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Hydrogen peroxide is the focus of growing attention for distributed manufacturing, reflecting its decentralized applications and shipping hazards. Two recent reports, one in Science by Wang and colleaugues and one in this issue of Joule by Surendranath, Hatton, and colleaugues, introduce innovative electrochemical methods to produce electrolyte-free aqueous solutions of hydrogen peroxide.

Welding technology is used because besides being easy to use, it can also reduce costs so it is cheaper. Especially for welding repair. From the welding repair the extent to which the strength of GMAW welds can repair components from the molded plastic mold room made of AISI 420 stainless steel. Repair of the print room components using deposit welding is tested using tensile strength and hardness as realization of resistance when holding the rate of liquid plastic entering the print room by 25 to 40 MPa, depending on the plastic viscosity, the precision of the mold and the filling level of the print room. Deposition welding method as a welding repair can affect a procedure to be able to produce a component that is safe and capable of being used in accordance with the provisions. The welding process used is reverse polarity GMAW DC with 125 A current and ER 70 S welding wire diameter 1.2 mm. Test material AISI 420. Tests carried out were tensile test, impact test and hardness test in weld metal, HAZ and base metal. From the Charpy impact test and tensile test obtained the value of welding strength which is close to the strength of the complete object, which is equal to 65%. The energy absorbed by the impact test object with GMAW welding is 5.4 Joule while for the whole test object is 8.1 Joule. The welding tensile strength is 520 MPa compared to the tensile tensile strength of 820 MPa.

Purpose The purpose of this paper is to optimize the configuration of a heat sink with phase change material for improving the cooling performance of light emitting diodes (LED). Design/methodology/approach A numerical three-dimensional time-dependent model is developed with COMSOL Multiphysics to simulate the phase change material melting process during both the charging and discharging period. Findings The model is validated with previously published works. It found a good agreement. The difference between filled cavities with phase change materials (PCM) and alternate cavities air-PCM is discussed. The last-mentioned showed a good ability for reducing the junction temperature during the melting time. Three cases of this configuration having the same total volume of PCM but a different number of cavities are compared. The case of ten fins with five PCM cavities is preferred because it permit a reduction of 21 per cent of the junction temperature with an enhancement ratio of 2:4. The performance of this case under different power input is verified. Originality/value The use of alternate air-PCM cavities of the heat sink. The use of PCM in LED to delay the peak temperature in the case of thermal shock (for example, damage of fan) An amount of energy is stored in the LED and it is evacuated to the ambient of the accommodation by the cycle of charging and discharging established (1,765 Joule stored and released each 13 min with 1 LED chip of 5 W).

We developed self-heated, suspended, and palladium-decorated silicon nanowires (Pd-SiNWs) for high-performance hydrogen (H2) gas sensing with low power consumption and high stability against diverse environmental noises. To prepare the Pd-SiNWs, SiNWs were fabricated by conventional complementary metal-oxide-semiconductor (CMOS) processes, and Pd nanoparticles were coated on the SiNWs by a physical vapor deposition method. Suspended Pd-SiNWs were simply obtained by etching buried oxide layer and Pd deposition. Joule heating of Pd-SiNW (

In this research work, experimental studies on remote start-up of Joule Heated Ceramic Melter (JHCM) used for vitrification of radioactive liquid waste (RLW) were carried out. Numerical simulations...

Alternating current electrothermal flow (ACET) induced by Joule heating is utilized to transport biologically relevant liquids in microchannels using simple electrode designs. However, Joule heating may cause significant temperature rises, which can degrade biological species, and hence, ACET may become impractical for biomicrofluidic sensors and other possible applications. In this study, the temperature rise at the electrode/electrolyte interface during ACET flow is measured using a high-resolution, noninvasive, thermoreflectance imaging method, which is generally utilized in microelectronics thermal imaging applications. The experimental findings reveal that Joule heating could result in an excessive temperature rise, exceeding 50 °C at higher voltage levels (20 V

This study evaluated energy consumption for cutting tree branches of the fig in different moisture contents (MC) levels at 10, 16, 20 and 25 % w.b., branch diameter levels at 0.5, 1, 1.5 and 2 cm, two types of cutting knives, smooth & serrated and three bevel angle of the knives at 15, 20 and 25 degrees. The analysis of results showed that cutting energy-reduced as the MC reduced. The knife bevel angle of 20 degrees at 10 % MC showed the lowest cutting energy. The lowest cutting energy was about 3.68 Joule (J) at a branch diameter of a fig about 0.5 cm at a bevel angle of 20 degrees and MC of 10 % for cutting by a serrated knife.

Controlling thermal radiation in nanoscale is critical for verifying the Planck’s law in subwavelength limit, and is the key for a range of innovative technologies including energy, display and sec...

We study parametric resonance (PR) of double-clamped micro-beams that are electro-thermally actuated by a time-dependent Joule’s heating and cooled by a steady air flow. The developed model demonstrates applicability of such device as a bifurcation-based flow velocity sensor. An AC electric current through the beam induces a time-harmonic compressive force that leads to parametric excitation of the structure. Convective cooling due to the air flow affects the location of the parametric transition curves on the driving voltage–frequency plane. The flow velocity can be obtained by measuring the frequency corresponding to the steep amplitude transition of the response. The device is modeled as an Euler–Bernoulli beam with an axial force parameterized by the electric current. The heat transfer problem is solved analytically; the heat flux due to the air flow is calculated using empirical correlations. The behavior of the beam is studied numerically, by means of finite differences, and analytically, using an approximate single degree of freedom Galerkin model, reduced to the Mathieu–Duffing equation. We show that while the PR always emerges at the driving voltage/current below the critical static buckling value, practical realization of the purely electro-thermal parametric excitation is challenging and is highly influenced by the device dimensions and quality factors. We evaluate the parameters required to assure the PR and demonstrate, using the model, feasibility of the suggested flow-sensing approach in the devices of realistic dimensions.

A calorimetric sensor has been developed for the measurement of the heat power dissipated by a superficial and localized area of the human body. In this work we present a method for the determination of the transient heat flux between the surface of the human body and the thermostat located inside the sensor. This method consists of the reconstruction of the calorimetric signal (CSRM) from the hypothesis that the power measured by the sensor is adjusted to a mathematical model consisting of a sum of exponentials of the form Wbody (t) = A0 + ∑ Ai exp (−t/τi). We show the experimental results obtained on the human body and on Joule dissipations of reference, by applying this new method (CSRM) and also the inverse filter method (IFM). The CSRM method allows to easily separate and identify the different phenomena that take place in the dissipation, from the instant the sensor is placed on the surface where the dissipation takes place, until the power reaches the steady state, and also in the instant the sensor is removed from the surface and placed back in its base. This sensor allows to obtain the power dissipated by a surface of 4 cm2 with a resolution of 10 mW. In relation to the dissipation measured in the different areas of the human body, this sensor will allow to study the possible correlations between these transient phenomena and the human physiopathology.

Alignment is very important for Kibble balances and the joule balance at the measurement uncertainty region of several parts in 108. In the joule balance, if the suspended coil is in a misalignment state, parasitic displacements including the horizontal displacements along the ${x}$ - and ${y}$ -axes and the angular displacements around the ${x}$ -, ${y}$ -, and z-axes, will be produced and introduce alignment errors during the measurement of the joule balance. It is key for the joule balance to measure these parasitic displacements of the suspended coil during the alignment stages. So this paper describes the parasitic displacements measurement method based on our laser interferometer system. By studying and discussing the decoupling methods, we can calculate the five degrees of freedom parasitic displacements without complicating the structures of the suspended coil. In addition, several uncertainty sources have been theoretically analyzed to simplify the adjustment procedure during the parasitic displacements measurement. The experimental results show that the decoupling methods are effective for the parasitic displacements of the suspended coil, and this paper can contribute to a precise alignment in the joule balance.

Since 2013, the NIM-2 joule balance apparatus has been designed and constructed at the National Institute of Metrology for the precise measurement of the Planck constant and the redefinition of the kilogram. By the end of 2016, the NIM-2 was ready for measurement in vacuum. Before the deadline of July 1, 2017, the first determination of the Planck constant obtained with the NIM-2 in vacuum was published. The measured Planck constant is 6.626 069 2(16) $\times 10^{-34}$ Js, which differs in relative terms by $-1.27 \times 10^{-7}$ from the Committee on Data of the International Council for Science (CODATA) 2014 value, with a relative standard uncertainty of $2.4 \times 10^{-7}$ . However, this result is not used for the CODATA 2017 special adjustment because its uncertainty is bigger than $6 \times 10^{-8}$ . The main uncertainty contributions are from the external field, alignment, and mass calibration. At present, the consistent research on the experiments related to the redefinition of the kilogram is still encouraged and expected by the Consultative Committee for Units. Therefore, great efforts are still put forward to improve the NIM-2 joule balance to get an uncertainty of 10−8 level. A series of improvements in progress is presented here.

Air-cored machines offer benefits in terms the elimination of magnetic attraction forces between stator and rotor. With no iron in the stator there is not a good thermal conduction path for heat generated by Joule losses in the stator winding. Results from both models and experimental tests are provided in this paper to investigate different methods of cooling air-cored windings, including natural air-cooling, direct liquid cooling, and the use of heat pipes.

Thermal-conductive models are relatively new, and have allowed the study and thermal characterization of electrical wires in overload state. Unlike the models of resistivity, or “Joule type models”, which form the basis of energy losses in wires based only on the properties of the conductors at given temperatures, the thermal-conductive models consider the behavioral characteristics of electromagnetic energy in the form stipulated by Maxwell's equations (electromagnetic model), as well as the behavioral characteristics of energy in form of heat, stipulated by the governing equations of conduction, convection and radiation. The ambient that surrounds the wire becomes very important, as well as the shape of the electromagnetic wave that is conducted in the material. Recent work has given unexpected results in the behavior of electrical conductors under states of overload. The usual models of Joule effect, were not able to predict these effects in overload, and have been used the new thermal-conductive models, with very high levels of accuracy in the predictions of global warming. Experimentally the tests have demonstrated that in overload the heat dissipation can be more than 50% higher than what is predicted by Joule type models, and theoretically, thermal-conductive models can achieve accuracy with less than 0.01% of total error (energy and temperature). But these thermal-conductive models currently require the use of a large amount of mechanical and electromagnetic equations, apart from a large amount of data (for ambient), which are highly variable, leading to the use of extensive modeling programs work for a long time for the characterization of a single wire in a particular state. In this paper we show a simplified thermal-conductive model, not only with sufficient precision for use in calculations of effective thermal dissipation, but also with sufficient simplicity, for use even in manually way.

Conductive graphene electrode of large area is required for some applications like for example photovoltaics or touch screens. Such large area graphene membrane needs specific test methods to assess defects which may obstacle its performance. In this work the infrared imaging of Joule heated graphene was proposed to estimate its uniformity and mechanical continuity. Thermal signatures of the typical mechanical defects like scratches and local resistivity inhomogeneity were identified. Distribution of the heat emission around such defects were simulated using finite elements method and then experimentally verified by recording of thermal landscape around the corresponding real graphene defects. Proposed method gives micrometric resolution and ability to inspection of large area electrodes depending on applied optics. Presented results give suggestions how graphene imperfections generate observed hot points related to graphene layer defects.

Quality of resistance spot-welded joints depends on Joule’s heat generation and, in turn, a current profile, dynamic resistance change, and its initial value. In the present work, the impact of electrode force and dome radius of hemispherical electrodes on initial resistance between electrodes was investigated. Two combinations of workpieces of zirconium alloy thickness of 0.25 + 0.25 mm and austenitic stainless steel thickness of 0.3 + 0.3 mm were used. The experimental results obtained were compared with calculated values using published equations and data on physical properties of these materials. After that, the possibility of stabilization resistance between electrodes by preheating current pulses was studied. The pulses had different algorithms of current rise: discrete and stepwise, as well as sharp and smooth with longer upslope. The results show impossibility of reliable prediction and absolute stabilization of initial values of resistance between electrodes. No clear relationship between these values and electrode force has been found. An increase in dome radius of hemispherical electrodes reduces mean resistance values for zirconium alloy but has no effect for stainless steel. Also, it does not affect dispersion of values for both materials. The rate of preheating current rise has no appreciable effect on stabilization of resistance between electrodes in all cases. Stepwise current rise significantly reduces dispersion of resistance values for zirconium alloy but has no effect for stainless steel. However, their dispersion significantly decreases after preheating in comparison with initial values.

We propose a new system for the fundamental units, which includes and goes beyond the present redefinition of the SI, by choosing also $c=\hbar=1$. By fixing $c=c_\circ $m/s = 1, $\hbar=\hbar_\circ $ Js = 1 and $\underline{\mu_\circ}=\mu_\circ $N/A$^2$ = 1, it allows us to define the metre, the joule, and the ampere as equal to (1/299 792 458) s, $(1/\hbar_\circ = .948 ... \times \ 10^{34})\ {\rm s}^{-1}$ and $\sqrt{\mu_\circ \rm N}= \sqrt{\mu_\circ c_\circ / \hbar_\circ}\ {\rm s}^{-1}= 1.890...\times 10^{18}\ {\rm s}^{-1}$. It presents at the same time the advantages and elegance of a system with $\hbar = c = \underline{\mu_\circ} = \underline{\epsilon_\circ } = k = N_A = 1\,$, where the vacuum magnetic permeability, electric permittivity, and impedance are all equal to 1. All units are rescaled from the natural ones and proportional to the s, s$^{-1}$, s$^{-2}$, ... or just 1, as for the coulomb, ohm and weber, now dimensionless. The coulomb is equal to $\sqrt{\mu_\circ c_\circ / \hbar_\circ}= 1.890... \times 10^{18}$, and the elementary charge to $e=1.602...\times 10^{-19} {\rm C} = \sqrt{4\pi\alpha}=.3028... $ . The ohm is equal to $1/\mu_\circ c_\circ$ so that the impedance of the vacuum is $Z_\circ = 376.730... \Omega =1$. The volt is $ 1/ \sqrt{{\mu_\circ c_\circ \hbar_\circ}}\ {\rm s}^{-1} = 5.017... \times\ 10^{15}\ {\rm s}^{-1}$, and the tesla $c_\circ $V/m = $ \sqrt{{c_\circ^3}/{\mu_\circ\hbar_\circ}}\ {\rm s}^{-2} = 4.509... \times 10^{32}\ {\rm s}^{-2}$. The weber is $ 1/ \sqrt{{\mu_\circ c_\circ \hbar_\circ}} = 5.017... \times\ 10^{15}$. $\ K_J =483\,597. \ $... GHz/V $= e/\pi = $ .09639..., and $R_K = 25\,812.\ ...\ \Omega =1/2\alpha\simeq 68.518$. One can also fix $e$ = 1.602 176 634 $\times 10^{-19}$ C, at the price of adjusting the coulomb and all electrical units with $\mu_\circ=4\pi\times 10^{-7}\eta^2$ where $\eta^2, \propto \alpha$, is very close to 1., Comment: 26 pages, 2 tables

We propose a new concept on theoretical explanation of the relationship between transient non-bonded interaction and thermo-mechanical behavior on rubber-like materials. The theoretical equation can describe the extension ratio dependence of stress and temperature simultaneously. The approach found important evidence on the presence of the uncertainty relation between non-bonded interaction and angular momentum of molecular chain. We applied this concept to analysis for thermal molecular motion of Joule's experiments on thermo-dynamic properties of the vulcanized rubber. Our theoretical approaches, at least, provide the important parameters; the number of non-bonded interaction, the fluctuation energy, the attractive energy, the radius of rotation, the finite extensibility effect and the effective molar mass. These parameters can be used as a rule of thumb guide for multi-physics design in the future work to bridge the atomic behavior and the thermo-mechanical behavior which is associated with various rubber properties such as energy loss, damping, flexibility, friction, heat build-up, fatigue and fracture.

This paper deals with analyzing losses of three-phase high current and low voltage inverter, which is intended for automotive applications. High current inverters are becoming more popular in automotive area due to increasing the number of high power electrical drives in cars and trucks. The less reliable and less efficient, usually mechanical drive systems are replaced for more effective and more reliable electrical drive systems. There are liquid pumps, HVAC blowers, turbochargers, etc. Total losses of the common inverters are divided into three main parts, conductive and joule losses, switching losses and additional losses. The highest part of losses usually generates power switches, in this case MOSFETs. The size of other part of losses is determined by parameters of used components, i.e. DC-link capacitors, shunt resistor sensors, etc. The power losses and efficiency of inverter are analyzed by using the simulation model in LTspice. The model of inverter contains spice models of MOSEFTs and DC-link capacitors. The parasitic components of high current and excitation traces are also included into model. The analyzed inverter contains only DC-link shunt resistor for current sensing purpose in order to minimize joule losses of shunt resistors. Joule losses of shunt resistor, DC-link capacitor losses, reverse polarity battery protection MOSFET and three-phase half-bridge inverter are analyzed from power losses and efficiency point of view. The final result of this paper describes the size of losses of power circuit and the value of efficiency of inverter, which the high current inverter is able to reach.

This was a case report which described the background, method, and test results of the effect of 3 wavelength lasers transmeatal irradiation treatment on motion sickness, using combined lasers with an output of 2.5 mW @ 532 nm 10.0 mW @ 808 nm 2.0 mW @ 1064 nm for transmeatal irradiation treatment. 10 patients aged 50 ± 25 were treated with MWLLLTI at a dose of 104 Joule in total for both ears per day for 15 consecutive days. It was found that MWLLLTI stimulation was effective in motion sickness treatment.

By the end of 2018, the 26th Congress of Metrology and Weights (Conférence Générale des Poids et Mesures, CGPM) had been held. A new definition of mass unit has been approved on the meeting of CGPM. Mise en pratique-kg includes the guide of dissemination after the redefinition of kilogram. The traditional dissemination of mass unit is carried out in air. The new method for dissemination from Planck constant to primary mass standard or from primary mass standard to secondary mass is implemented under vacuum. The dissemination method after the redefinition of mass unit will be changed from Planck constant to primary mass standard or from primary mass standard to secondary mass standard. The measurement of weights under vacuum will replace the measurement of weights in air. To transfer weights from vacuum vessel to vacuum mass comparator, a vacuum transfer equipment (VTE) is developed by National Institute of Metrology, China (NIM). A multistage manipulator system is designed to transfer weight under vacuum between VTE and vacuum mass comparator or Joule Balance. The experimental results show that the performance of VTE is efficient for transferring the weights under vacuum.

If we wish to sustain our terrestrial ecosphere as we know it, then reducing the concentration of atmospheric CO2 is of critical importance. An ideal pathway for achieving this would be the use of sunlight to recycle CO2, in combination with water, into hydrocarbon fuels compatible with our current energy infrastructure. However, while the concept is intriguing such a technology has not been viable due to the vanishingly small CO2-to-fuel photoconversion efficiencies achieved. Herein we report a photocatalyst, reduced blue-titania sensitized with bimetallic Cu–Pt nanoparticles that generates a substantial amount of both methane and ethane by CO2 photoreduction under artificial sunlight (AM1.5): over a 6 h period 3.0 mmol g−1 methane and 0.15 mmol g−1 ethane are obtained (on an area normalized basis 0.244 mol m−2 methane and 0.012 mol m−2 ethane), while no H2 nor CO is detected. This activity (6 h) translates into a sustained Joule (sunlight) to Joule (fuel) photoconversion efficiency of 1%, with an apparent quantum efficiency of φ = 86%. The time-dependent photoconversion efficiency over 0.5 h intervals yields a maximum value of 3.3% (φ = 92%). Isotopic tracer experiments confirm the hydrocarbon products originate from CO2 and water.

The study of software energy consumption is gaining more importance due to the wildly increasing use of resource limited portable devices that run on batteries, in addition to the economical and environmental concerns. Mobile hardware has been mostly well optimized on their energy consumption, but that cannot be said for mobile applications. Studying the energy consumption of applications requires investigating the amount of energy consumed at a granule level (e.g., method calls), and therefore, identifying the leaks which are responsible for peaks in energy consumed by an application. In this paper, we performed an empirical measurement of energy consumption for 10 Android applications using a software-based tool called PETRA. We reported and compared the energy consumed by method calls by the test cases. The study reveals that there are clear variations on the average energy consumption in the studied applications and are ranging from 0.25 Joule/second to 1.25 Joule/second. Moreover, the study revealed that the relative high average energy consumption in is associated with some frequently called methods by the test cases. These methods are identified and reported as energy hotspots. These findings could help practitioners to minimize the energy pattern by applying refactoring techniques during software maintenance.

Applied to the production of windings, the PCB technology is promising for developing high performance slotless permanent magnet machines, since it makes possible to envisage winding shapes and topologies difficult or impossible to achieve by the classical wire technology. However, compared to wire windings, PCB windings are more subject to eddy current losses because of their high width-thickness ratio. To counteract these eddy currents, the conventional solution consists in reducing the track width but in conjunction with an increased number of turns. That requires, in order to keep the supply voltage constant, to consider parallel connections of conductive tracks at the winding terminals. This paper tackles the eddy current problem differently by adding some slits distributed along the conductive tracks. This amounts to carry out local parallelizations without impacting the motor supply voltage. This study, through a parametric analysis of different slitting possibilities in wave windings, shows that reconnect parallel sub-tracks at one end-winding of two delivers nearly the same results than a classical full parallelization but with a potential simplification of the interconnections between the PCB tracks constituting the winding. Furthermore, it shows that this conclusion is independent of the winding shape considered.

Topological magnetic charge Q is a fundamental parameter that describes the magnetic domains and determines their intriguing electromagnetic properties. The ability to switch Q in a controlled way by electrical methods allows for flexible manipulation of electromagnetic behavior in future spintronic devices. Here we report the room-temperature current-controlled topological magnetic transformations between Q = -1 skyrmions and Q = 0 stripes or type-II bubbles in a kagome crystal Fe$_3$Sn$_2$. We show that the reproducible and reversible skyrmion-bubble and skyrmion-stripe transformations can be achieved by tuning the density of nanosecond pulsed current of the order of ~10$^{10}$ A$^{-2}$. Further numerical simulations suggest that spin-transfer torque combined with Joule thermal heating effects determine the current-induced topological magnetic transformations.

This study presents a lamp-pumped Nd:glass laser system capable of achieving joule level output energy at 1-Hz repetition rate with high beam quality. The 1.8 J of energy in a 5 ns pulse was achieved with 1.5 mJ injected energy. The laser system includes a beam shaping module and an eight-pass, lamp-pumped amplifier. The laser amplifier demonstrated long-term energy stability of 1.76% PV and 0.29% RMS when operating at 1.8 J for 30 minutes. In a longer period of operation, no damage or obvious beam degradation was found. A uniform gain distribution with a single-pass small-signal gain of 3.89 was acquired with the four-lamp-pumping method, and thermally induced wavefront aberration was mitigated. Finally, a high beam quality was obtained using a homemade optically addressed liquid crystal light valve. After compensation, the near-field modulation decreased from 1.38 to 1.21, meanwhile, the beam contrast decreased from 6.54 to 4.71%. In terms of the far-field quality, a 90% far-field energy concentration was 2.5 times the diffraction limit.

Coaxial wet-spinning is used to fabricate stretchable liquid metal sheath-core microfibers with consistently high conductance., Highly conductive and stretchy fibers are crucial components for smart fabrics and wearable electronics. However, most of the existing fiber conductors are strain sensitive with deteriorated conductance upon stretching, and thus, a compromised strategy via introducing merely geometric distortion of conductive path is often used for stable conductance. Here, we report a coaxial wet-spinning process for continuously fabricating intrinsically stretchable, highly conductive yet conductance-stable, liquid metal sheath-core microfibers. The microfiber can be stretched up to 1170%, and upon fully activating the conductive path, a very high conductivity of 4.35 × 104 S/m and resistance change of only 4% at 200% strain are realized, arising from both stretch-induced channel opening and stretching out of tortuous serpentine conductive path of the percolating liquid metal network. Moreover, the microfibers can be easily woven into an everyday glove or fabric, acting as excellent joule heaters, electrothermochromic displays, and self-powered wearable sensors to monitor human activities.

Radiographic imaging is an omnipresent tool in basic research and applications in industry, material science and medical diagnostics. Often, the information contained in more than one modality can be valuable, but difficult to access simultaneously. This talk reviews developments in laser-plasma-accelerators for protons, electrons and x-rays from solid and gas targets for multimodal imaging. Laser-driven ion acceleration and x-ray generation have been investigated using tungsten micro-needle-targets at the Texas Petawatt laser [1]. The experiments and supporting numerical simulations reveal peaked proton spectra around 10 MeV with significant particle count and a strong keV level x-ray source. The source size for both has been measured to be in the few-µm range. Both sources were eventually applied to simultaneous radiographic imaging of biological and technological samples. In recent experiments at BELLA Center’s high repetition rate 100 TW dual-arm laser, steps were taken towards bi-modal x-ray and electron imaging of dynamic events such as hydrodynamic shocks, in which often both density and electro-magnetic fields are important quantities to measure. Here, a shock was driven by a 1 Joule, 200 ps laser focused in a 30 µm wide water jet. A laser wakefield accelerator was driven by a second 2 Joule, 40 fs laser in a gas-jet target, providing both 150 MeV electrons and broadband betatron x-rays up to ˜10 keV for projection imaging. This research aims to leverage unique properties readily available in laser plasma accelerators for applications. Specifically, the emission of pulsed, bright, multimodal bursts of radiation can open new ways in biological imaging (e.g., with ns-synchronized ions and x-rays) and in high-resolution diagnostics for high-energy density science (e.g., with fs-synchronized electrons and x-rays). [1] T. M. Ostermayr et al., “Laser-driven x-ray and proton micro-source and application to simultaneous single-shot bi-modal radiographic imaging,” Nat. Commun., vol. 11, no. 1, pp. 1–9, Dec. 2020. This work was supported by the DFG via the Cluster of Excellence Munich-Centre for Advanced Photonics (MAP) and Transregio SFB TR18. This work has been carried out within the framework of the EUROfusion Consortium and has received funding, through the ToIFE, from the European Union’s Horizon 2020 research and innovation program under grant agreement number 633053. The authors acknowledge funding by the Air Force Office of Scientific Research (AFOSR)(FA9550-14-1-0045, FA9550-17-1-0264). Work supported by DOE FES under grant DE-SC0020237. Work supported by US DOE NNSA DNN R&D, by Sc. HEP, by the Exascale Computing Project and by FES LaserNetUS under DOE Contract DE-AC02-05CH11231.

The article presents the stress impedance investigation of CoFeNiMoBSi alloy in variation of the applied magnetic field. In order to carry out the study, a specialized stand was developed that allows for loading the sample with stresses and simultaneous action of the DC (direct current) magnetizing field. The tests were carried out for as-cast and Joule annealed samples. The significant influence of the magnetizing field acting on the sample on the stress-impedance results was demonstrated and the dependence of the maximum impedance change in the stress-impedance effect was determined, depending on the field acting. The obtained results are important due to the potential use of the stress-impedance effect for the construction of stress sensors.

Joule heats which are generated by coals in an applied electric field are directly correlated with variation resistivity of electrical parameters of coals. Moreover, the joule heating effect is closely related with microstructural changes and relevant products of coal surface. In the present study, a self-developed applied direct current (DC) field was applied onto an experimental system of coals to investigate variation resistivity of electrical parameters of highly, moderately and lowly metamorphic coal samples. Moreover, breakdown voltages and breakdown field intensities of above three coal samples with different metamorphic grades were tested and calculated. Variation resistivity of electrical parameters of these three coal samples in 2 kV and 4 kV DC fields were analyzed. Results show that internal current of all coal samples increases continuously and tends to be stable gradually after reaching the “inflection point” at peak. The relationship between temperature rise effect on anthracite coal surface in an applied DC field and electrical parameters was discussed. The temperature rise process on anthracite coal surface is composed of three stages, namely, slowly warming, rapid warming and slow cooling to stabilize. The temperature rise effect on anthracite coal surface lags behind changes of currents which run through coal samples. There’s uneven temperature distribution on anthracite coal surface, which is attributed to the heterogeneity of coal samples. In the experiment, the highest temperature on anthracite coal surface 65.8 ℃ is far belower than the lowest temperature for pyrolysis-induced gas production of coals 200 ℃. This study lays foundations to study microstructural changes and relevant products on coal surface in an applied DC field.

Recently in Joule, Qin and co-workers determined the glass transition temperatures (Tg) of Y6 and its six close variations to infer relative stabilities and established a structure-Tg framework. They further proposed the key guidelines to stabilize the microstructure and performance in both binary and ternary solar cells.

Micro-supercapacitors are attracting increasing attention due to their potential applications in multiple real-world energy scenarios such as wearable electronic devices, powering the internet of things, and medical applications. While tremendous efforts are being made in the performance enhancement, one of the bottleneck issues inhibiting their upscaling is the complicated manufacturing process. In this issue of Joule, Bruce Dunn and colleagues demonstrated a fully processable micro-supercapacitor engaging a photopatternable hydroxide ion conducting solid electrolyte, which is thermally and dimensionally stable with a high conductivity of 10 mS cm−1.The micro-supercapacitor composites of VN and NiCo2O4 electrodes and the [AMIM][OH]/SU-8 hydroxide-conducting solid electrolyte show high areal capacitance of 250 mF cm−2 at 20 mV s−1 sweep rate, which is one of the highest performances among reported results.

Anodic aluminum oxide (AAO) film with a thickness ranging from 20 to100 μm was prepared by using a large-sized Al plate (4 cm × 10 cm) to investigate the anodization parameter effect on the film thickness and volume expansion factor. A corrosion treatment (voltage = 0 V) was performed to investigate the film dissolution caused by acid. The actual anode surface temperature was also measured to confirm the field-assisted nature of AAO dissolution. The film thickness increases exponentially with temperature, and increases approximately linearly with voltage, duration or concentration. The volume expansion factor gives a first rising and then falling trend with temperature or duration, while it has a nearly linear trend with voltage or concentration. The volume expansion factor increases with the intensified electric field, while its decrease is attributed to the Joule heat-enhanced dissolution. In the case of large film thickness (> 20 μm), the pore confinement effect may be one of the reasons for the change of volume expansion factor. In addition to the conventional parameters, the heat transfer-related parameters such as sample size also greatly affect the AAO film growth.

The membrane distillation (MD)-based desalination process is thought to be a promising strategy to address global challenges, such as safe water-energy crisis and environmental pollution. Here, we demonstrate a novel self-heated vacuum (MD) system employing a graphene–PVDF flat sheet membrane Joule heater that enables the combination of the interfacial heating of a feed stream and conventional VMD for energy efficient sea water desalination. In this system, the direct delivery of low voltage DC power to a superhydrophobic graphene–PVDF flat sheet membrane Joule heater was placed in a filtration module, and effectively heats the feed stream directly at the feed/membrane interface. Thus, it eliminates the preheating of feed solution and temperature polarization (TP), along with enhanced permeate flux, which in turn significantly reduces the energy requirement for the desalination process. The graphene–PVDF flat sheet membrane Joule heater was obtained via simple phase inversion technique, and exhibited excellent Joule heating performance, superhydrophobicity, and graphene laminar stacking-induced high porosity. While treating a saline feed without preheating, and with optimum membrane and experimental variables, our self-heated MD system achieved a permeate flux of 23.44 L m−2 h−1 and salt rejection of 99.41%, with the lowest specific heating energy (Qsh) consumption of 0.109 kW h L−1 and the highest gain output ratio (GOR) of 5.72, respectively. This is the greatest performance achieved so far, compared to the performance of solar heating (photothermal) and induction heating-based self-heated MD systems reported previously. The optimum membrane surface temperature (T* = 38 °C) and effective membrane area (71.1%) were assessed using FVM simulation, and were validated by the corresponding experimental results. This energy efficient self-heated vacuum MD system is suitable for high purity water production and effective sea water desalination. Furthermore, by harvesting the electrical energy required for membrane Joule heating from renewable energy (solar energy) and using feed streams with low grade waste heat, we could further increase the economic viability and application potential of the system. The self-heated vacuum MD system demonstrated here constitutes an effective approach for a sustainable, decentralized water desalination technology.

Pumped thermal electricity storage is a thermo-mechanical energy storage technology that has emerged as a promising option for large-scale (grid) storage because of its lack of geographical restrictions and relatively low capital costs. This paper focuses on a 10 MW Joule-Brayton pumped thermal electricity storage system with liquid thermal stores and performs detailed conventional and advanced exergy analyses of this system. Results of the conventional exergy analysis on the recuperated system indicate that the expander during discharge is associated with the maximum exergy destruction rate (13%). The advanced exergy analysis further reveals that, amongst the system components studied, the cold heat exchanger during discharge is associated with the highest share (95%) of the avoidable exergy destruction rate, while during charge the same component is associated with the highest share (64%) of the endogenous exergy destruction rate. Thus, the cold heat exchanger offers the largest potential for improvement in the overall system exergetic efficiency. A quantitative analysis of the overall system performance improvement potential of the recuperated system demonstrates that increasing the isentropic efficiency of the compressor and turbine from 85% to 95% significantly increases the modified overall exergetic efficiency from 37% to 57%. Similarly, by increasing the effectiveness and decreasing the pressure loss factor of all heat exchangers, from 0.90 to 0.98 and from 2.5% to 0.5% respectively, the modified overall exergetic efficiency increases from 34% to 54%. The results of exergy analyses provide novel insight into the innovation, research and development of pumped thermal electricity storage technology.

We investigate hot carrier propagation across graphene using an electrical nonlocal injection/detection method. The device consists of a monolayer graphene flake contacted by multiple metal leads. Using two remote leads for electrical heating, we generate a carrier temperature gradient that results in a measurable thermoelectric voltage VNL across the remaining (detector) leads. Due to the nonlocal character of the measurement, VNL is exclusively due to the Seebeck effect. Remarkably, a departure from the ordinary relationship between Joule power P and VNL, VNL ∼ P, becomes readily apparent at low temperatures, representing a fingerprint of hot-carrier dominated thermoelectricity. By studying VNL as a function of bias, we directly determine the carrier temperature and the characteristic cooling length for hot-carrier propagation, which are key parameters for a variety of new applications that rely on hot-carrier transport., We acknowledge the support from the European Research Council (ERC Grant Agreement No. 308023 SPINBOUND), the Spanish Ministry of Economy and Competitiveness, MINECO (under contracts MAT2013-46785-P and Severo Ochoa Program SEV-2013-0295), and the Secretariat for Universities and Research, Knowledge Department of Generalitat de Catalunya. J.F.S. acknowledges support from the Juan de la Cierva (JCI-2012-12661) and the Beatriu de Pinós programs, and M. V. C. from the Ramón y Cajal program (RYC-2011-08319).

Although the Victorian sciences of evolution and energy physics are now inextricably bound in modern ecology, it took some time for these sciences to sit comfortably together. This chapter briefly explores the historical connection between energy concepts and ecology, as well as some of the problems, limitations and potential attached to their common usage, especially as nineteenth century thinking about energy intersects with Darwinian biology. Among other things, William Thomson’s famous calculation predicted a probable lifespan for the sun that was far too short to allow for evolutionary processes as Darwin described them. Darwin himself increasingly discussed “energy,” though he eschewed its emergent scientific sense and implied, among other things, that energy can be created. In spite of these manifest differences, however, several Victorian physicists argued for the biological and ecological implications of energy science—notably Ludwig Boltzmann and James Prescott Joule. Physicists and biologists sought to find a language of nature that decentered the human, and both struggled with, and contributed to, a worldview that still dogs our attempts to foster more ecological ways of being and reading.

We demonstrate the highest efficiency ($\sim$80%) second harmonic generation (SHG) of Joule level, 27 femtosecond, high contrast pulses in a type-I lithium triborate (LBO) crystal. In comparison, potassium dihydrogen phosphate (KDP) gives a maximum efficiency of 26%. LBO thus offers high intensity ($>$10$^{19}$ W/cm$^{2}$), ultra-high contrast femtosecond pulses, which have great potential for high energy density science particularly with nanostructured targets as well as technological applications., 5 pages, 3 figures, 2 tables

International audience; James Prescott Joule's (1818-1889) bicentenary took place in 2018 and commemorated by the IDTC with a Symposium-'James Joule's Bicentenary: Scientific and Pedagogical Issues Concerning Energy Conservation'-at the European Society for the History of Science (ESHS and BSHS), 14th-17th September, 2018, in London. This symposium had three main objectives: It aimed specifically to celebrate James Joule's achievements considering the most recent historiographical works with a particular focus on the principle of conservation of energy; It served the purpose of discussing the scientific and pedagogical issues related to heat, energy and work and how they are presented in textbooks and worked out in classrooms; It also provided discussions on the present situation of teaching and learning science through the use of History of Science, both in K-12 and college level with an emphasis on energy and related concepts. In the following, the Introduction of this Special Issue on Joule is presented.

In this chapter, we report our latest work on the technical development of the cryogenically cooled Yb:YAG-ceramics laser as scalable technology toward achievement of repetitive kilo-joule-class lasers. In our first trial, we obtain a high small signal gain of 20.4 with a high stored energy of 149.0 J using a conductively side-cooled Yb:YAG ceramic multi-disk laser amplifier operating at 100-K cooling temperature. In the second trial, we obtain 117-J nanosecond pulsed laser output with a cryogenic-helium-gas face-cooled Yb:YAG ceramic multi-disk laser amplifier. In this study, we obtain 42.3% energy-extraction efficiency from the energy stored in the Yb:YAG ceramic disks. We also determined the specifications of the face-cooled laser amplifier designed for repetitive operation by flowing helium gas on the end faces of the Yb:YAG ceramic disks. The feasibility of a practical design for kilo-joule-class diode pumped solid state lasers with a cryogenically cooled Yb:YAG ceramic disks was demonstrated by the developed high-gain and high-efficiency laser technologies.

Graphene nanoplatelet (GNP) doped epoxy/polycaprolactone (PCL) blends have been proposed in the present work. It has been observed that the addition of GNPs induces an enhancement on the electrical conductivity with a prevalent exponential behavior due to the hopping conduction. In this regard, the presence of small insulating domains of PCL leads to an increase of the electrical conductivity due to the reduction of agglomerates. Furthermore, the addition of GNPs allows the thermal heating by Joule's Effect, leading to an autonomous self-healing due to the melting of the PCL. In this context, several samples where subjected to Joule's activated healing, leading to healing efficiencies from 40 to 70% under the presence of an artificial crack. Therefore, the proposed novel materials open a way for autonomous self-healable systems. S0266353821003067

We report on the recent development of a thin-disk laser system providing 720-mJ, sub-picosecond pulses at 1030 nm. The CPA system is operating at 1 kHz and was specially designed for applications in laser-based lightning rod.

This article presents a postfault control algorithm that minimizes the stator Joule losses in multiphase induction machines under an open-phase fault and for different star connection layouts. The key novelty is that the algorithm can be applied to any configuration of a multi- n -phase machine, independently of the connection of the neutral points. The latter is analytically derived and is based on the space vector representation of the machine model. In addition, it is shown that a low number of neutral points helps to reduce the winding losses in case of an open-phase fault but requires additional control regulators and computational efforts. The theory is applied to an asymmetrical quadruple-three-phase induction machine, which is configured to represent five different motor layouts. Finally, experimental results are presented to validate the control algorithm. The optimal solution that is given in this article can be employed for the control of symmetrical or asymmetrical multiphase machines with different star connection layouts and in any open-phase postfault operation.