The 7-channel FIR HCN Interferometer on J-TEXT Tokamak

A seven-channel far-infrared hydrogen cyanide (HCN) laser interferometer has been established aiming to provide the line integrated plasma density for the J-TEXT experimental scenarios. A continuous wave glow discharge HCN laser designed with a cavity length 3.4 m is used as the laser source with a wavelength of 337 {\mu}m and an output power up to 100 mW. The system is configured as a Mach-Zehnder type interferometer. Phase modulation is achieved by a rotating grating, with a modulation frequency of 10 kHz which corresponds to the temporal resolution of 0.1 ms. The beat signal is detected by TGS detector. The phase shift induced by the plasma is derived by the comparator with a phase sensitivity of 0.06 fringe. The experimental results measured by the J-TEXT interferometer are presented in details. In addition, the inversed electron density profile done by a conventional approach is also given. The kinematic viscosity of dimethyl silicone and vibration control is key issues for the system performance. The laser power stability under different kinematic viscosity of silicone oil is presented. A visible improvement of measured result on vibration reduction is shown in the paper.Comment: conference (15th-International Symposium on Laser-Aided Plasma Diagnostics

Jovian Plasma Modeling for Mission Design

The purpose of this report is to address uncertainties in the plasma models at Jupiter responsible for surface charging and to update the jovian plasma models using the most recent data available. The updated plasma environment models were then used to evaluate two proposed Europa mission designs for spacecraft charging effects using the Nascap-2k code. The original Divine/Garrett jovian plasma model (or "DG1", T. N. Divine and H. B. Garrett, "Charged particle distributions in Jupiter's magnetosphere," J. Geophys. Res., vol. 88, pp. 6889-6903,1983) has not been updated in 30 years, and there are known errors in the model. As an example, the cold ion plasma temperatures between approx.5 and 10 Jupiter radii (Rj) were found by the experimenters who originally published the data to have been underestimated by approx.2 shortly after publication of the original DG1 model. As knowledge of the plasma environment is critical to any evaluation of the surface charging at Jupiter, the original DG1 model needed to be updated to correct for this and other changes in our interpretation of the data so that charging levels could beproperly estimated using the Nascap-2k charging code. As an additional task, the Nascap-2k spacecraft charging tool has been adapted to incorporate the so-called Kappa plasma distribution function--an important component of the plasma model necessary to compute the particle fluxes between approx.5 keV and 100 keV (at the outset of this study,Nascap-2k did not directly incorporate this common representation of the plasma thus limiting the accuracy of our charging estimates). The updating of the DG1 model and its integration into the Nascap-2k design tool means that charging concerns can now be more efficiently evaluated and mitigated. (We note that, given the subsequent decision by the Europa project to utilize solar arrays for its baseline design, surface charging effects have becomeeven more of an issue for its mission design). The modifications and results of those modifications to the DG1 model to produce the new DG2 model presented here and the steps taken to integrate the DG2 predictions into Nascap-2k are described in this repor

What Else (Besides the Syllabus) Should Students Learn in Introductory Physics?

We have surveyed what various groups of instructors and students think students should learn in introductory physics. We started with a Delphi Study based on interviews with experts, then developed orthogonal responses to “what should we teach non‐physics majors besides the current syllabus topics?” AAPT attendees, atomic researchers, and PERC08 attendees were asked for their selections. All instructors rated “sense‐making of the answer” very highly and expert problem solving highly. PERers favored epistemology over problem solving, and atomic researchers “physics comes from a few principles.” Students at three colleges had preferences anti‐aligned with their teachers, preferring more modern topics, and the relationship of physics to everyday life and also to society (the only choice with instructor agreement), but not problem solving or sense‐making. Conclusion #1: we must show students how old physics is relevant to their world. Conclusion #2: significant course reform must start by reaching consensus on what to teach and how to hold students’ interest (then discuss techniques to teach it).National Science Foundation (U.S.) (NSF grant PHY-0757931

Alternating Current Corrosion of Carbon Steel

The objective was to investigate if the established theory concerning corrosion calculations and electrochemical behavior of carbon is valid when steel is exposed to AC in an electrolyte consisting of 3,5 wt% NaCl and distilled water. The experimental work was divided in two main parts. The first part concerned corrosion testing, including weight loss measurements in stagnant conditions in combination with linear polarization resistance experiments. AC-current densities investigated was 0-, 50-, 75-, 100-, 150-, 220- and 500 A/m2. Polarization curves were produced on two weight loss samples, one exposed to 150 A/m2 and the other exposed to 220 A/m2, at the end of the weight loss experiments.From the corrosion testing it was found that the estimated corrosion current densities (icorr) from the weight loss experiments on samples exposed to AC-current densities below 500 A/m2, was in an approximate accordance with the icorr values estimated from LPR. At 500 A/m2 the measured corrosion rates and corresponding corrosion currents were slightly higher than the remainder. The higher corrosion rate measured from the samples exposed to 500 A/m2 is suggested related to a non-faradaic corrosion contribution. The suggested mechanism is a facilitation of grain boundary corrosion at high AC-current densities leading to the loss of grains. This being a non-faradaic corrosion contribution it is not possible to measure with LPR or polarization curves. The constant B [mV] from the Stern-Geary equation was estimated on basis of LPR measurements. The constant displayed a decreasing trend with increasing AC-current densities. This was explained by the lowering of anodic and cathodic tafel slopes with increasing AC-current densities. The polarization resistance (Rp - [Ω∙m2]) also showed a decreasing trend with increased AC-current densities. This was explained by the increased current response in the LPR measurements with increasing AC-current densities.The second part was intended to elucidate the effect of AC on electrochemical behavior of the carbon steel through producing polarization curves at different AC-current densities using a rotating electrode experimental setup. Alterations in corrosion current densities, cathodic tafel slopes, limiting current density of oxygen reduction and corrosion potentials on steel without AC and at current densities of 100-, 150-, 220- and 500 A/m2 are investigated during the electrochemical testing.  From the rotating electrode experiments no significant change in corrosion current was found with increasing AC-current densities. The potential range, in which limiting current of oxygen reduction (ilim) appeared, decreased with increasing AC-current densities. This decrease in ilim also affected the corrosion potentials (Ecorr). A decrease in the potential range of ilim leads to a more cathodic Ecorr. A particular observation was found at AC-current densities of 150 A/m2 were the effect of ilim seemed absent. The samples exposed to this AC-current density also attained the most cathodic corrosion potentials at approximately -850mVSCE which was between 200-400mV lower than the samples exposed to the remaining AC-current densities. Cathodic tafel slopes showed a decreasing trend with increasing AC-current density. Anodic rafel slopes were considered absent due to pitting above Ecorr.Pictures of the weight loss samples were captured in the SEM. It was found that the formation of pits occurred on all weight loss samples exposed to AC. On the samples without induced AC no sign of pitting was observed. Hence it was found that the corrosion attacks attained a more local character when AC-current was induced in the steel samples

Developing My Perspectives on Scaffolding and Problem-Based Learning: A Retrospective View

In this paper, I describe the iterative development of my perspectives on scaffolding and problem-based learning through interactions with other scholars and research. Such influences include doctoral experiences, funded projects, and exposures to research from a variety of traditions

Clinical Practice Guideline on Evaluating the Effectiveness of Venipuncture Arm Simulation

Venipuncture is an integral process in clinical care, and it has an indispensable role in diagnostics and determining therapeutic interventions. The process of phlebotomy has faced several challenges that have compromised patients’ safety. The risk of incorrect venipuncture, or preanalytical errors, leading to severe patient complications of hematoma and thrombosis calls for training using current, evidence-based practices. The goal of this project was to develop a clinical practice guideline (CPG) to determine the efficacy of venipuncture simulation training using an arm task trainer to enhance the phlebotomy skills of nurses. Based on the outcome, present, state, test model and Nightingale’s theory of nursing, in this project a CPG was developed that focused on enhancing venipuncture simulation and improving the practice in nursing to reduce analytical errors. A team of multidisciplinary experts reviewed the CPG using the Appraisal of Guidelines for Research and Evaluation Evaluative II tool. The findings, based on the tool’s six domains, showed the phlebotomy content experts’ evaluations of the CPG’s scope and purpose, stakeholder involvement, rigor of development, and clarity. The results indicated that the CPG generally had room for improvement, with growth opportunities regarding information on the rigor of development, the clarity of presentation, applicability, and editorial independence. The quality domain scores ranged between 31% to 64% with a mean domain score of 52.1%. The CPG was rated as needing some refinement, with 100% of the expert panelists recommending use of the guideline with modification. Application of the evidence-based practice of using the CPG has the potential to improve patient outcomes, which is a positive social change

Instructional Scaffolding in STEM Education: Strategies and Efficacy Evidence

science education; educational technology; learning and instructio

Implementation of a Conflict Mediation Program in an Elementary School

Schools are looking at how violence in the school contributes to students\u27 stress levels and how it interferes with the academic abilities and performance of students. If schools are to be orderly and peaceful places in which high quality education can take place, students must learn to manage conflicts constructively. Studies show that conflict mediation plays a role in creating an environment where students regulate their own behavior in regards to conflict in school. This research study surveyed students about their attitudes and opinions towards conflict mediation at Beaver Lake Elementary School. This study also evaluated whether staff to student disciplinary contacts decreased after the implementation of the conflict mediation program

FRD characterization in large-scale for FOCCoS of Prime Focus Spectrograph for Subaru telescope

The focal ratio degradation effects on optical fibers, technically referred to as FRD, has been the subject of intense studies since the beginning of the use of optical fibers in the construction of instruments applied in astronomy. A number of studies attempt to relate FRD to light loss in the optical system and other studies attempt to qualify and quantify FRD as a function of the stress induced during assembly of the structures supporting the ends of the optical fibers. In this work, we present a large-scale study to characterize FRD in all the fibers that make up the cables of the FOCCoS, Fiber Optical Cable and Connectors System project. FOCCoS, has the main function of capturing the direct light from the focal plane of Subaru Telescope using 2400 optical fibers, each one with a microlens in its tip, and conducting this light through a route containing connectors to a set of four spectrographs. The optical fiber cable is divided in 3 different segments called Cable A, Cable B and Cable C. Multi-fibers connectors assure precise connection among all optical fibers of the segments, providing flexibility for instrument changes. Our study provides procedures and methods to analyze the effects of FRD on all cable segments for each type of termination involved. Special attention is devoted to the understanding of how angular deviations between the input surface of the fiber and the test beam can significantly influence the calculation of FRD in optical fibers