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Using Shallow Electromagnetic And Magnetic Techniques To Map Soil Texture And Characterize Salinity And Water Dynamics Below Pecan Orchards, El Paso County, Texas, Kristina Sasser

Open Access Theses & Dissertations

Non-invasive, near surface geophysical tools provide a time efficient and cost-effective approach to study the shallow subsurface. Electromagnetic induction (EMI) instruments are a category of these near surface methods that provide spatial and temporal information (2-D to 4-D) about shallow (<6 m) subsurface properties, from which soil salinity, clay content, and water content can be estimated. However, deconstructing soil apparent electrical conductivity (ECa) from EMI methods into its component parts remains a challenge. This research uses EMI and magnetic geophysical techniques to: (1) compare and contrast the distribution and behavior of ECa, both spatially and temporally, at two flood irrigated agricultural sites (pecan orchards) with different soil layers, properties, and controls on electrical conductivities that lie within the same floodplain in far west Texas; and (2) develop a one-dimensional inversion model using ECa and soil texture data at specified layers from established sites of known high and low ECa to determine soil layer resistivities at various dates during the irrigation season. Data are compared to soil sensor bulk EC and volumetric water content data at corresponding depths to validate results. Soils at both sites exhibit large ECa contributions from textural controls, and irrigation frequency. The combination of these two controls dictate where and how quickly secondary minerals precipitate, clog soil pores, reduce infiltration, and salinize the groundwater. Insight from this research aids in ongoing efforts to characterize vadose zone hydrology in dryland critical zones with high infiltration and serves as a guide for locations where future soil sampling will occur.

Emerging From Content And Language Integrated Learning And English-Medium Instruction, Is Clil-Ised Emi The Next Trend Of Education?, Hengzhi Hu

Higher Learning Research Communications

Objectives: The text aims to present a comparison of Content and Language Integrated Learning (CLIL) and English-Medium Instruction (EMI), followed by a discussion of CLIL-ised EMI, a new educational phenomenon, regarding its feasibility in content-based bilingual programmes.

Method: The ideas presented in this paper are principally drawn from previous research and literature about CLIL and EMI, as well as from my personal experience with content-based bilingual education programmes.

Results: Although CLIL and EMI differ in nature, CLIL-ised EMI supplements traditional EMI, which has a single objective of content learning, with special attention to students’ needs, particularly their …

Near Field Scanning-Based Emi Radiation Root Cause Analysis In An Ssd, Xiangrui Su, Wenchang Huang, Junghee Cho, Joonki Paek, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

In Modern Portable Electronic Devices, Solid-State Drives (SSDs) Are Commonly Used and Have Been Identified as One of the Dominant Electromagnetic Interference (EMI) Noise Sources that Can Cause RF Desensitization Issues. in This Paper, the EM Emission Source from an SSD Module is Identified and Analyzed using Near Field Scanning and Dipole Moment Source Reconstruction. the Identified Noise Current Path Including the Power Management Integrated Circuit and the Decoupling Capacitor is Validated with the Assistance of Full-Wave Simulation. the Measured Noise Voltage is Used as an Excitation in the Simulation and the Simulated Near Fields Showed a Good Correlation with …

A Novel Broadband Double-Ring Holed Element Metasurface Absorber To Suppress Emi From Pcb Heatsinks, Bülent Urul, Habi̇b Doğan, İbrahi̇m Bahadir Başyi̇ği̇t, Abdullah Genç

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a new Broadband Double Ring Hole Element (BDHE) meta-surface absorber is studied to suppress EMI from PCB heatsink for 1-12 GHz covering L, S, C, and X bands. The proposed metamaterial-structure consists of resistances and 8 ring resonators, four of which are inner and four are outer that are configured to provide an absorbing effect. For broadband, numerical simulations show that an average of 65% absorption value is obtained between 4-12 GHz. It is determined that this value reached 69.84% by increasing the used resistance values (R = 150?). This value may be significant to reduce the …

Analysis And Optimization Of The Two-Phase Series Capacitor Buck Dc-Dc Converter, Salahaldein Ali Aboajila Ahmed

Graduate Theses and Dissertations

Current sharing schemes for conventional multi-phase converters are based on sensing each phase current to deliver the current information to their controllers. In conventional buck converters, this fact may require a preset current sharing ratio at the expense of efficiency, which eventually requires a larger sensing circuit to achieve the sensing accuracy of each phase. Introducing the concept of automatic current sharing is one of the solutions to tackle this issue. Automatic current sharing (Current Sharing Mechanism CSM) is an advanced way to distribute heat generation in multi-phase switching topologies at full load. A two-phase series capacitor buck converter (2-pscB) …

Tutors’ Beliefs About Language And Roles: Practice As Language Policy In Emi Contexts, Marion Heron, Doris Dippold, Necmi Aksit, Tijen Aksit, Jill Doubleday, Kara Mckeown

All Works

It has been well established that for all students, but particularly second language (L2) English speaking students, academic English speaking skills are key to developing specialist terminology and disciplinary content in an English as a medium of instruction (EMI) context. However, what is less clear in many contexts is the institutional language policy necessary to guide and support both L2 English speaking students and disciplinary tutors. In this paper, we focus on disciplinary tutors’ beliefs of language and their roles with respect to language support to surface implicit and covert language policies. We argue that in the absence of explicit …

Revisiting Attitudes Towards English In Cameroon And The Rush For Emi: Positioning Education For All Vision, Eric Enongene Ekembe

Journal of English Learner Education

The rush to English and English medium education (EMI) is fashionably a global tendency, and research in the domain has extensively explored the effects of such rush on social justice, quality education, economic and power dynamics across contexts. Given the multifaceted challenges related to the provision of English and accessibility to EMI, the relationship between UNESCO’s Education For All vision and access to English tends to be complicated. This paper examines the commonly-stated quest for English in Cameroon with a focus on attitudes towards English and EMI. The purpose is to understand the interface between the rush to EMI and …

Adaptive Interference Mitigation Using Frequency-Selective Limiters Over Gps Band For Automotive Applications, Mahima Shukla, Marina Y. Koledintseva, Michael Geiler, Scott Gillette, Michael Hunnewell, Anton L. Geiler

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, we address the challenges associated with the necessity to protect Global Positioning system (GPS) receivers from various types of electromagnetic interference (EMI) generated by internal or external sources. We have developed a compact, lightweight, and passive frequency selective limiter (FSL) technology that automatically and adaptively protects vulnerable input circuits of a GPS receiver from unwanted emissions and prevents a GPS receiver from going into saturation. This technology is based on using magnetostatic surface waves in a magnetically biased ferrite film. The nonlinear processes in ferrite films enable discrimination of signals based on their power levels. In these …

A Study Of The Difficulties And Instructional Support Related To Spoken Interaction In An Emi Course For Higher Education Students, Mei-Ying Chien, Martin Valcke

Journal of Educational Research and Practice

The use of English as a medium of instruction (EMI) in higher education is considered a vehicle in non-English speaking countries for the purpose of internationalization, enhancing students’ employability, and international competition. Many higher education institutions in Europe adapted their curriculum and started teaching in English, while enrolling international students from Erasmus programs and non-European countries. This study builds on an EMI course set within a Belgian university. Six L2 (English as a second Language) students were interviewed to identify and explore their motivation, difficulties, and instructional support as it relates to their spoken interaction during the class. The findings …

Switching Trajectory Control For High Voltage Silicon Carbide Power Devices With Novel Active Gate Drivers, Shuang Zhao

Graduate Theses and Dissertations

The penetration of silicon carbide (SiC) semiconductor devices is increasing in the power industry due to their lower parasitics, higher blocking voltage, and higher thermal conductivity over their silicon (Si) counterparts. Applications of high voltage SiC power devices, generally 10 kV or higher, can significantly reduce the amount of the cascaded levels of converters in the distributed system, simplify the system by reducing the number of the semiconductor devices, and increase the system reliability.

However, the gate drivers for high voltage SiC devices are not available on the market. Also, the characteristics of the third generation 10 kV SiC MOSFETs …

Practical Methods For Source Separation In Emc Measurements, Yuanzhuo Liu

Masters Theses

"Electromagnetic emission is critical in the electronic industry with the rapid growth of the development of the electronic device. To identify the emission from the multipule sources, two methods are proposed in the near field scan and total radiated power measurement respectively.

The first method can be applied in the measurement of the field generated by multiple non-correlated sources. The contribution of each source is determined using a blind source separation (BSS) technique. The measurements are performed using one scanning probe and stationary reference probes, avoiding the need to measure the spatial correlations of the random field. The resolving result …

Developing A Methodology For Estimating The Growth Of Radiated Emission From Multi-Modular Systems, Kaustav Ghosh

Masters Theses

"The large multiscale problems are commonly faced in real-world applications such as analysis of electromagnetic interference for a printed circuit board installed on a large platform with connected cables, wires and other high speed interfaces. EMI problems are not uncommon in high speed systems which involve multiple modules of complex hardware. As the system clock frequency and data rate increases, so does the challenges in controlling the EMI in such systems. The costs to prototype and to develop networking equipment are growing as a result of increasing complexities and densities. EMC regulations require radiated emission testing to be done in …

A Gan-Based Synchronous Rectifier With Reduced Voltage Distortion For 6.78 Mhz Wireless Power Applications, Spencer Pierce Cochran

Masters Theses

The call for a larger degree of engineering innovation grows as wireless power transfer increases in popularity. In this thesis, 6.78 MHz resonant wireless power transfer is explained. Challenges in WPT such as dynamic load variation and electromagnetic interference due to harmonic distortion are discussed, and a literature review is conducted to convey how the current state of the art is addressing these challenges.A GaN-based synchronous rectifier is proposed as a viable solution, and a model of the circuit is constructed. The precisely derived model is compared to a linearized model to illustrate the importance of exactness within the model …

A Novel Data Pattern Dependent Electromagnetic Emission Modeling For High Speed Multi-Channel Interconnects, Nick K.H. Huang, Li (Lijun) Jun Jiang, Xingyun Luo, Huichun Yu, Huasheng Ren

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic interference (EMI) is becoming more serious when the data rate of the digital system continues increasing. However, its modeling and analysis are very challenging. In this paper, a novel electromagnetic superposition method is developed to model the electromagnetic emission for the high speed multi-channels on IC packagings. It employs the equivalence principle to obtain the electromagnetic field response over a broad spectrum. Then it uses the linear property of the passive parasitic system to superpose the contribution of different signal patterns. As a result, with limited pre-calculations, it is very convenient to compute the electromagnetic emission efficiently from different …

Reduction Of Emi Due To Common Mode Current Using Common Mode Filter Or Lossy Material, Qian Liu

Masters Theses

"This thesis consists of four papers. In the first paper, two new common mode filter structures were designed, fabricated, and measured. A "sandwich-type" EBG structure that resonates at the desired filter frequency is designed to suppress common mode filter on differential signals. The new filters are placed on top of the PCB as a surface-mount component, instead of being implemented within the PCB stackup. The total radiated power (TRP) of the implemented filter is investigated and discussed. RF absorbing material and traditional shielding are considered to reduce the TRP.

In the second paper and third paper, new PCB-embedded common mode …

Viability Of The Use Of Electromagnetic Induction To Predict Streambed Properties, Alexandra R. Hruby

UCARE Research Products

This study examined whether electromagnetic induction is a reliable tool to predict various streambed properties, including water conductivity, water temperature, and hydraulic conductivity. The test site was along the North Loup River, outside of St. Paul, Nebraska. Electromagnetic induction was performed using a field portable, multi-frequency EMI tool. Hydraulic conductivity was measured using the falling-head permeameter test, and water temperature and conductivity were measured using handheld meters. The study found that there is a strong positive correlation between water conductivity and apparent electrical conductivity measured by electromagnetic induction. This relationship can be explored further through the analysis of spatial patterns …

Fast Data Pattern Based Electromagnetic Interference Evaluation For Ic Packaging, Nick K.H. Huang, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic interference (EMI) is becoming more serious when the data rate of the digital system continues increasing. However, its modeling and analysis are very challenging. In this paper, a novel electromagnetic superposition method is developed to model the IC packaging electromagnetic emission. It employs the equivalence principle to obtain the electromagnetic field response over a broad spectrum. Then it uses the linear property of the passive parasitic system to superpose the contribution of different signals on the packaging. As a result, with certain pre-calculations, it is convenient to compute the electromagnetic emission efficiently from different signals with various data pattern …

The Development Of Near Field Probing Systems For Emc Near Field Visualization And Emi Source Localization, Hui He

Masters Theses

"The objectives of this research are to visualize the frequency dependent electromagnetic field distribution for electromagnetic compatibility (EMC) applications and the radiating source reconstruction on complex shaped electronic systems. This is achieved by combining near field probing with a system for automatically recording the probe position and orientation. Due to the complexity of the shape of the electronic systems of interest, and for utilizing the expertise of the user, the probe will be moved manually not robotically. Concurrently, the local near field will be recorded, associated with the location and displayed at near real time on the captured 3D geometry …

Improving And Expanding The Capabilities Of The Poly-Picosatellite Orbital Deployer, David Pignatelli

Master's Theses

The Poly-Picosatellite Orbital Deployer (P-POD) has undergone a series of revisions over the years. The latest revision, described in this Master’s Thesis, incorporates new capabilities like EMI shielding, an inert gas purge system, and an electrical interface to the CubeSats after they are integrated into the P-POD. Additionally, some mass reduction modifications are made to the P-POD, while its overall strength is increased. The P-POD inert gas purge system successfully flew, on a previous revision P-POD. The P-POD components are analyzed to a set of dynamic loads for qualification, and successfully undergoes random vibration qualification testing. The P-POD encounters some …

High Density Emi Filter Design In High Power Three-Phase Motor Drive Systems, Jing Xue

Doctoral Dissertations

High density EMI filter is important in the application of more-electric-aircraft (MEA). In this work, the author is focusing on several major aspects of EMI filter design that would influence the power density.

In Chapter 1, the feature of EMI study and conventional design methods are reviewed.

The interaction between the common-mode (CM) and differential-mode (DM) noise is one key factor introducing unnecessary weight to EMI filter design. In Chapter 2, the author explains the origin of the mixed-mode (MM) noise on the output side of three-phase motor drives. Experimental results have verified the existence of the MM noise in …

Emission Source Microscopy For Electromagnetic Interference Source Localization, Pratik Rajesh Maheshwari

Doctoral Dissertations

"For complex and large systems with multiple sources, it is often difficult to localize the sources of radiation. Near-field electromagnetic scanning is used often for root-cause diagnosis by determining field distribution close to the PCB. In the near-field, the evanescent waves are dominant, which may lead to the misinterpretation of them being the dominant sources contributing to the far-field. Another limitation of near-field scanning is that the probe may not be able to access all locations near the PCB due to the complex geometry and high component density. Two-dimensional synthetic aperture radar is a well-known technique used for antenna diagnostic …

Data Pattern Based Electromagnetic Interference Modeling For Ic Packaging, Nick K.H. Huang, Tao Wang, Li (Lijun) Jun Jiang, X. Y. Xiong

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic interference (EMI) is becoming more serious when the data rate of the digital system continues increasing. However, its modeling and analysis are very challenging. In this paper, a novel electromagnetic superposition method is developed to model the IC packaging electromagnetic emission. It employs the equivalence principle to obtain the electromagnetic field response over a broad spectrum. Then it uses the linear property of the passive parasitic system to superpose the contribution of different signals on the packaging. As a result, with certain pre-calculations, it is convenient to compute the electromagnetic emission efficiently from different signals with various data pattern …

Fundamental Components Of The Ic Packaging Electromagnetic Interference (Emi) Analysis, Nick K.H. Huang, Li (Lijun) Jun Jiang, Huichun Yu, Gang Li, Shuai Xu, Huasheng Ren

Electrical and Computer Engineering Faculty Research & Creative Works

The IC packaging EMC/SI/PI problems have been broadly attested. But IC packaging EMI was seldom addressed. Because the EMI emission by IC packagings is increasingly significant, in this paper, EMI behaviors are systematically studied. To fundamentally understand the radiation mechanism, radiated contributions from ground lids, vias, and traces of the packaging are investigated and modeled separately. It is seen that the packaging EMI has clearly low frequency and high frequency behaviors. The low frequency behavior is due to the Hertzian dipole effects of vias. The high frequency behavior is due to the radiation of excited cavity modes. Both theoretical analysis …

Design And Control Of High Power Density Motor Drive, Dong Jiang

Doctoral Dissertations

This dissertation aims at developing techniques to achieve high power density in motor drives under the performance requirements for transportation system. Four main factors influencing the power density are the main objects of the dissertation: devices, passive components, pulse width modulation (PWM) methods and motor control methods.

Firstly, the application of SiC devices could improve the power density of the motor drive. This dissertation developed a method of characterizing the SiC device performance in phase-leg with loss estimation, and claimed that with SiC Schottky Barrier Diode the advantage of SiC JFET could benefit the motor drive especially at high temperature. …

Linguistic Outcomes Of English Medium Instruction Programmes In Higher Education: A Study On Economics Undergraduates At A Catalan University, Jennifer Rose Ament, Carmen Pérez-Vidal

Higher Learning Research Communications

Globalisation and international mobility in the 21st century has led to the internationalisation of the English language (Crystal, 2003). Research regarding linguistic gains at university levels is however extremely scarce. This study aims to address this gap of knowledge and provide some answers as to how much linguistic gain can be expected after one year of English medium instruction. Two groups of undergraduate students enrolled in different levels of English medium instruction (EMI) were given a pre and post-test over a 1 year period. Results were analysed statistically; significant gains were found only in the semi- immersion group in the …

Realizing Internationalization At Home Through English-Medium Courses At A Japanese University: Strategies To Maximize Student Learning, Yukiko Ishikura

Higher Learning Research Communications

In 2009, the Japanese government launched the Global 30 (G30) Project, a new initiative to internationalize universities. Selected universities had to create English-medium degree programs at undergraduate level in order to stimulate “internationalization at home.” The G30 Project represented a major shift in the focus of internationalization efforts from quantitative to qualitative outcomes. Using a case study approach, this paper investigates one G30 program and the attempts made to open up English-medium course offerings to the wider student body. It explores two related issues: level setting and student attrition. A mixed methods approach was used with data gathered from students …

Improving Bilingual Higher Education: Training University Professors In Content And Language Integrated Learning, Birgit Strotmann, Victoria Bamond, José M. López Lago, María Bailen, Sonia Bonilla, Francisco Bonilla Montesinos

Higher Learning Research Communications

Few studies have been conducted at the tertiary level on Content and Language Integrated Learning (CLIL). The current study aims to gather and share preliminary data concerning CLIL in higher education at several universities in different countries. A questionnaire and brief description of the project and its objectives were emailed to all teachers at a Spanish university listed as having taught content courses in English in the last academic year, and to all the Language Center directors within the network with instructions to pass the questionnaire along to the CLIL teachers at their respective universities. The questionnaire was answered by …

Pulse Density Modulated Soft Switching Cycloconverter, Jesse Timothy Adamson

Master's Theses

Single stage cycloconverters generally incorporate hard switching at turn on and soft switching at turn off. This hard switching at turn on combined with the slow switching speeds of thyristors (the switch of choice for standard cycloconverters) limits their use to lower frequency applications.

This thesis explores the analysis and design of a pulse density modulated (PDM), soft switching cycloconverter. Unlike standard cycloconverters, the controller in this converter does not adjust thyristor firing angles. It lets only complete half cycles of the input waveform through to the output. This allows and requires a much greater frequency step down from the …

Design Considerations To Reduce Conducted And Radiated Emi, Matthew J. Schneider

Purdue Polytechnic Masters Theses

This work evaluates the effects of conducted and radiated EMI due to improperly designed circuits or printed circuit board (PCB) layouts. Common circuits used in a wide range of electronic devices are evaluated using both good and poor design techniques. Additional evaluations are performed to measure the effects of EMI on cabling used for digital communication or RF purposes. Finally, a consumer product is evaluated which must pass regulatory agency requirements in order to be sold in the consumer market. Potential solutions to common EMI problems are then implemented and discussed. This work will look at individual circuits and evaluate …

Salinity Inventory And Tolerance Screening In Utah Agriculture, Austin Mccoy Hawks

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil salinity, a yield-limiting condition, has plagued crop production for centuries by reducing crop productivity. Research has introduced methods for successfully managing soil salinity. This research discusses the adaptation of established management methods to create new soil salinity management techniques.

One adapted technique is an automated crop screening apparatus. A new design was created and successfully used in rapidly screening two strawberry cultivars to determine their tolerance to salinity. Screening crops and determining their tolerance to yield-limiting conditions are essential in managing soil salinity.

Another salinity management tool used in this research was electromagnetic induction (EMI). EMI was used to …