bluuebunny/crossref_metadata_2025 huggingface dataset:
Behaviour of the conductivity in metallic 70 Ge:Ga close to the metal-insulator transition
Authors: Errai Mohamed , Amrane Said
Published: January 2021

The electrical transport properties in sample 1 of impurity concentration n=xx of the 70Ge: Ga system are studied in the absence of a magnetic field and at low temperature in the range 0.53 to 0.017 K. It is noted that the electrical conductivity of sample 1 exhibits a metallic behavior. We found that the exponent S is equal to 0.5 (σ=σ(T=0)+mTs). This result is in agreement with the theory of weak localization (WL) at 3D and the theory of electronelectron interactions (EEI). We also found that sample 1 is located near the metal-insulator transition (MIT) of the metallic side.
Field Oriented Control of Doubly Fed Induction Motor using Speed Sliding Mode Controller
Authors: Mahfoud Said , Derouich Aziz , El Ouanjli Najib , Mohammed Taoussi , Hanafi Ahmed
Published: January 2021

This article presents a modeling and control of the Doubly Fed Induction Motor (DFIM), associated with two inverters controlled through the Pulse Width Modulation technique (PWM), the control of the DFIM is carried out by the approach of Rotor Flux Oriented Control (RFOC) according to the direct axis. In this approach, regulation is done by classic PI regulators, the latter having undesirable overruns and static errors in non-linear systems, for that the introduction of the control by sliding mode in place of the classic PI speed regulator, that is in the form of a control law based on this type of controller since it is invariant to the non-linearity of the system and precise, stable, simple and has a good response time, in order to validate the objectives of improving the DFIM behavior in front of the reference parameters, such as the speed and the torque imposed on the machine. The results of the proposed approach are validated by its implementation on the Matlab/Simulink environment.
Farmer Perceptions and Preferences to Shallot Farming Technology Introduction in Grobogan District, Central Java, Indonesia
Authors: Sahara Dewi , Citra Kusumasari Aryana , Hermawan Agus
Published: January 2021

Farmers commonly use seed bulbs in shallot farming. Therefore it is required to conduct a demonstration plot to promote the technology of true shallot sheet (TSS). The study aims to determine the performance of the newly seedling technique and determine the perceptions and preferences of farmers towards shallot farming, in Padang Village, Tanggungharjo Sub- District, Grobogan District, in September - November 2018. The study used a demonstration plot of shallot farming using seedling and survey methods to the 30 shallots farmers. Financial analysis (BCR and MBCR) was used to determine the performance of shallot farming, while farmers' perceptions and preferences were analyzed descriptively with scoring techniques. The results showed that even though the cost of shallot farming using seedling was higher, it resulted in higher production (BCR 2.76 vs 0.25). The TSS using as planting material against bulbs was also beneficial since the MBCR value was 5.64, implying that the seedling technique was more profitable than seed bulbs using. With these significant results, farmers stated a high perception of shallot farming using seedling, indicated a high level of preference, which is 73.33 - 93.33%. Based on these results, the government should widely disseminate the TSS to shallot farmers.
The Effect of Land use and Subsidized Fertilizer for Rice Production Case Study: Tangerang District, Banten
Authors: Mulyaqin Tian , Kusumawati Septi , Winanti Nita , Kardiyono
Published: January 2021

Tangerang District is one of the rice producers in Banten Province. The intensification of rice production is one of the solutions due to the agricultural land conversion problem in Tangerang. The purpose of this study is to analyze the farmer perception about subsidized fertilizer and we also analyze the effect of land use and subsidized fertilizer for rice production at the farmer level in Tangerang. The data used in this study were collected through an interview survey using a structured questioner to 35 respondents in Tangerang in 2016. The data were analyzed using descriptive and quantitative analysis. The result showed that the farmers perceive that the availability of subsidized fertilizer is frequently rare especially for nitrogen fertilizer and phosphorus fertilizer. The study also shows the rice production at the farmer level was affected by land use, the application of subsidized urea fertilizer, the application of organic fertilizer, and the application of returning the straw to the paddy field. All of these significant factors on rice production were inelastic in the short term and long term. It is important to decrease agricultural land conversion and returning the straw to the paddy field to maintaining rice production in Tangerang.
Improving the supply of forage and staple food of smallholder farmers in therural marginal dry land of East Nusa Tenggara, Indonesia
Authors: Kana Hau Debora , Nulik Jacob
Published: January 2021

Cattle and corn are important for small farmers in west Timor.

However, owing to the lack of proper technologies, marginal lands and erratic rainfalls, productivity of both are low. To improve the productivity, a conservation agriculture approach was demonstrated during 2017-2019 at Camplong II village, on a marginal land with shallow top soil, rocky formation, with existing corn production of <1 ton/ha. The technology package in 2019, includes: (i) hedges of Leucaena leucocephala (planted at 2 m within the row and 4 m between the rows), (ii) Deep planting hole (40 cm x 40 cm x 40 cm) filled with mixtures of soil and cattle manure, (iii) planting of grass within the rows of Leucaena, (iv) cover crop legumes: cow pea, Clitoria ternatea, and Mucuna holtonii while using corn stover and cattle refusals as mulches. Forage was obtained from Leucaena and the grass, while herbaceous legumes were left uncut. The results include: (i) year round supply of high quality forage, (ii) improved the daily weight gain of fattening cattle (0.2 to 0.3 - 0.6 kg/head/day), (iii) reduced calves mortality down to 0%, (iv) and increased corn yield to 5 ton/ha and a second crop harvest as green corn.
Analysis of Peanut Farming in The 3rd Planting Season in Pemalang Ditrict, Indonesia
Authors: Dyah Arianti Forita , Nurwahyuni Endah , Minarsih Sri , Faizal Amri Aldicky
Published: January 2021

Peanuts are regarded as the second most important commodity after soybeans which have quite high economic value. Its production tends to decrease every year due to the reduction in planting areas. Meanwhile, the rainfed paddy fields land in Central Java is quite potential, thus its utilization can be used as an alternative to developing peanut. Accordingly, this study aims to find out the level of income and feasibility of peanut farming in Tegalsari Barat, Ampelgading Subdistrict, Pemalang District, Indonesia. The sampling was performed using purposive random sampling method with a total of 22 people. The level of profit could be found by using the return cost ratio (R/C ratio). The results indicated that during one planting season, the average cost was IDR 12,647,000 ha-1. The average production of peanut was 4,600 kg ha-1 wet pods with a selling price at farm level of IDR 8,500, so the average revenue was IDR 39,100,000 ha-1.

The analysis of R/C feasibility showing the value of 3.09 (R/C > 1) indicates that peanut farming in the 3rd Planting Season (PS-3) in Pemalang District is feasible to be cultivated.
The Effect of Trade Policy on The Position of Indonesian Coffee Market among The Major Importing Countries
Authors: Fortunika Sevi Oktafiana , Harianto  , Suharno
Published: January 2021

Indonesia is the largest coffee producer in the world after Brazil, Vietnam and Colombia, but it was confronted with market problems. This paper, therefore, analysed the demand system as the position market for Indonesian coffee, either green bean or roasted coffee in the main importing countries such as Germany, Japan and The United States. The linear Approximate Almost Ideal Demand System (LA/AIDS) model was used to analyse the position of Indonesian coffee and its competitors. Time series data from 1996 to 2017 were obtained for the analysis. Empirical results indicated that most of the slope coefficients were statistically significant and in accordance with microeconomic theory. The variables of trade policy effected the Indonesian coffee trade. Indonesian green bean was found to be elastic in Germany, Japan, and The United States. Then, Indonesian roasted coffee was found to be inelastic in Japan. Indonesian green bean was a luxury good only in Germany, but Indonesian roasted coffee was an inferior good in Germany and The United States. Both Indonesian green bean and roasted coffee were a necessity in Japan. Almost Indonesian coffee substitute for Brazilian coffee and Colombian coffee, and complementary with Vietnamese coffee as its competitor.
The Causal Agent of Fusarium Disease Infested Shallots in Java Islands of Indonesia
Authors: Herlina Lina , Istiaji Bonjok , Wiyono Suryo
Published: January 2021

The success of disease control is largely determined by the validity of information about the type of causal-pathogen. Fusarium oxysporum f. sp. cepae (FOC) was reported to attack shallots and cause leaf twisting disease in Indonesia. We have conducted researches to investigate the causal agent of Fusarium disease and carried out growth tests on nine genotypes of shallots to determine the disease severity and disease indexes, and the correlation between diseases several agronomic traits. Thirty-five strains of Fusarium spp were isolated from wilted shallots tree and bulbs. Based on morphological characterization and rapid test to the isolates, they were identified as F oxysporum, F verticillioides, F solani and F proliferatum. The shallot genotypes that showed a tolerant response to FOC isolates tested were only Sumenep variety. Mentes, Tajuk, Batu Ijo, and Bima Brebes varieties show susceptible response.
Corn-seed Technology: A Study of a New Technology Introduce to Farmer Using Importance Performance Analysis
Authors: Oelviani Renie , Sahara Dewi , Praptana R Heru
Published: January 2021

The effort to increase hybrid maize in Indonesia is one of the government's crucial programs. Given that multinational companies still master hybrid corn seed technology, farmers need to become independent seed producers with the introduction of technology. Despite the difficulty level of technology, capital and resources are limited. The study aims to analyze the effectiveness of hybrid corn seed technology using the Importance Performance Analysis (IPA) approach in the demonstration plot of maize nurseries in Kendal Regency in 2018-2019. We surveyed at the end of 2019 activities to 33 farmers and 12 assisting officers. The result of this research is the level of interest suitability and technology performance of hybrid corn seeds of 82.61 percent. The average competent value of interest is 4.39, and the performance value is 3.63. Three attributes that have a high level of significance, but whose performance is not yet optimal are rouging, detasselling, and machine seed processing. In the future, evaluate the three attributes as an effort to produce quality hybrid maize seeds at the farmer level on a large scale that can be activated.
Trass Effect as a Source of Silicon on Soil, Hay, Husk and Growth of Rice Plants
Authors: Amin Mirawanty , Adi Prasetyo Rahadian , Padang Chandra
Published: January 2021

Silicon (Si) is one of the important things for rice growth. The importance of Si relates to increased rice yield, increased resistance to disease and resistance to falling. The rice is an accumulator plant of Si which requires Si for its growth. However, the Si in soil is continually decreased therefore the additional Si is needed intothe soil. Trass is one of the natural materials containing Ca and Si, therefore it can be used as a Si fertilizer. This study aims to determine levels of soil Si, straw, husk, and growth in rice. This research consisted of three types of soil, Oxisol, Inceptisol and Vertisol as the main plot and 7 doses of burnt fuel namely 0 (D0); 1.25 (D1); 2.5 (D2); 3.75 (D3); 5 (D4); 7.5 (D5); 10 (D6) g kg-1 of soil as subplots. The treatment which is using in this research is a combination of the two factors and repeated 3 times 63 unit experiments were obtained. The results showed the Trass significant concerning to Si in the husk and Si of the soil. Vertisol gives the highest number of panicles of 27 and Si in the straw of 12.75 mg kg-1.
The Analysis of Stone Trapping in Tire Tread for Various Road Conditions
Authors: Eugene Gow Jun Yi , Ku Pei Xuan
Published: January 2021

A tire tends to trap stones in its tread pattern when the vehicle is on a move and this might affects the tire balance due to uneven tread wear of tread portion. The study aims to simulate stone trapping performance under various tire tread patterns and road conditions as well as assessing the performance of tires with stones trapped. The stone trapping phenomena on different tire tread pattern were analyzed under dry and wet road conditions. The tire models chosen were the symmetrical tire, asymmetrical tire, and directional tire. The model of these tires, stone and a flat road surface were created using SolidWorks and Fusion360 software and the static structural simulation is performed by using finite element analysis method. Tire inflation analysis and steady state rolling analysis were conducted to evaluate three parameters: total deformation, Von-Mises stress and equivalent elastic strain of the tires. It found that all three parameters are higher when stone trapped in tire for all tread pattern types. Symmetrical tread pattern provides the least wear and tear since it has the lowest increment of maximum equivalent elastic strain in both road conditions. Stone trapping in tire grooves would impact on the lifespan of the tire.
Effect of Graphene-Oxide Addition on the Microstructure and Mechanical Properties of Two-Stage Sintered Zirconia-Toughened Alumina (ZTA) Composites
Authors: Teow Hsien Loong , Sivanesan Sivakumar , Eh Noum Se Yong , Soosai Ananthan , Muniandy Suresh
Published: January 2021

United Nations has estimated that 130 million people would suffer from osteoarthritis worldwide by 2050. This disease would require patients to undergo a surgery known as Total Hip Replacement (THR) which has a failure rate of approximately 1 % with a lifespan of 20 years. The biomaterials used to manufacture this total hip artroplasty are mainly made of Zirconia-Toughened Alumina. In this work, Zirconia Toughened Alumina (ZTA) composites with 10 vol% Y-TZP content were doped with small amount (0.01 to 1 wt%) of graphene oxide (GO). The GO-doped ZTA composites were produced via two-stage sintering with T1 ranging between 1400°C and 1550°C, heating rate of 20°C/min, followed by T2 of 1350°C and 12 hours holding time. The sintered ZTA samples were then evaluated on its microstructure and mechanical properties such as bulk density, Vickers hardness, Young’s modulus and fracture toughness to investigate the effect of GO addition on ZTA samples prepared via two-stage sintering. The results showed that ZTA composites containing up 0.1 wt% GO is beneficial in improving the microstructural and mechanical properties of ZTA composites prepared via two-stage sintering. The sample recorded a high hardness of up to 18.5 GPa, Young’s modulus of 406 GPa and fracture toughness of 5.8 MPam1/2 when sintered at T1 of 1450℃.
Arthroscopic Debridement and Arthrolysis for the Treatment of Advanced Kienböck's Disease: 18-Month and 5-Year Postoperative Results
Authors: Ayik Omer , Demirel Mehmet , Turgut Necmettin , Altas Okyar , Durmaz Hayati
Published: January 2021

Background Salvage procedures, such as proximal row carpectomy, limited or total wrist arthrodesis, and wrist replacement, are generally preferred to treat advanced Kienböck's disease. However, these procedures are particularly aggressive and may have unpredictable results and potentially significant complications.

Questions/Purpose This study aimed to present the short- to mid-term clinical and functional results of arthroscopic debridement and arthrolysis in the management of advanced Kienböck's disease.

Patients and Methods Fifteen patients in whom Lichtman Stages IIIA to IIIC or IV Kienböck's disease was diagnosed and treated by arthroscopic wrist debridement and arthrolysis were included in this retrospective study. The mean age was 30 years (range: 21–45). The mean follow-up period duration was 36 months (range: 18–60). The Disabilities of the Arm, Shoulder, and Hand (DASH) score, visual analog scale (VAS), wrist range of motion (ROM), and grip strength were measured preoperatively and then again at the final follow-up visit.

Results The mean DASH and VAS scores improved from 41 (range: 31–52) and 7.1 (range: 6–8) preoperatively to 13 (range: 8–21) and 2 (range: 0–3; p < 0.001) at the final follow-up visit, respectively. The mean wrist flexion and extension values increased from 32 (range: 20–60 degrees) and 56 degrees (range: 30–70 degrees; p = 0.009) preoperatively to 34 (range: 10–65 degrees; p = 0.218) and 57 degrees (range: 30–70 degrees; p = 0.296) at the final follow-up appointment, respectively, although these findings were statistically insignificant. The mean strength of the hand grip increased from 22.7 (range: 9–33) to 23.3 (range: 10–34; p = 0.372).

Conclusion Arthroscopic debridement and arthrolysis may improve wrist function and quality of life due to the preserved ROM and hand grip strength after short- to mid-term follow-up periods despite the radiographic progression of Kienböck's disease.

Level of Evidence This is a Level IV, retrospective case series study.
Improvement of Nemadectin Production by Overexpressing the Regulatory Gene nemR and Nemadectin Biosynthetic Gene Cluster in Streptomyces Cyaneogriseus
Authors: Wu Yuan-Jie , Yang Song-Bai , Zhang Zheng-Yu , Chen Shao-Xin
Published: January 2021

Nemadectin, a 16-member macrocyclic lactone antiparasitic antibiotic, is produced by Streptomyces cyaneogriseus subspecies noncyanogenus. Moxidectin, a C-23 oximate derivative of nemadectin, is widely used as a pesticide due to its broad-spectrum, highly efficient, and safe anthelmintic activity. NemR, a LAL family regulator, is encoded by nemR and is involved in nemadectin biosynthesis in S. cyaneogriseus. In this report, gene disruption and complementation experiments showed that nemR plays a positive role in the biosynthesis of nemadectin. The transcription level of nemadectin biosynthetic genes in the nemR knockout strain was significantly decreased compared with those in the wild-type strain MOX-101. However, overexpression of nemR under the control of native or strong constitutive promoters resulted in the opposite, increasing the production of nemadectin by 56.5 or 73.5%, respectively, when compared with MOX-101. In addition, the gene cluster of nemadectin biosynthesis was further cloned and overexpressed using a CRISPR method, which significantly increase nemadectin yield by 108.6% (509 mg/L) when compared with MOX-101.
Estimating computational limits on theoretical descriptions of biological cells
Authors: Netz Roland R. , Eaton William A.
Published: January 2021

Significance

This work addresses a new and important question concerning biological complexity. What is the level of biological complexity that can be theoretically described in molecular detail? Simple algebraic equations are presented that determine the computational time required to simulate simplified molecular models for a single cell, the genetically simplest bacterium, and the most important and interesting multicellular system, the human brain. The results place limits on when, if ever, such theoretical descriptions will be possible.
Relaxed tarantula skeletal muscle has two ATP energy-saving mechanisms
Authors: Ma Weikang , Duno-Miranda Sebastian , Irving Thomas , Craig Roger , Padrón Raúl
Published: January 2021

Myosin molecules in the relaxed thick filaments of striated muscle have a helical arrangement in which the heads of each molecule interact with each other, forming the interacting-heads motif (IHM). In relaxed mammalian skeletal muscle, this helical ordering occurs only at temperatures >20°C and is disrupted when temperature is decreased. Recent x-ray diffraction studies of live tarantula skeletal muscle have suggested that the two myosin heads of the IHM (blocked heads [BHs] and free heads [FHs]) have very different roles and dynamics during contraction. Here, we explore temperature-induced changes in the BHs and FHs in relaxed tarantula skeletal muscle. We find a change with decreasing temperature that is similar to that in mammals, while increasing temperature induces a different behavior in the heads. At 22.5°C, the BHs and FHs containing ADP.Pi are fully helically organized, but they become progressively disordered as temperature is lowered or raised. Our interpretation suggests that at low temperature, while the BHs remain ordered the FHs become disordered due to transition of the heads to a straight conformation containing Mg.ATP. Above 27.5°C, the nucleotide remains as ADP.Pi, but while BHs remain ordered, half of the FHs become progressively disordered, released semipermanently at a midway distance to the thin filaments while the remaining FHs are docked as swaying heads. We propose a thermosensing mechanism for tarantula skeletal muscle to explain these changes. Our results suggest that tarantula skeletal muscle thick filaments, in addition to having a superrelaxation–based ATP energy-saving mechanism in the range of 8.5–40°C, also exhibit energy saving at lower temperatures (<22.5°C), similar to the proposed refractory state in mammals.
Support for Nationalization and State Building in the Early American Republic
Authors: Zug Charles U.
Published: January 2021

House deliberations over healthcare legislation in 1798 show members of the Fifth US Congress debating the constitutional basis of small government assumptions about states’ rights and federal power, asking why the regime’s principles should not be understood as requiring direct federal intervention in the lives of socially and economically vulnerable groups irrespective of states’ authority. Extending the current scholarly debate over nationalization and state building in early American thought, I suggest that questions alleged by many scholars to have been excluded from political and constitutional debate in the early republic were, in cases like this, robustly contested.
Trend Analysis of Hybrid Small-hydro Generation Systems in Rural Areas
Authors: Ping Qing , Ting Ni , Liu Shi , Meilin Ye
Published: January 2021

The hybrid power generation technology of small hydropower and wind or solar energy is one of the trends of small hydropower technology transfer, which can effectively improve the quality of power generation and enhance the permeability of renewable energy. This paper proposes a document mining system, which uses Citespace to visually analyse the keywords of small hydropower, and selects the small hydropower hybrid power generation system to occupy an important position in the current power generation technology. Secondly, using the same method to construct the keyword network diagram of small-scale hydro-wind complementary power generation technology and small-scale hydroelectric hybrid power generation technology, it is found that these two kinds of technologies are the focus of research in recent years, and they are still in the stage of fierce competition, it is hoped that more in-depth research can be carried out through a variety of clustering methods.
Characteristic and Utilization Applicability Analysis of Fly Ash in Coal-fired Power Plant
Authors: Jin Shengxiang , Pan Haibin , Wei Guanghong , Zhao Zhihong , Quan Yongsheng , Jiang Long
Published: January 2021

A coal-fired power plant in Northwest China was selected to evaluate the way and scope of comprehensive utilization of fly ash, through the detection of various properties of fly ash, the local industrial and transportation conditions, so as to provide guidance for the comprehensive utilization of fly ash. The fly ash of the coal-fired power plant can be used for filling and soil restoration, but the soil environment monitoring and agricultural products collaborative monitoring should be strengthened; due to incomplete combustion of the boiler; the fly ash does not meet the preparation conditions of ceramsite; it can be used for making silicate products such as bricks and for road subgrade construction; it has the potential to extract carbon particles and magnetic beads, but not to extract Al2O3 and SiO2; it meets the requirements of radioactivity, and the way of use is not restricted by reflection; it can be used for the preparation of new materials such as environmental adsorption; it can be transported to Beijing, Tianjin and Hebei province carried by railway.
Research on Virtual Power Plant’s Participation in Power Market under the Background of Energy Internet in China
Authors: Su Yang , Kening Chen , Yang Wang , Yu Jiang , Yu Ding , Xuwen Liu , Qiuyang Ma
Published: January 2021

Under the background of energy internet, a large influx of market entities participates in the interaction of “source network and load storage” and becomes an important resource for system regulation through the electricity marketization. Among them, the virtual power plant involves several market participators such as the distributed generation, demand side adjustable resources, distributed energy storage. The research of the operation mechanism and market-oriented trading organization for the virtual power plant becomes a popular topic in recent years. This paper proposes a novel mechanism for virtual power plants to participate in the electricity trading market, including the trading categories and auxiliary service which can be provided by the virtual power plant.
Dispersion curves for Acoustic Multipole Sources on guided waves in Isotropic Tubular Structure Liquid Metal Sodium Filled
Authors: Zhang Li , Duan Jingwen , Sun Guohang , Wang Peimao
Published: January 2021

A new analytical method is proposed for the multi-pole sound source of the isotropic tubular structure liquid metal sodium with the symmetry principal axis parallel to the tube axis. For the first time in this paper, a new method is used to simulate the dispersion characteristics of an isotropic tubular structure filled with liquid sodium. By selecting a set of displacement potentials and a cylindrical coordinate system along the tube axis, the multipole sound field solution of the isotropic tubular structure filled with liquid sodium is derived. The sound field of the multi-pole source inside and outside the tube is studied, and the dispersion characteristics in the tube are numerically simulated. The results show that in the isotropic tubular structure in which the symmetrical main axis of the tube excited by the monopole, dipole and quadrupole sources is parallel to the tube axis, the dispersion characteristics of the filled liquid metal sodium vary with the thickness and temperature of the tube and change.
Fracture failure analysis of conductive arm spring of isolation switch in 500kV substation
Authors: Wang Jun , Liu Yungen , Chen Junjun , Huang Rong , Cao Xianhui , Feng Chao
Published: January 2021

Through macro inspection, chemical composition analysis, hardness inspection, graphite carbon inspection, metallographic inspection, the causes of spring fracture on conductive arm of isolation switch in a 500kV substation were analyzed. The results show that poor manufacturing technology and anti-corrosion technology of the spring are the main reason for its fracture. Corresponding control measures are put forward to avoid similar failures from happening again.
Research on Revenue Maximizing Dispatch Strategy for New Energy Micro-grid
Authors: Qin Liangdong , Qi Xiaoguang , Xu Tianfeng , Feng Renqing , Gao Chao
Published: January 2021

In this paper, a mathematical model for micro-grid energy management, including photovoltaic, wind power, micro gas turbine and energy storage devices, is established. On this basis, considering the impact of electricity price on user demand, this paper proposes a micro grid scheduling strategy based on revenue maximization.
Dynamic Analysis of 110 kv Double-circuit Compound High-strength Hollow Mezzanine Concrete-filled Steel Tube Pole
Authors: Xingeng Li , Dingzhou Guo , Bichuan Fu , Hongjun Liu
Published: January 2021

Combined with the simplified mechanical model of the pole-line system, the dynamic stability of 110kV hollow mezzanine concrete pole is analyzed and its dynamic equation is established. The main resonance mode in the plane is analyzed by the approximate analytical method, and the stability is determined and solved by the stability theory. The characteristics of wind-induced vibration are revealed from the perspective of nonlinear dynamics. Based on Hamilton principle, the partial differential equation of motion of the simplified dynamic analysis model of the tower column is established, and it is discretized into ordinary differential equation by Galerkin method. Finally, the critical frequency equation is established according to the method proposed by Bolotin, so as to obtain the dynamic stability region and instability region of the tower column. Based on the B-R motion criterion, the nonlinear dynamic stability of the pole-line system is studied, and the initial pretension, wind direction angle and span of the cable are selected for parameter analysis. The influence of these parameters on the nonlinear dynamic stability critical load of the hollow mezzanine concrete pole line system is investigated.
Modal analysis and influence law of a wind turbine main shaft
Authors: Wu Yu Xing , Yang Zhan Jun , Zheng Zhun Bei
Published: January 2021

A finite element model was established and modal analysis was performed on a wind turbine main shaft. By adjusting the length of the expansion sleeve, the effect of the length of the expansion sleeve on the natural frequency of the wind turbine shaft was summarized. The results show that the greater the length of the expansion sleeve, the greater the natural frequency of the wind turbine shaft.
A phase sequence error analysis and diagnosis of 110kV outline interval in a 220kV substation
Authors: Feng Chao , Chen Pei , Liu Jun , Zou Pinjing , Xie Yi , Long Yi
Published: January 2021

With the help of digital X-ray imaging technology, a phase sequence error of conducting rod of isolation switch was diagnosed. By studying the design drawing of GIS before field testing, the typical characteristics of conducting rod arrangement was mastered. It referred to us that the digital X-ray imaging technology should be widely promoted to improve detection efficiency.
Integrated Power System Planning of Multiple Resources with Natural Gas Network and Power Sources
Authors: He Ji-feng , Sang Zi-xia , Huang Jia-qi , Wang Si-cong , Yan Jiong , Fang Reng-cun
Published: January 2021

In order to promote all types of energy utilization, interaction between supply and demand as well as efficient operation, a new generation of energy systems which treats the electricity grid as the core came into being. Unlike traditional power system, the electricity network and gas network in the new generation of energy systems are closely linked through gas-fired units, and influence each other. Therefore, to ensure the safe operation of the future electricity network and natural gas network, the integrated framework for generation, electricity network and gas network expansion planning need to be carried out. Under the premise of meeting the electricity network and gas network safe operation constraints, we propose a multi-stage planning model for the combined generation, electricity network and gas network, in which investment cost and operating cost of the combined system are minimized. Combined generation, electricity network and gas network expansion planning is a large-scale, high-dimensional, non-convex and nonlinear optimization problem, which is difficult to solve. To solve this problem, we propose an incremental piecewise linear method to convert the original model into a large-scale mixed-integer linear optimization problem, allowing the use of sophisticated mathematical optimization method to quickly obtain the optimal solution.
Numerical simulation on velocity and temperature of a slotted swirl combustor
Authors: Li Haozhen , Lin Jiming , Zhang Yong
Published: January 2021

Cyclone combustion chamber has the advantages of compact structure, short flame length, good combustion stability, high combustion efficiency and low emissions of pollutants, etc. As one of the key components of the cyclone combustion chamber, the cyclone has a direct impact on the working performance of the combustion chamber. In this paper, we propose a slotted swirler and describe its structure in detail. We simulate the cold state flow field and the hot state temperature field in the combustion chamber of a cyclone with open seam using the CFD method, taking into account the effect of open seam on the air flow field and temperature distribution after the cyclone at different angles. The simulation shows that the temperature distribution in the slotted swirl combustor exhibited a center-focused flame of higher temperature, compared with the non-slotted swirler, the slotted swirler exhibits certain advantages in terms of drag reduction, combustion stability and combustion efficiency, which has a certain guiding effect on the improvement of the working performance of the combustion chamber.
Analysis of Solar and Wind Power on Access Planning of Multiple Renewable Energy Sources
Authors: Yan Jiong , Sang Zi-xia , Wang Si-cong , Du Zhi , Huang Jia-qi , Yang Dong-jun , Wang Ya-lei
Published: January 2021

The scenario generation method suitable for solar and wind power obeying any probability distribution and the concept of cluster was brought up to improve the consumption ability of distribution network of medium and high voltage for renewable energy. The planning model of renewable energy access was established based on cluster partition considering the investments and power generation interests of power producers as well as the power match degree within clusters. The Benders decomposition method was employed to solve the planning problem, and the complicated planning problem of renewable energy generation is decomposed into the decomposed investment operation model. Therefore, the access planning of renewable energy taking account of the solar and wind power was realized.
Sponge City Planning and Construction of Small Towns in Subtropical Mountainous Areas of Yunnan Province
Authors: Qiu Yan , Xu Haodong , Yang Yanqing , Zhao Yan , Wang Jing
Published: January 2021

Taking Ning’er County, a small town in a subtropical mountain area, as an example, explore a scientific and reasonable sponge city construction plan suitable for small towns. In analyzing the problems of water safety, water resources, water environment, and water ecology in the construction of Ning’er County sponge city, the sponge city construction goals were put forward according to local conditions, and the construction process of the entire process of “source reduction, regional control, and system governance”, Proposed a systematic planning and construction plan for Ning’er County sponge city construction.
Study on the relationship between erosion and deposition evolution of artificial beach and protection project
Authors: Ge Long Zai , Liu Hai Yuan , Chen Han Bao
Published: January 2021

Based on the national positioning of “Blue Bay” regulation, this paper combines the Yueliang Bay renovation project of Rizhao Port, and uses the theory of parabola type headland balanced shoreline to propose the scale relationship between artificial beach and protection scheme. Through the test and verification of large scale normal physical model, the beach stability scheme and maintenance period are given, which meet the design requirements. The results can provide technology for similar projects Operation guidance.
A research for the safety influence of dropping anchor on the submarine pipeline
Authors: Hu Ke , Zhang Ci-heng , Zhou Rui-zhe , Gao Feng
Published: January 2021

The oil submarine pipeline would transfer the gas from the oil well offshore to the land. Considering the wharf may be located nearby area and the pipeline would pass through under the ship channel. There would be danger to the pipeline when the dropping anchor at the emergency situation. In this research, the process of the anchor dropping is introduced. Firstly, the speed of the anchor was obtained by experimental method when the anchor falling to the seabed above the pipeline. Meanwhile, the maximum impact force of the dropping anchor at different protective layer situation was also tested. This research would be instructive to the design of pipeline protection.
Application of GWLF model in the Baohe River Watershed: Analysis of the source composition of nitrogen and phosphorus in the region
Authors: Qi Zuoda , Kang Gelin , Hu Chuanqi , Xu Yanan , Chen Hanbao
Published: January 2021

The Luan River is one of the main rivers entering the Bohai Sea, and the Baohe River is a major tributary of the Luan River. Determining the contribution of pollution sources in the watershed where the upstream river enters the sea is a prerequisite for formulating environmental management measures in the sea area. Facts have proved that the model is an effective tool to determine the main environmental targets, especially in the analysis of pollution sources in the watershed. This paper uses the General Watershed Load Function (GWLF) model to simulate the monthly streamflow, dissolved nitrogen (DisN) load and dissolved phosphorus (DisP) load in the Baohe River Watershed from 2006 to 2014, and the contribution ratio of each pollution source in the source allocation of nitrogen and phosphorus load is emphasized. The application of the model shows the effectiveness of planning nitrogen and phosphorus management strategies for decision-makers, and provides a certain decision-making reference for pollution control in the watershed into the sea.
A target tracking algorithm based on ship exhaust
Authors: Deng Mengtao , Peng Shitao , Hu Jianbo , Qi Zhaoyu
Published: January 2021

In the field of maritime law enforcement, it is a key technology to achieve stable tracking of the black smoke exhaust of ships. Based on correlation filter tracking algorithm, a novel ship black smoke exhaust tracking algorithm is proposed. The proposed algorithm can complete the real-time tracking of ship black smoke exhaust. In addition, it can be transplanted to mobile devices, which can quickly and efficiently complete the tracking and law enforcement of the ship’s black smoke, and provide convenient services for maritime law enforcement in the ship’s emission control area.
Distribution and speciation of phosphorus in surface sediments of the intertidal zone in the Yellow River Delta
Authors: Liang Baocui , Peng Shitao , Xu Wen , Xiong Hongxia , Zheng Tianli
Published: January 2021

For better understanding the phosphorus (P) cycle, it is essential to distinguish the contents of different P speciation in sediments. In the study, the content of total phosphorus (TP) in the sediments ranged from 88.80 to 227.56 μg·g-1, with an average of 138.42 μg·g-1. The content of inorganic phosphorus (IP) ranged from 84.21 to 224.26 μg·g-1, accounting for 88.74%-98.55% of the TP content, which was the main occurrence form in the intertidal sediments of the Yellow River Delta. the contents of phosphorus fractions in surface sediments were 37.06 to 106.35 μg·g-1 for detrital phosphorus (De-P), 2.99 to 34.39 μg·g-1 for exchangeable phosphorus (Ex-P), 5.27-106.06 μg·g-1 for iron bound phosphorus (Fe-P). On the whole, the existing forms of inorganic phosphorus could be ranked as follows: De-P > Fe-P > Ex-P > authigenic phosphorus (Au-P). The regression analysis between TOC content and various forms of phosphorus showed that TOC content was negatively correlated with De-P.
An analysis of the environmental pollution of A specialized coal terminal In Tianjin Port
Authors: Sun Lei , Qi Bin , Zhang Weiqian
Published: January 2021

In order to comprehensively evaluate thecurrent situation of air pollution control in bulk terminal, the measures and effects of atmospheric environmental management of a specialized coal terminal company in Tianjin Port are studied. Through field investigation, monitoring and data analysis, the current situation of atmospheric environment of the subjectswas quantitatively analyzed and compared with national standard. The results show that, under the premise of using spray, covering, Wind-proof net and other management measures during monitoring, the atmospheric environment and major characteristic pollutants at the boundary of the terminal operating area meet the standard requirements.
Analysis on Fees Matter in Asset Allocation Planning
Authors: Cui Peng , Wang Peimao , Liu Xia
Published: January 2021

The purpose of this paper is twofold: first, to discuss cost controls, including tax management, and second, to introduce methods for seeking professional help when needed. The more you pay in fees and commissions, the less you earn in return. Controlling costs is an important part of any investment strategy, and that includes a good tax strategy. Some people opt to hire a professional investment manager to help with this asset allocation process and to stay on track. The final part of the chapter discusses the advantages and disadvantages of hiring an investment adviser.
Canonical correspondence analysis of relationship between characteristics of phytoplankton community and environmental factors in Wolong Lake
Authors: Ma Shanshan , Lv Xingchen , Geng Shicong , Wang Guofeng , Yang Shuo , Gao Yu
Published: January 2021

For the purpose of exploring the evolution process of aquatic ecosystem in Wolong Lake, the phytoplankton community structure and water quality were surveyed at 20 sampling sites around the lake in April, August and October, 2019. The results showed that Chlorophyta, Cyanophyta and Bacillariophyta accounted for 39.7%, 26.5%, 20.6% of all the species, respectively. The species biodiversity indices (included Shannon-Wiener index, Margalef species richness index and Pielou index) increased first and then decreased from April to October, while the phytoplankton density decreased simultaneously. CCA revealed that pH, Turb, TP, T, NH3-N, CODMn, TDS and TN were the main environmental factors affecting the community structure of phytoplankton in Wolong Lake, among which TP, T and pH had a greater impact on Chlorophyta, Cyanophyta and Bacillariophyta, respectively.
The Screening and Identification of Heterotrophic Nitrified Aerobic Denitrifier in the Penaeus Vannamei Boone Aquaculture System without Water Renew
Authors: Yuncheng Xie , Shumin Wang , Xiao Lei
Published: January 2021

The experiments respectively take the artificial substratum (mesh) form the indoor aquaculture systems without water renew of Penaeus vannamei Boone as well as the mature bio-films. Through the complex inoculation on BTB ammonia, nitrite and nitrate medium, screened and obtained the library of the heterotrophic nitrified aerobic denitrifier. Selected 25 single colonies from the bacteria library of two membrane systems to conduct analysis based on the 16s rDNA PCR-RFLP and the results indicated that 50 colonies can be divided into 5 spectral types, in which 2 for the mesh, 3 for the coral sand. After sequencing, the blast comparison shows that all the heterotrophic nitrified aerobic denitrifiers are from the γ-proteobacteria (Gammaproteobacteria), where the bacteria on the mesh belong to the Acinetobacter sp.and Klebsiella sp.; while the bacteria on the coral sand belong to the Pseudomonas sp., Shewanella sp. and Klebsiella sp. According to the analysis on the phylogenetic tree, we know its evolutionary position is basically consistent with the traditional classification. Gram stain analysis indicates that all bacteria are red and belong to the Gram-negative bacteria. The research is of great significance for the selection of the heterotrophic nitrified aerobic denitrifier in the prawn aquaculture systems.
Simulation Study On The Influence of Roof Inclination On The Light Environment Of Solar Greenhouse
Authors: Yang Wenxiong
Published: January 2021

With the help of the first solar greenhouse light environment simulation software, the influence of different roof inclination on the light environment of solar greenhouse with the same ridge height is simulated. The results show that when the ridge height of greenhouse is constant and the inclination angle of roof changes, all the evaluation indexes in greenhouse change to different degrees. When the roof angle increases from 28 ° to 32 °, the cumulative light input on the floor and the total energy of light radiation in the greenhouse decrease by 22.4% and 11.7% respectively, and the uneven of light intensifies, which is not conducive to the growth of greenhouse crops. Therefore, it is not recommended to increase the inclination of the roof when the ridge height of the greenhouse is constant.
Effect of Modified Peanut Shell on the Removal of Cu(II) in Aqueous Solution
Authors: Peng Qin , Shi Guangyou , Yang Yan , Si Wantong , Li Qiang
Published: January 2021

The effective resource utilization of agricultural and forestry waste has always been a core issue in the field of environmental protection. In this study, nitric acid-potassium hydroxide (HNO3-KOH) was used to modify the peanut shell, and the effects of different adsorption time, initial concentration and exogenous Cr(III) addition on the adsorption of Cu(II) were investigated. The results show that the adsorption of Cu(II) on peanut shell raw material (HS-YL) and acid-base modified peanut shell (HS-SJ) was in accordance with the pseudo-second-order kinetic model. Isotherm study shows that HS-YL fitted Langmuir adsorption model, mainly exhibiting monomolecular and chemical adsorption. HS-SJ conformed to the Freundlich adsorption model, which was mainly controlled by multi-layer adsorption. Additionally, when Cr(III) and Cu(II) coexisted, HS-SJ could simultaneously adsorb two heavy metals in a large amount, showing stronger adsorption performance compared to HS-YL. Therefore, the acid-base combined modification method is one of the important ways to recycle peanut shells.
The influence of geological structure on the characteristics of groundwater pollution in the downstream of tailing pond
Authors: Si Wantong , Li Qiang , Ren Yanxia , Peng Qin , chen Quanzhou , Tian Mengjie , Cao Qingya , Yang Wanqing , Liu Jumei
Published: January 2021

A large number of high-concentration pollutants in the tailings pond polluted the local groundwater. The contaminated groundwater moves to the Yellow River (YR) 12 kilometers south of the pond through natural flow and diffusion. However, how close the contaminated groundwater to the YR was difficult to determine by visual inspection. Therefore, the groundwater quality was analyzed through borehole sampling, and the results show that the Nemero index of groundwater pollutants presents a puzzling V-shaped distribution from the tailing pond to the YR. Soil permeability analysis shows that the concentration of groundwater pollutants in the vicinity of the Yellow River had risen again, which was caused by the blockage of the clay layer in the alluvial plain of the Yellow River. The results demonstrate that the pollutants leaked from the tailings pond have reached the bank of the Yellow River. This pollution has already threatened the water quality of the Yellow River; corresponding measures should be taken to ensure the ecological safety of the Yellow River. It provides a scientific basis for solving similar environmental problems in future.