bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of agroforestry oil palm for peatland restoration in Jambi Province: establishing process and initial results
Authors: Sundawati L , Pamoengkas P , Siregar I Z , Mardhatillah M , Rangkuti AB , Hartoyo A P P , Fadillah A 
Published: April 2020

Abstract
Rapid degradation of peatland forest in Indonesia is caused by conversion into plantation forest and agriculture land, including oil palm plantation by farmers. Restoration of peatland is then needed with involvement of local farmers as main stakeholder. This paper presents establishment process and initial result from an action research on peatland restoration using biodiversity enrichment experiment in existing oil palm smallholder plantation to develop oil palm agroforestry. The experiment was established in Sinar Wajo Village, Tanjung Jabung Timur Regency, Jambi Province in which 30 plots in sizes of 25m2, 100 m2, and 400 m2 placed systematically over about 21 ha oil palm plantation belong to a group of farmers. There were 1,180 trees of 6 species, i.e. blangeran (Shorea blangeran), pinang (Areca pinanga), petai (Parkia speciosa), durian (Durio zibethinus), jengkol (Archidendron pauciflorum), and kopi liberika (Coffea liberica) with 0, 3, and 6 diversity levels, created tree island on the sea of oil palms. Approach to local leaders was very important for the initiation of the action research. Focus group discussion with farmer group, provision of seedlings and labour wages were conducted to ensure farmer willingness of participation. Capacity building, such as training on tree cultivation, bio-fertilizer production and study tour was conducted as incentive for farmers. The initial result of plant growth measurement from experiment plots showed 21 months after planting many planted trees grew well. Blangeran as native species of peatland forest showed the best growth performance. Pinang, Kopi Liberika and Durian were also showed relatively good growth performance. Only Petai and Jengkol showed less growth performance. High farmer participation on the establishment of oil palm agroforestry as peatland restoration model was mostly driven by provision of incentives. Oil palm agroforestry is a promising model for restoration of already planted by oil palm peatland area, and involving farmers is important factor for the success of peatland restoration through appropriate social approaches.
Telajakan and mixed gardens landscape as household based agroforestry supports environmental aesthetics and religious ceremonies in Bali
Authors: Purba J H , Manik I W Y , Sasmita N , Komara L L 
Published: April 2020

Abstract

Telajakan and mixed gardens are land management systems in Bali. The existing plants are a combination of tree plants, shrubs, palms, bamboo and others by combining agricultural crops and or livestock. This practice is found in one land management unit to the landscape of rural agroecosystems. In the agroforestry system, this system is more of a family-based activity (household-based agroforestry). This study discusses and examines the value of plant species, as well as the benefits for the household level in Tabanan Bali. The study was conducted from January to June 2019 in Pinge Village, Tabanan Regency, Bali, which is a village that provides green space and the beauty of environmental aesthetics. Observation of various species of plants was carried out using Quick Biodiversity Survey (QBS) method, the complementary of the Rapid Agro Biodiversity Appraisal (RABA) method. The observations were carried out on 40 plots representing agroforestry land-use systems. The results showed that the biodiversity and species richness level belonged to the medium category. There are 55 plant species from a combination of agricultural and forest plants. The vegetation structure of Telajakan and mixed gardens guarantees a natural regeneration process. Telajakan and mixed gardens cause the development of commercial species with high economic value and fast-growing species. The plants used by the community for aesthetics, religious ceremonies, food, medicines, building materials, and household utensils. Most of the purposes of use are for green open spaces and environmental aesthetics, subsistence consumption. The results of other plants that are useful for commercial purposes are special crops that are cultivated intensively. The community believes that by observing the environment and the aesthetics of nature is the realization of worship in the relationship between humans, nature and God (Tri Hita Karana).
Geochemistry features of sediments of small urban arctic Lake Komsomolskoye, Murmansk region
Authors: Slukovskii Z. I. , Dauvalter V.A. , Denisov D.B. , Siroezhko E.V. , Cherepanov A.A. 
Published: April 2020

Abstract
First data of geochemistry and mineralogy of recent sediments of small Lake Komsomolskoye located in Monchegorsk town from Murmansk region (Russia) are presented. The high concentrations of heavy metals were found in surface layers of researched lake sediments. The most accumulation level is initialled for copper and nickel, which are entered to lake from copper-nickel plant complex situated near the arctic town. Other metals also can enter to waterbody in result of activity of this factory complex. In addition, lead, cadmium, antimony, thallium and other elements may be products of the atmospheric transport of pollutants from industries of North and East Europe. Moreover, we have studied main fractions of heavy metals from upper layers of Lake Komsomolskoye and morphology and composition of technogenic particles of nickel, copper, iron and other metals. The origin of these particles is directly associated with the different stages of processing technology of nickel and copper ore on the copper-nickel plant complex (crushing, flotation, roasting, and smelting).
Spacing optimization of horizontal wells in Pu 34 tight oil reservoir of Daqing oilfield
Authors: Liu Lifeng , Ran Qiquan , Kong Jinping , Wang Xin 
Published: April 2020

Abstract
The geological conditions of Fuyu tight reservoirs in Pu34 well area of Daqing Oilfield are complex. The drainage area of horizontal wells with hydraulic fracturing under different well distribution methods is not clear, and the reasonable well spacing is difficult to determine. Based on the study of the geological characteristics and engineering parameters of the Pu34 well area, this paper establishes the multi-medium geological models of different scales for fluvial sediments in Fuyu reservoir, and studied the reasonable well spacing under different well distribution modes by numerical simulation. The results shown that the development effect of well distribution along the channel direction is better than that along the cutting channel direction. The optimum well spacing along the channel direction is 1800m, and the optimum well spacing along the cutting channel direction is 500m. This research provides a basis for the arrangement of horizontal wells in Fuyu tight oil reservoirs of Daqing Oilfield.
The basic principle of enhancing oil recovery technology in heavy oil reservoirs
Authors: Sun Jianghe , Zhang Fusheng , Li Xuening , Shan Dalong , Liu Guoliang , Zhu Zhuoyan 
Published: April 2020

Abstract
Due to the heterogeneity of heavy oil reservoirs and the high viscosity of heavy oil, the recovery rate of heavy oil reservoirs is much lower than that of conventional reservoirs. So increasing the recovery rate of heavy oil reservoirs is of great significance to the goal of improving the technical level of heavy oil development proposed by the National Energy Plan. This paper outlines several commonly used techniques for improving the recovery of heavy oil reservoirs, including steam flooding, hot water flooding, polymer flooding, surfactant flooding, microbial flooding, foam flooding, ultrasonic viscosity reduction technology, etc. And briefly explains the basic principles. The internal causes of the problem are analyzed, and several focal points for improving the recovery of heavy oil that should be paid attention to are put forward.
Numerical simulation model adaptability research for fractured reservoir
Authors: Xie Kun , Li Fangfang , Li Depeng , Zhang Qiang , Chen Xueli 
Published: April 2020

Abstract
Characterization and forecasting in fractured reservoirs is one of the most challenging topics in oil and gas industry. Due to significant difference of fluid flow mechanism in fracture and in matrix, managing such reservoirs requires construction of representative reservoir models. Dual porosity & dual permeability model (DPDP) is the first choice of fractured reservoirs, but history matching and plan prediction of this model facing poor convergence and long running time. Other models like dual porosity & single permeability model (DPSP), single porosity & single permeability model (SPSP) sometimes can replace DPDP and can be able to improve convergence and save calculation time, but lack of model equivalence criterion. In this study, 84 cases of 4 reservoir models has been built and simulated to study the equivalence criterion. Permeability difference and oil viscosity are considered to be the main influencing factors affecting model equivalence. With the application of the equivalence criterion, weak convergence and time consuming of fractured reservoir simulation can be improved.
Influence of water resources in Xinjiang on exploitation of coal resources and measures for their use
Authors: Cheng Chunyan , Zhang Yan , Yan Qiang , Zhou Fengying , Gao Tianming , Hou Baojun , Zhang Songtao , Song Mei , Wang Qingwei 
Published: April 2020

Abstract
Xinjiang is rich in coal resources, but the extremely shortage of water resource in some regions has significant impact on coal exploitation. Water is required in coal exploitation, as well as cleaning, utilization and upgrading of coal, so the shortage of water resource is impacting the fate of coal directly. Xinjiang area is the 14th coal base of our country, a foothold of the strategy of West-Development in China, and a support point of national strategic layout of the Belt and Road Initiative. If the problem of coal and water is solved, the problem of energy safety and nationality will be solved. Based on the comprehensive analysis of coal geological conditions and water resources conditions in Xinjiang, we have studied the spatial distribution relationship between coal resources and water resources in this paper, and find that the whole water resource is short in regions of Xinjiang with rich coal resource. In this paper, some feasible suggestions have been put forward to solve the problem of asymmetric distribution of water and coal resources as the key problem at present, in order to provide reference for departments of resource development and planning.
Design of backstepping controller for T-type network inverter
Authors: Gao Guanghui , Zeng Jiaqi , Han Jianding , Lei Xiaoben 
Published: April 2020

Abstract
In the process of power conversion of new energy generation, complex two-stage converter is needed. T-type network inverter is a kind of transformer that can realize three-phase power output from two single-phase output inverters. Functional Topology, the purpose of this paper is to design the circuit topology and controller so that the inverter output voltage meets the power supply requirements. First, the DC power input circuit and transformer structure are designed according to the principle of voltage vector synthesis. Then the controller is designed by state space average modeling method and backstep method. Finally, the system model is built by Matlab/Simulink simulation software. The conversion of 27V DC power to 220V / 50Hz three-phase power for market power supply verified The effectiveness of The design content of this paper.
Impacts of electrode structure on plasma discharge in pre-breakdown period for water environment treatment
Authors: Huang Yan , Zeng Xinwu 
Published: April 2020

Abstract
Since the liquid discharge problem has been incorporated into the line of sight, many scholars have done a lot of research on it. In this paper, experiments on the pre-breakdown period in underwater plasma discharge were carried out. Among the parameters of underwater plasma discharge, the electrode structure is firstly taken account by virtue of its intuitive, easy-to-process, and diversity. With the refinement of the application of liquid discharge in liquid-electric processing, research on the effect of electrode structure on underwater plasma discharge is deepening. In this paper, two sets of electrode groups were proposed in a pioneering manner through the theoretical analysis and precise control of the experimental parameters. Based on the experimental results, rigorous and reliable analysis and summary were demonstrated. The conclusions of this paper would be helpful for water environmental treatment.
Denitration performance of CuO/γ-Al2O3catalysts modified by CeO2
Authors: Zhang Qilong , Dong Yong , Cui Lin , Zhang Liqiang , Wang Peng 
Published: April 2020

AbstractCuO-CeO2/γ-Al2O3catalysts with different CeO2loadings were synthesized by wet impregnation method. Selective catalytic reduction (SCR) of NO over the two kinds of catalysts was carried out in a fixed bed reactor. CuO-CeO2/γ-Al2O3catalysts reached NO conversion efficiency 65% at 150 °C and maintained over 80% at 200-400 °C, The maximum efficiency is stably reached at 300 °C. CuO-CeO2/γ-Al2O3catalysts showed wider temperature range than that of the CuO/γ-Al2O3. NH3-TPD tests were carried out to study the adsorption and oxidation behavior of NH3over CuO-CeO2/γ-Al2O3catalysts with different CeO2loadings in the presence of oxygen. The NH3adsorption and activation performance were modified attributing to the modification of the Surface acidity of the CuO-CeO2/γ-Al2O3catalysts. The mass transfer was improved due to the promotion of the pore numbers in 8-50, 50-200μm which was another NO conversion promotion factor. Surface acidity and the pore volume decreased obviously as CeO2overloaded in CuO-CeO2/γ-Al2O3, with a negative influence of NH3adsorption and oxidation performance. It is considered to be the main factor of the NO conversion efficiency decreased.
Radioactivity measurement in glacier and Polar ice-caps: An overview
Authors: Ayoub Anuor. A.T , Song Yushou 
Published: April 2020

Abstract
Glacier is an extended mass of ice formed by snow falling and accumulating over the years and moving very slowly either by descending from high mountains, as in valley glaciers or by moving out of accumulation centers, as in glaciers on the continent. Glaciers are a significant source of potable water and plant irrigation, any contamination of this significant source in glaciers due to radionuclides may affect freshwater supplies and livelihoods. It is well known that exposure to ionizing radiation could lead to health hazards and harm to the environment. Therefore, awareness of the distribution and concentrations of natural and artificial radionuclides in the glacier region is crucial, and that is why it provides and clarifies helpful information about radionuclide pollution in the environment. This evaluation gives insights into the overview of the radioactivity of natural and artificial radionuclides in the glacier region (Arctic and Antarctica). These information are crucial for predicting the effects of radionuclide distribution and transport in ecosystems, and can also be an indication of the effects of external human activities in the cold regions.
The Radiation properties of Barite-xylem shielding board
Authors: Chen Tzong-Jer 
Published: April 2020

Abstract
Radiation is used in a variety of medical and scientific fields but poses potential danger to the human body. Hospital medical x-ray technicians traditionally use lead shielding materials to absorb radiation. However, lead has environmental disadvantages, with high toxicity to humans. Barite, a heavy-weight material, is added into concrete and bonded with xylem fiber, forming a shielding board as a replacement for lead. The xylem fiber barite shielding board (XFBSB) development and shielding properties are investigated in this report. XFBSB is designed for diagnostic medical x-ray shielding. It may be applied as shielding in walls and ceilings, doors and movable wall partitions. The physical properties of XFBSB are 14 mm in thickness with density ⩾ 2.0 g/cm3. This board was irradiated using a standard x-ray tube (Type MXR 320/Comet Y. TU 320 G03, TÜV NORD Sys Tec GmbH & Co. KG, German) with 70 kV, 100 kV and 150 kV Voltages respectively. The current of this standard x-ray tube is 22.5 mA, respectively. From the measured ambient dose equivalent H*(10), the attenuation factor F=H*(10) with board/H*(10) without board was calculated. For comparison, lead boards of 1, 2, 3, 4 and 6 mm thicknesses were irradiated under equal conditions with the attenuation factors F fitted for the different lead board thicknesses. The boards are proven to ⩾ 1mm lead equivalent in all irradiation energies. The XFBSB can substitute for lead shielding for photon energies around diagnostic medical areas. This board provides adequate shielding, is non-toxic, fire proof, easily installed and low cost.
Simulation and experiment of NOX concentration detection in diesel engine exhaust gas
Authors: Liu Xiaonan , Guo Ao , He Yanbo , Mu Yanlong , Yang Xiaotao 
Published: April 2020

Abstract
As people pay more attention to environmental problem, the issue of how to measure and reduce pollutant of the exhaust of ships were put on the agenda. To realize the detection of NOX(nitrogen oxides) content in the marine diesel exhaust emissions, the SIMULINK of MATLAB software with superior data processing capabilities was selected in this paper to enable the detection of NOX content by direct absorption measurement based on laser absorption spectroscopy (TDLAS).). The absolute error of the simulation model was less than 0.15%, and the maximum relative error didn’t exceed 1.25%. At the same time, the simulation error of the model was less than 5.0% compared with the test results of the AVL emission meter. The results had shown that the model can accurately simulate the detection process of nitrogen oxides of diesel exhaust emissions. It not only provides reference data onto people to detect harmful gases in ships but also provides valuable experience in optimizing diesel engines control strategies.
The distribution of combustible ice and the status of exploitation
Authors: Wang Ruihe , Guo Lei 
Published: April 2020

Abstract
The distribution of combustible ice in the world is investigated. The characteristics of different mining methods are clearly defined by the analysis of the successful cases of the development of combustible ice in the United States, Japan, Russia, Canada and India. The distribution rules and the historical process of the development of the combustible ice in China are introduced, the discovery of the combustible ice in the South China sea is analyzed. The analysis of ice production technology, the mining methods, applicable reservoirs and existing problems of combustible ice are expounded. The significance of combustible ice as a new energy to alleviate energy crisis is pointed out.
Mathematical modelling and operation parameters analysis of proton exchange membrane fuel cell
Authors: Zhu Lingkun , Yu Qiang , Huang Ying , Guan Jingyu , Wang Yupeng , Yan Yanfei 
Published: April 2020

Abstract
The fuel cell is a device which can convert chemical energy from fuel into electrical and thermal energy directly. It has advantages like high power density, fast start-up and high conversion efficiency. Its prospects of application in transportation, fixed power supply and standby power generation are great. Fuel cell is a dynamic complex system with multi-phase, multi-scale and multi-physical fields. Based on the working mechanism of fuel cell, this paper establishes a mathematical model to simulate the electrochemical reaction, material and energy transfer process in fuel cell. The parameters such as temperature, pressure, concentration, current and potential, which are difficult to measure, are visualized to deepen the transfer and counter-reaction in fuel cell. In order to provide important scientific basis for the optimal design and system control of the stack, the mechanism should be understood and the optimum reaction conditions should be found.
Optimization modelling of HCMC-STATCOMs for offshore wind power based on PSCAD
Authors: Dou Fei , Wang Weiyuan , Xia Kai , Yu Xuan , Wang Lijun , Xu Yiqing 
Published: April 2020

Abstract
Under normal circumstances, the voltage fluctuation of the wind farm’s grid connection point is mainly caused by the volatility of wind power output. In recent years, with the clustering development of offshore wind power, the voltage fluctuation brought by the output fluctuation of wind power is becoming more and more notable. The main method of improving the reactive voltage problem of wind farms is to add more static and dynamic reactive power compensation devices. Hybrid cascaded multilevel converter STATCOMs (HCMC-STATCOMs) don’t need transformers to increase the device capacity and decrease the harmonics on the output voltage, which is effective in reducing the device cost and volume. This paper firstly introduces the topology and operation principles of an HCMC-STATCOM and then carries out a comparative study on HCMC-STATCOMs and traditional cascaded STATCOMs. Finally PSCAD/EMTDC is applied to model and simulate HCMC-STATCOMs. The simulation result shows that the reactive power of HCMC-STATCOMs can accurately vary according to the system’s demand on reactive power. This means that HCMC-STATCOMs have good dynamic performance and the harmonic contents in the output phase voltage and AC current are quite small. As a dynamic reactive power compensation device, HCMC-STATCOM can be adjusted in real time according to the system’s reactive power requirements, and has the advantages of small volume and low cost. The simulation results show that the properties of HCMC-STATCOMs are advantageous for the operation and control of the system and applicable for the dynamic reactive power configuration of offshore wind power.
Vessel hydrostatic test duration analysis in prssurized water reactor nuclear power plant overhaul
Authors: Zhang Zhenguo 
Published: April 2020

Abstract
The vessel hydrostatic test is one of the important test means of the nuclear vessel sealing and pressure resistance, and it is an important project in the plant overhaul. Because the vessel hydrostatic test involves many key systems and key vessels, and it belongs to the critical path or time critical path in plant overhaul, how to estimate the vessel hydrostatic test duration in overhaul is necessary. This paper discusses the actual hydrostatic test time of different vessels in pressurized water reactor nuclear power plant overhaul, and divides the test time into three categories, that is long (more than 6 days), medium (3 to 6 days), and short time duration for a project (less than 3 days). This paper also discusses the key factors that influence the vessel hydrostatic test duration and puts forward the optimization suggestions of vessel hydrostatic test duration.
Natural circulation systems in nuclear reactors: advantages and challenges
Authors: Ahmed Nisrene M. , Gao Puzhen , Bello Solomon 
Published: April 2020

Abstract
Following the Fukushima disaster in Japan in March 2011, a number of questions and doubts about the safety of nuclear reactors have been raised globally and many nations have begun revising and improving the nuclear installations. Natural circulation plays a major role in nuclear accident. This significance of the natural circulation-based systems led us to study the natural circulation phenomena for better understanding and in order to ensure the safety and efficiency of natural circulation systems. This review focuses on the advantages and challenges of natural circulation systems.