bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic simulation model for different type of wheeled mobile robotic drives on leveled surface
Authors: Patel P S , Trivedi R
Published: December 2020

Dimensions of wheel base, payload weight and geometry, and type of drive configuration are some of the major factors to be consider during prototyping of a mobile robotic drive. For analysing the effect of such factors, a dynamic simulation model valid for any drive configuration using simple, omni or mecanum wheels is discussed in this paper. Sub-systems to take into account the inertia, motor characteristics normal force, friction force and wheel slip are discussed. Preliminary simulation results for path anticipation, for a control algorithm, for a four wheels omni drive robot with uneven mass distribution and variation of normal force due to acceleration of the robot are also shown in this paper. The simulation model is developed in Simulink/MATLAB.
Design of work holding device for machining wheel hubs
Authors: Hemanth M , Dheeraj P R , Hamritha S , Rajesh B , Vamshi Krishna S R
Published: December 2020

Work holding device plays a significant role in the manufacturing of the component that is custom made for any operation. Over the past decade, there has been an increase in mass production and in turn, it has increased the demand for forged components. Wheel hub is an important component of an automobile. It connects the wheel assembly to the axle and the shaft. It is also responsible for the safety of the vehicle as well as the driver. The work holding is the primary issue of the machining operation to be challenged. The objective of this project describes the detailed definition of work holding devices and identifies several benefits that relate to the use of work holding devices in manufacturing. Some of it includes increase in production rate and cost reduction. Parts manufactured with precision and accuracy eliminates the inspection and quality expenses. It helps CNC or VMC machines perform operations by itself and serves the necessary purpose with minimal errors as there is not much of human interference. Implementing this kind of simple and effective mechanism in manufacturing sector drastically reduces the cost of labour and cycle time, thereby increasing the quantity and quality of production. The forged component already manufactured needs to undergo various operations with respect to its orientation. To perform required operation a special Collet system was designed and manufactured to the respective work holding.
Effect of combined U-shaped and semi-circular rib on heat transfer augmentation of solar air heater-A CFD study
Authors: Manjunath M S
Published: December 2020

This paper presents the numerical analysis on the impact of combined U-shaped rib and semi-circular rib on heat transfer augmentation of flat plate solar air heater system.The analysis is done using the ANSYS Fluent software for various flow Reynolds number ranging from 8000 to 17000. The ribs are placed alternately on the underside of heated plate for a fixed stream-wise pitch of 35mm. The rib height is so chosen that the diameter of semi-circular rib equals the rib height of U-shaped rib. The rib height (e) is varied as 2mm, 3mm and 4mm. The analysis reveals that the combined ribs augment the heat transfer to a maximum extent of about 1.67 times as compared to the smooth duct. Ribs of greater height are found to produce greater enhancement in heat transfer due to increased flow mixing effect. The friction factor is found to increase with rib height and the highest increase is found to be about 1.73 times as compared to smooth duct for Re=8000.
Optimization of milling process parameters of aluminium alloy LM6 using response surface methodology
Authors: Shivakumar M R , Hamritha S , Shilpa M , Mirunalini  , Gouda Kavya S
Published: December 2020

This paper discusses the use of response surface methodology (RSM) for maximizing Metal Removal Rate (MRR) and minimizing Surface Roughness (Ra) in machining LM6 alloy material. The levels of three machining parameters spindle speed, feed rate and depth of cut are optimized during end milling operation. RSM is used for this experimentation. The regression models are developed and effect of each parameter on MRR and Ra is identified through the regression models. The results are analyzed through response surface and contour plots. The significant parameters are identified through Analysis of Variance (ANOVA) for MRR and Ra; all three parameters are significant for MRR, whereas spindle speed and feed rate are significant for Ra. Response surface optimization shows that the milling parameters are 2550RPM, 0.202mm/rev and 1mm for spindle speed, feed rate and depth of cut respectively. The maximum value for MRR is 0.043kg/min and that for surface roughness is 2.007μm at optimal parameter levels.
Evolution of the East Asian winter land temperature trends during 1961–2018: role of internal variability and external forcing
Authors: Gong Hainan , Wang Lin , Chen Wen , Wu Renguang
Published: December 2020

Detecting the contributions of internal variability and external forcing to the evolution of surface air temperature (SAT) trend at regional scales is a challenge. Based on the observations and large-ensemble simulations of climate models, we estimate the contribution of the internal and forced components to the evolution of East Asian winter land SAT (EAWT) during 1961–2018. Although the external forcing induced EAWT trends show a slow increase, both the total and internally generated EAWT trends exhibit a decrease with the extension of the time period, suggesting a critical role of internal variability in the evolution of the EAWT trends. The internal variability contributes to about 70% of total EAWT trends during 1961–1995. With the extension of the time period, the contribution of internal variability decreases, whereas the contribution of external forcing gradually grows to dominate the EAWT trends. Based on the dynamical adjustment method, we identify that the internal dynamics and forced thermodynamics account for a majority of internal and forced EAWT variations, respectively. We further identify that the multidecadal fluctuation of internal component of autumn Arctic sea ice is a critical precursor of the internal variability, especially the internal dynamically induced EAWT variations, through triggering a meridional stationary Rossby wave response in the following boreal winter. Our findings provide an insight into the understanding of the present and future climate change over East Asia.
Plastic in global rivers: are floods making it worse?
Authors: Roebroek Caspar T J , Harrigan Shaun , van Emmerik Tim H M , Baugh Calum , Eilander Dirk , Prudhomme Christel , Pappenberger Florian
Published: December 2020

Riverine plastic pollution is of global concern due to its negative impact on ecosystem health and human livelihood. Recent studies show a strong link between river discharge and plastic transport, but the role of floods is still unresolved. We combined high-resolution mismanaged plastic waste data and river flood extents with increasing return periods to estimate flood-driven plastic mobilisation, from local to global scale. We show that 10 year return period floods already tenfold the global plastic mobilisation potential compared to non-flood conditions. In the worst affected regions, plastic mobilisation increases up to five orders of magnitude. Our results suggest a high inter-annual variability in plastic mobilisation, previously ignored by global plastic transport models. Flood defences reduce plastic mobilisation substantially, but regions vulnerable to flooding often coincide with high plastic mobilisation potential during floods. Consequentially, clean-up and mitigation measures and flood risk management are inherently interdependent and need to be managed holistically.
The full spectrum of AdS5/CFT4 II: Weak coupling expansion via the quantum spectral curve
Authors: Marboe Christian , Volin Dmytro
Published: December 2020

We continue the effort to optimise and generalise the solution of the spectral problem of AdS5/CFT4 in the planar limit via integrability. We present a simple strategy to solve the quantum spectral curve (QSC) perturbatively for general states by focussing on the P
μ-system. A Mathematica notebook with an implementation of this algorithm is provided, as well as an extensive database with a user-friendly interface containing more than 8000 solutions of the QSC. When investigating the solution space, we observe a curious phenomenon: existence of solutions for which the Q-system degenerates in the limit g → 0. These degeneracies are lifted at higher orders in perturbation theory. The degenerating solutions have auxiliary Bethe roots merging with branch points at weak coupling.
Climate and Weather Extremes in the Volga Federal Region
Authors: Perevedentsev Y P , Sherstyukov B G , Guryanov V V , Shantalinskii K M , Auhadeev T R
Published: December 2020

Climate and weather extremes observed in the Volga Federal Region (VFR) are studied in relation to the climatic changes taking place in the XX – XXI centuries. Weather observation data from 183 meteorological stations and ERA5 reanalysis data are used as a source material. It has been demonstrated that a significant jump in the annual temperature mean was registered, the number of large-scale positive anomalies exceeded the number of negative ones, the quantity of hot days grew, while the quantity of ice days dropped in the VFR at the turn of the XXI century. The dynamics of hazardous weather events (strong winds, convection phenomena) was characterized by a positive trend on the territory of the VFR within the period from 1991 to 2018.
Main modes of the Arctic Ocean circulation and a relationship between their trends and the Atlantic water heat content
Authors: Platov Gennady , Kraineva Marina , Golubeva Elena
Published: December 2020

A study is presented on integral variability in Arctic Ocean characteristics, such as the volume transport and the heat content of the Atlantic water (AW) layer, obtained as results of numerical simulations using a model, SibCIOM. On the basis of an EOF decomposition three non-degenerate modes are obtained for the integral stream function and three modes for the heat content of the AW layer in the Arctic. Considering the cross-correlations of the EOF principal components a 44-yr cycle is obtained. It relates the cyclonic circulation mode in the Arctic and the second mode of AW heat content, associated with the AW warming in the area of the Beaufort Gyre. The Atlantic Multi-decadal Oscillation (AMO) statistically can act as a source of such a cycle, however, the thus obtained correlation is at the limit of the admissible significance, and the period of AMO oscillations is 1.5-2 times longer. In our opinion, a relationship with fluctuations in the Atlatic Meridional Overturning Circulation (AMOC) seems to be more plausible. However, no understanding of the role of these two mid-latitude and polar processes in relation to what extent they act as a cause or a consequence has yet been established in this study.
Short-range forecast of heavy rainfall over the Kama River basin in 2019 with atmospheric models ICON, GFS and WRF
Authors: Shikhov A N , Bykov A V , Abdullin R K
Published: December 2020

The summer of 2019 was one of the wettest in the observation history in the western part of the Ural region. Excessive rainfall formed several rain flood events on the rivers of the Kama reservoir basin. In this study, we assess the accuracy of short-range (with a 15-27 h lead time) forecasts of heavy rainfall events observed in 2019 with global numerical weather prediction (NWP) models, ICON and GFS, and a mesoscale model, WRF, launched in a convection-permitting mode. Two metrics, Critical Success Index (CSI) and Extreme Dependency Score (EDI), are used to assess the forecast skills of the global NWP models. Throughout the study period, both global NWP models underestimate the frequency and intensity of heavy rainfall events, mainly due to the omission of local rainstorms. However, heavy precipitation related to cyclones or frontal waves is predicted quite successfully. In addition, we analyse in detail a heavy rainfall event on July 14-16, 2019 which caused a high flood in the western part of the Perm region. The most reliable simulation results have been obtained with the WRF model.
Microplastics in the snow cover of the south of Western Siberia
Authors: Malygina N S , Biryukov R Yu , Kuryatnikova N A , Mitrofanova E Yu , Pershin D K , Zolotov D V , Chernykh D V
Published: December 2020

Plastics production is growing all over the world, but the total emission of microplastics is unfortunately not reducing. In the external environment, plastics degrade over time. This leads to the appearance of smaller particles or fibers which are microplastics at sizes of less than 5 mm. Atmospheric transfer is for microplastics one of the main ways of entering the environment. The purpose of this study is to identify microplastics in the snow cover of the south of Western Siberia, as well as preliminarily assess the possible sources of their supply. Snow samples are taken during a period of maximum snow accumulation (March, 2020) according to requirements developed by the Norwegian Institute for Air Research. The microparticles are visually evaluated using a digital microscope, Dino-Lite AM211, a fluorescent dye solution, and a Wood lamp. To assess the possible atmospheric distribution and deposition of the particles, an analysis of the synoptic conditions based on data of NCEP/NCAR, ERA5, and HYSPLIT is performed. The microscopic analysis has shown that microplastics (namely, films, fibers, and granules) have been detected in 16 of the 18 snow samples in the city of Barnaul and adjacent territories, as well as fibers and granules have been revealed in 3 snow samples from the Kasmala River basin.
Ice rains in the Middle Urals
Authors: Kalinin N A , Sviyazov E M , Pomortseva A A , Pischalnikova E V
Published: December 2020

This article is devoted to ice rains in the Urals. The occurrence of events in the cold period of 2019-2020 is considered. The diurnal course of an event is revealed, and the frequency of the accompanying ice is established. The physical and synoptic conditions of ice rain are studied. A comparison of the state of the atmosphere during a period of ice rain, freezing precipitation and in the absence of phenomena is carried out. Radar data of ice rain events which cause heavy ice and significant material damage are presented. It has been found that the ice rains in the Middle Urals are formed under the influence of a warm front and in the warm sector of a cyclone. This event is mainly recorded during the daytime. The duration of the event is 31 minutes on average. The prevailing air temperature near the earth’s surface is -2.3 °C on average.
Applicability of reanalysis data to diagnosis of snow avalanches in the Caucasus Mountains
Authors: Kuksova N E , Toropov P A , Olenikov A D , Surkova G V
Published: December 2020

This work is devoted to assessing the use of reanalysis data for diagnosing the danger of avalanches using the Caucasus Mountains as an example. This method is applicable to entire mountain regions, not individual slopes, and uses the results of both observations and numerical modeling in the atmosphere. A comparison of observational and reanalysis data of Era-Interim, CFSR, and NCEP-NCAR is performed based on a classification of winters by using air temperature and precipitation data to assess avalanche hazard. The accuracy of the temperature and precipitation data and their influence on avalanche hazard are analyzed.
A platform approach to the organization of digital forest monitoring of the Baikal natural territory
Authors: Bychkov I V , Ruzhnikov G M , Fedorov R K , Popova A K
Published: December 2020

This paper describes a platform approach to the organization of digital environmental monitoring of the forest resources of the Baikal natural territory (BNT), some characteristics of the current state of forests in the BNT and schemes of organization of state environmental monitoring in a traditional format. Some features and problems of forest resources monitoring of the BNT that complicate decision-making are formulated. Some basic requirements for digital forest monitoring and types of digital platforms of different levels are considered.
Geospatial meteorological and climatic data services application programming interface
Authors: Titov A G
Published: December 2020

At present, it becomes necessary to develop software for Earth science data repositories instead of downloading data to computational servers and workstations. This is especially important taking into account the upcoming volume of big environmental datasets. WPS (Web Processing Service) is an OGC standard for distributed geospatial data processing services. The WPS services provide access to geospatial data processing packages including statistical processing software tools. The main goal of this paper is to present an approach that provides a unified access to the web processing services developed for climate and meteorological research based on the latest technological and scientific achievements. Based on the “OGC API-Processes” standard, a Web API Climate is proposed to provide a uniform access to the “Climate” platform (http://climate.scert.ru/climate/environment/v3.0a-demo/) geospatial services. The Climate Web API provides a software basis for an advanced development and use of the “Climate” platform web processing services aiming at climate change studies at regional and global levels. A correct implementation of the specification will form a solid foundation for further development of desktop client applications in the form of GIS plugins, as well as universal Web-GIS clients easily embedded into thematic virtual research environments.
Local climate zones in the city of Nur-Sultan (Kazakhstan) and their connections with urban heat island and thermal comfort
Authors: Berlessova A A , Konstantinov P I
Published: December 2020

Nowadays, under the conditions of modern development, an increase in population leads to a significant increase in urban settlements with their specific characteristics, which in turn may have a significant impact on the formation of special microclimatic conditions within cities. Due to territorial expansion of cities, most of them are developed at a significantly high speed, which may lead to dramatic changes both for the residents and for the environment within the cities. Since urban planning has been developing for a rather long time, there are many ways to regulate this process by taking into account local physical and geographical features. This work is devoted to relationships between various microclimatic indicators of changes in the structure of buildings. It is shown that an increase in the share of compact high-rise (local climate zone (LCZ)-1) and mid-rise (LCZ-2) buildings is reflected in an increase in the intensity of the urban heat island, both in average annual (+0.4…+0.5°C) and seasonal variations (+0.75°C for summer). This in turn causes an increase in the PET (Physiological Equivalent Temperature) thermal index (increasing of frequency of strong and extreme heat stress conditions) and a decrease in the UTCI (Universal Thermal Climate Index).
Sky View Factor (SVF) assessment in a real-time system for thermal comfort conditions monitoring in the Moscow region
Authors: Perkhurova A A , Varentsov M I , Samsonov T E , Kargashin P E , Korosteleva P A , Konstantinov P I
Published: December 2020

Comfort indices are used to assess the harm to human health caused by unfavorable thermal conditions. All calculated indices are based on both meteorological and physiological parameters. An algorithm is used which is based on a model RayMan for calculating two of the most common thermal indexes: PET and UTCI, which are based on a balance of human energy or models of human heat fluxes. The purpose of this research is to develop a real-time system of calculating comfort indices based on data of a web service for monitoring weather conditions in Moscow and the Moscow region. The technology is based on the use of specialized libraries of the Python language (pyautogui, pywinauto) to interact with the keys of a keyboard and a mouse, because it is necessary to write paths to files and make keystrokes in the model. The result is presented in a visually understandable form with a spatial distribution of the thermal stress in the form of points with signed index values at the locations of weather stations throughout Moscow and the surrounding areas. A test of sensitivity of the RayMan model to changes in a sky view factor (SVF) is also carried out. It is shown that the PET index is more sensitive to changes in SVF than UTCI. An assessment is made of the summer frequency of occurrence of cases with unfavorable levels of the thermal stress (taking into account SVF) at stations of the Roshydromet network in Moscow and the Moscow region. It is shown that during the controversial summer of 2019, the points where strong and extreme heat stresses most often occurred are located within the territories of Domodedovo and Sheremetyevo airports.
The effects of wind on the generation of surface wave in a shallow water
Authors: Fauzi Rifky , Wiryanto L. Hari
Published: December 2020

In this paper, the generation of surface waves by wind is modeled using an extended shallow water model. Jeffreys’ sheltering mechanism is incorporated to model the wind action on the surface. This modification allows the model to have a wave grow or decay mechanism under the action of wind. The wave generation or damping is investigated by calculating critical wind velocity to excite oscillatory waves on the surface. The result shows that critical wind is proportional to a numerical constant, namely the sheltering coefficient, which related to the capability of wave overcome the wind gust. Thus this model has the convenience that the critical wind speed may comparable to physical data for a suitable choice of this constant.
Miocene Sea Surface Dynamics in the Western Equatorial Pacific Based on Calcareous Nannofossil Records
Authors: Yuwono Fareza Sasongko , Sato Tokiyuki
Published: December 2020

Calcareous nannofossil in the sediments from Ocean Drilling Program (ODP) Hole 806B in the Ontong Java Plateau have been examined to reconstruct surface water condition in the western equatorial Pacific (WEP) throughout the Miocene. By using quantitative techniques, 107 sediment samples have been prepared into nannofossil slides and observed under microscope. Changes inReticulofenestrasize variations,Discoasterrelative abundance and nannofossil accumulation rates (NAR) suggest that WEP surface water was dynamic. During early to middle Miocene from 18 to 14 Ma, the surface water was warm and depleted in nutrient with deep thermocline due to warm period of the Middle Miocene Climatic Optimum. Temperature cooled, nutrient increased and thermocline shoaled at 14 Ma during the East Antarctic Ice Sheet Expansion (EAIE). Surface water warmed and thermocline deepened after 13.2 Ma as the western Pacific warm pool (WPWP) began to established. At 9 Ma, surface water suddenly changed into cooler and nutrient rich condition. The collapse of ocean stratification coincided with the onset of Asian Monsoon Intensification. Warm surface water and deep thermocline occurred again in the latest Miocene as the brief return of the WPWP during 7–6 Ma.
Study of tidal effect on water mass stratification in Mahakam estuary using 3D hydrodynamic model
Authors: Wiyani R I , Mandang I , Mubarrok S
Published: December 2020

Mahakam Delta is a delta with unique characteristic. As a result of the continuous sedimentation process, the delta can be said as a complex delta because it has dozens of tributaries that are interconnected and flow into the sea to their estuaries. Mahakam Delta estuary is a meeting place for mixing masses of water from freshwater rivers and high salinity rivers. The aim of this study is to determine the water column stratification seen from the salinity and temperature parameters in the Mahakam Delta estuary. This study uses the ECOMSED model which is run for 40 days (July 7 to Augustt 16, 2018) with tides and river discharge as the generating force. The simulation results show that stratification is predominantly influenced by differences in salinity between the layers. The strongest stratification is located in the northern Mahakam Delta line with a difference in salinity is 8 psu from surface to bottom layer.
Tropical marine Navicula salinicola NBO: morphology, genetic identification, and biochemical properties
Authors: Rachmayanti Y , Mwebaza H , Radjawane I M , Nurachman Z
Published: December 2020

Indonesia’s oceans are rich in microalgae as unicellular photosynthetic organisms. So far, most of Indonesia’s diverse microalgae have yet been explored. An Isolate NBO of microalgae has been collected from Bokor Island in the Jakarta Bay, Indonesia. This study aimed to identify the isolate NBO and to characterize its biochemical properties. The identification was carried out based on the physical morphology of cell and the nucleotide sequence of 18S rDNA-V4 and LSU D2/D3 DNA regions, meanwhile, the biochemical properties were characterized based on the content of carbohydrate, lipid and fatty acid of cells. The results showed that the morphological characteristics of NBO cells possessing a color of pale yellow, an oval shape ranging from 11.00–15.00 μm in length and 4.67–5.00 μm in width, and a silica frustule that bilaterally symmetrical oval closed to genus Navicula. Based on the homology of sequences 402-bp of 18S rDNA-V4 and 591-bp of LSU D2/D3, the isolate was identified as Navicula salinicola. Total carbohydrate and lipid contents of Navicula salinicola NBO were 13.13 and 3.74% (w/w), respectively. Fatty acids of Navicula salinicola NBO were dominated by palmitic acid (C16:0), palmitoleic acid (C16:1), and eicosapentaenoic acid (EPA; C20:5) with a total concentration of 38.24, 37.23, and 12.54% (w/w, fatty acid/lipids), respectively, indicating a promising candidate for biodiesel and nutrition/ pharmaceutical.
Studying Sea Level Variability in Indonesia Sea Based on Satellite Altimetry
Authors: Sarsito Dina A , Syahrullah Muhammad , Wijaya Dudy D , Pradipta Dhota , Andreas Heri
Published: December 2020

Sea level variability is one of the fundamental parameters for scientific development such as modeling the Earth’s climate. In addition, this parameter also playing crucial rules to mitigate socio-economic hazards due to sea-level changes, especially in coastal areas. Mitigating the sea-level hazards in an archipelagic country like Indonesia becomes more essential since the country is geographically constructed by various bathymetric depths with different types of seas. One of the attempts to study sea-level variability is to take benefit from satellite altimetry data. The satellite altimetry missions have observed the sea level more than 25 years, and hence the rate of sea-level variability can thoroughly be studied by comparing Mean Dynamic Topography with Sea Level Rise in the research area. The result shows positive and negative correlation in several areas that can be examined as regional-scale variations in sea level over the Indonesian sea.
Research on Exploration and Application of Wind Energy
Authors: Huang Jin
Published: December 2020

At present, coal is the most important resource for utilization and development in China, but the environmental pollution caused by coal is serious. It is urgent to improve the development of clean energy. China is gradually promoting wind energy, the development and utilization of wind energy is difficult. The difficulty of storing wind energy and its instability limit the country’s spread. Wind energy can only be developed better by solving the current problems. The research on the development and utilization of wind energy also becomes the key to solve the problem.
Design and development of turbine blade classification management system based on PDM
Authors: Ma Lyuzhou
Published: December 2020

According to the requirements of modern enterprises for the classifying and managing system of product information, the structure of the flexible classifying and managing system based on internal and external codes is putted forward, the function and effect of every part are particularized, which was applied in the implementation of the PDM of turbine blade. It is shown from the application that classifying and managing system can promote the development of information in the enterprise.
Development Situation and Relevant Inspiration of Pumped Storage Power Station in the world
Authors: Luo Youkun , ShengXin  , ZhiyuanQiao
Published: December 2020

In many countries, pumped storage power stations have gradually become management tools for the power system and are used to meet peak-shaving, valley filling and emergency reserve purpose. In addition, pumped storage power stations can be taken advantage of the unique valley filling function to facilitate the development of wind power, such as in Germany, one of the main approaches to digesting and saving wind power is to maintain a high share of pumped storage power generating capacity. Main factors affecting the scale and share of pumped storage power generating capacity include level of economic development, regional load characteristics, power mix and the peak-shaving capacity of interconnected systems. The capacity of pumped storage power stations is also affected by construction conditions, cost and the economics of other peak-shaving approaches of the power system. In China, the construction of pumped storage power stations is entering a fast-growth period. The government should incorporate the construction of pumped storage power stations into its long and medium-term power development plans and regard pumped storage power stations as part of regional power system. In addition, all of the functions offered by pumped storage power stations should be compensated by ancillary services supporting schemes.
Research on filter parameter optimization method of grid-connected photovoltaic system
Authors: ZhuoqunZhao  , HongjunWang  , Zhao Hui
Published: December 2020

With a large number of distributed energy and nonlinear loads such as photovoltaic and wind power are connected to the power grid, while improving the energy structure of the grid, it also greatly increases the harmonic content in the power grid, resulting in the decline of power supply quality and stability. In this paper, based on the analysis of the working principle of photovoltaic power generation system and the characteristics of the filter connected to the power grid, taking the inverter composed of high-frequency power electronic devices as an example, the principle of high-order harmonic generation is analyzed. According to this, a T-type filter is designed to suppress harmonics. The relationship between thd and filter parameters is studied, and the optimization method of T-type filter parameters is proposed Law.
Performance Analysis of SOFC / GT Combined Cycle System with Preheater in Front of Turbine
Authors: Xingsheng Lao , Mengran Liao , MaCan  , Chunhui Dai
Published: December 2020

Based on the SOFC zero-dimensional model, a SOFC turbine combined cycle simulation platform is established. For the SOFC/GT combined cycle system configuration scheme with the preheater placed in front of the turbine, the influence of cycle parameters on system performance is analyzed. The current density-power characteristic curves at different outlet pressures, the fuel flow-efficiency characteristic curve and the turbine inlet temperature curve at different fuel utilization rates were calculated and analyzed separately when different low-temperature and intermediate-temperature combined cycle system configurations were used. The results show that the low-temperature SOFC/GT cycle maintains high-efficiency design conditions with a fuel utilization rate of 0.8-0.85, and the highest efficiency is about 52%. The design working pressure of the medium temperature SOFC/GT cycle is suggested to be 0.4MPa-0.5MPa, and the system efficiency will be higher than 50% when the compression ratio is at 0.8-0.85, and the maximum efficiency is about 64%.
Sedimentary characteristics and hydrocarbon potentials of longitudinal gravity flow deposits in the east subsag of Saihantala Depression
Authors: Yanchen Guo , Xuntao Yu , Yawen Xing , Heqing Feng
Published: December 2020

Nowadays, Longitudinal gravity flow deposits, as a kind of important deep-water reservoirs, can form a certain scale of lithologic oil and gas reservoirs, which is of fundamental significance in the exploration of oil in Saihantala Depression. The evolution and sedimentary characteristics of the longitudinal gravity flow in the east subsag of Saihantala Depression are analyzed based on the core date, well logging, seismic data, regional geological data, and the method of seismic sedimentology. The sedimentary model of the longitudinal gravity flow and the exploration potential of the lithologic reservoir of longitudinal gravity flow are also discussed. The reservoir is mainly composed of medium-fine sandstone with developed secondary pores. The geological conditions for the formation of axial gravity flow are sufficient provenance, the development of slope breaks and the negative axial topography. The updip direction of the longitudinal gravity in the area has a short extension of the sand body, and the downdip direction has thick massive fine sandstones, which opens up pathways for lithologic reservoir exploration.
Model Predictive Current Control of Dual-Permanent-Magnet Vernier Motor based on Anti-Windup Controller
Authors: Liu Yushun , Zhu Taiyun , Wu Shaolei , Li Senlin , Wu Binyu , Huang Zhifan
Published: December 2020

Dual-permanent-magnet vernier motor incorporates the merits of high torque density and low cost, suitable for low-speed high-torque applications. Due to integral saturation and high current ripples in dual-permanent-magnet vernier motor control system, a model predictive current control strategy based on Anti-Windup PI controller is proposed. Adaptive adjustment variable structure is adopted in integral segment of the controller, which can quickly eliminate integral saturation in system. Mode predictive current control based on dual vector is adopted in current interior loop of the system, double arbitrary voltage vector can be selected to operate simultaneously in each control cycle that extends selection range of voltage vector and adjustment range of amplitude, which can realize more accurate current control. Meanwhile, considering system delay, current delay compensation is added to predictive control. The simulation results showed that proposed control strategy can effectively restrain integral saturation, reduce current ripples, thus improving dynamic and steady state performance of the control system.
An Effective Algorithm for Economic Dispatch of Power System with Prohibited Operating Zone
Authors: Wang Shibo , WeiTeng  , Wang Nan , Cheng Yan , Sun Shumin , Xing Jiawei , Wang Yanzhuo
Published: December 2020

In the actual operation of the power system, some generating units may have physical limitations. For a unit with prohibited operating zone, its operation zone [Pmin, Pmax] will be divided into several discrete sub feasible regions. In this paper, the influence of units with prohibited operating zone on the system is deeply studied, and the influence of units with prohibited operating zone on other units in the system, including the influence between units with prohibited operating zone, and the optimal solution state of economic dispatch problem for units with prohibited operating zone are further studied. Then the iterative algorithm for the above three problems is modified. At the same time, the economic law and physical essence of the economic dispatch problem for units with prohibited operating zone are explored. With high calculation efficiency, the algorithm proposed in this paper has its own engineering application value.
The application of Cr-MOF@MWCNT modified separator in high-performance lithium-sulfur batteries
Authors: Ma Bingqing
Published: December 2020

Lithium-sulfur batteries have attracted attention when competing with the next-generation of rechargeable batteries due to their higher theoretical specific capacity, lower cost, and non-toxic and harmless feature. However, there are many obstacles towards the practical application of lithium-sulfur batteries such as low conductivity of the positive electrode and discharge products, the “shuttle effect” of polysulfides, and the unsafety of the lithium negative electrode. In this paper, Cr-MOF@MWCNT as a separator modification layer is introduced into lithium-sulfur batteries to solve the problem of “shuttle effect”. The Cr-MOF in the coating layer can adsorb polysulfides, and the MWCNT tightly combined with Cr-MOF helps to build a good conductive network, so that the adsorbed polysulfides can be converted. As the initial specific capacity and cycle stability of lithium-sulfur batteries with the Cr-MOF@MWCNT separators have been improved, the initial specific capacity is as high as 1377 mAh g−1 at a rate of 0.2 C, while the average capacity attenuation per cycle after 300 cycles is 0.14%, with 99.8% of coulombic efficiency.
Analysis of Rapid Demand Variation in Electric Vehicle Industry based on Innovation Diffusion Theory
Authors: Li Jiping , Zhang Jingjing , Zhao Zhihong
Published: December 2020

The emerging industries are usually driven by innovations and represent the development directions of advanced economic. Particularly, this manuscript explores the innovation diffusion and S-Curve theoriesto study emerging industries which are characterized with rapid demand variations, where the new energy vehicle industry serves as an example. The S-Curve is deduced in detail as a theoretical foundation for the study of the rapid demand changes of emerging industries. Base on authority data of vehicle sales in past decades, the NPS and EV30@30 scenarios from IEA are analysed to reveal the worldwide trend of electric vehicle industry. And as the largest market of new energy vehicles in the world, Chinese electric vehicle industry exhibits obvious impetus of government policies on the market development, and foresees a significant penetration of electric vehicles into traditional transportation sector in near future.
Research on Valve Characteristics and Economic Operation of Ultra-Supercritical Steam Turbine with Throttle Steam Distribution Mode
Authors: Lili Zhou , Jianqun Xu , Xijun Huang , Zeyu Huangfu
Published: December 2020

High pressure governing valve is modelled by elliptic equations, and verified through the comparison with the literature data. Then a 660MW ultra-supercritical steam turbine with throttle steam distribution mode is modelled to explore the efficiency of HP cylinder and the unit’s economic under different loads with different operation strategies. Analysis shows that the valve opening is an important factor that impacts the heat rate and the valve in 30%-40% opening should be recommended for operation. According to the requirements of grid frequency adjustment, the proposed operation strategies can improve the units’ economic performance and enhance the ability of deep peak regulation.
Analysis of land use change in Xi’an based on GIS and RS
Authors: Bei Xue , Shujing Gao , Xiuqin Zhang
Published: December 2020

Along with fast economic growth, population increase and accelerated urbanization, the land use pattern of Xi’an is experiencing tectonic changes. Studying the land use change volume and spatial distribution in different regions in Xi’an will provide a basis for future studies on the urban spatial arrangement, land use management optimization and sustainable land use development. Based on GIS and RS technologies, this study explored the land use changes in Xi’an, analyzed the type, quantity, spatial arrangement and density of land use change, and introduced quantitative parameters including the dynamic level of land use, the transfer matrix, etc., for analysis. The results revealed that: 1) the major land use types in Xi’an were farmland, forest and built-up land; 2) in these 15 years, the area of grassland and built-up land increased, while the area of farmland decreased; 3) the dynamic level of comprehensive land use change increased, indicating intensive land use changes in Xi’an.
Optimization of the delivery route for community group-purchasing fresh products considering customer satisfaction
Authors: Wang Yong , Qiu Wei
Published: December 2020

For this paper, the VRP model on the total cost minimization of fixed cost, transportation cost and penalty cost is developed under the constraint of the delivery time satisfaction function for the characteristics of community group purchasing. On the genetic algorithm optimization, an elite retention mechanism is added, a partial crossover rule is used to design the crossover operator, and the examples are tested. The results show that solving the total cost function can effectively reduce the cost, and the improved genetic algorithm has good computational speed and convergence. At the same time, good satisfaction was obtained, indicating that the company cannot neglect the customer satisfaction experience while pursuing the minimum total cost, which provides a decision reference for achieving the balance between the two.
Research on Vehicle Trajectory Tracking Control in Expressway Maintenance Work Area Based on Coordinate Calibration
Authors: Yong Huang , Daqing Fang , Fuliang Tan , Minglu Tao , Daoguang Si , Yang Shu
Published: December 2020

In the highway maintenance work area, how to reduce traffic congestion and traffic accidents caused by vehicle changing lanes has become a continuing research issue. This research focuses on the lane-changing behavior of vehicles in the highway maintenance work area. By changing the lane-changing trajectory of vehicles under different lane numbers, it can intuitively understand the influence of different lane numbers on lane-changing characteristics. Studies have shown that when the number of highway lanes increases, the distance between the starting point of the vehicle lane change and the highway maintenance work area will increase. At the same time, the probability of changing lanes in front lanes that are barrier-free and does not need to change lanes decreases as the number of overlapping lanes increases. Under the condition of the same number of lanes, the closer the distance between the vehicle and the obstacle lane, the more convergent the lane-changing trajectory of the vehicle, and the probability of lane-changing greatly increases.
Study on the Speed Limit at Night in Expressway Maintenance Area
Authors: Huang Yong , Fang Daqing , Tan Fuliang , Tao Minglu , Si Daoguang , Shu Yang
Published: December 2020

In order to improve the safety of expressway maintenance work area at night, taking the maintenance work area of two-way four lane Expressway in Anhui Province as an example, the traffic characteristics of the maintenance work area at night are analysed, and the variation characteristics of vehicle speed in the maintenance work area are studied, and the main factors affecting traffic safety are obtained. Based on the traffic flow theory and Greenshields speed density-linear relationship model, this paper analyses the correlation between the speed and traffic capacity in the maintenance work area. Through the simulation by VISSIM software, the speed limit value of the expressway maintenance work area in the day and night is obtained, which provides an important reference value for the expressway maintenance operation.
The electrical energy usage of monitoring system at real-time using IoT as the primary policy of energy efficiency
Authors: Suhanto  , Setiyo Prabowo Achmad , Indrianto Sudjoko Rifdian , Suryono Wiwid
Published: December 2020

The policy of electrical energy conversion requires an energy audit to be right on target. Energy audits require measuring devices and energy usage data recorders in every part of the system. Measurement and recorder integration is using the technology of the Internet of Things (IoT) can facilitate the collection, monitoring, and data analysis. This research is designed and implemented for monitoring the use of electrical energy in real-time by utilizing IoT at a low cost. This system includes a microcontroller that is can communicate via WiFi network type ESP32 Devkit V1, instrument system of measuring electrical energy type PZEM-004T, the connector and wrecker device use Solid State Relay (SSR) and open-source IoT platform. The finding showed that the developed energy monitoring system can successfully record voltage, current, active power, and accumulative power consumption. The monitoring system can be acquiring the power used by the load relatively fast is around 2 to 4 seconds, and the monitoring system uses relatively little power around 5 W.
Development of control systems on vacuum evaporators with 50 l capacity to reduce honey water content accordance to sni 01-3545-2004
Authors: Nazaruddin N. , Hapsoh  , Darmawan A I
Published: December 2020

Riau still has many protected forests and nature reserves. One of the wealth of protected debt is the forest’s Honey. One of the weaknesses of forest honey is the high water content in honey. The permissible water content in honey is 22% based on SNI 01-3545-2004. This paper presents a vacuum evaporator of control system design as a tool for reducing the water content in Honey. The control system design is made such that the honey temperature in the evaporation process is no more than 40°C. There are three quantities that are controlled in this process, namely vacuum chamber pressure, temperature and screw rotation. Temperature control system and pressure control system use close loop system, while the control system for screw rotation uses open loop system. The three main components of this control system are the VE 115N vacuum pump, the stirring screw motor with 1 HP power, 2 heaters with 250 watts of power each, Temperature Control (Eliwell IC901 thermostat and thermistor sensor), 35x25 panel box. To meet the quality of honey, the control system is set with a maximum temperature of heating water 40°C and vacuum pressure at 7.4 kPa and screw rotation at 60 rpm
Hybrid electric vehicle power consumption analysis in tropical area
Authors: Heryana Ghany , Sumarsono DA , Adhitya Mohammad , Nazaruddin N , Siregar Rolan , Zaenuri Fuad , Prasetya Sonki
Published: December 2020

Internal Combustion Engine (ICE) is one of the biggest fossil fuel consumers. Many attempts have been made by researchers to replace ICE with electric motors and batteries as a source of energy. On the other hand, the dependence on ICE cannot be eliminated. One of the better ideas is to combine an ICE with an electric motor or called a hybrid. This study aims to determine the amount of energy consumption used by Hybrid Electric Vehicles (HEV) in urban areas in a tropical megapolitan city. The method used is to monitor the use of energy in hybrid cars directly. Sensors and data acquisition are installed on the vehicle to find out the route, speed, fuel consumption, electricity consumption, etc. Data acquisition is also placed on pure ICE vehicles with comparable engine capacity. Previous research, namely the analysis of energy consumption in the Plug-In Hybrid Electric Vehicle (PHEV), will also be used as a comparison. The results obtained indicate that HEV could travel 22 kilometers with one liter of gasoline. ICE car could cover 13 kilometers by 1 liter of petrol. And PHEV could travel 34 kilometers with 1 liter of gasoline. Thus it can be concluded that HEV has the advantage of saving gasoline usage, but PHEV is the best of them.