A Longitudinal Study of Engineering Student Performance and Retention. V. Comparisons with Traditionally-Taught Students

In a longitudinal study at North Carolina State University, a cohort of students took five chemical engineering courses taught by the same instructor in five consecutive semesters. The courses made extensive use of active and cooperative learning and a variety of other techniques designed to address a broad spectrum of learning styles. Previous reports on the study summarized the instructional methods used in the experimental course sequence, described the performance of the cohort in the introductory chemical engineering course, and examined performance and attitude differences between students from rural and urban backgrounds and between male and female students.1–4 This paper compares outcomes for the experimental cohort with outcomes for students in a traditionally‐taught comparison group. The experimental group outperformed the comparison group on a number of measures, including retention and graduation in chemical engineering, and many more of the graduates in this group chose to pursue advanced study in the field. Since the experimental instructional model did not require small classes (the smallest of the experimental classes had 90 students) or specially equipped classrooms, it should be adaptable to any engineering curriculum at any institution

The Effects of Personality Type on Engineering Student Performance and Attitudes

The Myers‐Briggs Type Indicator® (MBTI) was administered to a group of 116 students taking the introductory chemical engineering course at North Carolina State University. That course and four subsequent chemical engineering courses were taught in a manner that emphasized active and cooperative learning and inductive presentation of course material. Type differences in various academic performance measures and attitudes were noted as the students progressed through the curriculum. The observations were generally consistent with the predictions of type theory, and the experimental instructional approach appeared to improve the performance of MBTI types (extraverts, sensors, and feelers) found in previous studies to be disadvantaged in the engineering curriculum. The conclusion is that the MBTI is a useful tool for helping engineering instructors and advisors to understand their students and to design instruction that can benefit all of them

Lifting fish across barriers with the Tube Fishway: lessons from the laboratory

To transfer fish across barriers, fishways are commonly used. A multidisciplinary research team from UNSW Sydney, has made important progress on the operation of a new type of fishway, the Tube Fishway, under controlled conditions in the laboratory. Research has shown that fish can be successfully attracted into the Tube Fishway's transfer chamber, while an innovative lifting mechanism based upon an unsteady surge, has been introduced to avoid the use of a mechanical pump. Using this lifting mechanism, tests with juvenile Australian bass (Percalates novemaculeata) and silver perch (Bidyanus bidyanus) have shown that fish can be safely lifted in Tube Fishways with heights of 4 and 8 m. Replacing live fish with a neutrally buoyant sensor packet, has provided important guidance on the pressures and accelerations that fish would experience during operation of the Tube Fishway. Trials with an automated Tube Fishway have demonstrated the fully automated operation of the Tube Fishway paving the way for upcoming field installations of Tube Fishways. Important lessons from the laboratory experiments are discussed and future research needs addressed

Proof of concept for an innovative pump fishway design to move fish upstream over dams

Reversing worldwide declines in freshwater fish while making sustainable use of water resources will require effective and economical fishways to restore fish migrations. Mitigation of barrier effects at dams and weirs is too often impeded by poor fishway performance and high costs, so that many fish migrations continue to be obstructed. Improved and less-costly designs are urgently needed. Our innovative pump fishway concept combines fish-behaviour insights, proved fishways techniques and aquaculture’s pumping methods for safe upstream transport of living fish. We ran a series of experimental trials using several scale-model fishway designs with young, hatchery-bred fish. Our horizontal-cylinder design successfully combined volitional-passage functions of existing fishways with non-volitional transport in a conduit carrying pumped water. Several key principles of fish behaviour in fishways led to design improvements: disturbed fish often seek refuge at depth; fishes’ escape reactions strongly motivate swimming into flows; and curved structures aid passage by reducing delays. Replicated trials finally produced an average of 98% successful passage, within brief cycling periods. The pump fishway concept offers potential for effective upstream fish passage at new and existing sites \u3e~2m high, with low construction and maintenance costs and highly adaptable operation in variable flow regimes. Development beyond the concept-trial phase is now a priority

Redescription of Pinnixa arenicola Rathbun, 1922 (Decapoda: Brachyura: Pinnotheridae), with new observations on its range and host

Abstract.-Pinnixa arenicola is redescribed and illustrated on the basis of new collections and reexamined type material. Its occurrence in the burrows of Upogebia vasquezi Ngoc-Ho is reported, along with range extensions that include Florida, Puerto Rico, Aruba, and the Cayman Islands. New collections represent the first reports of P. arenicola since original discoveries in Curaçao and suggest a potentially wide distribution of the species in the tropical western Atlantic. Following publication of the unillustrated original description for the holotype male, females were also noted to occur in Curaçao, but illustrations with limited detail were provided by Rathbun for only the male holotype specimen. Prior to our work, no illustrations have depicted female morphology, unique male gonopods, or some pereopod features of potential value in defining phylogenetic relationships

Non-Equilibrium Large N Yukawa Dynamics: marching through the Landau pole

The non-equilibrium dynamics of a Yukawa theory with N fermions coupled to a scalar field is studied in the large N limit with the goal of comparing the dynamics predicted from the renormalization group improved effective potential to that obtained including the fermionic backreaction. The effective potential is of the Coleman-Weinberg type. Its renormalization group improvement is unbounded from below and features a Landau pole. When viewed self-consistently, the initial time singularity does not arise. The different regimes of the dynamics of the fully renormalized theory are studied both analytically and numerically. Despite the existence of a Landau pole in the model, the dynamics of the mean field is smooth as it passes the location of the pole. This is a consequence of a remarkable cancellation between the effective potential and the dynamical chiral condensate. The asymptotic evolution is effectively described by a quartic upright effective potential. In all regimes, profuse particle production results in the formation of a dense fermionic plasma with occupation numbers nearly saturated up to a scale of the order of the mean field. This can be interpreted as a chemical potential. We discuss the implications of these results for cosmological preheating.Comment: 36 pages, 14 figures, LaTeX, submitted to Physical Review

Conformal Orbifold Partition Functions from Topologically Massive Gauge Theory

We continue the development of the topological membrane approach to open and unoriented string theories. We study orbifolds of topologically massive gauge theory defined on the geometry $[0,1]\times\Sigma$, where $\Sigma$ is a generic compact Riemann surface. The orbifold operations are constructed by gauging the discrete symmetries of the bulk three-dimensional field theory. Multi-loop bosonic string vacuum amplitudes are thereby computed as bulk correlation functions of the gauge theory. It is shown that the three-dimensional correlators naturally reproduce twisted and untwisted sectors in the case of closed worldsheet orbifolds, and Neumann and Dirichlet boundary conditions in the case of open ones. The bulk wavefunctions are used to explicitly construct the characters of the underlying extended Kac-Moody group for arbitrary genus. The correlators for both the original theory and its orbifolds give the expected modular invariant statistical sums over the characters.Comment: 47 pages LaTeX, 3 figures, uses amsfonts and epsfig; v2: Typos corrected, reference added, clarifying comments on modular invariance inserted; v3: Further comments on modular invariance added; to be published in JHE

Tuning Locked Inflation: Supergravity versus Phenomenology

We analyze the cosmological consequences of locked inflation, a model recently proposed by Dvali and Kachru that can produce significant amounts of inflation without requiring slow-roll. We pay particular attention to the end of inflation in this model, showing that a secondary phase of saddle inflation can follow the locked inflationary era. However, this subsequent period of inflation results in a strongly scale dependent spectrum that can lead to massive black hole formation in the primordial universe. Avoiding this disastrous outcome puts strong constraints on the parameter space open to models of locked inflation.Comment: 7 pages, 2 figure