Pneumatic ore concentration

The concentration of lead and zinc ores by means of air is practically an unexplored field, although the subject is by no means a new one. Considerable research work has been done and several methods, processes and machines have been developed, but little or nothing has been accomplished towards making air separation a success. the lack of success has been due mainly to two reasons:- (1) That very little has been known about the internal conduct of air currents, and (2) that nearly all methods and machines so far worked out have presupposed the fact that the ore to be separated should not come into direct contact with the air currents. In this thesis the work will be done under the assumption that air currents act or can be made to act with much greater regularity than has hitherto been supposed --Introduction, page 1

Collaborating With Writing Centers on Interdisciplinary Peer Tutor Training to Improve Writing Support for Engineering Students

Introduction: Faculty members have little time and usually lack expertise to provide writing feedback on lab reports. Sending students to a writing center, an existing resource on virtually all college campuses, could fill that gap. However, the majority of peer writing tutors are in nontechnical majors, and little research exists on training them to provide support for engineering students. Research question: Can peer writing tutors without technical backgrounds be trained to provide effective feedback to engineering students? About the case: Previously, sending students to the writing center was ineffective. The students did not see the value, and the tutors did not feel capable of providing feedback to them. To remedy this situation, an interdisciplinary training method was developed collaboratively by an engineering professor and the writing center director. Situating the case: Researchers have suggested that effective writing center help for engineering students is possible, and the authors have designed an interdisciplinary training method that has produced positive results. Supporting literature includes the use of generalist tutors, writing in the disciplines, genre theory, and knowledge transfer. Methods/approach: This was a three-year experiential project conducted in a junior-level engineering course. The assignment, a lab report, remained the same. Qualitative and quantitative data were collected from students and tutors. Results/discussion: Tutor feedback and student satisfaction significantly improved. However, a few students who were satisfied overall still expressed interest in having their reports reviewed by a tutor with a technical background. Conclusions: Interdisciplinary tutor training can improve the feedback of peer writing tutors, providing support for faculty efforts to improve student writing. The method requires minimal faculty time and capitalizes on existing resources

Developing a PV and Energy Storage Sizing Methodology for Off-Grid Transactive Microgrids

A simulation tool was developed through MATLAB for comparing Centralized Energy Sharing (CES) and Interconnected Energy Sharing (IES) operating strategies with a standard Stand-Alone Photovoltaic System (SAPV). The tool can be used to investigate the effect of several variables on cost and trading behavior including: initial charge of Energy Storage System (ESS), amount of load variability, starting month, number of stand-alone systems, geographic location, and required reliability. It was found that the CES strategy improves initial cost by 7% to 10% compared to a standard SAPV in every simulation. The IES case consistently saved money compared to the baseline, just by a very small amount (less than 1%). The number of systems did not have a demonstrable effect, giving the same cost per system whether there were 2 systems or 50 involved in the trading strategies. Geographic locations studied (Indianapolis, Indiana; Phoenix, Arizona; Little Rock, Arkansas; and Erie, Pennsylvania) showed a large variation on the total installed cost with Phoenix being the least expensive and Erie being the most expensive location. Required reliability showed a consistent and predictable effect with cost going down as the requirement relaxed and more hours of outage were allowed

Comparison of Undergraduate Student Writing in Engineering Disciplines at Campuses with Varying Demographics

Writing is generally recognized as fundamental to the formation and communication of scientific and technical knowledge to peer groups and general audiences. Often, persuasive writing is an essential attribute emphasized by industries and businesses for a successful career in STEM fields. Nevertheless, the current scenario is that students in STEM fields, with their increased demand for more specialized skills in fewer credit hours combined with a lack of emphasis on writing from engineering faculty members, make addressing this need difficult. In addition, students in engineering fields often do not value writing skills and underestimate the amount of writing they will do in their careers. Hence, it is essential to understand and quantify the level of writing skills STEM students exhibit in their technical courses so that mitigation efforts can be designed using commonly available resources to enhance this important skillset among the students, including university writing centers. A research question was posed to study this aspect of technical writing: How do STEM students at institutions conceive of writing and its role in classroom laboratories? This research was conducted at three different universities with students of varied demographics, including one which is designated as a Hispanic-serving institution, via a sequential mixed-methods design. The demography variation among the institutions includes the level of college preparation among students and the mix of ethnicity to see if there are variations among certain groups. Although the sample size is small, the goal was to establish a methodology and a preliminary outcome set that could be used in further research with larger populations. Research data in the form of reports and surveys, were collected from groups of students from four distinct campuses to ascertain the technical writing capability of each group and provide a comparison to better understand the level of intervention required. The quantitative data was collected throughout the academic year through Likert scale surveys as well as rubric-based evaluation of reports. The research design, methodology, and results of the research findings and the proposed mitigation efforts to improve student writing in STEM fields are presented in the paper

Industrial Sponsor Perspective On Leveraging Capstone Design Projects To Enhance Their Business

Capstone design projects have become commonplace among engineering and engineering technology programs.  These projects are valuable tools when assessing students, as they require students to work in teams, communicate effectively, and demonstrate technical competency.  The use of industrial sponsors enhances these projects by giving these projects more of a “real world” feel.  Most of the research into capstone design projects focuses on student learning as well as the overall design process.  However, very little research has been performed from the perspective of the industrial sponsor.  In this paper, an industrial sponsor who has sponsored several large-scale capstone design projects presents their perspective on working with students on these projects.  These projects serve as training systems for their existing employees and clients, and offer the sponsor the opportunity to evaluate the students as prospective future employees

Quasi Self-Excited DFIG-Based Wind Energy Conversion System

This article introduces a new configuration of the doubly-fed induction generator (DFIG) based wind energy conversion system (WECS) employing only a reduced-size rotor side converter (RSC) in tandem with a supercapacitor. In the proposed structure, the grid side converter (GSC) utilized in conventional DFIG-based WECSs is successfully eliminated. This is accomplished by employing the hydraulic transmission system (HTS) as a continuously variable and shaft decoupling transmission unit. This transforms the conventional constant-ratio drives by providing an opportunity to control the power flow through the generator's rotor circuit regardless of the wind turbine's shaft speed. This feature of HTS can be utilized to control the RSC power and ultimately regulate the supercapacitor voltage without a need for GSC. The proposed system is investigated and simulated in MATLAB Simulink at various wind speeds to validate the results and demonstrate the dynamic performance of the system

Board 121: Using Tutor-led Support to Enhance Engineering Student Writing for All

Writing Assignment Tutor Training in STEM (WATTS) is part of a three-year NSF IUSE grant with participants at three institutions. This research project seeks to determine to what extent students in the WATTS project show greater writing improvement than students using writing tutors not trained in WATTS. The team collected baseline, control, and experimental data. Baseline data included reports written by engineering and engineering technology students with no intervention to determine if there were variations in written communication related to student demographics and institutions. Control data included reports written by students who visited tutors with no WATTS training, and experimental data included reports written by students who visited tutors who were WATTS-trained. Reports were evaluated by the research team using a slightly modified version of the American Association of Colleges and Universities (AAC&U) Written Communication VALUE Rubric. Baseline data assessment also provided an opportunity to test the effectiveness of the rubric. This paper presents findings from the analysis of the control and experimental data to determine the impact of WATTS on student writing in lab reports. An aggregate score for each lab report was determined by averaging the reviewer scores. An analysis was run to determine if there was a statistical difference between pre-tutoring lab report scores from the baseline, control, and experimental rubric scores for each criterion and total scores; there was not a statistically significant difference. The research team ran a Wilcoxon signed-rank test to assess the relationship between control and experimental aggregate rubric scores for each criterion. The preliminary analysis of the control and experimental data shows that the WATTS intervention has a positive, statistically significant impact on written communication skills regardless of the campus student demographics. Since WATTS has been shown to be a low-cost, effective intervention to improve engineering and engineering technology students’ written communication skills at these participating campuses, it has potential use for other institutions to positively impact their students’ written communication

Board 317: Improving Undergraduate STEM Writing: A Collaboration Between Instructors and Writing Center Directors to Improve Peer-Writing Tutor Feedback

Undergraduate STEM writing skills, especially in engineering fields, need improvement. Yet students in engineering fields often do not value writing skills and underestimate the amount of writing they will do in their careers. University writing centers can be a helpful resource, but peer writing tutors need to be prepared for the differences between writing for the humanities and writing in STEM fields. The Writing Assignment Tutor Training in STEM (WATTS) model is designed to improve tutor confidence and student writing. In this innovative training, the writing center supervisor collaborates with the STEM instructor to create a one-hour tutor-training where the tutors learn about the assignment content, vocabulary, and expectations. This multidisciplinary collaborative project builds on previous investigative work to determine the impact of WATTS on students, tutors, and faculty and to identify its mitigating and moderating effects. Data has been collected and analyzed from pre- and post- training surveys, interviews, and focus groups. In addition, the project studies WATTS effects on student writing pre- and post-tutoring. The team will use these results to develop a replicable, sustainable model for future expansion to other institutions and fields. By systematically collecting data and testing WATTS, the investigators will be able to identify its mitigating and moderating effects on different stakeholders and contribute valuable knowledge to STEM fields. This approach assesses the elements of the model that have the most impact and the extent to which WATTS can be used to increase collaboration between engineering instructors and writing centers. The project enables the investigators to expand WATTS to additional engineering courses, test key factors with more instructors, refine the process, and position WATTS for dissemination to a broad audience. As the cost of higher education rises, institutions are pressured to graduate students in four years and engineering curricula are becoming more complex. WATTS presents an economical, effective method to improve student writing in the discipline. Several factors indicate that it has the potential for broad dissemination and impact and will provide a foundation for a sustainable model for future work, as instructors become trainers for their colleagues, allowing additional ongoing expansion and implementation. WATTS serves as a model for institutions (large or small) to capitalize on existing infrastructure and resources to achieve large-scale improvements to undergraduate STEM writing while increasing interdisciplinary collaboration and institutional support

Using 81Kr and Noble Gases to Characterize and Date Groundwater and Brines in the Baltic Artesian Basin on the One-Million-Year Timescale

Analyses for $^{81}$Kr and noble gases on groundwater from the deepest aquifer system of the Baltic Artesian Basin (BAB) were performed to determine groundwater ages and uncover the flow dynamics of the system on a timescale of several hundred thousand years. We find that the system is controlled by mixing of three distinct water masses: Interglacial or recent meteoric water (\delta^{18}\text{O} \approx -10.4\unicode{x2030}) with a poorly evolved chemical and noble gas signature, glacial meltwater (\delta^{18}\text{O} \leq -18\unicode{x2030}) with elevated noble gas concentrations, and an old, high-salinity brine component (\delta^{18}\text{O} \geq -4.5\unicode{x2030}, \geq 90 \text{g Cl}^{-}/\text{L}) with strongly depleted atmospheric noble gas concentrations. The $^{81}$Kr measurements are interpreted within this mixing framework to estimate the age of the end-members. Deconvoluted $^{81}$Kr ages range from 300 ka to 1.3 Ma for interglacial or recent meteoric water and glacial meltwater. For the brine component, ages exceed the dating range of the ATTA 3 instrument of 1.3 Ma. The radiogenic noble gas components $^{4}$He* and $^{40}$Ar* are less conclusive but also support an age of > 1 Ma for the brine. Based on the chemical and noble gas concentrations and the dating results, we conclude that the brine originates from evaporated seawater that has been modified by later water-rock interaction. As the obtained tracer ages cover several glacial cycles, we discuss the impact of the glacial cycles on flow patterns in the studied aquifer system.Comment: Accepted for publication in Geochimica et Cosmochimica Act

Replication of a Tutor-Training Method for Improving Interaction Between Writing Tutors and Stem Students

The improvement of tutor training programs can impact the important work of writing centers. Tutors often feel less comfortable tutoring in genres different from their own discipline. A previous study introduced an assignment-specific tutor training model to improve writing center tutoring sessions between engineering students and writing tutors. The results of the previous study indicated a valuable addition to the resources available for engineering students. This model has now been replicated at two universities to assess the potential for wider dissemination. Preliminary data analysis suggests a relationship between initial tutor rating of student work, student perceptions of tutoring, and tutor perception of student engagement in the tutorial. Plans for future research include continued replication and expansion to test larger sample sizes, analysis of impact within and adaptations for other STEM areas, and continued study of the impact on tutoring team projects