E.J. Catchpole and M.S. A.E. in
THE development of synthetic resin adhesives has proceeded very fast since about 1937 when the first urea formaldehyde wood glues were being produced on a pilot scale. The…
Abstract
THE development of synthetic resin adhesives has proceeded very fast since about 1937 when the first urea formaldehyde wood glues were being produced on a pilot scale. The excellent resistance of these materials to weathering conditions has enabled very considerable advances in structural design both in wooden structures and rather more recently in metal aircraft. These synthetic resin adhesives are basically ‘thermosetting’, that is to say, they harden by the addition of catalysts or by the application of heat, the chemical process which takes place being irreversible and not dependent upon the evaporation of solvents. This concept leads not only to good weather resistance, but also to the practicality of sticking together non‐porous materials such as metal. The first use of bonding of mstal in aircraft structures was in the de Havilland Hornet in 1943,1 and since then bonding has proved its advantages over other methods of joining for both primary and secondary structures. Other new methods of fabrication have appeared since that time and the requirements for structures in terms of loading and environment have changed considerably; but both mctal‐to‐metal bonding and its newer partner honeycomb sandwich show signs of much more extensive use in the future. These two most important applications of synthetic resin adhesives in modern aircraft will now be considered.
The design of the Jaguar is remarkable in that optimisation was applied during design. In this paper read before the Royal Aeronautical Society, the authors revealed that the…
Abstract
The design of the Jaguar is remarkable in that optimisation was applied during design. In this paper read before the Royal Aeronautical Society, the authors revealed that the techniques which have for long been dismissed as impractical in aviation have now been proved valid even in the design of military aircraft.
British Aircraft Corporation recently announced the new Board of English Electric Aviation Ltd. and the composition of the Board of Directors of the new company British Aircraft…
Abstract
British Aircraft Corporation recently announced the new Board of English Electric Aviation Ltd. and the composition of the Board of Directors of the new company British Aircraft Corporation (Guided Weapons) Ltd. This follows the announcement that English Electric Aviation is taking over from English Electric Ltd. its aircraft manufacturing facilities at Preston and Salmesbury and that the guided weapons interests of English Electric Aviation and of Bristol Aircraft Ltd. are being integrated under the management of a new company, B.A.C. (Guided Weapons) Ltd.
TURBINE disks are subject to stresses due to two causes; the inertia effects of rotation, and the radial variation of temperature across the disk. Elastic stresses due to each of…
Abstract
TURBINE disks are subject to stresses due to two causes; the inertia effects of rotation, and the radial variation of temperature across the disk. Elastic stresses due to each of these effects may be determined separately and superposed to obtain the resultant stress distribution.
A new approach to the problem of minimum‐weight design of stiffened compression panels is presented. It is predominantly based on the plate instability mode in which the sheet and…
Abstract
A new approach to the problem of minimum‐weight design of stiffened compression panels is presented. It is predominantly based on the plate instability mode in which the sheet and stiffeners, having been stressed to the same degree, simultaneously buckle over a long wavelength with the length of a buckle equal to the pin‐ended length of a panel. Charts to determine the buckling stresses of the modes required for the minimum‐weight design are given. Formulae and charts are presented to compute the effective moment of inertia of a stiffener, a most important quantity, over a wide range of panel proportions, for Z‐section and integrally machined unflanged stiffeners. The principles of minimum‐weight design are discussed and illustrated by the lightest Z‐stiffener panels selected from extensive test data. Comparison of the theoretical stresses of the optimum panels and many other panels of different proportions with those obtained by tests shows good agreement. The principle of dimensional similarity, which is implicit in the buckling mode referred to above, eliminates the effects of size. Results obtained either from theory or tests can therefore be applied to different size panels of like proportions.
Jinyao Zhu, Cong Niu, Jinbao Chen, Chen Wang, Dianfu Liu and Decai Yang
The purpose of this study is to describe the proposed alpha solar rotary mechanism (ASRM) and how it is used to accurately modify the solar array of the China Space Station (CSS…
Abstract
Purpose
The purpose of this study is to describe the proposed alpha solar rotary mechanism (ASRM) and how it is used to accurately modify the solar array of the China Space Station (CSS) in orbit to maintain continuous tracking of the sun to provide power. It also highlights the need to evaluate the performance of the ASRM and predict potential failure modes in various extreme scenarios.
Design/methodology/approach
To evaluate the performance of the ASRM, a dynamic model was created and tested under normal and faulty conditions. In addition, a multidirectional stiffness test was conducted on the prototype to verify the accuracy of the ASRM's dynamic model. The high-precision ASRM model was then used to predict potential failure modes and damaged parts in various extreme scenarios.
Findings
The simulation results were in good agreement with the test results, with a maximum error of less than 8.85%. The high-precision ASRM's model was able to accurately predict potential failure modes and damaged parts in extreme scenarios, demonstrating the effectiveness of the proposed model and simulation evaluation test.
Originality/value
The proposed high-precision ASRM model and simulation evaluation test provide an effective way to evaluate the structural safety and optimize the design of the spacecraft. This information can be used to improve the performance and reliability of the CSS's solar array and ensure continuous power supply to the station.
Details
Keywords
Myrtede Alfred, Ken Catchpole, Emily Huffer, Kevin Taafe and Larry Fredendall
Achieving reliable instrument reprocessing requires finding the right balance among cost, productivity, and safety. However, there have been few attempts to comprehensively…
Abstract
Achieving reliable instrument reprocessing requires finding the right balance among cost, productivity, and safety. However, there have been few attempts to comprehensively examine sterile processing department (SPD) work systems. We considered an SPD as an example of a socio-technical system – where people, tools, technologies, the work environment, and the organization mutually interact – and applied work systems analysis (WSA) to provide a framework for future intervention and improvement.
The study was conducted at two SPD facilities at a 700-bed academic medical center servicing 56 onsite clinics, 31 operating rooms (ORs), and nine ambulatory centers. Process maps, task analyses, abstraction hierarchies, and variance matrices were developed through direct observations of reprocessing work and staff interviews and iteratively refined based on feedback from an expert group composed of eight staff from SPD, infection control, performance improvement, quality and safety, and perioperative services. Performance sampling conducted focused on specific challenges observed, interruptions during case cart preparation, and analysis of tray defect data from administrative databases.
Across five main sterilization tasks (prepare load, perform double-checks, run sterilizers, place trays in cooling, and test the biological indicator), variance analysis identified 16 failures created by 21 performance shaping factors (PSFs), leading to nine different outcome variations. Case cart preparation involved three main tasks: storing trays, picking cases, and prioritizing trays. Variance analysis for case cart preparation identified 11 different failures, 16 different PSFs, and seven different outcomes. Approximately 1% of cases had a tray with a sterilization or case cart preparation defect and 13.5 interruptions per hour were noted during case cart preparation.
While highly dependent upon the individual skills of the sterile processing technicians, making the sterilization process less complex and more visible, managing interruptions during case cart preparation, improving communication with the OR, and improving workspace and technology design could enhance performance in instrument reprocessing.
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Z. F. Bhat, Sunil Kumar and Lokesh Kumar
The purpose of this paper was to explore the possibility of utilization of Ocimum sanctum Linn (Tulsi) leaf extract as a natural preservative in muscle foods. The products…
Abstract
Purpose
The purpose of this paper was to explore the possibility of utilization of Ocimum sanctum Linn (Tulsi) leaf extract as a natural preservative in muscle foods. The products incorporated with Ocimum sanctum leaf extract were assessed for various oxidative stability and storage quality parameters.
Design/methodology/approach
The Ocimum sanctum leaf extract was incorporated at 300 mg/kg level in the formulation. Chicken sausages incorporated with Ocimum sanctum leaf extract along with control samples were aerobically packaged in low-density polyethylene pouches and assessed for lipid oxidation, physicochemical, microbiological and sensory characteristics under refrigerated (4 ± 1°C) conditions.
Findings
Ocimum sanctum leaf extract showed a significant (p < 0.05) effect on the lipid stability, as the treated products exhibited significantly (p < 0.05) lower thiobarbituric acid reactive substances (mg malonaldehyde/kg) and free fatty acid (% oleic acid) values in comparison to control. A significant (p < 0.05) effect was also observed on the microbiological characteristics of the products, as the treated products showed significantly (p < 0.05) lower values for total plate count, psychrophilic count and yeast and mould count. Significantly, (p < 0.05) higher scores were also observed for various sensory parameters of the treated products.
Originality/value
The paper has demonstrated the use of Ocimum sanctum leaf extract as a potential natural preservative, as it successfully improved the oxidative stability and storage quality of the products during refrigerated (4 ± 1°C) storage and may be commercially exploited as a natural preservative in muscle foods.