In this study, we numerically simulated nitrogen injection for oil reservoir development and explored the oil–gas two-phase flow model its finite difference solution method. A mathematical incorporating both gas phases was constructed, which fully considered compressibility along with Darcy's law gravitational effects in flow. The discretized using method, implicit pressure explicit saturation (IMPES) approach employed to obtain numerical solution, analyzing variation patterns of saturation,...

To screen and identify a chitosanase with high stability, we cloned the gene from Bacillus atrophaeus protease yield barren saline-alkali soil expressed this in Escherichia coli. The of B. (BA-CSN) was purified by nickel-affinity column chromatography. properties including optimal temperature, pH, substrate specificity, kinetic parameters BA-CSN were characterized. results showed that had molecular weight 31.13 kDa, temperature 55 ℃, pH 5.5, good stability at temperatures below 45 ℃ 4.0-9.0....

Silicon carbide (SiC) devices enable more compact and efficient design of applications such as traction inverters rectifiers. With miniaturization power electronics, the volume weight heatsink or cold plate occupies a significant portion. So, thermal design, especially loss evaluation, is crucial to whole system. Analytical switching model based on datasheet parameters usually adopted evaluate devices' due its convenience. However, when applied SiC metal-oxide-semiconductor...

Common source inductance is a critical issue in power electronics, especially when devices switch at high frequency. Development of SiC MOSFETs allows fast switching commutation. In order to fully utilize their ability frequency application, the impact common on loss should be explored. This paper proposes method experimentally study influence MOSFET. The calculated by measuring device junction temperature and calibrating thermal resistance from chip heatsink. ZVS soft used separate turn off...

By integrating gate drivers in the silicon carbide (SiC) power module, low parasitic inductances loop and driving are realized to improve switching performance. However, voltage variation of midpoint halfbridge module causes interference at input drivers. The is analyzed this paper, considering corresponding parameters, such as capacitance speed. A circuit model derived with experimental verification. Based on analysis, discussions done it shows that serious situations shoot-through may...

We have designed and fabricated dual spin valve heads with synthetically pinned layers. They excellent sensitivity. The read-back waveform has a small asymmetry that is also insensitive to the bias current. read gap length of 0.14 /spl mu/m write 0.2 mu/m. nominal magnetic trackwidth 0.5 0.8 were conventional inductive their pole geometry defined by focused ion beam (FIB) technology. achieved an areal read/write density as high 14.5 Gb/in/sup 2/ at data transfer rate 23/spl sim/24 MB/sec....

A High Efficiency two-stage AC/DC converter is presented and discussed in this paper, which can be applied on-board charger for electric vehicles. The front-end a high efficiency ZVS half bridge power factor correction (PFC) topology with only one device the current flowing path. Owing to voltage stress of rectifier, SiC MOSFET reduce conduction switching losses achieve frequency. downstream stage LLC resonant DC/DC converter. peak reaches 97.5%.

In bridgeless power factor correction converters and inverters, GaN high-electron-mobility transistors (HEMTs) operate in both forward reverse conduction modes, which may feature different dynamic <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> -resistance ( <italic xmlns:xlink="http://www.w3.org/1999/xlink">R</i> <sub xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> ) behaviors. Despite the extensive study of under conduction,...

We have successfully demonstrated recording at areal densities as high 14.5 Gb/in/sup 2/ data rates 195 Mbit/s (24.4 MB/s) and bit-aspect-ratios (BAR) 14, using merged inductive-write/spin-valve-read heads on low noise thin film disks. Recording a rate of 300 (37.5 has also been achieved the corresponding linear density 356 KBPI. Combining capabilities, feasibility capacity 15.6 GB per 3.5" platter rotating 5400 RPM, with average about 240 (30 MB/s), thus demonstrated,.

We have successfully demonstrated longitudinal recording at areal densities greater than 60 Gb/in/sup 2/ data rates as high 160 Mbps (20 MB/s) and a Bit-Aspect-Ratio (BAR) of 5.7, using merged inductive-write/spin-valve-read heads with microactuators on low noise thin film disks. The were fabricated standard photolithography wafer pole trimming used in currently available commercial products. At track KTPI higher, traditional servoing mechanisms are not adequate. With the use microactuator,...

We have successfully demonstrated recording at areal densities as high 36 Gb/in/sup 2/ data rates 173 Mbits/s (21.6 MB/s) and a Bit-Aspect-Ratio (BAR) of 7.3, using merged inductive-write/spin-valve-read heads on low noise thin film disks. Recording rate 590 (73.8 has also been achieved the corresponding linear density 231 KBPI. Comparisons with previous demonstrations summarized.

Abstract Rogowski coil is usually used to measure pulse current in directed energy weapon experiments, which lack of direct and low-frequency components measurement, influenced by interferences like outside electromagnetic field mechanical vibration. To acquire data with higher accuracy, a new kind fiber-optic sensor proposed achieve large working principle the introduced this paper. A fabricated cooperative agency, has measuring range from 0 200kA precision better than 1%. Comparison...

In recent years, gallium nitride (GaN) high electron mobility transistors (HEMTs) has been widely adopted in fast chargers, showcasing their potential promoting efficiency and power density. However, as level increases, especially beyond 10 kW, it becomes crucial to address not only parasitic inductances but also the thermal performance seriously. this work, a GaN integrated module (IPM) with ultra-low resistance is presented. To minimize inductances, 6-layer printed circuit board (PCB)...

In this paper, a high voltage SiC MOSFET module with series-parallel hybrid topology is presented and analyzed. The consists of two uniform parts in parallel each the part includes three sub-parts series. sub-part contains primary connected string where these has MOSFETs. These MOSFETs are divided into six sub-modules, which driven by common driving signal. A 10kV/200A fabricated based on thirty-six 1200V/40A chips. dynamic switching behavior tested analyzed at 5400V/200A speed 440ns turn-on...

Gallium nitride (GaN) high electron mobility transistors (HEMTs) are highly favored for high-power-density energy conversion systems. However, the packaging technology plays a critical role in determining device performance and reliability. The presence of parasitic inductances power loop, gate coupling between them can lead to voltage overshoot, ringing, crosstalk, additional switching losses. Additionally, thermal management GaN devices is crucial due their smaller die size. In this work,...

Sputter deposited FeRhN films with a B/sub s/ value of more than 20 kG were used as high moment flux enhancement layer in the write element order to achieve recording density 63.2 Gb/in/sup 2/. This was disposed between gap and upper portion top pole, which made Ni/sub 45/Fe/sub 55/ 16 kG. A 36 dB overwrite nonlinear transition shift less then -20 obtained at this density. finite model calculate longitudinal field gradient medium location. The results suggested significant increases both by...

A silicon carbide MOSFET half-bridge module is fabricated with 1200V devices from wolfspeed. The gate drivers and the decoupling capacitors are integrated in this module. layout of direct bonded copper (DBC) board designed to minimize stray inductance size. signal interference occurring during double pulse test (DPT) analyzed detail an analytical model. Experiments done verify model, impact discussed offer better guidance for design power Solutions also provided eliminate interference.

Abstract Near-Earth asteroids pose an enormous threat to Earth. Removing them effectively from risk orbits is a crucial issue. To improve the deflection efficiency, we propose method control intermediate asteroid as gravity tractor change orbit of potentially hazardous asteroid. A multiple kinetic impact applied its toward The goal impacts form system with First, chose that requires smaller transfer velocity increments Then, design and use multi-objective harris hawk optimization algorithm...

In this paper, a multi-pulse dynamic resistance testing method for GaN devices in different operating modes is proposed. Dynamic resistances 1 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sup> and 3 xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> quadrants of two are measured under hard-and soft-switching conditions. Results shows behaviors these devices. One the device's recovers faster quadrant than quadrant, while other quite...

The pulsed power supply provides single or repeated frequency pulse energy for the load and needs high-power switches to realize control function. For advantages of high reliability small resistance, semiconductor switch has been widely used in systems. through-flow capability is an important technical parameter switch, also basic on designing Through theoretical analysis a fast algorithm estimating was deduced by applying 10ms surge index device this paper. To prove feasibility method,...

An on-orbit thrust estimation method of satellite based on parallel system, which can achieve high-efficiency and high-precision estimation, is proposed. A complete maneuvering system framework constructed. Initially, a real-time artificial model, consistent with the actual established. The injection time control estimated optimally modification model specific treated as optimization parameter. jet time, minimum error, obtained. Then, maneuver strategy designed fed back to system. optimal...

A 3-D integrated packaging method is proposed in this letter. Redistributed layers (RDLs) are realized by integrating flexible printed circuit boards (PCBs) onto gallium nitride (GaN) high-electron-mobility transistor (HEMT) dies to enlarge the electrode area and clearance between them. GaN HEMTs with RDLs sandwiched a multilayer PCB an active metal brazing (AMB) board. Additionally, components like decoupling capacitors, gate driver, digital isolator, isolated power supply into package....

A silicon/silicon carbide (Si/SiC) hybrid switch (HyS), comprised of a high-current Si insulated gate bipolar transistor and low-current SiC metal oxide semiconductor field effect transistors, can offer high performance low cost simultaneously. As the turn-on loss account for large portion switching loss, analysis process reduction its is important improvement. This article studies how resistances signal delay regulate dynamic behavior HyS during off-to-on. It observed that be reduced...