bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of growth temperature on defect states throughout the bandgap of MOCVD-grown
β
-Ga2O3
Authors: Ghadi Hemant , McGlone Joe F. , Feng Zixuan , Bhuiyan A F M Anhar Uddin , Zhao Hongping , Arehart Aaron R. , Ringel Steven A.
Published: October 2020

The influence of growth temperature on the distribution (concentrations and energy levels) of individual defect states in metal organic chemical vapor deposition-grown, Si-doped β-Ga2O3 is investigated. A combination of deep level thermal transient/optical spectroscopies and admittance spectroscopy (AS) was used to quantitatively monitor the evolution of trap states throughout the ∼4.8 eV bandgap. States are observed at EC-0.12 eV by AS; at EC-0.4 eV by deep level transient spectroscopy; and at EC-1.2 eV, EC-2.0 eV, and EC-4.4 eV by deep level optical spectroscopy, and showed different dependencies on growth temperatures ranging from 800 °C to 920 °C. The EC-0.4 eV and EC-4.4 eV states both displayed a strong reduction in its concentration with increasing growth temperature, whereas no consistent trends were seen for the states at EC-1.2 eV and 2.0 eV over the temperature range studied. In contrast, the concentration of the EC-0.12 eV trap monotonically increased over the same range of increasing growth temperature, which tracked a slight, monotonic increase in overall Si concentration measured by secondary ion mass spectroscopy with growth temperature. The opposing trends in concentrations for some of these states shifted the dominant deep level in the bandgap from the EC-4.4 eV state at the lowest growth temperature explored here to the EC-0.12 eV state at the highest growth temperature. The shifting dominance of various bandgap states can have important ramifications on β-Ga2O3 device behavior, and the different trends for these deep levels cannot only guide further growth optimization but also advance the identification of their physical sources.
Geometric metasurface for multiplexing terahertz plasmonic vortices
Authors: Zang XiaoFei , Li Zhen , Zhu Yang , Xu Jiong , Xie JingYa , Chen Lin , Balakin Alexei V. , Shkurinov Alexander P. , Zhu YiMing , Zhuang SongLin
Published: October 2020

Surface plasmon polaritons carrying orbital angular momentum (OAM), namely, as plasmonic vortices, have attracted considerable attention in optical trapping, quantum information processing, and communications. The previous studies of near-field OAM are limited to generate only one single plasmonic vortex, which inevitably degrades further on-chip applications. Geometric metasurfaces, two-dimensional counterpart of metamaterials, enable the unprecedented capability in manipulating the phase, polarization, and amplitude of electromagnetic waves, providing a flexible platform in controlling plasmonic vortices. Here, we propose and experimentally demonstrate an approach to realize the multiplexing of terahertz (THz) plasmonic vortices based on geometric metasurfaces. Under the illumination of circularly polarized THz waves, multiple plasmonic vortices with identical topological charges are generated at the metal/air interface. Furthermore, the conversion from spin angular momentum to multiple plasmonic OAM, i.e., multiple plasmonic vortices with different topological charges, is also demonstrated. Geometric metasurfaces consisting of paired air-slits with different in-plane orientations are designed to demonstrate these characteristics. Our proposed approach may open an avenue for on-chip applications with increasing information capacity.
Streamlining the graphical forecast process
Authors: Just Andrew , Foley Michael
Published: October 2020

The national meteorological services of Australia and the United States have followed similar paths in modernising production of their public weather forecasts during the past two decades. Both have adopted grid-based forecasts constructed by forecasters using a graphical forecast process. As gridded forecasting has matured, both have worked to achieve a more streamlined and standardised forecast process, so as to free up forecaster time for other activities such as decision support and a focus on high-impact weather, while increasing consistency in the gridded forecasts. We will describe the paths followed in Australia and the U.S., specifically in the U.S. National Weather Service Central Region, towards a more streamlined graphical forecast process. Although the journeys have been rather different, they have converged on similar solutions. A variety of lessons have been learned regarding how to achieve effective change in weather forecast production, through grassroots engagement and management support.
It is unclear how important CRISPR-Cas systems are for protecting natural populations of bacteria against infections by mobile genetic elements
Authors: Westra Edze R. , Levin Bruce R.
Published: October 2020

Articles on CRISPR commonly open with some variant of the phrase “these short palindromic repeats and their associated endonucleases (Cas) are an adaptive immune system that exists to protect bacteria and archaea from viruses and infections with other mobile genetic elements.” There is an abundance of genomic data consistent with the hypothesis that CRISPR plays this role in natural populations of bacteria and archaea, and experimental demonstrations with a few species of bacteria and their phage and plasmids show that CRISPR-Cas systems can play this role in vitro. Not at all clear are the ubiquity, magnitude, and nature of the contribution of CRISPR-Cas systems to the ecology and evolution of natural populations of microbes and the strength of selection mediated by different types of phage and plasmids to the evolution and maintenance of CRISPR-Cas systems. In this perspective, with the aid of heuristic mathematical–computer simulation models, we explore the a priori conditions under which exposure to lytic and temperate phage and conjugative plasmids will select for and maintain CRISPR-Cas systems in populations of bacteria and archaea. We review the existing literature addressing these ecological and evolutionary questions and highlight the experimental and other evidence needed to fully understand the conditions responsible for the evolution and maintenance of CRISPR-Cas systems and the contribution of these systems to the ecology and evolution of bacteria, archaea, and the mobile genetic elements that infect them.
Differential functional connectivity underlying asymmetric reward-related activity in human and nonhuman primates
Authors: Lopez-Persem Alizée , Roumazeilles Léa , Folloni Davide , Marche Kévin , Fouragnan Elsa F. , Khalighinejad Nima , Rushworth Matthew F. S. , Sallet Jérôme
Published: October 2020

Significance

Lateralization of functions in the brain has been demonstrated in many different cognitive processes. It is supposed to increase processing abilities by reducing bilateral redundancy. Yet lateralization of reward processing, despite extremely common asymmetrical findings, has received little attention. Our neuroimaging study shows a functional lateralization of the response to reward in the lateral part of the orbitofrontal cortex (OFC), together with an asymmetric functional connectivity pattern. This particular feature was identified not only in humans but also in nonhuman primates. Our findings challenge the classical view of the OFC as a symmetrical brain region. They are urging the need for considering the specific contribution of the left and right OFC when investigating reward-related signals.
A CRISPR-Cas9 screen identifies mitochondrial translation as an essential process in latent KSHV infection of human endothelial cells
Authors: Holmes Daniel L. , Vogt Daniel T. , Lagunoff Michael
Published: October 2020

Significance

Kaposi’s sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi’s sarcoma, one of the most common neoplasms in sub-Saharan Africa. There is no direct treatment for the latent state of the virus in tumors. Therefore, we sought to identify host cell targets essential to support proliferation and survival of cells latently infected with KSHV. A genome-wide CRISPR-Cas9 knockout screen to test the requirement of all human genes during KSHV latency identified host factors involved in mitochondrial translation as necessary for proliferation of latently infected endothelial cells. Antibiotics targeting bacterial ribosomes are able to selectively inhibit the proliferation of KSHV latently infected cells. Our findings provide insights into the essential function of mitochondria during latent KSHV infection.
The effect of sport training on otolith function in adults with profound sensorineural hearing loss
Authors: Zarrinkoob Homa , Bayat Arash , Kaka Nasim
Published: October 2020

Objectives

It seems that regular physical activity leading to favourable alternations in the bodily system, including improved muscle mass, as well as better postural control. This study aims to assess the effect of strenuous training program on balance function in deaf adults.

Methods

During a cross-sectional design, 50 deaf patients and 22 healthy adults (with no history of vertigo and hearing loss) were included. Deaf patients were also classified as “non-athletes” and “athletes” groups. The vestibular (Otolith) function testing was carried out using the cervical vestibular-evoked myogenic potential (cVEMP) and ocular vestibular-evoked myogenic potential (oVEMP).

Results

The mean p13 latency and p13-n23 amplitude of cVEMPs in the control group were significantly shorter, and larger than the deaf groups, respectively. Furthermore, the mean p13-latency in “athletes deaf” group was significantly earlier than the “non-athletes deaf” group. The p1 and n1 oVEMP peak latencies were significantly prolonged in deaf patients than the controls. The comparison of the asymmetry ratio between the control and deaf groups was significant only for the cVEMP response.

Conclusion

Our results indicated that otolithic dysfunction is a common and hidden problem in the deaf population. Strenuous sport training in adults can be considered as an effective therapeutic intervention to stimulate vestibular function in deaf patients.
BAFFR controls early memory B cell responses but is dispensable for germinal center function
Authors: Lau Angelica W.Y. , Turner Vivian M. , Bourne Katherine , Hermes Jana R. , Chan Tyani D. , Brink Robert
Published: October 2020

The TNF superfamily ligand BAFF maintains the survival of naive B cells by signaling through its surface receptor, BAFFR. Activated B cells maintain expression of BAFFR after they differentiate into germinal center (GC) or memory B cells (MBCs). However, the functions of BAFFR in these antigen-experienced B cell populations remain unclear. Here, we show that B cell–intrinsic BAFFR does not play a significant role in the survival or function of GC B cells or in the generation of the somatically mutated MBCs derived from them. Instead, BAFF/BAFFR signaling was required to generate the unmutated, GC-independent MBCs that differentiate directly from activated B cell blasts early in the response. Furthermore, amplification of BAFFR signaling in responding B cells did not affect GCs or the generation of GC-derived MBCs but greatly expanded the GC-independent MBC response. Although BAFF/BAFFR signaling specifically controlled the formation of the GC-independent MBC response, both types of MBCs required input from this pathway for optimal long-term survival.
Automated method for measuring the energy gap of p–n junction semiconductor diodes with the temperature–voltage method
Authors: Klonkratog Bhanupol , Somdock Nuttakrit , Damrongsak Pattareeya
Published: October 2020

An automated system for measuring the energy gap E
g of a p–n junction semiconductor diodes was presented in this study. The system, based on temperature–voltage (T–V) measurement, was designed and developed as a teaching tool to support teaching for undergraduate students. The energy gap of diodes was measured by varying the diode temperature from 273 to 343 K and by measuring the voltage drop across the diode while the bias current of diodes was kept constant at a specific value. In the proposed system, an Arduino UNO R3 microcontroller was employed to automatically acquire the temperature and voltage drop across the diode. T–V data were plotted, and then the slope and intercept were used to calculate the energy gap by a simplified diode equation. In this system, the temperature and voltage of the two diodes were measured simultaneously at different constant bias currents in the range of 10 μA–10 mA. The average E
g value of 1.22 eV obtained in this work is in good agreement with that reported in the literature.
Direct generation of a circularly polarized TE11 mode in a relativistic backward wave oscillator by loading anisotropic medium
Authors: Fan Zhiqiang , Song Zhimin , Wang Huihui , Cao Yibing , Wu Ping , Liu Dagang , Sun Jun
Published: October 2020

A relativistic backward wave oscillator (RBWO) for direct generation of a circularly polarized TE11 mode is proposed. Using a coaxially loaded anisotropic medium with an appropriate longitudinal conductivity, the TM01 mode is effectively suppressed and the TE11 mode successfully stimulated. A dual-resonant reflector is incorporated in the RBWO to effectively reflect the TE11 mode. An isotropic absorber is deployed in front of the dual-resonant reflector to reduce the external Q factor of the TM01 mode and avoid undesired modulation. These distinctive features of the RBWO, allow a circularly polarized TE11 mode output to be obtained. Particle-in-cell simulations show that for a beam voltage of 1.12 MeV and a beam current of 12.3 kA, circularly polarized TE11 mode microwaves with power 3.9 GW and frequency 6.4 GHz can be obtained.
Updated analysis of jet quenching at RHIC and LHC within the light cone path integral approach
Authors: Zakharov B G
Published: October 2020

We present results of a detailed analysis of experimental data on the nuclear modification factor R
AA and the flow coefficient v
2 for light hadrons from RHIC for 0.2 TeV Au + Au collisions and from LHC for 2.76 and 5.02 TeV Pb + Pb, and 5.44 TeV Xe + Xe collisions. We perform calculations within the light-cone path integral (LCPI) approach to induced gluon emission. We use running α
s which is frozen at low momenta at some value

α

s

f
r

. We find that the RHIC data support somewhat larger value of

α

s

f
r

. For the χ
2 optimized values of

α

s

f
r

, the theoretical predictions are in reasonable agreement with data on R
AA and v
2. Calculations made for different formation times and life-times of the QGP show that jet quenching at the RHIC and LHC energies is only weakly sensitive to the initial and final stages of the QCD matter evolution.
Effect of TiO2 arrays on surface enhanced Raman scattering (SERS) performance for Ag/TiO2 substrates
Authors: Wang Yanfen , Ma Shuai , Yu Hai , Liu Yin , Gao Juan , Yang Lei , Zhang Miao , He Gang , Sun Zhaoqi
Published: October 2020

Ag/TiO2 nanostructure arrays were constructed on fluorine-doped tin oxide (FTO) via a controllable hydrothermal route and a magnetron sputtering method with a variety of TiO2 arrays decorated by Ag nanoparticles. Effects of different TiO2 arrays on the microstructure, composition, and optical properties of the samples were revealed. As surface enhanced Raman scattering (SERS) active substrates, we discussed the sensitivity and reproducibility of Ag/TiO2 nanostructure arrays for Rhodamine 6G (R6G) molecule detection. It was found that TiO2 nanosheet (TiO2(S)) array as a supporting made Ag nanoparticles have a uniform and continuous distribution, which achieved much higher SERS signals. The obtained Ag/TiO2(S) substrate had an improved enhancement factor of 4.31 × 105 compared with the other Ag/TiO2 nanostructure arrays of nanorods, nanotubes, and nanotrees. Furthermore, Ag/TiO2(S) active substrate showed good reproducibility with low relative standard deviation values. Such a remarkable SERS activity could be due to the synergistic effect of electromagnetic enhancement and charge transfer enhancement. Moreover, the TiO2(S) array with high-exposed {101} facets provided a large adhesion area and generated a strong interaction with external atoms, which would produce high-density ‘hot spots’ of SERS.
Controlled synthesis of Fe–Pt nanoalloys using atomic layer deposition
Authors: Ramachandran Ranjith K , Dendooven Jolien , Detavernier Christophe
Published: October 2020

We report the phase and size-controlled synthesis of Fe–Pt nanoalloys, prepared via a two-step synthesis procedure. The first step is the deposition of bilayers consisting of iron oxide and Pt films of desired thicknesses using atomic layer deposition, followed by a temperature-programmed reduction treatment of the film under H2/N2 atmosphere. This method enables the phase pure synthesis of all three Fe–Pt alloy phases, namely Fe3Pt, FePt, and FePt3, as revealed by in situ x-ray diffraction and x-ray fluorescence measurements. It is also demonstrated that by changing the total thickness of the bilayers while keeping the Pt/(Pt + Fe) atomic ratio constant, the size of the resulting bimetallic nanoparticles can be tuned, as confirmed by scanning electron microscopic measurements.
Mass dependent corrections of the orbital period of a planet
Authors: Feoli Antonio , Benedetto Elmo
Published: October 2020

This paper has a didactic aim. Indeed, starting from the well-known principle of free fall discovered by Galileo Galilei, we want to make some reflections that we consider useful for secondary school students. Being the acceleration invariant with respect to Galilei’s transformations, it is useful to underline that the free fall in a gravitational field is independent of the mass of the body that falls only if the attractive mass is an inertial frame. In general, the corrections to the motion of a test particle falling in a gravitational field due to its mass can be easily calculated avoiding misinterpretations of Galileo’s principle. Moreover, it may be useful to observe that, in the case of periodic motions, these corrections increase with time and would lead, over the centuries, to not negligible effects.
STEM shells
Authors: Hughes Stephen , Alkhazraji Sultan , Zhang Xiangyu , Nadarajah Helen , Goodwin Candice Michelle , Leisemann Scott , Evason Chris , Potter Darryl
Published: October 2020

Diffraction is an important phenomenon in physics. This paper describes using a scanning electron microscope (SEM) to produce cross-sectional images of iridescent seashells. When seashell cross-sections are viewed in a SEM, regular structure is seen. Seashells are a good example of a biocomposite material and good natural objects for introducing students to composite materials.
On Tsar Bomba—the most powerful nuclear weapon ever tested
Authors: Khan F A
Published: October 2020

Some
useful quantities like mass consumed, mass involved in
fusion, mass fissioned, energy density, temperature and pressure have been calculated for the most powerful nuclear weapon, Tsar Bomba. Besides, its calculated
efficiency is compared with seven other nuclear devices.
Persistent-mode operation and magnetization behavior of a solid-nitrogen-cooled MgB2 small-scale test coil towards a tabletop 1.5-T osteoporosis MRI
Authors: Choi Yoonhyuck , Park Dongkeun , Li Yi , Tanaka Hiromi , Lee Wooseung , Bascuñán Juan , Iwasa Yukikazu
Published: October 2020

We present results—cool-down, energization, and persistent-mode operation—of a solid-nitrogen (SN2)-cooled, magnesium diboride (MgB2) small-scale test coil. The test coil, immersed in a volume of solid nitrogen at 6 K, successfully operated in persistent-mode at 108 A for a period of 5 d. Although designated a ‘persistent-mode’ coil, its center field was measured to decay at a rate of <0.6 ppm h−1, which is still considered low enough to meet the temporal stability requirement of <0.1 ppm h−1, for most magnetic resonance imaging magnets. This decay rate translates to a calculated circuit resistance of <1.79 × 10–12 Ω, which is mainly from one MgB2-MgB2 joint in the circuit. However, when the coil temperature increased from 6 to 16 K, the field had dropped by 0.33%: we believe this was caused by the change of magnetization in the MgB2 superconductor, which in turn decreased a screening-current field (SCF) at the magnet center. We performed a finite element analysis with a simplified numerical model based on H formulation to verify whether magnetization-induced SCF is responsible for this 0.33% drop. Indeed, the model shows that the change of magnetization, i.e. screening-current reduction and current density redistribution, happens during temperature-cycle-induced Jc
(T) variation, and thus affects the center magnetic field. However, the Jc
(T) variation in the 2nd cycle had little effect on MgB2 magnetization and thus had negligible magnetic field change.
Visualization of non-linear convective Williamson liquid based on generalized heat-mass theories
Authors: Waqas M , Ahmad A , Asghar Z , Irfan M , Khan W A , Zubair M
Published: October 2020

This communication elaborates non-linear convection and heat sink/source effect in stretchable flow of Williamson fluid. Hydromagnetic laminar flow is examined. Heat-mass transport attributes are addressed via improved Fourier-Fick formulas. Conductivity and diffusivity of fluid depend on temperature and concentration. First-order chemical reaction aspect is also a part of current study. The concept of boundary-layer pioneered by Prandtl is utilized in order to simply the non-linear problems which are then reduced to the ordinary differential systems. Homotopy algorithm yields convergent outcomes of ordinary systems. A detailed analysis describing physical importance of pertinent variables is presented. Besides the obtained analytical outcomes are compared with the available numerical/exact outcomes and reasonable agreement is witnessed.
Coordination of Active and Reactive Power in Active Distribution Networks Based on Successive Linear Approximation
Authors: Wang Jinhui , Yuan Yue , Wu Han
Published: October 2020

Active distribution network (ADN) is an important part of the future power market, which undertakes the mission of accommodating high penetration distributed generation. However, traditional dispatch mode of the distribution system cannot accommodate high-penetrated renewable energy. In this paper, a novel optimal scheduling model is developed to optimize the accommodation of distributed renewable energy by coordinating active and reactive power. The proposed model takes capacitor bank (CB), energy storage systems (ESS) and static var generator (SVG) as management devices, optimize the day-ahead dispatchable resources of active distribution system in a centralized manner. Different from second-order cone programming method that cannot cooperate with the maximum DG penetration objective, we apply the successive linear approximation method to transform the original non-convex and nonlinear optimal dispatch model with AC balance equation into a mixed-integer linear programming (MILP) model, so that the model can be solved efficiently and accurately by commercial optimization software. A real distribution system in Nantong is employed to verify the proposed model.
SNIPER Based Multi-Target and Multi-Scale Aerial Image Processing Method
Authors: Li Yaocheng , Zhang Weidong , Cai Yingming , Li Zhe , Jiang Xiuchen
Published: October 2020

The maintenance of power transmission system appeals automatic inspection system to replace manual inspection. Inspection based on Unmanned Aerial Vehicle (UAV) generates a huge number of photos to be processed. These aerial photos have several challenging features: high density, small, scale variation. In order to ameliorate the performance on detection of important objects as insulators and pin bolts, an efficient multi-scale training algorithm called SNIPER is introduced. SNIPER enhanced Faster RCNN was trained on a powerline dataset for object detection. SNIPER provides a good average precision and average recall on large objects like insulators and medium objects with adequate annotated instances like pin bolts and dampers. However, SNIPER fails to locate missing pin or displaced pin, possibly due to their similarity to pin bolts. Future development of a SNIPER-based cascaded detection scheme could help detect defected small objects.
Test Study on Performance of Endothermic Highly Hydrophobic Anti-Icing Materials
Authors: Peng Yongjing , Fang Zhen , Hu Jianping , Wang Bowen , Xie Pengkang
Published: October 2020

In this paper, the solar spectrum selective endothermic coating with CoCuMnOx as the light absorbing pigment is prepared to absorb sunlight efficiently. After optimizing the thickness of the coating, the endothermic coating material with absorptivity of 0.928 and emissivity of 0.198 is obtained. The roughness value of the coating is 0.64 μm, which ensures that the coating has a higher sunlight absorption rate without the need for an antireflection layer. Icing flashover tests were carried out on insulators coated with endothermic highly hydrophobic anti-icing materials. The ice lightning voltage of ceramic insulators (3 pieces) was increased by 13.68%, and that of glass insulators (2 pieces) was increased by 22.96%. Compared with ceramic insulators, glass insulators coated with anti-icing materials have better protection effect.
Research on the Development Strategy of Platform-based Integrated Energy Service Providers in Power Internet of Things
Authors: Siwu Li , Bo Ruan , Yulin Yan , Zhu Chen , Fangmei Bie
Published: October 2020

The Power IoT (Power Internet of Things) has brought new commercial ecosystem for the whole energy industry, and that will greatly influence the IES (integrated energy services) market. With the continuous exploitation of IES market space, the commercial value of IES market is being re-evaluated by various market subjects. As a growing number of emerging market entities are trying to enter IES market, the development and maturity of IES market will be significantly promoted, and further competition of IES market will be intensified. This paper analyzes the commercial ecosystem of the Power IoT, based on its core technology architecture and industrial chain and the intrinsic association between Power IoT and IES. This paper also analyzes the pattern of the integrated energy service market, classifies the main body of the integrated energy service market, studies different types of IES market competition and the evolution path of market development, and puts forward the ecological development strategy for the core platform enterprises in IES market.
Simulation Research on Transient Junction Temperature Characteristics of High Power IGBT
Authors: Yong Tang , Bo Wang , Hong Chen Yong
Published: October 2020

Because the characteristics of semiconductor materials are greatly affected by temperature, the working characteristics of semiconductor electronic devices also change greatly with the change of temperature. High-power power electronic devices will bear larger conduction current and blocking voltage when working, and the temperature rise and fluctuation range will be more significant when working. Especially in the special working mode of short-time rest pulse, the junction temperature inside the chip will rise sharply and fluctuate greatly. The commonly used method of detecting the bottom plate shell temperature by thermocouple and then calculating the steady-state junction temperature can no longer meet the demand. According to this situation, this paper first analyzes the principle of junction temperature fluctuation of high-power power electronic devices, and then establishes the equivalent heat transfer model from the device bottom plate to the internal chip by using the multi-node heat transfer network method. Finally, the transient change and fluctuation process of the chip junction temperature during short-time intermittent pulse operation are obtained through simulation analysis, and the accuracy of the model is also verified.
Optimal Planning Method for Distributed Wind/Solar/Battery Intergraded Microgrid
Authors: Quan Zhu , Jian Wei , Liqun Ren , Yuxu Jin , Dan Zhou , Jiayao Qian , Tianyu Jiang
Published: October 2020

The high cost and randomness of intermittent renewable energy make the planning, integration and operation of power system more and more complicated. Therefore, determining the appropriate resource scale and related energy storage is the key to the efficient, economic and reliable operation of power system. In this study, two constraint based iterative search algorithms are proposed to optimize the scale of wind turbine (WT), solar photovoltaic (PV) and battery energy storage system (BESS) in microgrid grid connected configuration. The first algorithm is called resource size algorithm to determine the optimal size of resources; the second algorithm is called battery scale algorithm to determine the optimal capacity of BESS. These algorithms are mainly based on two key elements: maximum reliability and minimum cost. In this method, all possible solutions are searched in a given search space to avoid over and too small. At the same time, the forced outage rate of PV and the utilization rate of WT and Bess are considered to make it more practical. The simulation results show the effectiveness of the method.
Infrared Detection and Thermoelectric Coupling Simulation Analysis of 220 kV Insulator Abnormal Heating
Authors: Zhang Pipei , Wang Peng , Wang Jiangwei , Shi Wei , Li Jie
Published: October 2020

Heat and pollution flash caused by surface contamination are one of the common defects of insulators. If not discovered and eliminated in time, it will cause the deterioration of the insulator and seriously affect the service life of the insulator. If we can grasp the temperature distribution characteristics of the insulator in the state of contamination, the infrared temperature measurement can be used to quickly find and eliminate defects in a timely manner. This paper introduces a large area heating defect of porcelain post insulator and composite suspension insulator in 220kV equipment area, whose temperature distribution showed the rule of overheating at the high-voltage end and the temperature gradually decreasing toward the low-pressure end. Based on the field infrared temperature measurement and thermal image characteristics, it preliminarily analyzed that the heating was caused by insulator contamination and damp. Then, combined with pollution sampling, three-dimensional model establishment and thermoelectric coupling simulation calculation, the correctness of the above conclusions was verified, and preventive measures and suggestions were put forward.
FPGA-Based Real-Time Simulation for Multiple Energy Storage Systems
Authors: Tang Wenzuo , Li Zirun , Wang Yang , Zhang Chengke , Shao Li , Wang Keyou
Published: October 2020

Combining the renewable energy system, the Energy Storage (ES) station can maintain stable power transfer between renewable energy systems and power grid. This paper works on real-time simulation for multiple energy storage systems under different operating modes. Then taking a large number of ES converters and power grid into account, a modified electromagnetic transient program (EMTP) algorithm is proposed which is fit for the field-programmable gate array (FPGA)-based real-time simulation. By compressing the steps of the traditional EMTP algorithm, the simulation can be completed only by updating the history current source in each simulation cycle. In the meantime, the system is decoupled and multiple subsystems are simulated independently. Furthermore, to fully utilize the high parallelism of FPGA, we design and build a CPU-FPGA-based real-time simulation platform to implement the ES station. Using the simulation platform, we build a model of ES station and connect to the grid through an inverter. The whole system is tested in a single FPGA under different scenarios.
Configuration Optimization of Ultrasonic Descaling Device for Condenser Based on Solidworks-Fluent
Authors: Wang Min , Ge Xin , Wang Kedong
Published: October 2020

As a key component of the open circulation cooling system, the condenser of the power plant is very prone to fouling. After the condenser cooling pipe is scaled, the heat transfer resistance increases, which reduces the heat transfer coefficient and heat exchange efficiency of the heat exchange equipment, which is not conducive to improving the energy efficiency. Therefore, the research on condenser descaling technology has attracted widespread attention. Ultrasonic descaling is a new type of online descaling technology. Its application effect in descaling of condensers in power plants has been verified by actual engineering, but it lacks optimization of the arrangement and configuration of ultrasonic devices. In order to explore the influence of various ultrasonic parameters on the descaling effect, this paper builds a 3D geometric model of the condenser in Solidworks based on the relevant structural parameters of the N-20910 condenser, meshing the model reasonably and setting the boundary conditions. Then, in Fluent, the descaling effect is characterized by the pressure change curve of the specific position of the fluid in the condenser pipe. By setting three different ultrasonic inlet modes and different ultrasonic sound pressure functions, the effects of the quantity, power, frequency and distribution of ultrasonic descaler on the internal flow field and descaling effect of the condenser are compared and analyzed. The simulation results can provide effective help for the optimization and parameter setting of the ultrasonic descaling device of the power plant condenser.
Research on a Fundamental and Harmonic Detection Method Based on D-Q Rotating
Authors: Gong Jie , Xue Feng , Zhang Guangyi , Pan Wenhao , Wang Tingkang
Published: October 2020

The widespread use of power electronics in power systems has led to increasingly serious power quality problems in power systems. Active power filters play an important role in governing the harmonics of power systems. The fast and accurate detection of fundamental and harmonic currents in power systems is one of the key aspects of power filters to manage harmonics. In this paper, a new detection method for the fundamental or the nth harmonic component of the fundamental by presetting the frequency of the d-q conversion matrix is proposed. Analysis of simulation results shows that the detection method is not affected by the voltage distortion or asymmetry of the three-phase circuit, and that the results for fundamental and harmonic detection. The ability to accurately reflect changes in frequency and amplitude excursions.
A Study on the Extraction Method of Partial Discharge Features in Gas Insulated Switchgear Based on Ultra-High Frequency Signal Envelope
Authors: Chen Xiaoxin , Zhao Lin , Wang Shaoan , Sun Xiang , Qian Ping
Published: October 2020

Because the UHF detection method has the advantages of wide detection range and high sensitivity, it is of great significance for partial discharge detection and defect type identification in gas insulated electrical equipment. Therefore, this paper proposes a new type of partial discharge UHF signal pattern recognition algorithm, which can effectively identify the type of partial discharge defects. The low frequency signal modulated by high frequency signal is demodulated by Hilbert transform. This paper presents a method to extract the time domain characteristics of UHF signals emitted by gas insulated switchgears (GIS) partial discharge (PD). By using the Hilbert transform, the envelope of partial discharge signal can be obtained, and then the key points related to features in time domain can be obtained. The artificial insulation fault test platform is developed. Experimental data of three typical partial discharge signals are obtained, and the algorithm is analyzed and verified. The result shows that the method can recognize different types of PD well. So it is practical and effective.
Graphical Characteristics Analysis of PD Signals Phase Distributions of XLPE Cables
Authors: Lan Z J , Tian X Y , Wang Y P , Wu J L , Zhou Y W
Published: October 2020

Aiming at analysing the graphical characteristics of PD signals of XLPE cables, this introduced the methods of constructing four graphs of phase distribution: ϕ-Q-N distribution map, maximum discharge quantity phase distribution HQmax(ϕ), the mean of discharge quantit phase distribution HQmean(ϕ) and the discharge frequency phase distribution HN(ϕ). An experimental platform in laboratory was established to acquiring PD signals of four typical insulation defects of XLPE cables. The results show that different insulation defects leads to the PD signals which have distinct graphical characteristics. Corona discharge and surface discharge are asymmetrical in phase distribution while suspended electrode discharge and internal air gap discharge are symmetrical. The amplitudes of corona discharge are concentrated while the amplitudes of surface discharge vary greatly. The amplitudes of internal air gap discharge in two half-cycle are almost the same level while the amplitudes of suspended electrode discharge in positive half-cycle exceed that in negative half-cycle. According to these characteristics, it can be inferred which type of discharge the PD signals belongs to.
Analysis of the effectiveness of active paper use by adding garlic extract in inhibiting bacterial growth
Authors: Hidayat S H , Syarifuddin A , Dirpan A
Published: October 2020

Active paper is a component with antibacterial properties, often used as a microorganism resistance regulator, alongside ensure quality maintenance, and provide safety for packaged products. The purpose of this study, therefore, is to evaluate the effectiveness of active paper added with garlic extract in inhibiting bacterial growth. This involved the addition of 20% garlic extract, 30% tapioca starch (w / w), 100 mL of 1% acetic acid and chitosan powder into whatman paper pulp, followed by testing on Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa bacteria. The results showed a zone of bacterial inhibition with respective diameter of 3.68 mm, 3.98 mm and 1.98. However, active paper alone does not possess these inhibitory properties.
Chemical characteristic and sensory of tempeh sausage on different soybean varieties and cooking methods variation
Authors: Syamsuri Riswita , Dewayani Wanti , Septianti Erina , Maintang
Published: October 2020

Tempeh sausage is the one of variative and interesting processed provide added value and extend the shelf life of tempeh. The purpose of the research is to determine the quality of tempeh sausages, especially chemical and sensory content produced from various soybean varieties and variation of cooking methods. The research had a Complete Random Design of the factorial pattern with 3 repeats. The first factor is tempeh from various of soybean varieties (Import, Anjasmoro, Argomulyo, Burangrang, and Grobogan), the second factor is the cooking method (steamed, boiled and oven). The observation parameters include: moisture content, ash content, fat level, protein level, and sensory/organoleptic test. The result was showed that varieties of treatment and cooking methods gave a real interaction effect on ash content, fat content and protein of tempeh sausage. Tempeh sausage was produced from imported soybean, has the lowest water content for the oven cooking method and sausage tempeh of soybean Anjasmoro with steamed method has the lowest ash content. Tempeh sausage produced from soybean Argomulyo has the highest fat content for steamed cooking methods and the highest protein for the oven cooking method. Based on sensory analysis, it is known that having the highest level of preference is tempeh sausage from Grobogan and steamed treatment with a moisture content of 56.25%, ash content is 0.97%, fat 17.38%, and protein 12.91%.
The influence of effective length and reduction factor to buckling on jacket brace
Authors: Saleh A Abd. Rahman , Juswan  , Alie Muhammad Zubair Muis
Published: October 2020

The jacket is one of the fixed typical offshore structures consists of many braces located on not only deck legs but also the jacket its self. Those braces play an essential role in supporting the structure locally and globally from internal and external loads such as deck structure, current, and wave loads. The brace length has a significant influence on local buckling of the brace and will affect the global structure so that this influence should be checked. The objective of the present study is to analyze the influence of effective length and reduction factor to buckling of jacket brace, including the reduction factor according to API RP2A. The analysis is conducted using the analytical method, and the result is compared to the numerical method, including the behavior of jacket braces.
Sourcing new potential bacteriocin-producing bacteria from dangke, ethnic cheese of Enrekang, Indonesia
Authors: Djide N J N , Asri R M , Djide N
Published: October 2020

Bacteriocins are bioactive peptides produced by microorganisms. Sourcing of new bacteriocin-producing bacteria is essential as bacteriocin production depends on the microbial strain One of potential source for bacteriocin-producing microorganism is Dangke—a traditional cheese of Enrekang, South Sulawesi, Indonesia. Dangke contains compounds that can support the growth of lactic acid bacteria (LAB)—one of the well-known bacteriocin-producing bacteria. Specifically, this study focused on finding new strains of bacteriocin-producing LAB from dangke and screening its activity against pathogenic bacteria. LAB were isolated from cow and buffalo dangke using MRSA-CaCO3 1% media. The bacterial isolates obtained were identified based on 16S rRNA analysis. Fermentation was done in MRSB media in 37°C for 72 hours then concentrated with ammonium sulphate 80%, followed by dialysis. Crude bacteriocins were tested against Escherichia coli and Staphylococcus aureus. LAB strain B3B1 and S2A1 were successfully isolated from Dangke and were identified as Lactobacillus fermentum strain NBRC 15885 (identities 99%) and Weissella confusa strain JCM 1093 (identities 99%). Crude bacteriocin of L. fermentum strain NBRC 15885 was active against S. aureus with inhibition zone of 11.34 ± 2.97 cm. Based on the result, isolate B3B1 identified as Lactobacillus fermentum from buffalo dangke has potential in producing bacteriocin. Further studies of production, optimization, characterization and screening of other bioactivity of the bacteriocin are suggested
Planning ecotourism based on GIS in Gowa South Sulawesi
Authors: Mulyadi  , Nursyahputra M
Published: October 2020

The main objective of this study is to identify and prioritize the potential ecotourism sites using Geographic Information System (GIS) in Distric Gowa South of Sulawesi. This study identifies the following factors as indicators of suitability within land ecosystems: landscape/naturalness, wildlife, topography, accessibility and community characteristics. The evaluating process for ecotourism site conducted based on eight chosen criteria including land use/cover, reservation/protection, species diversity, elevation, slope, proximity to cultural sites, distance from roads and settlement size. Those factors were selected according to the professional expert’s opinions. GIS plays a crucial role in ecotourism planning. Aplication GIS –Base proposed was useful to identify ecotourism sites by linking the criteria deemed important with the actual resources of Gowa District.
Kajang customary law community bureaucratization? a transaction cost perspective
Authors: Anugrah D , Supratman  , Mas’ud E I
Published: October 2020

The research investigates bureaucratization indication of the institutional of the Kajang Customary Law Community. With the institutional economic framing and participatory action research method, we found the appearance of formal transaction fees that indicates bureaucratization of the institutional of the Kajang Customary Law Community. This condition is formed through the process of institutional assimilation.
The market campaign strategy of Greenpeace in decreasing rainforest deforestation in Indonesia: a case study of the usage of palm oil in Nestlé’s products
Authors: Syarifuddin E A , Cangara A R , Rahman I , Baharuddin A , Apriliani A
Published: October 2020

This research aims to portray the influence of Greenpeace’s movement in decreasing the rate of deforestation in Indonesia, using the study case of Greenpeace’s campaigns towards Nestlé. It focuses on a Greenpeace’s market campaign strategy towards Nestlé since March 2010 and on identifying its impacts. The type of research employed is descriptive analytic research, with data collecting techniques comprised of interviews and library researches. The result concludes that the Greenpeace’s market campaign strategy is identified as part of the New Social Movement. As an Environmental NGO, Greenpeace’s movement has a positive impact on the process of reducing deforestation in Indonesia. This can be seen on the transformation of Nestlé’s policy in protecting rainforests. Furthermore, Nestlé also stops buying palm oil products from any palm oil companies linked to deforestation. The impacts have been depicted by the declining number of deforestations in Indonesia within a few periods of time. This success has been also strengthened by the establishment of the Forest Moratorium, signed by President Susilo Bambang Yudhoyono and continued by President Joko Widodo, with the support and advocacy of Greenpeace.
Encouraging comparative advantages of export-oriented Indonesian agriculture products
Authors: Sulaiman Amran , Ali M. Saleh S. , Ahmad Ahfandi
Published: October 2020

Indonesia has the second-largest diversity of plants in the world after Brazil. This condition opens opportunities for Indonesia to produce a variety of crops, which cannot be planted or produced in other regions, such as in the subtropics or the four seasons in the northern or southern regions of the world. This study aims to analyze how to encourage the comparative advantage of export-oriented Indonesian agricultural products. To achieve this, it is necessary to strengthen the export policy of agricultural products; increasing productivity and production based on innovation and strengthening institutional exports of agricultural products. These efforts not only enhance the diversity of goods exported by Indonesia but also expand the markets of Indonesian products. Competition with countries that are in the top five exporters of world agricultural products, such as the United States and China, can be achieved by selling products that cannot be produced by other countries and increasing the competitiveness of products produced by Indonesia. Related to domestic regulations, the government needs to continue to build a business climate that facilitates and promotes export orientation, in addition to the various incentives provided.
Morphometric and meristic of an endemic fish Lagusia micracanthus bleeker 1860 from Ompo river, South Sulawesi
Authors: Nur M , Rahardjo M F , Simanjuntak C P H , Djumanto  , Krismono
Published: October 2020

Lagusia micracanthus is an endemic freshwater fish species of South Sulawesi, Indonesia. The present study performs morphometric characteristics and meristic counts to L. micracanthus inhabiting Ompo River, South Sulawesi. Fishes were collected from the Ompo River in April 2018. Morphometric and meristic measurements were performed by following methods of Vari (1978), Vari & Hutchins (1978) and Shelley et al. (2017). Other additional measurements were based on Hubbs & Lagler (1974). Statistical analysis such as regression equation and correlation coefficient was following method of Brraich and Akhter (2015). An amount of 31 morphometric characters and 9 meristic counts were recorded from 30 fishes. Analysis of correlation on morphometric characters demonstrates six characters with high correlation coefficient, eighteen characters with moderate coefficient, and six characters with low coefficient.