Cross-border Conflict Drivers and Breaks – Pakistan, Afghanistan, Iran and Iraq

This report provides an overview of the evidence on cross-border conflict drivers and breaks along the Pakistan–Afghanistan–Iran–Iraq route. Direct evidence on the nature of conflict-related flows along this route in its entirety is limited. Therefore, this report includes evidence on crossborder conflict dynamics between neighbouring countries along the route. This report was commissioned as an evidence mapping exercise, rather than aiming to carry out a full analysis of conflict dynamics across the four countries

Analysing and Modelling Particle Distributions in Near-Earth Space: Machine Learning

This thesis contains the analysis of 10 years of ESA Cluster observations using machine learning techniques. In the first study, we investigate solar wind electron populations at 1 au. In the second study, we apply a novel machine learning technique to magnetotail data in order to better characterise particle distribution function. In the third study, we make the first in-situ observations of the tearing instability leading to magnetic reconnection in the magnetotail. Solar wind electron velocity distributions at 1 au consist of three main populations: the thermal `core' population and two suprathermal populations called halo and strahl. We apply unsupervised algorithms to phase space density distributions, to perform a statistical study of how the core/halo and core/strahl breakpoint energies vary. The results of our statistical study show a significant decrease in both breakpoint energies against solar wind speed. By fitting Maxwellians to the core, based on our study, we can discuss the relative importance of the core temperature on halo and strahl electrons. Collisionless space plasma environments are characterised by distinct particle populations that typically do not mix. Although moments of their velocity distributions help in distinguishing different plasma regimes, the distribution functions themselves provide more comprehensive information about the plasma state. By applying dimensionality reduction and clustering methods to electron distributions in pitch angle and energy space, we distinguish between the different plasma regions. We identify several new distinct groups of distributions, that are dependent upon significantly more complex plasma and field dynamics. Magnetic reconnection is a fundamental mechanism responsible for explosive energy release in space and laboratory plasmas. The onset of reconnection is via the tearing instability. Due to its elusive nature, there is an absence of in-situ observations of the tearing instability. We present the first direct observations of the tearing instability and the subsequent evolution of plasma electrons and reconnection, using neural network outlier detection methods. Our analysis of the tearing instability and subsequent reconnection provides new insights into the fundamental understanding of the mechanism responsible for reconnection

Blowing off Steam Tables

In thermodynamics courses, there is appreciable time and effort devoted to teaching steam tables. Despite this, students still find the ability to use steam tables for retrieving thermodynamic properties a challenging skill to master. The challenges arise from the need to interpolate, the need to identify the correct region, and the requisite familiarity with property trends. The use of steam tables to retrieve thermodynamic properties is often presented to students as a keystone skill for subsequent study of steam power plants. However, if graduates do not require this skill in practice, perhaps we are simply teaching an obsolete system that serves the course objectives but not beyond. Several compelling alternatives exist. Among them, computerized thermodynamic property databases for common substances are readily available and can rapidly supply state properties. However, we want to avoid tools that simply supply property values without reinforcing thermodynamic fundamentals. For instance, steam tables can supply accurate property values, but they fail to emphasize the interdependence of these properties. Instead, the use of property diagrams to solve thermodynamic problems can greatly improve students’ understanding of thermodynamics by visualizing property relationships. As a highly visual and intuitive tool, property diagrams eliminate the time devoted to mastering steam tables. After teaching steam tables for multiple years within a year-long thermal-fluid sciences course and recognizing the poor pedagogic utility, the steam tables were entirely replaced by the temperature-entropy diagram as the primary source for water thermodynamic properties. This paper discusses the implementation, challenges, and the outcomes of this introduction. Apart from developing instructions aligned solely to property diagrams, a number of visual tools were identified, adopted, and developed to facilitate the transition. The overall outcomes were notably positive from a student learning perspective. Students quickly became comfortable using the T-s diagrams to solve the same textbook problems they would have solved using steam tables. The loss of accuracy was more than made up by their ability to quickly identify a state and retrieve its properties. Furthermore, students improved their ability to predict property trends when compared to students who relied primarily on steam tables. The results highlight the need for change in thermodynamics pedagogy by abandoning steam tables and emphasizing the fundamentals necessary to study steam power plants

Upgrading the capstone projects: The engineering clinic model

Capstone engineering design projects are ideal for broad application of engineering concepts on open-ended research and design problems. These projects allow students to reinforce their skills and extend their expertise into specialized areas of interest. Often, the capstone projects serve as both test grounds and launch pads for students’ engineering careers. Within the engineering curriculum, these projects typically span the final year of an engineering program and entail a single project within a single disciplinary area. While their significance to the educational experience is unequivocal, the benefits of a capstone project can be expanded to further reflect real-world experiences. Over the span of their careers, professional engineers work on a number of projects and assume a variety of roles within a team of engineers with a range of expertise. How do we model that experience for our students within engineering education? Rowan University’s Henry M. Rowan College of Engineering adopted the Engineering Clinic Model (ECM) to replace capstone projects. With ECM students choose to work across traditional disciplinary boundaries on multiple projects over their junior and senior years. The Junior and Senior Engineering Clinics allow students to work on potentially four distinct projects with both juniors and seniors from any engineering discipline supervised by a faculty. The student teams focus on tangible objectives and present their outcomes for each term before moving to another team. The ECM has demonstrated tremendous resilience against enrollment growth and continues to be the most notable aspect of Rowan Engineering. Its resilience can be attributed to an automated process that prioritizes student preferences and faculty interests. The process begins with faculty from every engineering discipline pitching their projects at the start of the term. Students subsequently rank their preferences for those projects. A custom-developed Clinic Match algorithm assigns students to their projects based on a set criteria. The greatest benefit of this approach has been for the students to build desired competencies in a wide range of fields, regardless of the discipline. For the Spring 2019 semester, over 150 distinct projects, representing 5 engineering disciplines, were pitched to over 500 junior and senior engineering students. Students worked in teams typically ranging from 3-8 members on projects; often funded by the government and industry. This paper highlights the key features of engineering clinics within junior and senior years and supports the outcomes with quantitative trends gathered over the past 10 semesters. The Junior and Senior Engineering Clinics offer a powerful alternative for leveraging the capstone design project to impart a broad skill set among engineering graduates

Touching Water: Exploring Thermodynamic Properties with Clausius App

The effect of pressure and temperature on the properties of water is a critical concept within engineering curriculum. Instructors spend considerable effort training students to use reference databases; traditionally in tabulated forms or more recently with use of computer-aided references. The reliance on tables however, places undue emphasis on the property values over property relationships. Understanding thermodynamic relationships and the trends are of greater value from a student learning perspective than the numeric value of the properties. This value is highlighted by the practice of asking students to sketch thermodynamic cycles on a temperature-entropy T-s or pressure-volume P-v chart. The typical analytical steps involving property retrieval followed by depiction on a property chart is disjointed and reversed. If property values are acquired directly from a T-s or P-v property chart, the process is integrated into a single intuitive step that promotes deeper understanding. While printed charts exist, they can be challenging to read considering a single point must supply up to six discrete values (namely P, T, v, u, h, and s). Instead, an interactive property chart that displays properties values for states identified by the user can be highly effective. This was the inspiration behind the Clausius app. Clausius allows users to simply tap on a desired state within a T-s chart to retrieve property values. The design was driven by the need to visualize thermodynamic property relationships as opposed to simply delivering property values. The app was subsequently studied in thermodynamics courses for its impact on student learning (with a treatment group) when compared to accessing properties via steam tables (with a control group). The intervention involved a guided exploration of water properties by the participants, followed by an assessment of students’ understanding of the property trends. Three sets of treatment and control groups participated, across two campuses and three departments. The outcomes provide a strong endorsement for Clausius and its ability to teach property trends. Student feedback also supported the advantages of more visual and dynamic reference for water properties. Overall, enabling students to ‘touch and explore’ thermodynamic properties seems more intuitive and conducive to deeper learning than the traditional use of tabulated property values

Consumer Reports Inspired Introduction to Engineering Project

Freshman engineering courses play a crucial role in educating students about the various engineering disciplines and their functions, in addition to establishing a strong analytical foundation. Recognizing the importance of basic experimentation techniques, a new freshman engineering project was designed to expose students to the overall engineering profession with emphasis on developing fundamental technical and laboratory skills. The project was inspired by the popular Consumer Reports magazine, which publishes reviews of consumer products upon rigorous testing and analytical surveys. Specifically, we note the strong overlap between core functions of an engineer and the process with which Consumer Reports reviews are generated. Freshman students were asked to select three brands of a consumer product for their review with instructor consultation. The products ranged from well-marketed kitchen tools to popular children’s toys. The student teams designed experiments to systematically test quantifiable properties of these products, analyze the data and recommend a specific brand. The project enabled students to practice core engineering functions such as design of experiments,measurement, data analysis, and representation. In essence developing laboratory skills without necessarily requiring a strong theoretical understanding to conduct the experiments. Most importantly, the project afforded students the autonomy to design their own sub-project within the provided constraints. The students also recognized the importance of soft skills such as teamwork, effective communication, and project management in achieving their purpose of identifying a superior brand. This paper presents the overall scope of the project and its outcomes, including the details for adopting the Consumer Reports Project within a freshman engineering course or, alternatively, in a high school technical course. The paper highlights implementation, including project milestones, and assessment of this highly student-driven hands-on project. Pre- and post-tests were conducted to assess the effectiveness of the project in achieving the project objectives. Formative student surveys indicated a very positive response to the project, acknowledging the independence of product selection as the key aspect in making the project engaging. The highly flexible and scalable aspects of the project make it ideal as an introductory engineering project focused on developing a strong experimental foundation, at the same time providing a broad overview of the engineering profession

The Effects of Two Thick Film Deposition Methods on Tin Dioxide Gas Sensor Performance

This work demonstrates the variability in performance between SnO2 thick film gas sensors prepared using two types of film deposition methods. SnO2 powders were deposited on sensor platforms with and without the use of binders. Three commonly utilized binder recipes were investigated, and a new binder-less deposition procedure was developed and characterized. The binder recipes yielded sensors with poor film uniformity and poor structural integrity, compared to the binder-less deposition method. Sensor performance at a fixed operating temperature of 330 °C for the different film deposition methods was evaluated by exposure to 500 ppm of the target gas carbon monoxide. A consequence of the poor film structure, large variability and poor signal properties were observed with the sensors fabricated using binders. Specifically, the sensors created using the binder recipes yielded sensor responses that varied widely (e.g., S = 5 – 20), often with hysteresis in the sensor signal. Repeatable and high quality performance was observed for the sensors prepared using the binder-less dispersion-drop method with good sensor response upon exposure to 500 ppm CO (S = 4.0) at an operating temperature of 330 °C, low standard deviation to the sensor response (±0.35) and no signal hysteresis

Combustion Synthesis of Fe-Incorporated SnO2 Nanoparticles Using Organometallic Precursor Combination

Synthesis of nanomaterials within flames has been demonstrated as a highly scalable and versatile approach for obtaining a variety of nanoparticles with respect to their chemistry, composition, size, morphology, and dimensionality. Its applicability can be amplified by exploring new material systems and providing further control over the particle characteristics. This study focused on ironincorporated SnO2 nanoparticles generated using an inverse coflow diffusion flame burner that supported a near-stoichiometric methane-air combustion. A liquid organometallic precursor solution of Sn(CH3)4 and Fe(CO)5 was used to produce 11–14 nm nanocrystalline particles. Synthesized particles were analyzed using TEM, XRD, and XEDS to characterize for size and composition. A flame temperature field was obtained to map particle evolution within the flame. A range of conditions and parameters were studied to specifically generate targeted particles. The study augments related research towards increasing the production potential of combustion synthesis

Statistics of Solar Wind Electron Breakpoint Energies Using Machine Learning Techniques

Solar wind electron velocity distributions at 1 au consist of a thermal "core" population and two suprathermal populations: "halo" and "strahl". The core and halo are quasi-isotropic, whereas the strahl typically travels radially outwards along the parallel and/or anti-parallel direction with respect to the interplanetary magnetic field. With Cluster-PEACE data, we analyse energy and pitch angle distributions and use machine learning techniques to provide robust classifications of these solar wind populations. Initially, we use unsupervised algorithms to classify halo and strahl differential energy flux distributions to allow us to calculate relative number densities, which are of the same order as previous results. Subsequently, we apply unsupervised algorithms to phase space density distributions over ten years to study the variation of halo and strahl breakpoint energies with solar wind parameters. In our statistical study, we find both halo and strahl suprathermal breakpoint energies display a significant increase with core temperature, with the halo exhibiting a more positive correlation than the strahl. We conclude low energy strahl electrons are scattering into the core at perpendicular pitch angles. This increases the number of Coulomb collisions and extends the perpendicular core population to higher energies, resulting in a larger difference between halo and strahl breakpoint energies at higher core temperatures. Statistically, the locations of both suprathermal breakpoint energies decrease with increasing solar wind speed. In the case of halo breakpoint energy, we observe two distinct profiles above and below 500 km/s. We relate this to the difference in origin of fast and slow solar wind.Comment: Published in Astronomy & Astrophysics, 11 pages, 10 figure