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"Miles wide and miles deep"-Exploring the depth and breadth of geoscience during the first ten years of Geoscience Frontiers

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Geoscience Frontiers 2019年第3期10卷 1219-1221页

作者： christopher j. Spencer Nick M.W.Roberts Damian Nance The Institute of Geoscience Research (TIGeR) School of Earth and Planetary Sciences Curtin University NERC Isotope Geosciences Laboratory British Geological Survey Department of Geological Sciences Ohio University Department of Geology and Geophysics Yale University

When early explorers first crossed the Platte River in what is now Nebraska (USA), it was said the river was “a mile wide and an inch deep”(Mokler, 1923;Smith, 1971). This phrase was used to describe not only the difficulty in crossing the river but also in navigating its length. The trouble with a river being too wide is the risk that it won’t provide the depth necessary to be useful. The same thing can be said of multidisciplinary scientific journals. While a journal can claim to be multidisciplinary, there is a risk of it being so broad that its articles can only engage the reader at a superficial level. Nothing could be further from the truth with Geoscience Frontiers. Over the past ten years, this journal has successfully navigated the wide breadth of geoscience while providing a level of depth and detail that rivals discipline-specific journals.

关键词： engage its was can past be is now

Non-alcoholic fatty liver disease: a narrative review of genetics

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The journal of Biomedical Research 2018年第6期32卷 389-400页

作者： christopher j.Danford Zemin Yao Z.Gordon jiang Division of Gastroenterology and Hepatology Beth Israel Deaconess Medical Center Department of Biochemistry Microbiology and Immunology Ottawa Institute of Systems Biology University of Ottawa

Non-alcoholic fatty liver disease(NAFLD) is now the most common cause of chronic liver diseases worldwide. It encompasses a spectrum of disorders ranging from isolated hepatic steatosis to nonalcoholic steatohepatitis(NASH),fibrosis, cirrhosis, and hepatocellular carcinoma. One of the key challenges in NAFLD is identifying which patients will progress. Epidemiological and genetic studies indicate a strong pattern of heritability that may explain some of the variability in NAFLD phenotype and risk of progression. To date, at least three common genetic variants in the PNPLA3, TM6 SF2, and GCKR genes have been robustly linked to NAFLD in the population. The function of these genes revealed novel pathways implicated in both the development and progression of NAFLD. In addition,candidate genes previously implicated in NAFLD pathogenesis have also been identified as determinants or modulators of NAFLD phenotype including genes involved in hepatocellular lipid handling, insulin resistance,inflammation, and fibrogenesis. This article will review the current understanding of the genetics underpinning the development of hepatic steatosis and the progression of NASH. These newly acquired insights may transform our strategy to risk-stratify patients with NAFLD and to identify new potential therapeutic targets.

关键词： NAFLD NASH genetics PNPLA3 TM6SF2 GCKR MBOAT7

An experimental study of elastic properties of dragonfly-like flapping wings for use in biomimetic micro air vehicles(BMAVs)

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Chinese journal of Aeronautics 2017年第2期30卷 726-737页

作者： Praveena Nair Sivasankaran Thomas Arthur Ward Erfan Salami Rubentheren Viyapuri christopher j.Fearday Mohd Rafie johan Department of Mechanical Engineering University of Malaya KuaIa Lumpur 50603 Malaysia School of Engineering and Physical Sciences Heriot-Watt University Malaysia Putrajaya 62200 Malaysia Department of Electrical Engineering University of Malaya Kuala Lumpur 50603 Malaysia

This article studies the elastic properties of several biomimetic micro air vehicle（BMAV）wings that are based on a dragonfly *** are a new class of unmanned micro-sized air vehicles that mimic the flapping wing motion of flying biological organisms（e.g.,insects,birds,and bats）.Three structurally identical wings were fabricated using different materials：acrylonitrile butadiene styrene（ABS）,polylactic acid（PLA）,and *** wing frame structures were fabricated from these materials and then a nanocomposite film was adhered to them which mimics the membrane of an actual *** wings were then attached to an electromagnetic actuator and passively flapped at frequencies of 10-250 Hz.A three-dimensional high frame rate imaging system was used to capture the flapping motions of these wings at a resolution of 320 pixels x 240 pixels and 35000 frames per *** maximum bending angle,maximum wing tip deflection,maximum wing tip twist angle,and wing tip twist speed of each wing were measured and compared to each other and the actual dragonfly *** results show that the ABS wing has considerable flexibility in the chordwise direction,whereas the PLA and acrylic wings show better conformity to an actual dragonfly wing in the spanwise *** studies have shown that the aerodynamic performance of a BMAV flapping wing is enhanced if its chordwise flexibility is increased and its spanwise flexibility is ***,the ABS wing（fabricated using a 3D printer） shows the most promising results for future applications.

关键词： ABS Acrylic Biomimetic micro air vehicle Flapping mechanism PLA Wing structure

Development of a new algorithm for implementing the edge effect offset for subsidence calculations

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International journal of Mining Science and Technology 2018年第1期28卷 61-66页

作者： joshua Hescock christopher Newman Zach Agioutantis Department of Mining Engineering University of Kentucky

The surface deformation prediction system(SDPS) program has been developed as an engineering tool for the calculation of subsidence deformation indices through the implementation of various prediction *** basic user-defined input parameters, SDPS can determine subsidence indices, such as mining induced displacements, strains, tilt, etc., at any elevation between the seam and the horizontal or varying surface topography.A fundamental parameter in obtaining reliable ground deformation results is the determination of the edge effect *** value assigned to the edge effect offset corresponds to a virtual offsetting of boundary lines delineating the extracted panel to allow for roof cantilevering over the mined-out *** objective of this paper is to describe the methods implemented in updating the edge effect offset algorithm within *** proven geometric equations, the newly developed algorithm provides a more robust calculation of the offset boundary of the extracted panel for simplistic as well as more complex mining *** that an extracted panel is represented by a closed polyline, the new edge offset algorithm calculates a polyline offset into the extracted panel with respect to the user defined edge effect offset *** deformations are then calculated using this adjusted panel *** Matlab program was utilized for development and testing of the new edge effect offset *** completing rigorous testing regimes, the new offset algorithm will be integrated into SDPS further increasing the speed and reliability of the program resulting in a retrospective increase in capability and flexibility.

关键词： Subsidence Coal mining Influence function Edge effect

Influence of residual stresses on failure pressure of cylindrical pressure vessels

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Chinese journal of Aeronautics 2013年第6期26卷 1415-1421页

作者： M.jeyakumar T.christopher Department of Mechanical Engineering Sardar Raja College of EngineeringAlangulamTirunelveli 627 808India Department of Mechanical Engineering Government College of EngineeringTirunelveli 627 007India

The utilization of pressure vessels in aerospace applications is *** this work,fnite element analysis（FEA）has been carried out using ANSYS software package with 2D axisymmetric model to access the failure pressure of cylindrical pressure vessel made of ASTM A36 carbon steel having weld-induced residual *** fnd out the effect of residual stresses on failure pressure,frst an elasto-plastic analysis is performed to fnd out the failure pressure of pressure vessel not having residual *** a thermo-mechanical fnite element analysis is performed to assess the residual stresses developed in the pressure vessel during *** one more elasto-plastic analysis is performed to assess the effect of residual stresses on failure pressure of the pressure vessel having residual *** analysis indicates reduction in the failure pressure due to unfavorable residual stresses.

关键词： Aerospace engineering ASTM A36 Finite element analysis Pressure vessels Welding residual stress

Multi-mode diagnosis of a gas turbine engine using an adaptive neuro-fuzzy system

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Chinese journal of Aeronautics 2018年第1期31卷 1-9页

作者： Houman HANACHI jie LIU christopher MECHEFSKE National Research Base of Intelligent Manufacturing Service Chongqing Technology and Business University Chongqing 400067 China Department of Mechanical and Materials Engineering Queen's University Kingston ON K7L 3N6 Canada Department of Mechanical and Aerospace Engineering Carleton University Ottawa ON K1S 5B6 Canada

Gas Turbine Engines （GTEs） are vastly used for generation of mechanical power in a wide range of applications from airplane propulsion systems to stationary power plants. The gaspath components of a GTE are exposed to harsh operating and ambient conditions, leading to several degradation mechanisms. Because GTE components are mostly inaccessible for direct measure- ments and their degradation levels must be inferred from the measurements of accessible parameters, it is a challenge to acquire reliable information on the degradation conditions of the parts in different fault modes. In this work, a data-driven fault detection and degradation estima- tion scheme is developed for GTE diagnostics based on an Adaptive Neuro-Fuzzy Inference System （ANFIS）. To verify the performance and accuracy of the developed diagnostic framework on GTE data, an ensemble of measurable gas path parameters has been generated by a high-fidelity GTE model under （a） diverse ambient conditions and control settings, （b） every possible combination of degradation symptoms, and （c） a broad range of signal to noise ratios. The results prove the competency of the developed framework in fault diagnostics and reveal the sensitivity of diagnostic results to measurement noise for different degradation symptoms.

关键词： Fault detection Multi-mode diagnosis Measurement noise Real-time diagnosis

ABCD^(2) risk score does not predict the presence of cerebral microemboli in patients with hyper-acute symptomatic critical carotid artery stenosis

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Stroke & Vascular Neurology 2017年第2期2卷 41-46页

作者： Mahmud Saedon Charles E Hutchinson christopher H E Imray Donald R j Singer Warwick Medical School University of WarwickCoventryUK University Hospitals Coventry Warwickshire NHS Trust CoventryUK Fellowship of Postgraduate Medicine LondonUK Yale School of Medicine New HavenConnecticutUSA

Introduction:ABCD^(2) risk score and cerebral microemboli detected by transcranial Doppler(TCD)have been separately shown to the predict risk of recurrent acute *** studied whether ABCD2 risk score predicts cerebral microemboli in patients with hyper-acute symptomatic carotid artery *** and methods:We studied 206 patients presenting within 2 weeks of transient ischaemic attack or minor stroke and found to have critical carotid artery stenosis(≥50% ).86 patients(age 70±1(SEM:years),58 men,83 Caucasian)had evidence of microemboli;72(84% )of these underwent carotid endarterectomy(CEA).120 patients(age 72±1 years,91 men,113 Caucasian)did not have microemboli detected;102(85% )of these underwent *** were analysed using X2 and Mann–Whitney U tests and receiver operating characteristic(ROC)***:140/206(68% :95% CI 61.63 to 74.37)patients with hyper-acute symptomatic critical carotid stenosis had an ABCD2 risk score≥*** was no significant difference in the NICE red flag criterion for early assessment(ABCD^(2) risk score≥4)for patients with cerebral microemboli versus those without microemboli(59/86 vs 81/120 patients:OR 1.05 ABCD2 risk score≥4(95% CI 0.58 to 1.90,p=0.867)).The ABCD2 risk score wasjusting for pre-neurological event antiplatelet treatment(APT),area under the curve(AUC)of ROC for ABCD2 risk score showed no prediction of cerebral microemboli(no pre-event APT,n=57:AUC 0.45(95% CI 0.29 to 0.60,p=0.531);preevent APT,n=147:AUC 0.51(95% CI 0.42 to 0.60,p=0.804)).Conclusions:The ABCD2 score did not predict the presence of cerebral microemboli or carotid disease in over one-quarter of patients with symptomatic critical carotid artery *** the basis of NICE guidelines(refer early if ABCD2≥4),assessment of high stroke risk based on ABCD2 scoring may lead to inappropriate delay in urgent treat

关键词： patients cerebral emboli

Developing a USLE cover and management factor(C)for forested regions of southern China

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Frontiers of Earth Science 2020年第3期14卷 660-672页

作者： Conghui Li Lili Lin Zhenbang Hao christopher j.Post Zhanghao Chen jian Liu Kunyong Yu Fujian Agriculture and Forestry University Fuzhou350002China University Key Laboratory for Geomatics Technology and Optimized Resources Utilization in Fujian Province Fuzhou350002China Department of Forestry and Environmental Conservation Clemson UniversityClemsonSC29634USA

The Universal Soil Loss Equation model is often used to improve soil resource conservation by monitoring and forecasting soil *** study tested a novel method to determine the cover and management factor(C)of this model by coupling the leaf area index(LAI)and soil basal respiration(SBR)to more accurately estimate a soil erosion map for a typical region with red soil in Hetian,Fujian Province,*** spatial distribution of the LAI was obtained using the normalized difference vegetation index and was consistent with the LAI observed in the field(R^2=0.66).The spatial distribution of the SBR was obtained using the Carnegie-Ames-Stanford Approach model and verified by soil respiration field observations(R^2=0.51).Correlation analyses and regression models suggested that the LAI and SBR could reasonably reflect the structure of the forest canopy and understory vegetation,***,the C-factor was reconstructed using the proposed forest vegetation structure factor(Cs),which considers the effect of the forest canopy and shrub and litter layers on reducing rainfall *** feasibility of this new method was thoroughly verified using runoff plots(R2=0.55).The results demonstrated that Cs may help local governments understand the vital role of the structure of the vegetation layer in limiting soil erosion and provide a more accurate large-scale quantification of the C-factor for soil erosion.

关键词： leaf area index remote sensing soil basal respiration forest vegetation structure factor vegetation layer structure

Development of a multiple level underground limestone mine from geology through mine planning

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International journal of Mining Science and Technology 2020年第1期30卷 63-67页

作者： christopher Newman David Newman Robert Dupuy Appalachian Mining&Engineering Inc.LexingtonKYUSA Rogers Group Inc.NashvilleTNUSA

The development of a multiple level underground mine is a complex task in which geology,engineering,ground control,and unit operations are integrated into a single mine *** components are interdependent and must function cohesively to ensure a profitable underground mining *** optimize reserve recovery,mine planning should begin from the lowest level and progress *** limits any misjudgments or oversights of a given level affecting the underlying levels and ensures the ability to maximize recovery from each *** planning should start with the exploration and characterization of the geologic *** the reserve geology and quality is well understood,then mine planning can begin with respect to the following:(1)orientation of mine works with respect to horizontal stress;(2)access to the reserve;(3)determination of opening widths;(4)selection of back,floor horizons and pillar centers;(5)selection of development and secondary mining heights;(6)appropriate inter-burden thicknesses;and(7)examining the stability of the multiple level mine through numerical *** multiple level mine design process and decisions are presented through a case history *** theme is that there is one opportunity to"get it right"and many chances to overlook a small aspect within the design that will plague the mine throughout all levels and through the entirety of its operating life.

关键词： Limestone Mine planning Geology Multiple level Rock mechanics