bluuebunny/crossref_metadata_2025 huggingface dataset:
2D Mapping of Mobile Robot Based on micro-ROS
Authors: Li Bin , Ma Zhengguang , Zhao Yongguo
Published: December 2022

This paper proposes micro-ROS-based mobile robot system development and 2D mapping. Micro-ROS uses the micro-XRCE-DDS middleware to communicate with ROS2 in an extremely resource-constrained microcontroller environment. The mobile robot control system adopts a layered control method. The x64 PC equipped with Ubuntu ROS foxy is used as the main control platform, the olimex-stm32-E407 equipped with micro-ROS is used as the motion control layer, and the stm32F103 microcontroller is the underlying driver core. The forward and inverse kinematic equations are obtained through the analysis of the robot kinematics model. Through the interaction between the ROS2 nodes in the micro-ROS environment and the ROS2 nodes on the PC side, the cartographer algorithm is used to verify the effectiveness of the micro-ROS-based mobile robot system.
A Variable Stiffness Exosuit for Walking Assistance
Authors: Huang Kaizhen , Xu Jiajun , Lu Yonghua , Xu Linsen
Published: December 2022

Robotic exoskeleton takes an important role in walking assistance for subjects with lower extremity impairment. However, most of the existing robotic exoskeletons are bulky and complicated in the mechanical structure, placing a large load on the wearer. In this paper, a soft exosuit with twisted string actuators (TSAs) is designed for walking assistance. The analytic model of the TSA is derived to prove its characteristic of variable stiffness, benefited from which, flexible and compliant assistive torque can be generated to knee joints whilst walking. Furthermore, a human-robot coupling dynamic model is established, and an admittance control strategy is utilized to improve the trajectory tracking performance. Finally, simulations are conducted to verify the proposed robot system.
Designing Control System of Palletizing Robot Based on RobotStudio
Authors: Chen Xiaokang , Zhou Yin , Yang Bin , Miao Xinghua , Li Yanlin , Zhang Miaorong
Published: December 2022

According to the operational task of the palletizing robot in the intelligent manufacturing system, the layout and control process of the palletizing system are first designed. And then, the Smart Component of RobotStudio is used to design the system signal with I/O control logic, conveyor control logic, and a suction cup tool. Finally, the rationality, efficiency, and convenience of the function of the palletizing robot control system are verified by building a palletizing simulation system.
Assembly Status Detection Based on Step-by-step Strategy for Robotic Assembly
Authors: Cui Jia , Bie Haodong , Yao Bitao , Xu Wenjun
Published: December 2022

Assembly status detection is of great significance in the automated assembly of industrial robots. However, in addition to the traditional manual inspection, the existing methods for assembly status detection are mainly through methods such as torque sensors, etc., which are difficult to implement in practical assembly and lack the detection of the entire assembly cycle. To solve this problem, this paper proposes a method for assembly statute detection based on a step-by-step strategy. The first step is to use fast bounding box collision detection to determine whether the robot enters the correct assembly neighborhood. The second step is to use accurate pose information to determine whether the product is assembled correctly. The experiments show that the proposed method can accurately detect the assembly status for the entire assembly cycle with high assembly efficiency.
Multi-robot Coordination for Environment Exploration and Patrol
Authors: Yang Jianxin
Published: December 2022

With the development of manufacturing, people benefit from using multiple mobile robots to complete tasks in various scenarios, and multi-robot planning coordination has become a hot research topic in recent decades. This paper introduces two popular multi-robot system applications: multi-robot exploration and multi-robot patrol. First, the two kinds of problems are introduced and compared. Then, typical methods to figure out the problems are presented, including the frontier-based and market-based methods for exploration and the v-Min algorithm and v-Neighbor algorithm for patrol. Finally, this paper gives the experiment results and conclusions of different methods.
Study on the determination of variable characteristics of axial piston pumps
Authors: Yuan Chenhui , Xing Keli , Jin Xiajie
Published: December 2022

Because the variable characteristics of axial piston variable pump can be applied to different working conditions, this paper simulates the actual working conditions of axial piston pump in excavator, theoretically analyzes its variable working principle, and focuses on how to adjust the difference between pump outlet pressure and load sensitive port pressure stably. Finally, an axial piston pump variable characteristic test system is built based on LabVIEW software, and a field verification test is conducted, and an effective and reasonable test scheme is selected through analysis and comparison, which provides a certain engineering reference value for the variable characteristic test of axial piston pump.
A Hybrid Model Based on Jensen’s Inequality Theory for 3D Printed Lattice Structures Maximum Stress Prediction
Authors: Zhang Zhiwei , Zhang Yuyan , Wen Yintang , Ren Yaxue
Published: December 2022

Inherent defects in 3D-printed metal lattice structures are inevitable and significantly affect the structural part’s maximum stress. To solve this problem, a hybrid model based on Jensen’s Inequality Theory to predict the maximum stress of 3D printed lattice structures is proposed in this study. Jensen’s inequality theory means that the average of the model predictions will not be lower than the predictions of the individual prediction models. Therefore, the optimal number of hybrid models is discussed and designed, and the optimal base estimators are trained and selected on the same dataset. A hyperparametric approach is used to optimise the base estimator parameters. The experimental results demonstrate that the hybrid model performs better than a single estimator’s prediction, with an R2 of 0.83. This research offers a novel approach for the prediction of 3D-printed lattice structures using machine learning.
Mechanism and regulation of high temperature and high salt tolerance polymer polymerization behavior
Authors: Song Liping , Zhao Xingze , Wu Yining , Ren Hao
Published: December 2022

In this study, the molecular dynamics simulation of imidazole-modified polyacrylamide (VPAM) and polyacrylamide (PAM) system showed that the VPAM system containing imidazole-modified polyacrylamide (VPAM) had better cohesion-bonding effect than the PAM system without imidazole. Based on the imidazole-containing VPAM system, the cohesion properties of the functional monomers and the mechanism of the functional monomers in the process of cohesion were analyzed at high temperature and high salt, and the structure-activity relationships between the chemical structure of the functional monomers and the ratio of polymer monomers and the apparent cohesion properties were obtained.
Smooth Surface Defect Detection of Metal Workpiece Based on Digital Speckle Pattern Interferometry
Authors: Jia Mianqian
Published: December 2022

When the existing defect detection methods are used to detect the defects on the smooth surface of metal workpieces, there is a big difference between the detection results and the actual results, and the detection accuracy is low. Therefore, the digital speckle pattern interferometry (DSPI) technology is introduced in this paper to study the design of the detection method of smooth surface defects of the metal workpieces. In this paper, the smooth surface of metal workpiece is measured by using digital speckle interferometry. The speckle on the measurement image is processed by the Laplace algorithm, and the speckled area is automatically extracted; The defects on the smooth surface of the metal workpiece are detected and located according to the speckled area. The comparative experiments show that the detection errors of the two new detection methods are less than 0.1 µm in practical application, and the detection accuracy is high, which can realize the high-precision detection of smooth surface defects of metal workpieces.
Analysis and Diagnosis of Rolling Bearing Faults from the Perspective of Frequency Domain
Authors: Chen Bin , Li Yunxin , Lv Rongxin , Sheng Aitong , Wang Xiaorui , Li Junyi
Published: December 2022

Rolling bearing components are broadly utilized in major mechanical fabricating businesses and guaranteeing the secure and steady operation of rolling heading could be a basic necessity of the fabricating prepare. Engineering for intelligent manufacturing has grown significantly in importance during the past several years in the manufacturing sector. The method for identifying mechanical faults based on “frequency domain analysis plus intelligent model” has developed rapidly. In this study, methods such as envelope spectrum analysis and spectral kurtosis are applied to process and analyze fault data to improve the service life of rolling bearing production equipment. In addition, we perform grid search tuning of the hyperparameters in spectral kurtosis, enabling faster frequency band selection for envelope spectral bandpass filtering.
Failure Analysis of The Weld in Shale Gas Gathering Pipeline
Authors: Bao Mingyu , Gao Jian , Liu Chang , Sun Mingnan , Chen Yanjun , Wang Qiliang
Published: December 2022

Perforations occurred at the weld of a shale gas gathering pipeline in Shunan gas field. In order to explore the specific causes of weld failure, this paper carried out analysis by means of Macroscopic detection, Mechanics property analysis, Metallographic analysis, Scanning electron microscopy (SEM), Energy spectrum analysis (EDS) and other means. The analysis results show that CO2 corrosion is the main cause of weld failure of flat shale gas gathering pipeline. In addition, there are obvious defects in the weld and large residual stress, coupled with the presence of S element, which directly aggravate the corrosion perforation of the weld. In this paper, the specific reasons for weld failure of a shale gas gathering pipeline in Shunan gas field are explored, which can provide some reference for anti-corrosion of shale gas gathering pipeline.
Optimization Design of Landing Gear Structure based on Fatigue Life Constraint
Authors: Wu Binbin , Shi Yan , Yin Yin
Published: December 2022

To decrease the weight of the landing gear and expand the application area of the optimization method with fatigue life constraint in complex mechanisms, the optimization models of the landing gear with fatigue life and stress as constraints are established, respectively. The comparison results show that the optimization results with fatigue life as a constraint are more reasonable, as stress and life requirements of the landing gear can be taken into account simultaneously. Finally, the static test was carried out to verify the accuracy of the optimization results. Test results indicate that the optimization method based on fatigue life constraint has good applicability and application value in practical engineering.
Comprehensive assessment of equipment maintainability testability and supportability
Authors: Quan Li , Liu Baoding , Liu Haigang , Yu Jinsong , Li Xin
Published: December 2022

General quality characteristics can reflect the performance and quality of equipment and have great guiding significance for the design, production, trade, and use of equipment. Maintainability, testability, and supportability (MTS) are all related to equipment faults and maintenance support and have strong relevance between them. Solving the problem of the isolation of the three characteristics evaluation requires to reduce the duplication of work and improve the evaluation efficiency, comprehensively assessment methods based on model and test are proposed by analysing the correlation of the MTS parameters. In the case study, parameters of different characteristics are obtained instead of one single characteristic, which shows the effectiveness of the proposed methods compared with the traditional sequential assessment method.
The simulation analysis of sealing performance of cone-cone premium tubing connection under combined loads
Authors: Yu Yang , Qu Zhan , Cao Yinping , Dou Yihua
Published: December 2022

Under the complex downhole loads, premium tubing connections often suffer from seal failure and threaded connection failure, leading to tubing string leakage and even safety accidents. Therefore, this paper focuses on the cone-cone premium tubing connection, simulating the make-up process and downhole load conditions, establishing three dimensional finite element models of premium tubing connections, analyzing the distribution of equivalent stress and contact pressure on sealing surface, shoulder and thread. The results show that the stress is mainly concentrated on the shoulder and sealing surface under the make-up torque. The equivalent stress on the shoulder shows a trend of increasing first and then stabilizing. The equivalent stress at the sealing surface tends to be stable first and then decreases. Under the combined loads, the overall equivalent stress of connection increases. The contact pressure decreases slightly in the area of sealing surface and the shoulder inflection point. It may cause joint failure and leakage, when the internal pressure is over 80MPa and the axial compressive load is greater than 800kN, which will lead to the maximum equivalent stress of the threaded part exceed 5.5% of the yield strength.
Current status and suggestions of satellite borne single-phase fluid loops
Authors: Liu Qingzhi , Huang Lei , Yi Hua
Published: December 2022

Enhancement of the load function and diversification put forward higher requirements for thermal control mode and the thermal rejection ability of the satellite. Limited to size, heat transfer efficiency, and mission characteristics of the satellite, thermal rejection ability has increasingly become one of the most important factors which restrict the mission of the satellite, and technical advantages and potential application of the single-phase fluid loops have become increasingly prominent. The single-phase fluid loop has been applied to China’s satellite field several times and has played an important role in long-distance heat transfer, expanding thermal rejection ability and improving system control ability. This paper describes the current application status of the single-phase fluid loops in China’s satellite field in recent years and provides some suggestions for developing and applying the single-phase fluid loops in the future. The single-phase fluid loop has become one of the important options for satellites with high power and distributed heat sources. Weight, layout, and micro-vibration are the major limited elements for space application, which should be further studied. Research on the high integration of products, new products, and vibration isolation technology is helpful and necessary.
A review of methods for calculating of the interfacial heat transfer coefficient
Authors: Lin Xiyue , Li Xianjun , Zhang Wenliang , Luo Ping , Liang Xiao , Chen Jiaheng , Yang Jie
Published: December 2022

As an important parameter for quenching and simulation, the interfacial heat transfer coefficient (IHTC) is hard to be directly measured through experiments. Researchers have come up with different methods to solve the problem. Currently, the numerical method, the heat balance method (HBM), the Beck’s non-linear estimation method (BEM), and the lumped heat capacity method (LCM) are the main methods of calculating the IHTC. In this paper, the direct heat conduction problem and the solution are firstly analysed, then the solutions and applications of different methods for calculating IHTC are summarized and reviewed. The different methods are compared at the end of the paper.
Study on fracture analysis of rotor blade in thermal power plant
Authors: Lyu Lei , Tu Anqi , Wang Yingjun
Published: December 2022

The comprehensive failure analysis of the fractured LP rotor blade was carried out by means of appearance morphology analysis, SEM morphology analysis, mechanical property analysis, chemical composition analysis and microstructure detection. The results show that the second and last stage blades at the low-pressure rotor turbine side are damaged by mechanical collision, resulting in damage and deformation at the steam outlet side of the blades and generating stress concentration areas. The blades are prone to generate crack sources in the stress concentration areas of mechanical damage under the working load, and the cracks continue to expand on the condition of alternative stress, eventually leading to fatigue cracking and fracture of the blades. It is recommended to carefully check the blades at other positions of the LP rotor and deal with the mechanical damage and cracking problems in time. Secondly, foreign matters shall be prevented from entering the turbine with the steam to damage the blades, and the fixed parts inside the cylinder shall be ensured to be firm and not fall off, so as to prevent the recurrence of similar blade fracture.
Multi-objective optimization method for distributed energy storage configuration under distribution network operation constraints
Authors: Long Wen , Zhu Bin , Li Huaizheng , Yang Fan , Peng Wenxin , Wang Qiang
Published: December 2022

The multi-objective optimization method for distributed energy storage configuration has the problem of high network loss expectation. A multi-objective optimization method for distributed energy storage configuration under distribution network operation constraints is designed to solve the above problems. The intra-day charge/discharge balance is used as a criterion to identify the characteristics of distributed energy storage configuration, calculate the network loss sensitivity of nodes, construct a siting and capacity setting model, and integrate multiple power quality indicators to improve the multi-objective optimization model under the distribution network operation constraint. The experimental results show that the mean values of network loss expectations for the distributed energy storage configuration multi-objective optimization method in the paper and the other two distributed energy storage configuration multi-objective optimization methods are: 226.731 kW, 270.762 kW, and 276.728 kW, respectively, indicating that the designed distributed energy storage configuration multi-objective optimization method is more feasible after fully considering the distribution network operation constraints.
Research on Power Prediction of Runoff Small Hydropower Cluster Based on Fusion Modeling
Authors: Zhang Feng , Zhang Yi , Qiu Yutao , Wu Xiaogang , Tao Yufeng , Ji Qingfeng , Xie Xiahui
Published: December 2022

The characteristics of the runoff hydropower station are to generate power completely according to the natural runoff, and the output and power generation change with the change of the natural flow. The cluster power prediction of the runoff hydropower station is conducive to improving the safety of the power grid operation and improving the utilization rate of hydropower. This paper analyzes the operation characteristics of runoff hydropower stations, summarizes the prediction direction of mainstream runoff hydropower, analyzes the characteristics of the hydrological prediction model represented by the Xin'an River model, and puts forward a study on the power prediction technology of runoff small hydropower cluster based on fusion modeling. Based on the detailed analysis of watershed runoff characteristics, a prediction model based on multi-watershed observation characteristics is proposed, which combines the traditional hydrological model with the LSTM model to form a combined prediction model suitable for runoff hydropower. The method is universal and innovative.
Numerical simulation of the effect of rib spacing on the heat transfer performance of micro pin-fin heat sink
Authors: Sun Hongwei Zhu Huan , Xu Haorong
Published: December 2022

This paper aims to deeply understand the influence of different columnar rib spacing on the comprehensive thermal hydraulic performance of miniature columnar rib radiator, and further explore the influence of flow and heat flow density Taking 10 miniature columnar rib radiator models as research objects, the single-phase heat transfer process of square miniature columnar rib radiator was studied. The experimental results show that for 10 kinds of miniature columnar rib radiators, the relationship between the maximum temperature difference at the bottom of the ribbed substrate will change with the change of temperature, with linear arrangement and cross arrangement.The maximum and minimum values are, respectively, when the longitudinal spacing is 0.75mm and 0.25 mm, and the maximum and minimum values are, respectively, when the transverse spacing is 0.5 mm and 1.25 mm.
Joint optimization method of electric boiler, heat storage device, CHP and wind power under market environment
Authors: Zhang Yumeng
Published: December 2022

CHP can make more efficient use of energy by combining heat and electricity, and more and more places choose this type of heating. Taking use of CHP for the consumptive power of clean energy has great significance in solving current issues of abandoning wind or light. While due to the physical constraints “set power by heat” of CHP, the regulation ability of the unit is weakened. This paper proposes to apply the heat storage device to CHP to enable CHP can meet heating demand while participating in the deep peak shaving market, to realize the targets of the consumptive power of clean energy and the increment of combined unit profits.
Dynamic Economic Environmental Dispatch of Power System Using An Improved Whale Algorithm
Authors: Lou Jiale , Li Lingling
Published: December 2022

With the global energy crisis and environmental problems becoming increasingly serious, the construction of a new power system containing multiple renewable energy sources for power generation has become a current research direction. In this study, a dynamic economic environmental dispatch model for power systems containing wind and thermal power generation is proposed to promote renewable energy consumption while ensuring system power balance. Firstly, a comprehensive objective function that integrates system operating costs and pollutant emission targets is established, and system active balance constraints and unit output constraints are considered. Secondly, an improved whale optimization algorithm is proposed to deal with the solution problem of the dynamic economic environmental dispatch model by introducing circle chaos mapping, dynamic sine cosine factor, and polynomial variation strategy. Finally, the optimization capability of the proposed model is verified by running a unit test system. The proposed model promotes the consumption and utilization of wind and photovoltaic resources and positively impacts achieving carbon peaking and carbon neutrality.
Mixture Density Network Based on Truncated Distribution and Genetic Algorithm For Wind Power Forecasting
Authors: She Wei , Zhang Renzhong , Liu Wei , Zhong Lihong , Chen Bin , Tian Zhao
Published: December 2022

Due to the excellent wind power probabilistic prediction performance, Mixture Density Network (MDN) is used in short-term wind power forecasting, but the density leakage problem the Not a Number (NaN) loss problem and the choice of hyperparameters in the MDN seriously affect the model performance. GA-TDMDN is proposed in this paper for wind power probabilistic forecasting. GA-TDMDN uses truncated distribution as kernel function to solve density leakage. For the NaN loss problem that occurs during model training, different output layer activation methods and improved loss function are used for different mixture component parameters, so that the shape of the truncated normal distribution can be better controlled. Genetic Algorithms (GA) is used to optimize key hyperparameters in the MDN structure. The experimental results show that it is feasible to use truncated distribution to solve the density leakage problem, and using the GA algorithm to optimize the model structure can improve the model performance
CMS Outer Tracker Phase-2 Upgrade module noise and mitigation
Authors: Zografos A. , Blanchot G. , Kovacs M. , Maier S. , Mateos I. , Pauls A. , Schleidweiler K.
Published: December 2022

The CMS Outer Tracker phase-2 upgrade silicon modules are required to reach noise levels close to the ones expected from the analogue front-end attached to an ideal pixel/strip. Module prototypes, featuring the latest and final prototype hybrids before the production, showed noise that was higher than the expected which could pose a problem in terms of achieving the hit efficiency target. Investigations, reveal the failure modes which are modelled in order to guide mitigation tweaks for the production designs. Knowledge acquired from the investigations along with the noise mitigation design changes implemented on the production hybrids are presented.
Laser photo-ionization study of
nat
Ag using opto-galvanic signal at SPES offline laser lab
Authors: Khwairakpam O.S. , Mariotti E. , Scarpa D. , Nicolosi P. , Khanbekyan A. , Arzenton A. , Ferracane S. , Andrighetto A.
Published: December 2022

Resonant Ionization Laser Ion Source (RILIS) is one of the most advancing techniques for the production of radioactive ion beams (RIBs) in ISOL facilities. SPES project at INFN-LNL is a second generation ISOL facility which aims to produce several isotopes in a couple of years. Within the framework of this project, resonant photo-ionization schemes of several elements are studied in the offline laser lab, to be later implemented in the SPES Laser Ion Source. Silver is one of the elements being studied for the stated purpose. In this article, we report a resonant photo-ionization scheme of silver tested with a hollow cathode lamp (HCL). Evidence of high lying Rydberg states around 60945.32 cm−1 has also been observed by studying the fast opto-galvanic signal detected.
Much of zero emissions commitment occurs before reaching net zero emissions
Authors: Koven Charles D , Sanderson Benjamin M , Swann Abigail L S
Published: December 2022

We explore the response of the Earth’s coupled climate and carbon system to an idealized sequential addition and removal of CO2 to the atmosphere, following a symmetric and continuous emissions pathway, in contrast to the discontinuous emissions pathways that have largely informed our understanding of the climate response to net zero and net negative emissions to date. We find, using both an Earth system model and an ensemble of simple climate model realizations, that warming during the emissions reduction and negative emissions phases is defined by a combination of a proportionality of warming to cumulative emissions characterized by the transient climate response to emissions (TCRE), and a deviation from that proportionality that is governed by the zero emissions commitment (ZEC). About half of the ZEC is realized before reaching zero emissions, and the ZEC thus also controls the timing between peak cumulative CO2 emissions and peak temperature, such that peak temperature may occur before peak cumulative emissions if ZEC is negative, underscoring the importance of ZEC in climate policies aimed to limit peak warming. Thus we argue that ZEC is better defined as the committed warming relative to the expected TCRE proportionality, rather than as the additional committed warming that will occur after reaching net zero CO2 emissions. Once established, the combined TCRE and ZEC relationship holds almost to complete removal of prior cumulative CO2 emissions. As cumulative CO2 emissions approach zero through negative CO2 emissions, CO2 concentrations drop below preindustrial values, while residual long-term climate change continues, governed by multicentennial dynamical processes.
Vegetation disturbances characterization in the Tibetan Plateau from 1986 to 2018 using Landsat time series and field observations
Authors: Wang Yanyu , Ma Ziqiang , He Yuhong , Yu Wu , Chang Jinfeng , Peng Dailiang , Min Xiaoxiao , Guo Hancheng , Xiao Yi , Gao Lingfang , Shi Zhou
Published: December 2022

Disturbances in vegetated land could dramatically affect the process of vegetation growth and reshape the land cover state. The overall greenup of vegetation on the Tibetan Plateau (TP) has almost served as a consensus to date. However, we still lack consistent acquisitions on the timing, the spatial patterns, and the temporal frequency of vegetation disturbance over the TP, limiting the capacity for planning land management strategies. Therefore, we explored the spatiotemporal pattern and variation of vegetation disturbances across the TP during the past decades and analyzed the disturbance agents. We utilized 37-year Landsat time series images and field observations coupled with a temporal segmentation approach to characterize the spatiotemporal pattern of vegetation disturbances across the TP for the period 1986–2018. The results from this study revealed that 75.71 M ha (accounting for 29.34% of TP’s area) vegetation area underwent at least one disturbance, of which 8.44 M ha area ever experienced large-scale disturbances (disturbance area greater than 0.9 ha and disturbance magnitude (the difference between the spectral value of pre-disturbance and that of post-disturbance) over 0.2). Further, the spatial distributions of these large-scale disturbances varied over time: before 2002, the disturbed sites were evenly distributed over the southeast part of the TP probably induced by overgrazing and unscientific livestock management, while after 2002, most disturbances were concentrated in the south of the Yarlung Tsangpo, mainly caused by anthropogenic activities, such as urban area, roadways, railway, and water control projects. This study presents an effort to characterize vegetation disturbances and their variations over the past decades on the TP, which provides crucial insights toward a complete understanding of vegetation dynamics and its causal relationship with human activities.
Shorebird community and diversity in Bagan Serdang Beach, North Sumatra
Authors: Jumilawaty E , Nasution A L A , Siregar S
Published: December 2022

The occurrence of shorebirds is strongly influenced by environmental factors, especially food availability. Shorebirds are closely linked to their habitat conditions, so they seek out feeding sites according to their life cycle. Coastal conditions that have changed due to human activities may affect the assemblage of shorebird community. The aim of this study is to determine the diversity of shorebird species and the factors that influence them. Bird observations were made for three days using the point count method while the number of individuals was estimated by using “block method”. The results revealed 17 shorebird species from the families, Charadriidae, Scolopacidae and Sternidae. The dominant species were Charadrius mongolus, Pluvialis fulva and Sterna hirundo. The number of species in the morning observations was higher than in the afternoon. The diversity index for migratory birds ranges from 1.16 to 1.96, which is relatively low. This study showed that mudflats in Bagan Serdang Beach, Pantai Labu District is occupied by shorebirds in this region.
Welfare management of Sumatran Tiger (Panthera tigris sumatrae) in Medan Zoo and Siantar Zoo
Authors: Zahrah M , Ulfa M , Saragih R P
Published: December 2022

Panthera tigris sumatraeis one of endemic species of Sumatera Island included in the endangered species red list by the IUCN. The efforts to preserve the sumatran tiger is with conservation activities both in-situ and ex-situ. One form of ex-situ conservation is to keep animals in the zoos. This study aims to assess the welfare level of Sumatran tigers are in Medan Zoo and Siantar Zoo. Aspects of tiger welfare are measured through 5 variables basedon five animal freedom, namely the free of hunger and thirst, the free of environmental discomfort, the free of pain, wounds and diseases, the free of natural behavior and the free of fear and suffering. Data collection through direct observation of animal management and assessment of minimum animal welfare standards. Interviews with veterinarians and animal keepers about human resources and management activities carried out in supporting animal welfare. The assessment is carried out by the management, namely veterinarians, animal keepers, researchers and visitors to obtain objective results. The implementation of sumatran tiger welfare management in Medan Zoo has an average of 76.9 with the category is good and for Siantar Zoo has an average of 95 with the category is very good. Recommendation that needs to be considered from the results of this study is that Medan Zoo needs to add enrichment in the cages that tigers can behave naturally.
Stock Assessment of Indian Mackerel (Rastrelliger kanagurta) Landed at Tanjung Beringin’s Auction Place Serdang Bedagai, Sumatera Utara
Authors: Hasibuan J S , Sidabutar M A P , Sinaga J , Desrita  , Manurung V R
Published: December 2022

Indian Mackerel (Rastrelliger kanagurta) is one of the main catch fishery at Tanjung Beringin’s Auction Place, Serdang Bedagai, Sumatera Utara. The purpose of this research is to analyze the stock status of indian mackerel landed at Tanjung Beringin. This research was conduted in July – September 2021. The method of research used purposive sampling method. The total sample fish of indian mackerel were 272 individuals. The research showed Indian mackerel’s sex ratio was 1: 1.060. Indian mackerel’s growth pattern was negative allometric. Value estimation of male and female’s L∞ was 268.80 mm and 295.05 mm. Value K of male mackerel was bigger than female. But value of Lc and Lm male mackerel were smaller than female. The total rate of mortality was 2.466/year, natural mortality was 0.684/year and fishing mortality (F) was 1.782/year. The rate of exploitation was 0,723 classified as high exploitation level (overfishing).
Composition and diversity of tropical forest vegetation at Sibolangit tourism park, North Sumatra, Indonesia
Authors: Ulfa M , Harahap M M , Rambey R , Ritonga Y E , Zahirah A , Silalahi R R , Sitinjak A R
Published: December 2022

Vegetation is an important component of preventing erosion and drought, regulating water and hydrology, improving soil physical, chemical, and biological properties, balancing the carbon dioxide and oxygen in the air, conserving biodiversity, effecting other biota in ecosystem, and supporting the ecotourism potential. The effect varies depending on the structure and composition of the plants that comprise the area's vegetation formation. Sibolangit tourism park, with an area of 24.85 Ha, was established in 1980 by Minister of Agriculture Decree No. 636/Kpts/Um/1980. This study aims to examine the importance value index and diversity index of species in the Sibolangit tourism park area. The data was sampled using a simple random sampling method with a 5% sampling intensity. The observation plots were randomly placed to cover all the study sites. Species, diameter, height, and the number of each individual were recorded during field observation. The study recorded a total of 67 species in Sibolangit Tourism Park. The dominant species at the tree stage wasPterocarpus indicuswith an IVI of 28%.Mitrephora obtusawas the dominant species at the pole and sapling stages with the IVI of 52% and 35%, respectively. At the seedling stage,Strombosia ceylanicawas the dominant with an IVI of 62%. The vegetation diversity at the study site was in the moderate range with the 2.71 of Shannon-Wiener diversity index.
Assessment of the tree damage level in Medan Beringin Park
Authors: Harahap M M , Ahmad A G , Simatupang J , Ulfa M , Wirabuana P Y A P
Published: December 2022

Medan is the capital city of North Sumatra Province and the biggest city on the island of Sumatra. Big cities in Indonesia generally have problems with environmental degradation. One of the efforts to preserve the environment in urban areas is to provide public green spaces dominated by trees. In the process of its life, the tree experiences many disturbances and interventions from the surrounding environment. It can make it grow abnormally or become sick. One of the negative impacts of this is when extreme weather occurs and causes trees to break easily, fall, and fall on whatever is underneath. It can cause various material losses and even fatalities. The research has conducted at Beringin Park in Medan. It is one of the favorite places for people to gather and enjoy the freshness of clean air. Research on tree health surveys and inventories in public green spaces is important to do as one of the efforts to mitigate the occurrence of fallen tree disasters. This research is aimed to take an inventory of tree health in Beringin Park as an mitigation effort of the fallen tree disaster in Medan. Vegetation parameters were collected by using the census method at the pole and tree stage. The Shannon – Wienner diversity index has used to assess the biodiversity level of the research location. Then damage level index was analyzed by using Forest Health Monitoring Method. The results showed that the tree vegetation in Beringin Park was in the healthy category based on the Tree Damage Index Value which ranged from 1.20 to 4.10.
Mapping and Population Structure of Shorea platyclados in Martelu Purba Nature Reserve
Authors: Hartini KS , Rangkuti AB , Manalu BP , Andini SW , Insani A
Published: December 2022

In its natural habitat, S. platyclados is abundant in Martelu Purba Nature Reserve, North Sumatra. However, like the Dipterocarpaceae family, this species has limitations in regeneration related to the uncertain flowering phase and the seeds' recalcitrant nature. This condition can be a long-term threat to the sustainability of S. platyclados. Efforts should be made to select mother plants as a source of short-term quality seeds, to support the breeding program and the conservation of S. platyclados. Monitoring of mother plants will be more effective if mapping data is available. Therefore, it is important to map the mother plant of S. platyclados. In addition, the population structure needs to be identified and related to trends in its sustainability. The goal of this study was to map the mother plant of S. platyclados in Martelu Purba Nature Reserve and to examine its population dynamics.. This research was conducted in Martelu Purba Nature Reserve, Simalungun Regency, North Sumatra. There are 195 hectares of designated population there. Combining the path method and the plotline, the sampling methodology was applied. Fifty (50) plots were observed across the sample area of 2 hectares (1% Sampling Intensity), which was separated into three lanes. Observations were made on a 20 m × 20 m plot to measure the vegetation at the tree level (diameter 20 cm), a 10 m × 10 m observation sub-plot to measure the vegetation at the pole level (diameter 10cm - 20m), a 5 m × 5 m observation sub-plot to measure the vegetation at the sapling level (diameter 10 cm), and a 2 m × 2 m observation sub-plot to measure the vegetation at the seedling level. The mother plants were recorded as many as 309 individuals in 50 observation plots, or 155 individuals/ha spread evenly in the relatively sloping Nature Reserve area. The distribution structure of the height and diameter of the mother plants indicates a good adaptation, resembles a standard curve. The population structure of S. platyclados is curved like an inverted J, indicates that this population is quite stable and sustainable. However, monitoring at the pole level is crucial based on a gap in the presence of this regeneration compared to others.
Manifestation of endoparasitic helminths in Sumba Horse (Equus caballus) in Citra Pesona Ladangku Animal Park
Authors: Sinaga L , Tanjung M
Published: December 2022

Gastrointestinal parasitic infections can cause horses to experience diarrhea, weight loss, weakened physical condition and even death. This horse disease is a great danger that can reduce horse performance.The research on the description of gastrointestinal endoparasites in Sumba horses (Equus caballus) at Citra Pesona Ladangku animal park, Pancur Batu, Deli Serdang, North Sumatra. The aim of the study was to determine the type of endoparasites, prevalence and the intensity of parasite attacks. The sample testing was carried out at the Parasitology Laboratory, Medan Veterinary Center using the EPG Mc. Masters method. The results showed that from 18 Sumba horses examined, 6 types of endoparasites were found, namely Strongylus sp., Trichonema sp., Dictyocaulus arnfieldi, Strongyloides sp., Triodontophorus sp. and Ascaris sp. The prevalence of Strongylus sp. was 86% in the usual category and the intensity attack was 1.530 in the Super infection category, Dictyocaulus arnfieldi was 53% in the frequent category and the intensity attack was 1.161 in the Super infection category, Trichonema sp. was 38% in the common category, and the intensity attack 300 categorized in the very severe category, Strongyloides sp. was 22% in the often category and the intensity was 430 in the very severe category, Triodontophorus sp. was 16% in the often category and the intensity was 500 in the very severe category and Ascaris sp. had prevalence 14% in the often category and the intensity was 100 in the severe category. The gastrointestinal parasitic infections in Sumba horses need special attention.
Forest structure change after forest fire in peatland of Central Kalimantan
Authors: Qirom M A , Rachmanadi D , Lestari F , Andriani S
Published: December 2022

The hydrological system of tropical peatland has been changed due to drainage. The condition caused prone to peatland burning. Forest fire affected the vegetation composition in peatland. Repeated fire causes more severe impact on vegetation and the change the peatland characteristics. The aim of the study is to obtain species composition on peatland after fire in Central Kalimantan. The research was conducted on several plots of vegetation observation on peatland that burned in 2015 (three years after fire and forth fire frequency). The plot sizes were depending on vegetation stage (seedling, sapling, poles, and trees) of 2 Ha or 50 observation plots. The measurements of parameter were species, density, frequency, and important value index. The species composition was described by ecological indices such as Shannon wiener index, Simpson index, and evenness index. The results showed that species diversity and ecological index were very low. That condition indicated that the fire has changed the species composition and the natural regeneration has been obstructed. Combretocarpus Rotundatus and Cratoxylon glaucum were presented on overall tree stage as pioneer species, but the climax species didn’t found on three years after forest fire. Based on the results, the repeated fires caused an extreme decrease of natural regeneration so the ability of recovery is not running well. The parameters can be used in determining the priority of revegetation program on large scale.
Species checklist of Orthoptera in the Forest Area with Special Purpose (KHDTK) Aek Nauli, North Sumatra
Authors: Siahaan D A S , Nursal  , Alfakih I R , Dzawita Y , Zahra F , Harianja M J , Hartanto A
Published: December 2022

We present the species checklist of Orthoptera in the Forest Area with Special Purpose/KHDTK Aek Nauli, Simalungun Regency, North Sumatra, Indonesia. The checklist is provided as a basic information on the grasshopper diversity and species assemblage in the forest region. KHDTK Aek Nauli is classified into a tropical montane forest with an elevation of 1,100–1,750 m a.s.l dominated by the pine species and intended as an ex situ conservation for Sumatran Elephant (Elephas maximus sumatranus). Sampling of grasshoppers was conducted for four consecutive days using two methods namely pit fall trap and sweeping net with a total of 12 sampling points. Approximately of 21 orthopteran species from 97 individuals belonging to suborder Ensifera (12 species) and suborder Caelifera (9 species) were documented. The highest Importance Value Index (IVI) orthopteran species was obtained from Paratettix curtipennis (102.92), followed by Teleogryllus emma (79.04), Oxya intricata (69.67), and etc. All grasshoppers were commonly identified for Asiatic region to worldwide distribution.
Identification of the generative phases of Amorphophallus gigas in the Sabungan Village and Langga Payung Village, Sungai Kanan District, North Sumatra Province, Indonesia
Authors: Rambey R , Rahmawaty  , Rauf A , Nababan E S M
Published: December 2022

Amorphophallus gigas is one of Sumatra's endemic Amorphophallus species that is protected in Indonesia. Amorphophallus gigas is one type of Amorphophallus with the highest flowers in the world. The conversion of land to other uses is one of the causes of the reduced population of Amorphophallus gigas. One of the natural habitats of Amorphophallus gigas was found in the Sabungan Village and Langga Payung Village, North Sumatra. The purpose of this study was to determine the distribution of the generative phase of Amorphophallus gigas in the Sabungan Village and Langga Payung Village, to determine the types of plants found around the place of growth and to determine the morphology of the generative phase of Amorphophallus. The method used in this research is the roaming method and then records the coordinates of the generative phase of Amorphophallus, records the types of pollinating insects around it and observes the morphology of Amorphophallus gigas. The results showed that there were 11 individuals in the generative phase of Amorphophallus gigas in the Sabungan Village and Langga Payung Village, where 10 individuals grew on rubber land cover and 1 individual grew on oil palm land cover. A total of 2 individuals were found in bud condition, 1 individual was in bloom, 2 individuals were wilted and 6 individuals were found at the seed formation stage. There are 12 types of insects found around the generative phase of the Amorphophallus.
Phylogenetic reconstruction of tree species on the University of North Sumatra Campus, based on the rbcL gene
Authors: Rangkuti A B , Mawarni A , rangkuti R R
Published: December 2022

A phylogenetic tree is an arrangement that can describe kinship data in the form of a branched tree. In the field of forestry, identification using morphological data is difficult because it takes a long time and the fruit and flower seasons are uncertain. Another alternative that can be used to create a phylogenetic tree is to use secondary data. This study aims to explore the availability of GeneBank sequence data for tree species at the Universitas Sumatera Utara and create a phylogenetic tree to see their relationships based on rbcL markers. The results showed that the highest sequence of trees on the USU campus using the rbcL gene was 86.8%. In the reconstruction of the phylogeny tree, the boostrap value is above 70%, and tree species are grouped according to the same family.