Joule Energy Research Articles

Effect of the plasma self-radiation on the growth of thermal filamentation instabilities in imploding Z pinches

The development of thermal filamentation (TF) instabilities in a current-carrying plasma shell under the action of the plasma self-radiation was analyzed in terms of a small perturbation theory. A stationary collisional radiative model was used to calculate the parameters of the bremsstrahlung, recombination radiation, and spectral line radiation. It has been shown that radiative losses can either enhance or weaken the growth of TF instabilities. The pattern of the effect is governed by the dependence of the energy lost by the plasma due to radiation, Q Rad, on the plasma temperature T. If Q Rad increases slower than ∼T, the radiative losses enhance TF instabilities. In the opposite case, that is when Q Rad increases faster than ∼T, the radiative losses lead to suppression of TF instabilities. When the energy lost due to radiation is greater than the Joule energy input, TF instabilities can be completely stabilized due to radiation. The plasma parameter ranges for which stabilization of TF instabilities may occur due to radiation have been found for aluminum and argon.

Revisiting neutron yield in table-top nuclear fusion driven by an intense femtosecond laser pulse interaction with the gas clusters

With the development of femtosecond (fs) laser technology, an fs laser pulse with 10s of Joule, even 100s of Joule energy is available and the focused laser intensity can be expected to induce the pure Coulomb explosion of the cluster with a much larger average radius than before. Meanwhile, the production of gas cluster with an average radius of upto 10s of nanometer has been possible. In this case, it is necessary to reinvestigate the feasibility of 109 n/shot neutron yield for the practical application in the intense fs laser-driven nuclear fusion. In this work, the neutron yield from the explosions of the D2 clusters of 6–20 nm average radius at the 0.5–100 J pulse energy and the CD4 clusters was investigated theoretically. It is found that the optimum neutron yield of 109 n/shot can be obtained at the laser energy and the cluster radius currently available. However, a clustered-gas jet with a large cross-section is demanded to match the proper plasma diameter.

Portable air-fed cold atmospheric plasma device for postsurgical cancer treatment.

Surgery represents the major option for treating most solid tumors. Despite continuous improvements in surgical techniques, cancer recurrence after surgical resection remains the most common cause of treatment failure. Here, we report cold atmospheric plasma (CAP)–mediated postsurgical cancer treatment, using a portable air-fed CAP (aCAP) device. The aCAP device we developed uses the local ambient air as the source gas to generate cold plasma discharge with only joule energy level electrical input, thus providing a device that is simple and highly tunable for a wide range of biomedical applications. We demonstrate that local aCAP treatment on residual tumor cells at the surgical cavities effectively induces cancer immunogenic cell death in situ and evokes strong T cell–mediated immune responses to combat the residual tumor cells. In both 4T1 breast tumor and B16F10 melanoma models, aCAP treatment after incomplete tumor resection contributes to inhibiting tumor growth and prolonging survival.

Biomechanical analysis of long pass in U-19 women football players

Kicking movement is process of moving position on leg. Biomechanical analysis explains kick performance which influenced by kinematics and kinetics factors. The research purpose analyzed biomechanical long pass movement. This research is both qualitative and quantitative. The research sample are 11 Indonesian woman football players who were taken by saturated sampling. Data in the form of long pass kick video with airborne ball test. Data analyzing used Kinovea software to determine the flexion angle of backswing kick leg, hip angle, and distance to target, then looking for the force, power, and energy in kick motion. The motion analysis shown that sample 3 produces closest distance to target as far as 0.65 m which done with flexion angle of backswing knee is 740 and hip angle of 640. The force exerted by sample 3 is 10.09 N, resulting in a ball speed of 22.42 m/s and a kinetic energy of 113.12 Joule, potential energy of 14.64 Joule and mechanical energy of 127.76 Joule. It can be concluded that accuracy of long pass kick are influenced by flexion angle of backswing kick knee, hip angle, power and force as well as producing energy in the form of kinetic, potential, and mechanical energy.

What are the differences in protective characteristics of orthodontic mouthguards? An in vitro study.

SummaryBackgroundOrthodontic patients wearing fixed appliances are susceptible to traumatic dental injuries during contact-sport. This laboratory study investigated the protective qualities of orthodontic mouthguards using impact-testing to a typodont fitted with a fixed appliance through peak load transfer and retention of the mouthguard.MethodsSeven orthodontic mouthguards [three custom-made (Medium-CM, Heavy-CM, Heavy-pro-CM); three commercially-available mouth-formed (Shock-Doctor® Ultra Braces, Opro® Ortho-Gold Braces, Opro® Ortho-Bronze Braces) and a Shock-Doctor® Instant-Fit] were fitted to a maxillary arch typodont bonded with a fixed appliance and impact-tested using 0.5 or 1 Joule (J) energy via hockey-ball, cricket-ball or steel-ball projectile. A load-cell recorded peak load transfer through mouthguard to typodont with retention scored in a binary manner dependent upon any displacement following impact. Differences across mouthguards were calculated with ANOVA or Kruskal–Wallis test for normal and non-normal data, respectively. Post hoc comparisons across mouthguards were conducted via Dunnett's test with Sidak correction.ResultsOnly the three custom-made and Opro® Ortho-Gold Braces were not displaced by impact-testing. For these, Opro® Ortho-Gold Braces transferred the smallest load for 3/6 impact-tests, followed by Medium-CM. Heavy-pro-CM performed poorly, ranking penultimate or worst for all impact-tests. Significant differences were found between mouthguards for cricket-ball and steel-ball set-ups. The Opro® Ortho-Gold Braces performed better than the Heavy and Heavy-pro-CM for 0.5 J cricket-ball impact-test (P < 0.05), whilst Medium-CM performed better than Heavy-pro-CM. For 1 J cricket-ball, there were significant differences between Medium-CM and Heavy-pro-CM (P < 0.05). For 0.5 J steel-ball, the Medium-CM performed significantly better than both Heavy-pro-CM and Opro® Ortho-Gold Braces (P < 0.05), whilst Heavy-CM performed better than the Heavy-pro-CM (P < 0.05). For the 1 J steel-ball, Medium and Heavy-CM performed better than Opro® Ortho-Gold Braces (P < 0.05).ConclusionsOpro® Ortho-Gold and Medium-CM mouthguards offer the best protection for low-impact sports, whilst Medium or Heavy-CM mouthguards are recommended for high-impact sport.

Engineering multilayered MXene/electrospun poly(lactic acid) membrane with increscent electromagnetic interference (EMI) shielding for integrated Joule heating and energy generating

Proliferous bloom of wearable electronics arouses higher demands on electromagnetic pollution defense and multifunctional trait. Yet the EMI shielding materials capable of versatility still remains a challenge. Herein, the multilayered MXene/PLA composite membrane was designed with increscent EMI shielding by alternately assembling MXene onto electrospun poly(lactic acid) (PLA) nanofiber mats. Attributing to the intact conduction of MXene layer and the multiple-reflection-absorption effect, the multilayered membrane achieved an optimum shielding efficiency (SE) of 55.4 dB. The predominant conductivity of MXene rendered the multilayered membrane remarkable Joule heating performance with a rapid temperature response from 31 °C to 52.8 °C within 25s at a low trigger voltage of 1.5 V. The triboelectric nanogenerator (TENG) based on the multilayered membrane exhibited outstanding energy generation with a peak power density of 457.1 mW/m2. This work provides a feasible pathway to prepare high-performance bio-based EMI shielding membranes and gives insights into the design of highly integrated multifunctional devices.

Fault Current Limiting Operations of Three-Phase Transformer Type SFCL Using Two Common Connection Points Between Secondary Windings

Three-phase transformer type superconducting fault current limiter (SFCL) using two common connection points between secondary windings, which consisted of three-phase transformer windings wound on three legs of E-I iron core and two/three superconducting modules (SCMs), were suggested and its fault current limiting operations according to ground-fault types were analyzed. To verify the effective operation of the three-phase transformer type SFCL using two common connection points between secondary windings, the unsymmetrical ground and the symmetrical ground faults were applied into three-phase power simulated system with the suggested SFCL. For the comparison, the ground faults were generated into three-phase transformer type SFCL with two/three SCMs. Through analysis on the test results, the SFCL with two SCMs was confirmed to have no different fault current limiting operation from the SFCL with three SCMs. The structure of E-I iron core with three magnetically coupled legs and the constitution of three secondary windings with two common connection points were analyzed to be contributed to the same fault current limiting operation. Furthermore, the power consumption and the joule energy of the SCMs comprising both the SFCL with two SCMs and the SFCL with three SCMs during the fault period had shown to be almost the same except for the transient period due to the quench time difference in case of the single-line ground fault.

Slag uses in making an ecofriendly and sustainable concrete: A review

A single ton of ordinary Portland cement (OPC) demands around 4.0 G Joule energy and creates about a ton of CO2 emission. As part of our effort to preserve the environment, the incorporation of ground granulated blast-furnace slag (GGBFS) or fully replaced by alkali-activated slag (AAS) as an alternative binder to OPC. This concrete is environmental-friendly and also eases concerns in energy usage, raw material, and manufacturing cost for the traditional concrete. The cementitious properties of GGBFS and AAS promote their usage in the concrete matrix. Partial inclusion of slag for cement produces OPC or fully replaced by AAS is getting more attention as it is more pumpable, chemically stable, and resistant to an aggressive environment. This paper reviews the source, clean production and chemical compositions of the GGBFS and AAS. This literature review also objects to provide reviews on the properties, hardening conditions, and behaviors of GGBFS and AAS -based concrete composites as well as to synopsize the research development trends to generate comprehensive insights into the potential applications of GGBFS and AAS concrete as raw building materials for making sustainable and greener concrete composites, towards industrializing ecofriendly buildings today.

Temperature of metal wires for nanosecond and microsecond electrical explosions in vacuum

Experiments show an inverse correlation between temperature and heating time for the electrical explosion of thin metal wires in vacuum. Faster heating of the wire results in higher energy release in a short time, while slow heating lasts longer but releases less energy before breakdown. Breakdown is a natural barrier to the direct release of Joule energy and an increase in the metal temperature to an abnormally high value. An increase in the current rate from 0.07 to 170 A/ns leads to a decrease in the heating time from 5 μs to 5 ns and an increase in the wire temperature from 450 K to 4000 K before the voltage breakdown. This inverse correlation between the heating time and the temperature of the wire in a vacuum can be explained by the inertia of evaporation of the hydrocarbon impurity from the surface of the hot metal.

Implosion dynamics and radiation characteristics of preconditioned hybrid X-pinch driven by double pulse current

Preconditioned hybrid X-pinch (HXP) experiments have been performed on the Qin-1 facility to investigate the effect of the prepulse current on the implosion dynamics and radiation characteristics. HXPs with molybdenum wires of ∼1.2 mm in length and 25 to 50 μm in diameter have been tested. Driven by the prepulse current, the molybdenum wire is heated to a core-corona structure with a Joule energy deposition of 0.5–4.8 eV/atom, which is smaller than its atomization enthalpy. The radial expansion velocity of the wire core is 0.5–3 km/s. The main current of 450 kA/400 ns is applied ∼610 ns after the prepulse current. The implosion dynamics of the preconditioned HXP is characterized by two-shell structure implosion. Immediately after the main current starts, the current mainly passes through the corona plasma located in a large radius, and the implosion of corona plasma lasts for ∼100 ns until the corona plasma collides with the wire core. Then, the current distribution switches from the corona plasma to the wire core, which results in the onset of implosion of the wire core. The implosion of the wire core generates hot spots and x-ray radiation. The calculated inductance and radius of the current sheath agree with the experimental results. The corona plasma performs as a current switch, which allows the main current passing through the wire core after 100 ns. It indirectly contributes to sharpening the main current used for implosion of the wire core. A single hot spot with x-rays over 2.5 keV is measured using the preconditioned HXP.

Low-velocity impact response of pre-stressed glass fiber/nanotube filled epoxy composite tubes

The aim of this study is to investigate the low velocity impact behavior of pre-stressed glass fiber/epoxy (GRP) nanocomposite tubes. During the production of filament wound tubes with a winding angle of ±55°, carbon nanotubes (CNT) were introduced to the epoxy resin at 0.5%wt and 1.0%wt by ultrasonic method. The nanocomposite tubes were pre-stressed to 32 bars internal pressure, one of the specified operating pressures according to ANSI/AWWA C950 standards. Low velocity impact tests were performed on the pure and CNT added pre-stressed GRP tubes at 5, 10 and 15 Joule energy levels. As a result of the experiments, the contact force-time, force-displacement graphs and absorbed energy values by the samples were obtained. In addition, the damage zones on the specimens were investigated. The effects of CNT reinforcements on the impact response and damage mechanisms of the specimens were evaluated. By adding CNT, it was observed that the damage areas of the samples decreased and was found to affect the impact response of nanocomposite tubes.

Features of the thermal stabilization theory of composite superconductors: The nonlinear description of the dissipative states

The features of the Joule's energy dissipation in a composite high-temperature superconductor with a power equation of the voltage-current characteristic cooled by liquid helium or hydrogen are discussed. It is shown that the non-standard thermal stabilization conditions of composite superconductors can exist if the nonlinear temperature dependences of the electrical resistivity of the stabilizing matrix and heat flux to liquid refrigerant are considered. First, there may be no minimum currents of the existence and propagation of a normal zone. Second, the intensive cooling of a composite superconductor by liquid refrigerant significantly increases the range of the stable currents, which leads to the existence of the supercritical applied currents. Third, an increase in the temperature of a composite superconductor may occur under the conditions close to adiabatic during irreversible propagation of the thermal instability despite its intensive cooling by liquid refrigerant. This effect must be considered when determining the burnout conditions of a composite superconductor. The performed numerical experiments are compared with the results obtained from the existing thermal stabilization theory of the composite superconductors, which is based on the linear temperature dependence of the critical current density of superconductor and jump-like transition from the superconducting state to the normal.

Optimized Design of Sub-kilo Joule Dense Plasma Focus and Measurement of Neutron Yield

This paper specifically talks about optimized design strategy of sub-kilo Joule Dense plasma focus (PF) fusion device in a full-fledged systematic manner. Recently, there are many pulsed power groups working in design and development of various PF devices in the range of sub-kilo joule energy. Few of them are publishing with the optimized operating parameters for the maximum neutron yield. Most of them, talks about the estimation of PF parameters based on traditional high voltage break down mechanisms in vacuum, plasma pinch behavior and neutron generation, which are optimized for higher energy level (few kJ to MJ) PF devices. It has been very tricky and iterative way to achieve maximum neutron yield for a sub kJ PF device. A conceptual design strategy is presented for estimation of four critical PF tube parameters. These four parameters are: Anode radius, cathode radius, effective anode length and insulator length. This is very important to know these parameters, in advance of actual fabrication and plasma pinch experiments. A 400 J PF device is designed and operated at 20 kV with the help of above design strategy in single go. Maximum neutron yield is measured 50% higher with wide range of deuterium gas pressure (6–12 mbar) among sub kJ PF devices. A detailed design strategy, experimental pulsed power system development, neutron measurement and results are discussed.

Field coupling-induced synchronization via a capacitor and inductor

Resistor-based voltage coupling is often used to realize complete synchronization between identical nonlinear circuits while phase synchronization is investigated between non-identical nonlinear circuits (periodic or chaotic oscillation). Indeed, the coupling resistor used to consume certain Joule heat and energy before reaching the synchronization target when continuous current passed across the coupling device. In this paper, capacitor and inductor is paralleled with one coupling resistor, respectively, and the coupling devices are used bridge connection between two LC hyperchaotic circuits for investigating synchronization problems. As a result, the coupling channel can be activated to propagate energy and balance the outputs voltage from the two circuits. The dimensionless dynamical equations are obtained by applying scale transformation on the circuit equations when field coupling is switched on. It is found that the threshold of coupling intensity for reaching synchronization and the power consumption of controller can be decreased when the coupling resistor is paralleled with on capacitor or inductor. The mechanism could be that involvement of coupling capacitor(or inductor) can trigger time-varying electric field (or magnetic field), and the energy flow of field coupling via coupling capacitor (or inductor) can contribute the exchange of energy in the coupled nonlinear circuits. It can give insights to investigate synchronization on chaotic systems, neural circuits and neural networks including synapse coupling and field coupling. Finally, the experimental results on circuits are also supplied for further verification.

Interferometric measurements of static and dynamic dipole polarizability of titanium atoms using fast electrical explosion of fine metal wires in vacuum

The rapid electrical explosion of fine metal wires in vacuum generates gas cylinders of metal atoms surrounded by low-density and fast-expanding plasma corona. For fully vaporized wires, we utilize the integrated-phase technique, based on laser interferometry, to measure the dynamic dipole polarizability of metal atoms. Titanium wire with a diameter of 20 μm and a length of 1 cm was rapidly vaporized by a fast-rising current at ∼10 ns. We find that the dynamic dipole polarizability of titanium atoms equals 20.5 ± 2 Å3 for 532 nm and 10.6 ± 1 Å3 for 1064 nm. The wire reaches a totally vaporized state when the expansion velocity in a vacuum is ∼5.5 km/s. To vaporize Ti wire, the deposited Joule energy exceeded tabulated enthalpy of atomization by ∼2.8 times. Two-wavelength diagnostic allows reconstruction of the static dipole polarizability 9.13 ± 1.7 Å3 and electron transition energy 3.13 ± 0.2 eV with the corresponding transition wavelength of 396.6 ± 26 nm. This reconstructed wavelength matches to the group of strong dipole-allowed atomic spectral lines for Ti between 394.87 and 402.46 nm for ground-state transitions 3d24s2.

Emergy-based economic and environmental analysis and multi-objective optimization of a two-cascade solar gas turbine power plant

One of the critical issues in the design and optimization of the power generation systems are the economic and environmental characteristics of these systems. Accordingly, in this paper, the new multi-step Emergo-Exergo-Economic and Emergo-Exergo-Environmental approach has been selected to examine the economic and environmental aspects and optimization of a new two-step solar-powered gas turbine cycle. In the first step, the power generation system is analyzed based on the first and second thermodynamic rules. And the corresponding exergy and energy parameters are determined at different points in the power cycle. In the next step, the weight and the price of all components are determined. And the amounts of emergy related to different equipment and mass flows (based on the conversion of the exergy unit to the solar energy joule (sej)) are calculated, and the monetary and ecological performance of the cycle are examined. Based on the governed results, the two most irreversible equipment with maximum exergy destruction and minimum emergy-based exergoenvironmental factor are selected for retrofit. Based on the sensitivity analysis, the effect of decision variables on the exergy and emergy parameters has been investigated. To achieve an optimum design, the multi-objective optimizations have been performed to maximize the exergetic efficiency, monetary and ecological performance using the particle swarm optimization algorithm. The Optimization results show that the exergetic, monetary and ecological performance of the cycle can be improved significantly with change in decision variables.

Control of hydrogen peroxide production in plasma activated water by utilizing nitrification

In this study, ammonia (NH3) vapor was added to an atmospheric pressure argon plasma jet generated by a sinusoidal power supply (with an applied voltage of 4 kV and frequency of 35 kHz) and it was analyzed by electrical, optical, and chemical probe measurements. A total gas flow rate of 1200 sccm under 2% flow rate of either water or ammonia solution at concentrations up to 0.75% mixed with 98% argon feeding gas. The dissipated power of the plasma jet estimated by voltage-charge plots was found to decrease continuously with increase in ammonia concentrations at a fixed applied voltage. The optical emission spectra inside the quartz tube obtained for the NH3 mixed plasma indicated the presence of nitrogen emission lines which were absent in the water only mixed argon plasma. Colorimetric measurements of hydrogen peroxide (H2O2) and nitrite () in plasma activated water (PAW) were performed at different consumed energy varied by plasma exposure time. The H2O2 concentration decreased to 4 ppm from 14 ppm, while the concentration simultaneously increased to 6 ppm from 1 ppm as the ammonia concentrations increased to 0.75% from 0% throughout 2.07 × 103 joule energy consumption. We also analyzed the corresponding variation of pH values, in absence of ammonia, PAW leads to acidification but addition of small amount of ammonia in plasma is sufficient to make it alkaline. Additionally, we measured the hydroxyl (OH) radical density in gas and liquid phases by utilizing UV absorption spectroscopy and chemical probe method, respectively. OH radical density in both phases also decreased with the increase in the NH3 concentrations. Experimental results obtained from this experiment can be attributed to control H2O2 concentrations in the PAW via plasma-assisted nitrification.

Minimally Invasive Laser Treatment of Ureterocele.

Introduction: Ureterocelemay cause severe pyelo-ureteral obstruction with afebrile urinary tract infections in infants and children. Early decompressive treatment is advocated to reduce the risk of related renal and urinary tract damage. Endoscopic techniques of incision have been offered utilizing diathermic electrode. We adopted laser energy to release the obstruction of the ureterocele and reduce the need of further surgery. Our technique is described and results are presented, compared with a group of matched patients treated by diathermic energy.Materials and methods: Decompression was performed by endoscopic multiple punctures at the basis of the ureterocele. Holmium YAG Laser was utilized with 0.5–0.8 joule energy, through 8–9.8F cystoscope under general anesthesia. The control group received ureterocele incision by diathermic energy through pediatric resettoscope. Foley indwelling catheter was removed after 18–24 h. Renal ultrasound was performed at 1, 3, 6, and 12 months follow-up. Voiding cysto-urethrogram and radionuclide renal scan were done at 6–18 months in selected cases. Statistical analysis was utilized for data evaluation.Results: From January 2012 to December 2017, 64 endoscopic procedures were performed: 49 were ectopic and 15 orthotopicureteroceles. Fifty-three were in duplex systems, mostly ectopic. Mean age at endoscopy was 6.3 months (1–168). Immediate decompression of the ureterocele was obtained, but in five cases (8%) a second endoscopic puncture was necessary at 6–18 months follow-up for recurrent dilatation. Urinary tract infections and de novo refluxes occurred in 23.4 and 29.7% in the study group, compared to 38.5 and 61.5% in the 26 controls (p < 0.05). Further surgery was required in 12 patients (18%) at 1–5 years follow-up (10 in ectopic ureteroceles with duplex systems): seven ureteral reimplantation for reflux, five laparoscopic hemy-nephro-ureterectomy. Orthotopic ureteroceceles had better outcome. Secondary surgery was necessary in 13 patients (50.0%) of control group (p < 0.05).Conclusions: Early endoscopic decompression should be considered first line treatment of obstructing ureterocele in infants and children. Multiple punctures at the basis of the ureterocele, performed by low laser energy, is resulted a really minimally invasive treatment, providing immediate decompression of the upper urinary tract, and reducing the risk of further aggressive surgery.

Application of let‐through energy to back‐up over‐current protection on high‐voltage feeders

Let-through energy (LTE) refers to the I 2 t or Joule energy that a conductor is exposed to during a fault on the feeder. This energy is influenced by the magnitude of the fault current and time it takes for the protection system to clear the fault. If the LTE exceeds the conductor thermal energy limit, the conductor will get damaged. This concept of LTE evaluation is applied to the inverse definite minimum time (IDMT) current based back-up protection elements on a multisource high-voltage feeder in a hypothetical and actual network. Another method to calculate the relay operating time for IDMT relays was developed based on an average disk speed of electromechanical over-current relay and the proportionality of its speed to the magnitude of the fault current. This method was incorporated into a software application to generate results. These results allow the user to evaluate the conductor LTE exposure, total fault time exposure, the effect of instantaneous fault clearing and the application of auto-reclose cycles. An energy-area evaluation was applied to quantify and evaluate small protection settings changes. The conclusion is that LTE analysis on back-up protection should be considered for high-voltage feeders to ensure that the conductors are protected.

Pulsed Heating of Carbides

Experimental studies of carbides are briefly reviewed. The high-temperature properties of carbides used in nuclear power and aerospace engineering are considered. Temperature is measured from either plane surface emittance or the emittance of thin samples prepared in the form of a melting blackbody model. The following quantities are measured: Joule energy, heat capacity (predominantly Сp), electrical resistance, and phase-transition heat versus temperature (up to 5000 K). The pre-melting heat capacity exceeds the equilibrium value, but temperatures measured at the characteristic points of the phase diagram correspond to the design diagram.