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Examining the effect of adverse geological conditions on jamming of a single shielded TBM in Uluabat tunnel using numerical modeling

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journal of Rock Mechanics and Geotechnical Engineering 2017年第6期9卷 1112-1122页

作者： Rohola Hasanpour jürgen schmitt Yilmaz Ozcelik jamal Rostami Institute for Tunneling and Construction Management Ruhr-University Bochum Department of Civil Engineering Darmstadt University of Applied Science Department of Mining Engineering Hacettepe University Department of Mining Engineering Colorado School of Mines

Severe shield jamming events have been reported during excavation of Uluabat tunnel through adverse geological conditions, which resulted in several stoppages at advancing a single shielded tunnel boring machine(TBM). To study the jamming mechanism, three-dimensional(3D) simulation of the machine and surrounding ground was implemented using the finite difference code FLAC3D. Numerical analyses were performed for three sections along the tunnel with a higher risk for entrapment due to the combination of overburden and geological conditions. The computational results including longitudinal displacement contours and ground pressure profiles around the shield allow a better understanding of ground behavior within the excavation. Furthermore, they allow realistically assessing the impact of adverse geological conditions on shield jamming. The calculated thrust forces, which are required to move the machine forward, are in good agreement with field observations and measurements. It also proves that the numerical analysis can effectively be used for evaluating the effect of adverse geological environment on TBM entrapments and can be applied to prediction of loads on the shield and preestimating of the required thrust force during excavation through adverse ground conditions.

关键词： Single shielded tunnel boring machine(TBM) Numerical modeling Shield jamming Squeezing ground Uluabat tunnel

A force-compensated compliant MEMS-amplifier with electrostatic anti-springs

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Microsystems & Nanoengineering 2023年第3期9卷 235-244页

作者： Philip schmitt Martin Hoffmann Microsystems Technology Ruhr-Universität BochumUniversitätsstr.15044801 BochumGermany

In this paper,an electrostatic compliant mechanical amplifier intended for force-compensated displacement amplification in MEMS sensor applications is ***,mechanical transformers that enhance a small input displacement into a large output displacement generate large forces at the input of the *** microsystem proposed here allows for the reduction and compensation of the input stiffness of the amplifier and any mechanical components connected to it while providing a constant amplification ratio at the same *** amplifying mechanism features bidirectional electrostatic anti-springs enabling the control of the stiffness by applying a constant DC *** electrode design of the anti-springs and its influence on the force-displacement characteristic,the side instability and the maximal displacement are studied through analytical approaches and supported by FEA and by *** on the derived models,a compliant electromechanical amplifier is developed,featuring an amplification ratio of *** this amplifier the initial input stiffness of 422 N/m could be reduced to 6.8 N/m by applying a voltage of 100 *** an additional application,we show how the amplifier can be used as a mechanical force sensor with tuneable sensitivity,where the forces at the input are transformed into large output *** experiments,we show how the sensitivity can be adjusted and increased by a factor of 25 by applying a voltage at the anti-springs.

关键词： amplifier electrostatic spring

Prediction of TBM jamming risk in squeezing grounds using Bayesian and artificial neural networks

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journal of Rock Mechanics and Geotechnical Engineering 2020年第1期12卷 21-31页

作者： Rohola Hasanpour jamal Rostami jürgen schmitt Yilmaz Ozcelik Babak Sohrabian Institute for Tunneling and Construction Management Ruhr-University BochumBochumGermany Department of Mining Engineering Colorado School of MinesGoldenUSA Department of Civil Engineering Darmstadt University of Applied ScienceDarmstadtGermany Department of Mining Engineering Hacettepe UniversityAnkaraTurkey Faculty of Mining and Metallurgical Engineering Urmia University of TechnologyUrmiaIran

This study presents an application of artificial neural network(ANN)and Bayesian network(BN)for evaluation of jamming risk of the shielded tunnel boring machines(TBMs)in adverse ground conditions such as squeezing *** analysis is based on database of tunneling cases by numerical modeling to evaluate the ground convergence and possibility of machine *** results of initial numerical analysis were verified in comparison with some case studies.A dataset was established by performing additional numerical modeling of various scenarios based on variation of the most critical parameters affecting shield *** includes compressive strength and deformation modulus of rock mass,tunnel radius,shield length,shield thickness,in situ stresses,depth of over-excavation,and skin friction between shield and *** the dataset,an ANN was trained to predict the contact pressures from a series of ground properties and machine ***,the continuous and discretized BNs were used to analyze the risk of shield *** results of these two different BN methods are compared to the field observations and summarized in this *** developed risk models can estimate the required thrust force in both *** BN models can also be used in the cases with incomplete geological and geomechanical properties.

关键词： Bayesian network(BN) Artificial neural network(ANN) Shielded tunnel boring machine(TBM) jamming risk Numerical simulation Squeezing ground

Spatial modeling issues in future smart cities

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Geo-Spatial Information Science 2013年第1期16卷 7-12页

作者： Gerhard schmitt Department of Architecture and Future Cities Laboratory ETH ZürichZürichSwitzerlandand ETH CREATESingapore

It is our goal to make today’s and future cities smart,sustainable and *** order to achieve this,it is fundamental to understand how each city works,to formalize the knowledge gained and to apply it to a city model as the base for simulations that can generate future scenarios with a high level of *** nature of this model,which must cover design,qualitative and quantitative aspects,has changed over *** this study,we focus on the role of the spatial dimension and of geometry in a city *** from being a dominating generative force in ancient cities,spatial modeling has developed into an underlying description language for present and future cities to define functions and properties of the city in space and *** example of the stocks and flows model applied to the city depicts where and how spatial modeling influences the design,construction and performance of the future Smart City.

关键词： future cities spatial modeling stocks and flows city models reality-based 3D models

Apples to oranges:environmentally derived,dynamic regulation of serotonin neuron subpopulations in adulthood?

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Neural Regeneration Research 2025年第9期20卷 2596-2597页

作者： Christopher j.O’Connell Matthew j.Robson Department of Genetics College of MedicineHarvard UniversityBostonMAUSA james L.Winkle College of Pharmacy Division of Pharmaceutical SciencesUniversity of CincinnatiCincinnatiOHUSA Neuroscience Graduate Program College of MedicineUniversity of CincinnatiCincinnatiOHUSA

Traumatic brain injury(TBI)is a public health problem with an undue economic burden that impacts nearly every age,ethnic,and gender group across the globe(Capizzi et al.,2020).TBIs are often sustained during a dynamic range of exposures to energetic environmental forces and as such outcomes are typically heterogeneous regarding severity and pathology(Capizzi et al.,2020).

关键词： sustained orange dynamic

Temporal dynamics of neonatal hypoxic-ischemic encephalopathy injuries on magnetic resonance imaging

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Neural Regeneration Research 2025年第11期20卷 3144-3150页

作者： Holly Flyger Samantha j.Holdsworth Alistair j.Gunn Laura Bennet Hamid Abbasi Mātai Medical Research Institute Tairāwhiti GisborneNew Zealand Department of Anatomy&Medical Imaging Faculty of Medical and Health SciencesThe University of AucklandAucklandNew Zealand Center for Brain Research The University of AucklandAucklandNew Zealand Auckland Bioengineering Institute The University of AucklandAucklandNew Zealand

Moderate to severe perinatal hypoxic-ischemic encephalopathy occurs in~1 to 3/1000 live births in high-income countries and is associated with a significant risk of death or neurodevelopmental *** assessment is important to help identify highrisk infants,to help families,and to support appropriate interventions.A wide range of monitoring tools is available to assess changes over time,including urine and blood biomarkers,neurological examination,and *** present,magnetic resonance imaging is unique as although it is expensive and not suited to monitoring the early evolution of hypoxic-ischemic encephalopathy by a week of life it can provide direct insight into the anatomical changes in the brain after hypoxic-ischemic encephalopathy and so offers strong prognostic information on the long-term outcome after hypoxic-ischemic *** review investigated the temporal dynamics of neonatal hypoxic-ischemic encephalopathy injuries,with a particular emphasis on exploring the correlation between the prognostic implications of magnetic resonance imaging scans in the first week of life and their relationship to long-term outcome prediction,particularly for infants treated with therapeutic hypothermia.A comprehensive literature search,from 2016 to 2024,identified 20 pertinent *** review highlights that while the optimal timing of magnetic resonance imaging scans is not clear,overall,it suggests that magnetic resonance imaging within the first week of life provides strong prognostic *** challenges limit the timing consistency,particularly the need for intensive care and clinical ***,although most reports examined the prognostic value of scans taken between 4 and 10 days after birth,there is evidence from small numbers of cases that,at times,brain injury may continue to evolve for weeks after *** suggests that in the future it will be important to explore a wider range of times after hypo

关键词： magnetic resonance imaging neonatal hypoxic-ischemic encephalopathy neurodevelopmental outcomes prognostic biomarkers in neuroimaging scan timing therapeutic hypothermia

In memoriamWalter joseph Bock—a life dedicated to teaching and research in the biological sciences(20 November 1933-27 january 2022)

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Integrative Zoology 2022年第6期17卷 1215-1218页

作者： Michael schmitt john BUCKERIDGE Universität Greifswald Allgemeine&Systematische ZoologieGreifswaldGermany Professor Emeritus RMIT UniversityMelbourneVictoriaAustralia

Walter joseph Bock(Fig.1)was born in Woodhaven,Queens County,New York,NY(USA),the second of 4 children of Paul and Anne Bock,née *** grew up in a German speaking family who discontinued speaking German only at the outset of *** 1947 to 1951 he attended Brooklyn Technical High School,where there was considerable emphasis on technological *** 1951,he entered Cornell University in Ithaca,NY,graduating with a Bachelor of Science in *** Cornell,he attended a short lecture series presented by the famed ethologist Konrad Lorenz,and began an association with the ornithologist Charles *** links provided Walter with a growing appreciation of the wonders of the world of biology.

关键词： teaching Walter continued

Gene therapy for spinal muscular atrophy:perspectives on the possibility of optimizing SMN1 delivery to correct all neurological and systemic perturbations

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Neural Regeneration Research 2025年第7期20卷 2011-2012页

作者： Sharon j.Brown Rafael j.Yáñez-Muñoz Heidi R.Fuller School of Pharmacy and Bioengineering Keele UniversityKeeleUK Wolfson Center for Inherited Neuromuscular Disease TORCH BuildingRJAH Orthopaedic HospitalOswestryUK *** Center of Gene and Cell TherapyDepartment of Biological SciencesSchool of Life Sciences and the EnvironmentRoyal Holloway University of LondonEghamUK

Spinal muscular atrophy(SMA)is a genetic condition that results in selective lower motor neuron loss with concomitant muscle weakness and *** genetic cause of SMA was understood in 1995 when loss or impairment of the survival motor neuron 1(SMN1)gene was identified as the main contributing factor(Lefebvre et al.,1995).This,in combination with the discovery that humans have a“back-up”gene,SMN2,which can produce low levels(approximately 10%)of the full-length functional SMN protein,has led to the generation of SMA-specific gene *** was traditionally classified according to age of symptom onset and developmental milestones achieved,with life expectancy and severity varying between ***,SMN2 copy number is used as a proxy for the prediction of disease severity,with higher SMN2 copy number typically being associated with reduced severity of SMA,although this relationship is not absolute:some individuals with low SMN2 copy number have less severe SMA phenotypes and vice ***,the etiology of SMA is further complicated by other factors,such as non-typical nucleotide variants and SMN2-independent modifiers of disease severity.

关键词： atrophy traditionally absolute

Mitophagy:From the dark into the spotlight

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Molecular Plant 2023年第10期16卷 1487-1489页

作者： Vivian schmitt Olivier Van Aken Department of Biology Lund UniversityLundSweden

Despite the generally placid appearance of plants,many dynamicprocesses take place inside a plant *** such process thathas garnered attention in recent years is termed"autophagy."While originally discovered in yeast,our understanding of autophagy in plants has improved *** is considered a cellular recycling system in which cellular components oreven entire organelles can be encapsulated by a membranestructure(autophagosome)and then transported to the vacuole(in plants)for degradation and re-use.

关键词： attention organelle spite