Kinematics with computer graphics

The impact which computer graphics can have on engineering education is illustrated in this paper by considering the subject area of kinematics. Details of the mathematical modeling needed to support the generation of motion curves and computer graphics simulation for kinematic analysis are given, and a comparison is made with the current popular methods of analysis. Several results of computer graphic displays are given to illustrate the wide variety of situations where computer graphics can add to the teaching and understanding of kinematics.     

Detection and enumeration of Campylobacter jejuni and Campylobacter coli by indirect impedimetry with an oxygen scavenging system

Six strains of Campylobacter jejuni and Campylobacter coli were shown to grow in a variety of media, but, with one exception, they were unable to produce sufficient change in the electrical properties of the medium to allow their detection by impedance monitoring. With the use of an indirect method based on absorption of evolved carbon dioxide and a medium containing the oxygen scavenger Oxyrase, all strains were detectable, and correlations between time to detection and the logarithm of the inoculum level were excellent. The level of interstrain variation was sufficiently low that all data could be consolidated into a single calibration curve (r = 0.987).     

CO2 hydrate composite for ocean carbon sequestration

Rapid CO2 hydrate formation was investigated with the objective of producing a negatively buoyant CO2-seawater mixture under high-pressure and low-temperature conditions, simulating direct CO2 injection at intermediate ocean depths of 1.0-1.3 km. A coflow reactor was developed to maximize CO2 hydrate production by injecting water droplets (e.g., approximately 267 microm average diameter) from a capillary tube into liquid CO2. The droplets were injected in the mixing zone of the reactor where CO2 hydrate formed at the surface of the water droplets. The water-encased hydrate particles aggregated in the liquid CO2, producing a paste-like composite containing CO2 hydrate, liquid CO2, and water phases. This composite was extruded into ambient water from the coflow reactor as a coherent cylindrical mass, approximately 6 mm in diameter, which broke into pieces 5-10 cm long. Both modeling and experiments demonstrated that conversion from liquid CO2 to CO2 hydrate increased with water flow rate, ambient pressure, and residence time and decreased with CO2 flow rate. Increased mixing intensity, as expressed by the Reynolds number, enhanced the mass transfer and increased the conversion of liquid CO2 into CO2 hydrate. Using a plume model, we show that hydrate composite particles (for a CO2 loading of 1000 kg/s and 0.25 hydrate conversion) will dissolve and sink through a total depth of 350 m. This suggests significantly better CO2 dispersal and potentially reduced environmental impacts than would be possible by simply discharging positively buoyant liquid CO2 droplets. Further studies are needed to address hydrate conversion efficiency, scale-up criteria, sequestration longevity, and impact on the ocean biota before in-situ production of sinking CO2 hydrate composite can be applied to oceanic CO2 storage and sequestration.     

Extraction,isolation and characterisation of oil bodies from pumpkin seeds for therapeutic use

Pumpkin, a member of the Cucurbitaceae family has been used frequently as functional medicines for therapeutic use. Several phytochemicals such as polysaccharides, phenolic glycosides, 13-hydroxy-9Z, 11E-octadecatrienoic acid from the leaves of pumpkin, proteins from germinated seeds, have been isolated.     

Relationships between subjective and objective assessments of stress at slaughter and meat quality in pigs

A study was carried out to relate subjective and objective measures of stress at slaughter and meat quality in pigs. Thirteen slaughter plants were visited. The systems used for handling the pigs pre-slaughter and the levels of stress experienced by the animals were subjectively assessed. The sound level immediately before stunning was also measured. Generally, systems that were rated as being most stressful also produced higher levels of sound, probably because of the vocalisations of the pigs. As the size of plant increased, there was a tendency for the level of stress, and the recorded sound level, to increase. This appeared to be because larger plants operated faster and were more likely to use restraining conveyors supplied by races to handle the animals before stunning. The restraint associated with these seems stressful to pigs. Five plants were selected for further study. Two had been assessed as having handling systems that produced a low level of stress in the pigs, one as having a system producing a medium level, and two as having poor systems producing high levels of stress. Blood samples were collected at exsanguination, and meat quality was assessed. As the level of subjectively assessed stress experienced by the pigs increased, so did the average blood levels of lactate and creatine phosphokinase (CPK). There was also a progressive increase in the potential incidence of pale, soft, exudative (PSE) and dark, firm, dry (DFD) meat in the plants using more stressful handling systems. Additionally, there were positive relationships between sound level and lactate and CPK, and sound level and indices of poorer meat quality. Cortisol concentrations were not different in pigs killed in the different systems and probably reflect events earlier in the handling process, such as in transport and lairage, rather than the stress experienced immediately before stunning. The overall conclusion was that subjective assessments of the stress suffered by pigs correlate well with objective measures and that higher stress levels are associated with poorer meat quality.     

Space,Politics and Desire: Configuring the Landscape in Post-Revolutionary France

The French Revolution radically reconfigured citizens' views of both real and imagined space. This article sets out to explore this process of reconfiguration and the relationship between politics and space from the period immediately before the French Revolution in 1789 to the collapse of the Empire in 1815 and its aftermath. Although the liberties brought about by the Revolution made access to space one of its defining characteristics, the spaces of the Revolution were characterized by a diversity in which each political constituency made a space of its own choosing. Those spaces took forms as diverse as the pastoral garden, tales of devil abduction, political festivals, space travel, and hallucinatory visions of Jean-Jacques Rousseau's Switzerland. It was only when Napoléon ‘terminated’ the Revolution in 1799 that space was given a rational, homotopic shape, a shape that endured until the imperatives of the Bourbon Restoration required another configuration.     

Study of the effect of γ-dose rate on the oxidation of polypropylene

Polypropylene PP (high and low crystallinity) was λ-oxidized, in the presence of air, using different dose rates (from 2 to 100 rad/s). Oxidation outcomes were identified and quantified by FTIR spectroscopy coupled with derivatization reactions (NO and SF₄). The difficulty to separate secondary and tertiary hydroperoxides from FTIR measurements after NO treatment was addressed. Polymer physical degradation was also monitored during the λ-irradiation process. GPC was used to follow molecular weight changes and tensile tests for elongation at break modifications. Comparison of the extent of oxidation product for-mation over λ-irradiation allowed us to investigate the importance of λ-dose rate on chemical and physical changes of PP. From this, different mechanisms of ketone and ester formation were examined; relationship between the molecular weight changes and the elongation at break modifications was also investigated. © 1996 John Wiley & Sons, Inc.     

Development and evaluation of surface treatments to enhance the fiber-matrix adhesion in PAN-based carbon fiber/liquid crystal polymer composites. Part I: Coupling agent and amine surface treatments

Several surface treatments, using both commercially available coupling agents and reagents containing multiple amines, were applied to commingled continuous as-received AS4 carbon reinforcing fiber/liquid crystal polymer (LCP) matrix fibers. Unidirectional composites (normally 60 vol% carbon fiber) were prepared from as-received and treated commingled fibers and characterized. To estimate the effect the effect of the treatments on fiber-matrix adhesion, short beam shear (SBS) tests were conducted, the failure surfaces were examined, and spectroscopic studies wee performed. The mean SBS strength of the as-received unidirectional AS4 carbon fiber/LCP matrix composite system was 49 MPa. The best coupling agent and amine treatments yielded increases in composite shear strength of ∼ 10 to 20%, relative to the as-received AS4/LCP system. For the amine treatments, ESCA and FTIR analyses suggested of both the carbon and LCP fibers may have caused the increased adhesion. Moreover, SEM analysis of the failure surfaces of SBS specimens from composites prepared with the treated fibers may have caused the increased adhesion. Moreover, SEM analysis of the failure surfaces of SBS specimens from composites prepared with the treated fibers (both with coupling agents and amines) showed that strong fiber-matrix adhesion was present. That is, failure occurred in the LCP matrix material.