bluuebunny/crossref_metadata_2025 huggingface dataset:
Vibronic coupling density analysis and quantum dynamics simulation for singlet fission in pentacene and its halogenated derivatives
Authors: Nagami Takanori , Tonami Takayoshi , Okada Kenji , Yoshida Wataru , Miyamoto Hajime , Nakano Masayoshi
Published: October 2020

We theoretically investigate microscopic origins of vibronic coupling (VC) contributing to singlet fission (SF) dynamics in pentacene and its halogenated derivatives. The features of VCs related to diabatic exciton states and interstate electronic couplings (Holstein and Peierls couplings, respectively) are interpreted by the VC density (VCD) analysis, which allows one to clarify the relationship between the chemical structure and VC as spatial contribution. It is found for the pentacene dimer face-to-edge configuration in a herringbone crystal that characteristic intermolecular vibrations with low frequencies exhibit strong Holstein couplings for the intermediate charge-transfer (CT) exciton states as well as Peierls couplings. From VCD analysis, the comprising density of the intermolecular CT and that of the intermolecular vibration are found to be constructively mixed in the intermolecular space, leading to the enhancement of VC. Moreover, in order to assess the chemical modification manner for controlling VC, we design several halogenated pentacene derivatives with slip-stack configurations. Our strategy to enhance VCD by halogenation is found to be rational, whereas the peaks of VC spectra for the CT states in the slip-stack packings are observed in high frequency regions. We compare their SF dynamics based on the quantum master equation explicitly including the exciton state-dependent VCs. From the analysis on relative relaxation factors between the adiabatic exciton states, their difference in the SF rate is highlighted by exciton configurations in addition to VCs. The present study is expected to be a first step toward efficient SF based on the design of VC in terms of both the chemical structure and intermolecular packing.
Transitions between systems of satellite vortices in a rotating fluid
Authors: Di Labbio Giuseppe , Ait Abderrahmane Hamid , Fayed Mohamed , Ng Hoi Dick
Published: October 2020

We investigate experimentally the transitions between systems of two and three satellite vortices found within a shallow layer of water above a rotating disk at the bottom of an open stationary cylindrical tank. We found that these systems of two and three satellite vortices are associated with two fundamental multipolar modes, namely, the quadrupole and hexapole, respectively. The forward and backward transitions between the two systems of satellite vortices, which occur at critical disk speeds, involve growth and decay of the fundamental modes as well as the excitation of their common harmonic (the dodecapole) and symmetric radial oscillations.
Reflections on an academic job search
Authors: Magaña-Loaiza Omar S.
Published: October 2020

The road from reading a job posting to signing a contract is long and involved. Advice from a recently hired professor may smooth the path.
Where does outer space begin?
Authors: McDowell Jonathan
Published: October 2020

As suborbital space tourism gears up, the decades-old debate about the boundary of Earth’s atmosphere continues.
Commentary: on the under-valuing of Australia’s expertise in drylands research and practice globally
Authors: Metternicht Graciela , Smith Mark Stafford
Published: October 2020

Global drylands are a significant driver of earth system processes that affect the world’s common resources such as the climate. Their peoples are also among the first to be widely affected by global changes such as land degradation and climate change. Yet drylands are a source of many social and technical innovations, globally, as well as in Australia. As a major developed dryland nation, Australia has previously played a major role in extending these innovations to the rest of the world. The nation has reaped reputational and commercial benefits through major research and practice contributions to dryland agriculture, water management and governance, remote area services, indigenous partnerships, dryland monitoring systems, and ‘desert knowledge’ innovation. Australian researchers continue to contribute to various relevant international processes, yet recognition and support for this within Australia has dropped off markedly in recent years. We analyse the Australian government’s investment in research and in overseas aid for drylands over the last two decades, and explore trends in government’s active involvement in major international processes related to land. These trends are short-sighted, overlooking potential economic benefits for Australian enterprises, and undermining Australia’s stance and scientific leadership in dryland systems globally. In this commentary, we argue that it is time for the trends to be reversed, as this is an area of comparative advantage for Australian diplomacy with significant returns on investment for Australia, both direct and indirect, especially when most emerging economies contain substantial drylands. We identify four major pathways to obtaining benefits from science diplomacy, and four interrelated actions within Australia to enable these – to place a higher emphasis on science diplomacy, to re-forge a bipartisan recognition of Australian drylands expertise, to establish a dedicated Dryland Information Hub, and to create a network of relevant science and technology advisors.
Analysis of barotactic and chemotactic guidance cues on directional decision-making of
Dictyostelium discoideum
cells in confined environments
Authors: Belotti Yuri , McGloin David , Weijer Cornelis J.
Published: October 2020

Significance

Cells confined in complex environments use a combination of chemical and mechanical cues for robust pathfinding and effective migration. Analysis of directional “decision-making” of
Dictyostelium discoideum
cells migrating within microchannels harboring asymmetric bifurcations shows that unlike neutrophils and immature dendritic cells
Dictyostelium
cells use chemical rather than barotactic guidance cues. Cells in steeper adenosine 3′,5′-cyclic monophosphate gradients migrating at higher speeds split their leading edges more readily when confronted with a bifurcation in the channel. The point at which one of the competing pseudopods starts to retract appears to be dependent on a relative force imbalance between two competing pseudopods, showing that cellular mechanics plays a major role in leading-edge dynamics, including front splitting, polarization, and retraction in
D. discoideum
.
An expert advantage in detecting unfamiliar visual signals in noise
Authors: Hussain Zahra
Published: October 2020

Significance

Radiologists have years of experience in inspecting medical images for anomalies and thus are visual experts with the particular object class of medical images. Do the perceptual skills acquired in medical imaging benefit perception outside the trained domain? Here, radiologists and novice controls were compared on the ability to perform a visual detection task that was unfamiliar to all subjects. Subjects detected patterns in noise that were unlike medical images to which radiologists are routinely exposed. Radiologists were superior to the control groups in all stimulus conditions and maintained their advantage after both groups improved on the task. These results suggest that the perceptual skills developed in diagnostic radiology generalize to certain unfamiliar visual judgments.
Functional rewiring across spinal injuries via biomimetic nanofiber scaffolds
Authors: Usmani Sadaf , Franceschi Biagioni Audrey , Medelin Manuela , Scaini Denis , Casani Raffaele , Aurand Emily R. , Padro Daniel , Egimendia Ander , Ramos Cabrer Pedro , Scarselli Manuela , De Crescenzi Maurizio , Prato Maurizio , Ballerini Laura
Published: October 2020

Significance

Nanotechnology and neurobiology combined efforts might succeed in the design of hybrid microsystems that, once functionally integrated into the nervous tissue, might help in healing the injured spinal cord. A substantial challenge in this area is the development of structural scaffolds favoring spinal cord reconstruction. The future success of such smart devices resides also in the use of nanomaterials exploiting spinal microenvironment physical properties, such as mechanical and electrical ones, and their potential in promoting axonal regeneration. We synthesized an artificial scaffold based on nanomaterials with the necessary characteristics to guide axonal rewiring. The translational potential of introducing physics rules to neural tissue repair strategies was tested by implanting such a scaffold in spinal cord injury animal models.
Myristate can be used as a carbon and energy source for the asymbiotic growth of arbuscular mycorrhizal fungi
Authors: Sugiura Yuta , Akiyama Rei , Tanaka Sachiko , Yano Koji , Kameoka Hiromu , Marui Shiori , Saito Masanori , Kawaguchi Masayoshi , Akiyama Kohki , Saito Katsuharu
Published: October 2020

Significance

The origins of arbuscular mycorrhizal (AM) fungi, which form symbiotic associations with land plants, date back >460 Mya. During evolution, these fungi acquired an obligate symbiotic lifestyle, and thus depend on their host for essential nutrients. In particular, fatty acids are regarded as crucial nutrients for the survival of AM fungi, owing to the absence of genes involved in de novo fatty acid biosynthesis in the AM fungal genomes that have been sequenced so far. Here we show that myristate initiates AM fungal growth under asymbiotic conditions. These findings will advance the pure culture of AM fungi.
Visualizing Rev1 catalyze protein-template DNA synthesis
Authors: Weaver Tyler M. , Cortez Luis M. , Khoang Thu H. , Washington M. Todd , Agarwal Pratul K. , Freudenthal Bret D.
Published: October 2020

Significance

Translesion synthesis (TLS) DNA polymerases bypass DNA damage that is unable to be accommodated by replicative DNA polymerase active sites. The TLS polymerase Rev1 bypasses a variety of DNA damage, including exocyclic guanine adducts and abasic sites using a unique protein-template mechanism. Using time-lapse X-ray crystallography, computational analysis, and enzyme kinetics, we provide insight into the protein-template mechanism used by Rev1. Our structural snapshots identify that movement of the primer DNA strand facilitates precatalytic organization of the Rev1 active site and phosphodiester bond formation. Additionally, we determine postcatalytic events, including pyrophosphate hydrolysis in the active site and an inability to reincorporate the templating guanine into the DNA helix, which ultimately prevents mutagenic processivity by Rev1.
From the oral-literate debate to the translanguaging paradigm – and back again
Authors: Münch Christian , Noack Christina
Published: October 2020

For several years now, the current debates on multilingualism and multi­literacy have revolved around the concept of translanguaging. In our paper we aim to contribute to the debate by presenting two theoretical approaches that have fueled the debate in the German-speaking academic context over the last thirty years and bringing them to the attention of an international readership. In discussing the analysis of written data of multilingual speakers from an acquisition perspective, we wish to demonstrate the fascinating aspects these works can contribute.
EURAMET key comparison 1031 (EURAMET.M.D-K1.1)—solid density comparison
Authors: Bettin Horst , Borys Michael , Firlus Martin , Buchner Christian , Zelenka Zoltan , Medina Nieves , Parlić-Risović Tijana , Bezjak Mladen , Mitsas Chris , Lefkopoulos Alexandros , Lenard Elżbieta , Popa George Florian , Malengo Andrea , Madec Tanguy , Beaudoux Florian , Fuchs Peter , Marti Kilian , Wüthrich Christian , Kajastie Heikki , Eltawil Alaaeldin A , Fujii Ken-ichi , Kuramoto Naoki , Waseda Atsushi , Perkin Michael , Davidson Stuart , Açadağ Ümit Y , Domostroev Aleksey
Published: October 2020

The results are presented of the key comparison EURAMET 1031 (EURAMET.M.D-K1.1) that covered the measurements of density and volume of silicon spheres of three different masses at 20 °C and 101325 Pa. The volume and density determinations of 15 national metrology institutes (NMIs) were checked and linked to the CCM.D-K1 key comparison. The measurements were carried out near 20 °C and at atmospheric pressure by the hydrostatic method in the time interval from 16 May 2008 to 18 Jan 2011.

The comparison was performed in two petals with three spheres in each petal. The travelling standards of petal 1 have a mass of 1001 g, 200 g and 35 g (Petal 2: 984 g, 239 g, 35 g). Whereas the reference values of the 1 kg travelling standards could be determined by the link to the CCM.D-K1 comparison, the density reference values for the smaller spheres were determined by density comparison to the 1 kg spheres using the pressure-of-flotation method.

One result was wrong due to a mistake in the mass determination. Additionally, four of the 57 volume (or density) values were discrepant with En values larger than 1.1, 1.2, 1.3 and 1.6.

Five NMIs achieved density uncertainties of about 1 ppm (1 × 10−6 in relative terms) or less for the 1 kg spheres. This satisfies the needs of all customers who wish to calibrate solid density standards for other laboratories.

Volume determinations of mass standards, air density artefacts or sorption artefacts should reach an uncertainty of about 1 mm3 in order to reduce the effect on the mass uncertainty to about 1 μg. At least for silicon spheres this is reached by eight NMIs. Due to the higher density of stainless steel this may be different for weights and will be checked within the CCM.D-K3 comparison.

The results of the comparison can be used to submit new or improved entries in the calibration measurement capabilities table in the BIPM key comparison database.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Rigidity results of free boundary maximal hypersurfaces in the region bounded by a de Sitter space
Authors: Park Sangwoo , Pyo Juncheol
Published: October 2020

This paper provides the rigidity results of free boundary maximal hypersurfaces in a region bounded by a de Sitter space in the Lorentz–Minkowski space. First, it is proved that any smooth, compact free boundary maximal hypersurface in a de Sitter ball is the spacelike coordinate planar disk passing through the center of the de Sitter space. Second, a smooth, noncompact, complete free boundary maximal hypersurface in the exterior of a de Sitter ball is considered. For maximal hypersurfaces with one planar end in the exterior of a de Sitter ball, every complete noncompact free boundary maximal hypersurface is shown to be a part of the spacelike coordinate hyperplane.
Oxygen reduction reaction on Pd nanocatalysts prepared by plasma-assisted synthesis on different carbon nanomaterials
Authors: Lüsi Madis , Erikson Heiki , Treshchalov Alexey , Rähn Mihkel , Merisalu Maido , Kikas Arvo , Kisand Vambola , Sammelselg Väino , Tammeveski Kaido
Published: October 2020

In this work He/H2 plasma jet treatment was used to reduce Pd ions in the aqueous solution with simultaneous deposition of created Pd nanoparticles to support materials. Graphene oxide (GO) and nitrogen-doped graphene oxide (NrGO) were both co-reduced with the Pd ions to formulate catalyst materials. Pd catalyst was also deposited on the surface of carbon black. The prepared catalyst materials were physically characterized using transmission electron microscopy, scanning electron microscopy and x-ray photoelectron spectroscopy. The plasma jet method yielded good dispersion of small Pd particles with average sizes of particles being: Pd/rGO 2.9 ± 0.6 nm, Pd/NrGO 2.3 ± 0.5 nm and Pd/Vulcan 2.8 ± 0.6 nm. The electrochemical oxygen reduction reaction (ORR) kinetics was explored using the rotating disk electrode method. Pd catalyst deposited on nitrogen-doped graphene material showed slightly improved ORR activity as compared to that on the nondoped substrate, however Vulcan carbon-supported Pd catalyst exhibited a higher specific activity for oxygen electroreduction.
Metalorganic chemical vapor deposition grown n-InGaN/n-GaN tunnel junctions for micro-light-emitting diodes with very low forward voltage
Authors: Li Panpan , Zhang Haojun , Li Hongjian , Zhang Yuewei , Yao Yifan , Palmquist Nathan , Iza Mike , Speck James S , Nakamura Shuji , DenBaars Steven P
Published: October 2020

High performance GaN-based micro-light-emitting diodes (µLEDs) with epitaxial n-InGaN/n-GaN tunnel junctions (InGaN TJs) were grown by metalorganic chemical vapor deposition (MOCVD). The InGaN TJs µLEDs show a significant reduction of forward voltage (Vf) by ∼0.6 V compared to the common TJs µLEDs. The Vf at 20 A cm−2 is very low varied from 3.15 V to 3.19 V in small InGaN TJ µLEDs with a size less than 40 × 40 µm2, and then significantly increases in large LEDs. Selective area growth (SAG) of TJs can overcome such size limitation by vertical out diffusion of hydrogen through the apertures on top of p-GaN. The InGaN TJ µLEDs overgrown by SAG show a size-independent low Vf ranged from 3.08 V to 3.25 V. The external quantum efficiency (EQE) of the packaged TJ µLEDs was improved by 6% compared to the common µLEDs with indium tin oxide (ITO) contact. This work solves the key challenges of MOCVD-grown TJs.
Comparative study on ethylene glycol based Ag-Al
2
O
3 and Al
2
O
3 nanofluids flow driven by electroosmotic and peristaltic pumping: a nano-coolant for radiators
Authors: Akram Javaria , Akbar Noreen Sher , Tripathi Dharmendra
Published: October 2020

This paper aims to provide a comparative analysis of hybrid (Ag- Al
2
O
3) nanofluid and Al
2
O
3 mono nanofluid in a convective heat transfer process driven by electroosmotic and peristaltic pumping. Ethylene glycol (EG) due to its strong anti-freezing properties is taken as a base fluid. The features of mixed convection, magnetohydrodynamics, and Joule heating are also comprised in this study. The slip boundary conditions for axial velocity and temperature are employed at the walls of the microchannel in a porous environment and conditions of zero normal mass flux are imposed for the passive control of nanoparticles. This model is composed by using the Buongiorno flow model along with the modified Maxwell-Garnett model for thermal conductivity of hybrid nanofluids and Poisson-Boltzmann distribution for electric potential generated within the fluid medium. The problem is simplified under the approximations of lubrication theory and Debye–Hückel linearization and the numerical computations have been made through Maple 17 code. The graphical results of flow variables for various involved quantities are prepared and presented with a requisite interpretation. Moreover, contour graphs are also plotted for stream function in order to discuss the trapping phenomenon. The addition of a volume fraction of 9% of aluminum dioxide in ethylene glycol tends to raise the thermal conductivity of working fluid up to 28.97% however further addition of a small number of silver nanoparticles increases its thermal conductivity up to 53.57%. Due to this increment in thermal conductance, it is found that the efficiency of Ag- Al
2
O
3 nanofluid in the heat transfer mechanism is better than the Al
2
O
3 nanofluid. It is further reported that EG based hybrid nanofluid (Ag- Al
2
O
3) as nano-coolant is more applicable for radiators and other cooling systems as compared EG based (Al
2
O
3) nanofluid.
Darboux-dressing transformation, semi-rational solutions, breathers and modulation instability for the cubic-quintic nonlinear Schrödinger system with variable coefficients in a non-Kerr medium, twin-core nonlinear optical fiber or waveguide
Authors: Yang Dan-Yu , Tian Bo , Qu Qi-Xing , Li He , Zhao Xue-Hui , Chen Su-Su , Wei Cheng-Cheng
Published: October 2020

Twin-core optical fibers are applied in the fiber optic sensing technique and optical communication. Non-Kerr media are seen in plasma physics, nonlinear quantum mechanics and nonlinear optics. Propagation of an optical beam and superradiance for an atom in the waveguide are reported. This paper investigates the cubic-quintic nonlinear Schrödinger system with variable coefficients for the ultrashort optical pulse propagation in a non-Kerr medium, twin-core nonlinear optical fiber or waveguide. For the two components of the electromagnetic fields, Darboux-dressing transformation, semi-rational solutions and breather solutions are obtained. We acquire the Akhmediev breathers (ABs) and Kuznetsov-Ma (KM) solitons. Interaction between the rogue waves and KM/bright-dark solitons is presented. When b(z) is a linear/quadratic/cosine function, the ABs, rogue waves, KM and bright-dark solitons appear parabolic, cubic and wavy, respectively, where b(z) presents the delayed nonlinear response effects. We conduct the modulation instability for the plane wave solutions for a non-Kerr medium, twin-core nonlinear optical fiber or waveguide via the linear stability analysis: If χ < 0, the solutions are modulationally stable; otherwise, modulationally unstable, where χ is the growth rate of the instability.
Preface
Authors: Zank G P
Published: October 2020

The 19th Annual International Astrophysics Conference (AIAC) was held at the beautiful La Posada de Santa Fe Hotel, Santa Fe, New Mexico, USA from March 9 to 13, 2020. This year’s meeting was exceptionally challenging, coming immediately prior to the onset and shutdown of the U.S. in response to the then rapidly developing COVID-19 outbreak. Of course, our Asian, Oceania, African, and European friends and colleagues were already either in or about to enter their own shutdowns. In addition, organizations such as NASA and various universities imposed their own travel restrictions just before the start of the meeting. Faced with the chaos and absence of any meaningful public health advice at the time, we made the difficult decision to go forward with the meeting in a truncated form and at the last minute managed to introduce conference meeting technology Zoom to aid us with those speakers who could not physically be there. I would like to thank conference organizer Adele Corona of ICNS, her assistant Kathy Tolbert, and the entire staff at the La Posada for their immense and untiring efforts in making the meeting the success that it was. Their acute ability to adapt to these last-minute changes, and their efforts to ensure as safe an environment as possible for all our attendees was crucial. Little did we know that this worldwide crisis was simply a foretaste of much, much worse to come. Therefore, and not surprisingly, we have pushed the 20th AIAC meeting well back into Fall of 2021 and we sincerely hope that the world will have recovered some degree of normalcy that will allow us to return to social activities of the past!

The theme of the 19th AIAC was “From the Sun’s Atmosphere to the Edge of the Galaxy: A Story of Connections” and had a format of 25-minute presentations punctuated by selected 40-minute invited talks that explored various themes in greater detail.

The oldest and the newest heliospheric space missions are distinguished by being the farthest and closest human-made objects ever to the Sun. Plunging into the depths of the atmosphere of the Sun, the Parker Solar Probe, launched in August 12, 2018, had completed the first three closest encounter passes to the Sun, edging closer and closer with each orbit, at the time of the meeting. The venerable Voyager 1 spacecraft, launched in 1977, entered the very local interstellar medium on 25 August 2012 and at ∼141 astronomical units from the Sun is now further from the Earth than any other human-made object. Voyager 2, following suit, likewise entered the interstellar medium on 5 November 2018. It is astonishing that, since the start of the space age in October 1957, humankind is now reaching for the stars and reaching into a star itself. Despite the immense distance separating the Voyager spacecraft from the Sun, the Sun’s influence is still felt in the immensely cold distant very local interstellar medium. This conference addressed the connected story of how the Sun and interstellar medium collectively shape their environment.
Evolution of entropy in the outer heliosphere
Authors: Adhikari L , Zank G P , Zhao L-L , Webb G M
Published: October 2020

Entropy is an important thermodynamic quantity. Based on the conservation equations of a coupled solar wind and turbulence model, and using measurements from Voyager 2, Pioneer 10 and New Horizons, we investigate the solar wind entropy throughout the heliosphere. Observations from Voyager 2, Pioneer 10, and the NH SWAP instrument show different radial profiles of the entropy as a function of heliocentric distance. We find that the entropy measured by (i) Voyager 2 increases by about 12.84% at 75 au, (ii) NH SWAP increases by about 7.8% at 46.37 au, and (iii) Pioneer 10 increases by about 6.5% at 56.82 au. Voyager 2 and NH SWAP made measurements in the upwind direction and Pioneer 10 is in the downwind direction. We compare directly the theoretical results with Voyager 2 measurements only, and find good agreement between them.
Parametric instabilities in a two ion species plasma as a driver of super Alfvénic waves
Authors: Matsukiyo S.
Published: October 2020

Linear dispersion relation of parametric instabilities of a left hand circularly polarized wave in a three species plasma consisting electrons, protons, and α particles is derived and the obtained dispersion relation is numerically solved. It is shown that the so-called super Alfvénic waves, which are thought to play important roles in preferential acceleration of heavy ions, can get excited through a parametric decay instability when the parent wave is on the proton cyclotron branch and the plasma beta is sufficiently low. A variety of other parametric instabilities are also generated.
The Interaction of Current Sheets with a Shock Wave and Particle Acceleration
Authors: Nakanotani Masaru , Zank Gary P. , Zhao Lingling
Published: October 2020

We investigate the interaction of a shock wave with multiple current sheets using a 2D hybrid simulation. We set the separation between current sheets at 25c/Wi and the thickness longer than the ion inertial length. While the current sheets are stable upstream, they become unstable to the tearing instability since the thickness becomes shorter than the ion inertial length after they interact with the shock wave. Magnetic islands produced by the instability evolve into larger islands through coalescence and the electromagnetic fields become turbulent far downstream. We also observe that the number of energetic particles increases with distance away from the shock wave and that the increase corresponds to the evolution of the current sheets.
Voyager 2 Observations Near the Heliopause
Authors: Richardson John D. , Belcher John W. , Burlaga Leonard F. , Cummings Alan C. , Decker Robert B. , Opher Merav , Stone Edward C.
Published: October 2020

This paper discusses plasma characteristics in the heliosheath region before the heliopause (HP), at the HP, and in the very local interstellar medium (VLISM). The Voyager 2 (V2) HP was a sharp boundary where the radial plasma currents went to background levels. The radial flow speeds derived from 53-85 keV (V1) and 28-43 keV (V2) ion data decreased about 2 years (8 AU) before the HP at V1 and V2. A speed decrease was not observed by the V2 plasma instrument until 160 days (1.5 AU) before the HP crossing when V2 entered the plasma boundary layer where the plasma density and 28-43 keV ion intensity increased. We determine the HP orientation based on the plasma flow and magnetic field data and show these observations are consistent with models predicting a blunt HP. Variations are observed in the currents observed in the VLISM; roll data from this region clearly show the plasma instrument observes the interstellar plasma and may be consistent with larger than expected VLISM temperatures near the HP.
Observational Evidence for the Parametric Decay in a Solar Type III Radio Burst
Authors: Thejappa G. , MacDowall R. J.
Published: October 2020

The STEREO spacecraft has provided new observational evidence for the parametric interaction, known as the electrostatic decay instability in the source region of a solar type III radio burst. The in situ high time resolution wave observations show that Langmuir waves often occur as intense one dimensional magnetic field aligned beat type of wave packets, with spectra containing peaks at fpe
, fpe
− fS
and fS
, corresponding to the beam excited Langmuir waves (L), and respectively to the daughter Langmuir (L′) and ion sound S waves generated as a result of the electrostatic decay instability (ESD) L → L′ + S. Most probably, the beat pattern is due to beating between L and oppositely directed L′, and the beat frequency corresponds to ion sound frequency. The implication of these observations for theories of solar type III radio bursts is discussed.
A kinetic perspective on azimuthal variation of magnetopause reconnection at scales below an Earth radius
Authors: Zou Ying , Walsh Brian M. , Atz Emil , Liang Haoming , Ma Qianli , Angelopoulos Vassilis
Published: October 2020

Magnetic reconnection efficiency at the Earth’s magnetopause has recently been shown to exhibit variations in reconnection jet amplitudes at azimuthal scales below an Earth radius [1]. This finding, however, is obtained based on the bulk velocity moment measurements. If there exists a significant cold magnetospheric ion population in addition to the accelerated magnetosheath population, the combination of the two would yield a low bulk velocity moment that does not necessarily correspond to a weak reconnection activity. Here we analyse ion distribution functions of the three reconnection events in [1] to examine whether the varying jet amplitudes are due to the presence of cold magnetospheric ions or variations of reconnection acceleration. Our results show that, although the cold magnetospheric ions have lowered the absolute bulk velocity, the relative variation trend of the bulk velocity is consistent with that of the acceleration gained by magnetosheath ions. The result supports the interpretation that reconnection activity can vary azimuthally on scales below an Earth radius.
Evaluation of uncertainty in determining the physical properties of concrete using Bootstrap
Authors: Afanador García N , Noriega Sanchez C J , Nolasco Serna C
Published: October 2020

This investigation analyzed the uncertainty of compression resistance in the average statistics, standard error, asymmetry, kurtosis and confidence intervals taking into account the Bootstrap method. The implementation of the Bootstrap method in determining the physical properties of the material used in the construction of buildings, is a fundamental tool to establish the physical behavior of existing buildings. The application of the Bootstrap method allowed estimating the statistics for the reported dosages with different samples; 1:2:2, allowing to estimate statistics. The results allowed to determine the probability density function of the average value of the compressive strength and with it, probabilistic resistance values can be established. This research determined statistical results of the compressive strength vital to carry out revision, vulnerability and structural reinforcement studies of existing buildings in the municipality of Ocaña, Colombia.
Removal of cadmium in wastewater by sorption on ceramics
Authors: Arenas A I , Montaño A M , González C P , Barón G C
Published: October 2020

The removal of cadmium by ceramics surfaces was investigated to evaluate sorption effectiveness of these materials in residual waters. The effects of solution pH, contact time, metal concentration and dose of sorbet material were studied in batch experiments. Ceramic material was compositionally and morphologically characterized before and after the removal of cadmium by scanning electron microscopy to establish the metal sorption Sorbent material was also tested in residual water with high cadmium content, achieving a 98% removal efficiency.
Evolution of the algebraic error in the evaluation processes mathematics and physics in engineering students
Authors: Arboledas L E , Hernández-Suárez C A , Paz-Montes L S
Published: October 2020

This research aimed to analyze the evolution of the algebraic error in the evaluation processes of mathematics and physics in engineering students, of the Universidad de Pamplona, Villa del Rosario, Colombia. Theoretically, it was based on a typology of errors. The methodology was descriptive quantitative study. The sample consisted of 77 students from engineering programs. The instruments were a Likert scale and a test of knowledge in mathematics and physics involving algebraic arithmetic operations. The results show that 9 errors were replicated in the students of the three subjects evaluated. The most frequent errors were errors when performing algebraic arithmetic operations followed by incorrect own procedures and invalid inferences and errors in the additive resolution of the potency of an unfinished binomial and procedure. In conclusion, it can be said that the same errors appear in the three subjects although it is believed that with the passing of the semesters and the training of the students they should disappear when they finish their academic program.
Influence of the physic-methodological model on the deaf youth
Authors: Rojas Suárez J P , Vergel-Ortega M , Delgado J A
Published: October 2020

The objective of this article was to evaluate the influence of the physics and urban, methodological model on the development of physical-mathematical thinking in deaf students based on research in context. Through a scale of 20 items applied to a population of 120 young deaf people between 15 and 18 years old. Factor analysis showed dimensions of pedagogical practice oriented and associate with physic thinking, variational, logical reasoning and axiomatic structure, emotional satisfaction, creative attitude, productivity, leadership competencies, motivation; internal consistency of the instrument was adequate (Cronbach alpha 0.81-0.95), a global intraclass correlation coefficient of 0.97 (95%), average differences in sum of items -1.1 (standard deviation 5.5). Physics and Urban influenced the development of physical-mathematical thinking in deaf youth in the context of “San José de Cúcuta, Colombia”.
Population ageing determines changes in heat vulnerability to future warming
Authors: Park Chang-Eui , Jeong Sujong , Harrington Luke J , Lee Myong-In , Zheng Chunmiao
Published: October 2020

Population ageing, an increase in the older age group’s portion of the total population, worsens the heat tolerance of a society. However, impacts of ageing on the social exposure to projected unprecedented hot summers (UHSs) are uncertain. We show that a shifting of the population distribution towards older ages amplifies the vulnerability of a country to the increasing frequency of UHSs as a result of warming during 2040–2070, especially in most populated regions such as China, India, and sub-Saharan countries. The warming scenarios from Representative Concentration Pathway (RCP) 8.5 are combined with population scenarios from three Shared Socio-economic Pathways (SSPs) SSP2, SSP3, and SSP5 together to estimate the exposure to UHSs. The ageing-driven increase in the exposure of elderly to UHSs ranges 51–198, 91–261, and 47–156 million in China, India, and sub-Saharan countries, respectively, between population scenarios. In China, with decreasing total population, the exposure to UHSs will be increased by rapid population ageing. In India and sub-Saharan countries, the potential of ageing to raise the exposure to UHSs will be even larger than that of warming. In contrast, in aged societies with slow ageing trend, e.g. United States and Europe, the warming mainly increases the exposure to UHSs. Our results suggest the changing age structure could exacerbate a country’s heat vulnerability despite limiting warming to a certain level in the future.
Exotic entanglement for non-Hermitian Jaynes–Cummings Hamiltonians
Authors: Frith Thomas
Published: October 2020

We provide the first solution of a time-dependent metric operator for the non-Hermitian Jaynes–Cummings Hamiltonian. We use this solution to calculate the entanglement between two identical isolated such Hamiltonians. The presence of a non-Hermitian interaction term leads to a spontaneously broken

PT

-symmetric regime which manifests itself in the exotic time-evolution of entanglement. When the symmetry is broken, oscillatory modes transition into decay. As such, there is a drastic difference in behaviour between the broken and unbroken regimes.
Implementation of Cluster Analysis and Artificial Neural Networks as an Alternative for Klassen Typology and LQ: Case of Coconut
Authors: Kusdarjito Cungki
Published: October 2020

Due to the campaign supported by manufacturers of soy-oil in the United States which stated that consuming coconut oil might cause heart disease, coconuts’ popularity started to decline. As a result, the coconut was neglected by farmers and productivity was declining. Yet, recent study showed the opposite results. Coconut was good for health. As a result, the demand for coconut products increased. Indonesia, as the world’s largest coconut producers cannot maximize these opportunities due to aging coconut which have been neglected for many years. Coconut products may improve the income of farmers and encourage sustainable agriculture as well as diversify farmers’ income. Some simple methods, such as Klassen Typology or Location Quotient can be used to classify the potential area to be developed or rejuvenated. Nevertheless, these approaches are not able to generalize and not suitable to be implemented for cases with large data. This research tried to use cluster analysis such as dendrogram, Principle Component Analysis and Artificial Neural Network for classification. The results show that the dendrogram provided good results, whilst the Principle Component Analysis and Artificial Neural Networks required more data for better results.
Growth and yield of Mung bean (Vigna radiata L.) as affected by Rhizobium sp. bacteria inoculant and frequence of watering
Authors: Ramadhani Chintya , Fuskhah Eny , Dwi Purbajanti Endang
Published: October 2020

The aim of the study was to know the influence of the Rhizobium bacteria inoculant doses as biotic fertilizer and the frequence of watering on the growth and yield of the mung bean (Vigna radiata L.). The study was conducted in Green House of Faculty Animal and Agricultural Sciences, Diponegoro University. The experimental design of this research was Completely Randomized Design (CRD) The parameters observed were height of plant, number of leaves, days of blooming, and days of pod. The result showed that the dose of the Rhizobium inoculant had a significant effect on days of blooming. The frequency of watering had significant effect on height of plant, number of leaves, days of the bloom, days of the podded and weight of pods. In conclusion, mung bean that was treatmented by Rhizobium sp. bacteria inoculant (treatments of R2, R3 and R4) and treatment of F3 had same in days of blooming and days of podded with bacteria inoculant RHIZOKA (treatment of R1).
Infertile egg powder as a potential feedstuff for starter broilers
Authors: Ratriyanto Adi , Pratitis Sabar Suprayogi Wara , Atikah Rizki
Published: October 2020

Infertile egg powder (IEP) contains a high nutrient content, particularly protein, thus it is potential to be utilized as a feedstuff. The objective of this study was to investigate the utilization of IEP as a feedstuff for starter broilers. This study used 196 one-day-old male broilers which were randomly allocated to four treatments in a completely radomized design with 7 replicates of 7 birds. The four dietary treatments included: basal diet (T0), 96% basal diet + 4% IEP (T1), 94% basal diet + 6% IEP (T2), and 92% basal diet + 8% IEP (T3). The diets were provided ad libitum. The variables were the feed intake, growth performances and feed cost. The data were subjected to analysis of variance and continued with Duncan’s Multiple Range Test. Feeding with T1, T2 and T3 did not affect the feed intake. However, T2 showed higher protein intake, while T2 and T3 showed higher energy intake than T0 (P<0.05). The IEP increased birds’ average daily gain and feed efficiency (P<0.01). The T1, T2 and T3 treatments yielded lower feed cost. It can be concluded that IEP can be utilized as feedstuff for starter broilers as indicated by improvement in growth performances.
The Effect of Solvent Ratio and Precipitation Time on Isolation of Inulin from White Sweet Potato (Ipomoea batatas L.)
Authors: Yudhistira B , Siswanti  , Luwidharto J.C.N
Published: October 2020

White sweet potato has the potential as a source of inulin and is largely abundant in Indonesia. The solvent ratio and precipitation time in ethanol solvent can increase yield produced in the inulin isolation process. This research aimed to determine the effect of different solvent ratios and precipitation times on inulin yield in the extraction-isolation process and as well to know the physical and chemical characteristics of white sweet potato inulin. The stages of the study consisted of determining the total sugar content and sugar reduction, extraction, isolation, physical and chemical characterization. This research used Factorial Completely Randomized Design (RALF) with two factors, different solvent ratio were 1:1, 1:2, and 1:3 with precipitation time for 6, 12, and 18 hours. Data were analyzed used General Linier. The analysis was followed by DMRT (a = 0,05). The results showed that the ratio of 1:2 and the precipitation time of 12 hours produced the best inulin yield of 7.72%. It had an effect on the physical characteristics of inulin that were produced, namely color, solubility, water absorption and water content. While the other characteristics in the form of ash content were not significantly different in ratio and precipitation time.
Implementation Design of Corporate Farming using Warehouse Receipt System Approach in Central Java
Authors: Budiraharjo Kustopo , Sunarno  , Solikhin  , Kunaedi Agung , Darwanto
Published: October 2020

Corporate farming is farmland merger activity jointly organized by farmers in an integrated single management. This system can be a solution for many of the problems faced by farmers today. Business efficiency, quality standardization, and effectiveness and efficiency in managing the utilization of resources are expected when the company’s agricultural system is implemented. Paddy farming in Central Java is still dominated by narrow-scale farming activities that are managed individually. This results in diverse productivity and is economically less efficient, resulting in low competitiveness. Farming activities currently carried out by farmers will be more efficient if managed by implementing a corporate farming system and supported by the Warehouse Receipt Integrated System makes microfinance institutions interested in distributing funds to capital farmers. The warehouse receipt system is supported by the concept of comparative agriculture, it is hoped that the synergy of both can increase the capital and income of farmers in Central Java.
Optimization of Farmers Working Hours through Increasing the Farm Size of Beef Cattle Production in Rural Area
Authors: Sugiarto Mochamad , Mastuti Sri , Khaerudin  , Gayatri Siwi
Published: October 2020

This study aims were to (1) identify the working hours of farmers in beef cattle farming (2) formulate the number of beef cattle that can be maintained by subsistence farmers as a side business. The study was done in rural area of Tegal Regency using survey method. 100 beef cattle farmers were selected as respondents using multistage sampling. Data was analyzed by descriptive statistics to describe the average working hours of farmers per Animal Unit (AU) and the potential time remaining by the farmers. The farmers in Tegal Regency had an average farm size of cattle of 2.40 AU. Various maintenance activities for cattle production were grazing, cleaning cattle housing, feeding and drinking, bathing the cattle. It was done by farmers for 1.75-5.10 hours/day, with an average of 3.89 hours/day. Farmers devoted the most of their time (56.04%) to take forage and grazing. Beef cattle farmers in Tegal Regency had a maximum capacity of maintaining 4.22 AU beef cattle or equivalent to 4 heads of cow.
Comparative studies of partnership between Credit Farmers (Tebu Rakyat Kredit) and Independent Farmers (Tebu Rakyat Mandiri) with Pesantren Baru sugar factory in Kediri, East Java, Indonesia
Authors: Masyhuri  , Hartono Slamet , Rahayu Lestari , Perwitasari Hani
Published: October 2020

Sugarcane plays an important role in Indonesian economics. However, recently sugarcane field has been converted into a rice field or housing. It has made a challenging to elevate sugar productivity. Located in Kediri, Pesantren Baru Sugar Factory is one of the potential places to develop sugarcane as a prime commodity in East Java, Indonesia. This study aimed to analyze the model of partnership, Credit Farmers (Tebu Rakyat Kredit/TRK) and Independent Farmers (Tebu Rakyat Mandiri/TRM) in Pesantren Baru Sugar Factory; profit of TRK and TRM; feasibility of TRK and TRM. Primary data were collected with survey method of 60 farmers and independent t-test analysis was used to compare profit and feasibility between TRK and TRM. The result showed the model of partnership in Pesantren Baru Sugar Factory were TRK and TRM. TRK was more profitable and feasible than TRM.
Investment Sensitivity of Corn Silage Production Integrated into Feed Supply Service of Dairy Cooperative
Authors: Hadiana M. H. , Suryadi D. , Daud A. R.
Published: October 2020

The study aimed to identify the sensitivity of investment in commercial corn silage production based on 20 hectares of cropland. The start-up project was prepared through a profit-sharing partnership between the South Bandung Dairy Cooperative and the owner of the land rights. The harvested whole-plant crop (WPC) was processed to produce packaged silage, further distributed to meet the needs of the member of the cooperative. Data on agriculture input and output as well as their prices were gathered through a field survey. The result of data analysis was examined within a focus group discussion attended by the project authority. The project used hybrid corn that could be planted and harvested twice in a year and yields corn silage on average 78 ton/hectare/year. It required an investment fund of IDR1.5 billion for running the project for over ten years. By using social opportunity cost of the capital of 8% a year, financially it gave a positive Net Present Value. The B/C ratio was 1.34, and the IRR was 28.5%. Three variables have to be controlled by the project management because of the sensitive effect on the project feasibility, it consists of the cost of silage distribution, selling price and WPC/hectare yielded.