Tapping a Deep, 'Pre-Salt' Bounty Regalado, Antonio
Science (American Association for the Advancement of Science),
12/2010, Volume:
330, Issue:
6009
Journal Article
Peer reviewed
Three years ago, a drill bit struck immense oil deposits deep off the coast of Brazil. Brazilian President Luiz Inácio Lula da Silva promised to use the oil revenue for education and public health. ...But Brazil's R&D sector has been first to benefit.
Three years ago, a drill bit struck immense oil deposits deep off the coast of Brazil. Petrobras, the national oil company, tapped undersea fields now estimated to hold about 80 billion barrels of oil and natural gas—about three times the size of the reservoir under Prudhoe Bay, Alaska. It brought the promise of new wealth and expectations that Brazil will climb to the world's top rung of achievement in science and technology. Brazilian President Luiz Inácio Lula da Silva once termed the oil strike "a second independence for Brazil" and promised to use the oil revenue for education and public health. But Brazil's R&D sector has been first to benefit.
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Currently, there is no “timber moment frame structural system,” as the basic glulam beam‐to‐column connections (usually represented by the bolted connections with slotted‐in steel plates) offer ...limited rotational stiffness such that they are usually treated as pin connections. This paper proposes an innovative type of moment‐resisting glulam beam‐to‐column connection reinforced by long steel rods with screwheads (LSRSs) and long self‐tapping screws (STSs). The motivation is to provide a stiff yet resilient beam‐to‐column connection that could possibly be used for the mid‐rise timber moment frame structural system without the need of shear walls or braces. Six specimens with different diameters of LSRSs were designed and experimentally tested to explore their rotational stiffness, moment‐resisting capacities, hysteretic moment‐rotation responses, and the associated failure modes. Results indicated that the proposed connection could provide not only a satisfying moment resistance, but also the energy dissipation and fast repairability that is related with structural seismic resilience. The design procedures and recommendations for the proposed connection were also provided based on the tested results. The presented experimental study serves as a handy reference for future designs and applications of the proposed connection in practical engineering projects.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A mobile application named HLTapper was designed for Android mobile phones to collect and assess real-time alternating finger tapping movement data such as mean tapping speeds, temporal variations of ...tapping intervals, horizontal tapping variances, and vertical tapping variances, from built-in sensors while a subject performs the finger tapping movement task according to directions given through the application interface. The results of a controlled experiment (40 subjects including nine subjects with Parkinson disease, 11 healthy age-matched subjects, and 20 healthy young subjects) and a discriminant analysis revealed sensitivity of 85.71% and specificity of 91.42%, on an average, which suggests that HLTapper would be useful for early diagnosis and personalised treatment plan adjustments of patients with Parkinson disease.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A specialized system for accurate self-tapping medical bone screw testing is developed, fully meeting the requirements of ASTM F543-A4 (YY/T 1505-2016). The onset of self-tap is identified ...automatically according to a change in the slope of the torque curve. Precise load control is applied to determine the self-tapping force accurately. A simple mechanical platform is embedded to ensure the automatic axial alignment of a tested screw with the pilot hole in a test block. In addition, comparative experiments are conducted on different self-tapping screws to verify the system's effectiveness. By the automatic identification and alignment method, both torque curves and axial force curves for each screw exhibit significant consistency. The self-tapping time point derived from the torque curve agrees well with the turning point of the axial displacement curve. The determined self-tapping forces' mean values and standard deviations are both small, which are proved to be effective and accurate in the insertion tests. This work contributes to improving the standard test method for accurate determination of the self-tapping performance of medical bone screws.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Analysis of a new torsional compliance toolholder for tapping operations.•Evaluation of tapping productivity in terms of tool life, power consumption and surface integrity with the proposed ...toolholder.
Internal thread profiles are used widely in manufacturing processes with the aim of assembling/disassembling different components during maintenance activities from the aeronautics sector until common industrial parts. The threading process is one of the last operations carried out to obtain those components, and consequently, it is an operation of high added value. Threading is a complex operation that must carefully synchronize the rotation with the feed movements to avoid tool breakage during the instant of tapping reversion stage. In order to avoid this risk, several toolholders were developed present in the literature but deficiencies in terms of stability and productivity. Therefore, in this work, a new toolholder is proposed in which the common springs used to mitigate the lack of perfect synchronization between rotation and feed movements are replaced by elastic metal pins achieving a torsional compliance toolholder. The results show that the use of the proposed toolholder implies not only a productivity increase but also a surface integrity improvement as well as a stress reduction that the cutting tap is subjected and thus, achieving a substantial improvement in the current tapping processes. In particular, the use of the proposed toolholder implied a 75% reduction of the maximum stress achieved in the reversal instant, improving 20% tool life with an increase of 30% cutting speed. Therefore, the use of the proposed toolholder implies a substantial improvement in the current tapping processes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To optimize the best tapping technique for enhanced gum production with minimal injury to the trees, suitable Moringa oleifera Lam. trees were selected for experimentation, and the trees were treated ...with different tapping techniques for moringa gum production. When gum inducer was applied to trees treated with battery and hand-operated drills with ½ inch drill bit diameter and 1.0 in. drilling diameter, the gum yield was about fifteen times higher than when the inducer was not applied. It was about four times higher for trees treated with hand-operated drills and 1.0 in. drilling diameter. When employing the Gum tapping blazer-75 to develop a blaze, the average gum production was 1.29 times higher than when using a chisel. Bore hole developed with 1.0 in. diameter hand drill with inducer application yielded the highest total gum yield, followed by ½ inch diameter hand drill and ½ inch battery operated drill with inducer application, blaze developed with Gum tapping blazer-75, bore hole developed with 1.0 in. diameter hand drill without inducer application, blaze developed with chisel, bore hole developed with ½ inch hand drill without inducer application, and bore hole developed with battery operated drill having ½ inch drill bit without inducer application, respectively. A regular increasing trend in moringa gum yield was observed almost in all the treatments with an increase in environmental temperature, which indicates that moringa gum can be tapped throughout the year but a higher quantity of gum may be collected during April–September. When employing the Gum tapping blazer-75, blaze is produced on the tree trunk with ease and sharp edges. The use of developed blazer made blazing faster compared with blaze making using chisel. Gum production was higher with gum inducer technology than with any other method when it came to tapping moringa gum from Moringa oleifera trees using a hand drill. Data on quality characteristics determined for engineering can be used as references in development of equipments and machineries for processing and value addition of moringa gum while chemical properties for various applications in food, pharmaceutical and cosmetic industries for development of high value products.
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•Moringa oleifera gum tapping for increasing gum production investigated.•For gum tapping blaze making and inducer methods were investigated.•Gum production was higher during April – September compared with other months.•Gum production was maximum in Gum inducer method.•In inducer method injury to the trees was less compared with blaze method.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Performance of axially-loaded self-tapping screws in hardwood.•Insertion and withdrawal properties of commercial and an innovative screw optimised for hardwood applications.•Analysis of influences ...from wood anatomy group, thread-grain angle and predrilling.•Generic design approach for withdrawal strength of screws inserted in glued laminated timber products.
The stock of deciduous tree species is raising. Some of them feature outstanding high mechanical properties and are thus predestined for load bearing applications in timber engineering. Although the pressure to use these species is growing, the timber industry and engineering sector still stays observant. For some products made of deciduous timber costs are reported, which prevent their competitiveness against products made of coniferous timber and other building products. One way to improve the competitiveness and use of products made of deciduous timber is the development of innovative and specific single fastener and joint solutions with the aim to maintain at its best the high load bearing capacity of these products also at the joints. In this paper the outcomes from a comprehensive testing campaign conducted in frame of the long-term research project hardwood_SCREWS and for two types of self-tapping screws exposed to axial loads are reported. One screw is of commercial type and used as benchmark. The other screw is an innovative alternative and especially developed for applications in deciduous timber. Three groups with specific parameter settings and aims were tested to analyse the following influences on insertion and withdrawal properties: the wood anatomy, the thread-grain angle and the predrilled insertion. The degree in relationships between investigated physical/mechanical properties is quantified by power coefficients. Compared to coniferous timber, these power coefficients outline a disproportional capacity of screws inserted in deciduous timber. Following this, the paper concludes with a generic model approach for calculating the withdrawal strength of axially-loaded self-tapping screws inserted in structural timber or glued laminated timber products made of either coniferous or deciduous timber.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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