bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of 3D printed buckyball-shaped cathodes of titanium and stainless-steel for IEC fusion system
Authors: Bakr Mahmoud , Wulfkühler Jan-Philipp , Mukai Keisuke , Masuda Kai , Tajmar Martin , Konishi Satoshi
Published: January 2021

An inertial electrostatic confinement (IEC) fusion device accelerates ions, such as deuterium (D) or tritium (T), to produce nuclear fusion and generate neutrons. The IEC's straightforward configuration consists of a concentric spherical transparent cathode at a negative bias surrounded by a grounded spherical anode. The effects of cathode properties on the neutron production rate (NPR) remain, to date, inadequately studied. This study aims to determine the impact of the cathode material on the NPR by investigating fusion reactions on the cathode surface. Two buckyball-shaped cathodes made of stainless steel (SS) and titanium (Ti), both of 5 cm diameter, fabricated by selective laser melting and 3D printing, are used for this investigation. A SS spherical chamber of 25 cm inner diameter is used as an anode in this experiment. A performance evaluation of surface fusion reaction in the IEC using SS and Ti grids is conducted by examining the NPR as a function of the applied voltage and grid currents at different gas pressures. So far, IEC with Ti and SS cathodes achieves NPRs of 2.32 and 1.41 × 107 n/s, respectively, at 5.6 kW (70 kV, 80 mA). The normalized NPRs (NPR/I-cathode) from IEC using SS and Ti cathodes are compared. The results demonstrate that fusion reaction occurs on the cathode surface, and fusion increases with the applied voltage. The measured NPR/I-cathode using the Ti cathode is higher than that of the SS cathode by factors of 1.36–1.64 across the 20–70 kV range. Moreover, fusion on the Ti cathode surface enhances the total NPR significantly compared to the SS cathode under the same conditions. The Ti's considerable ability to accumulate D ions and molecules compared with that of SS explains the difference of measured NPR results.
Ferroelectricity of as-deposited HZO fabricated by plasma-enhanced atomic layer deposition at 300 °C by inserting TiO2 interlayers
Authors: Qi Yuanshen , Xu Xianbin , Krylov Igor , Eizenberg Moshe
Published: January 2021

We report the observation of ferroelectricity in hafnium-zirconium-oxide thin films in the as-deposited state, namely, after deposition at a low temperature of 300 °C without post-metallization annealing. The Hf0.5Zr0.5O2 (HZO) thin film was interposed between two TiO2 interlayers, and all films were produced by plasma enhanced atomic layer deposition and integrated into a TiN-based metal-insulator-metal capacitor. The ferroelectric nature of the as-deposited HZO film was evaluated by a polarization-voltage hysteresis loop, and a 2Pr value of ∼7.4 μC/cm2 was achieved. Grazing incidence x-ray diffraction measurements and atomic-resolution scanning transmission electron microscopy characterization revealed the co-existence of fully crystallized polar orthorhombic and monoclinic phases of the dielectric in the as-deposited sample. We concluded that the nucleation and growth of the crystalline polar non-centrosymmetric orthorhombic phases in the 10 nm HZO thin film were prompted by the available energy from the plasma and the tensile lattice mismatch strain provided by the TiO2 interlayer.
Time compression of frequency-modulated pulses in fibres with in-fibre refractive index gratings
Authors: Abramov A.S. , Zolotovskii I.O. , Kamynin V.A. , Lapin V.A.
Published: January 2021

The dynamics of frequency-modulated pulses in fibres with sequentially inscribed refractive-index gratings having a different period is considered. It is shown that the proposed structure of the fibre can be used to generate picosecond and subpicosecond pulses with peak powers on the order of 1 MW.
Experimental technique for studying optical absorption in waveguide layers of semiconductor laser heterostructures
Authors: Bobretsova Yu.K. , Veselov D.A. , Podoskin A.A. , Voronkova N.V. , Slipchenko S.O. , Ladugin M.A. , Bagaev T.A. , Marmalyuk A.A. , Pikhtin N.A.
Published: January 2021

We report a technique for studying the absorption of optical radiation in layers of a semiconductor heterostructure by the method of probe radiation coupling. The studies are carried out using specially made isotype samples based on AlGaAs/GaAs, simulating an n-type doped laser waveguide with a concentration of 1017 – 1018cm−3. The main features of the experimental setup and calculation methods are described. A high (up to 95%) efficiency of light coupling into the waveguide and an error in measuring the absorption coefficient at a level of 0.1 cm−1 are achieved. The possibilities of studying the polarisation and temperature dependences of radiation absorption by free carriers are experimentally demonstrated. It is shown that with an increase in temperature in the range 25 – 85°C, the absorption in the samples increases by 15%.
Simulation on the nonuniform electrical pumping efficiency of THz quantum-cascade lasers
Authors: Dolgov A.K. , Ushakov D.V. , Afonenko A.A. , Dyuzhikov I.N. , Glinskiy I.A. , Ponomarev D.S. , Khabibullin R.A.
Published: January 2021

The efficiency of electric pumping of THz quantum-cascade lasers (QCLs) with strip geometry is studied depending on the number and position of contact pads. The numerical simulation of the electric potential distribution in the THz QCL active region is used to determine the required thicknesses of the upper metallisation layers of the THz QCLs to minimize the voltage drop along the laser structure in the case of nonuniform current supply. It is found that the efficiency of electric pumping in the case of a centrally located contact is significantly higher than when the contact pads are located near the laser structure edges. From the calculated dependence of the THz QCL integral power on the thickness of the upper metal layer, it is shown that for effective current injection, the contact pads must be located at a distance of less than 0.5 mm from each other.
Limiting spectral and angular characteristics of sawtooth dual-relief two-layer diffraction microstructures
Authors: Greisukh G.I. , Ezhov E.G. , Zakharov O.A. , Danilov V.A. , Usievich B.A.
Published: January 2021

Sawtooth two-layer microstructures with internal and external, as well as with two internal reliefs, composed of technological and commercially available optical plastics or an optical plastic and nanocomposite material are investigated. By using the corresponding model microstructures in the frameworks of the rigorous diffraction theory, the limiting spectral and angular characteristics are estimated for sawtooth two-layer dual-relief diffraction microstructures of both types.
The neuropeptide allatostatin C from clock-associated DN1p neurons generates the circadian rhythm for oogenesis
Authors: Zhang Chen , Daubnerova Ivana , Jang Yong-Hoon , Kondo Shu , Žitňan Dušan , Kim Young-Joon
Published: January 2021

Significance

Metazoan species optimize the timing of reproduction to maximize fitness. To understand how biological clocks direct reproduction, we investigated the neural substrates that produce oogenesis rhythms in the genetically amenable model organism
Drosophila melanogaster
. The neuropeptide allatostatin C (AstC) is an insect counterpart of the vertebrate neuropeptide somatostatin, which suppresses gonadotropin production. A subset of the brain circadian pacemaker neurons produces AstC. We have uncovered that these clock-associated AstC neurons generate the circadian oogenesis rhythm via brain insulin-producing cells and the insect gonadotropin juvenile hormone. Identification of a conserved neuropeptide pathway that links female reproduction and the biological clock offers insight into the molecular mechanisms that direct reproductive timing.
Ecological adaptation in European eels is based on phenotypic plasticity
Authors: Enbody Erik D. , Pettersson Mats E. , Sprehn C. Grace , Palm Stefan , Wickström Håkan , Andersson Leif
Published: January 2021

Significance

Populations within a species may experience genetic adaptation to local environmental conditions while individuals may tolerate variation in environmental conditions due to phenotypic plasticity. European eels reproduce in the Sargasso Sea but spend most of their adult life in highly diverse environmental conditions from northern Europe to North Africa. An unresolved question is whether this species constitutes a single panmictic population or if locally adapted subpopulations occur. Here we conclude, based on whole-genome sequencing, that there is a complete absence of genetic differentiation among eels from different parts of Europe and North Africa. Thus, we postulate that European eels must respond to the extremely diverse ecological conditions they inhabit during the postlarval stages by phenotypic plasticity.
Latent extinction risk of soil fauna in Beijing: a 4-year study from 2013 to 2016
Authors: Wang Wei , Ren Qilin , Zhang Runzhi , Wu Pengxiang
Published: January 2021

Soil ecosystems are far more functionally valuable than previously thought, but soil animals are less visible and often overlooked. Here, we surveyed population sizes of different animal orders in both urban and rural Beijing from 2013 to 2016, to study the impact of increasing urbanization on the ecology of soil fauna. We found 10 orders had less than 1% of soil-animal population in both urban and rural areas. Populations of 6 orders in urban areas were far smaller than those in rural areas. Between 2013 and 2016, both urban and rural areas had experienced a substantial long-term population decrease, and soil animals in Beijing suffered a 52.8% loss of population. Our study indicates 45.5% of orders may be in danger of local extinction, and 27.3% of orders seem highly susceptible to urbanization. Over just four years the soil-animal population in Beijing is shrinking fast thanks largely to increasing urbanization. This raises the worrying prospect of a future soil fauna that may be at risk of local extinction in cities. It is therefore necessary to provide a pragmatic approach to soil-animal diversity conservation. Moreover, the deeper understanding of soil extinction ecology opens up an exciting frontier of opportunities for future research.
CEP55 promotes cilia disassembly through stabilizing Aurora A kinase
Authors: Zhang Yu-Cheng , Bai Yun-Feng , Yuan Jin-Feng , Shen Xiao-Lin , Xu Yu-Ling , Jian Xiao-Xiao , Li Sen , Song Zeng-Qing , Hu Huai-Bin , Li Pei-Yao , Tu Hai-Qing , Han Qiu-Ying , Wang Na , Li Ai-Ling , Zhang Xue-Min , Wu Min , Zhou Tao , Li Hui-Yan
Published: January 2021

Primary cilia protrude from the cell surface and have diverse roles during development and disease, which depends on the precise timing and control of cilia assembly and disassembly. Inactivation of assembly often causes cilia defects and underlies ciliopathy, while diseases caused by dysfunction in disassembly remain largely unknown. Here, we demonstrate that CEP55 functions as a cilia disassembly regulator to participate in ciliopathy. Cep55−/− mice display clinical manifestations of Meckel–Gruber syndrome, including perinatal death, polycystic kidneys, and abnormalities in the CNS. Interestingly, Cep55−/− mice exhibit an abnormal elongation of cilia on these tissues. Mechanistically, CEP55 promotes cilia disassembly by interacting with and stabilizing Aurora A kinase, which is achieved through facilitating the chaperonin CCT complex to Aurora A. In addition, CEP55 mutation in Meckel–Gruber syndrome causes the failure of cilia disassembly. Thus, our study establishes a cilia disassembly role for CEP55 in vivo, coupling defects in cilia disassembly to ciliopathy and further suggesting that proper cilia dynamics are critical for mammalian development.
New investigators in the time of the COVID-19 pandemic
Authors: Casadio Melina , Simon Dan
Published: January 2021

JCB checks in with newly independent cell biologists and learns about their experience running a lab during the COVID-19 pandemic.
Control of double Fano resonances to double optomechanically induced transparencies in a four-mirror cavity set
Authors: uddin Zia , Awais Muhammad , Hussain Ibrar , Ahmad Saeed , Abbas Muqaddar
Published: January 2021

We theoretically demonstrate the characteristics of an output probe field by considering a set of four mirrors that form a cavity system. In a set of four mirrors, two are fixed while two are moveable and each is driven by an external pump field. Each oscillatory mirror has an external plate (mirror) which can generate a Casimir force (CF). The two CFs affect the radiation pressure inside the cavity, influencing the output probe field profile. The double Fano profile is obtained in the presence of CF for different mechanical frequencies as well as for the same mechanical frequencies. Interestingly, we predicted that double Fano resonances occur in the presence of CF, while double optomechanically induced transparency (OMIT) occurs in the absence of CF. The switching between double Fano resonances and double OMIT is also investigated via CF.
Supporting capacity of a ferrofluid ring bearing
Authors: Xie Xingfei , Dai Qingwen , Huang Wei , Wang Xiaolei
Published: January 2021

In this paper, the supporting capacity of a ferrofluids (FFs) ring bearing is investigated experimentally and numerically. The bearing consists of a floating plate, a substrate, and a FFs ring sandwiched between them. The FFs ring is formed and restrained by applying a ring magnet below the substrate. For a FFs ring with a thickness of 0.25 mm, the maximum supporting force is about 1.78 N. Numerical analysis reveals that, compared with the Laplace force, the magnetic force plays a dominating role in the total supporting force. Such a liquid ring support may give underlying applications for frictionless bearings or precision positioning systems.
Compositionally graded III-nitride alloys: building blocks for efficient ultraviolet optoelectronics and power electronics
Authors: Zhang Haochen , Huang Chen , Song Kang , Yu Huabin , Xing Chong , Wang Danhao , Liu Zhongling , Sun Haiding
Published: January 2021

Wide bandgap aluminum gallium nitride (AlGaN) semiconductor alloys have established themselves as the key materials for building ultraviolet (UV) optoelectronic and power electronic devices. However, further improvements to device performance are lagging, largely due to the difficulties in precisely controlling carrier behavior, both carrier generation and carrier transport, within AlGaN-based devices. Fortunately, it has been discovered that instead of using AlGaN layers with fixed Al compositions, by grading the Al composition along the growth direction, it is possible to (1) generate high-density electrons and holes via polarization-induced doping; (2) manipulate carrier transport behavior via energy band modulation, also known as ‘band engineering’. Consequently, such compositionally graded AlGaN alloys have attracted extensive interest as promising building blocks for efficient AlGaN-based UV light emitters and power electronic devices. In this review, we focus on the unique physical properties of graded AlGaN alloys and highlight the key roles that such graded structures play in device exploration. Firstly, we elaborate on the underlying mechanisms of efficient carrier generation and transport manipulation enabled by graded AlGaN alloys. Thereafter, we comprehensively summarize and discuss the recent progress in UV light emitters and power electronic devices incorporating graded AlGaN structures. Finally, we outline the prospects associated with the implementation of graded AlGaN alloys in the pursuit of high-performance optoelectronic and power electronic devices.
Rotating squares auxetic metamaterials with improved strain tolerance
Authors: Sorrentino A , Castagnetti D , Mizzi L , Spaggiari A
Published: January 2021

Rotating squares auxetic metamaterials have the peculiar feature of a negative Poisson’s ratio. This work proposes and examines how an innovative variable arcs fillet solution, at the interconnection regions between the rotating units, improves the structural response of a titanium alloy-based rotating squares metamaterial. Through a 2D finite element (FE) model of the auxetic structure, we investigated and optimized two fillet configurations: first, a double circular arcs profile; second, a combined elliptical and circular arc fillet. According to the FE results, the optimal configuration of the combined elliptical and circular arc fillet allows an overall 3% elastic strain of the metamaterial, with a Poisson’s ratio (PR) equal to ca. −1. In order to assess the deformation behavior of the proposed metamaterial, we performed a tensile test on a prototype of the optimal solution, 3D printed in Onyx material. The experimental displacement field of the specimen, measured through digital image correlation, exhibited excellent agreement with the FE predictions, with a PR equal to ca. −1 up to a 3% overall strain.
A new hyperchaotic complex system and its synchronization realization
Authors: Li Zhengfeng , Zhang Fangfang , Zhang Xue , Zhao Yang
Published: January 2021

In this paper, we propose a new hyperchaotic complex system and systematically study its basic dynamic characteristics such as dissipation, Lyapunov exponent, attractor, parameter changes, and

Poincar

e

́

cross-section. The system is based on the complex Lorenz chaotic system, and the chaotic system has higher dimensionality and more parameters than complex Lorenz system. We provide a general method for constructing complex chaotic systems. We use the state linear feedback method to realize the synchronization control of the chaotic system as the driving system and the response system and simulate all of the systems by Simulink. The chaotic system and its synchronization simulation are simulated by Simulink to verify their hardware feasibility.
Tunable unidirectional reflectionless propagation in non-Hermitian graphene plasmonic waveguide system
Authors: Ding Jian , Wang Yueke
Published: January 2021

In this paper, a non-Hermitian graphene plasmonic waveguide system is proposed in the mid-infrared region. The proposed structure consists of two resonators and a graphene waveguide, which are attached to the SiO2 substrate. Based on the far-field coupling between the two stub plasmonic resonators, the single-band unidirectional reflectionless phenomenon of fundamental edge plasmonic mode in the non-Hermitian waveguide system has been theoretically studied. It can be found that when plasmonic mode is incident from one side, the reflection is 0, but from the other side, the reflection is 26.212%, so an exceptional point (EP) appears. Furthermore, the EP blueshifts with increasing Fermi level, and is unchanged under different relaxation times. All the simulation results are conducted by finite element method. Therefore, our findings pave a new way for the development of terahertz sensors, diodes, and so on.
Asymmetric defects in one-dimensional photonic lattices
Authors: Jovanović Slavica , Krasić Marija Stojanović
Published: January 2021

The influence of linear and nonlinear asymmetric defects on light beam propagation in a one-dimensional photonic lattice has been numerically analysed. Defects are located in a uniform or composite lattice and can be linear or nonlinear in both cases. The results obtained for the uniform lattice were compared with those obtained for the composite lattice. The asymmetric defect width was varied. It was found that the width of asymmetric defects plays a significant role in light beam propagation. A comparison with the corresponding symmetric defects was also performed. Various types of strongly localized defect modes were found at the defect position as well as in the cavities between the asymmetric defects or an asymmetric defect and the interface. In addition to localized modes, we found reflection and transmission of light.
On the new exact traveling wave solutions of the time-space fractional strain wave equation in microstructured solids via the variational method
Authors: Wang Kang-Jia
Published: January 2021

In this paper, we mainly study the time-space fractional strain wave equation in microstructured solids. He’s variational method, combined with the two-scale transform are implemented to seek the solitary and periodic wave solutions of the time-space strain wave equation. The main advantage of the variational method is that it can reduce the order of the differential equation, thus simplifying the equation, making the solving process more intuitive and avoiding the tedious solving process. Finally, the numerical results are shown in the form of 3D and 2D graphs to prove the applicability and effectiveness of the method. The obtained results in this work are expected to shed a bright light on the study of fractional nonlinear partial differential equations in physics.
Vector NLS solitons interacting with a boundary*
Authors: Zhang Cheng , Zhang Da-jun
Published: January 2021

We construct multi-soliton solutions of the n-component vector nonlinear Schrödinger equation on the half-line subject to two classes of integrable boundary conditions (BCs): the homogeneous Robin BCs and the mixed Neumann/Dirichlet BCs. The construction is based on the so-called dressing the boundary, which generates soliton solutions by preserving the integrable BCs at each step of the Darboux-dressing process. Under the Robin BCs, examples, including boundary-bound solitons, are explicitly derived; under the mixed Neumann/Dirichlet BCs, the boundary can act as a polarizer that tunes different components of the vector solitons. Connection of our construction to the inverse scattering transform is also provided.
Non-line-of-sight transparent object detection and reconstruction based on passive single-pixel imaging
Authors: Li Mengdi , Mathai Anumol , Xu Xiping , Wang Xin , Pan Yue , Gao Xuefeng
Published: January 2021

Single-pixel imaging (SPI) uses point detectors instead of expensive array sensors to capture images under low light conditions. It therefore provides a solution in detecting objects with weak signals. In this research, we propose a non-line-of-sight (NLOS) 2D transparent object inspection system based on SPI technique. The 2D shape of the transparent object is reconstructed using Total Variation Augmented Lagrangian and Alternating Direction Algorithm (TVAL3) approach by collecting indirect light reflected from the object surface. Theoretical analysis shows that 300 illumination patterns are required to reconstruct a

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pixel image, and those patterns are streamed to the digital micromirror device at high speed. Compared to TVAL3 with other methods, better image quality can be obtained with only one-third of illumination patterns. Also, experimental results confirm that this system can obtain transparent object information from reflected light even at a sampling rate of 24%. Furthermore, adjusting the laser wavelength and laser power can improve image quality. The proposed SPI detection system for NLOS transparent objects is an effective method that requires fewer illumination patterns and provides new insights for the detection and reconstruction of NLOS transparent object.
Accurate ground-to-ground laser time transfer by diffuse reflections from tumbling space debris objects
Authors: Liu T , Eckl J J , Steindorfer M , Wang P , Schreiber K U
Published: January 2021

The optical two-way time transfer between two widely separated laser ranging ground stations in common view of a space debris target can be achieved from diffuse laser pulse reflections. The round-trip time-of-flight measurements augmented by the detection and epoch timing of diffusely scattered laser light from the second ground station allows accurate clock comparisons, provided that the mean location of the point of reflection on the target structure can be recovered with sufficient fidelity. We have set up a target delay model that derives the tumbling motion of rocket bodies from a combination of laser ranging and photometric measurements. Combined with the simultaneously measured short arc orbit, we obtain the applicable in situ propagation delay for the time transfer signal between the two ground stations in order to establish the clock offset between them. We show an example where the uncertainty of this clock synchronization for a time-of-flight comparison already reaches 3 ns. We point out that there is still significant room for improvement.
Growth signals determine the topology of evolving networks
Authors: Vranić Ana , Dankulov Marija Mitrović
Published: January 2021

Network science provides an indispensable theoretical framework for studying the structure and function of real complex systems. Different network models are often used for finding the rules that govern their evolution, whereby the correct choice of model details is crucial for obtaining relevant insights. Here, we study how the structure of networks generated with the aging nodes model depends on the properties of the growth signal. We use different fluctuating signals and compare structural dissimilarities of the networks with those obtained with a constant growth signal. We show that networks with power-law degree distributions, which are obtained with time-varying growth signals, are correlated and clustered, while networks obtained with a constant growth signal are not. Indeed, the properties of the growth signal significantly determine the topology of the obtained networks and thus ought to be considered prominently in models of complex systems.
An Ergonomics Approach of The Prayer Mat Size
Authors: Karim Abdul Alimul , Suprapto Sena Sukmananda , Gufron Muhammad
Published: January 2021

Currently, Indonesia does not have a standard size for prayer mats. For this reason, the size of the prayer mat should be designed according to Islamic requirements and laws. This can be done by measuring the human body which is directly related to determining the dimensions of the prayer mat. The length and width of the prayer mat can be determined by knowing the length of the prostration and the width of the shoulders. This research was conducted using an ergonomic approach with anthropometric methods and the cosine formula. This study focuses on male and female adult prayer mats. This research resulted in the length of the prayer mats 1277.12 mm and 1229.1 mm, while the widths of the prayer mats were 805 mm and 744 mm.
Firefly Algorithm for Multi-type Vehicle Routing Problem
Authors: Jamil Ahmad , Abdallah Bayu Nur , Leksono Vridayani Anggi
Published: January 2021

The problem of distribution is a problem that cannot be separated from the industrial world. These problems are because these problems have a considerable influence on the cost and level of service to consumers. Therefore we need a way so that the distribution process can run smoothly and on time. One way that can be done in the distribution process is to optimize vehicle routes so that the time spent serving two consumers is more efficient and the goods can get to consumers on time. The problem of optimizing vehicle routes is known as vehicle routing problem (VRP). VRP which aims to form an optimal route to serve consumers with capacity constraints and Type of Vehicle is called Multi-type vehicle routing problem (MTVRP). In solving the MTVRP problem, two methods will be combined namely the exact method and the heuristic method. The firefly algorithm has been widely used in solving VRP problems. The results are obtained total distance of 2488 km.
Analysis of Using Regularization Technique in The Convolutional Neural Network Architecture to Detect Paddy Disease for Small Dataset
Authors: Mujahidin S , Azhar N F , Prihasto B
Published: January 2021

In some instances, convolutional neural network (CNN) methods such as large numbers of datasets can show very high accuracy. However, in cases such as the small number of datasets, the accuracy performance of CNN often decreases. This also intersects with the constraints of applying CNN to recognize types of diseases in rice with a small number of datasets. This research applied the combination of regularization techniques and CNN methods to recognize rice disease types with a total dataset reaching 120 leaf images. It is found that using CNN-regularization techniques shows better performance than standard CNN architecture. With an accuracy value reaching an average of 85, 878%, it is expected to open further research opportunities.
Evaluation of The Application of Hospital Management Information System (SIMRS) in RSUD Dr. Kanujoso Djatiwibowo Using The HOT-Fit Method
Authors: Setiorini Adani , Natasia Sri R , Wiranti Yuyun Tri , Ramadhan Dean A
Published: January 2021

Hospital Management Information System (SIMRS) is a system that can process and integrate the entire hospital service process flow in the form of a network of coordination, reporting and administrative procedures to obtain accurate data and information. At the RSUD Dr. Kanujoso Djatiwibowo (RSKD) of Balikpapan City, the application of SIMRS experienced problems such as the high number of troubleshooting cases and the redundancy of patient medical record numbers. This case is considered to inhibit the performance of hospital services related to efficiency. Based on this problem, the evaluation of SIMRS in the RSKD was carried out by using the constructed Human, Organization, Technology-Fit (HOT-Fit) model. This model involves eight variables which consists of System Quality, Information Quality, and Service Quality, System Use, User Satisfaction, Structure, and Environment, and Net Benefits. The results indicate that the proposed model either directly or indirectly affects the benefits obtained from implementing the SIMRS. Further implications of the results toward improvement of the system are provided.
Numerical Study of Secondary Flow Characteristics on the Use of the Winglets
Authors: Setyo Hariyadi S P , Sutardi  , Widodo Wawan Aries , Sonhaji Imam
Published: January 2021

The upper surface of the wing is constantly observed by experts on the wing. In this area, a variety of phenomena cause how much aerodynamic performance is demonstrated. Changing or adding geometry to the wing changes the flow characteristics of the upper surface. The use of winglets will certainly change the flow characteristics around the wingtip which will have a large effect on the area behind and next to the winglet itself. This research was carried out using Ansys 19.1 and the turbulent k-ω SST model. The airfoil used is Eppler 562 which is commonly used in unmanned aerial vehicles. Freestream flow velocity that will be used is 10 m/s (Re = 2.34 x 104) with an angle of attack (α) = 12° and 15°. From this study, it was found that the pressure contour in the y-z plane showed a reduction in area and intensity through the use of winglets. Secondary flow formed by using the forward wingtip fence results in a smaller area around the wingtip area than other configurations. Besides, the value of pressure on the upper surface which is equipped with a forward wingtip fence shows that pressure is still quite high when compared to the others.
Simulation of Illipe Butter Purification Originated from West Kalimantan by SuperPro Designer
Authors: Ramadhani Nurul Hikmah , Darmawan Muhammad Arif , Perdana Harahap Andre Fahriz , Arya Ramadhan Muhammad Yusuf , Silalahi Ursula Chriseva , Gozan Misri
Published: January 2021

Tengkawang is one of the commodities of non-timber forest products which has been a life of support for people around the forest. Seeds produced by Tengkawang trees are one of the export commodities. However, unfortunately, the process of exporting Tengkawang seeds abroad often requires a long time to reduce the quality of the Tengkawang seeds. Processing of Tengkawang seeds into oil is a solution to the decline in quality of Tengkawang seeds. Like standard crude vegetable oil, Tengkawang oil also contains impurities. Therefore, a purification process to remove these impurities is needed. This research was conducted to produce purified Tengkawang fat optimally. Purification stages include degumming, neutralization and bleaching. This research will focus on the simulation of purified Tengkawang fat production. In this case, the simulation is carried out as an estimator of the feasibility value roughly whether a fat purification plant can be realized or not.
Kinetic Studies of Methylene Blue Degradation using CaTiO3Photocatalyst from Chicken Eggshells
Authors: Ernawati Lusi , Yusariarta Ade Wahyu , Laksono Andromeda Dwi , Wahyuono Ruri Agung , Widiyandari Hendri , Rebeka Rebeka , Sitompul Virginia
Published: January 2021

This study details the kinetic of photodegradation of methylene blue in aqueous medium using CaTiO3photocatalyst. The CaTiO3catalyst was prepared by sol-gel reaction using CaCO3derived from chicken eggshell and anatase TiO2powder. The CaTiO3particles were prepared using a mixture of starting materials in of (1:1); (1:3); (2:5) and (2:7) CaCO3/TiO2molar ratio at T = 900°C. The physical and microstructural properties of CaTiO3microstructural were characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), Fourier Transform Infrared (FTIR) and UV/vis spectrometer. As prepared CaTiO3particles with various composition of CaCO3/TiO2were then applied for removal of dye molecules under simulated UV irradiation. The effect of initial dye concentration, catalyst composition, and degradation time on the adsorption property of CaTiO3was systematically investigated. The results reveal that methylene blue (MB) molecules are efficiently adsorbed and degraded within 120 min using CaTiO3catalysts. Considering the low-cost preparation process and considerably high photocatalytic performance obtained in this work, CaTiO3can further be used as an efficient photocatalyst for organic pollutant removal from industrial wastewater.
Synthesis of Chitosan/Hydroxyapatite Nanofibers as A Wound Dressing via Electrospinning Method
Authors: Fauziyah M , Salsabila T , Setyawan H , Widiyastuti W
Published: January 2021

Nanotechnology had been widely developed for medical application in various forms, either nanoparticles or nanofibers. One of the most attractive use is nanofibers as a wound dressing. An ideal wound dressing should have characteristics of easily sterilized, non-toxic, biodegradable, good oxygen circulation, and anti-microbial performance. Those characteristics could be obtained by using a biomaterial composite which had a good biocompatibility on human body tissues, such as chitosan and hydroxyapatite (HA). Chitosan had an anti-microbial property, while HA could increase the cell generation rate. Therefore, this work would synthesize a chitosan/HA nanofiber as a potential wound dressing via electrospinning method. HA was firstly prepared by electrolysis using alternating electrode configuration. The dope solution of chitosan/HA for electrospinning was prepared by adding polyvinyl alcohol (PVA) as a coadjutant polymer. The morphology of the obtained nanofibers was investigated by SEM. It was revealed that the nanofibers had an average diameter of 261.87 nm which was spun each other forming many pores which was good for oxygen circulation. Therefore, chitosan/HA nanofibers could be a promising material for wound dressing application.
Design of impeller blades in the intermediate stage of centrifugal pump to a preset shape of meridional flow pattern
Authors: Kostornoi A S , Tkach P Yu , Bondariev O O , Podopryhora N N
Published: January 2021

While designing the stages of a centrifugal pump, there is an important and difficult task of impeller blade design. This article deals with an approach to impeller blade design that is based on analytical choice of dependency of flow change along the streamline. The given approach is implemented at JSC “VNIIAEN” in form of custom software which lets the user build a line drawing based on given parameters in normal duty of intermediate stage by designing the blade and calculating the geometrical dimensions of the impeller. The given method has been tested and proven with a physics experiment.
Numerical simulation and experimental investigation of submersible sewage mixer performance
Authors: Błoński D , Szulc P , Machalski A , Rogula J
Published: January 2021

This work focuses on methods of submersible sewage mixer performance evaluation comparison. In the paper an experiment with a submersible mixer with a published and known geometry has been presented. The authors measured thrust, torque rotation speed and electric power. Experiment was compared with results obtained with a steady state numerical simulation. Next CFD results were checked with a theoretical approach for the mixing range. Both theoretical and numerical methods showed good applicability for the industry.
Influence of construction and operating pump parameters on pressure pulsations amplitude
Authors: Sotnyk M I , Moskalenko V V , Strokin O O , Antonenko S S , Sapozhnikov S V
Published: January 2021

The research results that presented in the article are focused on decreasing the intensity of pressure pulsations in the flowing part of centrifugal pumps. The aim of the work is researching influence of changes in construction and/or operating pump parameters on pressure pulsations amplitude. Basing on the research results, were determined the main sources of pressure pulsations in the flowing part of the spiral centrifugal pumps and the reasons of increasing their amplitude during pump operation mode at supply 0.3Qopt…0.7Qopt. The article presents information about dependencies of pump head and pressure pulsations amplitude on construction and operating pump parameters, such as: number of blades (z), blade width at the impeller outlet (b2), ratio of volute initial diameter to impeller outer diameter (D3/D2), angle of output edge inclination (φ), rotor rotation frequency (n) and blades position of impeller halves in relative to each other (shift step - ψ).
Investigation of the operating process of a high-pressure centrifugal pump with taking into account of improvement the process of fluid flowing in its flowing part
Authors: Kondus V Y , Gusak O G , Yevtushenko J V
Published: January 2021

Centrifugal pumps are used in most industries. In particular, they are effectively used in the technological processes of oil production to create reservoir pressure at oil fields. Due to increasing demand for petroleum products, there is a need to improve such pumps to increase reservoir pressure by increasing their pressure. The research considered the possibility of improving the centrifugal pump impeller design by changing its blade system. It is theoretically possible to increase the pump head by changing the blade outlet angle at the impeller outlet β2 to 75°. The design of additional wedge-shaped blades of the second tier of the impeller was developed to reduce some additional hydraulic losses zones. They made it possible to stabilize the fluid flow in the impeller intervane channels, to reduce additional hydraulic losses. In the research, the impeller head was increased up to 26.7% for the proposed design impeller compared to the standard one. The research was performed with a comprehensive analysis of the pump installation life cycle cost. Thus, the development of new ones and the upgrading of pumping installations rooted in the industry with the aim of increasing the head is possible while achieving the minimum pump installation life cycle cost.
The influence of the impeller construction on the performance of one channel pump
Authors: Szulc P , Moliński G , Moloshnyi O
Published: January 2021

The paper presents the comparison of the impeller’s construction on the operating parameters of the sewage pump. Three types of impellers were taken into consideration. The main geometrical parameters were identical, the differences were applied in the meridional cross–section and in the shape of the passages. These three objects of research represent three approaches of the construction of single channel pumps. The analysed impellers were cooperated with the same spiral casing where the flow was identified by means of numerical simulation. The obtained results allow to choose appropriate parameters of the pump in terms of the operating point and shape of the characteristic curves.
Optimal design of vortex chamber pump
Authors: Rogovyi A , Korohodskyi V , Khovanskyi S , Hrechka I , Medvediev Y
Published: January 2021

The difficult operating conditions during the pumping of abrasive solid mediums lead to the rapid wear of the mechanical parts of the pumps. The use of jet pumps can significantly increase the reliability and durability of pumping equipment. However, direct-flow jet pumps have low efficiency. The use of the centrifugal force led to the creation of new jet pumps - vortex chamber pumps. Their performance indicators are better than direct-flow jet pump ones. The geometric parameters of the flow channel of the vortex chamber pumps were optimized. The study was carried out experimentally and numerically. Numerical simulation is based on solving the RANS equations with the shear stress transport turbulence model. The geometrical dimensions of the vortex chamber pump with the best performance indicators such as pressure and flow are found. The maximum achievable operating parameters of the vortex chamber pump are analyzed. The comparison of simulation results with experimental data is made.
Experimental and numerical research on influence of winglets arrangement on vortex pump performance
Authors: Machalski A , Skrzypacz J , Szulc P , Błoński D
Published: January 2021

Vortex pumps are widely used in wide range of hydro-transportation applications. Main disadvantage of this type of pump design is low efficiency. Despite ongoing effort to improve vortex impeller performance precise algorithm for their optimal design doesn't exist. One of the ideas is to use winglets (super-vortex) on the tip of the impeller blades. Conducted literature studies have shown that there is not yet clarified principle of winglet design. Authors have performed numerical simulations and measurements for three different arrangements of winglets with varying impeller coverages. From the obtained results recommendation for optimal winglet placement is deducted.
The numerical simulation of the rope vortex creation and the possibilities of its control
Authors: Szulc P , Machalski A , Skrzypacz J , Blonski D
Published: January 2021

The rope vortex is a phenomena which can be observed in many hydraulic machines, especially turbines and pump–turbines. Its creation is based on a non uniform velocity profile characterized by high value of the circumferential component. This phenomena limits the range of operating conditions, which results in reduction of the energy production. The article presents the flow analysis of the hydraulic Francis turbine, where the rope vortex was observed. The structure of the vortex was identify and some solutions were analysed to prevent or reduce the size of multiphase flow.
The measuring system for air mass flow rate determination - difficult measuring conditions - case study
Authors: Tomaszewski A , Przybyliński T , Lackowski M , Krzemiński E , Rogula J , Romanik G , Błoński D
Published: January 2021

Accurate gas flow measurement is required in many industrial applications. In typical circumstances the most reliable option is the use of single-hole orifice flowmeters, which characterize with the simplicity of the construction, lack of moving parts and high accuracy. However, such devices require long straight duct sections in order to perform the proper measurement. Sometimes on existing installations, where the space is limited, there is no possibility to fulfill these requirements. Such problem appeared in power plant in Opole. Multi-hole orifice flowmeters can be a reasonable solution in this particular case. Due to their enhanced resistance to flow disturbance they require shorter duct sections and could provide a correct measurement. The paper presents the results of the numerical analysis of air flow in 6-hole orifice flowmeter. The calculations were performed for the existing duct geometry from power plant in Opole. The orifice pressure drop was estimated for a wide range of Reynolds number. The analysis of the numerical results showed that multi-hole orifice flowmeters can be used in investigated situation. The results of experimental measurements performed in Opole power plant are also included in the paper.
Effect of front impeller seal leakages on centrifugal stage characteristics
Authors: Andrusiak V O , Lugova S O , Medvid S A , Tkach P Yu , Rudenko A A
Published: January 2021

One of the main criteria in designing a pump unit is its economic efficiency and reliability. The efficiency of the pump is impacted by losses which appear in the pump and can be classified into three categories: hydraulic, mechanical and volumetric. Volumetric losses in centrifugal pumps appear in impeller annular seals and throttling gaps of hydraulic balancing devices. Decreasing clearance in annular seals could, undoubtedly, reduce the volumetric losses and lead to an increase in pumps efficiency. In duties close to optimal, a volume of leakages is almost negligible for the main flow passing through the hydraulic passage. On the contrary, impact of leakages becomes significant at underloaded duties. This article deals with effect of leakages in impeller front seal on efficiency and head-capacity curve.
Analytical study of “crosshead – slide rail” wear effect on pump rod stress state
Authors: Ropyak L Y , Velychkovych A S , Vytvytskyi V S , Shovkoplias M V
Published: January 2021

The work presents an analytical study of “crosshead-slide rail” wear effect on stress state of a double piston pump’s rod. The authors proposed an engineering model of pump’s rod stress state and analytically analyzed a pump rod's stress state caused by wear of the “crosshead-slide rail” pair. It was stated, that wear values according to regulations and directive documents can refer to significant values of rod’s residual stresses. The numerical validation of the obtained results was carried out on for drill pump rods, including reinforced functional coatings.
Guided bone tissue regeneration using a hollow calcium phosphate based implant in a critical size rabbit radius defect
Authors: Torbjörn Mellgren , Amela Trbakovic , Andreas Thor , Stina Ekman , Cecilia Ley , Caroline Öhman-Mägi , Petra Hammarström Johansson , Marianne Jensen-Waern , Patricia Hedenqvist
Published: January 2021

Long bone fractures are common and sometimes difficult to treat. Autologous bone (AB), bovine bone and calcium phosphates are used to stimulate bone growth with varying results. In the present study, a calcium phosphate cement (CPC) that previously showed promising grafting capabilities was evaluated for the first time in a long bone defect. A radius defect of 20 mm was created in 20 rabbits. The defect was filled by either a hollow CPC implant that had been manufactured as a replica of a rabbit radius through indirect 3D printing, or by particulate AB as control. Defect filling and bone formation was evaluated after 12 weeks by combining micro computed tomography (μCT) and scoring of 3D images, together with histomorphometry and histology. The μCT and histomorphometric evaluations showed a similar amount of filling of the defect (combining graft and bone) between the CPC and AB group, but the scoring of 3D images showed that the filling in the CPC group was significantly larger. Histologically the AB graft could not be distinguished from the new bone. The AB treated defects were found to be composed of more bone than the CPC group, including reorganised cancellous and cortical bone. Both the CPC and AB material was associated with new bone formation, also in the middle of the defect, which could result in closing of the otherwise critically sized gap. This study shows the potential for an indirectly 3D printed implant in guided bone regeneration in critically sized long bone defects.