ALBERT

Description: It has been predicted that the Moon's shadow, the cooling region, sweeping over the Earth's atmosphere with a supersonic speed could trigger bow waves since 1970. The longest total solar eclipse within next hundred years occurring on 22 July 2009 sweeps over the Eastern Asia region during the noontime period. An analysis of the Hilbert-Huang transform (HHT) is applied to study ionospheric TEC (total electron content) derived from ground-based GPS receivers in Taiwan and Japan. We not only find the feature of the predicted bow wave but also the stern wave on the equator side of the eclipse path, as well as the stern wake right behind the Moon's shadow boat. The bow and stern waves are formed by acoustic gravity waves of periods about 3 and/or 5 minutes traveling equatorward with a phase speed of about 100 m/s in the ionosphere.

Description: A new inductive photo-catalytic reactor was obtained by the alternative magnetic field and optical coupling, which was driven by AC supply. In the cylinder reactor, UV-LED lights with the wavelength of 375-380nm were evenly distributed, and the phenol solution was used as simulated wastewater. The effects of initial phenol concentration, pH, TiO 2 , H 2 O 2 , alternative magnetic frequency, current, and reaction time on the phenol degradation were investigated under an imposed alternative magnetic field. The optimized conditions and results were as follows: phenol concentrations of 15mg/L, pH of 7, H 2 O 2 of 15μL, TiO 2 of 0.18g and alternative magnetic frequency of 12 KHz and current of 2A. With these conditions, the phenol degradation ratio reached 47.1% in 1 h reaction time. The new reactor is very promising for the effective treatment of refractory organic pollutants.

Description: Pipeline integrity is significant to safe operation of long-range pipeline. To avoid critical failure of the pipeline, which may lead to great loss of property and life, MFL_PIG is often used to detect the corrosion and leakage of the pipeline. To accurately locate the defects, mileage pulses emitted by the mileage wheel are used to and emit signal to single-chip microcomputer for position. This paper investigates the factors that may affect the precision of mileage wheel, an important part of pipeline corrosion and leakage detector (MFL_PIG), investigate its working principle and present an optimized algorithm for mileage wheel to increase the precision of detection.

Description: Magnetic sensors used in Above Ground Markers (AGM) to measure the magnetic field signals are one of the main parts of AGM. By collecting the change of magnetic field parameter using magnetic sensors, AGM can record the precise time when MFL_PIG is passing by the AGM. In this paper, the magnetic sensors, such as induced coil and magneto-resistive sensor, are investigated in characteristics and performance of measurement. With advantages of low cost, high resolution and wide range of measurement, the induced coil is adopted in a novel AGM. The traction test, seal ability test and temperature test show that the AGM with induced coil as magnetic sensor works well under extreme condition and reacts to change the magnetic field with high sensibility.

Description: The mechanical properties and corrosion mechanism of both as-cast and solution-naturally age (T4) treated Mg-1.5Mn-1Ca-xSr alloys were investigated. The results showed that Sr is helpful to decrease grain size and increase the strength. The corrosion process of alloys was mainly determined by the quantity and distribution of second phases. Mg 17 Sr 2 , α-Mn and Ca-Sr phases acted as cathodes accelerated the corrosion of Mg 2 Ca anodic phase and α-Mg matrix. However, continuous distributed Mg 17 Sr 2 was beneficial to resist the happening of localized corrosion because of its barrier effect. T4 treatment could significantly improve the mechanical properties and corrosion resistance of Mg alloys because of the dissolution of Mg 2 Ca phase and the dispersive distribution of Mg 17 Sr 2 and α-Mn phases.

Description: Detection of leakage in deep geologic storage formations (e.g., carbon sequestration sites) is a challenging problem. This study investigates an easy-to-implement, frequency-domain leakage detection technology based on harmonic pulse testing (HPT). Unlike conventional constant-rate pressure interference tests, HPT stimulates a reservoir using periodic injection rates. The fundamental principle underlying HPT-based leakage detection is that leakage modifies a storage system's frequency response function, thus providing clues of system malfunction. During operations, routine HPTs can be conducted at multiple pulsing frequencies to obtain experimental frequency response functions, using which the possible time-lapse changes are examined. In this work, a set of analytical frequency response solutions is derived for predicting system responses with and without leaks for single-phase flow systems. Sensitivity studies show that HPT can effectively reveal the presence of leaks. A search procedure is then prescribed for locating the actual leaks using amplitude and phase information obtained from HPT, and the resulting optimization problem is solved using the genetic algorithm. For multiphase flows, the applicability of HPT-based leakage detection procedure is exemplified numerically using a carbon sequestration problem. Results show that the detection procedure is applicable if the average reservoir conditions in the testing zone stay relatively constant during the tests, which is a working assumption under many other interpretation methods for pressure interference tests. HPT is a cost-effective tool that only requires periodic modification of a nominal injection rate. Thus it can be incorporated into existing monitoring plans with little additional investment. This article is protected by copyright. All rights reserved.

Description: Numerical investigation was performed on the temperature control of NIF cryogenic target in order to get a temperature uniformity of 0.1mK on the surface of the capsule. Heat transfer process was discussed to find out major factors in the temperature control, tamping gas heat transfer and free convection of the tamping gas was calculated. Spherically symmetric temperature field is required due to energy released from the tritium decay within the capsule, auxiliary heating is set on the hohlraum to compensate the higher heat loss caused by the lower tamping gas thermal resistance on the mid plane. Free convection effect of the tamping gas is reduced by separating the tamping gas with plastic films and independent temperature control of the cooling arm. This research may provide theoretical foundation and reference for temperature control on the cryogenic target.

Description: In this paper, the total electron content (TEC) of the global ionosphere map (GIM) is used to detect seismoionospheric anomalies associated with the 12 January 2010 M7 Haiti earthquake, and an ionospheric model is applied to simulate the detected anomalies. The GIM temporal variation shows that the TEC over the epicenter significantly enhances on 11 January 2010, 1 day before the earthquake. The latitude-time-TEC (LTT) plots reveal three anomalies: (1) the northern crest of equatorial ionization anomaly (EIA) moves poleward, (2) the TECs at the epicenter and its conjugate increase, and (3) the TECs at two dense bands in the midlatitude ionosphere of 35°N and 60°S further enhance. The spatial analysis demonstrates that the TEC enhancement anomaly appears specifically and persistently in a small region of the northern epicenter area. The simulation well reproduces the three GIM TEC anomalies, which indicate that the dynamoelectric field of the ionospheric plasma fountain might have been perturbed by seismoelectric signals generated around the epicenter during the earthquake preparation period.

Description: In this paper, concurrent/co-located measurements of seismometers, infrasonic systems, magnetometers, HF-CW (high frequency - continuous wave) Doppler sounding systems, and GPS receivers are employed to detect disturbances triggered by seismic waves of the 11 March 2011 M9.0 Tohoku earthquake. No time delay between co-located infrasonic ( i.e. super long acoustic) waves and seismic waves indicates that the triggered acoustic and/or gravity waves in the atmosphere (or seismo-traveling atmospheric disturbances, STADs) near the Earth's surface can be immediately activated by vertical ground motions. The circle method is used to find the origin and compute the observed horizontal traveling speed of the triggered infrasonic waves. The speed of about 3.3 km/s computed from the arrival time versus the epicentral distance suggests that the infrasonic waves ( i.e. STADs) are mainly induced by the Rayleigh waves. The agreements in the travel time at various heights between the observation and theoretical calculation suggest that the STADs triggered by the vertical motion of ground surface caused by the Tohoku earthquake traveled vertically from the ground to the ionosphere with speed of the sound in the atmosphere over Taiwan.

Description: Abstract Numerical simulation of flow and transport in heterogeneous formations has long been studied, especially for uncertainty quantification and risk assessment. The high computational cost associated with running large‐scale numerical simulations in a Monte Carlo sense has motivated the development of surrogate models, which aim to capture the important input‐output relations of physics‐based models, but require only a fraction of the cost of full model runs. In this work, we formulate a conditional deep convolutional generative adversarial network (cDC‐GAN) surrogate model to learn the dynamic functional mappings in multiphase models. The cDC‐GAN belongs to a class of deep generative semi‐supervised learning methods that can be used to learn the data generation processes. Like the original GAN, a main strength of the cDC‐GAN is that it includes a self‐training scheme for improving the quality of generative modeling in a game theoretic framework, without requiring extensive statistical knowledge and assumptions on input data distributions. In particular, our cDC‐GAN model is designed to learn cross‐domain mappings between high‐dimensional input (e.g., permeability) and output (e.g., phase saturations) pairs, with the ability to incorporate conditioning information (e.g., prediction time). As a use case, we demonstrate the performance of cDC‐GAN for predicting the migration of carbon dioxide (CO2) plume in heterogeneous carbon storage reservoirs, which has both numerical and practical significance because of the safe storage requirements now mandated in many countries. Results show that cDC‐GAN achieves high accuracy in predicting the spatial and temporal evolution patterns of the injected CO2 plume, as compared to the original results obtained using a compositional reservoir simulator. The performance of cDC‐GAN models, trained using the same number of training samples, stays relatively robust when the level of spatial heterogeneity is increased. Our cDC‐GAN is pattern‐based and is not limited by the underlying physics. Thus it provides a general framework for developing surrogate models and conducting uncertainty analyses for a wide range of physics‐based models used in both groundwater and subsurface energy exploration applications.