From Pentagon to Heptagon: A Discovery on the Generation of the Regular Heptagon from the Equilateral Triangle and Pentagon

Geometer Marcus the Marinite presents a construction for the heptagon that is within an incredibly small percent deviation from the ideal. The relationship between the incircle and excircle of the regular pentagon is the key to this construction, and their ratio is 2 : ϕ. In other words, the golden section plays the critical role in the establishment of this extremely closeto-ideal heptagon construction.     

Researching haptics in higher education: The complexity of developing haptics virtual learning systems and evaluating its impact on students’ learning

hapTEL, an interdisciplinary project funded by two UK research councils from 2007 to 2011, involves a large interdisciplinary team (with undergraduate and post-graduate student participants) which has been developing and evaluating a virtual learning system within an HE healthcare education setting, working on three overlapping strands. Strand 1 involves the technical development and evaluation of the hapTEL workstation which simulates clinical conditions for dental training including haptics (sense of touch). Strand 2 involves examining the traditional undergraduate curriculum and how this could benefit from the use of haptics. Strand 3 is concerned with the educational evaluation of the impact of the work carried out within Strands 1 and 2. Two theoretical frameworks (Entwistle, (1987) and Webb and Cox (2004)) have been used to identify as many factors as possible which could affect the impact of Technology Enhanced Learning (TEL) on the quality of the learning achieved. These frameworks have formed a foundation for measuring the impact of TEL on curriculum change, teachers’ pedagogical practices, students’ learning and on institutional practices. A range of quantitative and qualitative methods were designed, piloted and evaluated in order to measure the impact of TEL on teaching and learning; and to have a rich and robust data set which also addresses the variables in the frameworks. The results from using these frameworks show that institutional and departmental factors should be considered when evaluating the impact of TEL in higher education and that these had a major influence on the design and curriculum integration of the hapTEL systems. We have also shown that by involving the end users from the beginning enabled not only an enhancement of the students’ learning experiences but also a modification to the traditional curriculum itself and the successful integration of TEL within a very traditional undergraduate higher education dental curriculum. The conclusions from this paper confirm earlier reviews of researching TEL that technology integration is extremely complex and the related research requires a comprehensive approach of both quantitative and qualitative methods if one is to take account of the range of variables identified by theoretical frameworks. Finally, repeating the range of empirical investigations for a second year enables researchers to validate the effectiveness of the methods used in the initial year and thereby maximise the reliability and generalisability of the research outcomes.     

A Simple Bioconjugate Attachment Protocol for Use in Single Molecule Force Spectroscopy Experiments Based on Mixed Self-Assembled Monolayers

Single molecule force spectroscopy is a technique that can be used to probe the interaction force between individual biomolecular species. We focus our attention on the tip and sample coupling chemistry, which is crucial to these experiments. We utilised a novel approach of mixed self-assembled monolayers of alkanethiols in conjunction with a heterobifunctional crosslinker. The effectiveness of the protocol is demonstrated by probing the biotin-avidin interaction. We measured unbinding forces comparable to previously reported values measured at similar loading rates. Specificity tests also demonstrated a significant decrease in recognition after blocking with free avidin.     

Atomic Force Microscope Cantilever Flexural Stiffness Calibration: Toward a Standard Traceable Method

The evolution of the atomic force microscope into a useful tool for measuring mechanical properties of surfaces at the nanoscale has spurred the need for more precise and accurate methods for calibrating the spring constants of test cantilevers. Groups within international standards organizations such as the International Organization for Standardization and the Versailles Project on Advanced Materials and Standards (VAMAS) are conducting studies to determine which methods are best suited for these calibrations and to try to improve the reproducibility and accuracy of these measurements among different laboratories. This paper expands on a recent mini round robin within VAMAS Technical Working Area 29 to measure the spring constant of a single batch of triangular silicon nitride cantilevers sent to three international collaborators. Calibration techniques included reference cantilever, added mass, and two forms of thermal methods. Results are compared to measurements traceable to the International System of Units provided by an electrostatic force balance. A series of guidelines are also discussed for procedures that can improve the running of round robins in atomic force microscopy.     

Analyzing the Next Generation Software Defined Radio for Future Architectures

Commercial and research work in the field of software defined radio (SDR) has produced designs which have been able to deliver the efficiency and computational power needed to process 3G wireless technologies. Though efficient 3G processing has been achieved by these designs, next generation 4G SDR technology requires 10–1000x more computational performance but limits the power budget increase to 2–5x. In this paper, we present a breakdown of the major 4G kernels and analyze two methods of increasing performance and reducing power consumption. Specifically, we consider the effect of SIMD width and reduction in number of register file accesses on the performance and energy consumption of a SDR architecture, SODA. We show that by increasing SIMD width we can gain almost 2–8x performance increase while increasing total energy used by 1–2x for different SIMD widths. We also show that by reducing SIMD register accesses we can reduce the total energy used by 5–20% for the 4G kernels.     

The Reluctant Czech Master

Abstract

The talented and enigmatic Jaroslav Rossler (1902–90) made progressive works for only about fifteen years, between 1919 and 1935. Some regard him as the quintessential Czech modernist photo-artist because his work so thoroughly reflects many of the canonical movements of the early twentieth century: abstraction, Cubism, Futurism, Constructivism, Poetism, Functionalism, and so on. His work has been long overlooked; the first real retrospective of his art occurred only three years ago, at the Museum of Decorative Arts, Prague. That exhibition served as the base of information for this handsomely produced monograph, which is by far the most thorough treatment of Rössler to date.     

A simple frequency-domain algorithm for early detection of damaged gear teeth

Fixed transducers often are used to monitor meshing gear pairs in order to detect tooth damage. A simple frequency-domain damage-detection algorithm is suggested for very early detection of such damage. Ratios of rotational-harmonic amplitudes computed from before and after potential damage are utilized to eliminate effects of transducer and structural-path-caused amplitude changes between tooth-meshing location and transducer output, to minimize attenuating effects of multiple-tooth contact, and thereby, to approximately equally weight rotational-harmonic amplitudes over a wide range of harmonics. Statistical averaging of absolute values of logarithmic ratios of rotational-harmonic amplitudes is used to minimize fluctuations caused by multiple-tooth contact and manufacturing errors on the subject gear. Synchronous averaging is employed to minimize effects of noise and manufacturing errors on the mating gear. Time-windowing tailored to contact ratios of mating gears is utilized to isolate individual tooth locations. Resultant windowing effects on availability of useful rotational harmonics are analyzed. Application of the algorithm to detection of seeded bending-fatigue faults on a planetary ring-gear tooth indicates that successful detections were achieved.     

Mixtures of poly(vinyl chloride) and copolyesters based on ε‐caprolactone and L‐lactide: Miscibility,thermal stability,and weathering resistance

Properties of the blends of Poly(vinyl chloride) (PVC) and poly(ε‐caprolactone) (PCLO) and copolyesters based on ε‐caprolactone and L‐lactide (LLA) prepared by rolling were studied. Incorporating the LLA units into the structure of PCLO the content of the crystalline phase was controlled. Miscibility of the blends was assessed using DMA, and basic mechanical properties were correlated with the type and content of the polymer plasticizer. The PVC blends containing up to 20 wt parts polyesters were miscible. The presence of the LLA units in the copolyester influenced negatively the thermal stability. On the other hand even small content of copolyester in the blend enhanced the resistivity against aging. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

A survey of clinical psychology training in Canadian federal corrections: Implications for psychologist recruitment and retention.

Although survey results seem to indicate an abundant interest among Canadian psychology graduate students in pursuing training in criminal justice psychology, the recruitment and retention of psychologists in the Correctional Service of Canada (CSC) has been of some concern. The present study is a 2008 survey of sites within CSC that provide opportunities for clinical psychology training with offender clientele. Survey findings demonstrated that a broad range of clinical psychology training opportunities were available across 16 sites. The most frequently cited barrier to providing training was lack of time by prospective trainers, and sites reported retaining relatively few of their trainees for subsequent psychologist positions. Information was also obtained regarding vacant psychologist positions across CSC regions. In light of survey findings, substantive discussion is devoted toward the issues of psychologist recruitment and retention in Canadian federal corrections, including a discussion of both potential and existing training initiatives. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Modulation Excitation X-Ray Absorption Spectroscopy to Probe Surface Species on Heterogeneous Catalysts

The advantages and open questions of the combination of modulation excitation spectroscopy and phase sensitive detection (PSD) with X-ray absorption spectroscopy (XAS) for the analysis of heterogeneous catalysts at work are reviewed. The characteristic spectral signatures of two different edges (Pd K and Pt L₃) are described in relation to the red-ox chemistry of Pd/Al₂O₃ and Pt/Al₂O₃ with respect to NO reduction by CO and CO oxidation, respectively. Both examples demonstrate that PSD makes XAS sensitive to potentially active species for the catalytic reaction.