Local Medium Research Articles

Slowdown and Heating of Interstellar Neutral Helium by Elastic Collisions Beyond the Heliopause.

Direct sampling of interstellar neutral (ISN) atoms close to the Sun enables studies of the very local interstellar medium (VLISM) around the heliosphere. The primary population of ISN helium atoms has, until now, been assumed to reflect the pristine VLISM conditions at the heliopause. Consequently, the atoms observed at 1 au by the Interstellar Boundary Explorer (IBEX) were used to determine the VLISM temperature and velocity relative to the Sun, without accounting for elastic collisions with other species outside the heliopause. Here, we evaluate the effect of these collisions on the primary ISN helium population. We follow trajectories of helium atoms and track their collisions with slowed plasma and interstellar hydrogen atoms ahead of the heliopause. Atoms typically collide a few times in the outer heliosheath, and only ~1.5% of the atoms are not scattered at all. We use calculated differential cross sections to randomly choose scattering angles in these collisions. We estimate that the resulting primary ISN helium atoms at the heliopause are slowed down by ~0.45 km s-1 and heated by ~1100 K compared to the pristine VLISM. The resulting velocity distribution is asymmetric and shows an extended tail in the antisunward direction. Accounting for this change in the parameters derived from IBEX observations gives the Sun's relative speed of 25.85 km s-1 and temperature of 6400 K in the pristine VLISM. Finally, this paper serves as a source of the differential cross sections for elastic collisions with helium atoms.

The Filipino Business Leader in the Time of the (COVID-19) Pandemic within the Lens of the Catholic Social Teachings

The COVID-19 pandemic is not only a global health problem—its ramifications are complex and extensive. From social routines to religious gatherings, as well as economic conditions, have all been significantly affected. The global economy has entered into a recession and local establishments, especially small and medium enterprises, have not been spared. Most of these businesses have laid-off workers and closed shops and stores. Within this chaos of business restructuring and systemic changes are complications and implications to the meaning of ethical business leadership and the value of work. This paper looks at these shifts and turns taking place in enterprises and workplaces in light of Catholic Social Thought (CST) and explores how these data and narratives from the ground could have contributed to a renewed or reshaped ethical identity of a Filipino business leader in the time of the (COVID-19) pandemic.

Study of coulomb drag with the effect of local field correction and dielectric medium

We present a numerical calculation for the drag resistivity of charge carriers interaction in coupled layer system separated by a barrier. Analytical expressions of non-linear susceptibility function and effective interlayer Coulomb interaction have been shown for non homogeneous dielectric environment at low temperature and low frequency regime. The system is studied within the model of random phase approximation (RPA) and taking into account the static local field correction (LFC). We employ Hubbard approximations (HA) and self consistent STLS approximations based LFC for obtaining the results, where LFC includes the exchange and correlation effects. Exchange and correlation effects enhanced the drag resistivity and the net screening. Another important quantity is the local form factors (LFF), which is the function of the bare inter- and intra-layer potential of the dielectric media. LFF for a multi-layer system is derived from the Poisson equation solution.

Highly polarized microstructure from the repeating FRB 20180916B

Fast radio bursts (FRBs) are bright, coherent, short-duration radio transients of as-yet unknown extragalactic origin. FRBs exhibit a variety of spectral, temporal and polarimetric properties that can unveil clues into their emission physics and propagation effects in the local medium. Here, we present the high-time-resolution (down to 1 μs) polarimetric properties of four 1.7 GHz bursts from the repeating FRB 20180916B, which were detected in voltage data during observations with the European Very Long Baseline Interferometry Network. We observe a range of emission timescales that spans three orders of magnitude, with the shortest component width reaching 3–4 μs (below which we are limited by scattering). We demonstrate that all four bursts are highly linearly polarized (≳80%), show no evidence of significant circular polarization (≲15%), and exhibit a constant polarization position angle (PPA) during and between bursts. On short timescales (≲100 μs), however, there appear to be subtle PPA variations (of a few degrees) across the burst profiles. These observational results are most naturally explained in an FRB model in which the emission is magnetospheric in origin, in contrast to models in which the emission originates at larger distances in a relativistic shock. High-time-resolution observations of the repeating fast radio burst source FRB 20180916B reveal changes to the polarization properties of the emission on timescales of a few microseconds, indicating an origin in the source magnetosphere.

Mode Engineering in Large Arrays of Coupled Plasmonic–Dielectric Nanoantennas

AbstractStrong electromagnetic field confinement and enhancement can be readily achieved in plasmonic nanoantennas, however, this is considerably more difficult to realize over large areas, which is essential for many applications. Here, dispersion engineering in plasmonic metamaterials is applied to successfully develop and demonstrate a coupled array of plasmonic–dielectric nanoantennas offering an ultrahigh density of electromagnetic hot spots (1011 cm−2) over macroscopic, centimeter scale areas. The hetero‐metamaterial is formed by a highly ordered array of vertically standing plasmonic dipolar antennas with a ZnO gap and fabricated using a scalable electrodeposition technique. It supports a complex modal structure, including guided, surface and gap modes, which offers rich opportunities, frequently beyond the local effective medium theory, with optical properties that can be easily controlled and defined at the fabrication stage. This metamaterial platform can be used in a wide variety of applications, including hot‐electron generation, nanoscale light sources, sensors, as well as nonlinear and memristive devices.

SALT observations of the supernova remnant MCSNR J0127−7332 and its associated Be X-ray binary SXP 1062 in the SMC

ABSTRACT We report the results of optical spectroscopy of the Small Magellanic Cloud supernova remnant (SNR) MCSNR J0127−7332 and the mass donor Be star, 2dFS 3831, in its associated high-mass X-ray binary SXP 1062 carried out with the Southern African Large Telescope. Using high-resolution long-slit spectra, we measured the expansion velocity of the SNR shell of ${\approx} 140 \, {\rm \, km\, s^{-1}}$, indicating that MCSNR J0127−7332 is in the radiative phase. We found that the observed line ratios in the SNR spectrum can be understood if the local interstellar medium is ionized by 2dFS 3831 and/or OB stars around the SNR. We propose that MCSNR J0127−7332 is the result of supernova explosion within a bubble produced by the stellar wind of the supernova progenitor and that the bubble was surrounded by a massive shell at the moment of supernova explosion. We estimated the age of MCSNR J0127−7332 to be ${\lesssim} 10\, 000$ yr. We found that the spectrum of 2dFS 3831 changes with orbital phase. Namely, the equivalent width of the H α emission line decreased by ≈40 per cent in ≈130 d after periastron passage of the neutron star and then almost returned to its original value in the next ≈100 d. Also, the spectrum of 2dFS 3831 obtained closest to the periastron epoch (about 3 weeks after the periastron) shows a noticeable emission line of He ii λ4686, which disappeared in the next 2 weeks. We interpret these changes as a result of the temporary perturbation and heating of the disc as the neutron star passes through it.

High Performance Gold Dimeric Nanorods for Plasmonic Molecular Sensing

A metal dimeric nanostructure is an alternative design for a Localized Surface Plasmon Resonance sensor. At the dimer nanojunction, a high E-field enhancement (hot spot) is observed. In this work, nanostructure size parameters such as aspect ratio, junction, and length of gold dimeric nanorods (AuDNR) linked end-to-end by a thin dielectric junction were evaluated numerically, optimizing the sensing parameters of the plasmonic nanoplatform. The computational approach focused on the assessment of the LSPR extinction spectral peak shift to their local surrounding medium in order to estimate the behavior of sensing parameters such as the figure of merit (FoM), the bulk sensitivity ( η <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> ) and the η <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> × FoM. The nanostructure aspect ratio, junction, and rod length were evaluated, optimizing the plasmonic nanoplatforms sensing parameters. The optimized AuDNR achieved a high sensing performance with η <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> = 544 nm/RIU and FoM = 12.4 RIU <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . Moreover, the obtained η <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> × FoM = 6745.6 nm/RIU <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> is the highest reported value in the literature. For molecular sensing, Campbell's model was explored to evaluate the wavelength shift as a result of molecular adsorption on the nanoparticle surface. We demonstrate that the dimeric nanostructure exhibit twice LSPR peak shift due to a thin molecular adsorption layer rather than a monomer of equivalent size. Our results show that optimized dimeric nanostructure is highly attractive for molecular identification, opening the possibility of establishing new nanoplatforms for medical diagnostic.

중소도시의 물리적 밀집도 분석을 통한 도시재생 관리 유형 연구 - 전라남도 목포시 공간정보 데이터를 중심으로 -

The purpose of this study is to use urban regeneration management types through classification and step-setting of physical types by administrative dong as the basis data for future urban management plans in local small and medium cities. The analysis was conducted on the physical density of each administrative dong by setting the data on urban and architecture provided by the government as three elements: buildings, lots, roads, etc. Through the system classified in this study, Mokpo City's 23 administrative districts were divided into nine management types and three management steps. Methodology can be utilized to establish areas of similar areas within the city and to use them as basic data for planning management. It is meaningful that it is possible to extract areas that need actual regeneration and maintenance through physical density analysis and plan suitable projects.

Intra-Day Variability Observations of Two Dozens of Blazars at 4.8 GHz

Two dozens of radio loud active galactic nuclei (AGNs) have been observed with Urumqi 25 m radio telescope in order to search for intra-day variability (IDV). The target sources are blazars (namely flat spectrum radio quasars and BL Lac objects) which are mostly selected from the observing list of RadioAstron AGN monitoring campaigns. The observations were carried out at 4.8 GHz in two sessions of 8–12 February 2014 and 7–9 March respectively. We report the data reduction and the first results of observations. The results show that the majority of the blazars exhibit IDV in 99.9% confidence level, some of them show quite strong IDV. We find the strong IDV of blazar 1357 + 769 for the first time. The IDV at centimeter-wavelength is believed to be predominately caused by the scintillation of blazar emission through the local interstellar medium in a few hundreds parsecs away from Sun. No significant correlation between the IDV strength and either redshift or Galactic latitude is found in our sample. The IDV timescale along with source structure and brightness temperature analysis will be presented in a forthcoming paper.

Medium-range order dictates local hardness in bulk metallic glasses

Bulk metallic glasses (BMGs) are materials with outstanding strength and elastic properties that make them tantalizing for engineering applications, yet our poor understanding of how their amorphous atomic arrangements control their broader mechanical properties (hardness, wear, fracture, etc.) impedes our ability to apply materials science principles in their design. In this work, we uncover the hierarchical structure that exists in BMGs across the nano- to microscale by using nanobeam electron diffraction experiments. Our findings reveal that local hardness of microscale domains decreases with increasing size and volume fraction of atomic clusters with higher local medium range order (MRO). Furthermore, we propose a model of ductile phase softening that will enable the future design of BMGs by tuning the MRO size and distribution in the nanostructure.

Resolving the Dust-to-Metals Ratio and CO-to-H2 Conversion Factor in the Nearby Universe

Abstract We investigate the relationship between the dust-to-metals ratio (D/M) and the local interstellar medium environment at ∼2 kpc resolution in five nearby galaxies: IC 342, M31, M33, M101, and NGC 628. A modified blackbody model with a broken power-law emissivity is used to model the dust emission from 100 to 500 μm observed by Herschel. We utilize the metallicity gradient derived from auroral line measurements in H i regions whenever possible. Both archival and new CO rotational line and H i 21 cm maps are adopted to calculate gas surface density, including new wide-field CO and H i maps for IC 342 from IRAM and the VLA, respectively. We experiment with several prescriptions of the CO-to-H2 conversion factor and compare the resulting D/M–metallicity and D/M–density correlations, both of which are expected to be nonnegative from depletion studies. The D/M is sensitive to the choice of the conversion factor. The conversion factor prescriptions based on metallicity only yield too much molecular gas in the center of IC 342 to obtain the expected correlations. Among the prescriptions tested, the one that yields the expected correlations depends on both metallicity and surface density. The 1σ range of the derived D/M spans 0.40–0.58. Compared to chemical evolution models, our measurements suggest that the dust growth timescale is much shorter than the dust destruction timescale. The measured D/M is consistent with the D/M in galaxy-integrated studies derived from infrared dust emission. Meanwhile, the measured D/M is systematically higher than the D/M derived from absorption, which likely indicates a systematic offset between the two methods.

PROPAGATION OF LARGE-SCALE SOLAR WIND EVENTS IN THE OUTER HELIOSPHERE FROM A NUMERICAL MHD SIMULATION

Voyager 1 occasionally detected sudden jumps of the local interstellar magnetic field strength since its heliopause crossing in August 2012. These events were believed to be associated with outward propagating solar wind shocks originating in the inner heliosphere. Here we investigate the correlation between interstellar shocks and large-scale solar wind events by means of numerical MHD simulation. The solar wind is simplified as a symmetric flow near the equatorial plane, and the interstellar neutrals are treated as a constant flow with a fixed density distribution along the upwind direction of the local interstellar medium. The charge exchanges between the solar wind plasma and the interstellar neutrals are taken into account. At a heliocentric distance of 1 AU, the solar wind data from OMNI, STEREO A and B during the period between 2010 and 2017 are used as the inner boundary conditions to drive the simulation. The simulation results showed that the solar wind gradually merges into large-scale structures as the radial distance increases, consistent with observations by New Horizons. After propagating into the inner heliosheath, the shocks are fully developed and the corresponding pressure pulses roughly agree with the observations by Voyager 2 in the inner heliosheath. The arrival of the shocks beyond the heliopause is estimated and found to be consistent with the observed signatures of interstellar shocks by Voyager 1. The possible origins of interstellar shocks in the inner heliosheath are discussed based on the simulation.

Стейкхолдеры региональной экологической политики в России

Abstract Introduction: it is considered that the stakeholders participation in the decision- making process increases their efficiency and effectiveness; however, in the context of studying Russian regional environmental policy, the issue of identification, interests and main directions of interaction between key actors and stakeholders remains under-examined. Objectives: identifying directions and possible forms of cooperation between stakeholders and subjects of Russian regional environmental policy. Methods: classification method. Results: the key stakeholders of Russian regional environmental policy are revealed; the powers of regional authorities in the field of environmental protection are established; the main directions and possible forms of cooperation between stakeholders and subjects of Russian regional environmental policy are specified. Conclusions: there are four key groups of stakeholders that influence the decision-making process in the framework of regional environmental policy (federal government and local authorities, civil society, small, medium and large businesses and universities). Based on the analysis of the regional authorities’ powers, six directionsof cooperation between stakeholders and subjects of Russian regional environmental policy are identified. The most relevant direction for all stakeholders is to ensure environmentally safe waste management; it allows attracting the maximum number of participants and doesn’t require serious financial investments, but mainly only initiative. Possible forms of cooperation between stakeholders and subjects of Russian regional environmental policy are presented for each direction.

Can internal marketing activities save small and medium industrial enterprises in a tough economy Back to the basics approach

Recently, and due to the economic pressure in Jordan, several small and medium enterprises have filed for bankruptcy, or downsized their business leading to the layout of hundreds of employees, which will deepen the economic problems in Jordan and increase the circle of effect. Small and medium enterprises can follow other courses of actions to address such issue. This paper aims to understand the possible impact of internal marketing practices and activities during economic problems on the employees' productivity in small and medium industrial enterprises. In order to achieve this aim, a descriptive analytical methodology was used, quantitative approach through survey strategy was applied and electronically administrated questionnaires were utilised to collect the primary data from a representative stratified random sample of 490 small and medium industrial enterprises out of 2,291 registered local small and medium industrial enterprises. 345 filtered and screened questionnaires were analysed using SPSS, the main results of simple and multiple regression analyses indicate that internal marketing mix has a strong positive direct effect on employees' productivity, where internal promotion has the most effect followed by workplace, internal product and internal price respectively. Discussion, conclusion, and recommendations are provided based on the results of the study.

Effects of Dispersion of the Dust Velocity in the LISM on the Interstellar Dust Distribution inside the Heliosphere

Interstellar dust (ISD) penetrates into the heliosphere due to the relative motion of the Sun and the local interstellar medium (LISM). Inside the heliosphere and at the boundaries, where solar wind interacts with the LISM, distribution of ISD is modified due to the action of the electromagnetic forces, the solar gravitation and the radiation pressure. These forces make the distribution of the ISD particles in the heliosphere inhomogeneous. In previous work we demonstrated the existence of singularities in the ISD density distribution at 0.03 - 10 a.u. north and south with respect to the heliospheric current sheet. In this paper we show that dispersion in the ISD velocity distribution strongly affects the singularities. Even small values of dispersion have the drastic impact on the density distribution and smooth the high density layers discovered previously.

Waves and Turbulence in the Very Local Interstellar Medium: From Macroscales to Microscales

Abstract Voyager 1 (V1) has been exploring the heliospheric boundary layer in the very local interstellar medium (VLISM) since 2012 August. The measurements revealed a spectrum of fluctuations over a vast range of space and timescales, but the nature of these fluctuations continues to be an intriguing question. Numerous manifestations of turbulence cannot be explained using a single phenomenology. Weak shocks and compressions are the prominent features of the VLISM. We use high-resolution (48 s) measurements to perform a multiscale analysis of turbulence at V1 between the years of 2013.36 and 2019.0 (124–144 au from the Sun). On relatively large scales, wave trains of mixed compressible/transverse nature with the correlation scale in the range of 15–100 days dominate the spectrum of fluctuations. The observed magnetic field profiles are suggestive of a Burgers-like (f −2) turbulence phenomenology induced by solar activity. We demonstrate that the level of large-scale compressible fluctuations is still significant in late 2018. We analyze the turbulence down to small scales comparable to the ion inertial length and show that magnetic compressibility is always large on these scales. Besides the shock-induced turbulence measured from 2014.486, the intensity and intermittency of small-scale fluctuations have been growing smoothly since 2018.5. Our analysis suggests that local processes are contributing to the production of turbulence on small scales. We present the estimates of transport coefficients in the plasma traversed by V1. The range of scales is identified where V1 measurements are affected by the contribution from pickup ions.

Торгівля структурованими фінансовими продуктами та перспективи її впровадження в нових економіках

The main objective of the research is to examine key aspects of the structured trade financing instruments and to analyze prerequisites for its existence. Hereby, the main focus is concentrated around developing economies. The research was carried out based on research methods such as comparative analysis, empirical approaches and logical generalization. Also, for the research purposes the current market situation, infrastructure, opinions and recommendations of international organizations were analyzed, and an optimal model and market conditions were generated. As a result of research an importance of the derivative financial instruments, organization of spot markets and warehouse receipt systems were investigated. The main factor limiting the study is a variable statistical need and mathematical modeling based on the economic specifications of each economy. As each market will need more country-oriented research and solution rather than general model that suits all. The practical significance of the research is to ensure synergies between financial and commodity markets and to develop a sustainable risk management tool, enhance access to capital by introducing an alternative financial instrument and market environment for local producers, including small and medium size entrepreneurs.

Structured financial producs trading and it's implementation perspectives in emerging economies

The main objective of the research is to examine key aspects of the structured trade financing instruments and to analyze prerequisites for its existence. Hereby, the main focus is concentrated around developing economies. The research was carried out based on research methods such as comparative analysis, empirical approaches and logical generalization. Also, for the research purposes the current market situation, infrastructure, opinions and recommendations of international organizations were analyzed, and an optimal model and market conditions were generated. As a result of research an importance of the derivative financial instruments, organization of spot markets and warehouse receipt systems were investigated. The main factor limiting the study is a variable statistical need and mathematical modeling based on the economic specifications of each economy. As each market will need more country-oriented research and solution rather than general model that suits all. The practical significance of the research is to ensure synergies between financial and commodity markets and to develop a sustainable risk management tool, enhance access to capital by introducing an alternative financial instrument and market environment for local producers, including small and medium size entrepreneurs.

A Laboratory Investigation To Remove The Responsible For Clogging In Filtration Process

This work was executed to design and construct a scale plant as part of a water treatment process by combining filtration and disinfection in one unit, using the local medium of sand, and a Pulse Electric Field-Low Voltage (PEF-LV). The Existing Rapid Sand Filtration (ERSF) is a purely physical method of drinking water purification. Biofilm formation takes place in the sand medium and comprises three steps i) bacterial cells settle onto the sand medium, ii) cells proliferate and secrete adhesive Extracellular Polymeric Substrates (EPS) and iii) cells detach and spread the biofilm to new locations, forming a soapy substance. In this study, we attempted to modify the ERSF by overcoming the drawbacks, in terms of the quality of the filtered water, EPS removal, as well as ease of operation–maintenance to make it more sustainable. The Disinfectant of Rapid Sand Filter (DRSF) incorporates the Pulse Electric Field-Low Voltage through the electrodes between the media. The experiments were done over the period from December 2019 to July 2020, at 8 hr/day as the running time The effectiveness of the various operational conditions of the DRSF and their findings were also analyzed, together with the observational, experimental and theoretical basis. The results showed that the optimum conditions for better performance of the DRSF include 30V, 3 pulses/second, AC pulse frequency, 50Hz, two pairs of electrodes in the sand medium, 100 L/hr influent flow rate, and parallel connection. Backwashing requirements for the ERSF was necessary every day, but in DRSF it was only once in every 7 days, at the same influent flow rates of 100 L/hr. Therefore, as the DRSF is to be backwashed less frequently, the operation and maintenance difficulties will be greatly minimized. The EPS, which was produced by the bacteria, was responsible for clogging the medium and causing the necessity to backwash every day in the ERSF. This microbial biomass reduced the pore space in the medium and increased the head loss. • Combining of filtration and disinfection in one unit (DF). • PEF-LV is an alternate water disinfection technology designed to avoid the use of chlorine. • Removal the responsible for clogging in the sand media (EPS). • Reduce the frequency of backwashing.

New insights into the WR nebula M1-67 with SITELLE

ABSTRACT We present a detailed study of M1-67, a well-known nebula around the population I Wolf–Rayet star WR 124 (WNh 8), based on datacubes obtained with the imaging Fourier transform spectrometer SITELLE at the Canada–France–Hawaii Telescope. This allowed us to reconstruct detailed emission-line ratio maps that highlight clear orthogonal features from a chemical abundance point of view, a complete extinction map, as well as the electron density and temperature structures. In addition to this information, velocity maps were obtained shedding light on the bow shock structure due to the high velocity of WR124, qualified as a runaway star, which is about +190 km s−1 relative to the local interstellar medium. Interaction between the latter structure and spherical and non-spherical outburst could explain the global morphology of M1-67.