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In this study, we present ionospheric observations of field‐aligned currents from AMPERE and the ESA Swarm A satellite, in conjunction with high‐resolution thermospheric density measurements from accelerometers on board Swarm C and GRACE‐FO, for the third and 4 February 2022 geomagnetic storms that led to the loss of 38 Starlink internet satellites. We study the global storm time response of the thermospheric density enhancements, including their decay and latitudinal distribution. We find that the thermospheric density enhances globally in response to high‐latitude energy input from the magnetosphere‐solar wind system and takes at least a full day to recover to pre‐storm density levels. We also find that the greatest density perturbations occur at polar latitudes consistent with the magnetosphere‐ionosphere dayside cusp, and that there appeared to be a saturation of the thermospheric density during the geomagnetic storm on the fourth. Our results highlight the critical importance of high‐latitude ionospheric observations when diagnosing potentially hazardous conditions for low‐Earth‐orbit satellites. Plain Language Summary: Upwards of a 100 km altitude lies the boundary between Earth's atmosphere and space, where the density of air exponentially decreases and many satellites constellations orbit. One of these constellations is Starlink, which provides satellite internet to customers on Earth. In February 2022, a pair of geomagnetic storms stuck Earth shortly after the launch of 49 Starlink satellites, heating the upper atmosphere and causing its density to drastically increase. The higher air density at the initial staging altitude of Starlink caused fatal drag conditions for 38 of the spacecraft, resulting in their destruction a few days later. This paper examines how the air density of the upper atmosphere changed globally in response to space weather energy being deposited at high latitudes during the Starlink geomagnetic storms of February 2022. Key Points: Ionospheric field‐aligned current and thermospheric neutral densities are examined for the 2022 Starlink geomagnetic stormsThe field‐aligned currents changed quickly, whilst the density decayed slowly and with differing timescalesAsymmetric latitudinal density distributions are consistent with asymmetries in the field aligned currents [ABSTRACT FROM AUTHOR]

Abstract In this study, we present ionospheric observations of field‐aligned currents from AMPERE and the ESA Swarm A satellite, in conjunction with high‐resolution thermospheric density measurements from accelerometers on board Swarm C and GRACE‐FO, for the third and 4 February 2022 geomagnetic storms that led to the loss of 38 Starlink internet satellites. We study the global storm time response of the thermospheric density enhancements, including their decay and latitudinal distribution. We find that the thermospheric density enhances globally in response to high‐latitude energy input from the magnetosphere‐solar wind system and takes at least a full day to recover to pre‐storm density levels. We also find that the greatest density perturbations occur at polar latitudes consistent with the magnetosphere‐ionosphere dayside cusp, and that there appeared to be a saturation of the thermospheric density during the geomagnetic storm on the fourth. Our results highlight the critical importance of high‐latitude ionospheric observations when diagnosing potentially hazardous conditions for low‐Earth‐orbit satellites.

Magnetic reconnection occurring between the interplanetary magnetic field (IMF) and the dayside magnetopause causes a circulation of magnetic flux and plasma within the magnetosphere, known as the Dungey cycle. This circulation is transmitted to the ionosphere via field‐aligned currents (FACs). The magnetic flux transport within the Dungey cycle is quantified by the cross‐polar cap potential (CPCP or transpolar voltage). Previous studies have suggested that under strong driving conditions the CPCP can saturate near a value of 250 kV. In this study we investigate whether an analogous saturation occurs in the magnitudes of the FACs, using observations from the Active Magnetosphere and Planetary Electrodynamics Response Experiment. The solar wind speed, density and pressure, the Bz component of the IMF, and combinations of these, were compared to the concurrent integrated current magnitude, across each hemisphere. We find that FAC magnitudes are controlled most strongly by solar wind speed and the orientation and strength of the IMF. FAC magnitude increases monotonically with solar wind driving but there is a distinct knee in the variation around IMF Bz = −10 nT, above which the increase slows. Plain Language Summary: During extreme space weather events, the threat to space‐based and surface infrastructure has become of increasing concern within the past 2 decades. These space weather events are directly responsible for electrical currents flowing in the ionosphere that produce potentially dangerous magnetic field perturbations on the ground. With this motivation, we use satellite magnetometer data in order to gain greater insight into the field aligned current systems present above both poles of the Earth. With many mechanisms and processes which govern the magnitude of these currents (and associated potentials) still being widely disputed, we hope to offer verification of whether or not these currents saturate at high solar wind driving, in order to create a clearer picture of the behavior of these systems from nominal to intense space weather conditions. Key Points: The field‐aligned current (FAC) flow increases with increasing southward interplanetary magnetic field (IMF) BzThere is a steeper gradient of increase for IMF Bz values below −10 nT than for that above 10 nT, for all local timesFeatures of polar cap potential saturation are observed in FAC data during strong southward IMF [ABSTRACT FROM AUTHOR]

Tensor Cores have been an important unit to accelerate Fused Matrix Multiplication Accumulation (MMA) in all NVIDIA GPUs since Volta Architecture. To program Tensor Cores, users have to use either legacy wmma APIs or current mma APIs. Legacy wmma APIs are more easy-to-use but can only exploit limited features and power of Tensor Cores. Specifically, wmma APIs support fewer operand shapes and can not leverage the new sparse matrix multiplication feature of the newest Ampere Tensor Cores. However, the performance of current programming interface has not been well explored. Furthermore, the computation numeric behaviors of low-precision floating points (TF32, BF16, and FP16) supported by the newest Ampere Tensor Cores are also mysterious. In this paper, we explore the throughput and latency of current programming APIs. We also intuitively study the numeric behaviors of Tensor Cores MMA and profile the intermediate operations including multiplication, addition of inner product, and accumulation. All codes used in this work can be found in https://github.com/sunlex0717/DissectingTensorCores. [ABSTRACT FROM AUTHOR]

Los inicios de la educación agrícola en el mundo datan de 1772 cuando se funda una escuela elemental en la región de Bohemia donde se impartía formación en cultivos y cuidado de animales. Sin embargo, la educación superior agrícola surge en 1790 en la Universidad de Edimburgo (Inglaterra) cuando se crea la primera cátedra en agricultura. Para inicios del siglo XIX ya circulaban en Europa muchos conceptos científicos y técnicos en muchas áreas del conocimiento que, en concepto de Marie Ampère, requerían ser organizados sistemáticamente. Es así como entre 1831 y 1832, presenta una propuesta de clasificación sistemática de las ciencias y ve la necesidad de crear una nueva ciencia que tenga que ver con los animales desde el punto de vista de su utilidad a los hombres que denomina Zootecnia. En 1874 en Bogotá, se crea la primera Escuela Agrícola del país mientras que en 1880 se crea el Instituto Agrícola Nacional. Sin embargo, ambas instituciones desaparecieron rápidamente en medio de los avatares de las guerras civiles. No fue sino hasta 1914 cuando la Asamblea Departamental de Antioquia aprueba la creación de la Escuela de Agricultura Tropical y Veterinaria, que da inicio a la formación en ciencias agrarias en Colombia de manera permanente. Esta Escuela se fue trasformando hasta convertirse en la Facultad Nacional de Agronomía que fue adscrita a la Universidad Nacional en 1938 y en donde surge la Zootecnia 1962 como profesión. [ABSTRACT FROM AUTHOR]

This study investigates the field‐aligned currents (FACs) and ionospheric equivalent currents for interplanetary coronal mass ejection (ICME)‐driven storms by considering 45 events with a minimum Dst ≤ −50 nT. The FACs and ionospheric equivalent currents are studied by applying a superposed epoch analysis to data from AMPERE and SuperMAG with the zero epoch (t0) centered at the onset of the storm main phase. The currents and number of substorm onsets begin to increase 3 hr before t0 and maximizes about 1 hr after t0. The currents and number of substorm onsets remain high throughout the entire storm main phase, until at t0 + 14 hr they start to slowly relax back to quiet time conditions. The storms were separated into two groups based on the solar wind dynamic pressure pdyn around t0. High pdyn storms are mostly driven by the sheath region ahead of the ejecta. These storms have short main phase durations and larger currents early in the main phase which maximize at t0 + 50 min. The low pdyn group contains storms that start during the magnetic clouds (MC) and have gradually increasing currents that maximize at t0 + 11 hr, close to the end of the storm main phase. For the first 4 hr of the storm main phase, the currents in sheath‐driven storms are larger than for MC‐driven storms. The Russell‐McPherron effect is less important for ICME‐driven storms where only 44% have a contribution, compared to 82% of high speed stream/stream interaction driven storms. Plain Language Summary: Geomagnetic storms are responsible for the largest magnetospheric and ionospheric disturbances and can last up to several days. During storms, field‐aligned currents (FACs) that couple the magnetosphere and the ionosphere intensify, increasing in magnitude by millions of ampere and are connected to large enhancements in the horizontally flowing ionospheric currents. In this study, the FACs and ionospheric currents have been studied statistically using data from 45 interplanetary coronal mass ejection (ICME) driven storms. It is found that the currents peak about 1 hr after the storm main phase onset and remain strongly intensified for the next 14 hr, before slowly decreasing back to normal time conditions. It is also shown that the solar wind dynamic pressure can to a large extent separate storms driven by the sheath region versus magnetic cloud (MC) region of the ICME. Sheath‐driven storms have an abrupt increase in the currents shortly after the storm main phase onset, while MC‐driven storms have gradual increase in currents that reach maximum 11 hr after onset. Sheath‐driven storms drive larger currents than MC‐driven storms for the first 4 hr after main phase onset. Afterward, the currents become larger for MC than sheath‐driven storms. Key Points: High pdyn storms are mainly driven by sheath regions ahead of the interplanetary coronal mass ejection (ICME) ejecta and low pdyn storms are mainly driven by magnetic clouds (MC)Sheath (high pdyn) storms have field‐aligned current (FAC) that peak 1 hr after t0, while MC (low pdyn) storms develop gradually and have FAC that peak 11 hr after t0Russell‐McPherron effect is less frequently observed in ICME storms (44%) than in high speed streams/stream interaction regions storms (82%) [ABSTRACT FROM AUTHOR]

The hard facing process is the welding process of SMAW by using a hard facing DIN 888 electrode as a hard facing to replace conventional cutting tool material. Research method is designed using factorial experiment design with 2 factors, 3 levels, and 4 iterations. The purpose of this analysis is to determine the effect of preheating temperature on the welding of hard coatings on AISI A35 low carbon steel. The results of this study are expected to obtain optimum hardness on coated steel, from variations in the temperature of the preheating. there will be a change in the hardness of the welding deposit, the deposit will be used as cutting tools. The results of this study can be used as guidelines for making cutting tools.

We present a statistical analysis of the occurrence of bifurcations of the Region 2 (R2) Field-Aligned Current (FAC) region, observed by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). Previously, these have been shown to occur as the polar cap contracts after substorm onset, the beginning of the growth phase. During this phase both the Region 1 (R1) and R2 currents move equatorwards as the polar cap expands. Following onset, the R1 FAC region contracts polewards but the R2 FAC continues to expand equatorwards before eventually fading. At the same time, a new R2 FAC develops equatorwards of the R1 FAC. We have proposed that the bifurcated FACs formed during substorms are associated with plasma injections from the magnetotail into the inner magnetosphere, and that they might be the FAC signature associated with Sub-Auroral Polarization Streams (SAPS). We investigate the seasonal dependence of the occurrence of bifurcations from 2010 to 2016, determining whether they occur predominantly at dawn or dusk. Region 2 Bifurcations (R2Bs) are observed most frequently in the summer hemisphere and at dusk, and we discuss the possible influence of ionospheric conductance. We also discuss a newly discovered UT dependence of the R2B occurrences between 2011 and 2014. This dependence is characterized by broad peaks in occurrence near 09 and 21 UT in both hemispheres. Reasons for such a preference in occurrence are explored.

For over a decade, the Super Dual Auroral Radar Network and the Active Magnetosphere and Planetary Electrodynamics Response Experiment have been measuring ionospheric convection and field‐aligned currents in the high‐latitude regions, respectively. Using both, high‐latitude maps of the magnetosphere‐ionosphere energy transfer rate (the Poynting flux) have been generated with a time resolution of 2 min between 2010 and 2017. These data driven Poynting flux (PF) patterns are used in this study to perform a superposed epoch analysis of the northern hemisphere ionospheric response to transitions of the interplanetary magnetic field Bz component, upwards of 60° geomagnetic latitude. We discuss the difference in the distribution of PF between the magnetosphere‐ionosphere Dungey cycle "switching on" and "switching off" to solar wind driving, revealing that they are not symmetric temporally or spatially. Plain Language Summary: The Earth's high‐latitude upper atmosphere (the ionosphere, upwards of 100 km in altitude) is consistently bombarded with solar energy that takes the form of electric currents aligned with Earth's magnetic field. The magnetosphere has two generalized states, "open" and "closed." Open is when the Earth and interplanetary magnetic fields (IMFs) connect to each other on the dayside, allowing energy into the atmosphere from the solar wind. Closed is when the fields do not connect (or do not connect simply) and thus not as much energy enters the atmosphere. The aforementioned open or closed states depend on the direction of the IMF, which varies constantly, as well as the history of the field as the magnetosphere takes time to reconfigure. In this study, we utilize nearly 8 years of data to generate average patterns of ionospheric energy input at various intervals before and after the IMF flips in direction. We discuss the spatial and temporal timescales upon which the energy varies in response to the relatively symmetric IMF transitions, finding that they do not result in symmetric changes in the ionospheric energy input patterns. Key Points: The Super Dual Auroral Radar Network and the Active Magnetosphere and Planetary Electrodynamics Response Experiment derived Poynting flux (PF) distributions are used to perform a superposed epoch analysis of interplanetary magnetic field (IMF) Bz transitionsChanges in the IMF Bz component have immediate responses, but continue to evolve for several tens of minutesThere is spatial and temporal asymmetry to how the PF morphology responds to opposite Bz transitions [ABSTRACT FROM AUTHOR]

This study considers 28 geomagnetic storms with Dst ≤−50 nT driven by high‐speed streams (HSSs) and associated stream interaction regions (SIRs) during 2010–2017. Their impact on ionospheric horizontal and field‐aligned currents (FACs) have been investigated using superposed epoch analysis of SuperMAG and AMPERE data, respectively. The zero epoch (t0) was set to the onset of the storm main phase. Storms begin in the SIR with enhanced solar wind density and compressed southward oriented magnetic field. The integrated FAC and equivalent currents maximize 40 and 58 min after t0, respectively, followed by a small peak in the middle of the main phase (t0 + 4 hr), and a slightly larger peak just before the Dst minimum (t0 + 5.3 hr). The currents are strongly driven by the solar wind, and the correlation between the Akasofu ε and integrated FAC is 0.90. The number of substorm onsets maximizes near t0. The storms were also separated into two groups based on the solar wind dynamic pressure pdyn in the vicinity of the SIR. High pdyn storms reach solar wind velocity maxima earlier and have shorter lead times from the HSS arrival to storm onset compared with low pdyn events. The high pdyn events also have sudden storm commencements, stronger solar wind driving and ionospheric response at t0, and are primarily responsible for the first peak in the currents after t0. After t0+2 days, the currents and number of substorm onsets become higher for low compared with high pdyn events, which may be related to higher solar wind speed. Plain Language Summary: Solar wind emanating from solar coronal holes tend to have faster velocity than the ambient solar wind and can together with southward oriented interplanetary magnetic field lead to geomagnetic storms in geospace. We have studied 28 geomagnetic storms of this kind and analyzed the behavior of the field‐aligned currents and ionospheric horizontal currents in the high latitude auroral region with respect to the onset of the geomagnetic storms. The total current maximizes just 40 min after the storm onset, followed by two smaller peaks in the middle and end of the storm main phase. The correlation between the total field‐aligned current and the predicted solar wind‐magnetosphere coupling is very high, 0.90, and indicates that the currents are strongly driven by the solar wind. We also split the storms into two groups based on the solar wind dynamic pressure at the onset of the storms. Several characteristic differences are found between the two groups, for example, high pressure storms are largely responsible for the first peak in the currents and have shorter lead time between the coronal hole solar wind is detected by upstream satellites and the onset of the storm. These findings could help improve space weather predictions. Key Points: The integrated field‐aligned current and equivalent currents peak 40 and 58 min after storm onset, respectivelyThe currents are strongly driven by the solar wind as indicated by the ε parameter and the correlation coefficient between ε and FAC is 0.90High pdyn storms produce storm sudden commencements, larger solar wind coupling, the first peak in auroral currents, and a longer recovery phase than low pdyn storms [ABSTRACT FROM AUTHOR]

J. Bertrand costuma ser conhecido por suas contribuições para a mecânica e para a matemática, mas pouco se sabe sobre sua predileção para a eletrodinâmica. Assim, de maneira inédita, apresentamos a contextualização e a tradução comentada, do francês para o português, do artigo “Demonstração dos teoremas relativos às ações eletrodinâmicas”. Nesse artigo, Bertrand deduz catorze teoremas fundamentais da eletrodinâmica. Entre outros pontos, tece considerações a respeito da validade da 3a lei de Newton na eletrodinâmica, deduz a Força de Ampère de apenas dois fatos experimentais – diminuindo o número dos casos de equilíbrio necessários de quatro para dois – obtém o teorema equivalente ao divergente do campo magnético (uma das equações de Maxwell), faz considerações sobre o potencial eletrodinâmico, e deduz a relação entre um dipolo magnético e um circuito fechado plano.

We interviewed Marco Nisi, Aerospace Engineer currently employed as a consultant for project management activities coordinating European consortia with a main focus on satellite communication (SATCOM) and navigation (NAVCOM) applied to the energy, security, aeronautics and maritime sectors. [ABSTRACT FROM AUTHOR]

Large thermospheric neutral density enhancements in the cusp region have been examined for many years. The Challenging Minisatellite Payload (CHAMP) satellite for example has enabled many observations of the perturbation, showing that it is mesoscale in size and exists statistically over solar cycle timescales. Further studies examining the relationship with magnetospheric energy input have shown that fine‐scale Poynting fluxes are associated with the density perturbations on a case‐by‐case basis, whilst others have found that mesoscale downward fluxes also exist in the cusp region statistically. In this study, we use nearly 8 years of the overlapping Super Dual Auroral Radar Network and Active Magnetosphere and Planetary Electrodynamics Response Experiment datasets to generate global‐scale patterns of the high‐latitude and height‐integrated Poynting flux into the ionosphere, with a time resolution of 2 min. From these, average patterns are generated based on the interplanetary magnetic field orientation. We show the cusp is indeed an important feature in the Poynting flux maps, but the magnitude does not correlate well with statistical neutral mass density perturbations observed by the CHAMP satellite on similar spatial scales. Importantly, the lack of correlation between mesoscale height‐integrated Poynting fluxes and the cusp neutral mass density enhancement gives possible insight into other processes that may account for the discrepancy, such as energy deposition at finer scale sizes or at higher altitudes than captured. Key Points: Statistical patterns of the total downward Poynting flux into the atmosphere have been derived using Super Dual Auroral Radar Network and Active Magnetosphere and Planetary Electrodynamics Response Experiment dataStatistical patterns of neutral mass density perturbations as a percentage of the background density have been derived using Challenging Minisatellite Payload dataMesoscale downward Poynting flux in the cusp region do not correlate very well with neutral mass density enhancements at a similar scale [ABSTRACT FROM AUTHOR]

GNSS and Unmanned Aerial Systems (UASs) are a winning synergy in many applications: remote sensing, security, mapping, surveillance, and logistics. [ABSTRACT FROM AUTHOR]

Two‐dimensional thermospheric wind fields, at both E and F region altitudes within a common vertical volume, were made using a Scanning Doppler Imager (SDI) at Poker Flat, Alaska, during a substorm event. Coinciding with these observations were F region plasma velocity measurements from the Super Dual Auroral Radar Network (SuperDARN) and estimations of the total downward and upward field‐aligned current density from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). This combination of instruments gives an excellent opportunity to examine the spatial characteristics of high‐latitude ionosphere‐thermosphere coupling and how a process which is triggered in the magnetosphere (the substorm) affects that coupling at different altitudes. We find that during the substorm growth phase, the F region thermospheric winds respond readily to an expanding ionospheric plasma convection pattern, while the E region winds appear to take a much longer period of time. The differing response timescales of the E and F region winds are likely due to differences in neutral density at those altitudes, resulting in E region neutrals being much more "sluggish" with regard to ion drag. We also observe increases in the F region neutral temperature, associated with neutral winds accelerating during both substorm growth and recovery phases. Plain Language Summary: At different altitudes in the polar atmosphere, how charged particles (the ionosphere) interact with neutral particles (the thermosphere) is of great importance. Primarily, this is because collisions between the two is the mechanism by which energy from the solar wind is ultimately deposited into the atmosphere, from the magnetosphere. Magnetosphere‐thermosphere energy exchange drives auroral displays and contributes to heating in both the E region (altitudes between 100 and 130 km) and F region (altitudes between 150 and 300 km). The neutral atmosphere is significantly denser in the E region compared to the F region, so its interaction with the ionosphere at those different altitudes is quite different. In this study, we examined the E and F regions during a "substorm" event, which is a large, sudden injection of energy into the nightside ionosphere. We found that the velocity of neutrals in the E region reacted much more slowly than those in the F region, so that the conditions imposed on the E region before the substorm persisted during the substorm. Key Points: Ionosphere‐thermosphere coupling is examined at E and F region altitudes during a substorm, postmidnight above Poker Flat, AlaskaE region neutral winds are found to react slower to changes in the ionsophere due to substorm phases, compared to the F regionF region heating is observed and associated with neutral wind acceleration during substorm growth and recovery [ABSTRACT FROM AUTHOR]

The existence of Birkeland magnetic field‐aligned current (FAC) system was proposed more than a century ago, and it has been of immense interest for investigating the nature of solar wind‐magnetosphere‐ionosphere coupling ever since. In this paper, we present the first application of deep learning architecture for modeling the Birkeland currents using data from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). The model uses a 1‐hr time history of several different parameters such as interplanetary magnetic field (IMF), solar wind, and geomagnetic and solar indices as inputs to determine the global distribution of Birkeland currents in the Northern Hemisphere. We present a comparison between our model and bin‐averaged statistical patterns under steady IMF conditions and also when the IMF is variable. Our deep learning model shows good agreement with the bin‐averaged patterns, capturing several prominent large‐scale features such as the Regions 1 and 2 FACs, the NBZ current system, and the cusp currents along with their seasonal variations. However, when IMF and solar wind conditions are not stable, our model provides a more accurate view of the time‐dependent evolution of Birkeland currents. The reconfiguration of the FACs following an abrupt change in IMF orientation can be traced in its details. The magnitude of FACs is found to evolve with e‐folding times that vary with season and MLT. When IMF Bz turns southward after a prolonged northward orientation, NBZ currents decay exponentially with an e‐folding time of ∼25 min, whereas Region 1 currents grow with an e‐folding time of 6–20 min depending on the MLT. Key Points: We developed the first deep learning model to predict the dynamics of AMPERE‐derived field aligned currentsWhen IMF changes abruptly, the initial response and total reconfiguration time of FACs vary with MLT and seasonFor an abrupt change in IMF Bz or By, our model predicts an exponential response in FACs [ABSTRACT FROM AUTHOR]

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We present high‐latitude field‐aligned current (FAC) response to nearly frontal shocks (NFSs) and highly inclined shocks (HISs) through a superposed epoch analysis. The FACs are derived from magnetic perturbation data provided by the Active Magnetosphere and Planetary Electrodynamics Response Experiment program. Forty‐nine events for each group are used for the superposed epoch analysis. The 25%, 50%, and 75% quantiles of the FAC and total current distributions are studied. We found that NFSs are statistically stronger shocks in terms of solar wind parameters such as solar wind speed and interplanetary magnetic field.For the 50% quantiles, both groups of shocks produce rapid increases in total currents after shock arrival, but NFSs result in sharper increase in FACs and more intense FACs compared to HISs. At the 50% and 75% quantiles, NFSs trigger stronger auroral‐zone current disturbance for the first hour after shock arrival than do HISs. Spatially, the difference in FAC response is most notable in (1) the dayside noon region, (2) the duskside Region 2 current system, and (3) the dawnside prenoon Region 1 current system. Our results are consistent with previous numerical simulations that showed more symmetric and stronger compression of the magnetosphere for high‐speed and nearly frontal shocks. We observationally confirm the role of shock impact angle in controlling the subsequent shock geoeffectiveness for fast shocks. We assert that determining the shock impact angle via an upstream solar wind model could provide useful insight in forecasting the geoeffectiveness of a shock prior to its arrival at the magnetopause. Key Points: Fast, nearly frontal shocks result in sharper increase in FACs and more intense FACs in the first hour after shock arrivalNearly frontal shocks are generally stronger interplanetary shocks compared to highly inclined shocks in terms of solar wind parametersClearest spatial response difference between NFSs and HISs shows around noon, duskside R2 currents and pre‐noon R1 currents [ABSTRACT FROM AUTHOR]

O objetivo deste trabalho é analisar a inserção de Ampére – Paraná na rede urbana a partir da dinâmica de seu setor produtivo. Ampére é um centro local inserido na rede urbana de Francisco Beltrão – PR, localizada na mesorregião Sudoeste Paranaense. Rede esta que se torna cada vez mais complexa e, essa complexidade se amplia à medida que se amplia a divisão territorial do trabalho, o que, possibilita que um centro local mantenha relações não apenas com a rede urbana estruturada pela teoria das localidades centrais, mas se estruturam, ao mesmo tempo, em outra rede urbana, deste modo, um dos aspectos desta complexidade diz respeito ao fato de cada cidade situar-se em pelo menos duas redes. Por exemplo, Ampére mesmo sendo um centro local na área de influência de Francisco Beltrão nos anos 1960 e 1970, cuja dinâmica era dada, sobretudo, pela distribuição da produção rural de bens e serviços, foi nos anos 1990 e 2000 se transformando em um centro especializado na produção industrial de móveis e confecções. Deste modo, a cidade se inseriu em diversas relações que dão conta da aquisição de matérias-primas, fluxos de mão de obra, produção, distribuição da produção que alcançam todos os Estados brasileiros e uma pequena parte da produção é encaminhada para o mercado externo, não nos esquecendo, ainda que, tais relações produzem fluxos de todas as ordens, sobretudo financeiros, responsáveis, principalmente, por manter a dinâmica econômica do centro urbano.

The paper presents an original method for contactless express measurement of parameters of thermoelectric materials. The presence of a combination of AC and DC magnetic fields in the gap of the oscillating circuit, where the monitored sample of the thermoelectric material is located, leads — due to Ampere force — to delamination of geometric regions of the occurrence of half-cycles of Foucault current. This in turn causes the appearance of additional heat losses in the oscillating circuit caused by Peltier effect. Computer modeling of these processes with the use of the software package ComsolFenlab 3.3 allowed determining the nature and magnitude of the electric currents in oscillating circuit, the range of operating frequencies, and the ratio of amplitudes of the variable and fixed components of the magnetic field. These components eventually cause a certain temperature difference along the controlled sample, which difference is proportional to the thermoelectric figure of merit Z of the material. The basic expressions are obtained for determining the value of the Seebeck coefficient a, thermal conductivity ?, electrical conductivity ? and thermoelectric figure of merit Z. A description is given to the design of the device for contactless express measurement of parameters of thermoelectric materials based on Bi—Te—Se—Sb solid solutions. Its distinctive feature is the ability to determine the symmetric and asymmetric components of the electric conductivity of the material values. The actual error in parameter measurement in this case is 2%.

By fixing two fundamental constants from quantum mechanics, the Planck constant h and the elementary charge e , the revised "Système international" (SI) of units endorses explicitly quantum mechanics. This evolution also highlights the importance of this theory that underpins the most accurate realizations of the units. From 20 May 2019 onwards, the new definitions of the kilogram and of the ampere, based on fixed values of h and e , respectively, will particularly impact the electrical metrology. The Josephson effect (JE) and the quantum Hall effect (QHE), used to maintain voltage and resistance standards with unprecedented reproducibility since 1990, will henceforth provide realizations of the volt and the ohm without the uncertainties inherited from the older electromechanical definitions. More broadly, the revised SI will support the exploitation of quantum effects to realize the electrical units, to the benefit of end-users. Here, we review the state-of-the-art of quantum standards and discuss further applications and perspectives in electrical metrology. [ABSTRACT FROM AUTHOR]

The ability to study of growth curve by new principle, it use ampere which transfer during culture media to measure bacterial growth curve. This new technique of detection growth curve dependent on quantity of acidic (pH concentration) and ampere measurement which formed due to growing of bacteria in culture media, program was used to measure of ampere and draw of growth curve on computer (mAmp or mlAmp) pre (second or minute) dependent on type of bacteria. This principle repaired the errors in classic method, which study the growth curve, prevent any contamination with growth and obtain of really growth curve without any factor was affected in growth curve such as (time, bacterial products and contamination). [ABSTRACT FROM AUTHOR]

Abstract: Field‐aligned currents (FACs), also known as Birkeland currents, are the agents by which energy and momentum are transferred to the ionosphere from the magnetosphere and solar wind. This coupling is enhanced at substorm onset through the formation of the substorm current wedge. Using FAC data from the Active Magnetosphere and Planetary Electrodynamics Response Experiment and substorm expansion phase onsets identified using the Substorm Onsets and Phases from Indices of the Electrojet technique, we examine the Northern Hemisphere FACs in all local time sectors with respect to substorm onset and subdivided by season. Our results show that while there is a strong seasonal dependence on the underlying FACs, the increase in FACs following substorm onset only varies by 10% with season, with substorms increasing the hemispheric FACs by 420 kA on average. Over an hour prior to substorm onset, the dayside currents in the postnoon quadrant increase linearly, whereas the nightside currents show a linear increase starting 20–30 min before onset. After onset, the nightside Region 1, Region 2, and nonlocally closed currents and the SuperMAG AL (SML) index follow the Weimer (1994, https://doi.org/10.1029/93JA02721) model with the same time constants in each season. These results contrast earlier contradictory studies that indicate that substorms are either longer in the summer or decay faster in the summer. Our results imply that, on average, substorm FACs do not change with season but that their relative impact on the coupled magnetosphere‐ionosphere system does due to the changes in the underlying currents. [ABSTRACT FROM AUTHOR]

Calculation peculiarities for Lorentz force, Ampere force, interaction of parallel electric currents, and the moment of electrical machines are analyzed. They have exceptions on application, and they are the rules which result from the law of electromagnetic force as coordinate derivative of the operating magnetic flow. An addition to the direction of electromagnetic force action is proposed. Standards of salient-pole electrical machine designing are considered.