bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on economic dispatch based on improved firefly ag-orithm
Authors: Wang Xingang , Kai Saijiang , Zhang Feng , Sun Licheng , Huang Ping
Published: April 2021

An improved firefly algorithm for solving the economic dispatch problem of power system is proposed. The algorithm considers the climbing rate, the dead zone and other constraints, and calculates the network loss. This algorithm is based on the firefly algorithm, a new repair strategy for active correction of the violation of the constraint condition of all kinds of fireflies, and combined with the penalty function technique, the fireflies in the feasible region or as close as possible to the feasible solution search in the area. The accuracy and speed of the algorithm can be effectively improved by greatly reducing the probability of finding the optimal location of the firefly in the infeasible solution region. The simulation results show that the algorithm has the characteristics of high speed, high accuracy and good convergence.
Structural Dynamics Simulation Analysis of Industrial Robot Arm Based on Kane Method
Authors: Luan Yizhong , Guo Junmei , Liu Haiying
Published: April 2021

When the traditional methods are used to analyze the dynamics of the robot arm structure, the stability of the arm structure is not good and the simulation effect of the operation process is not good. For this reason, Kane method is introduced in this paper to carry out dynamic simulation analysis of industrial robot arm structure. The operating process of the industrial robot arm structure was simulated by Kane method, and the angular acceleration of the robot’s main arm, forearm and push rod was solved in each cycle. The Jacobian matrix of the 5 degree of freedom manipulator joint is established, the singular configuration of each joint is calculated, and multiple joint variable combinations are generated by random number. The forward motion equation of the robot endpoint set was solved to obtain the endpoint set of the robot. The Lagrangian method was used to model the robot with Kane 3D simulation software to simulate and analyze the dynamic process of the driving torque required to grab the mass workpiece at the three joints. The joint motion model of robot is established on ADAMS simulation software, and the torque curve of the rotating joint of industrial robot arm structure is obtained. MATLAB simulation software is used for simulation. The results show that the integrated design method of manipulator and machine tool is correct, which provides a comprehensive data basis for the selection of servo motor.
Analysis for anodized film blackening of aluminum alloy components
Authors: Zou Xiaohui , Jiang Chengjun , Lv Chaojun , Sun Xiaojiao , Luo Jing , Chen Shumao
Published: April 2021

Sulfuric acid anodic oxidation is an important means to improve the corrosion resistance of aluminum alloy components. The blackening phenomenon of aluminum alloy components after sulfuric acid anodizing is analyzed by chemical composition test, mechanical property test, process parameters analysis, metallographic examination and other tests. The analysis results are compared with normal color components after anodized. The result shows that the unsufficient solid solution heat treatment is the main reason for anodized film blackening of the aluminum alloy components, which result in the abnormal microstructures. At last, the measure of secondary heat treatment is taken to solve this problem effectively.
Research on Feature Extraction of Local Binary Pattern of SLM Powder Bed Gray Image
Authors: Yin Yu , Liming  , Dali Guan
Published: April 2021

The quality of powder bed is one of the important factors that affect the quality of Selective Laser Melting(SLM) of parts. Image preprocessing method and defect identification method are proposed for recoater hopping during powder spreading by SLM. For the collected powder bed image, the Basic Mask method is designed to preprocess the image, uniform the light intensity distribution of the image and filter out the image noise. To extract the defect features accurately, different Local Binary Patterns (LBP) operators are used to classify and calculate the identification accuracy of each operator by Support Vector Machine (SVM). The recognition accuracy of this method is up to 98%.
Analysis of harmonic oscillator mass parameters influence on multiband gap widening for Drude model acoustic metamaterial
Authors: Shi Huijie , Gao Ming , Yin Song , Wu Shujiang
Published: April 2021

Acoustic metamaterial is a kind of special microstructure of man-made composite material with vibration attenuation band gap. In view of the band gap widening methods, the Drude model with additional double harmonic oscillators five periodic spring-mass system is established, and then the steady-state displacement and velocity of each oscillator under different external excitation frequencies were calculated, the vibration transmission characteristic of the system is obtained. The band gap widening method is analyzed. The results show that, compared with the Drude model, a new high frequency band gap is developed by adding double harmonic oscillators, and with the increase of the additional oscillator mass, the total bandwidth of low frequency band gap is widen. The research provides theoretical basis and application basis to the design of vibration isolation structure implement specific frequency band of noise reduction.
Comparative experimental study on phased array and X-ray detection of small diameter pipe weld
Authors: Xie Liming , Wang Tongle , Zhang Yanfei
Published: April 2021

According to the principle of ultrasonic phased array technology, the phased array inspection technology for butt weld of small-diameter pipe is developed. The ultrasonic phased array and ray inspection tests are carried out on the sample pipe of small-diameter tube with typical specification of heating surface in Inner Mongolia thermal power plant, and the evaluation results obtained by the two inspection methods are compared and analyzed. It can be seen from the comparison of testing results that ultrasonic phased array testing has more advantages than X-ray testing in defect detection rate and defect parameter measurement. At the same time, ultrasonic phased array testing also has the advantages of environmental protection, intuitiveness and high testing efficiency.
Effect of Rare Earth Yttrium on Thermodynamic Properties of 20MnSi Steel
Authors: Bai Zhiling , Qin Bingke
Published: April 2021

The Gibbs free energy of yttrium-containing compounds in 20MnSi steel is obtained by establishing a thermodynamic model and calculation. The results show that as the Y content increases, the oxygen content and sulfur content first decrease sharply and then slowly decrease; the Gibbs free energy of yttrium-containing compounds decreases as the content of rare earth yttrium increases; the Gibbs free energy of Y2O2S is the most negative and the Gibbs free energy of Y2O3 is the largest. It is concluded from the thermodynamic calculation results that rare earth yttrium can be desulfurized and deoxidized, and the desulfurization tendency of yttrium is greater than the deoxidation tendency; Y2O3 is unstable and can be transformed into Y2O2S.
Stained Glass in Lingnan Historic Buildings and Its Application in Manchuria Windows
Authors: Yan Lina , Chen Yile
Published: April 2021

Stained glass has been extensively applied in Lingnan historic buildings, especially unique stained art glass windows which will be usually used at doors and windows needing large-area lighting for the purpose of ventilation and lighting, and they are called Manchuria windows. First of all, under the historical application background of stained glass in the Lingnan area, this study discussed the types of stained glass and the technological development in Guangzhou. Secondly, the fabrication process of glass etchings was generalized. Next, the application laws of stained glass in Manchuria windows of Lingnan historic buildings were explored. Finally, the basic combination modes of stained glass applied in Manchuria windows were obtained. These laws and modes can not only provide a reference for the repair of Lingnan historic buildings but also constitute an enlightenment on the windowing form and artistic creation of modern buildings.
Preparation of carbon/silica composite aerogel and application of fire insulation
Authors: Fang Dehao , He Yan
Published: April 2021

In order to improve the disadvantages of aerogel brittleness and easy structural destruction during drying, carbon/silica dual network aerogel composites were constructed by copolymerizing carboxylated carbon nanotubes and tetraethyl orthosilicate decomposition products on chitosan templates. The composites were characterized by microscopic morphology and structural properties. The results show that the bulk carbon/silica aerogel composites can be prepared by freeze-drying through the reinforcement of chitosan templates and carbon nanotubes. The N2 adsorption and desorption curves of the composites show a type IV curve. The thermal conductivity of the material is only 0.0375 W/(m*K) at higher temperatures, which does not change much compared to that at room temperature (0.0312 W/(m*K)).
Experimental study on microstructure of overcurrent fault of copper conductor
Authors: Cai Zhouquan , Shi Lin
Published: April 2021

This study aims to more accurately identify the microstructure characteristics of copper wire when overcurrent fault occurs, and further improve the accuracy of electrical fire investigation. In this paper, the overcurrent fault of copper conductor under 4-7 times rated current is simulated. The difference of metallographic structure under different current is analyzed by metallographic microscope. Image-Pro-Plus software is used to measure grain perimeter, and the quantitative criterion and change rule of metallographic structure are studied. The experimental results show that with the increase of current, the diameter and area of the grains tend to increase. When Ie=128A, the grains are mainly slender dendritic and columnar, accompanied by a small amount of cellular crystal distribution. The grain directions are different, and the boundary between grains is large; when Ie=160A, the grains continue to grow, the number of dendritic crystals increases, and the grain boundary becomes fine; when Ie=192A, the grains are mainly columnar and cellular, with clear grain boundaries, obvious lattice and generally consistent grain directions; when Ie=224A, the dendritic grains decrease obviously, and the grain diameter and area have little change compared with 192A.
Modeling and simulation of the temperature field of selective laser sintering
Authors: He Qiyang , Ao Xiaohui , Xia Huanxiong , Liu Jianhua , Yang Chun , Ren Ce
Published: April 2021

Selective Laser Sintering (SLS) is a kind of powder-bed additive manufacturing technology, which can directly shape parts with complex geometry. The heat transfer process has an important influence on the forming quality of the SLS process. Computational methods are useful to study the heat transfer in the process since the temporal and spatial scale is extremely tiny. This paper presented a model, coupling the discrete element method and heat transfer equations, to calculate the powder-applying and heat-transfer phenomenon. Firstly, the discrete element method and the basic framework of the heat pipe model were introduced, and then the process of manufacturing a mini propeller blade by SLS was simulated.
Development of A High Stiffness Linear Compression Spring
Authors: Huang Jinfei , Zhang Hangbin , Lin Wanglin , Zhao Xinze
Published: April 2021

This paper summarizes the whole process of design, trial-manufacture, improvement and final design of the spring, which is the core part of the shock absorption device for the surface layer of synthetic materials in the standard GB 36246-2018 “Surface layer sports ground for primary and middle schools”. The successful development of this key part fills the blank of spring deformation parts in domestic testing industry, and can be used in other fields.
Optimization of Milling Cutting Parameters under Carbon Efficiency Target
Authors: Yin Ruixue , Wang Ze
Published: April 2021

In order to improve the energy efficiency of the CNC milling process and reduce the carbon emissions during the milling process, this paper presents a method for cutting parameters selection by considering both materials remove rate and carbon emissions. First, a metric called carbon emissions efficiency is proposed with consideration of the materials remove rate and carbon emissions. Second, the carbon emissions evaluation model for NC milling process is built based on the input-output flows. Third, an optimization model for the parameters used in a milling operation is built where the spindle speed and feed rate are taken into account as optimization variables. Constraints are proposed based on the machine tool performance parameters and the quality requirements of the workpiece. A genetic algorithm is employed to solve the optimization problem. A case is studied to validate the model.
Thermoelastic Damping in Fully Clamped Circular Plate Resonators Based on Nonlocal Thermoelasticity
Authors: Ge Xiao , Li Pu , Fang Yuming , Yang Longfei
Published: April 2021

Thermoelastic damping (TED) is the main source of energy dissipation in resonators. The modelling of TED is of great importance for the design of micro-electro-mechanical systems (MEMS) and the improvement of quality factor. Most of the previous TED models are based on classical continuum mechanics and Fourier heat conductive model. However, small-scale effects are widely found for structures at nano and sub-micron level and the classical theories cannot describe their size-dependent behaviors. Based on the nonlocal elasticity theory and the nonlocal heat conductive model, the thermoelastic coupled governing equations of a circular plate with out-of-plane vibration under the influence of nonlocal effect are derived in this paper. The influences of nonlocal thermoelasticity on TED in circular plates are discussed by numerical examples under different boundary conditions, frequencies, thicknesses and modes.
The Viscoelastic Fluid Flow in a Confusor
Authors: Kadyirov Aidar , Zaripov Rinat , Karaeva Julia , Vachagina Ekaterina
Published: April 2021

The planar flow of a viscoelastic fluid is studied in tapered channel (confusor) with different contraction rates (2:1, 4:1, 6:1). A polymer melt is considered as a specific liquid, rheological behaviour is described using the four mode Giesekus model. The effect of the contraction rate of a confusor on the axial velocity profiles and the components of normal and shear stresses is investigated. Approbation of numerical studies was carried out by means of the example of the planar flow of a viscoelastic fluid in a channel with abrupt contraction.
Retraction: Exploring the Response of Combined Urban Sewer System to the Implementation of Green Roof (IOP Conf. Ser.: Earth Environ. Sci.
178 012043)
Authors: Gao Yuqin , Wang Dongdong , Schmidt A , Tang Yun
Published: April 2021

IOP Publishing Limited ("IOPP") is retracting this paper following an investigation which has confirmed this work has significant overlap with a thesis written by another person, without permission or acknowledgement to the original authors. IOP Publishing Limited request any citations to this article be redirected to the original work [1].

IOPP have made multiple attempts to contact the author but has not received a response. The author is encouraged to contact jpconf@ioppublishing.org

[1] Yun Tang 2012 Exploring the response of urban storm sewer system to the implementation of green roofs Master's Thesis University of Illinois at Urbana-Champaign, USA

Retraction published: 28 April 2021
Research on the Early Warning Threshold of Slope Displacement Rate
Authors: WuJiangpeng  , YuJunping  , ZhuLiqing  , Suyang  , ZhangChengke
Published: April 2021

Slope is affected by internal structure and external natural and human factors, and the evolution process is quite complicated, which makes it difficult to determine the early warning indicators of slope instability. In view of the complexity of slope deformation, this paper introduces similarity theory, collects and sorts out related engineering data and landslide data of slid slopes in the past, uses engineering analogy to propose a displacement rate warning threshold method, and verifies the effectiveness of this method with engineering examples.
Numerical analysis of dynamic characteristics of sludge-type slag landfill landslide
Authors: Lei Wang , Xiaoguang Cai , Ping Li , Yuna Qi
Published: April 2021

The Artificial landfill landslide in Guangming District, Shenzhen, which occurred on December 20, 2015, showed the same characteristics as mudflow after sliding, which had long sliding movement distance and large coverage area, and caused serious casualties and property losses. Therefore, research on the dynamic characteristics of artificial accumulation landslide is of great significance for landfill slope hazard assessment and prevention in urban construction. On the basis of detailed collection of landslide investigation data and field investigation, the motion of the landslide was simulated with the friction rheological model by the software DAN-W in this paper, in order to obtain the characteristic parameters of landslide movement. The results showed that, the maximum movement distance was 1,112 meters and a running time of 105s simulated by friction model. The maximum front velocity was 22.5m/s and occurred at a horizontal distance of 632 meters. The horizontal length of the accumulation mass was 580 meters and the average thickness was about 8.2m. The numerical simulation results are basically consistent with the field survey results. The simulation model and the motion characteristic parameters of the muck can be used as reference for the prevention and control design of slope of similar muck field.
Research on UAV Path Planning Algorithms
Authors: Wang Hao , Pan Weijun
Published: April 2021

UAVs have received extensive attention and research due to their superior mobility and flexibility, and they replace manned aircraft to perform tasks in some specific complex environments. In order to deal with the complex and changeable environment and various obstacles, it is necessary to use appropriate algorithms to plan the UAV path. This paper divides the existing UAV path planning algorithm research into three categories: traditional algorithm, intelligent algorithm and fusion algorithm. The basic principles, advantages and disadvantages of various algorithms are analyzed, and the future research and development are prospected based on the actual operation of UAV.
Public spaces of small historical towns
Authors: Krasheninnikov A V , Lebedev A A , Ivanova A A
Published: April 2021

To improve the quality of the urban environment, it is important to analyze the patterns of placement of public spaces. The results obtained will help to create the framework of public spaces more correctly, including new and existing places of attraction for people.
Urban planning and development of the area of Peschanye streets in Moscow: past, present and future
Authors: Maximova O I
Published: April 2021

The paper analyses basic approaches which should be implemented for transformation of urban environment to preserve urban heritage values. For case study was chosen Peschanye streets district (Moscow, Russia) as an integral element of the urban environment, as a historical and cultural, experimental city district and as a potentially emergency development site. The article discusses the heritage and cultural landscape-based approach for urban development where the conservation and development are potential partners, affects principles and processes and all together can create increased value for city and citizens.
Legal aspects of financing the development of a modern urban environment
Authors: Gorlova E N
Published: April 2021

The formation of a comfortable urban environment is one of the important challenges of public authorities and is implemented at the level of the constituent entities of the Russian Federation and municipalities. The development of modern cities poses many challenges for their administration, most of which are solved by state or municipal funding (co-funding). In the context of budget deficit at the regional and local levels, it is necessary to develop a methodology for the distribution of costs on improvement and other social needs.
Rivers, urban community and production of space
Authors: Rudoy R O , Zayets D A
Published: April 2021

The article studies the characteristics of a river in a city as a special type of an urban environment object, which defines a special type of spatiality. The access of the community to the production of city space through the production of river space is considered. The authors analyze whether the river can be a catalytic space for the urban community, which allows it to better cope with this role than other spaces do, and how the potential of rivers can be used in the production of urban space.
Resource management of political influence during crisis
Authors: Polosin A V , Chikharev I A
Published: April 2021

The article discusses approaches to crisis management based on the resources of political influence. The research is based on a dynamic model of resources of political influence, which includes the main resources of trust and competence, which, in turn, allow mobilizing and optimal distributing of material resources. The importance of resources of political influence in various aspects and at various stages of crisis management and anti-crisis communications has been demonstrated. On the basis of a systematic approach to the development of social systems, the features of the processes of substitution and compensation of resources in the conditions of crisis dynamics of the system are analyzed. Possibilities of concentration of power resources in crisis conditions are considered. The perspective of modern approaches to public management based on information, data and knowledge management and based on social intelligence is revealed.

The study was conducted on the material of individual nuclear cities during the first wave of the spread of the new coronavirus infection.
Functions of the capital city in the political and territorial structure of the state
Authors: Okunev I Y
Published: April 2021

The capital is one of the backbone institutions in the political and administrative structure of the state. This is not only the location of the central authorities, the center for managing political processes in the country, but also the most important political institution that forms, reproduces and transforms its statehood, primarily influencing the political-territorial structure, the system of relations between “center-regions” and the regional state policy. This understanding of the capital city raises the question of why does the political and administrative structure of the state involve the allocation of a capital city, i.e. in other words, the inevitable division of the country into the center and regions, the formation of potentially conflicting social groups: residents of the center and residents of the periphery? And another question arising is what functions does such a division perform and how does it affect the nature of political processes in the state as a whole?
Management of the metropolises in Europe. Concepts, planning and trends
Authors: Maximova O I
Published: April 2021

The paper analyses concepts, planning and trends in European spatial planning network on the example of Rome (Italy), Berlin-Brandenburg (Germany) and Kristiansand (Norway) in order to formulate basic model for managerial innovations and conceptual framework consisting of key managerial innovations and approaches for spatial development of the metropolises. The article discusses the integrated diversity concept, the role of local actors in spatial development, spatial approach and spatially oriented policies, initiatives in strategic spatial planning and in regional development, innovative creative forces and regional identity.
Digitalisation of tax administration in the context of the development of high-tech municipalities
Authors: Moshkova D M
Published: April 2021

The priority direction of the development of the modern Russian economy is its digitalization, which necessitates the introduction of high technologies and innovative products in various areas of management and production. It should be noted that the process of tax administration is distinguished by a high level of application of digital technologies for calculating and paying taxes. The article studies the advantages and disadvantages of using digital technologies in the process of tax administration, including their application by territorial tax authorities in the constituent entities of the Russian Federation and municipalities. The analysis of specific measures for the implementation of high technologies in the field of taxation (personal account of the taxpayer, ACS “VAT-2”, “My Tax”) was performed and the prospects for improving the quality and efficiency of tax administration in the Russian Federation at the regional and local levels were identified.
Wettability improvement of carbon nanotube for supercapacitor electrode
Authors: Devianto H , Luthfiana N , Widiatmoko P , Nurdin I , Prakoso T
Published: April 2021

Carbon Nanotube (CNT) has outstanding properties such as electrical conductivity, specific surface area, charge transport capability, mesoporosity, and very high electrolyte accessibility. Based on these properties, CNTs are very suitable to be used as high-performance supercapacitor electrodes which can be seen from the capacitance. One of the factors that can lead to increase capacitance is the high interface interaction between CNT and the electrolyte. The interface interaction of CNT and electrolyte can be improved by increasing the CNT wettability using hydrophilization. CNT is synthesized by pyrolysis with Palm Oil Mill Effluent (POME) as the main raw material. In this study, hydrophilization was carried out using chemical activation HNO3 with various concentrations and activation times (1M for 1, 3, 6 hours, and 13M for 1 hour). The results of CNT structure were characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscope (TEM), and X-Ray Diffraction (XRD), as well as electrochemically characterized using cyclic voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS) dan galvanostatic charge-discharge (GCD), as supported data to evaluate which concentration and activation time with the highest efficiency to improve CNT performance as a supercapacitor. Based on CV characterization, the capacitance of CNT before hydrophilization, and after hydrophilization using HNO3 (1M for 1 hour, 3 hours, 6 hours, and 13M for 1 hour) were 10 F/g, 13.30 F/g, 14.28 F/g, 26.95 F/g and 24.5 F/g respectively. When CNT hydrophilized at 13M for 1 hour, capacitance decreased. Due to surface damage of CNT, therefore the performance of the supercapacitor decreased. This was supported by the results of the GCD characterization, where some charges could not completely release.
Cultivation of ‘Botryococcus Braunii’ Microalgae for Hydrocarbons Production and CO2 Bio-fixation
Authors: Dewi R G , Srikaton D , Sitorus S , Sevie G N , Bunga P , Permata S
Published: April 2021

CO2 fixation for climate change mitigation actions through photosynthesis can be carried out by growing intensively managed microalgae. The capability of microalgae in the CO2 fixation is favourable compare to trees or crops, yielding three to five times more biomass per land area than typical plants. Another interesting feature of microalgae is microalgal farms can use arid, semi-arid land or highly saline water, which is practically not suitable for agriculture and other biomass production activities. In addition, algae biomass contains fibre, fatty acid, lipid, protein, polysaccharide, and hydrocarbon. These materials could be extracted for biofuels or biochemicals. Biofuels derived from microalgae are environmentally friendly and carbon neutral. However, microalgal farming seen only for producing biomass as sources of fuels and chemicals probably uneconomical. The yields of microalgal farm to produce fuels/chemicals are also low. Therefore, microalgal farm with the objective of solely producing fuels/chemicals is economically unfeasible. If it is designed for CO2 mitigation measures and all at once for fuels/chemicals production, such endeavour could be economically justifiable. This paper presents results of a research on microalgae cultivation for producing biomass and hydrocarbons for biofuels that simultaneously fixing the CO2 emissions from coal power plant effluent through photosynthesis process, which also for the implementation of circular economy concepts. A strain of ‘Botryococcus Braunii’ microalgae, which known can produce high hydrocarbons and lipids throughout its growth period has been used. The research identified and evaluated the effect of cultivation medium and CO2 concentration to the growth rate, biomass production, lipid and hydrocarbon content and type. The microalgae were cultivated in bioreactor supported with airlift system for supplying CO2/air and for mixing process. Results of the research show that modified Chu13 (MChu13) is appropriate cultivation medium for the growth, hydrocarbon/lipid production, and CO2 fixation from B. braunii. The magnitude of biomass production in MChu13 is 0.145 g/L.9days, while in modified BG11 is 0,118 g/L.9days, Bold Bassal Medium (BBM) is 0.09 g/L.9days, and Bristol is 0.023 g/L.9days. This biomass production rate is in lined with the CO2 fixation rate. In MChu13 the dry weight of B.brauni is 0.268 g/L.7days while in Bristol only 0.229 g/L.7days.
Study on Indonesian plastic marine debris based on river survey
Authors: Abidin A Z , Steven S
Published: April 2021

In response to Jambeck’s claim on Indonesian plastic marine debris, some academicians, scientists, as well as associations such as The Indonesian Olefin and Plastic Industry Association (INAPLAS), Indonesian Plastic Recycle Association (ADUPI), and Indonesian Plastic Recycle Industry Association (APDUPI) conducted a deeper plastic balance examination to clarify and enlight the Indonesian plastic marine debris amount. This study continued the previous work, which employed the river survey method to conduct a more accurate calculation in the actual condition. From the river survey results, Indonesian plastic marine debris amount is about 0.038 MT/y and it will reduce to 0.004 MT/y if the trash trap is strictly-applied. This result is not much different compare to the seashore approach but again also clarifies that Indonesia is not the second-largest contributor country for plastic marine debris. Moreover, asides from conserving the marine and river environments, installing a trash trap on the river could increase local people’s income at once.
Energy and Exergy Analysis on the Rotary Kiln Unit of RKC-2 PT. Semen Gresik – Tuban Plant
Authors: Hayati Nasution Mala , Rasyid Syahputra Irwan , Rahman Darul
Published: April 2021

Cement industry is an industry that intensively uses energy in the process. One of the main units in a cement plant that consumes the most energy is the rotary kiln. Rotary kiln is used for calcination process of cement raw material into clinker. It operates at 900-1450°C. It obtains energy from coal combustion process. Energy conservation in rotary kiln can be used to optimize production costs. Energy conservation can be carried out through energy identification. One method of energy identification is through energy and exergy analysis. In this study, energy and exergy analysis was carried out at the rotary kiln unit of RKC-2 PT. Semen Gresik - Tuban Plant. The analysis was carried out based on the calculation of the mass balance, energy balance, enthalpy balance, entropy balance and exergy balance. These calculations are used to obtain energy efficiency, exergy efficiency and irreversibility. Based on the research results, the energy efficiency, exergy efficiency, and irreversibility were 69,2%; 50,48% and 49,52% respectively.
Separation of Potassium from The Model Solution
Authors: Puspita Ratna , Susanto Herri
Published: April 2021

Potassium content in biomass ashes, especially empty fruit bunches was quite high and had not been utilized maximally. This research dealt with the development of a technique for recovering potassium salt from a solution of ash extraction. Experiments were carried out usung a solution model containing KCl, NaCl, MgCl2, and CaCl2 with concentrations of 164.19, 8.39, 7.44, dan 39.60 mg/L respectively. Results of a preliminary experiment indicated that the solubilities of KCl and NaCl were reversed: 280.4 and 280.4 (g/L in water) to 6.9 and 14.2 (g/L in absolute ethanol), while the solubilities of MgCl2 and CaCl2 were still high (68.7 and 383.5 g/L in ethanol). Using these values of solubility, a combined evaporation and adding ethanol was trialed firstly to increase the precipitation of KCl. Evaporation of KCl solution 164.19 g/L until an evaporation leves of 15% did not give any precipitation yet, while adding ethanol to the remaining solution (at solution ratios of 4/1 and 3/2 ethanol) yielded precipitations with the potassium recoveries of 60% and 48% respectively. At an evaporation level of 30%, the evaporation yielded a 5% potassium recovery, while the combined technique gave 60% and 50% recoveries for adding ethanol with ratios of 4/1 and 3/2 respectively. The application of the combined technique on the mixed salts solution was modified slightly. The precipitate from the evaporation (containing KCl and NaCl) was redissolved into water and followed by adding ethanol to precipitate only KCl. Thus, two precipitates were finally obtained: (i) precipitate from adding ethanol to filtrate of evaporation, and (ii) precipitate from dissolving precipitate from evaporation. At an evaporation level of 30%, the evaporation only gave a precipitate recovery of about 10%, while the application of combined technique gave bout 80% and 60% recoveries by adding ethanol with ratios of 4/1 and 3/2 respectively. Hopefully this technique could separate KCl from its mixture with NaCl, MgCl2, and CaCl2.
Natural Gas Network Design using Superstructure Method in East Java Indonesia
Authors: Panca Anugraha Rendra , Renanto  , Juwari
Published: April 2021

East Java is one of the provinces in Indonesia which has total natural gas reserves of 4.66 trillion standard cubic feet (TSCF) spread across several locations. Natural gas in this province is used by a variety of consumers, such as petrochemical industries, power plants, industrial fuel, transportation and household needs. However, there are obstacles in the utilization of natural gas due to differences in operating time and differences capacity between suppliers and consumers. Therefore, to optimize the utilization of natural gas in East Java, a natural gas network design is required which is considering the operating time and the capacity of suppliers (source point) and consumers (sinks point). In this study, a natural gas network design of East Java area was developed by modelling superstructure methods which consider the operating time and capacity. The superstructure natural gas network model developed in this study was optimized using GAMS software. From 5 source points and 6 sink points, an optimum natural gas network design has been obtained with a total gas distribution of 4832.8 billon standard cubic feet (BSCF) in a period of 30 years. Due to mismatch of operating time, it is also known that the amount of excess gas supply from this area (export gas) is 1364.1 BSCF and the demand for gas supply from other areas (import gas) is 1105.7 BSCF. With this superstructure method, it is possible to know the optimum network configuration and the natural gas balance in an area which has different operating time, flowrate and capacity between sources and sinks.
Synthesis of Maleic-Modified Rosin Ester from Pine Rosin
Authors: Prakoso Tirto , Kumalasari Ihda , Jiwandaru Bramantha , Hernas Soerawidjaja Tatang , Mufti Azis Muhammad , Indarto Antonius
Published: April 2021

Rosin is the major component of Pine sap that has a composition of up to 90%. Rosin is an organic compound that consists of diterpene tricyclic compounds with carboxyl functional group. The presence of this functional group makes rosin becoming acidic and corrosive. Furthermore, rosin also has double bonds that are prone to oxidation when exposed to air. To improve the weaknesses, modifications shall be done. Esterification reaction can be done through transforming into a more stable functional group, ie. ester, while Diels-Alder reaction will saturate the double bonds into more stable cyclic compounds. The results indicate that synthesizing maleic modified rosin ester could improve the properties of pine rosin. Esterification was done using a ratio of glycerol to rosin of 1:3 mol. Esterification was done for 6 hours at 250°C at room and vacuum pressure. The Diels-Alder reaction was done using maleic anhydride at 1:1 stoichiometric ratio to rosin, reacted at 150°C for 1 hour at vacuum condition.
Finding the optimum concentration of silicon carbide and graphite particles on the tensile strength, hardness and wear properties of aluminium matrix composites by RSM approach
Authors: M Bakkiyaraj
Published: April 2021

The present investigation aims to determine the optimum concentration of SiC and graphite reinforcements in AA7075 matrix based hybrid composites to obtain better tensile strength, hardness, coefficient of friction and wear rate using RSM. Reinforcement particles of SiC varied from 5% to 15% whereas graphite particles varied from 3% to 7% in the AA7075 matrix. A central composite design of RSM was adopted to develop the numerical model, and the statistical data were derived using analysis variances to evaluate adequacy of the model. Meanwhile, the conformity test has been conducted to validate the developed numerical model. Following this, the output responses of the optimized conditions were taken into account for the characterization of microstructure, fractured surface, and worn surface characters using optical microscope, and scanning electron microscope. The effect of SiC and graphite particles on the tensile strength, hardness, and wear properties and its result were reported in detail along with comparison of previous researchers.
Spatially multiplexed interferometric microscopy: principles and applications to biomedical imaging
Authors: Picazo-Bueno José Ángel , Trusiak Maciej , García Javier , Micó Vicente
Published: April 2021

Digital holographic microscopy (DHM) applied to quantitative phase imaging (QPI) has been successfully demonstrated as a powerful label-free method to analyse the optical properties of cells. Spatially multiplexed interferometric microscopy (SMIM) is a DHM technique that implements a common-path interferometric layout in the embodiment of a standard microscope to achieve QPI. More concretely, SMIM introduces three minimal modifications: (a) replaces the broadband illumination of the microscope by a coherent or partially coherent light source, (b) divides the input plane into two or three regions for transmission in parallel of both imaging and reference beams, and (c) includes a one-dimensional (1D) diffraction grating or a beam splitter cube for holographic recording. Hence, SMIM is a cost-effective, extremely simple, and highly stable manner of converting a standard bright field microscope into a holographic one. The goal of this contribution is to present the SMIM approaches implemented using a 1D diffraction grating, and highlight vast range of capabilities for biomedical imaging including super-resolved, reflective, transflective, noise-reduced and single-shot slightly off-axis amplitude and phase imaging.
Hardware realization of the multiply and accumulate operation on radio-frequency signals with magnetic tunnel junctions
Authors: Leroux Nathan , Mizrahi Alice , Marković Danijela , Sanz-Hernández Dédalo , Trastoy Juan , Bortolotti Paolo , Martins Leandro , Jenkins Alex , Ferreira Ricardo , Grollier Julie
Published: April 2021

Artificial neural networks are a valuable tool for radio-frequency (RF) signal classification in many applications, but the digitization of analog signals and the use of general purpose hardware non-optimized for training make the process slow and energetically costly. Recent theoretical work has proposed to use nano-devices called magnetic tunnel junctions, which exhibit intrinsic RF dynamics, to implement in hardware the multiply and accumulate (MAC) operation—a key building block of neural networks—directly using analog RF signals. In this article, we experimentally demonstrate that a magnetic tunnel junction can perform a multiplication of RF powers, with tunable positive and negative synaptic weights. Using two magnetic tunnel junctions connected in series, we demonstrate the MAC operation and use it for classification of RF signals. These results open a path to embedded systems capable of analyzing RF signals with neural networks directly after the antenna, at low power cost and high speed.
SET levels contribute to cohesion fatigue
Authors: Yang Lu , Zhang Qian , Niu Tianhua , Liu Hong
Published: April 2021

Cancer cells often exhibit weak centromeric cohesion, but the molecular mechanisms are little known. Here we show that SET overexpression contributes to impaired centromeric cohesion in cancer cells and illustrate a misregulated SET-Sgo1 pathway as one of the underlying mechanisms.
Learning to Imagine
Authors: Kind Amy
Published: April 2021

Underlying much current work in philosophy of imagination is the assumption that imagination is a skill. This assumption seems to entail not only that facility with imagining will vary from one person to another, but also that people can improve their own imaginative capacities and learn to be better imaginers. This paper takes up this issue. After showing why this is properly understood as a philosophical question, I discuss what it means to say that one imagining is better than another and then discuss the kinds of imagination training and techniques that might be employed in an effort to get better at imagining. The discussion of these techniques draws insight from consideration of other skills-based activities, as well as from consideration of the creation of art and our engagement with literature and poetry. Over the course of this discussion, we also gain further insight into the nature of imagination.
In situradiation explains the frequency of dioecious palms on islands
Authors: Cássia-Silva Cibele , Freitas Cíntia G , Jardim Lucas , Bacon Christine D , Collevatti Rosane G
Published: April 2021

Background and Aims

Dioecy has evolved up to 5000 times in angiosperms, despite the potentially high intrinsic costs to unisexuality. Dioecy prevents inbreeding, which is especially relevant on isolated islands when gene pools are small. Dioecy is also associated with certain dispersal traits, such as fruit size and type. However, the influence of dioecy on other life history traits and island distribution remains poorly understood. Here, we test the effect of dioecy on palm (Arecaceae) speciation rates, fruit size and frequency on islands.

Methods

We used phylogenetic comparative methods to estimate the ancestral state of the sexual system and its impact on speciation rates and fruit size. Frequency of sexual systems, effect of insularity on the probability of being dioecious, and phylogenetic clustering of island dioecious vs. mainland species were inferred. Lastly, we determined the interplay of insularity and sexual system on speciation rates.

Key Results

Palms repeatedly evolved different sexual systems (dioecy, monoecy and polygamy) from a hermaphrodite origin. Differences in speciation rates and fruit size among the different sexual systems were not identified. An effect of islands on the probability of the palms being dioecious was also not found. However, we found a high frequency and phylogenetic clustering of dioecious palms on islands, which were not correlated with higher speciation rates.

Conclusions

The high frequency and phylogenetic clustering may be the result of in situ radiation and suggest an ‘island effect’ for dioecious palms, which was not explained by differential speciation rates. This island effect also cannot be attributed to long-distance dispersal due to the lack of fruit size difference among sexual systems, and particularly because palm dispersal to islands is highly constrained by the interaction between the sizes of fruit and frugivores. Taken together, we suggest that trait flexibility in sexual system evolution and the in situ radiation of dioecious lineages are the underlying causes of the outstanding distribution of palms on islands.
Evaluating disease similarity based on gene network reconstruction and representation
Authors: Li Yang , Keqi Wang , Wang Guohua
Published: April 2021

Motivation

Quantifying the associations between diseases is of great significance in increasing our understanding of disease biology, improving disease diagnosis, re-positioning and developing drugs. Therefore, in recent years, the research of disease similarity has received a lot of attention in the field of bioinformatics. Previous work has shown that the combination of the ontology (such as disease ontology and gene ontology) and disease–gene interactions are worthy to be regarded to elucidate diseases and disease associations. However, most of them are either based on the overlap between disease-related gene sets or distance within the ontology’s hierarchy. The diseases in these methods are represented by discrete or sparse feature vectors, which cannot grasp the deep semantic information of diseases. Recently, deep representation learning has been widely studied and gradually applied to various fields of bioinformatics. Based on the hypothesis that disease representation depends on its related gene representations, we propose a disease representation model using two most representative gene resources HumanNet and Gene Ontology to construct a new gene network and learn gene (disease) representations. The similarity between two diseases is computed by the cosine similarity of their corresponding representations.

Results

We propose a novel approach to compute disease similarity, which integrates two important factors disease-related genes and gene ontology hierarchy to learn disease representation based on deep representation learning. Under the same experimental settings, the AUC value of our method is 0.8074, which improves the most competitive baseline method by 10.1%. The quantitative and qualitative experimental results show that our model can learn effective disease representations and improve the accuracy of disease similarity computation significantly.

Availability and implementation

The research shows that this method has certain applicability in the prediction of gene-related diseases, the migration of disease treatment methods, drug development and so on.

Supplementary information

Supplementary data are available at Bioinformatics online.