A knowledge system to support manufacturing knowledge during preliminary design

The integration of manufacturing knowledge into the product introduction process is presented as a knowledge management problem. Concurrent engineering techniques are highly effective in sharing manufacturing knowledge, particularly for the re-use of knowledge at the detail design stage when the geometry has been developed. This research considers the use of manufacturing knowledge in the earlier, preliminary stage of design where the geometry is not so developed and where development of manufacturing technology may be required. An exploratory case study was carried out with a manufacturer of gas turbine engines for the civil aviation market. Semi-structured interviews were carried out to investigate the manufacturing knowledge required and its format. Using a data-driven analysis, a thematic code was developed and three themes emerged: manufacturing impact, expressions of impact and knowledge type. These themes indicate the requirement for a hybrid social-technical system to support both the tacit and explicit elements of manufacturing knowledge. An indication of the maturity of the manufacturing process also emerged as a major requirement in order to synchronize manufacturing technology developments with future product requirements. A prototype knowledge system is now being developed to meet the requirements identified through the coding analysis. The specification of the system, which uses a combination of information and social systems, is discussed

Optical techniques for 3D surface reconstruction in computer-assisted laparoscopic surgery

One of the main challenges for computer-assisted surgery (CAS) is to determine the intra-opera- tive morphology and motion of soft-tissues. This information is prerequisite to the registration of multi-modal patient-specific data for enhancing the surgeon’s navigation capabilites by observ- ing beyond exposed tissue surfaces and for providing intelligent control of robotic-assisted in- struments. In minimally invasive surgery (MIS), optical techniques are an increasingly attractive approach for in vivo 3D reconstruction of the soft-tissue surface geometry. This paper reviews the state-of-the-art methods for optical intra-operative 3D reconstruction in laparoscopic surgery and discusses the technical challenges and future perspectives towards clinical translation. With the recent paradigm shift of surgical practice towards MIS and new developments in 3D opti- cal imaging, this is a timely discussion about technologies that could facilitate complex CAS procedures in dynamic and deformable anatomical regions

Timing of uplift and evolution of the Lüliang Mountains, North China Craton

This study analyses evidence for reformed basin development and basin-mountain coupling associated with development of the Ordos Basin and the Lüliang Mountains, China. Gaining an improved understanding of the timing and nature of uplift and evolution of the Lüliang Mountains is important for the reconstruction of the eastern sedimentary boundary of the Ordos Basin (a major petroliferous basin) as well as for providing insight into the evolution and breakup of the North China Craton (NCC). Based on systematic sampling for fission track analysis, it is suggested that the main phase of uplift of the Lüliang Mountains occurred since later part of the Early Cretaceous. Three evolutionary stages of uplift and development are identified: slow initial uplift (120–65 Ma), accelerated uplift (65–23 Ma), and intensive uplift (23 Ma to present), with the majority of the uplift activity having occurred during the Cenozoic. The history of uplift is non-equilibrium and exhibits complexity in temporal and spatial aspects. The middle and northern parts of the Lüliang Mountains were uplifted earlier than the southern part. The most intensive episode of uplift activity commenced in the Miocene and was associated with a genetic coupling relationship with the eastern neighboring Cenozoic Shanxi Grabens. The uplifting and evolutionary processes of the Lüliang Mountains area since later part of the Early Cretaceous share a unified regional geodynamic setting, which was accompanied by uplift of the Mesozoic Ordos Basin and development of the neighboring Cenozoic Shanxi Grabens. Collectively, this regional orogenic activity is related principally to the far-field effects of both the compression sourced from the southwestern Tibet Plateau and westward subduction of the Pacific Plate in Cenozoic

Turkey research, 1966

The Ohio poultry industry / R. E. Cook -- Lighting turkeys for maximum reproductive performance / K. I. Brown -- Feeding the breeder turkey / S. P. Touchburn -- A comparison of methods for artificially inseminating turkeys / K. e. Nestor and K. I. Brown -- Broody management and egg production of turkeys / P. A. Renner and K. E. Nestor -- Egg quality and hatchability in turkeys / K. E. Nestor -- Importance of female sex hormones in the reproductive performance of turkey hens / D. P. Bajpayee and K. I. Brown -- Some factors affecting storage of turkey semen / K. I. Brown -- Feeding schedules for growing turkeys / S. P. Touchburn and V. D. Chamberlain -- Determining selling age of turkeys by returns over feed costs / R. L. Baker -- Effects of age of turkeys on the flavor of turkey meat / G. J. Mountney -- Early poult mortality / K. E. Nestor and P. A. Renner -- Airsacculitis in turkeys / Y. S. Mohamed and E. H. Bohl -- Some observations on wing notching of turkeys / V. D. Chamberlain -- Turkeys selected for resistance to stress / K. I. Brown -- Genetics of growth and reproduction / K. E. Nesto

Attosecond Delays in X-ray Molecular Ionization

The photoelectric effect is not truly instantaneous, but exhibits attosecond delays that can reveal complex molecular dynamics. Sub-femtosecond duration light pulses provide the requisite tools to resolve the dynamics of photoionization. Accordingly, the past decade has produced a large volume of work on photoionization delays following single photon absorption of an extreme ultraviolet (XUV) photon. However, the measurement of time-resolved core-level photoionization remained out of reach. The required x-ray photon energies needed for core-level photoionization were not available with attosecond tabletop sources. We have now measured the x-ray photoemission delay of core-level electrons, and here report unexpectedly large delays, ranging up to 700 attoseconds in NO near the oxygen K-shell threshold. These measurements exploit attosecond soft x-ray pulses from a free-electron laser (XFEL) to scan across the entire region near the K-shell threshold. Furthermore, we find the delay spectrum is richly modulated, suggesting several contributions including transient trapping of the photoelectron due to shape resonances, collisions with the Auger-Meitner electron that is emitted in the rapid non-radiative relaxation of the molecule, and multi-electron scattering effects. The results demonstrate how x-ray attosecond experiments, supported by comprehensive theoretical modelling, can unravel the complex correlated dynamics of core-level photoionization

Characterization of a fluvial aquifer at a range of depths and scales: the Triassic St Bees Sandstone Formation, Cumbria, UK

Fluvial sedimentary successions represent porous media that host groundwater and geothermal resources. Additionally, they overlie crystalline rocks hosting nuclear waste repositories in rift settings. The permeability characteristics of an arenaceous fluvial succession, the Triassic St Bees Sandstone Formation in England (UK), are described, from core-plug to well-test scale up to ~1 km depth. Within such lithified successions, dissolution associated with the circulation of meteoric water results in increased permeability (K~10−1–100 m/day) to depths of at least 150 m below ground level (BGL) in aquifer systems that are subject to rapid groundwater circulation. Thus, contaminant transport is likely to occur at relatively high rates. In a deeper investigation (> 150 m depth), where the aquifer has not been subjected to rapid groundwater circulation, well-test-scale hydraulic conductivity is lower, decreasing from K~10−2 m/day at 150–400 m BGL to 10−3 m/day down-dip at ~1 km BGL, where the pore fluid is hypersaline. Here, pore-scale permeability becomes progressively dominant with increasing lithostatic load. Notably, this work investigates a sandstone aquifer of fluvial origin at investigation depths consistent with highly enthalpy geothermal reservoirs (~0.7–1.1 km). At such depths, intergranular flow dominates in unfaulted areas with only minor contribution by bedding plane fractures. However, extensional faults represent preferential flow pathways, due to presence of high connective open fractures. Therefore, such faults may (1) drive nuclear waste contaminants towards the highly permeable shallow (< 150 m BGL) zone of the aquifer, and (2) influence fluid recovery in geothermal fields

Discovertebral (Andersson) lesions of the spine in ankylosing spondylitis revisited

A well-known complication in patients with ankylosing spondylitis (AS) is the development of localised vertebral or discovertebral lesions of the spine, which was first described by Andersson in 1937. Since then, many different terms are used in literature to refer to these localised lesions of the spine, including the eponym ‘Andersson lesion’ (AL). The use of different terms reflects an ongoing debate on the exact aetiology of the AL. In the current study, we performed an extensive review of the literature in order to align communication on aetiology, diagnosis and management between treating physicians. AL may result from inflammation or (stress-) fractures of the complete ankylosed spine. There is no evidence for an infectious origin. Regardless of the exact aetiology, a final common pathway exists, in which mechanical stresses prevent the lesion from fusion and provoke the development of pseudarthrosis. The diagnosis of AL is established on conventional radiography, but computed tomography and magnetic resonance imaging both provide additional information. There is no indication for a diagnostic biopsy. Surgical instrumentation and fusion is considered the principle management in symptomatic AL that fails to resolve from a conservative treatment. We advise to use the term Andersson lesion for these spinal lesions in patients with AS

Quantitative characterization of the sedimentary architecture of Gilbert-type deltas

Steep-fronted Gilbert-type deltas are common features of tectonically active settings, as well as of physiographic settings where accommodation is dictated by landforms with steeply inclined margins, such as incised valleys, fjords, and proglacial lakes. Existing facies models for Gilbert-type deltas are largely qualitative; this study presents a quantitative analysis of the variability in facies architectures of such deltas. A database approach is used to characterize the preserved sedimentary architecture of 62 Gilbert-type deltas of Cretaceous to Holocene ages developed in various basin settings worldwide. Data on 706 architectural elements and 12,872 facies units are used to develop quantitative facies models that describe the variability in architecture and facies of Gilbert-type deltas at multiple scales of observation, and to account for the possible controls exerted by allogenic and autogenic factors. The analysed data reveal high variability in the geometry and facies of Gilbert-type deltas. The thickness of the examined deltas varies from 2 to 650 m, yet positive scaling between delta thickness and length is consistently recognized across the studied examples, which is interpreted in terms of relationships between accommodation, sediment supply and delta lifespan. Based on their facies character, the deltas are classified into gravel- and sand-dominated types, with contrasting facies organizations of topset, forest and bottomset elements, and by different relationships between facies and dimensions; yet, both types exhibit significant spatial variability in the distribution of sediments linked to debris flows or turbidity currents, and in vertical stratal trends. Changes in allogenic (e.g., changes in base-level or, rate of sediment influx) and autogenic mechanisms (e.g., channel avulsion) are inferred as causes for significant differences in facies organization, both across distinct deltas and within individual deltaic edifices. The study highlights the marked variety of architectural and sedimentological (e.g., grain size, depositional processes) properties of Gilbert-type deltas. Findings allow the relation of outcrop observations to a general template and the quantitative determination of potential analogues with which to assist the prediction of the dimensions and facies of deltaic sedimentary bodies in the subsurface. Information on facies relationships and basinward variability of Gilbert-type deltas is valuable for the recognition and correlation of deltaic bodies in the subsurface