20505 research outputs found
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The Phishing Game: An Analog Game To Defend UK Organisations From Phishing
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Is TNT Equivalency Still Useful?
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Study of orifice design on oleo-pneumatic shock absorber
Get PDFAircraft oil-strut shock absorbers rely on orifice designs to control fluid flow and optimize damping performance. However, the complex nature of cavitating flows poses significant challenges in predicting the influence of orifice geometry on energy dissipation and system reliability. This study presents a comprehensive computational fluid dynamics (CFD) analysis of the effects of circular, rectangular, semicircular, and cutback orifice profiles on the internal flow characteristics and damping behavior of oleo-pneumatic shock absorbers. High-fidelity simulations reveal that the rectangular orifice generates higher damping pressures and velocity magnitude than those generated by others designs, while the semicircular shape reduces cavitation inception and exhibits a more gradual pressure recovery. Furthermore, the study highlights the importance of considering both geometric and thermodynamic factors in the design and analysis of cavitating flow systems, as liquid properties and vapor pressure significantly impact bubble growth and collapse behavior. Increasing the orifice length had a negligible impact on damping but moderately raised orifice velocities. This research provides valuable insights for optimizing shock absorber performance across a range of operating conditions, ultimately enhancing vehicle safety and passenger comfort.This research was funded by Innovate UK grant number 10002411, under the ATI/IUK Project: LANDOne, with Airbus UK as Industrial Lead.Fluid
A multidisciplinary investigation of a mummified Egyptian head and analysis of its associated resinous material from the Salinas Regional Archaeological Museum in Palermo (Sicily)
Get PDFAmong the 70 items donated by the abbot Antonio Pietro Paternostro to the former National Museum of Palermo (now Salinas Regional Archaeological Museum) in 1870, an ancient Egyptian mummified human head stands out. In 2022 the finding was submitted for a multidisciplinary investigation that relied upon non-invasive or minimally invasive approaches. Investigations revealed that this is a possible female head, which was likely subjected to trans-nasal craniotomy, and dated to the Egyptian Graeco-Roman period. The head was packed with an abundant amount of resin which was analysed using thermogravimetric analysis, infrared spectroscopy, and gas chromatography with mass spectrometry. The analysis suggested that the resin was most likely comprised of a natural resin, pitch, or tar, from the Pinaceae family of conifers, and mixed with other materials including a fat, oil, or wax. The use of multiple sample preparation techniques for the chromatographic analysis provided a high level of confidence in the identification of a wide variety of compounds, including a range of himachalene derivatives, which indicate the inclusion of cedar tar or oil.Journal of Archaeological Science: Report
Design and implementation of an L1 adaptive proportional output feedback controller
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adaptive control based on a proportional adaptation law is presented. The effectiveness of this design is assessed in simulation and validated through real-time testing on an airfoil pitch control wind tunnel experimental rig. Experimental evaluation of the robustness of the controllers, assessed by introducing various disturbances into the control signals, shows that the adaptive control has a better performance compared to PID control, particularly in scenarios with reduced control effectiveness and time-varying disturbances. The experimental results demonstrate the efficacy of the proposed method in practical applications.Actuator
Whole-farm yield map datasets – data validation for exploring spatiotemporal yield and economic stability
Get PDFCONTEXT:
Statistical methods used for delineation of field management zones and yield stability are frequently only applied to relatively small areas, with few studies performing rotational, whole-farm economic spatiotemporal appraisals. To enable accurate economic analysis, yield map datasets must contain minimal errors while cleaning procedures are often used to remove errors, it is rare that cleaned data is validated before its application.
OBJECTIVE:
The objective of this study was to process, validate and combine spatial statistical approaches for a rotational yield map dataset from a whole-farm across 7 crops in a winter wheat based rotation. Developing a framework for using validated yield map datasets to support precision agriculture techniques that are applicable for farm-level decision making.
METHODS:
The rotational completeness of a 10 year combine yield map dataset for a 435 ha farm in Eastern England was assessed. The dataset was cleaned statistically, and its accuracy assessed by comparison with recorded yields from trailer weigh cells. The cleaned, validated, and corrected yield map dataset was used to identify management zones across the whole farm using fuzzy clustering. The temporal stability of management zones and economic performance across the rotation was also assessed.
RESULTS AND DISSCUSION:
Data cleaning methods removed 16% of data points, improving the degree of spatial correlation within the individual yield maps. Independent validation demonstrated varied accuracy of yield maps from combine harvester data and errors in wheat ranged from 0.53 to 1.53 t/ha RMSE. These errors have implications for researchers using combine yield data to develop and validate precision agriculture technologies. This data set required correction before yield data can be applied with confidence for on-farm decision making. Compared to the zones with the highest margin in each field, 34% of zones had an average annual margin loss of >£100 ha. The temporal stability of the resulting management zones also varied. Areas with the lowest economic performance and greatest yield stability across years will potentially see the greatest economic and environmental benefits from precision agriculture techniques.
SIGNIFICANCE:
The accuracy of combine yield map data should not be assumed. The application of these datasets, including for the identification of management zones or in developing precision agriculture techniques should attempt to address this through data cleaning and validation procedures. Only then should it be used for on farm decision making, such as identifying areas with the most economic benefit by applying precision agriculture tools such as variable rate nutrient applications.This work was supported by the UK Natural Environment Research Council through the CENTA Doctoral Training Partnership [NERC Ref: NE/L002493/1], together with the AHDB Strategic Cereal Farm East program PR: 21510033Agricultural System
Investigation of the horizontal collision damage behavior of fruit during transporting based on a new instrumented impactor
Get PDFHorizontal collisions between fruit and rigid walls are a common occurrence in postharvest packaging and transportation. To address this issue, a novel high-precision instrumented impactor was developed, comprising a high-speed imaging system, an ejection device, and a force sensor. Results showed that the impactor was able to effectively simulate the horizontal collision process between various small spherical fruits (such as cherry tomatoes, plums, sweet cherries, and winter jujubes) and packaging materials at three velocities: slow, medium, and high. Output parameters included the impact force and impact time of the fruit acting on each packaging material, as well as the displacement, displacement rate, impact energy, rebound energy, and absorption energy of the fruit. During the horizontal collision simulation, it was observed that the winter jujube exhibited the largest impact force and the shortest impact time among the four types of fruit tested. Conversely, the sweet cherry demonstrated the lowest proportion of damage area when colliding with the EPE board compared to the rigid board and foam board. This study presents a powerful tool for investigating the horizontal collision behaviour between fruit and rigid plates.Postharvest Biology and Technolog
Leadership behaviours for Lean Six Sigma: Jordan as a case study
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This paper aims to identify leadership behaviours in the manufacturing sector in Jordan that enable successful Lean Six Sigma implementation.
Design/methodology/approach
Qualitative data were collected through 27 interviews to identify the leadership behaviours that facilitate Lean Six Sigma and a focus group to categorise the aspects by grouping them into themes. A grounded theory approach was used in the field study. The processes of constant comparisons helped in identifying the relevant aspects of leadership behaviours and integrating specific aspects into themes; these processes were iteratives. Therefore, this research project relies on the grounded theory methodology to collect and analyse the data. The authors also used a focus group to categorise the aspects by grouping them into themes. In that, the aspects were grouped around core categories.
Findings
After analysing the data, 36 aspects have emerged. The data analysis processes helped in discovering the aspects of leadership that support the use of Lean Six Sigma in the manufacturing sector in Jordan. The aspects were developed through an iterative process of analysis until the saturation level was reached. Eight themes that influence the successful use of Lean Six Sigma emerged: Training and development; Continuous improvement and development; Communication; Empowering employees; Motivating employees; Managing qualities and operations; Employees engagement and involvement; and Supporting culture
Research limitations/implications
There are some research limitations to this study, which opens avenues for future research. First, the data was collected through qualitative methods, which limits the generalizability of the results. Future studies are needed to generalize the results to the wider business community. Second, the data was collected only from manufacturing organizations and did not consider other sectors. Future researchers are urged to replicate the study in other sectors. Third, this study considered only Jordanian firms; therefore, the authors call upon further research to investigate other national settings that may have a different business culture.
Practical implications
This study encourages businesses to follow and adopt these behaviours in organisations, which can help in developing desirable behaviours among leaders to reach advanced levels in using Lean Six Sigma. Moreover, practitioners can develop training programmes for developing leaders. Thus, the Lean Six Sigma journey can become smoother by addressing the issues that face practitioners during the different phases of implementing Lean Six Sigma. In that respect, the practical implication of this research is to describe the practices that the leadership of organisations must develop to maintain high levels of Lean Six Sigma deployment.
Originality/value
Scholarly studies in this field are scarce, especially in developing countries, so identifying the leadership behaviours can help researchers create a theory of leadership behaviours for Lean Six Sigma. Furthermore, practitioners of Lean Six Sigma can take into account these behaviours as crucial to the effective use of Lean Six Sigma. They can encourage leaders to follow and adopt these behaviours in organisations which can help in developing desirable behaviours among leaders to reach advanced levels in using Lean Six Sigma. Thus, the Lean Six Sigma journey can become smoother by addressing the issues that practitioners face during the different phases of implementing Lean Six Sigma
Unveiling the potential of a novel alkalophilic Citrobacter freundii IIPDR3 strain in valorizing glycerol to 1,3-propanediol
Get PDFGlycerol-based biotechnological production of 1,3-propanediol (PDO) has taken center stage after its recent commercialization by Metabolic Explorer. The present study unveils the potential of a novel alkalophilic, BSL-1 bacterium Citrobacter freundii IIPDR3 to produce 1,3-PDO from glycerol. The culture conditions were optimized at shake flask level using one-variable-at-a-time (OVAT) approach, and statistically significant parameters were identified. The optimal conditions for batch production of 1,3-PDO were phosphate-buffered glycerol-based medium essentially containing 1.5 gL−1 ammonium sulfate, 3 gL−1 yeast extract, and 0.5 gL−1 magnesium sulphate, temperature 36 °C, pH–stat of 8.0, and inoculum size being ≥ 35 µgbacterial cells/mL on dry cell weight (DCW) basis. Incorporation of 0.2% Tween 80 in the fermentation medium improved glycerol uptake rate and prevented self-flocculation of bacterial cells. Using liquor NH3 as a neutralizing agent, C. freundii IIPDR3 produced a maximum of 18.04 ± 0.76 gL−1 1,3-PDO from pure glycerol, with productivity and yield being 1.72 gL−1 h−1 and 0.53 gg−1, respectively. When the robustness of the strain was tested on crude glycerol (CG), it accumulated 9.65 and 11.11gL−1 1,3-PDO in 7 h and 10.5 h with initial glycerol concentrations of 20 and 40 gL−1, respectively. The study confirms that C. freundii IIPDR3 can be a promising candidate to tackle CG, a prominent waste derived from biodiesel industry, and simultaneously upgrade it to valorized products such as 1,3-PDO.Biomass Conversion and Biorefiner
Design innovation and user experience of sensory interactive experience in museum exhibition space
Get PDFThis research examines the influence of multi-sensory experiences on visitor engagement within museums in the United Kingdom, with particular emphasis on the roles of physical design elements, technological integration, and sensory stimuli. Utilizing a comprehensive literature review, along with observational studies and surveys across 12 specialized museums, this study identifies critical factors that enhance visitor interaction and satisfaction. The findings reveal that the incorporation of interactive and multi-sensory elements, such as augmented reality and tactile exhibits, significantly augments visitor engagement. This study highlights the evolving function of museums as dynamic educational platforms that amalgamate entertainment and learning. It underscores the imperative for future museum designs to adapt to the digital era and cater to the diverse expectations of visitors. The results suggest that a strategic integration of sensory experiences can transform museums into more inclusive and immersive environments, thereby enriching the educational and cultural experiences of their audiences.Frontiers in Artificial Intelligence and Application