Performance of Graduate Students at Identifying Introductory Physics Students' Difficulties Related to Kinematics Graphs

The Test of Understanding Graphs in Kinematics (TUG-K) is a multiple choice test developed by Beichner to assess students' understanding of kinematics graphs. Many of the items on the TUG-K have strong distractor choices which correspond to introductory students' common difficulties with kinematics graphs. Instruction is unlikely to be effective if instructors do not know these common difficulties and take them into account in their instructional design. We evaluate the performance of first year physics graduate students at identifying introductory students' common difficulties related to kinematics graphs. In particular, for each item on the TUG-K, the graduate students were asked to identify which incorrect answer choice they thought would be most commonly selected by introductory physics students if they did not know the correct answer after instruction in relevant concepts. We used the introductory student data from Beichner's original paper to assess graduate students' knowledge of introductory students' difficulties. Furthermore, we selected the four questions on the TUG-K on which the graduate student performance was the poorest for a more detailed analysis which included think-aloud interviews. We present results which can partly account for the poor graduate student performance on these questions and also inform instruction in professional development courses.Comment: Peer reviewed conference proceedings 4 page

Exploring Pedagogical Content Knowledge of Teaching Assistants Using the Test of Understanding Graphs in Kinematics

The Test of Understanding Graphs in Kinematics (TUG-K) is a multiple choice test developed by Beichner in 1994 to assess students' understanding of kinematics graphs. Many of the items on the TUG-K have strong distractor choices which correspond to students' common difficulties with kinematics graphs. Instruction is unlikely to be effective if instructors do not know the common difficulties of introductory physics students and explicitly take them into account in their instructional design. We evaluate the pedagogical content knowledge of first year physics graduate students enrolled in a teaching assistant (TA) training course related to topics covered in the TUG-K. In particular, for each item on the TUG-K, the graduate students were asked to identify which incorrect answer choice they thought would be most commonly selected by introductory physics students if they did not know the correct answer after instruction in relevant concepts. We used the graduate student data and the data from Beichner's original paper for introductory physics students to assess the relevant pedagogical content knowledge (PCK) of the graduate students. We find that, although the graduate students, on average, performed better than random guessing at identifying introductory student difficulties on the TUG-K, they did not identify many common difficulties that introductory students have with graphs in kinematics even after traditional instruction. In addition, we find that the ability of graduate students to identify the difficulties of introductory students is context dependent

Can students apply the concept of "which-path" information learned in the context of Mach Zehnder Interferometer to the double-slit experiment?

The ability to use concepts learned in one context to solve problems in a different context (i.e., transfer of learning) is a hallmark of expertise in physics. The majority of the studies on transfer of learning in physics have focused on introductory students. However, compared to advanced students, introductory students have significantly less prior relevant knowledge and skills which may be crucial for promoting effective transfer. Here, we examine upper-level undergraduate and graduate students' ability to transfer their learning about the concept of "which-path" information and its relation to whether or not interference is observed from the context of the Mach Zehnder Interferometer (MZI) to a new context of the double-slit experiment (DSE). Students worked through a tutorial on the MZI in which they learned to use the concept of "which-path" information to reason about interference of single photons when polarizers with various orientations are placed in one or both paths of the MZI. After working on the MZI tutorial, students were asked similar questions in the isomorphic context of the DSE before any instruction about the DSE and we examined the extent to which transfer of learning about "which-path" information occurred from the MZI to the DSE context. We find evidence suggesting that positive transfer of learning from the MZI to the DSE occurred despite the lack of an instructional intervention designed to help students recognize the similarity between the two contexts. The effectiveness of the MZI tutorial in promoting positive transfer of learning from one context to another in quantum mechanics sheds light on the expertise of the advanced physics students. Instructors of advanced physics courses can take advantage of the findings presented here which shows the difference between introductory and advanced students' ability to transfer from one context to another.Comment: 14 pages, 7 figure

Investigating transfer of learning in advanced quantum mechanics

Research suggests that students often have difficulty transferring their learning from one context to another. We examine upper-level undergraduate and graduate students' facility with questions about the interference pattern in the double-slit experiment (DSE) with single photons and polarizers of various orientations placed in front of one or both slits. Before answering these types of questions, students had worked through a tutorial on the Mach-Zehnder Interferometer (MZI) in which they learned about interference of single photons when polarizers of various orientations are placed in the two paths of the MZI. After working on the MZI tutorial, students were asked similar questions in the isomorphic context of the DSE. We discuss the extent to which they were able to transfer what they learned in the context of the MZI to analogous problems in the isomorphic context of the DSE.Comment: 4 pages, 3 figure

Homogeneous catalysis of the accelerated carbonation of Portland cement

A mechanism proposed for the accelerated carbonation of Portland cement has shown how the reaction proceeds through gaseous, liquid and solid phases in 9 distinct sequential steps. The overall speed of reaction is thus determined by the slowest step, and we have found that solvation and hydration of CO2 in water is commonly the rate-limiting step in the carbonation process. The literature suggests that the speed of this step might possibly be increased by three different classes of chemical 'enhancers' of CO2 hydration: (1) inorganic oxy-anions such as hypochlorite (ClO– ) or sulphite (SO32–) which act as Lewis bases to CO2; (2) organic solutes which form anions at alkaline pH, such as sugars and polyhydric alcohols; or (3) amines and alkanolamines, which may exert catalytic action by producing carbamates with CO2 by either zwitterion formation or charge-transfer. This paper explores these options in detail, supporting theoretical predictions with precise measurement of the rate of CO2 uptake in a 'eudiometer', to determine whether such rates might be beneficially enhanced in the carbonation of hydraulic binders and wastes, or in CO2 capture by mineral sequestration

Grading Practices and Considerations of Graduate Students at the Beginning of their Teaching Assignment

Research shows that expert-like approaches to problem-solving can be promoted by encouraging students to explicate their thought processes and follow a prescribed problem-solving strategy. Since grading communicates instructors' expectations, teaching assistants' grading decisions play a crucial role in forming students' approaches to problem-solving in physics. We investigated the grading practices and considerations of 43 graduate teaching assistants (TAs). The TAs were asked to grade a set of specially designed student solutions and explain their grading decisions. We found that in a quiz context, a majority of TAs noticed but did not grade on solution features which promote expert-like approaches to problem-solving. In addition, TAs graded differently in quiz and homework contexts, partly because of how they considered time limitations in a quiz. Our findings can inform professional development programs for TAs

The internet, a possibility of development in Cluj-Napoca’s companies

The article shows the results of an inquiry done in a series of cluj napoca companies regarding the use of the internet for business purposes. From the questioned companies, 275 in number, more than 76% use the internet for business purposes. Thus, we can strongly say that the Cluj companies are “opened” to the newly developed network, being aware of the opportunities that this can offer. Many companies have understood that the internet is an exceptional resource of offering services to clients, they can show details about their products, activities, services, etc. if we consider the electronic commerce and virtual business, then the expending possibilities of the companies grow, making competitive advantages for the development strategies, being in a permanent change.Internet, companies, using, advantages