bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating shock melting of metals through time-resolved x-ray diffraction of cerium
Authors: Beason M. T. , Jensen B. J. , Branch B.
Published: October 2020

Time-resolved x-ray diffraction (XRD) was used to examine the behavior of Ce under shock loading to stress states up to 22 GPa that span the shock-melt transition. Experiments reported here observed Ce held at a steady state for ∼500 ns prior to being uniaxially released to ambient pressure. Time-resolved XRD shows a constant diffraction pattern over the duration of the steady state with rapid solidification occurring on release. Cerium was found to remain crystalline as Poisson's ratio (ν) increases in the α-phase with incipient melt observed in XRD once ν reaches 0.5. Diffraction results along with sound speed measurements limit melt completion to be between 12 and 14 GPa, significantly lower than previously expected. The XRD results add confidence to previous methods used to define incipient melt and help to define a method to constrain the melt region along the Hugoniot independent of a light source.
Effects of density and composition on the properties of amorphous alumina: A high-dimensional neural network potential study
Authors: Li Wenwen , Ando Yasunobu , Watanabe Satoshi
Published: October 2020

Amorphous alumina (a-AlOx), which plays important roles in several technological fields, shows a wide variation of density and composition. However, their influences on the properties of a-AlOx have rarely been investigated from a theoretical perspective. In this study, high-dimensional neural network potentials were constructed to generate a series of atomic structures of a-AlOx with different densities (2.6 g/cm3–3.3 g/cm3) and O/Al ratios (1.0–1.75). The structural, vibrational, mechanical, and thermal properties of the a-AlOx models were investigated, as well as the Li and Cu diffusion behavior in the models. The results showed that density and composition had different degrees of effects on the different properties. The structural and vibrational properties were strongly affected by composition, whereas the mechanical properties were mainly determined by density. The thermal conductivity was affected by both the density and composition of a-AlOx. However, the effects on the Li and Cu diffusion behavior were relatively unclear.
Reduced density matrices of Richardson–Gaudin states in the Gaudin algebra basis
Authors: Fecteau Charles-Émile , Fortin Hubert , Cloutier Samuel , Johnson Paul A.
Published: October 2020

Eigenvectors of the reduced Bardeen–Cooper–Schrieffer Hamiltonian have recently been employed as a variational wavefunction ansatz in quantum chemistry. This wavefunction is a mean-field of pairs of electrons (geminals). In this contribution, we report optimal expressions for their reduced density matrices in both the original physical basis and the basis of the Richardson–Gaudin pairs. Physical basis expressions were originally reported by Gorohovsky and Bettelheim [Phys. Rev. B 84, 224503 (2011)]. In each case, the expressions scale like O(N4), with the most expensive step being the solution of linear equations. Analytic gradients are also reported in the physical basis. These expressions are an important step toward practical mean-field methods to treat strongly correlated electrons.
Ferroelastic domain walls as templates for multiferroic devices
Authors: Salje Ekhard K. H.
Published: October 2020

Ferroelastic domain walls are typically twin interfaces. They contain a multitude of emerging properties, including (super-)conductivity, polarity, optically activity, and photovoltaic properties and may contain a number of magnetic properties even when there is no magnetic element in the ferroelastic matrix. Current progress to determine these properties is reviewed. Local wall properties change a little if the domain walls are deformed, but external fields can shift the location of the wall. Mobile domain boundaries carry with them the locus of any emerging property. The double flexibility of functional domain walls and the possibility to move domain boundaries provide a new design concept for device manufacturing. Some potential avenues for device designs are discussed.
Quantifying production of hot firebrands using a fire-resistant fabric
Authors: Adusumilli Sampath , Hudson Tyler , Gardner Nathan , Blunck David L.
Published: October 2020

Identifying the number of firebrands generated during wildfires is an important aspect of understanding their propagation. A key challenge in quantifying the number of firebrands released is to distinguish those that are ‘hot’ and could lead to further fire spread from the total number released. Recently, a fire-resistant fabric was used to quantify the number of ‘hot’ firebrands released from different species of trees (based on char marks). However, information regarding the temperatures of the firebrands leaving the char marks was not reported. In this paper, we demonstrate a methodology for characterising the charring behaviour of fire-resistant fabrics and illustrate how the fabric can be used for firebrand generation studies. The results established a minimum temperature (300°C) for char mark formation. The sensitivities of charring to temperature and time of contact between the fabric and heater are reported. A first-order analysis estimated the char mark area to be an exponential function of the temperature, power input and time of exposure. Illustrating the usefulness of the approach, the fire-resistant fabric was deployed to study hot firebrand production rates for trees treated with and without a fire retardant. The number of hot firebrands produced was lower for trees coated with fire retardant.
Harvesting predators: simulation of population recovery and controlled harvest of saltwater crocodiles Crocodylus porosus
Authors: Fukuda Yusuke , Webb Grahame , Edwards Glenn , Saalfeld Keith , Whitehead Peter
Published: October 2020

Abstract ContextThe population of saltwater crocodiles, Crocodylus porosus, in the Northern Territory, Australia, has been recovering from a period of intensive, unregulated harvest (1945–1971) since protection in 1971. Consequently, the management goal is shifting from restoring a seriously depleted population to managing an abundant population through controlled harvests for both commercial purposes and public safety. AimsWe conducted this study to (1) examine whether the controlled harvest of eggs and adults since protection has had an adverse effect on population size and structure, and (2) explore the effect of future harvest scenarios on population size and structure by adjusting harvest levels of both eggs and adults. MethodsOn the basis of 40 years of population monitoring data and knowledge of population attributes from previous research, we developed density-dependent, structured matrix population models to explore our aims. Key resultsThe models supported that the depleted population recovered rapidly under protection and that the harvest rates since protection were benign. The model estimated the 2017 harvested population, 46 years after protection, to be ~102000 non-hatchlings (>0.6m crocodiles), of which 42.2% are large (>2.1m total length) individuals. This is similar to the estimated population before the period of intensive, unregulated harvest. Like other crocodilians, the harvest simulations showed that the viability of the population is highly sensitive to adult survival rates. The estimated population should be able to sustain an annual harvest of up to 135500 eggs if the harvest of large crocodiles remains small (<500 per year). ConclusionsAlthough egg harvest has little impact on population size and structure, population size is sensitive to adult harvest. ImplicationsCrocodile populations are highly sensitive to adult survival, which needs to be taken into account when considering future harvest scenarios.
Effective potential of scalar–tensor gravity
Authors: Arbuzov Andrej , Latosh Boris
Published: October 2020

Effective potential of a scalar field induced by weak gravity is studied. The set of operators providing the leading contribution and preserving the second order of field equations is found. It is shown that only a mass term and a specific Brans–Dicke-like interaction are relevant within such a setup. An explicit form of the potential is found. The model has room for a natural inflationary scenario similar to the well-known case of the Starobinsky inflation. Possible implications for the standard model are highlighted.
Structure, reactions, and electronic spectra of the rare gas cyanohydrides and isocyanohydrides, HRgCN and HRgNC (Rg = Xe or Rn)
Authors: van Hoeve Miriam D , Klobukowski Mariusz
Published: October 2020

The low-energy electronic excitations of HRgCN and HRgNC (Rg = Xe, Rn) were computed at the TDDFT level of theory, both in the gas phase and in xenon cluster. It was found that the most prominent peak in the spectra was due to the highest occupied molecular orbital (HOMO) to lowest unoccupied molecular orbital (LUMO) transition (∼6 eV for HRgCN and ∼4.5 eV for HRgNC). Cluster confinement brought about bathochromic shifts in the spectra and better agreement with experiment for HXeCN. The effects of spin–orbit coupling (SOC) in the heavier Rn systems were investigated: for HRnCN, SOC red-shifted the HOMO–LUMO peak, while it blue-shifted the HOMO–LUMO peak for HRnNC. Geometry optimizations were carried out for the HRgCN and HRgNC systems to locate minima and transition states for dissociation and isomerization. Effects of isotopic substitution on reaction rates were predicted. A new model core potentials basis set was introduced and effectiveness of several pseudopotential basis sets was studied.
Effect of substrate symmetry on the orientations of MoS2 monolayers
Authors: Pan Shuangyuan , Yang Pengfei , Zhu Lijie , Hong Min , Xie Chunyu , Zhou Fan , Shi Yuping , Huan Yahuan , Cui Fangfang , Zhang Yanfeng
Published: October 2020

Two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs) are promising platforms for developing next-generation electronic and optoelectronic devices due to their unique properties. To achieve this, the growth of large single-crystal TMDs is a critical issue. Unraveling the factors affecting the nucleation and domain orientation should hold fundamental significance. Herein, we design the chemical vapor deposition growth of monolayer MoS2 triangles on Au(111) and Au(100) facets, for exploring the substrate facet effects on the domain orientations. According to multi-scale characterizations, we find that, the obtained triangular MoS2 domains present two preferential orientations on the six-fold symmetric Au(111) facet, whereas four predominant orientations on the four-fold symmetric Au(100) facet. Using on-site scanning tunneling microscopy, we further reveal the preferred alignments of monolayer MoS2 triangles along the close-packed directions of both Au(111) and Au(100) facets. Moreover, bunched substrate steps are also found to form along the close-packed directions of the crystal facets, which guides the preferential nucleation of monolayer MoS2 along the step edges. This work should hereby deepen the understanding of the substrate facet/step effect on the nucleation and orientation of monolayer MoS2 domains, thus providing fundamental insights into the controllable syntheses of large single-crystal TMD monolayers.
Unveiling the interplay between induced native defects and room temperature magnetic ordering in titanium deficient disordered-TiO2 nanoparticles
Authors: Dhakshinamoorthy Jayaseelan , Srivastava Sachin Kumar , Mishra Durgamadhab , Pullithadathil Biji
Published: October 2020

Understanding the origin of magnetic ordering in an undoped semiconductor with native defects is an open question, which is being explored actively in research. In this investigation, the interplay between magnetic ordering and excess induced native defects in undoped anatase TiO2 nanoparticles is explained using an experimental and theoretical approach. It is demonstrated that structurally disordered TiO2 nanoparticles with a high concentration of native defects such as titanium interstitials and oxygen vacancies are synthesized using controlled atmospheric rapid cooling (i.e. quenching) process. The structural disorders in the lattice have been examined using various spectroscopic and microscopic analyses revealed the existence of Ti deficiency in both pristine and quenched TiO2 nanoparticles. A possible origin of magnetic ordering in titanium deficient anatase TiO2 system is elucidated based on first-principle calculations. It was found that the overall magnetic moment of Ti deficient TiO2 system is determined by the distance between Ti interstitials and its neighboring vacancies (i.e. either V
Ti or V
Os). However, quenched TiO2 nanoparticles possess excess Ti interstitials, Ti and O vacancies and therefore the net magnetic moment of the system is reduced due to anti-ferromagnetically coupled neighboring Tilattice ions.
Self-powered, ultra-high detectivity and high-speed near-infrared photodetectors from stacked–layered MoSe2/Si heterojunction
Authors: Xu Yan , Ma Yuanming , Yu Yongqiang , Chen Shirong , Chang Yajing , Chen Xing , Xu Gaobin
Published: October 2020

Photodetectors based on high-performance, two-dimensional (2D) layered transition metal dichalcogenides (TMDCs) are limited by the synthesis of larger-area 2D TMDCs with high quality and optimized device structure. Herein, we report, for the first time, a uniform and stacked–layered MoSe2 film of high quality was deposited onto Si substrate by using the pulsed laser deposition technique, and then in situ constructed layered MoSe2/Si 2D–3D vertical heterojunction. The resultant heterojunction showed a wide near-infrared response up to 1550 nm, with both ultra-high detectivity up to 1.4 × 1014 Jones and a response speed approaching 120 ns at zero bias, which are much better than most previous 2D TMDC-based photodetectors and are comparable to that of commercial Si photodiodes. The high performance of the layered MoSe2/Si heterojunction can be attributed to be the high-quality stacked–layered MoSe2 film, the excellent rectifying behavior of the device and the n-n heterojunction structure. Moreover, the defect-enhanced near-infrared response was determined to be Se vacancies from the density functional theory (DFT) simulations. These results suggest great potential of the layered MoSe2/Si 2D–3D heterojunctions in the field of communication light detection. More importantly, the in situ grown heterojunctions are expected to boost the development of other 2D TMDCs heterojunction-based optoelectronic devices.
Capsaicin-loaded solid lipid nanoparticles: design, biodistribution, in silico modeling and in vitro cytotoxicity evaluation
Authors: Kunjiappan Selvaraj , Sankaranarayanan Murugesan , Karan Kumar Banoth , Pavadai Parasuraman , Babkiewicz Ewa , Maszczyk Piotr , Glodkowska-Mrowka Eliza , Arunachalam Sankarganesh , Ram Kumar Pandian Sureshbabu , Ravishankar Vigneshwaran , Baskararaj Suraj , Vellaichamy Sivakumar , Arulmani Lalitha , Panneerselvam Theivendren
Published: October 2020

Lower doses of capsaicin (8-methyl-N-vanillyl-6-nonenamide) have the potential to serve as an anticancer drug, however, due to its pungency, irritant effect, poor water solubility and high distribution volume often linked to various off-target effects, its therapeutic use is limited. This study aimed to determine the biodistribution and anticancer efficacy of capsaicin loaded solid lipid nanoparticles (SLNs) in human hepatocellular carcinoma in vitro. In this study, SLNs of stearic acid loaded with capsaicin was formulated by the solvent evaporation-emulsification technique and were instantly characterized for their encapsulation efficiency, morphology, loading capacity, stability, particle size, charge and in vitro drug release profile. Synthesized SLNs were predominantly spherical, 80 nm diameter particles that proved to be biocompatible with good stability in aqueous conditions. In vivo biodistribution studies of the formulated SLNs showed that 48 h after injection in the lateral tail vein, up to 15% of the cells in the liver, 1.04% of the cells in the spleen, 3.05% of the cells in the kidneys, 3.76% of the cells in the heart, 1.31% of the cells in the lungs and 0% of the cells in the brain of rats were determined. Molecular docking studies against the identified targets in HepG2 cells showed that the capsaicin is able to bind Abelson tyrosine-protein kinase, c-Src kinase, p38 MAP kinase and VEGF-receptor. Molecular dynamic simulation showed that capsaicin-VEGF receptor complex is highly stable at 50 nano seconds. The IC50 of capsaicin loaded SLNs in HepG2 cells in vitro was 21.36 μg × ml−1. These findings suggest that capsaicin loaded SLNs are stable in circulation for a period up to 3 d, providing a controlled release of loaded capsaicin and enhanced anticancer activity.
Model-based dual-energy tomographic image reconstruction of objects containing known metal components
Authors: Liu Stephen Z , Cao Qian , Tivnan Matthew , Tilley II Steven , Siewerdsen Jeffrey H , Stayman J Webster , Zbijewski Wojciech
Published: October 2020

Dual-energy (DE) decomposition has been adopted in orthopedic imaging to measure bone composition and visualize intraarticular contrast enhancement. One of the potential applications involves monitoring of callus mineralization for longitudinal assessment of fracture healing. However, fracture repair usually involves internal fixation hardware that can generate significant artifacts in reconstructed images. To address this challenge, we develop a novel algorithm that combines simultaneous reconstruction-decomposition using a previously reported method for model-based material decomposition (MBMD) augmented by the known-component (KC) reconstruction framework to mitigate metal artifacts. We apply the proposed algorithm to simulated DE data representative of a dedicated extremity cone-beam CT (CBCT) employing an x-ray unit with three vertically arranged sources. The scanner generates DE data with non-coinciding high- and low-energy projection rays when the central source is operated at high tube potential and the peripheral sources at low potential. The proposed algorithm was validated using a digital extremity phantom containing varying concentrations of Ca-water mixtures and Ti implants. Decomposition accuracy was compared to MBMD without the KC model. The proposed method suppressed metal artifacts and yielded estimated Ca concentrations that approached the reconstructions of an implant-free phantom for most mixture regions. In the vicinity of simple components, the errors of Ca density estimates obtained by incorporating KC in MBMD were ∼1.5–5× lower than the errors of conventional MBMD; for cases with complex implants, the errors were ∼3–5× lower. In conclusion, the proposed method can achieve accurate bone mineral density measurements in the presence of metal implants using non-coinciding DE projections acquired on a multisource CBCT system.
Influence of surface parameters on dielectric-barrier discharges in argon at subatmospheric pressure
Authors: Stankov M , Becker M M , Bansemer R , Weltmann K-D , Loffhagen D
Published: October 2020

The influence of the secondary electron emission coefficient, γ, and the relative permittivity, ɛ
r, of the dielectric layers on the characteristics of dielectric-barrier discharges (DBDs) is studied by means of numerical modelling and calculated results are compared with experimental data. The analysis has been performed for a geometrically symmetric, plane-parallel DBD in argon with copper electrodes covered by quartz dielectrics. A time-dependent, spatially one-dimensional fluid model involving the drift-diffusion approximation is applied for the numerical analysis of the DBD operating sinusoidally at a frequency of 24 kHz with applied voltages between 1.8 and 3.4 kV and pressures from 100 to 650 mbar. Main features of the model as well as the experimental setup and procedures are given. The modelling studies show especially the sensitivity of the results on the specific choice of γ and ɛ
r regarding the occurrence and intensity of discharge peaks, the appearance of one or more smaller peaks after the main peak, as well the establishment of a single periodic, multiperiodic or even chaotic temporal evolution of the DBD. In particular, generally good agreement between measured and calculated discharge current signals and the power dissipated in the discharge is found for γ = 0.02 and ɛ
r = 4.2.
Enhancement of the lower critical field in FeSe-coated Nb structures for superconducting radio-frequency applications
Authors: Lin Zefeng , Qin Mingyang , Li Dong , Shen Peipei , Zhang Liping , Feng Zhongpei , Sha Peng , Miao Jun , Yuan Jie , Dong Xiaoli , Dong Chao , Qin Qing , Jin Kui
Published: October 2020

Bulk Nb superconducting radio-frequency (SRF) cavities are widely used in accelerators, and their accelerating gradient and general performance are limited by the superheating field (B
sh). To push the theoretical limit of the B
sh, new multilayer structures are required. We fabricated FeSe-coated Nb films using pulsed laser deposition, performed structural characterizations, and measured the transport and magnetic properties for this superconductor-superconductor bilayer structure with smooth surface. Additionally, the measured B
c1 of FeSe-coated Nb film is greatly enhanced, while the B
sh of the FeSe layer is expected to be higher than that of bulk Nb, yet the superconducting transition temperature (T
c) is less than 5 K. This work presents the first fabrication of a new coating layer: FeSe deposited on Nb, showing the possibility of using iron-based materials for multilayer structures in SRF cavities.
Computational study of solid-liquid supercritical flow of 4th-grade fluid through magnetized surface
Authors: Nazeer Mubbashar , Hussain Farooq , Shahzad Qasiar , Ali Zulfiqar , Kadry Seifedine , Chu Yu-Ming
Published: October 2020

This paper offers a comparative investigation of the multiphase flow of Newtonian and non-Newtonian dispersions passing through an inclined channel. Couette and Generalized Couette flow models are taken into account. A fourth-grade fluid is taken as non-Newtonian fluid, as well as base fluid. The stress tensor of fourth-grade fluid is used to formulate the problem. The relative motion between fluid and the upper plate is considered, while the relative motion between fluid and lower plate is mistreated. Crystal and Hafnium nano-sized particles are utilized to prepare dispersions. An external magnetic field is applied to the multiphase flows of dispersions in the channel and at the same time, the impact of gravitational force is also examined which has great mastery on flows. The governing equations for two-phase flows problem are determined by using Naiver-Stokes equations of continuity and momentum. Partial differential equations are reduced into ordinary differential equations by using appropriate transformations. The perturbation method is used to find out analytical solutions to these ordinary differential equations. Exact and approximation solutions are obtained by using MATHEMATICA Software. The impacts of salient parameters on each type of flow for velocity profile are discussed graphically. Furthermore, the comparison of velocity profiles of multiphase flows of dispersions is also presented in tabular forms. The variation in the magnitude of the fourth-grade non-Newtonian dimensionless parameter has great importance in non-Newtonian dispersions. The outcomes dispose of that the two-phase flows of Newtonian fluids suspended with crystal and hafnium particles are better one than the bi-phase flows of fourth-grade dispersions. Moreover, the Newtonian fluids suspended with hafnium particles are more consequential than the Newtonian fluids suspended with crystal particles. Similarly, the same behavior is observed in fourth-grade non-Newtonian dispersions. Then it is concluded that hafnium particles are a better option than crystal particles. These amalgams are very useful in every field of life, especially medicine as nanofluid drug delivery. In addition to this, no comparative analysis between Newtonian and fourth-grade non-Newtonian bi-phase flows has so far been reported in the existing literature.
Steady and optimal entropy squeezing for three types of moving three-level atoms coupled with a single-mode coherent field*
Authors: Huang Wen-Jin , Fang Mao-Fa
Published: October 2020

The entropy squeezing properties of different types of moving three-level atoms coupled with a single-mode coherent field are studied. The influences of the moving velocity and initial states of the three-level atom on the entropy squeezing are discussed. The results show that, the entropy squeezing properties of the three-level atom depend on its initial state, moving velocity, and the type. A stationary three-level atom can not obtain a steady entropy squeezing whatever initial conditions are chosen, while a moving three-level atom can achieve a steady and optimal entropy squeezing through choosing higher velocity and appropriate initial state. Our result provides a simple method for preparing squeezing resources with ultra-low quantum noise of the three-level atomic system without additional any complex techniques.
Double-dot interferometer for quantum measurement of Majorana qubits and stabilizers*
Authors: Zhou Kai , Zhang Cheng , Qin Lupei , Li Xin-Qi
Published: October 2020

Motivated by the need of quantum measurement of Majorana qubits and surface-code stabilizers, we analyze the performance of a double-dot interferometer under the influence of environment noise. The double-dot setup design allows accounting for the full multiple tunneling process between the dots through the Majorana island, within a master equation approach. In the co-tunneling regime, which results in a Majorana-mediated effective coupling between the dots, the master equation approach allows us to obtain analytic solutions for the measurement currents. The measurement quality, characterized by figures of merit such as the visibility of measurement signals, is carried out in regard to the unusual decoherence effect rather than ‘which-path’ dephasing. The results obtained in this work are expected to be useful for future experiments of Majorana qubit and stabilizer measurements.
The entanglement properties of holographic QCD model with a critical end point *
Authors: Li Zhibin , Xu Kun , Huang Mei
Published: October 2020

We investigated different entanglement properties of a holographic QCD (hQCD) model with a critical end point at the finite baryon density. Firstly, we considered the holographic entanglement entropy (HEE) of this hQCD model in a spherical shaped region and a strip shaped region. It was determined that the HEE of this hQCD model in both regions can reflect QCD phase transition. Moreover, although the area formulas and minimal area equations of the two regions were quite different, the HEE exhibited a similar behavior on the QCD phase diagram. Therefore, we assert that the behavior of the HEE on the QCD phase diagram is independent of the shape of the subregions. However, the HEE is not an ideal parameter for the characterization of the entanglement between different subregions of a thermal system. As such, we investigated the mutual information (MI), conditional mutual information (CMI), and the entanglement of purification (Ep) in different strip shaped regions. We determined that the three entanglement quantities exhibited some universal behavior; their values did not change significantly in the hadronic matter phase but increased rapidly with the increase in T and

in the QGP phase. Near the phase boundary, these three entanglement quantities changed smoothly in the crossover region and continuously but not smoothly at CEP; they exhibited discontinuous behavior in the first phase transition region. These properties can be used to distinguish between the different phases of strongly coupled matter.
Nearest-neighbor functions for disordered stealthy hyperuniform many-particle systems
Authors: Middlemas Timothy M , Torquato Salvatore
Published: October 2020

Disordered stealthy many-particle systems in d-dimensional Euclidean space

R

d

are exotic amorphous states of matter that suppress any single scattering events for a finite range of wavenumbers around the origin in reciprocal space. They are currently the subject of intense fundamental and practical interest. We derive analytical formulas for the nearest-neighbor functions of disordered stealthy many-particle systems. First, we analyze asymptotic small-r approximations and expansions of the nearest-neighbor functions based on the pseudo-hard-sphere ansatz. We then consider the problem of determining how many of the standard n-point correlation functions are needed to determine the nearest neighbor functions, and find that a finite number suffice. Via theoretical and computational methods, we are able to compare the large-r behavior of these functions for disordered stealthy systems to those belonging to crystalline lattices. Such ordered and disordered stealthy systems have bounded hole sizes, and thus compact support for their nearest-neighbor functions. However, we find that the approach to the critical-hole size can be quantitatively different, emphasizing the importance of hole statistics in distinguishing ordered and disordered stealthy configurations. We argue that the probability of finding a hole close to the critical-hole size should decrease as a power law with an exponent only dependent on the space dimension d for ordered systems, but that this probability decays asymptotically faster for disordered systems, with either an increase in the exponent of the power law or a crossover into a decay faster than any power law. This implies that holes close to the critical-hole size are rarer in disordered systems. The rarity of observing large holes in disordered systems creates substantial numerical difficulties in sampling the nearest neighbor distributions near the critical-hole size. This motivates both the need for new computational methods for efficient sampling and the development of novel theoretical methods for ascertaining the behavior of holes close to the critical-hole size. We also devise a simple analytical formula that accurately describes these systems in the underconstrained regime for all r. These results provide a theoretical foundation for the analytical description of the nearest-neighbor functions of stealthy systems in the disordered, underconstrained regime, and can serve as a basis for analytical theories of material and transport properties of these systems.
Understanding the role of socioeconomic and governance conditions in country-level marine aquaculture production
Authors: Ruff Elizabeth O , Gentry Rebecca R , Lester Sarah E
Published: October 2020

Marine aquaculture (i.e. seafood farming in the ocean) has the potential to substantially support growing demand for animal protein. Despite vast amounts of suitable ocean space across the world, marine aquaculture development has been slow and geographically heterogeneous, indicating that factors other than suitable farming conditions are influencing industry growth. Using multivariate techniques, this study explores to what extent certain socioeconomic, governance, and biophysical factors can explain country-level patterns of mariculture production. We find that socioeconomic conditions are a significant contributor to whether a country produces mariculture and the magnitude of its production; our models explain up to 33% more of the variation in mariculture production compared to models including only biophysical parameters. These results are relatively consistent across types of mariculture production (i.e. finfish, crustaceans, molluscs, and algae). Our findings suggest that improving seafood farming infrastructure, creating local demand for seafood, and facilitating knowledge transfer from land-based and freshwater aquaculture could help countries develop stronger mariculture industries.
Flood-induced population displacements in the world
Authors: Kakinuma Kaoru , Puma Michael J , Hirabayashi Yukiko , Tanoue Masahiro , Baptista Emerson A , Kanae Shinjiro
Published: October 2020

Strengthening the resilience of societies to extreme weather events is an urgent and critical priority around the world. Extreme weather often causes population displacement that compromises human security. Environment-induced displacement is multifaceted because climate extremes, population, and socio-economic conditions, among other factors, converge to influence individuals’ decisions to move. When large-scale, catastrophic floods occur, people tend to move both suddenly and rapidly for survival. Quantifying the patterns and mechanisms of such displacement at global scale is essential to support areas at high risk for climate-induced displacement. Here we present the global distribution of vulnerability to floods by mapping potential flood exposure and observed flood-induced displacement. We found that countries in Africa might be highly vulnerable to floods because they have high flood-induced displacement even at low- to mid-level flood exposure. Our results show that income levels (Gross National Income) substantial impact flood-induced displacement. Moreover, the relationship between income levels and displacement is nonlinear, and this nonlinearity indicates large gaps in flood-induced displacement between high- and low-income countries. We suggest that low-income countries, particularly in Africa, face a high likelihood of flood-induced displacement and need to develop adaptation measures to mitigate the potential for displacement and the associated risks.
Fabrication of Gd2O3 nanoparticles in hexane-water system using Myristica fragrans Houtt leaves extract and their photodegradation activity of malachite green
Authors: Eprasatya A , Yulizar Y , Yunarti R T , Apriandanu D O B
Published: October 2020

This study aims to fabricate the Gd2O3 nanoparticles (NPs) using Myristica fragrans Houtt leaves extract (MFE) in hexane-water phases system by high-speed stirring method. We performed a phytochemical test to qualitatively confirm that MFE contained the secondary metabolite of alkaloid, steroid and saponin as a weak base source (OH−), a stabilizing agent, and a capping agent in the Gd2O3 NPs fabrication, respectively. According to SEM image, the morphology of Gd2O3 NPs was spherical shape in agglomeration. UV-Vis DRS result shows that Gd2O3 NPs has a large bandgap which was found to be 5.1 eV. XRD characterization shows that the diffraction pattern of the formed nanoparticle was well-matched with the data source of Gd2O3. The particle size of Gd2O3 NPs was approximately 40 nm confirmed by PSA. Photocatalytic activity of Gd2O3 NPs was tested for dye degradation. In this study, malachite green was utilized as a modelling of dye. The photodegradation percentage of malachite green using Gd2O3 NPs catalyst was 75.15 % for 120 min under UV light irradiation.
The performance of sodium ion battery with NaFePO4 cathode prepared from local iron sand
Authors: Rahmawati F , Faiz Z , Romadhona D A N , Saraswati T E , Lestari W W
Published: October 2020

The performance of Sodium-Ion Battery, SIB, with NaFePO4 cathode prepared from local iron sand was investigated. The NaFePO4 was prepared through electrochemical sodiation to FePO4 layer on aluminium substrate. NaFePO4 prepared from local iron sand (from NTB, Indonesia) is named as NFP_A. The result is compared to the performance of SIB with NaFePO4 cathode prepared from a commercial FePO4, which is named as NFP_B. The SIB was fabricated in a split cell test type and a pouch type. Battery performance was measured by Cyclic Voltammetry (CV) analysis, Galvanostatic Charge-Discharge (GCD) testing, and Electrochemical Impedance Spectroscopy (EIS) measurements. CV analysis found that sodium intercalation and de-intercalation curve in NFP_A is similar to the CV curve of NFP_B. The reduction peak presents at -2.98 V and -2.99 V for NFP_A and NFP_B, respectively. Those peaks represent Na+ intercalation into FePO4 layer. The oxidation peaks, that represent deintercalation from NaFePO4 appears at 3.31 and 3.96 V. Split cell SIB with NFP_A as cathode provides 100 cycles under 1 C and 3 C current drawn. Meanwhile, the pouch type only provides 50 cycles before the capacity loss under 1 C current drawn. Each type has 100 % Coulombic efficiency indicates that all of the charged-ion can be completely discharged.
Synthesis and characterization of monodisperse core-shell Fe3O4@Au nanostructures
Authors: Yuliani T , Khalil M , Hong J W , Ivandini T A
Published: October 2020

This work reports a synthesis of monodisperse core-shell Fe3O4@Au nanostructures. Fe3O4(~4.9 nm) and core-shell Fe3O4@Au (5.0–5.6 nm) nanostructures were successfully synthesized via thermal decomposition method of iron compounds in the presence of oxygen-containing ligands. XRD analysis revealed the pure face-centered cubic (FCC) structure of Fe3O4with 2 θ peaks at 31 °, 38 °, 44 ° and 64 °, 77 ° and 81 ° attributed to Fe-Au, which can be indexed to lattice planes of gold in a cubic phase. In addition, UV-Vis spectra showed a significant difference absorbance peak between Fe3O4NP and Fe3O4@AuNP.
Molecular investigation of modified β-cyclodextrin and cholesterol inclusion complexes through molecular docking simulations
Authors: Nasution M A F , Riyanto H G , Saepudin E , Ivandini T A
Published: October 2020

Hypertension, a medical condition which commonly associated with cardiovascular diseases, the most lethal non-communicable diseases in the world, is indicated by the high blood cholesterol level. Thus, maintaining the blood cholesterol level is essential especially for hypertension-diagnosed patients. In this study, the molecular docking simulations were successfully performed between cholesterol and methylene blue (MB) with the modified β-cyclodextrin (BCD) compounds as the guest and host molecules, respectively, to investigate their molecular interaction when forming the inclusion complexes. The docking results showed that the modification on the -OH hydroxyl group at position 6 of BCD improves the binding affinity of the cholesterol when forming the inclusion complex, where the -OCH3modification has the highest binding affinity toward cholesterol, with ΔGbindingvalue of -5.9 kcal/mol, followed by -OCH2CHO, -OCH2COOH and -OCOCOH(COOH)2, with ΔGbindingvalue of -5.8 kcal/mol. Moreover, the hydrophobic and van der Waals interactions were observed as the most dominant interactions when both BCD-modified compounds/cholesterol and BCD-modified compounds/MB inclusion complexes were formed. Thus, the electrochemical technique can be employed toward the cholesterol and these BCD-modified compounds to validate the docking results and determine its sensitivity as cholesterol sensor.
Synthesis and characterization of soft and hard templated mesoporous carbon using phloroglucinol as carbon precursor
Authors: Amelia I , Krisnandi Y K , Abdullah I
Published: October 2020

In this study, both soft and hard templated mesoporous carbon (ST MC and HT MC) were synthesized using phloroglucinol as carbon precursor. The templates used in soft and hard templated MC synthesis were Pluronic 127 (F-127) and SiO2, respectively. The resulting mesoporous carbon were then impregnated with Ni and characterized using FTIR, SEM-EDS, BET, and XRD to investigate the functional groups, surface morphology, chemical composition, pore character, and crystallinity of the materials. The resulting Ni/MC was then utilized as a catalyst in transformation of CO2 via carboxylation of phenylacetylene. The catalytic reactions were conducted with a variety of contact time (2, 4, 6 and 8 h) to obtain a reaction condition with the highest yield of phenyl propiolic acid. The resulting final product was tested using HPLC instrument. The phenyl propiolic acid showed best peaks at reaction time of 6 h for ST Ni MC catalyst with the area of 301 mAU and yield of 1.4 %. Meanwhile, HT Ni/MC catalyst showed the best performance in phenyl propiolic acid formation at the reaction time of 8 h with the area of 453 mAU and yield of 2.2 %.
Manufacturing of Mg-Al5TiB composite and addition of nano-sized Al2O3 through stir casting method with T6 heat treatment temperature variation
Authors: Yusuf S , Syahrial A Z
Published: October 2020

In order to find aluminium replacement for vehicle structure and also application of automotive components, the research on Mg-Al-Ti-B composite was performed in this work. The composite of magnesium is highly compatible to be applied in vehicle body structure because of its low weight and density. Therefore, the lightweight of vehicle body structure, great mechanical properties, and high efficiency can be obtained. Mg-Al-Ti-B serves as the matrix, and 0.20 vf% of nano-sized Al2O3 is applied as the reinforcement. The composite of Mg-Al-Ti-B was produced through a stir casting process. Hereafter, T6 heat treatment was employed with variation of aging temperature, such as 170 °C, 200 °C, 230 °C and 260 °C for 6 h, subsequent the previous 1 h, 420 °C for the treatment of solution. The T6 heat treatment impact on microstructure indicates a different morphology of primary Mg17Al12 in which spheroidization occurs, the precipitation of Al3Ti and TiB2 are also observed from the aging process. In this work, OM, EDS, XRD, OES, density and porosity measurements, as well as destructive tests were performed for the characterization. The T6 heat treated sample’s mechanical properties were rectified than the non-heat treated ones. The highest ultimate tensile strength was obtained with 65.31 MPa at 170 °C aging temperature. The optimum value of hardness, impact value and wear rate are observed at 200 °C aging temperature, the values are 92.4 HRH, 0.07 J/mm2 and 0.00254 mm3/m, respectively.
Development study of iron-based metal organic frameworks (Fe-based MOFs) as a binding agent in diffusive gradient in thin film method (DGT) for phosphate adsorption
Authors: Sintya V , Saefumillah A , Zulys A
Published: October 2020

In this study, Fe-based Metal Organic Frameworks (MOFs) will be developed as a binding agent in Diffusive Gradient in Thin Film (DGT) for phosphate adsorption, where it will be evaluated for the effect of pH, adsorbent concentration and mixing time in phosphate loading capacity of Fe-based MOFs in DGT because these parameters can influence the capacity of phosphate adsorption. Fe-based MOFs were synthesized using ferrichloride as a binding agent and terephthalic acid as a linker in solvothermal conditions. Fe-based MOFs will be characterized by X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX), Brunauer-Emmelt Tellers (BET). The XRD peaks correspond to MIL-101 for 2 θ around 9 ° and 17 °. FTIR analysis indicated the broadening peak at 1595 cm−1 for C=O and 1395 cm−1 for C-C vibrational. The SEM analysis showed the morphology was rhombus. The BET analysis showed the surface area of Fe-based MOFs was 61.33 m2g−1. Fe-based MOFs have been successfully synthesized by the solvothermal method and then will be applied as binding agent in DGT. Furthermore, Fe-based MOFs in DGT will be used for phosphate adsorption and measured using Spectrophotometer UV-Vis.
Functionalization of titanium dioxide through dye-sensitizing method utilizing red amaranth extract for phenol photodegradation
Authors: Kurniawan Y S , Anggraeni K , Indrawati R , Yuliati L
Published: October 2020

In this work, red amaranth (RA) extract was utilized as the source of the natural pigments for dye-sensitizing of the TiO2. The natural pigments were isolated from the RA leaves through a maceration technique to obtain the RA extract as a red powder. Since photocatalytic efficiency of titanium dioxide (TiO2) under visible light is negligible, further modification such as by addition of dye-sensitizer is required. The TiO2 was sensitized using the natural pigments contained in the RA extract using (3-aminopropyl)trimethoxysilane (APTMS) as the linker agent through an impregnation method to give the dye-sensitized TiO2 composite (RA-APTMS/TiO2). After dye-sensitizing, new absorption peaks at 1632–1030 cm−1 were detected in the Fourier transform infrared (FTIR) spectra, which were corresponded to the functional groups of chlorophyll originated from the RA extract. Furthermore, the appearance of a new absorption peak at 665 nm in the diffuse reflectance ultraviolet-visible (DR UV-vis) spectra also supported the successful sensitization of the TiO2 by the RA extract. Photocatalytic tests showed that while the unmodified TiO2 could not degrade phenol under visible light, the RA-APTMS/TiO2 composites exhibited photodegradation ability in 9, 13, 22 and 7 % when using 5, 10, 20 and 30 % mass ratio of the RA extract, respectively.
Effect of zirconium substitution on structural and optical properties of lanthanum orthoferrite
Authors: Purnamasari I , Triyono D
Published: October 2020

Lanthanum Orthoferrite (LaFeO3) is one of the perovskite oxide ABO3 materials. In this study, LaFe1-x
Zr
x
O3 ( x = 0.01, 0.03 and 0.05) were synthesized by sol-gel method. Synthesized LaFeO3 with substituted Zr on Fe-site was characterized for crystal structures and optical properties. The X-ray diffraction (XRD) analysis confirms that the LaFe1-x
Zr
x
O3 material has an orthorhombic structure with Pnma space group. The local structure of this sample was studied using Raman spectroscopy. Raman analysis shows, there are Zr4+ substituted effect on the tilt and stretching phonon modes of LaFeO3. Fourier Transform Infrared (FTIR) characterization test confirmed the effect of substitution on structural properties in terms of the upward shift of tilt, bending, and symmetric stretching of Fe-O-Fe bonds in FeO6. Optical bandgap has been determined using Kubelka-Munk function with the Tauc connection by the Uv-Vis Spectrophotometer which shows that the energy bands decrease (2.14–2.10 eV) with increased Zr-content.
Modification of fly ash using acids and alkali by hydrothermal method and its application as adsorbents material for phosphate adsorption in aquatic system
Authors: Wulandari W R , Saefumillah A , Yunarti R T
Published: October 2020

In this research, fly ash was modified with acids, such as HCl, H2SO4 and mixture of both and alkali with hydrothermal method. XRF analysis showed a decrease of CaO and Fe2O3 contents in HMFA, SMFA and HSMFA while AMFAWH has higher CaO content and produced the new zeolite phase (hydroxy-sodalite) in 2 θ = 24.232 ° from XRD test. FTIR analysis showed that the fly ash gave absorption band of O-H group, H-O-H bend group, and Si-O stretching group. SEM images showed that acid-modified fly ash indicated a deposition of gehlenite crystals while AMFAWH showed flat rectangular shaped small particle known as hydroxy-sodalite. The BET method analysis indicated that all adsorbents were classified as mesopores. The experimental data showed that adsorption efficiency and capacity of fly ash was improved significantly after modification. The unmodified fly ash (UFA) has the highest phosphate adsorption efficiency and capacity in 0.16 g was 60.07 % and 0.485 mg P-PO4/g while modified fly ash (HSMFA) was 85.62 % and 0.705 mg P-PO4/g. The optimum contact time were obtained at 240 min for UFA, HMFA, SMFA and 480 min for HSMFA and AMFAWH. The optimum of pH were obtained at pH 5 and pH 7 for the others. The fifth adsorbents follow the Freundlich isotherm and pseudo-second-order kinetic model in phosphate adsorption.