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The Office of Technology, Planning, and Integration for Observation (TPIO) maintains gap analysis tools that are used to compare both observing system attributes and the National Oceanic and Atmospheric Administration (NOAA) User Observation Requirements to help answer NOAA-wide business questions regarding observational needs and investment. Using the information connected to NOAA products, a capabilities...
An enhanced current meter was deployed in the Antarctic in March, 2017, to measure vertical heat flux in the deep ocean. The purpose of this measurement of flux is to understand how mixing of dense Weddell Sea Bottom Water becomes Antarctic Bottom Water (AABW), the densest water of the Atlantic Ocean outside of trenches. Deep mixing is one of the problems that is not yet well understood despite its...
In this study, turbulent flows were measured using the Expendable Vertical Microstructure Profiler (VMP-X) at the hydrothermal fields in the Okinawa Trough (Iheya North field and Noho site) and Sagami Bay (off Itoh and at Ohmuro Caldera) to characterize the turbulence intensity. For each observation point, the turbulent flow data were successfully measured between the sea surface and the sea floor...
The National Oceanic and Atmospheric Administration's Ecosystems and Fisheries Oceanography Coordinated Investigations biophysical mooring site 2 (M2, 56.9°N, 164°W) time series, one of the longest running time series of its kind, has provided near-continuous biophysical measurements of the southeastern Bering Sea shelf since 1995. Since then, the array has evolved into four long-term monitoring sites...
This paper proposes a voltage reference operating up to 170 °C for low-power high-temperature systems. The proposed circuit buffers body voltages to avoid degradation of temperature coefficient from nwell/psub diode leakage. For low power overhead, it measures the diode leakage and adaptively adjusts the bias current of the buffers. This enables low power consumption at low temperature, which can...
Resistive memory (ReRAM) shows promise for use as an analog synapse element in energy-efficient neural network algorithm accelerators. A particularly important application is the training of neural networks, as this is the most computationally-intensive procedure in using a neural algorithm. However, training a network with analog ReRAM synapses can significantly reduce the accuracy at the algorithm...
This paper presents the development of an energy efficient environmental sensor that sends measurement data to a cloud platform using HTTP (Hypertext Transfer Protocol) requests. The device is based on a programmable system-on-chip (PSoC), and is equipped with a temperature and relative humidity sensor for taking measurements and with a WLAN (wireless local area network) module for sending data to...
Electric vehicles (EVs) represent one of the solutions for reducing the carbon emissions worldwide. Even though EVs have recently gained more and more popularity, their adoption at a large scale is mainly prevented by several factors, such as range anxiety and battery degradation. The range of an EV is mainly limited by the energy density and specific energy of the battery, while the battery degradation...
Lithium-ion batteries are characterized by having very good performance in terms of efficiency, lifetime, and self-discharge, which allowed them to become the major player in the electric vehicle applications. However, they were not able to totally overcome the EV range anxiety. Thus, research is carried out nowadays to develop batteries with even higher gravimetric energy density, which should allow...
A highly accelerated power cycling test platform using current source converter for SiC-MOSFET power modules is proposed. The control principles of delta and average junction temperatures are introduced. By using isolated thermal fibers, the junction temperature (Tj) variations can be monitored during the test process without removal of silicone gel. The power module is tested in the conditions of...
The performance of digital circuits can be improved by more efficient implementation. For certain circuits this can be done by using pass transistor logic. This paper compares pass transistor logic styles with the standard CMOS logic style. It will be shown that pass transistor logic is able to outperform the standard approach, not only by simulation but by measurements in silicon. Measurements have...
Junction temperature is of great importance to safe operating area of IGBT modules. Various information of the IGBT operating state is reflected on electrical characteristics during turn-on transient. A unified extraction method for internal junction temperature via dynamic thermo-sensitive electrical parameters (DTSEP) during turn-on transient is proposed. Two DTSEP, turn-on delay time (tdon) and...
The paper deals with real-time estimation of the junction temperature of a SiC power MOSFET modules. The junction temperature of one device of the module is real-time estimated by measuring its current and on-state voltage at each time sample, and entering the temperature model of the device. The temperature model is obtained in a dedicated commissioning session, where the vON is measured at different...
This paper presents an experimental measurement method to obtain the transient junction temperature profile of power semiconductor devices in surge current operations. Even though a few methods to estimate the device junction temperature have been reported, they are not focused on dynamic surge conditions or experimental measurements which are important for power conversion and protection equipment...
The on-state resistance Ron of GaN devices can be affected by charge trapping as well as temperature effects. For the reliable application of the devices it is useful to distinguish between these two effects and understand the cause of power losses. In this work, three state-of-the-art GaN power transistors are investigated. An obvious Ron increase by trapping occurs in the GaN normally-off devices,...
This paper presents a demonstrator of a Lithiumion battery for automotive applications. A printed circuit board consisting of sensors, local memory elements, a digital signal processing unit and a communication interface is integrated into a Lithium-ion cell case. We demonstrate the mechanical and electrical feasibility of addressing and real-time monitoring of single Lithium-ion battery cells using...
An analysis of variation of drain current (dID/dt) of silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) in turn-on and turn-off under different temperatures has been performed in this paper. It is shown that the magnitude of turn-off dID/dt is temperature dependent and decreases with tempertature with a fixed supply voltage, load current and gate resistance. While,...
In this paper a charging kinetics of cross-linked polyethylene (XLPE) under electronic beam irradiation in scanning electron microscope (SEM) is quantified by the evaluation of trapped charge. The effect of thermal aging at different temperatures ranged from 80°C to 140°C is highlighted and analyzed. The variation of charging process of XLPE is monitored with measuring the influence current, leading...
This paper discuses on the practical example the problem of thermal modelling of power LEDs used in luminaries. The proper determination of the thermal resistance is crucial for accurate computation of the device junction temperature, which determines the device operating parameters. Here, this problem is illustrated based on the analysis of power LED heating curve measurements taken for various amount...
DC voltage measurement device is the key equipment in the DC transmission system, which is mainly used for system voltage measurement and providing voltage signals to the measuring instruments and secondary protection devices. With the rapid development of DC transmission and flexible transmission in China, DC voltage measurement device has been widely used and developed. High accuracy and high stability...
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