bluuebunny/crossref_metadata_2025 huggingface dataset:
New scaling laws predicting turbulent particle pair diffusion, overcoming the limitations of the prevalent Richardson–Obukhov theory
Authors: Malik Nadeem A. , Hussain Fazle
Published: March 2021

Both the evolution of particle pair separation distance l in a turbulent flow and how different length scales affect l are major unresolved challenges. The reigning theory in this topic is that of Richardson and Obukhov (R-O theory). We propose a new theory of pair diffusion in homogeneous, isotropic turbulence hypothesizing that not only structures of size l, but much larger ones also induce significant pair separation—ignored in the R-O theory. We arrive at new scaling laws for the pair diffusivity K, leading to K∼lγ where γ depends on the size of the inertial subrange: for a short inertial subrange, we find from our simulations that K∼l1.44, and for an infinite inertial subrange, we find that K∼l1.556—these relations agree closely with data. We assert that the celebrated “R-O constant” gl is neither physically meaningful nor a constant as universally assumed; our theory leads to two new physically relevant constants: GK for pair diffusivity and Gl for pair separation—which asymptote to GK≈0.73 and Gl≈0.01 at high Reynolds numbers. We find that the particle dispersion is smaller by an order of magnitude compared to R-O prediction; this is significant in many applications such as sprays, and, in particular, the spread of biological contagions (e.g., COVID19) which persist longer and drift farther compared to R-O prediction. We find that the turbulent dispersion does not depend on the fine structure timescale—a striking result which would greatly facilitate turbulent diffusion modeling.
Experimental study on transformation and energy properties of depression internal solitary wave over a bottom step
Authors: Zou Li , Wen Zehua , Sun Tiezhi , Ma Xinyu , Wang Xueyu
Published: March 2021

Waveform deformation and breaking are widespread phenomena when internal solitary waves (ISWs) encounter changing topographies, which have been observed in many parts of oceans. In this study, experiments are performed in a series of combinations of bottom step topographies with different heights and ISWs in different amplitudes within a two-layer stratified fluid system. According to experimental results, the evolution processes of ISWs over the bottom step are classified into four typical regimes as the wave–step interaction varying from weak to strong, which are the transmission regime, transitional regime, breaking regime, and reflection regime, corresponding to the evolution patterns of steady passage, deformation, breaking, and strong reflection, respectively. To describe the intensity of wave–step interaction, a new improved interaction parameter is proposed, which takes both relative amplitude of ISWs and relative topography changes into consideration, and achieved better effectiveness in defining the boundaries between different regimes. In terms of energy properties, with the wave–step interaction becoming stronger, the transmission ratio keeps decreasing throughout all regimes, while the reflection wave starts to appear since the breaking regime and its energy keeps increasing. At the critical point between the breaking regime and reflection regime, the reflection ratio equals the transmission ratio, and the energy loss ratio reaches its maximum.
Thermophoretic collection of virus-laden (SARS-CoV-2) aerosols
Authors: Zhang Xiangzhi , Wang Jing , Wang Chengbo , Lian Zheng , Shi Yong , Ren Yong , Yan Yuying
Published: March 2021

Detecting the existence of SARS-CoV-2 in the indoor atmosphere is a practical solution to track the prevalence and prevent the spread of the virus. In this work, a thermophoretic approach is presented to collect the novel coronavirus-laden aerosols from the air and accumulate to high concentrations adequate for the sensitivity of viral RNA detection. Among the factors, the density and particle size have negligible effects on particle trajectory, while the vertical coordinates of particles increase with the rise in heating source temperature. When the heating temperature is higher than 355K, all of the particles exit the channel from one outlet; thus, the collecting and accumulating of virus-laden aerosols can be realized. This study provides a potential approach to accelerate the detection of SARS-CoV-2 and avoid a false negative in the following RNA test.
Relative motion of two neighboring points on inert and reactive scalar iso-surfaces in homogeneous turbulence
Authors: Dopazo Cesar , Martin Jesus
Published: March 2021

The study of the deformation and rotation of line and surface and volume elements, embedded in a mixing-reaction zone, is supposedly of a paramount importance to comprehend the evolution of inert and chemically reacting species in turbulent flows. This analysis examines the relative motion of two points on adjacent, nonmaterial, propagating, isoscalar surfaces, subject to the flow velocity, v, and the normal displacement speed vector, Sdn (n is the unit vector perpendicular to the isosurface). The methodology of Perry and Chong [“Topology of flow patterns in vortex motions and turbulence,” Appl. Sci. Res. 53, 357–374 (1994)], applied to the velocity gradient tensors of v, A, and Sdn, Aa, serves to characterize this motion. Small-scale flow and displacement topologies clearly emerge from this description. The invariants of these two velocity gradient tensors yield the total rate of change of the normal distance between two isosurfaces, the area stretch factor, the total volumetric dilatation rate, and the nodal or focal features of the motions. The influence of the first invariant on the displacement speed and the chemical depletion is also established. A simple mathematical formalism portrays the time rate of change of an infinitesimal nonmaterial vector, r, joining two points on adjacent isoscalar surfaces within a zone where turbulent mixing of inert and reactive species occurs. Databases of a 3D 5123 DNS of a statistically homogeneous and stationary turbulence with inert and reactive scalars undergoing random mixing in a constant density fluid are examined to illustrate the application of the previous conceptual framework. Small scales are well resolved. Various flow and displacement contributions to the two-point relative velocity components, normal and tangential to the isosurface, are compared to conclude that motions of isoscalar surfaces due to Sdn are, at least, as important as those caused by v. In particular, the additional vorticity, ωa, is one order of magnitude greater than the flow vorticity, ω, and tangential to the isoscalar surfaces, contributing significantly to their folding. While the dynamically passive scalars do not modify the conventional local flow motions, new additional topologies, induced by Aa and typified by its invariants, Pa, Qa, and Ra, appear and affect the displacement speed and the reaction rate. The mass entrainment rate per unit mass into a volume element between two adjacent isosurfaces is given by the first invariant, −Pa, and its influence on the displacement speed and the chemical reaction is explored.
Classical pilot-wave dynamics: The free particle
Authors: Durey Matthew , Bush John W. M.
Published: March 2021

We present the results of a theoretical investigation into the dynamics of a vibrating particle propelled by its self-induced wave field. Inspired by the hydrodynamic pilot-wave system discovered by Yves Couder and Emmanuel Fort, the idealized pilot-wave system considered here consists of a particle guided by the slope of its quasi-monochromatic “pilot” wave, which encodes the history of the particle motion. We characterize this idealized pilot-wave system in terms of two dimensionless groups that prescribe the relative importance of particle inertia, drag and wave forcing. Prior work has delineated regimes in which self-propulsion of the free particle leads to steady or oscillatory rectilinear motion; it has further revealed parameter regimes in which the particle executes a stable circular orbit, confined by its pilot wave. We here report a number of new dynamical states in which the free particle executes self-induced wobbling and precessing orbital motion. We also explore the statistics of the chaotic regime arising when the time scale of the wave decay is long relative to that of particle motion and characterize the diffusive and rotational nature of the resultant particle dynamics. We thus present a detailed characterization of free-particle motion in this rich two-parameter family of dynamical systems.
Analytic calculation and analysis of atomic polar tensors for molecules and materials using the Gaussian and plane waves approach
Authors: Ditler Edward , Kumar Chandan , Luber Sandra
Published: March 2021

The evaluation of atomic polar tensors and Born Effective Charge (BEC) tensors from Density Functional Perturbation Theory (DFPT) has been implemented in the CP2K code package. This implementation is based on a combination of the Gaussian and plane wave approach for the description of basis functions and arising potentials. The presence of non-local pseudo-potentials has been considered, as well as contributions arising from the basis functions being centered on the atoms. Simulations of both periodic and non-periodic systems have been implemented and carried out. Dipole strengths and infrared absorption spectra have been calculated for two isomers of the tripeptide Ser–Pro–Ala using DFPT and are compared to the results of standard vibrational analyses using finite differences. The spectra are then decomposed into five subsets by employing localized molecular orbitals/maximally localized Wannier functions, and the results are discussed. Moreover, group coupling matrices are employed for visualization of results. Furthermore, the BECs and partial charges of the surface atoms of a periodic (101) anatase (TiO2) slab have been investigated in a periodic framework.
Self-sustaining and propagating mechanism of localized wave packet in plane-Poiseuille flow
Authors: Xiao Yue , Tao Jianjun , Zhang Linsen
Published: March 2021

In this Letter, it is revealed that the convection velocity of a localized wave packet in two-dimensional plane-Poiseuille flow is determined by the solitary wave at the centerline of a vortex dipole, which is evinced by subtracting the base flow from the mean flow. The fluctuation component propagates obeying the local dispersion relation of the mean flow and oscillates with a global frequency selected by the upstream marginal absolute instability and, hence, is a traveling wave mode. The vortex dipole provides an unstable region for the fluctuation waves to grow up, and the Reynolds stress of the fluctuation waves leads to streaming components enhancing the vortex dipole. By applying localized initial disturbances, a nonzero wave-packet density is achieved at the threshold state, suggesting a first-order transition.
Waveguide coupled cavity-enhanced light emission from individual carbon nanotubes
Authors: Yamashita D. , Machiya H. , Otsuka K. , Ishii A. , Kato Y. K.
Published: March 2021

We demonstrate an individual single-walled carbon nanotube light emitter integrated onto a microcavity and a waveguide operating in the telecom wavelength regime. Light emission from the carbon nanotube is enhanced at the cavity resonance and is efficiently extracted from the waveguide facet. We have transferred carbon nanotubes to a nanobeam cavity with a dry process, ensuring that an individual carbon nanotube is used. The guided light emission from a chirality-identified single carbon nanotube has a narrow linewidth of less than 1.3 nm and an off-resonance rejection of ∼17 dB. The waveguide-coupled device configuration is compatible with fully integrated on-chip designs and is promising for carbon-nanotube-based photonics.
Diffusion fails to make a stink
Authors: McCaul Gerard , Mershin Andreas , Bondar Denys I.
Published: March 2021

In this work, we consider the question of whether a simple diffusive model can explain the scent tracking behaviors found in nature. For such tracking to occur, both the concentration of a scent and its gradient must be above some threshold. Applying these conditions to the solutions of various diffusion equations, we find that the steady state of a purely diffusive model cannot simultaneously satisfy the tracking conditions when parameters are in the experimentally observed range. This demonstrates the necessity of modeling odor dispersal with full fluid dynamics, where nonlinear phenomena such as turbulence play a critical role.
Giant circular photogalvanic effect of the surface states in an ultra-thin Bi2Se3 nanoplate grown by chemical vapor deposition
Authors: Zhuang Hang , Yu Jinling , Chen Lei , Gu Peng , Chen Yonghai , Liu Yu , Yin Chunming , Lai Yunfeng , Cheng Shuying
Published: March 2021

Ultra-thin Bi2Se3 nanoplates with high crystal quality are obtained by chemical vapor deposition (CVD). A giant circular photogalvanic effect (CPGE) has been observed in the ultra-thin Bi2Se3 nanoplates, which is about one order larger than that previously observed in the thick Bi2Se3 nanoplates grown by CVD and that in the thin Bi2Se3 film grown by molecular beam epitaxy. By applying an ionic liquid gate, the CPGE can be effectively tuned. As the gate voltage increases, the magnitude of the CPGE current decreases, suggesting that the CPGE current under zero gate voltage is dominated by surface states rather than the two-dimensional electron gas (2DEG). It is revealed that as the surface roughness of the Bi2Se3 nanoplates increases, the CPGE decreases and finally reverses the sign, indicating the dominant contribution of the CPGE switches from the top surface states to the 2DEG or the bottom surface states.
Nitrogen–sulfur fertilisation effects on gluten composition and industrial quality in Argentinean bread wheat cultivars differing in apparent sulfur recovery
Authors: Arata Agustín F. , Rogers William J. , Tranquilli Gabriela E. , Arrigoni Adriana C. , Rondanini Deborah P.
Published: March 2021

Increasing wheat yield and grain quality is crucial for achieving profitable production systems. Genotype has an important role in determining potential grain end-use quality, because it defines the protein subunits stored in the endosperm. Nitrogen (N) and sulfur (S) availability modulate the expression of the genotype by determining variations in quantitative gluten composition. The aim of this work was to analyse the responses of grain quality to N and S fertilisation and relate them to the relative quantitative composition of different subunits of gliadins and glutenins in 24 Argentinean bread wheat cultivars differing in apparent S recovery (ASR), cycle length and protein pattern. Two field experiments were conducted in the Humid Pampas of Argentina. Gluten composition was analysed by electrophoresis and densitometry, and grain quality by N/S ratio, protein content, sedimentation test, and alveograms. Most genotypes presented high quality potential according to their pattern of high molecular weight glutenin subunits, although they differed in grain quality performance. Under an environment of low soil fertility (i.e. where the soil has a low capacity to supply N and S), N fertilisation reduced the sedimentation test values at low S level (67 vs 54 mm, on average) and increased this parameter at high S level (62 vs 81 mm, on average), with different responses among genotypes. Also, S fertilisation at high N level increased dough strength by 52% for long cycle genotypes and decreased it by 9% for those of short cycle. Genotypes with contrasting ASR, cycle length and protein pattern modified the responses of baking strength to S fertilisation in different ways (positive, neutral or negative), whereas genotype × N interaction modified the responses only in their magnitude. Outstanding genotypes (e.g. Klein Proteo) were identified according to baking quality stability. We conclude that S fertilisation had a notable effect on baking quality, especially in long cycle genotypes and a low soil-fertility environment, correcting S deficiency at high N availability. ASR was not a useful classificatory trait for predicting grain quality. Instead, the study of variants for the protein subunits coded by particular genes (e.g. Glu-A3, Glu-B3, Glu-D1x and Glu-D1y) that partially determine baking quality should be intensified, in order to optimise genetic improvement in wheat.
Urinary abnormality in mixed connective tissue disease predicts development of other connective tissue diseases and decrease in renal function
Authors: Nishioka Ryo , Zoshima Takeshi , Hara Satoshi , Suzuki Yasunori , Ito Kiyoaki , Yamada Kazunori , Nakashima Akikatsu , Tani Yukiko , Kawane Takashi , Hirata Masayoshi , Mizushima Ichiro , Kawano Mitsuhiro
Published: March 2021

Objective

To clarify the clinical significance of development of urinary abnormality in mixed connective tissue disease (MCTD).

Methods

Forty-one patients with an initial diagnosis of MCTD, followed at five hospitals between April 1, 2000 and December 31, 2013, were included. The relationship between urinary abnormality and various clinical parameters were retrospectively analyzed. Urinary abnormality was defined as proteinuria and/or hematuria detected by urinalysis. Development of other connective tissue diseases (CTDs) was defined as satisfaction of the criteria of each respective disease.

Results

Of 41 patients (34 females, 7 males, mean age at diagnosis 42.2 ± 15.2 years), 16 developed urinary abnormality (UrA(+) patients). The total incidences of development of other CTDs were higher in the UrA(+) patients than UrA(-) (62.5% versus 16.0%, p = .01). In the comparison between UrA(+) and UrA(-) patients, there were no significant differences in follow-up duration or last determined estimated glomerular filtration rate (eGFR), although eGFR decreased more significantly in the UrA(+) patients than UrA(-). (−20.2 ± 17.2 vs −6.1 ± 13.8 ml/min/1.73m2, p = .01; −21.0 ± 18.9 vs −6.7 ± 14.1%, p = .03)

Conclusion

Urinary abnormality during the clinical course in MCTD is predictive of a higher incidence of developing other CTDs. Furthermore, it might also predict long-term renal prognosis in patients with an initial diagnosis of MCTD.
The road from Rous sarcoma virus to precision medicine
Authors: Elemento Olivier
Published: March 2021

In 1911, more than a century ago, Peyton Rous described a curious observation, later explained by a virus named for him that led to the discovery of oncogenes, the modern era of cancer research, and the emergent field of precision medicine (1911. J. Exp. Med. https://doi.org/10.1084/jem.13.4.397).
Experimental determination of the valence band offsets of ZnGeN2 and (ZnGe)0.94Ga0.12N2 with GaN
Authors: Karim Md Rezaul , Noesges Brenton A , Jayatunga Benthara Hewage Dinushi , Zhu Menglin , Hwang Jinwoo , Lambrecht Walter R L , Brillson Leonard J , Kash Kathleen , Zhao Hongping
Published: March 2021

A predicted type-II staggered band alignment with an approximately 1.4 eV valence band offset at the ZnGeN2/GaN heterointerface has inspired novel band-engineered III-N/ZnGeN2 heterostructure-based device designs for applications in high performance optoelectronics. We report on the determination of the valence band offset between metalorganic chemical vapor deposition grown (ZnGe)1−x
Ga2x
N2, for x = 0 and 0.06, and GaN using x-ray photoemission spectroscopy. The valence band of ZnGeN2 was found to lie 1.45–1.65 eV above that of GaN. This result agrees well with the value predicted by first-principles density functional theory calculations using the local density approximation for the potential profile and quasiparticle self-consistent GW calculations of the band edge states relative to the potential. For (ZnGe)0.94Ga0.12N2 the value was determined to be 1.29 eV, ∼10%–20% lower than that of ZnGeN2. The experimental determination of the large band offset between ZnGeN2 and GaN provides promising alternative solutions to address challenges faced with pure III-nitride-based structures and devices.
Physics and technology of time-of-flight PET detectors
Authors: Schaart Dennis R
Published: March 2021

The imaging performance of clinical positron emission tomography (PET) systems has evolved impressively during the last ∼15 years. A main driver of these improvements has been the introduction of time-of-flight (TOF) detectors with high spatial resolution and detection efficiency, initially based on photomultiplier tubes, later silicon photomultipliers. This review aims to offer insight into the challenges encountered, solutions developed, and lessons learned during this period. Detectors based on fast, bright, inorganic scintillators form the scope of this work, as these are used in essentially all clinical TOF-PET systems today. The improvement of the coincidence resolving time (CRT) requires the optimization of the entire detection chain and a sound understanding of the physics involved facilitates this effort greatly. Therefore, the theory of scintillation detector timing is reviewed first. Once the fundamentals have been set forth, the principal detector components are discussed: the scintillator and the photosensor. The parameters that influence the CRT are examined and the history, state-of-the-art, and ongoing developments are reviewed. Finally, the interplay between these components and the optimization of the overall detector design are considered. Based on the knowledge gained to date, it appears feasible to improve the CRT from the values of 200–400 ps achieved by current state-of-the-art TOF-PET systems to about 100 ps or less, even though this may require the implementation of advanced methods such as time resolution recovery. At the same time, it appears unlikely that a system-level CRT in the order of ∼10 ps can be reached with conventional scintillation detectors. Such a CRT could eliminate the need for conventional tomographic image reconstruction and a search for new approaches to timestamp annihilation photons with ultra-high precision is therefore warranted. While the focus of this review is on timing performance, it attempts to approach the topic from a clinically driven perspective, i.e. bearing in mind that the ultimate goal is to optimize the value of PET in research and (personalized) medicine.
Model selection and parameter estimation using the iterative smoothing method
Authors: Koo Hanwool , Shafieloo Arman , Keeley Ryan E. , L'Huillier Benjamin
Published: March 2021

We compute the distribution of likelihoods from the
non-parametric iterative smoothing method over a set of mock
Pantheon-like type Ia supernova datasets. We use this likelihood
distribution to test whether typical dark energy models are
consistent with the data and to perform parameter estimation. In
this approach, the consistency of a model and the data is determined
without the need for comparison with another alternative
model. Simulating future WFIRST-like data, we study type II errors
and show how confidently we can distinguish different dark energy
models using this non-parametric approach.
Sediment and Crustal Structure Beneath East Kalimantan and East Java, Indonesia From Receiver Function
Authors: Bahri Syaiful , Suryanto Wiwit , Ngadmanto Drajat
Published: March 2021

We investigate the sediment and Earth’s crustal structure beneath the East Kalimantan and East Java by modelling the stacked receiver function from six seismic broadband stations belong to the Meteorology, Climatology and Geophysics Agency of Indonesia (BMKG). The calculation of receiver functions from 60 teleseismic earthquake events using iterative time-domain deconvolution method. Inversion result shows a significant variation in the sediment layer thickness from 1 km to 4 km beneath East Java. It is correlated with the South East Java basinal area (station KRK) and the North East Java Basin (station GRJI and BWJI). The sediment layer of about 5 to 10 km beneath East Kalimantan is associated with the Kutai Basin (station SGKI, SMKI, and BKB). Average Sediment layer shear velocity (Vs) beneath all station is observed to be less than 2.31 km/s. Crustal thickness beneath East Java varies between 20 to 40 km and 34 to 50 km beneath East Kalimantan, with average crustal shear wave velocity, Vs 4.60 km/s.
Influence-ladder diagrams as a Method for Teaching and Designing Instrumentation and Automation
Authors: Aurachman Rio
Published: March 2021

Living society is surrounded by various automatic systems. The system design process is one of the important stages in designing an automated system. This indicates the importance of educating engineers capable of designing systems. However, in the learning process, there are difficulties in giving students an understanding of how to compile a ladder diagram with clear steps. There are difficulties in translating the requirements for the electrical system into a ladder diagram. Through this paper, we propose the Influence ladder diagram as a diagram that helps the process of teaching ladder diagram design. This diagram can be used for the teaching process as well as for the actual system design.
PLC Fiddle Software Review as an Instrumentation and Automation Learning Tool
Authors: Aurachman Rio
Published: March 2021

A software is needed that can be used for beginners in learning instrumentation and automation. One of the main diagrams and learning of these two concepts is the Ladder Diagram. For beginners it is easier to use software that is ready to use without having to install the Personal Computer. One software that can be used is PLC Fiddle. Through this paper, we provide an overview of what features are in the PLC fiddle. And explained how to use these features for learning instrumentation and automation, for beginners. We provide several Online Video Tutorials for learning PLC Fiddle.
Effect of PVDF composition in activated carbon derived from chicken feather on electrical properties
Authors: Hastuti E , Irfana I
Published: March 2021

Chicken feathers are agricultural wastes and become pollutants because of the resistance to protease degradation. Feathers contain a fibrous protein called keratin and potentially for producing activated carbon. In many applications, activated carbon is made of composites with poly (vinylidene fluoride) PVDF to improve its function. This research was carried out to study the effect of PVDF composition on activated carbon derived from chicken feathers on electrical properties. Besides evaluating changes in chemical structure and surface morphology, composites were tested using FTIR and digital microscopy. An addition of PVDF improves its dielectric properties. But the higher composition, causing agglomeration that inhibits polarization. The dielectric constant and conductivity of composite with 15 wt% PVDF are 1950 and 1.45 x 10−5 S/cm at 1 kHz, larger than another composition.
Structure boron rich type b25c space group P-4 2 m the lattice is accentric primitive tetragonal laue symmetry 4/mm
Authors: Fajrah M C , Soegijono B , Susetyo F B
Published: March 2021

Abstarct. A reaction between carbon and boric acid has been carried out through a solid state reaction. The sample is heated at 400oC. Characterization tests were carried out with X-Ray Diffraction (XRD) equipment and GSAS analysis. Based on the analysis of the results of the sample has the structure of boron rich type B25C initial lattice parameters a = b = 8.753 Å, c = 5, 093Á after refine chi 1.8 a = b = 8.730469Á c = 5.827706Á, with angles α = β = γ = 90° Space Group P - 4 2 m the lattice is accentric primitive tetragonal laue symmetry 4/mm multiplicity of a general site is 8 at the atomic position (x, y, z) B1 B2 B3 B4 B5 B7 B8 B9 B10 B11 B12 B13 B14 B15 B25.
Influence Of Heat Treatment On Crystal Structure And Corrosion Properties Of Co-Cr-Mo-Al Alloy In Simulated Body Fluid Solution
Authors: Eka Perkasa Daniel , Qonita Aliya , Soegijono Bambang
Published: March 2021

One of the biocompatibility properties of cobalt alloys as a biomaterial is the corrosion resistance of the alloy to the biological environments such as Simulated Body Fluid (SBF). Cobalt alloys have two dominant crystal structures the FCC and HCP structures. The Co-Cr-Mo-Al alloy were subjected to the heat treatment at a temperature of 1000 °C, with various holding time, 4, 6, and 8 hours. Observation of the crystal structure of the alloy was conducted by using x-ray diffraction and the corrosion resistance was carried out by the voltammetry method, Cyclic Voltammetry (CV) and Linear Sweep Voltammetry (LSV) in Simulated Body Fluid (SBF) at a temperature of 37 °C. From x-ray diffraction pattern, it is known that heat treatment increases the crystallite size of the alloy and alter the lattice parameters. The variations in the holding time of heating lead increase the concentration of the Face Centre Cube (FCC) crystal structures in the alloy. Observation of Cyclic Voltammetry show that the reaction of the formation of passive layers takes place spontaneously in an SBF environment. LSV data were used to determine the changes density current of corrosion of alloy. A low corrosion rate is found in alloy that untreated heat. It can conclude that heat treatment with different holding time affect on the crystal structure and corrosion properties of Co-Cr-Mo-Al alloys in the SBF solution.
Effects of gold on the structure and electrochemical behavior of lead-gold composite in different temperatures sulfuric acid
Authors: Suryandhito H , Soegijono B , Darma S
Published: March 2021

Lead is still dominantly used as the main material for lead-acid batteries electrodes and active materials. Lead-gold composites were made in efforts to improve the performance of the active materials component for lead-acid batteries. The electrochemical behavior of Pb-Au composite in sulfuric acid solution (H2SO4) were investigated. Au was chosen as the reinforcement material for lead composite because of its high electrical conductivity and its resistance to chemical reaction which is important to resist the formation of lead sulfate (PbSO4) crystal on the surface of electrodes. Lead-gold composite were made by mixing lead powder and auric chloride (AuCl3) solution. The fabrication of Pb-Au composites was done by mixing Pb powders and auric chloride (AuCl3) solution and using hot-press method. Material characterizations were performed using X-ray fluorescence technique to investigate material composition and X-ray diffraction technique to investigate material structure. The electrochemical properties of Pb-Au composites were investigated by electrochemical polarization testing, specifically linear sweep voltammetry technique (LSV) in H2SO4 solution with various solution temperature at 10° C, 25° C, and 40° C to simulate common active vehicle condition. The results show that the crystal structure of lead-gold composites is face-centered cubic (FCC) structure. Also, the addition of Au lower the Icorr and shift the Ecorr to a more cathodic potential.
Multistep sintering: its role on density, phase homogeneity, microstructure and electrical properties of (1-x-y)BaTiO3-xPbZrO3-yNaVO3 System
Authors: Absa M , Latief F , Suasmoro S
Published: March 2021

Barium Titanate synthesized by the oxalate coprecipitation method was doped by other perovskite-based material PbZrO3 and NaVO3 to obtain a system of (1-x-y)BaTiO3-xPbZrO3-yNaVO3 with x = 0.15 and y = 0.025. TGA characterization shows an important weight loss that starts at 400°C and finished at 650°C. XRD analysis of calcined powder at 650°C shows that the samples mostly consist of single-phase BaTiO3 perovskite. Sintering process was carried out in two ways; first, a single step sintering up to 1250°C for 2 hours shows increasing secondary phases, until the BaTiO3 phase becomes the minority. Secondly, multistep sintering starting at 1050°C, holding for 2 hours, down to room temperature, and then repeated with similar processes for 1150°C and 1250°C. Characterizations including XRD, SEM for microstructure, and permittivity analysis of the sample after this thermal treatment shows that the majority phase is BaTiO3 with minor secondary BaVO2.9 phase and its electrical properties are enhanced.
Variation of etching time on formation of porous silicon on p-type Si (111) using electrochemical anodization method
Authors: Sehati  , Wijayanti S , Suryana R
Published: March 2021

Porous silicon (PSi) has been formed on p-type Si (111) substrates using electrochemical anodization method. Silicon surfaces were anodized in HF (40%) dan ethanol (96%) solution with a ratio of 1:1. Anodization time was varied at 6, 8, 10 and 12 min with current density was maintained constant at 80 mA/cm2. Platinum foil was as a cathode while silicon was as an anode with a distance of 5 cm. The optical reflectance of the sample was determined using UV-Vis Spectrophotometer and surface morphology was observed using AFM. AFM’s images could determine the depth, width and roughness of PSi. The reflectance of PSi on Si (111) decreased with increasing the etching time. It indicated that many photons were trapped inside the porous. AFM images confirmed that the depth, the width, and the roughness of PSi increased with the increasing of the etching time. It is considered that the etching direction worked in the vertical and horizontal ways.
Natural magnetite characterization from beach sand prepared by using planetary ball milling
Authors: Jalil Zulkarnain , Novita Sari Eva , Ismail Ismail , Muhammad  , Nizar Machmud M. , Handoko Erfan
Published: March 2021

In this paper, the mineral composition and magnetic behavior of nano magnetite (Fe3O4) extracted from beach were studied. The beach sand was collected from the Gampong Dayah coastal area, Banda Aceh and prepared by mechanical alloying method. The mineral compositions were investigated by XRD and XRF analysis tests. The XRF test showed that the sand mostly contain Fe3O4 in association with other isomorphous impurities, such as SiO2, TiO2, Al2O3 and some others minor minerals in varying proportions. Compare to XRD results, it was consistent with XRF, the phase compositions are mainly magnetite (Fe3O4). The XRD revealed that magnetite is the major mineral components in the Syiah Kuala sand. The electron microscope (SEM) identification showed the fine crystalline structure and the main morphology was micro-crystalline or agglomerate forms. The magnetic properties of the samples after milling showed there has been increasing in coercivity (Hc) and remanent (Br), while magnetic saturation (Ms) was decreased.
The effect of addition of vegetable waste on microbial fuel cell performance
Authors: Mulyono T , Misto  , Nasifatul S M
Published: March 2021

In the past few years the fuel cell has become the centre of attention of the scientific community for the possibility of converting organic waste into electricity directly through redox reactions with the help of bacteria or enzymes. The purpose of this study was to determine the value of MFC performance due to the influence of adding vegetable waste. The soil media used is obtained from agricultural areas. The system used in the MFC is a single chamber of a vessel with a volume of 500 mL. The types of electrodes used are carbon fibres with anode thickness of 0.5 cm and cathode 1.0 cm, as well as anode diameter of 8.0 cm and cathode 8.5 cm. Vegetable wastes were given 5 mg / L each in the MFC single chamber. The results showed that the highest power was generated from a microbial fuel cell with spinach vegetable waste. The power produced is 250 mW (49 mW/cm2). The incubation period for MFC can reach 30 days. Variation of the second rinse with a concentration of 499 ppm will have a pH value having a pretty good linear correlation of 0.9536 to the more electric power generated. The power produced by the MFC 6 series circuit is 1.00 mW, while the power generated by the parallel series is 0.831mW.
Cyclotron-based rhenium-186 production using proton beam of up to 50 MeV
Authors: Kambali I
Published: March 2021

Rhenium-186 (186Re) radioisotope has been suggested for palliative radiotherapy of bone metastic cancer patients and radiosynovectomy in nuclear medicine. Currently 186Re has been mostly produced using neutron activation in nuclear reactors, whereas cyclotron-based production has not been well explored. In this paper, we theoretically propose cyclotron-based proton beams of up to 50 MeV for 186Re production. By Employing the TALYS 2017 codes, we calculated nuclear cross-section for (p, n) nuclear reaction and then buit Matlab codes for the End-of-Bombardment (EOB) yield calculations of 186W(p, n)186Re nuclear reaction while the predicted impurities were calculated for (p, 2n), (p, np), (p,α) and (p, d) nuclear reactions respectively. The TALYS calculated cross-sections indicated that the threshold energy for 186W(p, n)186Re nuclear reaction is 8 MeV. The maximum calculated EOB yield for 186W(p, n)186Re reaction at 50 MeV was 93.64 kBq/µAh which agreed with experimental data published elsewhere. The threshold energies for the (p,2n), (p, np), (p,α) and (p, d) were 7.58, 7.23, 2.0 and 4.99 MeV respectively. In addition, two radionuclides, i.e. 185W and 183mRe as well as two stable isotopes, i.e. 185Re and 184W were predicted to be the main impurities in the 186Re production. This study can be used as a reference for future 186Re production when proton beams of up to 50 MeV are employed.
Electric Field Investigation for Ag Nanosquare Blood Cancer Sensor with Finite Difference Time Domain (FDTD) Simulation
Authors: Farahdina U , Zulfa V Z , Firdhaus M , Endarko E , Rubiyanto A , Nasori N
Published: March 2021

Blood carrying more leukocytes can induce differences in electrical and magnetic properties. This work describes the effect of leukocyte concentration on the distribution of electric fields. The finite difference time domain approach of electric field distribution using normal blood and leukocyte has been analyzed. The electric field in the blood and leukocytes have the same peak at a wavelength of 400nm. Ag nanosquare with dimensions of 350×350nm2 in blood and leukocyte medium has a different maximum electric field of 7.35 × 10−7V/m with a peak wavelength difference of 0.22nm. The results of this work are beneficial to expected and provide an interpretation of blood cancer detection using an Ag nanosquare arrays sensor.
Supersymmetric solutions of D-dimensional dirac equation for woods-saxon potential in minimal length formalism
Authors: Suparmi A , Akbar J , Cari C
Published: March 2021

We obtain the energy eigenvalues and radial wave functions of the D-Dimensional Dirac equation in the case of spin symmetry for Woods-Saxon potential in minimal length formalism. The radial part of the D-Dimensional Dirac equation is solved by applied the supersymmetric quantum mechanics method using the Pekeris approximation to deal with the centrifugal term. The behavior of bound-state energy eigenvalues versus dimension and also quantum number is discussed for various minimal length parameters.
Research on risk prevention and control strategy of power grid CPS system based on intrusion tolerance
Authors: Li Zhanjun , Hu Bo , Lu Tianqi , Wei Yuxi , Zhao Qingqi , Duan Zhiyuan
Published: March 2021

In this paper, an information-physical risk prevention and control framework based on intrusion tolerance technology is proposed, which is a multi-stage in-depth defense system for the risk interaction mechanism and evolution process in the power information-physical fusion system, the aim of this paper is to improve the survivability of the system under attack and minimize the loss caused by the risk through multi-phase defense strategy. At the same time, according to the phase characteristics of risk propagation in CPS, a safe operation state transition model considering intrusion tolerance is established. In order to contain the critical failure events in the risk evolution process of the information-physics fusion system, according to the risk development characteristics of the information-physics system under attack, this paper presents a self-organized critical state identification method, which integrates the characteristics of physical network power flow and information network traffic flow, in order to identify the critical nides that make CPS system enter the self-organized critical state under network attack. Finally, according to the characteristics of CPS dependent network structure and the self-organized critical characteristics of risk evolution, the protection strategies of strengthening the protection of key nodes, adjusting the coupling state of dependent edges and adding autonomous nodes are formulated, by considering the decision-making model of risk prevention and control strategy in the game of attack and defense, the current defense resources are reasonably allocated.
Effect of different arbuscular mycorrhizal fungi on Cadmium absorption of Sedum aizoon L
Authors: Peng Sihan , Ma Yaoqing , Zhong Yufeng , Xia Tianqi , He Zhongqun
Published: March 2021

In order to investigate the effect of different arbuscular mycorrhizal (AM) fungi on Cadmium (Cd) uptake of Sedum aizoon L.. Under Cd stress, five AM fungi (GMA, GM, GV, BEG167, BEG168) were inoculated to Sedum aizoon L. at 10 mg⋅kg−1 Cd concentration, and the growth, physiological indexes and Cd accumulation of Sedum aizoon L. under different treatments were measured. The results showed that: GMA fungi significantly increased the growth and biomass of Sedum aizoon L.; GMA and GM fungi significantly increased the proline content of Sedum aizoon L.; GMA and BEG168 fungi significantly reduced the Cd content of roots, stems and leaves. Therefore, under the Cd stress, inoculating GMA fungi can not only significantly improve the growth, biomass, but also significantly reduce the content of Cd in various parts of Sedum aizoon L., which has a certain value in practical production.
Construction Pollution Prevention Measures and Effect Analysis of Engineering Projects
Authors: Wei Guoan
Published: March 2021

By tracking and monitoring the implementation of the construction pollution prevention and control measures for the phase-three engineering project, the pollution situations before and after the construction pollution prevention and control measures are compared. The analysis shows that after carrying out the pollution prevention measures, the control effect of air quality, noise, construction waste, and water pollution has been significantly improved.
Analysis on Electromagnetic Environment from 750 kV Transformer Substation in Gansu Power Network
Authors: Gao Shigang , Chang Guohua , Chen Honggang , Li Wei
Published: March 2021

In order to understand the influence of 750 kV power transmission and transformation project on electromagnetic radiation of surrounding environment, the data of electric field intensity, magnetic field intensity and noise from 750 kV substation equipment transmission and transformation system in some areas of Gansu Province were monitored and analyzed. The results showed that the areas near circuit breaker, switch and reactance in the power transmission system were the main areas producing high electric field intensity. The electric field intensity near the circuit breaker is the highest in substation equipment, with the average value of 12.40 ± 1.25 kV/m, while the main noise producing area is near the reactor. The study could provide scientific basis for environmental assessment and prevention of ultrahigh voltage power transmission projects.
Study on upgrading and engineering design of leachate treatment facilities in a landfill in Beijing
Authors: Ke Li , Lu Yan
Published: March 2021

This paper systematically introduces the technical route and engineering design practice of upgrading and reconstruction of a landfill leachate treatment station in Beijing. The Water balance tank+ Two-stage A/O external MBR+ Nanofiltration+ Reverse osmosis process is adopted to realize that the effluent quality of landfill leachate treatment meets the requirements of B emission limits in Table 1 of Beijing local standard DB11/307-2013, which can provide reference for engineering design and research on the selection of technical route for upgrading landfill leachate treatment.
Research progress on treatment technology of waste incineration fly ash
Authors: Liu Zhe , Ren Xiaohan
Published: March 2021

Incineration is an important way of garbage disposal. The fly ash is a kind of hazardous waste, which is rich in heavy metals, dioxins and other harmful substances. At present, the main treatment and disposal technologies of fly ash include stabilization and solidification, chemical treatment, safe landfill and resource treatment. At present, the main treatment technologies have their own advantages and disadvantages. This paper summarizes the treatment and disposal methods of fly ash based on the research status at home and abroad. Among them, resource-based treatment is the main research direction in the future. It is urgent to study clean and efficient treatment technology suitable for China.
Design of Yunnan Province Soil Environmental Quality Monitoring and Analysis Platform Based on WebGIS
Authors: Xu Wenjie , Liang Hong , Luo Wei , Kang Xiaolin
Published: March 2021

The state and government departments will produce a large amount of soil survey data in the process of soil environmental pollution investigation. The format of soil data has diversified and multi-scale spatial characteristics. Due to the lack of a unified soil environmental pollution management platform in Yunnan Province, the storage of soil survey data is disorderly and messy. The data cannot be well-informed and scientifically analyzed, resulting in the inability to provide accurate and comprehensive soil environmental quality for all levels of government management data. In order to effectively solve this problem, taking soil heavy metal pollution survey sampling points in Yunnan Province as an example, this paper uses web geographic information systems (GIS) technology to design a set of soil environmental monitoring and analysis platforms that describe data sources, data collection, data analysis and visualization. The platform has established a scientific and rigorous data analysis method, which can uniformly convert and store historically scattered data and conduct unified management and analysis of survey data.
Optimization of Extraction Process for Total Flavonoids of Lycium Barbarum by Response Surface Methodology
Authors: Na An , Lihui Wang
Published: March 2021

To optimize the Soxhlet extraction technology for total flavonoids of lycium barbarum by response surface methodology (RSM). Methods: On the base of single factor experiments, liquid to solid ratio, particle size and extraction time were selected as the main factors, with the extraction capacity as the response values, RSM was used to optimize the Soxhlet extraction process. Results: Optimal parameters were as follows: the particle size was 70 meshes. liquid to solid ratio was 17.59 ml/g, extraction time was 2.47hours. Under these conditions, the extraction capacity was 14.57 mg/g on average, and the experimental values agreed with the predicted values. Conclusion: This optimized extraction technology for total flavonoids of lycium barbarum is stable, feasible and reasonable, and with high accuracy, which could could guide the applications of production.