Blended Laboratories for Joining Technology

Laboratory training is an essential part of most Engineering Education programs and amplified by the Covid-19 crisis, educational institutions are increasingly exploring blended and online laboratories as an alternative or complement to pure on-side learning environments. In this paper, we report on the (re-) design, implementation and evaluation of a blended laboratory concept in joining technology. The laboratory consists of three interlinked pillars and builds conceptually on the flipped classroom approach. We evaluate student learning and satisfaction as well as teacher experiences in the new learning design based on student evaluations and performance data as well as teacher reflections. The results show that the new laboratory improved the average grade of students by 12% compared to the traditional set-up, which we attribute to the increase in active learning. Students also report high satisfaction with the new format and appreciate the flexibility and accessibility of the online learning materials. Qualitative analysis indicates, however, that successful participation in the flipped format is coupled to high degree of self-regulated learning skills. Further, teachers partly had difficulties to ensure active participation in the synchronous online sessions. Despite these issues, we conclude that the presented flipped laboratory concept is an excellent format to combine the advantages of online learning with the hands-on experience of physical laboratory work. By utilizing the benefits of online learning, this format reduces the time students spend passively listening to lectures and more than doubles the time spent on active learning and practice

A cable-suspended intelligent crane assist device for the intuitive manipulation of large payloads

This paper presents a cable-suspended crane system to assist operators in moving and lifting large payloads. The main objective of this work is to develop a simple and reliable system to help operators in industry to be more productive while preventing injuries. The system is based on the development of a precise and reliable cable angle sensor and a complete dynamic model of the system. Adaptive horizontal and vertical controllers designed for direct physical human-robot interaction are then proposed. Different techniques are then proposed to estimate the payload acceleration in order to increase the controller performances. Finally, experiments performed on a full-scale industrial system are presented

An articulated assistive robot for intuitive hands-on-payload manipulation

This paper presents an intelligent assistive robot designed to help operators in lifting and moving large payloads through direct physical contact (hands-on-payload mode). The mechanical design of the robot is first presented. Although its kinematics are similar to that of a cable-suspended system, the proposed mechanism is based on articulated linkages, thereby allowing the payload to be offset from the rail support on which it is suspended. A dynamic model of the robot is then developed. It is shown that a simplified dynamic model can be obtained using geometric assumptions. Based on the simplified dynamic model, a controller is then presented that handles the physical human-robot interaction and that provides the operator with an intuitive direct control of the payload. Experimental validation on a full-scale prototype is presented in order to demonstrate the effectiveness of the proposed robot and controller

Manganese pigmented anodized copper as solar selective absorber

The study concerns the optical and structural properties of layers obtained by a new efficient surface treatment totally free of chromium species. The process is made up of an anodic oxidation of copper in an alkaline solution followed by an alkaline potassium permanganate dipping post-treatment. Coatings, obtained at the lab and pilot scales, are stable up to 220 °C in air and vacuum, present low emissivity (0.14 at 70 °C) and high solar absorptivity (0.96), i.e. a suitable thermal efficiency (0.84 at 70 °C)

The Environmental Influence on the Evolution of Local Galaxies

The results of an Halpha photometric survey of 30 dwarf galaxies of various morphologies in the Centaurus A and Sculptor groups are presented. Of these 30, emission was detected in 13: eight are of late-type, two are early-type and three are of mixed-morphology. The typical flux detection limit of 2e-16 erg s-1 cm-2, translates into a Star Formation Rate (SFR) detection limit of 4e-6 M_sol yr-1 . In the light of these results, the morphology-density relation is reexamined: It is shown that, despite a number of unaccounted parameters, there are significant correlations between the factors determining the morphological type of a galaxy and its environment. Dwarf galaxies in high density regions have lower current SFR and lower neutral gas content than their low density counterparts, confirming earlier results from the Local Group and other denser environments. The effect of environment is also seen in the timescale formed from the ratio of blue luminosity to current SFR - dwarfs in higher density environments have larger values, indicating relatively higher past average SFR. The influence of environment extends very far and no dwarfs from our sample can be identified as 'field' objects.Comment: 23 pages, 9 figures, accepted in A

How much is enough? Minimal responses of water quality and stream biota to partial retrofit stormwater management in a suburban neighborhood

Decentralized stormwater management approaches (e.g., biofiltration swales, pervious pavement, green roofs, rain gardens) that capture, detain, infiltrate, and filter runoff are now commonly used to minimize the impacts of stormwater runoff from impervious surfaces on aquatic ecosystems. However, there is little research on the effectiveness of retrofit, parcel-scale stormwater management practices for improving downstream aquatic ecosystem health. A reverse auction was used to encourage homeowners to mitigate stormwater on their property within the suburban, 1.8 km2 Shepherd Creek catchment in Cincinnati, Ohio (USA). In 2007–2008, 165 rain barrels and 81 rain gardens were installed on 30% of the properties in four experimental (treatment) subcatchments, and two additional subcatchments were maintained as controls. At the base of the subcatchments, we sampled monthly baseflow water quality, and seasonal (5×/year) physical habitat, periphyton assemblages, and macroinvertebrate assemblages in the streams for the three years before and after treatment implementation. Given the minor reductions in directly connected impervious area from the rain barrel installations (11.6% to 10.4% in the most impaired subcatchment) and high total impervious levels (13.1% to 19.9% in experimental subcatchments), we expected minor or no responses of water quality and biota to stormwater management. There were trends of increased conductivity, iron, and sulfate for control sites, but no such contemporaneous trends for experimental sites. The minor effects of treatment on streamflow volume and water quality did not translate into changes in biotic health, and the few periphyton and macroinvertebrate responses could be explained by factors not associated with the treatment (e.g., vegetation clearing, drought conditions). Improvement of overall stream health is unlikely without additional treatment of major impervious surfaces (including roads, apartment buildings, and parking lots). Further research is needed to define the minimum effect threshold and restoration trajectories for retrofitting catchments to improve the health of stream ecosystems

Xenopus staufen2 is required for anterior endodermal organ formation

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in genesis 50 (2012): 251-259, doi:10.1002/dvg.22000.Defining the regulatory molecular networks involved in patterning the developing anterior endoderm is essential to understanding how the pancreas, liver, stomach and duodenum are discretely specified from each other. In this study, we analyzed the expression and function of the double-stranded RNA-binding protein Staufen2 in Xenopus laevis endoderm. We found that staufen2 was broadly expressed within the developing endoderm beginning at gastrulation becoming localized to the anterior endoderm at later stages. Through morpholino-mediated knockdown, we demonstrate that Staufen2 function is required for proper formation of the stomach, liver and pancreas. We define that its function is required during gastrulation for proper patterning of the dorsal-ventral axis and that it acts to regulate expression of BMP signaling components.This work was supported by grants from the National Institutes of Health (DK077197) to M.E.H. and from the Canadian Institute of Health Research (Frederick Banting and Charles Best Canada Graduate Scholarships - Doctoral Awards) to C.K.B

Mouse Ten-m/Odz Is a New Family of Dimeric Type II Transmembrane Proteins Expressed in Many Tissues

The Drosophila gene ten-m/odz is the only pair rule gene identified to date which is not a transcription factor. In an attempt to analyze the structure and the function of ten-m/odz in mouse, we isolated four murine ten-m cDNAs which code for proteins of 2,700–2,800 amino acids. All four proteins (Ten-m1–4) lack signal peptides at the NH2 terminus, but contain a short hydrophobic domain characteristic of transmembrane proteins, 300–400 amino acids after the NH2 terminus. About 200 amino acids COOH-terminal to this hydrophobic region are eight consecutive EGF-like domains

Impact of UV Radiation from Giant Spirals on the Evolution of Dwarf Galaxies

We show that ultraviolet radiation, with wavelengths shorter than 2000 A, escaping from the disks of giant spirals could be one of the principal factors affecting the evolution of low mass satellite galaxies. We demonstrate, using a semi-qualitative model, that the Lyman continuum part of the radiation field can lead to ionization of the ISM of the dwarf galaxies through the process of photoevaporation, making the ISM virtually unobservable. The FUV part (912 < lambda < 2000 A) is shown to dominate over the internal sources of radiation for most of the Galactic dwarf spheroidals. The proposed environmental factor could be at least partially responsible for the bifurcation of the low mass proto-galaxies into two sequences - dwarf irregulars and dwarf spheroidals. We discuss many peculiarities of the Local Group early-type dwarfs which can be accounted for by the impact of the UV radiation from the host spiral galaxy (Milky Way or M31).Comment: 15 pages, 12 figures. Accepted for publication in MNRAS. More consistent photoionization model is used in Sect. 2. All main results stay unchange