Improving spatial ability using a Web-based Virtual Environment (WbVE)

Spatial ability is one of the cognitive means used in problem solving activities particularly when manipulating and processing visuo-spatial information. With the increasing use of network communication, conventional teaching and learning has shifted towards the development of network environments, online learning, real-time interaction and high quality multi-user collaboration. This paper presents our experiment using a Web-based Virtual Environment (WbVE) that has improved a group of pre-service teachers' spatial ability understanding for teaching Engineering Drawing for secondary school subjects. The experiment is carried out in Universiti Pendidikan Sultan Idris (UPSI) comprising of 98 pre-service teachers taking the Computer Aided-Design (CAD) course. Selected subjects were pre-tested at the beginning of the semester with spatial tests focusing on mental rotation and spatial visualization to provide the baseline measurement. A desktop WbVE, which was employed and tested in the CAD laboratories to improve their spatial ability for five weeks of instructional treatment, will be demonstrated. Post-testing of spatial tests revealed significantly the overall spatial ability improvements as measured by the test scores. This paper concludes with a discussion on the impact of WbVE spatial learning that will be used as a precedent in the development of the VE teaching and learning prototypes for secondary school in Malaysia.     

A Well-Cultivated House

The project to design a villa in Mongolia in China provided Rafi Segal with an opportunity to rethink the relationship between the natural and the built, blurring the boundaries between the agricultural and the domestic. The house and rural landscape are unified through the main roof structure, a furrowed surface that resembles a ploughed field planted with crops and local flora. Copyright © 2010 John Wiley & Sons, Ltd.     

Transduction of cultured oligodendrocytes from normal and twitcher mice by a retroviral vector containing human galactocerebrosidase (GALC) cDNA

We examined in mice the effect of chronic diazepam treatment on the sensitivity to isoflurane, and that of repeated isoflurane exposure on the sensitivity to diazepam. Mice were divided into four groups: group 1, treated with diazepam, 10 mg/kg i.p. twice daily; group 2, vehicle-treated controls; group 3, exposed to 3% isoflurane for 25 min twice daily; and group 4, untreated controls. After 14 days the effect of the treatment was assessed. Twenty-four hours after the last 10 mg/kg diazepam treatment, groups 1 and 2 received diazepam, 5 mg/kg i.p., and were subjected to the horizontal wire test (HWT). All control mice but only 10% of the diazepam-treated mice failed the HWT. Groups 1 and 2 were then exposed to increasing concentrations of isoflurane. Diazepam-treated mice (group 1) lost the HWT at 0.7+/-0.7%, compared with 0.6+/-0.1% in controls (group 2) (P<0.001); the ED50 was 0.75% vs. 0.65%. Group 1 mice lost the righting reflex at 0.94+/-0.07% isoflurane vs. 0.87+/-0.06% in group 2 (P<0.01); the ED50 was 0.93% vs. 0.82%. Recovery time was 175+/-161 s in group 1 vs. 343+/-275 s in group 2 (P<0.02). Twenty-four hours after the last of the repeated exposures to isoflurane, we examined the responses of groups 3 and 4 to increasing concentrations of isoflurane. Mice in group 3 lost the righting reflex at 1.0+/-0.06% isoflurane vs. 0.9+/-0.04% in controls (group 4) (P<0.001); the ED50 was 0.96% vs. 0.85%. Recovery time was 113+/-124 s vs. 208+/-126 s in groups 3 and 4 (P<0.09). Diazepam, 3 mg/kg i.p. administered to groups 3 and 4, caused loss of the HWT reflex in 33% of group 3 mice and in 82% of controls (group 4) (P<0.001). It appears that prolonged exposure to both diazepam and isoflurane caused reduced sensitivity to each drug separately, as well as to the other drug. This finding may strengthen the theory that inhalational anesthetics may act via the same mechanism as the benzodiazepines.     

Dual-purpose semi-fragile watermark: Authentication and recovery of digital images

This paper presents a framework based on a single dual-purpose semi-fragile watermark to verify the integrity of digital image along with the recovery of distorted image. The watermark is correlated to the host image for detecting the collage attack and then embedded in their respective wavelet subbands. Unlike the conventional block-based approaches, this work has the ability to determine the unverified regions concisely. Huffman and BCH coding are utilized while generating the watermark. Integer DCT has been exploited as it can be highly compressed by Huffman coding as compared to the conventional DCT contents. The proposed technique exhibits the flexibility between imperceptibility, robustness, and capacity. In addition, integer wavelet transform has been used to reduce the computational complexity of the algorithm. Evaluation of experimental investigation shows the performance of dual-purpose semi-fragile watermark.     

Material Flow Visualization during Friction Surfacing

Metal flow behavior within friction surfaced coating was studied using tungsten powder as a marker. The results show that the top and bottom layers within the coating exhibit distinct flow patterns. The transport of material takes an involute path, and the material transfer starts from the advancing side of the coating to the retreating side and terminates at the center. The recirculation of material occurs at the retreating side of the coating.     

Block/Tower: A Vertical Landscape in Midtown Manhattan

Stan Allen and Rafi Segal are both independent New York-based practitioners and educators: Allen is Professor of Architecture at Princeton University, and Segal is Associate Professor of Architecture and Urbanism at the Massachusetts Institute of Technology (MIT). Here they collaborate on a high-density and flexible design strategy for Midtown Manhattan that is driven by ecological, social and spatial concerns rather than the usual commercial drivers of speculative development.     

Solvo-solid preparation of Zn3N2 hollow structures; their PL yellow emission and hydrogen absorption characteristics

Zinc nitride (Zn₃N₂) hollow structures with 10-25 μm size have been prepared by solvo-solid approach using aqueous ammonia treated Zn precursor at reaction temperature of 600 °C for reaction time of 240 min under ammonia gas flow. The structural, compositional and morphological characterizations of the as-obtained product were performed by XRD, EDS and SEM. Room temperature photoluminescence (PL) spectrum of zinc nitride hollow structures (ZNHSs) exhibited UV emission band at 384 nm and a defect related yellow emission band at 605 nm. The first ever studies on hydrogen absorption characteristics of ZNHSs performed at 373 K showed an absorption capacity of 1.29 wt.%. Growth mechanism proposed for the formation of ZNHSs is also discussed briefly.     

The Palmach History Museum,Tel Aviv

In 1928 the Austrian architect and engineer Franz Löwitsch (1894–1946) published the article ‘Sensation of Space and Modern Architecture’ in Imago , the psychoanalytical journal edited by Sigmund Freud. Based on Richard Semon's theories of Mneme, which Löwitsch connected to psychoanalytical theories, the prevalence of dissimilar sensations of space throughout the stages of the development of western architectural history is presupposed, and Löwitsch offered an explanation of how their symbolic meanings reflected psychological conditions of a particular time and culture.

By connecting Semon's theory with psychoanalytical deliberations that equip the inherited memory of spatial sensations with pleasurable or unpleasurable emotions, Löwitsch furthermore argued that spatial sensations produce spatial concepts, and that the dominating shapes and forms of the architecture of a time therefore reflect the dominance of a particular inherited sensation of space. The unifying psychological make-up of a populace thus leads to spatial concepts that form an architecture which reflects these concepts and contain symbols that possess ‘satisfying powers’ valued by the majority of people of that particular time and place.

But Löwitsch's theory speaks of more than a mere justification for the usefulness of psychoanalytic theory as a methodology for the humanities. Löwitsch contrasted his findings meticulously with Oswald Spengler's controversially critiqued book The Decline of the West , Karl Scheffler's The Spirit of the Gothic and Eckhart von Sydow's Primitive Art and Psychoanalysis . The discussion of these contemporaneous writings that essentially sought to find the driving forces for the development of styles helps in formulating Löwitsch's final hypothesis. Here, he proposes the emergence of an ‘energetic space’ in architecture, which is the prevalent sensation of space that he predicts to emerge in the near future. His ultimate aim was not to enter academic discourse but rather to provide a scientifically based explanation, with which the impact of space on the inhabitant can be measured, explained and utilised in architectural practice.     

Corrosion behavior of ZrO2-SiO2-Al2O3 refractories in lead silicate glass melts

High-temperature (1200-1350 °C) corrosion of fused-cast ZrO₂-Al₂O₃-SiO₂ (ZAS) refractory contacting lead silicate glass melt (LSG) containing 68.5 wt% PbO was investigated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), differential scanning calorimetry (DSC), x-ray diffraction (XRD), thickness measurement and Archimedes density measurement. ZAS durability was improved by baddeliyete content and deteriorated with open porosity proportion, corundum percentage and eutectic mixture presence. Diffusion of lead resulted in fusion-temperature lowering of the glassy layers embedded within the ZAS particles. Heating caused viscosity drop across the interface, loosening the inter-connected refractory particles and disrupted the crystalline particles residing adjacent to the refractory exterior. Among three ZAS refractories tested in this research, the most durable material was the one with the utmost baddeliyete amount, the least open porosity and the minimum eutectic mixture.