Derived Quantities Uncertainty Propagation in High Precision Battery Testing

The experimental verification of a Lithium-ion battery for automotive life requirements utilizes significant laboratory resources and calendar time. If the amount of life testing required to validate a cell design for automotive applications can be reduced, new cell designs could be confidently implemented at lower cost and in shorter time. High precision coulometry (HPC) has recently emerged as a promising candidate for shortening the time required for validating cell life. Literature examples have demonstrated improved identification of the mechanisms causing capacity fade1 and qualitative sorting of higher performing cells2. Academic groups have pioneered this approach but have been primarily limited to testing low currents that are used to probe the rates of side reactions in calendar life scenarios. Our research focus has been the design, development and validation of a 200 A, high precision (<50 ppm current and <25 ppm voltage) battery tester in partnership with Arbin Instruments and Sandia National Laboratory, with the support of the US Department of Energy (DOE) Advanced Research Projects Agency- Energy (ARPA-E)3. The capability to perform high precision measurements at currents up to 200 A means the additional degradation brought about by high-rate cycling can be evaluated in addition to calendar assessments. Additionally, we aim to quantitatively assess performance degradation trends by linking presently measured values to future performance. Validation testing is presented using 5 Ah prismatic cells to quantify the reduction in test time that is practically achievable using high precision measurements. Continuous cycle aging using multiple current profiles and ambient temperatures is conducted with periodic reference performance tests. The mathematical relations between capacity, resistance, coulombic efficiency, and electrode endpoint slippage are leveraged to define various life prediction methods. The reference performance test measurements from both the high precision tester and standard commercial reference tester are entered as inputs into the life prediction models. Improved measurement precision can result in reduced uncertainty bands when extrapolating life metric trends into the latter stages of cell life. Enhanced measurement precision can also enable the quantification of long term trends at earlier stages of testing.

This paper introduces the wireless sensor network technology, explores a new method for explosion shock wave test, expounds the hardware and the key technology of wireless sensor network node. By out field test It shows that the node has the advantages of convenient installation, safe and reliable, high test precision, can implement the real-time acquisits transmiss and evaluats pressure signal. The design effectively solve the bottleneck of wave field test.

The conversion efficiency of heat to electricity is the basic parameter of thermoelectric element, thermoelectric unicouple and thermoelectric devices. In principle, the heat to electricity conversion efficiency of thermoelectric element has been defined as the electrical output power of the element divided by its thermal input power. Due to the heat loss by convection and radiation heat transfer the test result of the heat to electricity conversion efficiency has a large errors. The authors present a test method for heat to electricity conversion efficiency of thermoelectric unicouple. The thermal input power of thermoelectric unicouple has been divided into the electrical output power plus thermal output power out of the cold end of the unicouple. The later has been determined by a thermoelectric thermal power meter. The method avoids the difficulties to measure the input thermal power into the hot side of the unicouple, so that the convection and radiation heat lose out of the unicouple side can be ignored. Owing to Seebeck Coefficient of the thermoelectric semiconductor materials could be many times of the metals, the thermoelectric thermal power meter has high sensitivity, so that high test precision could be gained in test for conversion efficiency of thermoelectric unicouple. The paper presents some test results for heat to electricity conversion efficiency of thermoelectric unicouple, and discusses about the factors which affect the test results.

The measure of the friction factor in the location of the event is very important to get accurate inputs to model the accident, as the friction factor depends on environmental conditions and the dynamics of the event. In some low-middle income countries, accident reconstruction experts, usually don't have the feasibility to acquire expensive equipment as high precision accelerometers; therefore, it is important to identify a low-cost method that provides data quality comparable with high precision equipment. This study presents a comparison of three methods: VC4000PC accelerometer, sensor kinetics mobile app and video analysis by tracker (free software). The methods have been compared experimentally for emergency braking with blocked wheel, as well as using ABS. Data from the three methods were recorded simultaneously. Data analysis was made applying inferential statistics. The results indicate that the data collected with the smartphone app ensure good accuracy and does not provide significant variance in comparison with the accelerometer. On the other hand, the data obtained by video analysis shows a good linear relationship with the accelerometer; however, it shows some statistical evidence of differences related to precision and variances in comparison with accelerometer device. The confidence interval, absolute error, and other estimators have been obtained for the smartphone method, to promote the optimal using by the experts to get parameters on site and apply to a traffic accident reconstruction.

To improve the efficiency and precision of missile servo mechanism testing, as the research object, a certain missile servo mechanism was studied in this paper. Based on PC/104 bus and virtual instrument technique, a missile servo mechanism automatic test system was presented, and the design and development on hardware and software of the system was described in detail. The system, which is featured with its simple operation, high precision, high reliability, scalable and portable test software, has been proved to be feasible by the test result.

To ensure the performance of the optical system, the machining accuracy of lens with long focal lengths is required to ensure the image quality. A new method for lens transmission wavefront power spectral density (PSD) in mid-frequency domain measurement using binary phase computer-generated hologram (CGH) is presented. This technique is widely applicable and is particularly useful for measuring large-size lenses with long focal lengths. A comparison experiment of the CGH measurement with results from a Fizeau sphere interferometry method is carried out to verify the accuracy and convenience of the measurement. Furthermore, measurement uncertainty due to CGH fabrication process is analysed. Analysis of the CGH test showed the overall accuracy of less than 1 nm RMS for a sphere lens with over 30 m focal length and Φ410 mm clear aperture. CGH can provide reference spheres with high precision, in the meantime greatly shorten air space, thus reducing the effect of vibration and air turbulence, therefore is of great importance for lens transmission wavefront PSD measurement. The realization of high precision, high efficiency and nondestructive testing of long focal-lens wavefront PSD ensure the ultra-precision and certainty level of machining, hence improving the comprehensive performance of the optical system.

To measure the energy efficiency performance and the characteristics of electronic cooling fans a high-precision suction side test rig was designed according to the corresponding national DIN and international ISO standards. To evaluate the influence of the test rig design on the precision of the performance measurements of the fan, the complete test rig designs were analyzed in detail with the commercial CFD solver Star-CCM+ from Siemens PLM Software. Since at the test rig the pressure values of the fan are measured indirectly at the test rig chamber and not at the fan itself, the pressure values from the simulation as read out at the test rig chamber and at the fan itself were compared to deliver the required precision of the test rig design. Furthermore, the effect of the baffle plate and the throttle characteristics on the energy efficiency performance measurements of fans for electronic cooling have been analyzed.

The quadriwave lateral shearing interferometry (QWLSI) based on double birefringent crystals of beam displacer (DBCs-BD), which can generate the lateral shearing interference wavefront of four beams of overlapped replicas in the DBCs-BD orthogonal directions. When the replica waves of overlapped incident to the analyzer, and it’s the direction of transmission axis is set as 45° or 135°, the QWLSI’s polarization interferogram can be obtained. This paper deduced the principle of QWLSI in detail, and showed the phase retrieval by the Fourier analysis of the QWLSI’s interferogram, then the wavefront can be reconstructed by using the differential Zernike polynomial fitting. In our investigation, the correction range of PBD’s orthogonal angle error is within –0.5° ~ 0.5°, the maximum error in PV: 0.0012λ and the maximum error in RMS: 1.3789×10-4λ in wavefront reconstruction. Moreover, when the testing light tilts to incident on the PBD in the range of –0.4° ~ 0.4°, by correcting the shear distance be used for wavefront reconstruction to achieve high-precision wavefront testing result. Finally, the experiment shows that the DBCs-BD-QWLSI exhibits feasibility, and high precision.

The machining accuracy of optical aspheric surface can reach nanometre, but micro/nanometre measurement is the bottleneck for us to improve the accuracy. Aiming at various influential factors during the high-precision aspheric surface testing, the building up of three-dimensional nanometre motion platform is the key technology. The movement of high precision linear motor on the motion platform is controlled by computer. Then the motors drive the laser sensor to the position (X, Y, Z) on the aspheric surface which is needed to inspect. Then the position is inspecting by the sensor built in the platform. Through data processing and analyzing, the result of analysing and evaluation of the aspheric surface are got. At last, this measurement system can provide data for compensation processing to the numerical machine tools to improve the profile accuracy of the aspheric surface.

Quadriwave lateral shearing interferometry (QWLSI) is based on double birefringent crystals of a beam displacer (DBCs-BD), which can generate the lateral shearing interference wavefront of four beams of overlapped replicas in the DBCs-BD orthogonal directions. When the replica waves are overlapped incident to the analyzer and the direction of the transmission axis is set as 45° or 135°, the QWLSI's polarization interferogram can be obtained. This paper deduces the principle of QWLSI based on the DBCs-BD and presents the analysis of orthogonal error influence based on the DBCs-BD and the phase retrieval error of QWLSI when shear displacement by tilted incident on the DBCs-BD. In our investigation, we have established the correction range of the PBD's orthogonal angle error is within -0.5∘-0.5∘, the maximum error in PV is 0.0012λ, and the maximum error in RMS is 1.3789×10-4 λ in wavefront reconstruction. Moreover, when the testing light tilts to incident on the PBD in the range of -0.4∘-0.4∘, correction of the shear distance is used for wavefront reconstruction to achieve a high-precision wavefront testing result. Finally, the experiment shows that QWLSI based on the DBCs-BD exhibits feasibility and high precision.

It is known that the cosmological constant can be dynamically tuned to an arbitrary small value in classes of scalar tensor theories. The trouble with such schemes is that effective gravity itself vanishes. We explore the possibility of avoiding this “no-go” with a spatially varying effective gravity. We demonstrate this in principle with the non-minimally coupled scalar field having an additional coupling to a fermionic field. The expectation value of the scalar field gets anchored to a non-trivial value inside compact domains. But for the non-minimal coupling to the scalar curvature, these configurations are analogous to the non-topological solutions suggested by Lee and Wick. With non-minimal coupling, this leads to a peculiar spatial variation of effective gravity. As before, one can dynamically have the long distance (global) gravitational constant G and Λ, the cosmological constant, tending to zero. However, inside compact domains, G can be held to a universal (non-vanishing) value. Long distance gravitational effects turn out to be indistinguishable from those expected of general theory of relativity (GTR). There are two ways in which the ensuing theory may lead to a viable effective gravity theory: a) the compact domains could be of microscopic (sub-nuclear) size, or b) the domains could be large enough to accommodate structures as large as a typical galaxy. Aspects of effective gravity and cosmology that follow are described. A toy Freidman-Robertson-Walker (FRW) model free from several standard model pathologies and characteristic features emerges. Although this proposed model remained less studied but became an important aspect in initiating a viable approach in addressing the cosmological constant problem. Comparison with some additional observational constraints like quantitative constraints on gravitational constant. G, from some high precision tests will be included our forthcoming paper which will address the limitations of the present paper.

The Bremen drop tower at the Center of Applied Space Technology and Microgravity (ZARM) provides high quality micro-g condition needed for many high precision tests. This is even more improved by the development of a free flyer technology. This new technology is used for a free fall test of the MICROSCOPE differential accelerometers which only can work with a residual acceleration disturbance level below 25 nano-g in the high resolution mode. The French MICROSCOPE space mission for testing the Weak Equivalence Principle is scheduled for 2012/2013. The free fall accelerometer test campaign at ZARM is an important part of the pre-mission test program. In this article the new free flyer technology, its performance as well as the accelerometer tests are described.

With the epidemic raging around the world, people's health is under great threat. How people can detect the epidemic in the first time becomes a very important matter. At this stage, the primary symptom of the outbreak is fever. Therefore, whether in hospitals, various government administrative departments or in office buildings, residential areas and other crowded areas, will be measured by the body temperature to judge the health of personnel. However, the traditional methods of temperature detection need to touch or test the subjects at close range, which will bring certain threats to the human health of the inspectors. Therefore, the design of non-contact and remote epidemic prevention and control equipment is extremely urgent. In this paper, through the use of STM32F103C8T6 micro-controller, the ultrasonic ranging module is used to monitor the distance of the measured personnel in real time. When the measured personnel enter the test range, the infrared temperature sensor MLX90614 is used to test the temperature of the measured personnel. Once it exceeds the set alarm value, the alarm is alerted. The system has high testing efficiency and precision, which is suitable for epidemic prevention and control.

The paper presents a novel approach for uncertainty propagation in multicomponent two-phase displacements. This approach originates from and extends the frozen streamlines (FROST) distribution method for two-phase Buckley–Leverett displacements described in Ibrahima et al. (Transp Porous Media 109(1):81–107, 2015). The developed FROST method for multicomponent systems relies on the analytical solutions of gas–oil displacements provided by the theory of gas injection processes. With examples considering a stochastic porosity field in 1-D, we apply the developed framework to uncertainty propagation in three- and four-component systems to obtain the probability distribution of different compositions in space and time and verify that the results are in excellent agreement with the reference analytical Monte Carlo simulations.

Determination of echinococcosis IgG antibodies using magnetic bead-based chemiluminescence immunoassay