B , Naulita Y , Sani L M I , Madduppa H
Published: June 2022

Mobula alfredi is a critically endangered species of the Mobulidae family that can be found in the subtropics, including Indonesia. However, population connectedness, which is critical for managing and conserving populations, was previously unknown. Based on 614-bp of cytochrome oxidase 1 (COI) mtDNA, this study looked into the genetic structure and genetic diversity of M. alfredi between three major populations in Indonesia (Raja Ampat, Komodo Island, and Nusa Penida). Between April and December 2016, 72 tissue samples were collected using the biopsy during expedition. Komodo Island has the largest haplotype diversity and nucleotide diversity, while Raja Ampat and Nusa Penida had the lowest. Low and non-significant genetic differences were discovered between groups. The genetic variation values from the entire population revealed a greater variety within the population. Individuals of M. alfredi from three populations were mixed over Indonesian seas, as shown by the phylogenetic reconstruction and haplotype network, which was divided into two groups. M. alfredi is vulnerable to environmental change because of its low genetic diversity.
Forecasting the stranded area of marine debris in Indonesian coasts using mobidrift model and floating drifter
Authors: Gautama B G , Rizal A , Rahmania R , Farhan A R , Berlianty D , Priyono B , Siong K , Harjono M R , Voisin J B , Maes C , Dobler D , Dufau C , Lucas M , Fauny O
Published: June 2022

The problem of marine debris became a concern of world scientists that placed Indonesia as the second contributor of the world. Plastic litter that leaked from the land and came through the river is a major source of Indonesia marine debris. This marine debris is a serious threat for ocean and coastal ecosystems. The Ministry of Marine Affairs and Fisheries of Indonesia supports the Presidential Regulation to reduce the plastic litter to 70% by 2025 by developing numerical modeling of marine plastic litter trajectory. Using a user-friendly web portal interface, we can simulate the trajectory of marine plastic litter from different points of source at different seasons. Wind, current, and tide data were used to force the particle on the simulation. The result of the model was compared with the record of the real time movement of twenty drifters that were released from three rivers mouth. The development of this trajectory model will become a useful tool to provide the information of the movement of marine debris in Indonesian sea waters and beyond. Knowing the path and stranded location in each season will improve our policy of planning and mitigate the impact of marine debris.
Development and growth of massive coral Lobophyllia hemprichii transplanted on Pramuka Island, Thousand Islands, Jakarta
Authors: Arafat Dondy , Soedharma Dedi , Subhan Beginer , Madduppa Hawis , Ervina Ayu , Santoso Prakas , Margono Widyarto , Hidayat Silki Anisa , Anggraeny Bunga
Published: June 2022

The condition of coral reefs in Indonesia is declining, one of the efforts to restore the condition is to carry out coral transplants. The method used in this research is fragmentation transplantation. This study was conducted to determine the effect of fragmentation (cutting) on coral species Lobophyllia hemprichii from F1 parent transplants carried out on Pramuka Island, Seribu Islands Jakarta. There were two types of coral cutting treatment, namely L1 (wound 1) and L2 (wound 2), with 14 replications. This study showed that there was no effect on the number of cuttings on the survival (SR) and growth of the sub-massive coral Lobophyllia hemprichii (P>0.05). All coral fragments were alive until the end of the observation (SR=100%) and there was an increase in fragment length every month in 2 treatments. The increase in length over 6 months in corals with 1 wound was 10.17 mm (from 67.48 mm to 79.65 mm) and in corals with 2 wounds was 11.74 mm (from 79.01 mm to 90.75 mm). Coral growth rate was also not significantly different between the two treatments (P>0.05), with a range of 1.54-1.94 mm/month (wound 1) and 1.49-3.16 mm/month (wound 2). The growth rate increased after the corals recovered from wound healing (after 5 months of transplantation).
Applications of edible coating made from sago starchwith essential oil additives on tatihu fish fillet (Thunnus albacares)
Authors: Renur NM , Sutrisno  , Darmawati E , Nurjanah
Published: June 2022

Maluku is famous for its natural resources such as fish, sago, cloves, and nutmeg. Tatihu fish, otherwise known as yellowfin tuna. Essential oils are oils that consist of a mixture of liquid compounds obtained from the distillation of various plant parts. This study aimed to make an edible coating from sago starch with essential oil additives and its application to tatihu fish fillets. The first stage of this research was to isolate the essential oils of cloves and nutmeg, followed by determination of the antimicrobial substances from the essential oils before it was selected for fish spoilage bacteria and applied to the tatihu fish fillet. The extract yielded of the isolation of essential oils was 3.54% clove oil and 1.16% for nutmeg oil. Clove and nutmeg oil antibacterial test results gave positive results for E. coli and S. aureus. The MIC test results for clove oil and nutmeg oil against E. coli bacteria showed bacteriostatic activity with a minimum concentration of 0.195 and 12.5%, and against S. aureus bacteria by 0.098 and 25%, respectively. Edible coating application using 8% clove oil significantly affected the TPC and TVB values for different storage times.
Antibacterial activity of ethanolic Spirulina platensis extract-water soluble chitosan nanoparticles
Authors: Hardiningtyas Safrina Dyah , Putri Febby Amanda , Setyaningsih Iriani
Published: June 2022

Spirulina platensis is a microalga containing bioactive compound as antibacterial activity. The antibacterial compound from Spirulina can be used to treat bacterial infections on the skin such as acne. However, enhancement penetration of bioactive compounds through the skin was needed. The objective of this study was to determine bioactive compounds from Spirulina, synthesize Spirulina extract-water soluble chitosan nanoparticles using the ionic gelation method, and measure the antibacterial activity of Spirulina extract and its nanoparticles. For the synthesis of the nanoparticles, differences of Spirulina extract concentrations were used, including 3.25, 7.5, and 15 mg/mL. The yield of ethanolic Spirulina extract was 13.87±4.16% with the bioactive components of saponins, tannins, steroids, and phenols. The Spirulina extract-loaded chitosan nanoparticles were successfully fabricated with a nano-range size and narrow polydispersity. The amount of loading of Spirulina extract has affected the size and dispersion of nanoparticles. The antibacterial activity of nanoparticles showed higher than pure Spirulina extract only through Staphylococcus aureus and Pseudomonas aeruginosa, classified as moderate inhibition zones (5-10 mm). These suggested that nanoencapsulation could increase extract uptake on bacteria cells. The ethanolic Spirulina extract-chitosan nanoparticles have a potency for antibacterial agents on cosmeceutical products.
Pigments constituents, phenolic content and antioxidant activity of brown seaweed Sargassum sp
Authors: Sanger G , Wonggo D , Montolalu L A D Y , Dotulong V
Published: June 2022

Seaweed contains many biofunctional compounds such as pigment and antioxidants that have the utility to inhibit degenerative diseases that are caused by reactive species oxygen (ROS). This research aimed to measure the constituents of photosynthetic pigment and antioxidant activity of brown seaweed Sargassum sp. from North Sulawesi. Sargassum sp. was extracted using n-hexane, acetone, and ethanol by the maceration method. The research consisted of chlorophyll (a, b, and C1+C2), fucoxanthin, carotenoid, phycocyanin and phycoerythrin, total phenol content (TPC), scavenging radical activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP). The result exhibited that the hexane extract contained higher chlorophyll a and fucoxanthin than ethanol extract. The TPC values of acetone and ethanol extract of sargassum sp extract were 45.382 ± 3.023 and 44.885 ± 2.834 μg GAE (Galic Acid Equivalent) g-1 extract, respectively. Acetone extract of Sargassum sp. had a lower antioxidant activity of DPPH radical scavenger (IC50 2.966±0.178 mg mL-1) than ethanol extract IC50 2.684±0.256 mg mL-1 extract). The FRAP value of acetone and ethanolic extract of S.olygocystum were respectively 14.45±1.425 and 9.09±0.876 μM Fe2+ mg-1. The Sargassum extract is a potential natural source of natural pigment and antioxidant.
The effect of nest box type and stocking density on stratified shelf culture to increase earthworm Eisenia fetida biomass production
Authors: Mashur
Published: June 2022

Eisenia fetida is one of the species of earthworm that is widely cultivated commercially because the results of its cultivation are related to agriculture and industry. Eisenia fetida earthworm biomass production in the cultivation system applied by the cultivator community is still low. We need innovations in the application of cultivation technology. This research was conducted to determine the effect of the type of nest box, the density of the distribution of earthworms, and the use of multilevel rack cultivation system technology on the biomass production of Eisenia fetida. The research was conducted at the Earthworm Teaching Farm in Mandalika Village, Sandubaya District, Mataram City in January-March 2020. This study used an experimental method with a completely randomized design with a factorial pattern consisting of three factors, namely: three types of nest boxes, three levels of stocking density, and three levels of cultivation racks. The results showed that the type of nest box had a significant effect (P <0.05) on the percentage increase in biomass weight, but did not affect the percentage increase in the amount of biomass. The stocking density had a significant effect (P <0.05) on the percentage increase in the amount and weight of biomass. The level of cultivation rack did not affect the percentage of the number and weight of Eisenia fetida. The conclusion was that the average percentage increase in the highest amount of biomass was 175%/nest box, and the highest percentage increase in biomass weight of 344%/nest box was achieved in a plastic tub nest box with a stocking density of 25 grams of earthworms/nest box on the third tier cultivation rack. The average increase in weight of earthworm Eisenia fetida was 8.6% per day per nest box.
Development of fertilizer-based medium for the growth rate improvement of Chlorella sp. in the laboratory scale
Authors: Hidayati N A , Anggraini I D , Marno S , Fikri R A , Lathifah W , Putri N , Fitriani I N , Prabowo B , Fitriani R.
Published: June 2022

Microalgae are unicellular photosynthetic microorganisms, ubiquitous in nature which can be found in freshwater, seawater, hypersaline lakes, even in deserts and arctic ecosystems. Chlorella sp. is a eukaryotic, unicellular, photosynthetic organism with a spherical shape of about 1 to 20 μm in diameter. In this study, the combination of commonly used Walne medium and commercial fertilizers (ZA, TSP and Urea) were proposed as a low-cost approach for the cultivation of Chlorella sp. in the laboratory basis. The modified commercial fertilizer medium formulation consisted of the combination of at least 5% of Walne with different proportion of ZA, TSP and Urea. The result indicated that the combination of 5% (v/v) Walne and 95% (v/v) urea was able to retain the algal growth as compared to the combination of Urea, TSP and ZA. The obtained specific growth for 5% (v/v) Walne and 95% (v/v) urea modified medium was 0.246 d-1 and biomass productivity resulted 28 mg/L/d, which was comparable with commonly used Walne medium. Therefore, urea was primarily considered as the most suitable nitrogen source to support the growth of Chlorella sp. in the laboratory basis. Furthermore, modified commercial fertilizer medium developed in this study could potentially substitute the enriched medium used in the laboratory for the outdoor large-scale cultivation of microalgae.
Application of Modified Atmosphere Packaging to Extend Pineapple (Ananas Comosus L.) Shelf Life
Authors: Warsiki E , Manan K
Published: June 2022

The potential of pineapple (Ananas comosus L.) as export commodity both for fresh consumption and for the fruit processing industry has continue to increase. However, fresh pineapple can only be stored for 2-3 days at room temperature after ripening. On the other hand, the export process requires at least 35 days for delivering and retailing period. Long duration and distance is needed for fruit transportation thus it is required a special storage treatment to extend the shelf life. Modified atmosphere packaging has been proven to modify the air around the product to extend shelf life, especially fresh fruit and vegetable. In this study, modified atmosphere packaging technique was applied to whole pineapple using LDPE plastic. The amount of O2and CO2at various composition was tested and then the samples were storage at temperature of 7°C, 10°C and 28°C room temperature. The quality of the fruit was determined by the parameter of weight loss (%), hardness (mm/5s) and color. Control, pine apple was package without MAP, showed a significant quality deprived. Based on research, the best atmospheric composition to extend the shelf life of fresh pineapple was 1-3 % O2and 5-10 % CO2at 10 °C storage temperature. This condition gave a slow decrease in quality such as the weight loss was about 0.0296 %, the hardness value was 0.0393 mm/second and the organoleptic test was still under consumer’s acceptance.
Formulation of Bioethanol From Pineaple Skin Waste and Applicated as Wax Inhibitors
Authors: Fadly F , Afdhol M K , Hidayat F , Yuliusman Y , Nordin R M , Hasibuan R , Hakim F M
Published: June 2022

The problem of paraffin wax deposition is one of the problems that occurs in the oil industry which causes blockages during the oil production process. To prevent this problem, you can use a chemical method is injecting wax inhibitors. one of the effective wax inhibitors is solvent. So this paper aims to produce bioethanol solvent through biomass engineering, namely pineapple skin waste. For the production of bioethanol through several methods, namely pretreatment, hydrolysis which aims to convert cellulose into glucose with HCl acid, fermentation which aims to convert glucose into bioethanol with the help of saccaromyces cerevisiae yeast and finally distillation. The result in the hydrolysis process with concentrations of HCl 1M, 2M, 3M, 4M and 5M produces glucose 7 Brix, 16 Brix, 20 Brix, 21 Brix and 24 Brix. And with variations in heating time of 1 hour to 5 hours, the optimum glucose was obtained at 3 hours of 24 Brix. The results of fermentation with a variation of 1 day to 6 days, the optimum bioethanol content in fermentation for 3 days is 18%. 18% bioethanol is mixed into waxy crude oil with a pour point value of 43°C, and the result is able to reduce the pour point is 3°C. To increase the decrease in the pour point of bioethanol, it is blend with a toluene, and the result is to reduce the pour point value by 8°C. So it can be concluded that mixing bioethanol and toluene as a solvent can inhibit paraffin wax deposition