309 research outputs found
Olfactory variation in mouse husbandry and its implications for refinement and standardisation: UK survey of non-animal scents
With their highly sensitive olfactory system, the behaviour and physiology of mice are not only influenced by the scents of conspecifics and other species, but also by many other chemicals in the environment. The constraints of laboratory housing limit a mouse’s capacity to avoid aversive odours that could be present in the environment. Potentially odorous items routinely used for husbandry procedures, such as sanitizing products and gloves, could be perceived by mice as aversive or attractive, and affect their behaviour, physiology and experimental results. A survey was sent to research institutions in the UK to enquire about husbandry practices that could impact on the olfactory environment of the mouse. Responses were obtained from 80 individuals working in 51 institutions. Husbandry practices varied considerably. Seventy percent of respondents reported always wearing gloves for handling mice, with nitrile being the most common glove material (94%) followed by latex (23%) and vinyl (14%). Over six different products were listed for cleaning surfaces, floors, anaesthesia and euthanasia chambers and behavioural apparatus. In all cases Trigene™ (now called Anistel™) was the most common cleaning product used (43, 41, 40 and 49%, respectively). Depending on the attribute considered, between 7 and 19% of respondents thought that cleaning products definitely, or were likely to, have strong effects on standardization, mouse health, physiology or behaviour. Understanding whether and how these odours affect mouse welfare will help to refine mouse husbandry and experimental procedures through practical recommendations, to improve the quality of life of laboratory animals and the experimental data obtained
Apparent stress-strain relationships in experimental equipment where magnetorheological fluids operate under compression mode
Abstract: This paper presents an experimental investigation of two different magnetorheological ( MR) fluids, namely, water-based and hydrocarbon-based MR fluids in compression mode under various applied currents. Finite element method magnetics was used to predict the magnetic field distribution inside the MR fluids generated by a coil. A test rig was constructed where the MR fluid was sandwiched between two flat surfaces. During the compression, the upper surface was moved towards the lower surface in a vertical direction. Stress-strain relationships were obtained for arrangements of equipment where each type of fluid was involved, using compression test equipment. The apparent compressive stress was found to be increased with the increase in magnetic field strength. In addition, the apparent compressive stress of the water-based MR fluid showed a response to the compressive strain of greater magnitude. However, during the compression process, the hydrocarbon-based MR fluid appeared to show a unique behaviour where an abrupt pressure drop was discovered in a region where the apparent compressive stress would be expected to increase steadily. The conclusion is drawn that the apparent compressive stress of MR fluids is influenced strongly by the nature of the carrier fluid and by the magnitude of the applied current
Acetosolv Pulping Modeling of Oil Palm Frond Fibers
Oil palm frond fibers were pulped using acetosolv pulping in laboratory scale batch digester. A central composite desigh was used to investigate the process and to study the effect of its variables on pulp quality and yield. A second order polynomial regression model, using three in dependent process variables, was found to be appropriate for describing acetosolv pulping oil palm fibers. The overall pulping conditions, which maximize yield while subject to a restriction of kappa number 19.93 were estimated at pulping time of 130 mins, a pulping temperature of 153 oC, AcOH of 85 % and HCl of 0.25
Natural fiber for green technology in automotive industry: a brief review
Fiber reinforced polymeric composites have been known and widely used because of their high specific strength and modulus compared to metals. In the last few years, biomaterials listed as a demand technology to be exploring by researchers especially in industrial purpose. This is push by environmental awareness and the over use of petrol resources lead to the development of new materials, called biocomposites, which will maintain a better future. This paper will be discussing about a brief review of natural fibers, use in automotive industry to achieve a green technology target in manufacturing of cars specifically. It's a fact that, related to weight reduction, the automotive industry can take advantages of using these materials, not only because of extinction of oil reserve, but because of high ability and importance of these materials itself in automobiles. Currently, most composites in the market are focused with long-term durability design while using nondegradable polymeric resins such as epoxies and high-strength fiber such as glass. All these materials prove to be a good characteristic of composite but still lack in environmental concern. This polymer and fiber are derived from petroleum, a nonreplenishable commodity. The momentum is to use biocomposites in common plastics to improve performance. Since the main purpose of this paper is to show a bio-composite which is suitable to replace the existing interior of automotive design, the work has focused on obtaining that bio-composite, taking account into the raw-materials cost reduction and the maintenance of the manufacturing process based on current scenario. The automotive industry is in their way to expand green technology in composites because the need is greatest. But producing the composites is energy intensive and polluting, while the durability of conventional composites, often seen as an advantage, is also their biggest challenge. Current fibers use in industry right now is difficult to dispose. They do not degrade naturally and could linger for generations
Antimicrobial activity of fingerroot [Boesenbergia rotunda (L.) Mansf. A.] extract against streptococcus mutans and streptococcus sobrinus
The extract of medicinal plants fingerroot [Boesenbergia rotunda (L.) Mansf. A.] obtained using 100% methanol was tested for antibacterial activity against two major pathogen of dental carries namely Streptococcus mutans KCCM 3309 and Streptococcus sobrinus KCCM 3207. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time-kill curve on S. mutans and S. sobrinus were analyzed using Clinical and Laboratory Standard Institutes (CLSI) methods. Preliminary antimicrobial screening showed the mean zones of inhibition for S. mutans (9.0 mm) and S. sobrinus (8.0 mm). MIC value obtained for S. sobrinus and S. mutans was 313 μg/ml while the MBC values were 313 μg/ml (S.mutans) and 625 μg/ml (S. sobrinus). Time-kill curve were obtained at concentrations of 0xMIC, 1/2xMIC, 1xMIC, 2xMIC, 4xMIC and 8xMIC. S. mutans was found to be more susceptible to the fingerroot extract than S. sobrinus. Time - kill curve showed that the concentration of 8xMIC was able to kill 99.9% of S. mutans after 4 hours treatment. These results may be useful for developing fingerroot B. rotunda as natural anticariogenic agent in toothpaste or any oral care products such as mouthwash in treatment of dental carries, sore throat and flaming gums
POSTURAL DIFFERENCES IN TURNING KICK VS BACK THRUST KICK AMONG TAEKWON-DO PLAYERS: DOMINENT LEG
There are many techniques in Taekwondo involving foots and hands. Through observations, athletes prefer to use techniques, which are easy to score and give more advantages of winning the game. In order to perform the quick movement, the body must rapidly adjust to the differences in posture to maintain a state of balance. Limited
researches have been done on dynamic postural in Taekwondo. The purpose of this study is to determine the differences between the postural response to a turning kick (Dollyo Chagi) and back thrust kick (Dwit Chagi). To achieve the goal stated, 3D biomechanical analysis is done using kinematics approach. The parameters to be obtained are linear displacement of body centre of mass, kicking time duration and velocity of foot
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