44,818 research outputs found
Spacelab 4: Primate experiment support hardware
A squirrel monkey feeder and automatic urine collection system were designed to fly on the Spacelab 4 Shuttle Mission presently scheduled for January 1986. Prototypes of the feeder and urine collection systems were fabricated and extensively tested on squirrel monkeys at the National Aeronautics and Space Administration's (NASA) Ames Research Center (ARC). The feeder design minimizes impact on the monkey's limited space in the cage and features improved reliability and biocompatibility over previous systems. The urine collection system is the first flight qualified, automatic urine collection device for squirrel monkeys. Flight systems are currently being fabricated
The influences of basic physical properties of clayey silt and silty sand on its laboratory electrical resistivity value in loose and dense conditions
Non-destructive test which refers to electrical resistivity method is recently popular in engineering, environmental, archaeological and mining studies. Based on the previous studies, the results on electrical resistivity interpretation were often debated due to lack of clarification and evidences in quantitative perspective. Traditionally, most of the previous result interpretations were depending on qualitative point of view which is risky to produce unreliable outcomes. In order to minimise those problems, this study has performed a laboratory experiment on soil box electrical resistivity test which was supported by an additional basic physical properties of soil test like particle size distribution test (d), moisture content test (w), density test (ρbulk) and Atterberg limit test (LL, PL and PI). The test was performed to establish a series of electrical resistivity value (ERV) with different quantity of water content for clayey silt and silty sand in loose and dense condition. Apparently, the soil resistivity value was different under loose (L) and dense (C) conditions with moisture content and density variations (silty SAND = ERVLoose: 600 - 7300 Ωm & ERVDense: 490 - 7900 Ωm while Clayey SILT = ERVLoose: 13 - 7700 Ωm & ERVDense: 14 - 8400 Ωm) due to several factors. Moreover, correlation of moisture content (w) and density (ρbulk) due to the ERV was established as follows; Silty SAND: w(L) = 638.8ρ-0.418, w(D) = 1397.1ρ-0.574, ρBulk(L) = 2.6188e-6E-05ρ, ρBulk(D) = 4.099ρ-0.07 while Clayey SILT: w(L) = 109.98ρ-0.268, w(D) = 121.88ρ-0.363, ρBulk(L) = -0.111ln(ρ) + 1.7605, ρBulk(D) = 2.5991ρ-0.037 with determination coefficients, R2 that varied from 0.5643 – 0.8927. This study was successfully demonstrated that the consistency of ERV was greatly influenced by the variation of soil basic physical properties (d, w, ρBulk, LL, PL and PI). Finally, the reliability of the ERV result interpretation can be enhanced due to its ability to produce a meaningful outcome based on supported data from basic geotechnical properties
The influences of basic physical properties of clayey silt and silty sand on its laboratory electrical resistivity value in loose and dense conditions
Non-destructive test which refers to electrical resistivity method is recently popular in engineering, environmental, archaeological and mining studies. Based on the previous studies, the results on electrical resistivity interpretation were often debated due to lack of clarification and evidences in quantitative perspective. Traditionally, most of the previous result interpretations were depending on qualitative point of view which is risky to produce unreliable outcomes. In order to minimise those problems, this study has performed a laboratory experiment on soil box electrical resistivity test which was supported by an additional basic physical properties of soil test like particle size distribution test (d), moisture content test (w), density test (ρbulk) and Atterberg limit test (LL, PL and PI). The test was performed to establish a series of electrical resistivity value (ERV) with different quantity of water content for clayey silt and silty sand in loose and dense condition. Apparently, the soil resistivity value was different under loose (L) and dense (C) conditions with moisture content and density variations (silty SAND = ERVLoose: 600 - 7300 Ωm & ERVDense: 490 - 7900 Ωm while Clayey SILT = ERVLoose: 13 - 7700 Ωm & ERVDense: 14 - 8400 Ωm) due to several factors. Moreover, correlation of moisture content (w) and density (ρbulk) due to the ERV was established as follows; Silty SAND: w(L) = 638.8ρ-0.418, w(D) = 1397.1ρ-0.574, ρBulk(L) = 2.6188e-6E-05ρ, ρBulk(D) = 4.099ρ-0.07 while Clayey SILT: w(L) = 109.98ρ-0.268, w(D) = 121.88ρ-0.363, ρBulk(L) = -0.111ln(ρ) + 1.7605, ρBulk(D) = 2.5991ρ-0.037 with determination coefficients, R2 that varied from 0.5643 – 0.8927. This study was successfully demonstrated that the consistency of ERV was greatly influenced by the variation of soil basic physical properties (d, w, ρBulk, LL, PL and PI). Finally, the reliability of the ERV result interpretation can be enhanced due to its ability to produce a meaningful outcome based on supported data from basic geotechnical properties
Automatic and frequency-programmable systems for feeding TMR: state of the art and available technologies
La tecnica di razionamento TMR (Total Mixed Ration) per bovine da latte si \ue8 molto diffusa grazie ai vantaggi offerti. La meccanizzazione si basa su carri miscelatori azionati da operatore. Alcuni limiti sono associabili alla bassa frequenza di distribuzione (1-2 volte/giorno). La recente diffusione di sistemi automatici per la preparazioone e distribuzione di TMR consente di introdurre inedite possibilit\ue0 di gestione dell'alimentazione. Circa 15 costruttori operanti su diversi concetti progettuali sono stati individuati. Tra le principali innovazioni vi \ue8 la possibilit\ue0 di variare la frequenza di distribuzione, modulare la razione, controllare gli orari di distribuzione, stimolare l'attivit\ue0 delle bovine, gestire l'ingestione di sostanza secca. Il lavoro presenta una panoramica sullo stato dell'arte della tecnologia e propone una classificazione dei robot per TMR
Octree-based production of near net shape components
Near net shape (NNS) manufacturing refers to the production of products that require a finishing operation of some kind. NNS manufacturing is important because it enables a significant reduction in: machining work, raw material usage, production time, and energy consumption. This paper presents an integrated system for the production of near net shape components based on the Octree decomposition of 3-D models. The Octree representation is used to automatically decompose and approximate the 3-D models, and to generate the robot instructions required to create assemblies of blocks secured by adhesive. Not only is the system capable of producing shapes of variable precision and complexity (including overhanging or reentrant shapes) from a variety of materials, but it also requires no production tooling (e.g., molds, dies, jigs, or fixtures). This paper details how a number of well-known Octree algorithms for subdivision, neighbor findings, and tree traversal have been modified to support this novel application. This paper ends by reporting the construction of two mechanical components in the prototype cell, and discussing the overall feasibility of the system
Automatic generation of robot and manual assembly plans using octrees
This paper aims to investigate automatic assembly planning for robot and manual assembly. The octree decomposition technique is applied to approximate CAD models with an octree representation which are then used to generate robot and manual assembly plans. An assembly planning system able to generate assembly plans was developed to build these prototype models. Octree decomposition is an effective assembly planning tool. Assembly plans can automatically be generated for robot and manual assembly using octree models. Research limitations/implications - One disadvantage of the octree decomposition technique is that it approximates a part model with cubes instead of using the actual model. This limits its use and applications when complex assemblies must be planned, but in the context of prototyping can allow a rough component to be formed which can later be finished by hand. Assembly plans can be generated using octree decomposition, however, new algorithms must be developed to overcome its limitations
Design project 1968/9: management report
1. INTRODUCTION
The design of an automatic assembly machine with versatility in
application was undertaken as a group project by post-graduate
students attending a course in production technology. This
report summarises the work clone and conclusions reached during
the project. In addition there are available five other reports
which describe the designing of different areas of the machine in
full detail (refs. 1 to 6). There is also the report of a technical
survey which was carried out to investigate industrial requirements
for automatic assembly. In order that this report may serve as a
guide, a summary of the content of each of the other reports is
included
Reducing cross-sucking of group housed calves by an environmental enriched building design
Group housing is a natural and economic way of raising calves. One major disadvan-tage of group housing calves is the occurrence of cross-sucking as an abnormal behaviour. The main objective of our study on organic calf housing was the reduction of cross-sucking related to milk feeding. A new feeding stall with automatic gates was attached to an automatic teat feeder. One gate opened to an enriched area immedi-ately when the calves had finished their milk meal. In this zone calves could use rub-ber teats or a hay net (treatment optimized). The design for the control group used a simple feeding stall without attached enriched zone. 168 female calves (German Holstein) from one origin (herd) were randomly assigned to 14 groups with 12 calves each. Thus, each treatment could be repeated seven times. Two groups were used for preliminary testing of housing and technique. Calves were fed whole milk, according to EU-organic-farming-guidelines. The behaviour of calves was observed directly for 20 minutes following milk intake. In addition, 24 hour video observation completed the behavioural monitoring. The videos were analyzed with the continuous sampling method; statistical analysis was done with the SAS statistical software package and non-parametric procedures. As one result, cross-sucking of calves decreased signifi-cantly in the optimized housing treatment compared to the control treatment: cross-sucking behaviour occurred for 12% of the calves of the optimized treatment vs. 60% cross-sucking calves in the control treatment. Regarding the intensity of cross-sucking, the control group showed 200 cross-sucking bouts per 100 calves and meal, in comparison with a frequency of 16 bouts of the optimized treatment. Our study supports the thesis, that design of housing and environment could be used to reduce cross-sucking of group housed calves. However, future research should be done to evaluate interactions between feeding techniques, environment and physiological processes related to cross-sucking behaviour of calves
Demand feeding system using an infrared light sensor for brown-marbled grouper juveniles, Epinephelus fuscoguttatus
In general, demand feeding devices are equipped with a mechanical trigger switch. Such a switch is not suitable for juvenile fish with a small body size, because the body weight is insufficient to trigger the feeder. An infrared light sensor that does not require the fish to push a feeder switch is more suitable for small fish. The brown-marbled grouper Epinephelus fuscoguttatus is an important fish species in Southeast Asia. The purpose of this study was to compare the growth rates (GRs) of brown-marbled grouper juveniles reared using customised demand feeding devices with an infrared light sensor (the infrared light demand feeder (IRDF) group) and automatic feeding devices (the automatic feeder (AF) group). The results indicated that GRs of standard lengths and body weights showed no significant differences using one-way analysis of variance; however, the standard length of the IRDF group showed a tendency of a higher GR than the AF group. Although the feed conversion ratio (FCR) also showed no significant difference, the FCR of the IRDF group was more efficient, indicating that the IRDF group yielded a more desirable FCR. These results indicate that IRDF can be used in the culture of brown-marbled grouper juveniles. In view of the working schedule of the fish farm staff, IRDF are superior to other feeding devices, because they are less labour-intensive than usual tasks. We conclude that IRDF is a useful feeding system for aquaculture
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