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As silicon electronics approaches the atomic scale, interconnects and circuitry become comparable in size to the active device components. Maintaining low electrical resistivity at this scale is challenging because of the presence of confining surfaces and interfaces. We report on the fabrication of wires in silicon—only one atom tall and four atoms wide—with exceptionally low resistivity (~0.3 milliohm-centimeters) and the current-carrying capabilities of copper. By embedding phosphorus atoms within a silicon crystal with an average spacing of less than 1 nanometer, we achieved a diameter-independent resistivity, which demonstrates ohmic scaling to the atomic limit. Atomistic tight-binding calculations confirm the metallicity of these atomic-scale wires, which pave the way for single-atom device architectures for both classical and quantum information processing.

Ohm’s law has become ubiquitous in numerous scientific and technical disciplines. Generally, the subject is introduced to students in secondary school as fundamental technical knowledge. The present study proposes a visual model to facilitate the comprehension of Ohm’s law in electron transport in solids to pre-university and university students. The objective is to facilitate students’ comprehension of the correlation between electron movement in solids, as depicted by a current, and the energy of the system, which is introduced by the electric field and the material’s structure. The approach’s originality lies in its novel strategy for describing electron trajectory randomization. This enables the establishment of a relationship between the material’s structure and its resistivity. Moreover, the description of electron transport and scattering processes is presented regarding different types of entropy. It shows that electrons follow the maximum trajectory entropy and that thermal entropy has a quadratic relationship with configurational entropy. The determinism of Ohm’s law is inferred from statistical entropy.

We investigate the contribution of the Hall term on the generalized Ohm's law in magnetospheric plasmas. In particular, we focus on its role in processes that lead to the formation of substorm perturbations deep inside the magnetosphere. Using data from the THEMIS mission, we calculate the average Hall length LHall$\\left({L}_{\\text{Hall}}\\right)$and its spatial distribution near the equatorial plane. Our findings reveal that LHall${L}_{\\text{Hall}}$significantly exceeds the ion inertial length, which suggests that the Hall term's contribution to generalized Ohm's law is significantly greater than the convective term. In this case, the magnetic field lines are able to slip through the plasma, something that conventional magnetohydrodynamic models cannot adequately describe. We explore how such slippage facilitates the development of substorm perturbations that do not require changes in magnetic field topology. These perturbations include dipolarization of magnetic field lines, particle acceleration, electrojet formation, and other phenomena typically associated with substorms. Plain Language Summary In this work, we calculate the Hall length, which determines the scale at which magnetic field lines can move through the plasma. We use 12 years of magnetic and particle measurements from NASA's THEMIS mission to determine how this length varies within the magnetosphere. Our results show that the Hall length ranges between thousands and hundreds of thousands of kilometers. These findings suggest that the magnetospheric substorms can be triggered without changes in topology of the magnetic field, which provides new insights into fundamental substorm‐related processes, such as magnetic field line dipolarizations, particle acceleration, and electrojet formation. Key Points The Hall scale distribution in Earth's collisionless magnetospheric plasma was obtained for quiet and disturbed conditions, depending on IMF Bz component The Hall length is found to exceed the characteristic spatial scale of magnetospheric structures in the transverse direction Hall‐scale processes explain key magnetospheric phenomena like IMF penetration to the magnetosphere and dissipation inside inner magnetosphere during substorm

In the prevailing form of the generalized Ohm's law (GOL), −me/e(J/en)⋅∇(J/en)${-}\\left({m}_{e}/e\\right)\\left[(\\boldsymbol{J}/en)\\cdot \\nabla \\right](\\boldsymbol{J}/en)$is often neglected. Because of the resemblance to the magnetic tension, we refer to this term as the current tension electric field (ECT). Our theoretical analysis reveals that ECT with a characteristic length of mi/me1/6λe${\\left({m}_{i}/{m}_{e}\\right)}^{1/6}{\\lambda }_{e}$dominates the electron inertia terms in the electron diffusion region (EDR) and is comparable to the electron pressure term in low‐βe conditions. Using particle‐in‐cell simulations, we demonstrate that ECT can contribute significantly to the reconnection electric field and energy dissipation at the boundaries of the inner EDR and in the outer EDR. Positive and negative J ⋅ ECT can be used to identify inner and outer electron diffusion regions, respectively. Plain Language Summary Magnetic reconnection is a fundamental physical process which allows for the explosive release of magnetic energy into thermal and kinetic energy. It underlies many dynamic phenomena in the universe, including solar eruptions, geomagnetic substorms and tokamak disruptions. In collisionless plasma, the generalized Ohm’s law (GOL) introduces collisionless effects which break the frozen‐in constraint and enable reconnection to occur. The term, −me/e(J/en)⋅∇(J/en)${-}\\left({m}_{e}/e\\right)\\left[(\\boldsymbol{J}/en)\\cdot \\nabla \\right](\\boldsymbol{J}/en)$ , which is one of the electron inertia terms of GOL, is referred to as the current tension electric field (ECT) by us due to its mathematical resemblance to magnetic tension. In many classic textbooks and review papers, ECT is considered as a small quantity and thus is ignored. In this study, we present solid evidence from both theoretical studies and particle‐in‐cell (PIC) simulations to demonstrate that ECT dominates the electron inertia terms and plays important roles in providing reconnection electric field and energy dissipation in reconnection. Therefore, it should not be ignored. Based on our results, many classic textbooks in which ECT has been ignored must be modified. Key Points ECT dominates the electron inertia terms in the electron diffusion region (EDR) and thus cannot be ignored in the generalized Ohm's law ECT contribute significantly to the reconnection electric field and energy dissipation in the inner and outer EDRs Positive and negative J · ECT can be used to identify inner and outer EDRs, respectively

The calibration of low current meters in the range of picoamperes up to microamperes is important for the electronics industry, for the photometry area, and especially for the ionizing radiation area. In Brazil, traceability is limited to ten microamperes. In this paper, a reference system using Ohm’s law method is presented. It was possible to calibrate an electrometer between 2 picoamperes and 20 microamperes, with uncertainties between 0.70 % and 0.000060 %, respectively, as well as to validate the developed system and Ohm’s law method by comparing it with the method used to calibrate values above 10 microamperes, in an intralaboratory comparison.

Background Exposure to electronic-cigarette (e-cig) aerosols induces potentially fatal e-cig or vaping-associated lung injury (EVALI). The cellular and molecular mechanisms underlying these effects, however, are unknown. We used an air–liquid interface (ALI) in vitro model to determine the influence of two design characteristics of third-generation tank-style e-cig devices—resistance and voltage—on (1) e-cig aerosol composition and (2) cellular toxicity. Methods Human bronchial epithelial cells (H292) were exposed to either butter-flavored or cinnamon-flavored e-cig aerosols at the ALI in a Vitrocell exposure system connected to a third-generation e-cig device. Exposures were conducted following a standard vaping topography profile for 2 h per day, for 1 or 3 consecutive days. 24 h after ALI exposures cellular and molecular outcomes were assessed. Results We found that butter-flavored e-cig aerosol produced under ‘sub-ohm’ conditions (< 0.5 Ω) contains high levels of carbonyls (7–15 μg/puff), including formaldehyde, acetaldehyde and acrolein. E-cig aerosol produced under regular vaping conditions (resistance > 1 Ω and voltage > 4.5 V), contains lower carbonyl levels (< 2 μg/puff). We also found that the levels of carbonyls produced in the cinnamon-flavored e-cig aerosols were much lower than that of the butter-flavored aerosols. H292 cells exposed to butter-flavored or cinnamon-flavored e-cig aerosol at the ALI under ‘sub-ohm’ conditions for 1 or 3 days displayed significant cytotoxicity, decreased tight junction integrity, increased reactive oxygen species production, and dysregulated gene expression related to biotransformation, inflammation and oxidative stress (OS). Additionally, the cinnamon-flavored e-cig aerosol induced pro-oxidant effects as evidenced by increases in 8-hydroxy-2-deoxyguanosine protein levels. Moreover, we confirmed the involvement of OS as a toxicity process for cinnamon-flavored e-cig aerosol by pre-treating the cells with N-acetyl cysteine (NAC), an antioxidant that prevented the cells from the OS-mediated damage induced by the e-cig aerosol. Conclusion The production of high levels of carbonyls may be flavor specific. Overall, inhaling e-cig aerosols produced under ‘sub-ohm’ conditions is detrimental to lung epithelial cells, potentially via mechanisms associated with OS. This information could help policymakers take the necessary steps to prevent the manufacturing of sub-ohm atomizers for e-cig devices.

Creating specialized classrooms for solar cell electric charging activities is challenging due to the lack of dedicated curriculum. No valid and reliable for assessing student’s knowledge. This study develops a four-tier diagnosis test for assessment basic knowledge of solar cell electric charging and its applications at high school. The test consisted of twenty-one items designed to assess six learning objectives. The four-tier diagnostic structure includes: the first tier evaluates content knowledge, while the third tier assesses the reasoning behind the first-tier responses using four multiple-choice options. The second and fourth tiers measure the confidence level in the first and third tiers, with response options of ‘Sure’ and ‘Not sure.’ The test was designed based on six learning objectives: (1) reading electrical specifications, (2) connecting a battery and solar cell, (3) using measurement tools, (4) applying Ohm’s Law, (5) calculating energy costs, and (6) understanding solar charging components. It was developed by four educators at Darunsikkhalai School for Innovative Learning (DSIL), all of whom hold master’s degrees. Content validity was reviewed by PhD experts in engineering and physics with 5–10 years of experience. The validation process involved 26 DSIL high school students. The result of the Index of item objective congruence (IOC) from all experts, achieving the following objective, was 1.00 for all items after rewriting with suggested corrections for the test. The test from 26 DSIL students demonstrated a Cronbach’s alpha coefficient of 0.83. The item difficulty, discrimination, and category from the diagnostic test were classified into 5 decision levels of students’ conception.

The accurate measurement of the electrical resistivity of glass at high temperatures is the foundation for the design of an electric melting furnace and electrically assisted melting. The quality of the data directly determines the reliability of large model predictions. This paper proposes a resistivity measurement method based on Ohm’s law. Through the systematic demonstration of the measurement device’s working principle and operation steps, the coupling influences mechanism of parameters such as input voltage, frequency, and sample particle size is verified. Finally, standardized test conditions with controllable errors are established. Based on high-precision measured data, this paper proposes constructing a bidirectional prediction model of “resistivity-temperature-composition”: forward prediction can derive resistivity based on glass composition, and reverse solution can optimize the glass formula design through the target resistivity.

Zero-ohm resistors, also known as jumpers, are commonly used in early radio frequency (RF) prototypes as they can help engineers identify the most optimal engineering solution for their system or create application-specific hardware configurations in products. One of the key considerations when using zero-ohm jumpers in RF circuits is the potential for signal loss and interference. Every circuit connection creates a small amount of resistance and impedance, eventually adding up over long distances or in complex circuits. This paper proposes a quantitative characterization summary of standard 0201-, 0402-, 0603-, and 0805-size surface-mount package jumpers, as well as lead-free and lead solder wires, in high-frequency applications by means of time domain reflectometry (TDR) and S-parameter measurements. The typical offset from the target 50 Ω impedance was measured to be around 3 Ω, or 5.8% relative to the measured reference value. According to S-parameter measurement results, no visible impact on attenuation was spotted up to 5 GHz compared to the reference S21 curve.