Barker Central School District and Barker Central School Support Staff

In the matter of the fact-finding between the Barker Central School District, employer, and the Barker Central School Support Staff, union. PERB case no. M2009-035

Genesee, County of and The Civil Service Employees Association

In the Matter of the Fact-Finding between The County of Genesee, New York and The Civil Service Employees Association. PERB Case No. M2008-249. Michael S. Lewandowski, Fact Finder

Representational differences in how students compare measurements

Measurement uncertainty plays a critical role in the process of experimental physics. It is useful to be able to assess student proficiency around the topic to iteratively improve instruction and student learning. For the topic of measurement uncertainty, we developed an assessment tool called the Survey of Physics Reasoning on Uncertainty Concepts in Experiments (SPRUCE), which aims to assess students' knowledge, and use of, a variety of concepts related to measurement uncertainty. This assessment includes two isomorphic questions focused on comparing two measurements with uncertainty. One is presented numerically and the other pictorially. Despite the questions probing identical concepts, students answer them in different ways, indicating that they rely on distinct modes of representation to make sense of measurement uncertainty and comparisons. Specifically, students score much higher on the pictorially represented item, which suggests possible instructional changes to leverage students' use of representations while working with concepts of measurement uncertainty.Comment: 4 pages, 2 figures, to be published in PERC Conference Proceedings 202

Design and Evaluation of End-Effectors for Autonomous Sampling

Autonomous underwater vehicles are becoming increasingly prevalent, and their emergence will allow for the execution of previously unfeasible underwater missions. These missions include seeking naval mines, navigation and mapping of ocean features, and sampling on the ocean floor at extreme depths. One method to achieve this latter objective involves the attachment of a robotic manipulator to an underwater vehicle and use of the manipulator to collect specimens and deposit them in containers. This thesis focuses on the design and testing of an end-effector to be used on such a manipulator. End-effectors previously utilized in underwater robotics were evaluated during the conceptualization of the selected tool design. These evaluations in conjunction with manipulator interface requirements were used to produce the end-effector design that was constructed and subsequently tested. In addition, sample containers were designed and fabricated, and kinematics software used to determine sample container position, orientation, and quantity was developed

Numerical Investigation of Flow Distributions in Liquid Fuel Molten Salt Reactors

A computational fluid dynamics investigation was conducted to evaluate the thermal-hydraulic behavior within a molten salt nuclear core for a given heat generation profile. The entry length behavior, maximum temperature, and radial temperature gradient are investigated to provide insight as to the effective heat removal capabilities for two domains. The first flow geometry evaluated was a fully developed, 1D laminar flow in a cylindrical flow channel within a hexagonal graphite unit cell with internal heat generation in both the fluid and solid domains. This flow geometry had adiabatic boundary conditions imposed upon the outer wall of the graphite, and entry length behavior of the fluid was investigated to provide insight to the value of the effective heat transfer coefficient for a given coolant channel within a molten salt reactor core, as well as characterizing it as a function of height. An array of the hexagonal unit cell organized into a 60-degree wedge which represent a simplified molten salt reactor core region was next evaluated. The aim of this evaluation was that for a given heat generation profile, which was axially and radially dependent, by controlling the mass flow rate through each channel the radial temperature gradient and maximum temperature can be minimized, thus minimizing the thermal stresses. This minimization of the radial temperature gradient is also beneficial for neutronic evaluation, as the radial density distribution of the fuel salt is temperature dependent. Furthermore, the minimization of the maximum temperature in the reactor core is desired for both structural and neutronic purposes, as a significantly large thermal maximum could induce structural failure or a local perturbation of the neutron flux in that region due to temperature feedback effects and local density variation. It was found that due to the internal heat generation in the solid graphite domain, the maximum temperature was located in the graphite and the fuel salt acted as a coolant, rather than depositing heat into the graphite. The ideal mass flow rate distribution was found, and the combined entry length behavior of a channel in that case was evaluated. Application of this methodology provides key insight into the design specifications needed for a flow distributor which could be present in the lower plenum region

Couplet scoring for research based assessment instruments

Contemporary content-focused research-based assessment instruments typically use instrument items (i.e., questions) as the unit of assessment for instrument scoring, reporting, and validation. However, traditional item-based scoring has a number of limitations, including several arising from the use of the common assessment development conventions of single-construct items, unidimensionality, and single-correct-answer items. Couplet scoring, introduced in this paper, employs the couplet as an alternative unit of assessment, where a couplet is essentially an item viewed and scored through the lens of a specific assessment objective (AO). With couplet scoring, a single item may have more than one AO and therefore more than one couplet. In this paper, we outline the limitations of traditional item scoring, introduce couplet scoring and discuss its affordances (especially as they relate to limitations of item scoring), and use a recently developed content RBAI to ground our discussion.Comment: 13 pages, 2 figure

Preparing for the quantum revolution -- what is the role of higher education?

Quantum sensing, quantum networking and communication, and quantum computing have attracted significant attention recently, as these quantum technologies offer significant advantages over existing technologies. In order to accelerate the commercialization of these quantum technologies the workforce must be equipped with the necessary skills. Through a qualitative study of the quantum industry, in a series of interviews with 21 U.S. companies carried out in Fall 2019, we describe the types of activities being carried out in the quantum industry, profile the types of jobs that exist, and describe the skills valued across the quantum industry, as well as in each type of job. The current routes into the quantum industry are detailed, providing a picture of the current role of higher education in training the quantum workforce. Finally, we present the training and hiring challenges the quantum industry is facing and how higher education may optimize the important role it is currently playing

Advanced Stirling Radioisotope Generator Engineering Unit 2 Anomaly Investigation

The Advanced Stirling Radioisotope Generator (ASRG) Engineering Unit 2 (EU2) is the highest fidelity electrically heated Stirling radioisotope generator built to date. NASA Glenn Research Center completed the assembly of the ASRG EU2 in September 2014 using hardware from the now cancelled ASRG flight development project. The ASRG EU2 integrated the first pair of Sunpower's Advanced Stirling Convertors (ASCE3 #1 and #2) in an aluminum generator housing with Lockheed Martin's (LM's) Engineering Development Unit (EDU) 4 controller. After just 179 hr of EU2 generator operation, the first power fluctuation occurred on ASCE3 #1. The first power fluctuation occurred 175 hr later on ASCE3 #2. Over time, the power fluctuations became more frequent on both convertors and larger in magnitude. Eventually the EU2 was shut down in January 2015. An anomaly investigation was chartered to determine root cause of the power fluctuations and other anomalous observations. A team with members from Glenn, Sunpower, and LM conducted a thorough investigation of the EU2 anomalies. Findings from the EU2 disassembly identified proximate causes of the anomalous observations. Discussion of the team's assessment of the primary possible failure theories, root cause, and conclusions is provided. Recommendations are made for future Stirling generator development to address the findings from the anomaly investigation. Additional findings from the investigation are also discussed