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1
Pitt, G. M., L. E. Kuryiowicz, and IP F. Campbell. "EAST SPAR FIELD—FROM DISCOVERY TO SALES." APPEA Journal 36, no. 1 (1996): 30. http://dx.doi.org/10.1071/aj95002.
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The East Spar field is located 40 km west of Barrow Island on the North West Shelf, offshore WA, and contains 23.6 G.m3 (834 Bscf) of proven and probable wet gas in-place in the Early Cretaceous Barrow Group. The trap is structural, but with negligible time closure.At the time of the discovery and early appraisal of East Spar in late 1993, a rapid deregulation of the gas market was taking place. In combination with the concept of a gas pipeline to the central WA Goldfields region, a marketing 'window of opportunity' was created for the East Spar field, if the development could be crystallised in the available period of 9 months. This required appraisal drilling, geotechnical studies, reservoir engineering and facilities engineering to be advanced on parallel fronts, with close co-ordination and communication be tween all disciplines.The concept of an alliance between the East Spar Joint Venture and the engineering/construction contractors was identified as a way of retaining flexibility to alter the development concept during this period, and provide other benefits during the subsequent construction phase. This alliance was ultimately formed to include representatives from WMC (on behalf of the East Spar Joint Venture (ESJV)), Kvaerner-R J Brown and dough Engineering.The East Spar facilities will comprise a subsea completion and gathering system, with all produced fluids being piped to processing facilities on Varanus Island. The treated gas will then be transported to the mainland via the existing sales gas pipeline to the onshore Dampier to Bunbury pipeline, which connects with the Goldfields Gas pipeline. The condensate will be exported from Varanus Island by tanker. First sales are expected in October 1996
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Li, Xiaonan, Sen Peng, and Chunyu Xu. "Research on temperature field distribution calculation of pylon spar on the fire." Journal of Physics: Conference Series 2955, no. 1 (2025): 012055. https://doi.org/10.1088/1742-6596/2955/1/012055.
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Abstract According to the advisory notice requirements, engine mounting sections with materials other than steel and Inconel 718 should be verified that they meet the sufficient safety margin under the fire state. In this paper, the influence of the conditions in the fire zone on the structure of the middle area of the pylon front spar is specified, and the fire scene is selected as the most likely position to destroy the integrity of the force transmission path of the structure. By simulating the boundary conditions in the fire zone, the temperature distribution of the middle area of the pylon front spar is obtained.
3
Craig, A., H. Sit, P. Sheridan, and L. MacLean. "A GEOPHYSICAL APPRAISAL OF THE EAST SPAR GAS/CONDENSATE FIELD." APPEA Journal 37, no. 1 (1997): 12. http://dx.doi.org/10.1071/aj96001.
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III order to appraise and define the East Spar gas/ condensate field the YVA-214-P joint venture has employed various geophysical techniques. The East Spar field is a Top Barrow Group four-way-dip closure in depth, but has no closure in time, requiring accurate velocity interpretation for depth conversion. Evaluation of the field has followed an approach of 2D reprocessing followed by acquisition of a 3D survey. Appraisal techniques have included inversion to acoustic impedance, amplitude versus offset studies and amplitude mapping.Initially defined from regional well control, a velocity model was constructed from multi-vintage velocity data, then later refined from the 3D velocity data. The velocity model was constructed by careful interpretation of normal moveout velocities from seismic processing. The velocity field is affected by anomalous velocities in the shallow section and a slow velocity zone over the field possibly related to gas permeation throughout the sealA probabilistic approach was adopted for depth con version and reserves estimation. Minimum, most likely and maximum case depth maps were derived by perturb ing the velocity model away from well control. Alterna tive depth conversion techniques were employed with varying success to quantify the uncertainty and accuracy of the velocity model.The reservoir sand exhibits a discrete phase change. Such gas sands are notoriously difficult to identify, interpret and map. Slight changes in the reservoir and sealing unit quality affect the phase and amplitude response of the seismic data. Normal incidence seismic models were constructed to analyse the effects of variations in reservoir, seal and sand thickness on the seismic response. These models were used to constrain several attribute based net pay maps. The reserves estimates from these attribute based maps compared favourably with the highest confidence estimates derived from depth mapping.
4
McDiarmid, A. J., P. T. Bingaman, S. T. Bingham, et al. "JOHN BROOKES GAS FIELD DEVELOPMENT." APPEA Journal 45, no. 1 (2005): 13. http://dx.doi.org/10.1071/aj04001.
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The John Brookes gas field was discovered by the drilling of John Brookes–1 in October 1998 and appraisal drilling was completed in 2003. The field is located about 40 km northwest of Barrow Island on the North West Shelf, offshore West Australia. The John Brookes structure is a large (>90 km2) anticline with >100 m closure mapped at the base of the regional seal. Recoverable sales gas in the John Brookes reservoir is about 1 Tcf.Joint venture approval to fast track the development was gained in January 2004 with a target of first gas production in June 2005. The short development time frame required parallel workflows and use of a flexible/low cost development approach proven by Apache in the area.The John Brookes development is sized for off-take rates up to 240 TJ/d of sales gas with the development costing A$229 million. The initial development will consist of three production wells tied into an unmanned, minimal facility wellhead platform. The platform will be connected to the existing East Spar gas processing facilities on Varanus Island by an 18-inch multi-phase trunkline. Increasing the output of the existing East Spar facility and installation of a new gas sweetening facility are required. From Varanus Island, the gas will be exported to the mainland by existing sales gas pipelines. Condensate will be exported from Varanus Island by tanker.
5
Goff, H. B. "FACILITATING ENVIRONMENTAL APPROVALS PROCESS—EAST SPAR." APPEA Journal 36, no. 1 (1996): 665. http://dx.doi.org/10.1071/aj95046.
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A commitment was made in December 1994 to develop the East Spar gas and condensate field, located in Commonwealth waters approximately 40 km NW of Barrow Island. A number of development options were available and the preparation for the environmental approvals process was initiated in mid-1994. Environmental approval for the East Spar project required satisfying State and Federal Government requirements. In the midst of the approvals process, Justice Sackville of the Federal Court handed down his decision in the Gunn's Woodchip case, significantly altering the way in which the Commonwealth Environ-ment Protection (Impact of Proposals) Act (EP(IP)Act) would be interpreted.In the face of considerable uncertainty about how the federal approvals process would then operate, WMC Petroleum as the operator of the development actively promoted dialogue with and solicited input from, community groups and environmental agencies. This approach involved an intensive but relatively informal consultation process at the company's initiative, well in advance of any statutory requirements. When the project was formally assessed by the Commonwealth regulatory agencies, environmental approval was expedited through the informal consultation process. This pro-active approach offers a useful and efficient model for seeking and gaining environmental clearances.
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Tupper, N. P., E. F. Tadiar, D. L. Price, and J. D. S. Goodall. "A REVISED DEPOSITIONAL MODEL FOR EAST SPAR AND ITS IMPACT ON FIELD PERFORMANCE." APPEA Journal 42, no. 1 (2002): 461. http://dx.doi.org/10.1071/aj01025.
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The East Spar gas condensate field is located in production licence WA-13-L in the offshore Carnarvon Basin. Production commenced in 1996 with two subsea wells linked to processing facilities on Varanus Island via a multi-phase pipeline. The pressure performance of the field has been significantly different to predevelopment expectations. This prompted a reexamination of the seismic and well data to investigate the potential for alternative reservoir models.Integrated stratigraphic and seismic interpretation reveals that the Barrow Group reservoir sands were deposited within an incised valley of limited lateral extent. Sea level fall instigated erosion of a valley that on transgression was filled with successive fluvial, estuarine and marine sediments. Good quality sands are expected to be limited to this valley, the upper part of which can be mapped on seismic. Poor sand development in East Spar–2ST is consistent with its location at the edge of the incised valley.Before development, the primary production mechanism was expected to be a strong bottom water drive comparable with other Barrow Group fields in the Carnarvon Basin. The revised depositional model, however, and the observed decline in reservoir pressure, indicate that connection to this regional aquifer is limited. This implies that water influx will probably be later, and ultimate recovery higher, than previously anticipated.
7
Fredriksson, David W., James D. Irish, M. Robinson Swift, and Barbaros Celikkol. "The Heave Response of a Central Spar Fish Cage." Journal of Offshore Mechanics and Arctic Engineering 125, no. 4 (2003): 242–48. http://dx.doi.org/10.1115/1.1600471.
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As the aquaculture industry considers moving into the open ocean, understanding the dynamic response of fish containment structures becomes critical. Identification of possible resonant conditions and motion characteristics is necessary for system structural integrity and maximizing fish survivability. In this study, heave (vertical motion) free release tests of a central spar fish cage were conducted using a combination of physical and finite-element (FE) models and field observations. These tests were performed to investigate the added mass, damping and natural period characteristics of the system in the vertical direction. The test results were analyzed considering both linear and nonlinear damping. The comparison of these tests show that: the damped natural period of this fish cage is longer than 20 seconds; the numerical model underestimates the damping and the cage oscillates longer and at a higher frequency than observed with the field tests; and the physical model is nearly critically damped near equilibrium due to Reynolds number effects at the model scale.
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Meijer, Sjoerd, and Richard Krabbendam. "Transport and installation of 14 mooring piles at 1,300 m water depth with a DP2 heavy lift vessel." APPEA Journal 50, no. 1 (2010): 601. http://dx.doi.org/10.1071/aj09037.
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The Kikeh field is located in water of some 1,300 meters depth, and 65 miles northwest of Labuan, offshore of Sabah (Borneo) in eastern Malaysia. The Kikeh deepwater project (Fig. 1) includes the first spar platform installation outside the Gulf of Mexico. Mooring the 16,400-tonne spar and a tender-assisted drill rig requires the presence of a mooring system comprising 14 mooring piles of different lengths and weights, the largest of which is 55 m long, has a diameter of 2.13 m and weighs 140 tonnes.
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Fischer, F. Joseph, Stergios I. Liapis, and Yannis Kallinderis. "Mitigation of Current-Driven, Vortex-Induced Vibrations of a Spar Platform via “SMART” Thrusters." Journal of Offshore Mechanics and Arctic Engineering 126, no. 1 (2004): 96–104. http://dx.doi.org/10.1115/1.1643086.
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The possibility of using active-control technology to mitigate long-period (100–300 s) motions of spar platforms was investigated. In particular, the technical feasibility and cost-effectiveness of using a thruster-based active-control system was examined. Only vortex-induced vibrations (VIV) of a moored spar were considered for this study, although it is believed that similar active-control systems can contend equally well with low-frequency wave-drift and wind-induced motions. VIV has been selected for this demonstration due to the considerable attention it has received for spars, because of the high cost for passive VIV-mitigation means. The investigation employed numerical simulations of the hydrodynamics around the spar in two and three dimensions. In particular, for this study, Navier-Stokes methods were used to compute the strongly nonlinear interactions between the current-flow field and the spar hull. The fluid forces (hull-integrated pressures) were then used to compute the unsteady motions of the moored spar. The effect of the motion-controlling thrusters was included as an additional external force—that also varies with time. Of the several different control strategies that were examined, it was found that the most effective one is “D-Control” wherein thruster forces are proportional to spar velocities. Using such control, spar motions can be kept below 35% of the spar diameter, whereas uncontrolled responses were computed to be as high as 80% of the spar diameter. Similar uncontrolled motions have actually been observed in current-tank model tests of spars. As part of this study, discussions were held with engineers from three different thruster companies to ascertain the number and type of thrusters that would be required to achieve desirable VIV mitigation—given the computed thruster-forces, and to provide prudent reliability. Associated costs were also very much of interest. For the spar system examined here, which is representative of those introduced into or being considered for the Gulf of Mexico, it was found that the cost of the thrusters and their electric motors is around $8 million—a cost that is significantly less than that estimated for passive VIV-control devices such as helical strakes, or discontinuous hull geometries. Furthermore, the proposed thruster system could also be employed to contend with (to mitigate) other undesirable, large-amplitude, near-resonant spar motions, e.g., low-frequency drift, for which there are no alternative remedies at present.
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Acosta, Dimitri, Peter T. Doran, and Madeline Myers. "GIS tool to predict photosynthetically active radiation in a Dry Valley." Antarctic Science 32, no. 5 (2020): 315–28. http://dx.doi.org/10.1017/s0954102020000218.
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AbstractUnderstanding primary productivity is a core research area of the National Science Foundation's Long-Term Ecological Research Network. This study presents the development of the GIS-based Topographic Solar Photosynthetically Active Radiation (T-sPAR) toolbox for Taylor Valley. It maps surface photosynthetically active radiation using four meteorological stations with ~20 years of data. T-sPAR estimates were validated with ground-truth data collected at Taylor Valley's major lakes during the 2014–15 and 2015–16 field seasons. The average daily error ranges from 0.13 mol photons m-2 day-1 (0.6%) at Lake Fryxell to 3.8 mol photons m-2 day-1 (5.8%) at Lake Hoare. We attribute error to variability in terrain and sun position. Finally, a user interface was developed in order to estimate total daily surface photosynthetically active radiation for any location and date within the basin. T-sPAR improves upon existing toolboxes and models by allowing for the inclusion of a statistical treatment of light attenuation due to cloud cover. The T-sPAR toolbox could be used to inform biological sampling sites based on radiation distribution, which could collectively improve estimates of net primary productivity, in some cases by up to 25%.
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Bevilaqua, Carlo, Paul T. Bingaman, Matthew S. Dielesen, Kerry A. Graham, and David C. Jennette. "The Halyard gas discovery: a case study." APPEA Journal 49, no. 2 (2009): 592. http://dx.doi.org/10.1071/aj08065.
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The Halyard—1 exploration well discovered gas in a new and separate reservoir unit at the top of the Barrow Group along the outer margin of the Barrow Delta. The well is located in WA—13—L, approximately 15 km northwest of the East Spar Field and 4 km east-northeast of the Spar—1 well. It was drilled in February 2008 and intersected 27.8 m of net gas pay in a Valanginian age Barrow Group reservoir interpreted to be a wave-dominated shoreface sandstone. The nearby Spar—1 well was drilled in 1976 and intersected 18.4 m of net gas pay in an older Barrow Group Sandstone within a distinctly separate, delta-front turbidite setting. The Halyard and Spar fields are located within the overall confines of a structural closure at the Top Barrow Formation level. Earlier reservoir models dating back to the 1970s assumed connectivity between all permeable sandstones within the Top Barrow closure. Critical analysis and integration of all subsurface and engineering data sets inclusive of modular formation dynamics tester (MDT) pressures, condensate gas-ratios, production test data, post-drill amplitude variation with offset (AVO) modelling and seismic facies mapping, however, indicate these reservoirs are distinct and separate stratigraphic traps formed by successive, sequentially sealed depositional units within a larger delta slope edge sequence. Collection of this data has yielded considerable insight into what historically have been viewed as simple traps. In our view and experience, the Barrow Group geology is much more complex with many traps typified by critical stratigraphic components in their trapping mechanism. The Halyard discovery is an example of the type of trap we expect to host much of the remaining reserve potential in the proximal Barrow Delta.
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Wright, Blake. "BP’s Argos FPU Offers Fresh Lessons for the Future of Deepwater GOM Projects." Journal of Petroleum Technology 75, no. 07 (2023): 38–45. http://dx.doi.org/10.2118/0723-0038-jpt.
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Tipping the scales at well over 60,000 tons, BP’s Argos platform is a giant among giants in the deepwater US Gulf of Mexico (GOM). Standing 27 stories tall, the platform has a deck the length and width of an American football field and is one of BP’s largest in the region. One-time KBR subsidiary GVA designed the semisubmersible, the centerpiece of the supermajor’s $9 billion Mad Dog II project built to unlock additional production potential of the Miocene-aged reservoirs estimated to hold more than 5 billion bbl of oil in place. But that wasn’t always the plan. Over a decade ago, BP’s Mad Dog II looked quite different. On paper, the producer was looking at an all-subsea development tied back to another large spar platform—dubbed Big Dog—to host the additional reserves. The development plan envisioned a massive truss spar. Its topsides would need to be installed via three separate offshore lifts then fully integrated at the field site. Any offshore heavy lift is an execution risk. In 1998, an accident while lifting the south module onto Texaco’s Petronius compliant tower in the GOM resulted in the loss of that section of the topsides and delayed the project for a year and a half. That module weighed 3,600 tons. Another hesitation for BP? The price tag. All-in, the spar-based Mad Dog II solution was estimated to cost around $19 billion. That included 30-plus wells. Ultimately, the spar concept was scrapped, and BP moved back to square one and a blank sheet of paper. “The reserves were there,” said Chris Ruthven, project general manager, Mad Dog II. “We knew the reserves were there. In fact, ironically, the team developed the field with the smallest of the four big platforms that BP did back at that point in time: Thunder Horse, Holstein, Atlantis, and Mad Dog. It was the smallest, but ultimately, it was the second-biggest field. It turned out to be huge. All that appraisal showed we’ve got a lot of reserves. So, we went back and went with an analog to Atlantis. Atlantis was seen as a good fit requiring much less offshore integration work. Operations loved the asset, and it was a very safe design. We landed on that concept, and we tried to keep it almost pretty much the same in terms of the overall layout of the facility, but it’s a little bit bigger footprint.” Mad Dog proper was discovered in 1998 via an exploration well in over 6,100 ft of water located in Green Canyon Block 826. The well was drilled to a measured depth of 22,410 ft and encountered around 215 ft of hydrocarbon-bearing Miocene reservoirs. The discovery was followed by a 1999 well drilled to a total depth of 22,410 ft and a further successful appraisal well in February 2000. Mad Dog, covering Green Canyon blocks 825, 826, and 782, was sanctioned as a spar-based development in 2002. The project came online in early 2005.
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Viselga, Gintas. "Research of Accuracy Parameters of the Gantry Course." Solid State Phenomena 113 (June 2006): 50–54. http://dx.doi.org/10.4028/www.scientific.net/ssp.113.50.
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A laser instrument maintains the course of the positioned gantry module. A laser beam generator emitting a vertical beam is placed at the end of the experimental field. A laser beam catcher with photo diodes is mounted onto a positioned gantry module replaceable support. Course deviations were assessed in two cases: when laser, straight-course maintaining mechanism was mounted at the same end of the spar as positioning trundle; and when it was mounted at the middle of the spar. Furthermore, we estimated how course deviations vary when changing the interaxial distance of laser catcher photodiodes. An electromechanical transmitter was used in the tests. The gantry module is positioned by a special positioning trundle and is run by a 12 V electric motor through a worm self - braking reduction gear.
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Ozbek, Emre, Selcuk Ekici, and T. Hikmet Karakoc. "Unleashing the Potential of Morphing Wings: A Novel Cost Effective Morphing Method for UAV Surfaces, Rear Spar Articulated Wing Camber." Drones 7, no. 6 (2023): 379. http://dx.doi.org/10.3390/drones7060379.
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The implementation of morphing wing applications in aircraft design has sparked significant interest as it enables the dimensional properties of the aircraft to be modified during flight. By allowing manipulation of the 2D and 3D parameters on the aircraft’s wings, tail surfaces, or fuselage, a variety of possibilities have arisen. Two primary schools of thought have emerged in the field of morphing wing applications: the mechanisms school and the smart surfaces approach that uses shape-memory materials and smart actuators. Among the research in this field, the Fishbone Active Camber (FishBAC) approach has emerged as a promising avenue for controlling the deflection of the wing’s trailing edge. This study revisits previous research on morphing wings and the FishBAC concept, evaluates the current state of the field, and presents an original design process flow that includes the design of a unique and innovative UAV called the Stingray within the scope of the study. A novel morphing concept developed for the Stingray UAV, Rear Spar Articulated Wing Camber (RSAWC), employs a fishbone-like morphing wing rib design with rear spar articulation in a cost-effective manner. The design process and flight tests of the RSAWC are presented and directly compared with a conventional wing. Results are evaluated based on performance, weight, cost, and complexity. Semi-empirical data from the flight testing of the concept resulted in approximately a 19% flight endurance increment. The study also presents future directions of research on the RSAWC concept to guide the researchers.
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Civera, Marco, Luca Zanotti Fragonara, and Cecilia Surace. "Using Video Processing for the Full-Field Identification of Backbone Curves in Case of Large Vibrations." Sensors 19, no. 10 (2019): 2345. http://dx.doi.org/10.3390/s19102345.
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Nonlinear modal analysis is a demanding yet imperative task to rigorously address real-life situations where the dynamics involved clearly exceed the limits of linear approximation. The specific case of geometric nonlinearities, where the effects induced by the second and higher-order terms in the strain–displacement relationship cannot be neglected, is of great significance for structural engineering in most of its fields of application—aerospace, civil construction, mechanical systems, and so on. However, this nonlinear behaviour is strongly affected by even small changes in stiffness or mass, e.g., by applying physically-attached sensors to the structure of interest. Indeed, the sensors placement introduces a certain amount of geometric hardening and mass variation, which becomes relevant for very flexible structures. The effects of mass loading, while highly recognised to be much larger in the nonlinear domain than in its linear counterpart, have seldom been explored experimentally. In this context, the aim of this paper is to perform a noncontact, full-field nonlinear investigation of the very light and very flexible XB-1 air wing prototype aluminum spar, applying the well-known resonance decay method. Video processing in general, and a high-speed, optical target tracking technique in particular, are proposed for this purpose; the methodology can be easily extended to any slender beam-like or plate-like element. Obtained results have been used to describe the first nonlinear normal mode of the spar in both unloaded and sensors-loaded conditions by means of their respective backbone curves. Noticeable changes were encountered between the two conditions when the structure undergoes large-amplitude flexural vibrations.
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Li, Sanai, David H. Fleisher, Dennis Timlin, et al. "Improving Simulations of Rice in Response to Temperature and CO2." Agronomy 12, no. 12 (2022): 2927. http://dx.doi.org/10.3390/agronomy12122927.
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Crop models are frequently used to assess the impact of climate change responses. Evaluation of model performance against empirical data is crucial to establish confidence, particularly for rice (Oryza sativa L.), one of the world’s important cereal crops. Data from soil-plant-atmosphere-research (SPAR) chambers and field plots were used to assess three versions of the ORYZA model to a range of climate conditions. The three versions were: V1–the original, V2–V1 plus a revised heat stress component, and V3–V2 plus a coupled leaf-level gas exchange algorithm. Comparison against SPAR datasets, which covered a range of temperatures at two CO2 levels, indicated successive improvement in yield predictions with the model version. Root Mean Square Error (RMSE) decreased by 520 and 647 kg ha−1 for V2 and V3, respectively, and Wilmott’s index of agreement improved by 10 and 12% compared with V1 when averaged across 20 treatments and three cultivars. Similar improvements were observed from 17 field dataset simulations with two additional varieties. These results indicated the importance of improving heat sterility functions and carbon assimilation methodologies that incorporate direct responses to air temperature and CO2 concentration in rice models. Accounting for cultivar differences in thermal sensitivity is also an important consideration for climate assessments.
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Slyamov, Azat, Adriaan van Roosmalen, Mads A. Pedersen, et al. "Defect detection in carbon fiber-reinforced composites using directional dark-field imaging and tomography." IOP Conference Series: Materials Science and Engineering 1293, no. 1 (2023): 012016. http://dx.doi.org/10.1088/1757-899x/1293/1/012016.
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Abstract This paper proposes the use of circular X-ray grating interferometry as an effective technique for defect detection with potential applications for in-line inspection of carbon fiber-reinforced pultruded profiles used inside the load-carrying spar caps of wind turbine blades. A fuzzball defect in the pultruded profile is characterized as a demonstration. The method allows for large field-of-view quantification of local fiber alignment and relative fiber volume fraction. A two-dimensional through the thickness averaged distribution of the fiber orientation, the mean scattering, and fractional anisotropy are determined. Based on this, it is possible to determine the size of the defect as well as quantify the severity of the defect.
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Kuttukkan, Shibli, Uzhunnan Faisal, and Joshin Joseph. "Mapping knowledge landscapes in influencer marketing and social media: A scientometric perspective." Multidisciplinary Reviews 8, no. 3 (2024): 2025071. http://dx.doi.org/10.31893/multirev.2025071.
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This study examines influencer marketing on social media from a bibliometric perspective, using the SPAR-4-SLR framework. It provides a quantitative evaluation of productivity, authorship, citation sources, and research domains by analyzing 1,067 peer-reviewed articles from the Scopus database. Additionally, the study offers a scientometric analysis of key indicators related to influencer marketing on social media, such as the domain's evolution, leading authors and sources, the impact of scholarly work, and insights into the scientific production process. Performance analysis techniques, including Total Publications, Productivity per Active Year, Total Citations, Average Citations (AC), Collaboration Index (CI), h-index, g-index, and h-10 index, were used to identify research trends. To decompose the intellectual structure of the topic, science mapping techniques such as co-word analysis, co-citation analysis, and thematic mapping were employed, following the SPAR-4-SLR framework. The study’s findings offer transparent and systematic insights into the intellectual dynamics and conceptual foundations of influencer marketing on social media, highlighting the cumulative advancements in this field. Emerging topics like virtual influencers and influencer credibility were identified as trends for future research. This comprehensive understanding of influencer marketing, its conceptual dynamics, and structural perspective will assist marketers (brands), policymakers (governments), academics, and social media service providers in shaping policies and guiding future research through the quantitative analysis of existing literature in this field.
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Sibley, D., F. Herkenhoff, D. Criddle, and M. McLerie. "REDUCING RESOURCE UNCERTAINTY USING SEISMIC AMPLITUDE ANALYSIS ON THE SOUTHERN RANKIN TREND, NORTHWEST AUSTRALIA." APPEA Journal 39, no. 1 (1999): 128. http://dx.doi.org/10.1071/aj98009.
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Between 1973 and 1996 West Australian Petroleum Pty Limited (WAPET) discovered five major gas fields on the southern Rankin Trend including Spar, West Tryal Rocks, Gorgon, Chrysaor, and Dionysus (collectively termed the Greater Gorgon Resource). Recent discoveries at Chrysaor and Dionysus emphasise the role of subtle 3D seismic attributes in finding hydrocarbons and defining reserves with a minimum number of wells.The Gorgon, Chrysaor, and Dionysus fields were covered by 3D seismic data shot in 1991 and 1995, which led WAPET to discover Chrysaor and later Dionysus. Subsequent to the 3D acquisitions, field reservoirs have been correlated with anomalous seismic events (seismic amplitude and amplitude versus offset) that conform to depth structure. Follow-up work has shown that combining these 3D seismic attributes improves the prediction of wet sands, gas sands, and other lithologies.The resulting understanding and confidence provided by this 3D seismic has driven an aggressive exploration program and defined field reserves at a high confidence level. Results include the recent award of permit area WA-267-P to WAPET and the ongoing studies to begin development of the Greater Gorgon Resource.
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Rana, Vivek Singh, and Tanuj Nandan. "Retrospect and prospect review: Financial literacy and its influence on the process of making financial decisions using SPAR-4-SLR protocol." Multidisciplinary Reviews 8, no. 5 (2024): 2025139. https://doi.org/10.31893/multirev.2025139.
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This study aims to provide a comprehensive understanding of qualitative and quantitative information about the ever-evolving field of financial literacy and its influence on the process of making financial decisions. The research encompasses an examination of 530 publications published in Scopus-indexed journals between 2009 and 2023. This study was conducted using the SPAR-4-SLR protocol. The analysis was done with the help of Biblioshiny, an R-developed online application from the Bibliometrix package, together with VOSviewer software for analytical and visualization purposes. The study employs a systematic review and bibliometric analysis to extract valuable insights from the extensive body of literature. A comprehensive scientific cartography of this area has not yet been presented; therefore, this study aims to synthesize the current knowledge frameworks within the field and determine the dominant research patterns in the specific area of investigation. According to the results, financial literacy issues have evolved over time as an interdisciplinary field. Initially, researchers focused their attention on socioeconomic and demographic variables. However, as time progressed, the scope of the study broadened to include other dimensions, such as psychological and behavioral elements that influence individuals' financial decision-making processes. The scientific mapping conducted in this study is limited to the Scopus database because of its comprehensive inclusion of articles of high quality. The authors suggest several areas for future research that could help resolve the inconsistencies found in the systematic review and bibliometric analysis. The research has the potential to provide valuable insights that can inform the development of policies in the fields of financial education and literacy.
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Lalrengpuii, Manish Kumar Srivastava, and Vinnarasi Belavandran. "Trends in virtual influencers (VIs): A bibliometric analysis and SPAR-4-SLR protocol." Multidisciplinary Reviews 7, no. 12 (2024): 2024285. http://dx.doi.org/10.31893/multirev.2024285.
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This study aims to comprehensively understand qualitative and quantitative information about the current trends in VIs. It examines 106 articles published in Scopus-indexed journals between 2020 and 2024. The analysis was done with the help of Biblioshiny, an R-developed online application from the Bibliometrix package, and VOSviewer software for analytical and visualization purposes. This study was conducted using the SPAR-4-SLR protocol. The findings showed that recent years have been more productive, and many authors have demonstrated their interest in studying the VIs. Recent trends are social media, virtual reality, marketing, social networking, etc. The study employs a systematic review and bibliometric analysis to extract valuable insights from the extensive body of literature. These insights suggested several areas for future research, providing a roadmap for future researchers to proceed with their research in this area. The comprehensive scientific cartography of the area has yet to be presented; therefore, this study aims to synthesize the current knowledge frameworks within the field and determine the dominant research patterns in the specific area of investigation.
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Zaharia, Sebastian Marian, Mihai Alin Pop, and Răzvan Udroiu. "Reliability and Lifetime Assessment of Glider Wing’s Composite Spar through Accelerated Fatigue Life Testing." Materials 13, no. 10 (2020): 2310. http://dx.doi.org/10.3390/ma13102310.
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The evaluation of the reliability and the lifetime of aerospace components has become an important segment of the design stage. The aeronautical components are subjected to complex, rigorous tests and have a long test life. The main goal in the field of aviation is to have components with high reliability and quality and to meet the mandatory requirements and regulations. The spars are stiffening components positioned along the wing and which take up most of the load and are tested for fatigue over a long period of time. The spar which was analysed in this study has a sandwich structure with GFRP (glass fiber reinforced plastic) skin and foam core. In this paper, the performances in the static and dynamic conditions of the GFRP-foam sandwich structures cut out of the composite spar of a glider were analysed. Additionally, using accelerated techniques based on the three-point fatigue bending test, the main reliability indicators of the GFRP-foam sandwich structures were determined. Using the statistical processing of the experimental data and the Inverse Power Law–Weibull acceleration model, the mean number of cycles to failure, in normal testing conditions of the GFRP-foam specimens was determined, with a value of 102,814. Using the accelerated testing techniques of the GFRP-foam sandwich structures an important decrease of the test time (8.43 times) was obtained.
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Luminosu, I., D. Popov, and I. Zaharie. "Spectral absorption of unpolarized light through nano-materials in the absence of a magnetic field." Science of Sintering 40, no. 3 (2008): 223–34. http://dx.doi.org/10.2298/sos0803223l.
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A study of optical properties, such as light absorption, of a colloidal nano-material, provides information on the biphasic, solid - liquid system microstructure. The nano-material under study is a magnetic liquid (ferrofluid). The disperser agent is petroleum mineral oil and the dispersed material is a brown spar powder (nano-particles). The stabilizer is oleic acid. Light absorption through ferrofluid samples reveals the tendency of solid particles in a colloidal solution to form aggregates. The paper emphasizes the linear dependence between the spectral absorption coefficient, concentration and wavelength. The aggregates cause deviations of the extinction coefficient from values according to the Bouger-Lambert-Beer law. Fe3O4 aggregates sized 58.76 nm are formed in the system. The average number of nano-particles forming aggregates is 6. The magnetic liquid to be studied is secure stable and, thus, trustful in technological and biological applications.
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Torsvik, Jone, Amir R. Nejad, and Eilif Pedersen. "Experimental field study of floater motion effects on a main bearing in a full-scale spar floating wind turbine." Marine Structures 79 (September 2021): 103059. http://dx.doi.org/10.1016/j.marstruc.2021.103059.
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Ding, Minting, and Zhenlei Chen. "Study on a Circular Cylindrical Floating Device and Its Motion Response Characteristics." Journal of Physics: Conference Series 2419, no. 1 (2023): 012010. http://dx.doi.org/10.1088/1742-6596/2419/1/012010.
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Abstract In this paper, a circular cylindrical floating device design is proposed by combining the structural features of the cylindrical Floating Production Storage and Offloading (FPSO) and the deep-sea Spar platform. It is suitable for deep-water oil and gas field development environment in the South China Sea. This floating device adds six floats with a Spar platform hard tank role based on the cylindrical FPSO to improve the buoyant center. This paper analyzes the motion response characteristics of the circular cylindrical floating device in waves by the Eulerian multi-phase flow model of STAR-CCM+. The results show that the pitch motion characteristics of the circular cylindrical floating device are better than those of the cylindrical FPSO and ship-type FPSO in the reference [8]. In addition, the paper also investigates the motion response of the circular cylindrical floating device with different directions of the incoming flow. The analysis shows that this floating device has the lowest motion response at 30° direction incoming flow. And the Response Amplitude Operator (RAO) of pitch motion shows a negative correlation with the incoming flow direction. The research results of this paper can provide a reference for the future development of marine resources, and have a certain practical significance.
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Tao, Jiangchuan, Ye Kuang, Nan Ma, et al. "Secondary aerosol formation alters CCN activity in the North China Plain." Atmospheric Chemistry and Physics 21, no. 9 (2021): 7409–27. http://dx.doi.org/10.5194/acp-21-7409-2021.
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Abstract. Secondary aerosols (SAs, including secondary organic and inorganic aerosols, SOAs and SIAs) are predominant components of aerosol particles in the North China Plain (NCP), and their formation has significant impacts on the evolution of particle size distribution (PNSD) and hygroscopicity. Previous studies have shown that distinct SA formation mechanisms can dominate under different relative humidity (RH). This would lead to different influences of SA formation on the aerosol hygroscopicity and PNSD under different RH conditions. Based on the measurements of size-resolved particle activation ratio (SPAR), hygroscopicity distribution (GF-PDF), PM2.5 chemical composition, PNSD, meteorology and gaseous pollutants in a recent field campaign, McFAN (Multiphase chemistry experiment in Fogs and Aerosols in the North China Plain), conducted during the autumn–winter transition period in 2018 at a polluted rural site in the NCP, the influences of SA formation on cloud condensation nuclei (CCN) activity and CCN number concentration (NCCN) calculation under different RH conditions were studied. Results suggest that during daytime, SA formation could lead to a significant increase in NCCN and a strong diurnal variation in SPAR at supersaturations lower than 0.07 %. During periods with daytime minimum RH exceeding 50 % (high RH conditions), SA formation significantly contributed to the particle mass and size changes in a broad size range of 150 to 1000 nm, leading to NCCN (0.05 %) increases within the size range of 200 to 500 nm and mass concentration growth mainly for particles larger than 300 nm. During periods with daytime minimum RH below 30 % (low RH conditions), SA formation mainly contributed to the particle mass and size and NCCN changes for particles smaller than 300 nm. As a result, under the same amount of mass increase induced by SA formation, the increase of NCCN (0.05 %) was stronger under low RH conditions and weaker under high RH conditions. Moreover, the diurnal variations of the SPAR parameter (inferred from CCN measurements) due to SA formation varied with RH conditions, which was one of the largest uncertainties within NCCN predictions. After considering the SPAR parameter (estimated through the number fraction of hygroscopic particles or mass fraction of SA), the relative deviation of NCCN (0.05 %) predictions was reduced to within 30 %. This study highlights the impact of SA formation on CCN activity and NCCN calculation and provides guidance for future improvements of CCN predictions in chemical-transport models and climate models.
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Doherty, Cain, and Wing Kong Chiu. "Wave Scattering Phenomena for Health Monitoring of Hard-to-Inspect Defects ." Solid State Phenomena 185 (February 2012): 5–8. http://dx.doi.org/10.4028/www.scientific.net/ssp.185.5.
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Doherty and Chiu reported on the potential use of propagating stress waves for monitoring fatigue crack development in a series of hard-to-inspect weep holes in the wing spar of an aging aircraft. New experimental evidence showed an interesting scattering phenomenon at the defect and demonstrated the ability to use this phenomenon to monitor the development of an upward developing fatigue crack. It was found that a scattered field can be used to highlight the presence of a source of a secondary wave mode arising from the interaction of the incident wave field with the defect. A detailed investigation into these observations will contribute to the creation of new basic scientific understanding of this phenomenon with the potential development of a novel and optimised approach for quantitative inspection of hard-to-inspect regions in a structure.
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Tanaka, Koji, Iku Sato, Tomoaki Utsunomiya, and Hiromu Kakuya. "Validation of dynamic response of a 2-MW hybrid-spar floating wind turbine during typhoon using full-scale field data." Ocean Engineering 218 (December 2020): 108262. http://dx.doi.org/10.1016/j.oceaneng.2020.108262.
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Jagadeeswari, S., and Madhumita Das. "Mapping the landscape: Bibliometric trends in gender diversity research (2013-2023)." Multidisciplinary Reviews 7, no. 10 (2024): 2024236. http://dx.doi.org/10.31893/multirev.2024236.
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This study delves into the realm of gender diversity research, by scrutinizing published scientific studies from 2013 to 2023. Using the Scopus repository, an analysis is conducted on bibliometric characteristics employing tools such as Vosviewer, R-studio, and SPAR-4. The results indicate a notable 211% surge in gender diversity publications over the span of a decade, predominantly in scholarly periodicals (72.64%). Notably, the United States and the United Kingdom dominate this field, accounting for nearly half of all related research. Eminent scholars such as Galbreath (USA) and Kulik (UK) are recognized for their scholarly contributions, while the journal "Academic Medicine" has emerged as a frontrunner in terms of paper dissemination. In contrast to the abundance of bibliometric analyses in the natural and life sciences, the social sciences, particularly gender diversity studies, have not received commensurate attention. This investigation addresses this gap by providing valuable insights into trends in academic publishing, prominent authors and publications, and the geographical distribution of contributions within this critical domain of social science. Through its comprehensive examination, this study enables future research endeavours by shedding light on significant contributions and areas warranting further exploration.
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Bokadia, Srishti, Ruchi Jain, and Rushina Singhi. "Recommender systems: A systematic literature review, synthesis and framework for future capabilities." Multidisciplinary Reviews 7, no. 7 (2024): 2024157. http://dx.doi.org/10.31893/multirev.2024157.
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This study offers a comprehensive exploration of recommender systems (RSs) with a focus on their influence on consumers’ purchase intentions in the realm of e-commerce. Employing the Scientific Procedures and Rationales for Systematic Literature Reviews (SPAR-4-SLR) method, the authors identified and evaluated 908 high-quality papers to systematically categorize RS. This paper outlines these categories and reviews major developments within them, identifying significant constructs influencing consumer purchasing decisions. The outcome is a conceptual framework illustrating the interrelationships among these constructs, providing a novel contribution to the literature. This framework lays the groundwork for future studies in the field and provides valuable insights for marketing professionals seeking to develop RS-based strategies.
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Teodoreanu, Ioana, and Cristian Ionut Ivanov. "The Importance of Understanding the Stakeholders in Industry Actions - A Corporate Social Responsibility Perspective." Advanced Materials Research 837 (November 2013): 669–72. http://dx.doi.org/10.4028/www.scientific.net/amr.837.669.
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A great pressure has arisen lately in the business world by movements like occupy Wall Street, or more concerning economic crises started in 2008. Due to this pressure, companies have to be more careful and act more responsibly. In the recent years, Corporate Social Responsibility (CSR) has been seen like a panacea of all stakeholders problems, more and more reports of CSR being published on companies website. However, it has been proven that just to claim actions of social responsibility, does not mean those companies are truly responsible. As expected, this behavior is penalized by a part of stakeholders. In this context, for each firm is important to know which are the most representative stakeholders, and how a certain situation could affect this scale. For explaining this fact, this paper analyzes the case of Brent Spar, pointing how an industrial giant like Shell, using a wrong CSR policy, could lose both money and image capital. In order to do that, in the first part is discussed the CSR from the perspective of stakeholder theory. Although it is present since 1950s in the United States of America and evolved all over the world like an all known concept, CSR does not have yet an universally accepted definition. Therefore, in this article was stated a definition for CSR from the stakeholder theory approach, in order to understand the Brent Spar actions and implications. In the second part of the paper are analyzed the steps taken by both sides, on one hand by Shell and on the other, by some of the stakeholders. The actions have been explained from the CSR paradigm perspective. Finally, it is proved why Brent Spar is a case of CSR failed, and how, by neglecting of some stakeholders categories, a company could pay important costs. Moreover, the paper demonstrates that the image of one company, from a specific area, could affect the all industry field. Therefore, a proper identification of key stakeholders, a good communication with those and flexibility in decision, could be the success factors for companies, and may lead to successful CSR. Correct CSR actions become an imperative in nowadays industrial scenario, being viewed as a change imposed by globalization and by the transnational nature of CSR.
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L. Prikler, G. Bán, M. Kizilcay, G. Tari, A. Tombor, and J. Zerenyi. "Influence of the Secondary Arc on the Operation of Single Phase Autoreclosure of the 400 kV interconnection between Hungary and Croatia." Journal of Energy - Energija 59, no. 1-4 (2022): 61–69. http://dx.doi.org/10.37798/2010591-4279.
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 Sažetak: Faults on EHV lines are generally single-phase-to-ground ones and not permanent in the majority of cases. Thus single phase auto reclosure (SPAR), at which the faulty phases are tripped for a short time, eliminates the predominant part of the faults [1,2]. The secondary arc, which follows the high power arc after tripping the faulty phases at both side of the line may endanger the successfulness of reclosing if the duration of the switched off interval (dead time) is not long enough to ensure the extinction of the arc. The secondary arcing times recorded on different EHV lines or measured in laboratory tests show significant spread, consequently, to select a dead time according to the longest experimental secondary arc extinction time is not feasible. During commissioning of the double circuit 420 kV interconnection between Hungary and Croatia several staged faults were initiated to analyze the arc extinction performance. Initially the line was in operation by connecting the two circuits in parallel along the 1/3rd of the full length. In this configuration the longest secondary arc extinction time was 4 seconds and the secondary arc has not extinguished in 27s in one of the tests, so the line had to be tripped out to clear the staged fault. Later on, the length of the Croatian section of the line has been significantly shortened after putting a new substation into service. The increased performance of SPAR of the new arrangement has been proved with field tests. A realistic representation of the secondary arcs is essential in determining the auto-reclosure performance of EHV transmission lines. As shown in the paper, the random variation of the arc parameters influences significantly the arc extinction time. The results of the field tests confirmed the importance of the distributed nature of the transmission line and the nonlinear characteristic of the arc resistance in the intermittent region of arcing, where temporary extinctions and sudden re-ignitions in the arc channel produce transient wave processes along the line.
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Stamoulis, Konstantinos, Dimitrios Panagiotopoulos, George Pantazopoulos, and Spyros Papaefthymiou. "Failure analysis of an aluminum extrusion aircraft wing component." International Journal of Structural Integrity 7, no. 6 (2016): 748–61. http://dx.doi.org/10.1108/ijsi-10-2015-0050.
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Purpose The purpose of this paper is to deal with the failure analysis of a fractured spar stiffener, extruded from 7075-T6 aluminum alloy, which was found in the central wing, trailing edge structure of a military transport aircraft. The previous loading history and the dominant environmental factors (corrosive and humid atmosphere, water entrapment, etc.) suggest corrosion and fatigue as the principal failure modes, synergistically acting on the wing component. Design/methodology/approach This study presents the failure analysis concentrated on finding evidence of failure mechanisms and plausible root-cause(s) of the fractured spar stiffener. Chemical analysis, stereo and scanning electron microscopy, as well as finite element analysis employed as the main analytical tools for material characterization and failure investigation. Findings The overall evaluation of the findings suggest that the failure caused by a synergy of two mechanisms; a crack initiated in the longitudinal, extrusion direction by an environmentally assisted corrosion attack, then propagated by the superimposed transverse stress field, branched/deflected due to a low crack driving force and extended in a transverse path through a high cycle fatigue process. Finally, the complete fracture occurred as fast fracture, resulted by a ductile overload. Originality/value This paper deals with an industrial damage case study, providing analysis and modeling from structural engineering standpoint. The aforementioned findings concerning the fractured aircraft component allow gaining a deeper knowledge about the mechanisms of crack initiation and propagation which, in turn, can produce a valuable feedback to design, inspection and maintenance procedures. This includes a modified heat treatment from T6 to T73 temper for the redesigned component.
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Wang, Yue, Jianzheng Shi, Terence T. Ow, Jia Yun, and Yuanyu Yang. "The Impact of Technological Innovations on Consumer Behavior in E-Commerce." Journal of Organizational and End User Computing 37, no. 1 (2025): 1–27. https://doi.org/10.4018/joeuc.372896.
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This study systematically reviews the literature on the impact of technological innovations in e-commerce on consumer behavior, using the SPAR-4-SLR methodology and TCCM framework. It consolidates research across various technologies, including websites, social media, live streaming, AR/VR, and AI. The analysis reveals a growing interest in this field post-2017, with a focus on websites and social media, but highlights a research gap in emerging technologies. Key theoretical frameworks are identified, emphasizing the need for integration to comprehensively understand consumer behavior. The review maps out antecedents, mediators, moderators, and outcomes, stressing the importance of longitudinal studies and advanced analytics. This approach aims to bridge research gaps and suggest future directions, enhancing theoretical and practical understanding of e-commerce technological innovations, and contributing to a more dynamic and consumer-centric e-commerce ecosystem.
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Khan, Fateh Mohd, and Mohammad Khalid Azam. "Chatbots in hospitality and tourism: a bibliometric synthesis of evidence." Journal of the Academy of Business and Emerging Markets 3, no. 2 (2023): 29–40. https://doi.org/10.5281/zenodo.10183134.
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Chatbots are now widely used in the hospitality industry because they offer round-the-clock support, engage clients in human-like dialogue, and lighten the workload of human agents. However, despite being a relevant technology, scholarly research on the application of chatbots in Hospitality and Tourism remains scant and dispersed. The present review employs a bibliometric review approach to synthesize this domain and identify relevant research lines for future academics. This study uses a mixed review methodology that combines the SPAR-4-SLR protocol and bibliometric tools. Using the Scopus database, the authors compiled 164 articles about chatbots in hospitality and tourism research. The data were examined using Vosviewer, Bibliometrix-R and MS-Excel. This review, which tries to comprehend the changes in this domain over the last eight years in terms of prolific writers, most prominent journals, significant issues, and the field's intellectual and social structure, serves as the foundation for research on chatbots in hospitality and tourism. The findings indicate that this field is still in its infancy. To aid researchers in advancing this field of study, this review aims to offer deeper insights for the pursuance of future research.
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Li, Hui, Xiaolong Lu, Wen Xin, et al. "Repair Parameter Design of Outer Reinforcement Layers of Offshore Wind Turbine Blade Spar Cap Based on Structural and Aerodynamic Analysis." Energies 16, no. 2 (2023): 712. http://dx.doi.org/10.3390/en16020712.
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The influence of the outer reinforcement layers on the repair structure and aerodynamic performance was studied. Firstly, a continuous damage mechanics model was established, and the 3D Hashin criterion and cohesive zone material model were used to analyze the damage repair model. The failure load deviation was 5.5%. Secondly, on the basis of the transition model and SST–ω turbulence model, the aerodynamic analysis model of DU300 airfoil was established. The numerical simulation results showed that the lift coefficient and pressure distribution at the angle of attack of 10° and 15° were deviated from the experimental values by 2%. Furthermore, 27 structural repair models, nine 2D aerodynamic repair models, and a 3D full-scale blade model were designed. It was found that, when the repair length accounted for 60% of the total model length, the failure load increased by 22%, but the aerodynamic power with the repair length of 10 m was decreased by 0.137%. When the repair area was large and the repair height was from 4 mm to 6 mm, the failure load was greatly increased by about 30%, and the aerodynamic pressure distribution and static pressure field fluctuated significantly. The results show that the structural and aerodynamic characteristics were closely related to the repair parameters.
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Xia, Jinzhu. "Development planning of deepwater gas fields: the application of floating production platforms." APPEA Journal 54, no. 2 (2014): 512. http://dx.doi.org/10.1071/aj13085.
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Producing North West Australia (NWA) deepwater hydrocarbon reserves, particularly gas reserves to LNG plants, poses unique challenges. These include extreme metocean conditions, unique geotechnical conditions, long distances to infrastructure and LNG plants, as well as high reliability/availability of supply. This extended abstract addresses important technical, commercial, and regulatory factors that drive the field development planning, including the selection of suitable production facilities for these deepwater hydrocarbon developments off NWA. While all-subsea developments have been an inspiration for offshore engineers for a few decades, subsea gas compression, dehydration, power supply, and control are still technically and commercially demanding, especially for long distance tie-backs. Subsea well intervention and facility maintenance requirements also favour the application of dedicated floating platforms. A wet or dry-tree floating production platform, therefore, is required in most cases. Whereas Semisubmersible, TLP, Spar, FPSO, and FLNG (or LNG FPSO) designs all have the attributes to be a host gas production facility or a part of a production system, only oil FPSOs have been installed in this region to date. Linkages between key reservoir and fluid characteristics and surface facility functionalities are discussed in this extended abstract. Advantages and disadvantages of various platform designs are compared. A focus is on the influence of regional drivers and site characteristics, in particular, metocean and geotechnical conditions and remoteness of the NWA fields. The differentiation between oil and gas developments are addressed. It is emphasised that platform applicability and compatibility should be assessed in the context of field development planning for individual projects to achieve optimum risked life cycle financial values.
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Bagaiskov, Yu S. "Multi-Purpose Porous Ceramic Material." Materials Science Forum 931 (September 2018): 594–97. http://dx.doi.org/10.4028/www.scientific.net/msf.931.594.
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The main criteria for evaluation of ceramic products’ properties are strength, structural and mechanical, and thermophysical properties. To produce ceramic composites with a wide range of structural, mechanical, strength, and performance properties depending on application, various additives (flux agents, sintering agents, fillers) and heat treatment processes are used. Studies to determine a rational mixture composition have been carried out. A multipurpose material, comprising particles of the basic chamotte filler (burned clay) with a bonding agent in the form of refractory clay from the Latnenskoye deposit with a field spar fluxing agent, an additional filler made of heat-resistant silicon carbide, and an adhesive component in the form of powdered dextrin, is suggested. According to the combination of its ensured parameters, the obtained ceramic material can be multipurpose. Its degree of porosity and permeability make the material filtering, sound-proofing, and heat-retaining; considering the low density, it can be used as a lightweight construction material.
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Zippa, Elena, Ivan Bragin, George Chelnokov, and Natalia Kharitonova. "The Annenskiy thermal waters as the certain stage of the water-rock interaction (Far East, Russia)." E3S Web of Conferences 98 (2019): 01054. http://dx.doi.org/10.1051/e3sconf/20199801054.
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Chemical composition and saturation degree of the Annenskiy thermal waters to minerals of water-bearing rock have been considered in the manuscript. It is shown that the thermal waters are low mineralized, alkaline and belong to HCO3-Na type. The thermal waters-rock system is equilibrium-nonequilibrium. It means that the waters dissolve primary minerals continuously, never reaching saturation (anorthite, K-field spar and etc.), and form new secondary mineral phases simultaneously, reaching saturation (gibbsite, montmorillonite, albite and etc.). Besides, peculiarities of the equilibrium with minerals of water-bearing rocks for surface and ground waters of the studied region was considered. It is established that the thermal waters are ahead of surface and ground waters and represent the certain stage of the water-rock system evolution. The stage is characterized by the certain chemical composition (TDS=148-317 mg/L, HCO3-Na, SiO2=9-80 mg/L), complex of secondary minerals (calcite, albite, laumontite and etc.) and special geochemical environment (pH 8.2-8.6).
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Thode, Aaron M. "Abandon FLIP! The following being a completely unembellished and sober account of a disastrous field experiment with Doug Cato, with side comments on his subtle influences on bioacoustic animal tracking." Journal of the Acoustical Society of America 154, no. 4_supplement (2023): A89. http://dx.doi.org/10.1121/10.0022895.
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I have only been to sea once with Doug Cato, as a graduate student. It did not end well. In 1996 the R/P FLIP, a manned spar buoy, was deployed off the coast of San Diego to test advanced passive acoustic tracking methods on baleen whales, with Doug along as an invited guest. He had long been interested in acoustic means of localizing whales and was one of the first scientists to suggest using relative differences between received levels on hydrophones (instead of just the relative timing) for fixing an animal call’s location [JASA 104(3), 1667–1678]. This idea is the fundamental basis behind “matched-field processing” (MFP), the technique behind the FLIP test. The trip was supposed to collect three weeks of data; instead, it collected 42 h. This presentation will explain the challenges of abandoning a vessel at sea, and why garbage scows are underappreciated. It will also explain my brief involvement in Mike Noad’s and Doug Cato’s HARC field experiment as part of another MFP demonstration, and why that did not end very well either. Interlaced with these tales of disaster is a review of how Doug’s thoughts on animal tracking have re-emerged under a variety of circumstances, especially in arctic bioacoustics.
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Alber, J., L. Assfalg, C. N. Nayeri, et al. "3D printed rotor blades for a research wind turbine: Aerodynamic and structural design and testing." Journal of Physics: Conference Series 2265, no. 4 (2022): 042070. http://dx.doi.org/10.1088/1742-6596/2265/4/042070.
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Abstract This study combines the design, the 3D printing and the testing of a small 3-bladed wind turbine rotor for research and teaching purposes. The objective is the additive manufacturing of a rotor with a radius of one meter, as an alternative to subtractive methods, such as computerized milling. The blade design is developed using freely available software packages. The aerodynamic considerations include the airfoil selection, the calculation of the blade geometry and the simulation of the ultimate load cases. The structural considerations are focussed on the printable materials, the infill structures and the retrofit of a load-carrying spar. The rotor blades are 3D printed with the BigRep One at the maker space of the TH Wildau. The structural integrity of the prototype blade is tested in terms of the ultimate root bending moments and the centrifugal forces at the HTW Berlin. The aerodynamic run-up tests are performed at the large wind tunnel of the TU Berlin measuring the power curves. The successful prototype paves the way for follow-up projects, such as open field tests and the 3D printing of larger rotor blades.
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Henselová, M., M. Regecová, and A. Sováková. "Isolation of chloroplasts in the Karwinskia species and determination of their photochemical activity under in vitro conditions." Plant, Soil and Environment 50, No. 4 (2011): 149–56. http://dx.doi.org/10.17221/4075-pse.
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Reaction conditions for evaluation of the photochemical activity of isolated chloroplasts in the Hill reaction of Karwinskia humboldtiana (Roem &amp; Schut) Zucc. and Karwinskia parvifolia Rose species were determined. Hill&rsquo;s reaction activity was measured spectrophotometrically at 630 nm as the amount of DCPIP reduction by the chloroplast suspension at an irradiance of 400 &micro;mol/m<sup>2</sup>/sPAR. A significant difference was observed between the activity of chloroplasts isolated at 2&deg;C and 25&deg;C amounting to 27% in Karwinskia humboldtiana and 18.5% in K. parvifolia. After 24 hours of storage of chloroplasts at a suspension of 2&deg;C, a significant decrease of chloroplasts activity was noted in both species, e.g. 38% in Karwinskia humboldtiana and 45% in K. parvifolia. The photochemical activity of chloroplasts increased also with the length of irradiation of the reaction mixture and the content of chlorophyll (a + b) in chloroplast suspension. The activity of chloroplasts was found to be significantly higher in the species K. humboldtiana than in K. parvifolia and it proved higher in both when these were grown under field conditions rather than in a greenhouse.
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Raman, Venkadesh, Monssef Drissi-Habti, Preshit Limje, and Aghiad Khadour. "Finer SHM-Coverage of Inter-Plies and Bondings in Smart Composite by Dual Sinusoidal Placed Distributed Optical Fiber Sensors." Sensors 19, no. 3 (2019): 742. http://dx.doi.org/10.3390/s19030742.
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Designing of new generation offshore wind turbine blades is a great challenge as size of blades are getting larger (typically larger than 100 m). Structural Health Monitoring (SHM), which uses embedded Fiber Optics Sensors (FOSs), is incorporated in critical stressed zones such as trailing edges and spar webs. When FOS are embedded within composites, a ‘penny shape’ region of resin concentration is formed around the section of FOS. The size of so-formed defects are depending on diameter of the FOS. Penny shape defects depend of FOS diameter. Consequently, care must be given to embed in composites reliable sensors that are as small as possible. The way of FOS placement within composite plies is the second critical issue. Previous research work done in this field (1) investigated multiple linear FOS and sinusoidal FOS placement, as well. The authors pointed out that better structural coverage of the critical zones needs some new concepts. Therefore, further advancement is proposed in the current article with novel FOS placement (anti-phasic sinusoidal FOS placement), so as to cover more critical area and sense multi-directional strains, when the wind blade is in-use. The efficiency of the new positioning is proven by numerical and experimental study.
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Dovbush, Т. I., L. M. Stepaniuk, О. V. Ziultsle, and Т. B. Yaskevych. "Uranium-Lead by Monacite Geochronology of Granites Distributed in the Middle Current of ihe River Ros (Ros-Tikich Megablock Ukrainian Shield)." Geochemistry and ore formation, no. 42 (2021): 89–93. http://dx.doi.org/10.15407/gof.2021.42.089.
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Granitoids play a leading role in the geological structure of the Ros-Tikich megablock. The rocks of the Ros-Tikich series, which form the supercrystalline base here, have survived among the granitoids only in the form of some remnants of different sizes. In the coastal outcrops of the middle course of the river Ros (east of Bila Tserkva) and in the quarries located near the river, the most common are two-feldspar granitoids, isolated as part of two complexes – Uman and Stavyshche. Plagiogranitoids and supercrustal rocks have survived among them in the form of separate fragments. Of the accessory uranium-containing minerals, zircon and titanite are present in two-field spar granites, and monazite was found in single samples of granites in which titanite was absent. The age of obscure porphyry-like granite discovered by the Ostrivsk quarry – 2063.5 ± 1.2 million years and uniformgrained granite, distributed in the quarry of the village of Bovkun – 2042.5 ± 8.6 million years. The obtained values of the isotopic age of these granites are in good agreement with the results of uranium-lead isotopic dating of zircons from twofeldspar granites of the Ros-Tikich megablock (1990-2080 million years). This allows us to propose to combine the granites of the Stavyshche and Uman complexes into one Paleoproterozoic complex.
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Camarena, Ernesto, Evan Anderson, Josh Paquette, Pietro Bortolotti, Roland Feil, and Nick Johnson. "Land-based wind turbines with flexible rail-transportable blades – Part 2: 3D finite element design optimization of the rotor blades." Wind Energy Science 7, no. 1 (2022): 19–35. http://dx.doi.org/10.5194/wes-7-19-2022.
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Abstract. Increasing growth in land-based wind turbine blades to enable higher machine capacities and capacity factors is creating challenges in design, manufacturing, logistics, and operation. Enabling further blade growth will require technology innovation. An emerging solution to overcome logistics constraints is to segment the blades spanwise and chordwise, which is effective, but the additional field-assembled joints result in added mass and loads, as well as increased reliability concerns in operation. An alternative to this methodology is to design slender flexible blades that can be shipped on rail lines by flexing during transport. However, the increased flexibility is challenging to accommodate with a typical glass-fiber, upwind design. In a two-part paper series, several design options are evaluated to enable slender flexible blades: downwind machines, optimized carbon fiber, and active aerodynamic controls. Part 1 presents the system-level optimization of the rotor variants as compared to conventional and segmented baselines, with a low-fidelity representation of the blades. The present work, Part 2, supplements the system-level optimization in Part 1 with high-fidelity blade structural optimization to ensure that the designs are at feasible optima with respect to material strength and fatigue limits, as well as global stability and structural dynamics constraints. To accommodate the requirements of the design process, a new version of the Numerical Manufacturing And Design (NuMAD) code has been developed and released. The code now supports laminate-level blade optimization and an interface to the International Energy Agency Wind Task 37 blade ontology. Transporting long, flexible blades via controlled flapwise bending is found to be a viable approach for blades of up to 100 m. The results confirm that blade mass can be substantially reduced by going either to a downwind design or to a highly coned and tilted upwind design. A discussion of active and inactive constraints consisting of material rupture, fatigue damage, buckling, deflection, and resonant frequencies is presented. An analysis of driving load cases revealed that the downwind designs are dominated by loads from sudden, abrupt events like gusts rather than fatigue. Finally, an analysis of carbon fiber spar caps for downwind machines finds that, compared to typical carbon fibers, the use of a new heavy-tow carbon fiber in the spar caps is found to yield between 9 % and 13 % cost savings.
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Elshan Aliyev, Marat Huseynov, and Hilal Tahirli Tarana Aghadiyeva. "IRRADIATION OF CARBON DIOXIDE WITH A VACUUM UV SOURCE AND OBTAINING OF STRATOSPHERIC OZONE." ETM - Equipment, Technologies, Materials 13, no. 01 (2023): 150–55. http://dx.doi.org/10.36962/etm13012023-150.
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It has been known for more than 100 years that carbon dioxide absorbs photons in the ultraviolet and infrared ranges of radiation, creating a greenhouse effect. However, so far no one has answered the question: what is a photon? It is known that a photon has corpuscular and wave properties, has a certain pressure. An interesting experiment was carried out when a photon was dissected using Wilson chamber and it left traces of the opposite sign. The correct conclusion was made that one trace in the Wilson chamber was left by an electron, and the other - by a positron. There were other experiments, for example: birefringence of light in quartz crystals, Icelandic spar, etc., but there were no correct conclusions made about what a photon is. A photon is an electric dipole, consisting of an electron and a positron charges, without a spin charge-conjugate formation, which has a dipole magnetic field. Carbon dioxide, absorbing photons with a mass of 18.210-31 kg, being structured in the core, turns into triatomic oxygen, that is, into stratospheric ozone. A photon absorbs only a carbon atom that has an excess of spins. Photons absorbed by carbon dioxide (electric dipoles) having a magnetic field interact with the magnetic force lines of the dipole magnetic field of the Earth, and as a result of such interaction, triatomic oxygen-ozone moves into the stratosphere. Stratospheric ozone is not explosive in all aggregate states and at high pressures. In the atmosphere, it enters into a nuclear interaction with neutrons emanating from the sources of future earthquakes, forming water. So, naturally, the ozone layer of the Earth is depleted, replenishing the hydrosphere. Irradiation of CO2 and production of stratospheric ozone is a solution to the problem of climate warming. Stratospheric ozone can be widely used in the defense industry. An airship filled with stratospheric ozone will be much more efficient than airships filled with hydrogen or helium. The production of stratospheric ozone from carbon dioxide is a fundamental discovery in the field of photonuclear physics. Key words: electric dipole, photon, carbon dioxide, stratospheric ozone, photonuclear reaction.
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Tung, Aaron. "Co-creation of knowledge – an effective mechanism for managing decommissioning stakeholders." APPEA Journal 61, no. 1 (2021): 48. http://dx.doi.org/10.1071/aj20026.
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Despite the fact that it has been 26 years since the events of Brent Spar, stakeholder impacts are still continuing to affect the performance of oil and gas decommissioning projects. If stakeholders are not well managed, not only can they have devastating consequences on project costs and schedules, but there may also be further social and environmental implications as well. On the flip side, if organisations can get it right, stakeholders can also bring about various benefits. An ongoing research project to enhance project managers’ understanding of the United Kingdom and Australian decommissioning landscapes found that knowledge creation through interactions between organisations and stakeholders has brought about benefits to various decommissioning projects, including the Maureen, Miller, and Brae decommissioning projects. The concept of co-creation of knowledge has been mentioned in many academic works to be an effective mechanism for managing stakeholders in the field of sustainable development, product development, and healthcare. However, the explicit links between co-creation of knowledge and decommissioning have yet to be drawn. This article proposes that co-creation of knowledge be adopted as a best practice to manage decommissioning stakeholders. By actively co-creating knowledge with stakeholders and extending the existing body of knowledge in decommissioning, the extent of alignment and trust between organisations and stakeholders are strengthened, creating long-term relationships that greatly improves the probability of stakeholder acceptance and approval.
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BURTAN, Lavinia, Nicoleta MĂRIN, Oana Daniela BADEA, and Nicolaie IONESCU. "THE NEED FOR CHALKING AND CHEMICAL FERTILIZERS APPLICATION ON THE ALBOTA ALBIC LUVISOL." "Annals of the University of Craiova - Agriculture Montanology Cadastre Series " 52, no. 1 (2022): 67–72. http://dx.doi.org/10.52846/aamc.v52i1.1315.
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A field experiment was carried out at SCDA Pitești, on an Albic Luvisol with a 25.0-25.2% clay content, with soy crop, Raluca TD variety. Seeds were treated with Bradyrhizobiumjaponicum, the density was 45-50 germinable grains/m2, and the distance between rows 50 cm. Fertilizers were applied during the vegetation cycle as follows: Dual 1 liter/ha, Décor 0,5 liters/ha, and Pulsar 1 liter/ha. The experimental design included 12 variants with the following chemical fertilizers doses: N0P0, N40P40, and N80P80. Agrocalcium (a product obtained by lime fine grinding, with a minimum 90% calcium carbonate content) and Doloflor (100% BIO fertilizer based on bitter spar with a minimum 50% calcium and magnesium oxide content) were used as chalking. Doloflor application as powder and granules in a 2.5 t/ha dose without N and P fertilization modified the soil reaction and pH registered values of 5.3-5.5, in the moderately acid reaction domain. Doloflor powder and granules in 2.5 t/ha dose together with N40P40 and N80P80 fertilizers doses determined very high mobile phosphorus content values (95-97 mg/kg). Mobile potassium contents in the analyzed variants are low ((100-125 mg/kg). Grain yield ranged from 1,483 to 2,053 kg/ha. The lowest yield resulted in the unfertilized and unlimed control. The highest values of grain yield were obtained when applying liming doses together with complex fertilizers.
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Володимир Володимирович Ванін, Генадій Анатолійович Вірченко, and Олександр Васильович Збруцький. "COMPUTER STRUCTURAL-PARAMETRIC GEOMETRIC MODELS AS A TOOL FOR DESIGN-TECHNOLOGIC OPTIMIZATION OF AIRPLANE." MECHANICS OF GYROSCOPIC SYSTEMS, no. 27 (October 6, 2014): 111–19. http://dx.doi.org/10.20535/0203-377127201438465.
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The current stage of technical progress is characterized by the extensive use of computer information technology in the creation of various industrial products. Therefore, the development and introduction of new effective methods, techniques and algorithms for computer-aided design are relevant today.It is known that the system consisting of the optimal elements itself is not necessarily the same. Therefore, complex optimization is very important for the designed technical objects.Geometric models have a special place in integrating for computational models of technical objects because significant number of output characteristics substantially depend on geometrical parameters.The applications of structural-parametric geometric modeling methodology for design-technologic optimization of technical products are analyzed in this article. Variant engineering design was shown on the example of spar of airplane wing. Basic techniques of proposed method were presented. The emphasis was placed on their universal and invariant character for different objects and processes.Prospects for further development of this scientific field studies on the spread of its practical application to optimal designing of different industrial products were considered.The main advantages of the analyzed computer-integrated engineering and process design of industrial products based on the use of structural-parametric geometric models is the universality and invariance of the proposed techniques for different objects and processes.Featured approach provides a flexible and productive implementation of complex optimization of industrial products. This direction of creation of technical products requires further intensive research for its successful practical realization.
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Ciasullo, Maria Vincenza, Weng Marc Lim, Mohammad Fakhar Manesh, and Rocco Palumbo. "The patient as a prosumer of healthcare: insights from a bibliometric-interpretive review." Journal of Health Organization and Management 36, no. 9 (2022): 133–57. http://dx.doi.org/10.1108/jhom-11-2021-0401.
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PurposeHealthcare policies around the globe are aimed at achieving patient-centeredness. The patient is understood as a prosumer of healthcare, wherein healthcare service co-production and value co-creation take center stage. The article endeavors to unpack the state of the literature on the innovations promoting the transition toward patient-centeredness, informing policy and management interventions fostering the reconceptualization of the patient as a prosumer of healthcare services.Design/methodology/approachA hybrid review methodology consisting of a bibliometric-interpretive review following the Scientific Procedures and Rationales for Systematic Literature Reviews (SPAR-4-SLR) protocol is used. The bibliometric component enabled us to objectively map the extant scientific knowledge into research streams, whereas the interpretive component facilitated the critical analysis of research streams.FindingsPatient-centeredness relies on a bundle of innovations that are enacted through a cycle of patients' activation, empowerment, involvement and engagement, wherein the omission of any steps arrests the transition toward service co-production and value co-creation. Institutional, organizational and cognitive barriers should be overcome to boost the transition of patients from consumers to prosumers in a patient-centered model of healthcare.Originality/valueThe article delivers the state of the art of the scientific literature in the field of innovations aimed at sustaining the transition toward patient-centeredness and provides some food for thoughts to scholars and practitioners who wish to push forward service co-production and value co-creation in healthcare.