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Effect of variations in rainfall intensity on slope stability in Singapore

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International Soil and Water Conservation Research 2017年第4期5卷 258-264页

作者： christofer kristo Harianto Rahardjo Alfrendo Satyanaga School of Civil and Environmental Engineering Nanyang Technological UniversityHall of Residence 9Block 46#04-867Singapore 639811Singapore School of Civil and Environmental Engineering Nanyang Technological UniversityBlk N150 Nanyang AvenueSingapore 639798Singapore

Numerous scientific evidence has given credence to the true existence and deleterious impacts of climate *** aspect of climate change is the variations in rainfall patterns,which affect the flux boundary condition across ground surface.A possible disastrous consequence of this change is the occurrence of rainfall-induced slope *** paper aims to investigate the variations in rainfall patterns in Singapore and its effect on slope ***'s historical rainfall data from Seletar and Paya Lebar weather stations for the period of 1985–2009 were obtained and analysed by duration using linear regression.A general increasing trend was observed in both weather stations,with a possible shift to longer duration rainfall events,despite being statistically insignificant according to the Mann-Kendall *** the derived trends,projected rainfall intensities in 2050 and 2100 were used in the seepage and slope stability analyses performed on a typical residual soil slope in Singapore.A significant reduction in factor of safety was observed in the next 50 years,with only a marginal decrease in factor of safety in the subsequent 50 *** indicates a possible detrimental effect of variations in rainfall patterns on slope stability in Singapore,especially in the next 50 *** statistical analyses on rainfall data from Seletar and Paya Lebar weather stations for the period of 1985–2009 indicated that rainfall intensity tend to increase over the years,with a possible shift to longer duration rainfall events in the *** stability analyses showed a significant decrease in factor of safety from 2003 to 2050 due to increase in rainfall intensity,suggesting that a climate change might have existed beyond 2009 with possibly detrimental effects to slope stability.

关键词： Climate change Rainfall Seepage Slope stability

A customizable,low-power,wireless,embedded sensing platform for resistive nanoscale sensors

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Microsystems & Nanoengineering 2022年第1期8卷 111-121页

作者： Stefan Nedelcu Kishan Thodkar christofer Hierold Micro-and Nanosystems Department of Mechanical and Process EngineeringETH ZurichTannenstrasse 38092 ZurichSwitzerland

Customizable,portable,battery-operated,wireless platforms for interfacing high-sensitivity nanoscale sensors are a means to improve spatiotemporal measurement coverage of physical *** a platform can enable the expansion of IoT for environmental and lifestyle *** we report a platform capable of acquiring currents ranging from 1.5 nA to 7.2μA full-scale with 20-bit resolution and variable sampling rates of up to 3.125 *** addition,it features a bipolar voltage programmable in the range of-10 V to+5 V with a 3.65 mV resolution.A Finite State Machine steers the system by executing a set of embedded *** FSM allows for dynamic,customized adjustments of the nanosensor bias,including elevated bias schemes for self-heating,measurement range,bandwidth,sampling rate,and measurement time ***,it enables data logging on external memory(SD card)and data transmission over a Bluetooth low energy *** average power consumption of the platform is 64.5 mW for a measurement protocol of three samples per second,including a BLE advertisement of a 0 dBm transmission power.A state-of-the-art(SoA)application of the platform performance using a CNT nanosensor,exposed to NO_(2) gas concentrations from 200 ppb down to 1 ppb,has been *** sensor signals are measured for NO_(2) concentrations of 1 ppb,the 3σlimit of detection(LOD)of 23 ppb is determined(1σ:7 ppb)in slope detection mode,including the sensor signal variations in repeated *** platform’s wide current range and high versatility make it suitable for signal acquisition from resistive nanosensors such as silicon nanowires,carbon nanotubes,graphene,and other 2D *** with its overall low power consumption,the proposed platform is highly suitable for various sensing applications within the context of IoT.

关键词： power IoT enable

Aberrant DNA repair as a potential contributor for the clonal evolution in subsets of anaplastic thyroid carcinomas arising through dedifferentiation: implications for future therapeutic algorithms?

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Cancer Drug Resistance 2020年第4期3卷 992-1000页

作者： Carl christofer Juhlin Department of Oncology-Pathology Karolinska InstitutetStockholm SE-17176Sweden Department of Pathology and Cytology Karolinska University HospitalStockholm SE-17176Sweden

Well-differentiated thyroid carcinoma(WDTC,including papillary thyroid carcinoma and follicular thyroid carcinoma)are fairly slow-growing tumors with an overall low mortality due to the efficacy of combinatory surgery and postoperative radioiodine *** of WDTCs may dedifferentiate into poorly differentiated thyroid carcinoma(PDTC)and anaplastic thyroid carcinoma(ATC),of which especially the latter has an exceptionally poor patient *** underlying genetics responsible for this tumor progression is only partly understood,and is complicated by the fact that subgroups of ATCs are thought to arise de novo without a demonstrable,pre-existing *** so,recent advances using next generation sequencing(NGS)techniques have identified a genetic link between WDTCs and ATCs,suggesting a step-wise accumulation of mutations driving the loss of differentiation for most *** this Commentary,recent findings from an NGS study on synchronous FTC,PDTC,and ATC tumor components from the same patient are *** using whole-genome data,clonality analyses identified a chief ancestral clone carrying mutations in TP53-associated signaling networks regulating genes involved in DNA repair,with sub-clones in each tumor component that were identified also in the less differentiated,neighboring ***,mutational signatures suggested a general mismatch repair(MMR)deficiency along with microsatellite *** findings support the chained progression model of dedifferentiation in thyroid cancer,and pinpoint a central role for defective DNA *** effective treatment modalities for ATCs are urgently needed,studies regarding therapeutic agents specifically targeting defective MMR in dedifferentiated thyroid carcinoma could be pursued.

关键词： DNA repair mismatch repair P53 thyroid carcinoma dedifferentiation anaplastic thyroid carcinoma clone treatment

Urbanization affects plant flowering phenology and pollinator community:effects of water availability and land cover

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Ecological Processes 2014年第1期3卷 83-94页

作者： Kaesha Neil Jianguo Wu christofer Bang Stanley Faeth School of Life Sciences Arizona State UniversityP.O.Box 874501TempeAZ 85287-4501USA School of Sustainability Global Institute of SustainabilityArizona State UniversityTempeAZ 85287USA Department of Biology University of North Carolina-GreensboroGreensboroNC 27402USA.

Introduction:Climate change and urbanization have been shown to alter plant ***,a mechanistic understanding of these changes in flowering phenology and associated pollinator communities is ***,this study was designed to examine finer scale flowering phenological patterns and driving processes in an arid urban ***,we tested the effect of water availability and land cover type on the flowering phenology of brittlebush(Encelia farinosa)and investigated the arthropod pollinator community associated with ***:The fieldwork was carried out as part of a larger community ecology experiment following a factorial nested *** chose three land cover types,each of which had three replicates,resulting in a total of nine *** water availability manipulations,60 genetically different 5-gallon potted plants were placed on the ground within each ***-trapping was used to collect potential ***:Our results showed that water availability did not produce significant differences in flowering ***,brittlebush planted in mesiscaped urban sites bloomed later,longer,and at a higher percentage than those planted in desert remnant sites and desert fringe ***,desert remnant sites were significantly lower in pollinator abundance than desert fringe *** richness varied over time in all land cover ***:This study provides empirical evidence that land cover type,which is strongly correlated to temperature,is the primary cause for altered flowering phenology of brittlebush in the Phoenix area,although water availability may also be ***,land cover affects total abundance of bee pollinators.

关键词： Urban ecology Urban heat island effects Flowering phenology Land cover Pollinators

An in vitro demonstration of a passive,acoustic metamaterial as a temperature sensor with mK resolution for implantable applications

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Microsystems & Nanoengineering 2024年第1期10卷 41-54页

作者： Lucrezia Maini Vicente Genovés Roman Furrer Nikola Cesarovic christofer Hierold Cosmin Roman Micro-and Nanosystems Department of Mechanical and Process EngineeringETH ZurichTannenstrasse 38092 ZurichSwitzerland. Translational Cardiovascular Technology Department of Health Science and TechnologyETH ZurichLeopold-Ruzicka-Weg 48093 ZurichSwitzerland. Transport at Nanoscale Interfaces Swiss Federal Laboratories for Materials Science and TechnologyEMPAÜberlandstrasse 1298600 DübendorfSwitzerland Department of Cardiothoracic and Vascular Surgery Deutsches Herzzentrum der Charite(DHZC)13353 BerlinGermany

Wireless medical sensors typically utilize electromagnetic coupling or ultrasound for energy transfer and sensor *** transfer and management is a complex aspect that often limits the applicability of implantable sensor *** this work,we report a new passive temperature sensing scheme based on an acoustic metamaterial made of silicon embedded in a polydimethylsiloxane *** to other approaches,this concept is implemented without additional electrical components in situ or the need for a customized receiving unit.A standard ultrasonic transducer is used for this demonstration to directly excite and collect the reflected *** metamaterial resonates at a frequency close to a typical medical value(5 MHz)and exhibits a high-quality *** the design features of the metamaterial with the high-temperature sensitivity of the polydimethylsiloxane matrix,we achieve a temperature resolution of 30 *** value is below the current standard resolution required in infrared thermometry for monitoring postoperative complications(0.1 K).We fabricated,simulated,in vitro tested,and compared three acoustic sensor designs in the 29-43℃(~302-316 K)temperature *** this concept,we demonstrate how our passive metamaterial sensor can open the way toward new zero-power smart medical implant concepts based on acoustic interrogation.

关键词： passive resolution utilize

Enabling direct microcalorimetric measurement of metabolic activity and exothermic reactions onto microfluidic platforms via heat flux sensor integration

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Microsystems & Nanoengineering 2023年第3期9卷 103-114页

作者： Signe L.K.Vehusheia Cosmin Roman Olivier Braissant Markus Arnoldini christofer Hierold Micro and Nanosystems Department of Mechanical and Process EngineeringETH ZurichTannenstrasse 38092 ZurichSwitzerland Center of Biomechanics and Biocalorimetry Department of Biomedical EngineeringUniversity of BaselHegenheimermattweg 167C4123 AllschwilSwitzerland Laboratory for Food Immunology Department of Health Sciences and TechnologyETH ZurichOtto-Stern-Weg 38093 ZurichSwitzerland

All biological processes use or produce *** microcalorimeters have been utilized to study the metabolic heat output of living organisms and heat production of exothermic chemical *** advances in microfabrication have made possible the miniaturization of commercial microcalorimeters,resulting in a few studies on the metabolic activity of cells at the microscale in microfluidic *** we present a new,versatile,and robust microcalorimetric differential design based on the integration of heat flux sensors on top of microfluidic *** show the design,modeling,calibration,and experimental verification of this system by utilizing Escherichia coli growth and the exothermic base catalyzed hydrolysis of methyl paraben as use *** system consists of a Polydimethylsiloxane based flow-through microfluidic chip with two 46µl chambers and two integrated heat flux *** differential compensation of thermal power measurements allows for the measurement of bacterial growth with a limit of detection of 1707 W/m^(3),corresponding to 0.021OD(2·10^(7) bacteria).We also extracted the thermal power of a single Escherichia coli of between 1.3 and 4.5 pW,comparable to values measured by industrial *** system opens the possibility for expanding already existing microfluidic systems,such as drug testing lab-on-chip platforms,with measurements of metabolic changes of cell populations in form of heat output,without modifying the analyte and minimal interference with the microfluidic channel itself.

关键词： system utilizing versatile

High-speed identification of suspended carbon nanotubes using Raman spectroscopy and deep learning

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Microsystems & Nanoengineering 2022年第1期8卷 259-267页

作者： Jian Zhang Mickael L.Perrin Luis Barba Jan Overbeck Seoho Jung Brock Grassy Aryan Agal Rico Muff Rolf Brönnimann Miroslav Haluska Cosmin Roman christofer Hierold Martin Jaggi Michel Calame Laboratory for Transport at Nanoscale Interfaces EmpaSwiss Federal Laboratories for Materials Science and TechnologyCH-8600 DübendorfSwitzerland Machine Learning and Optimization Laboratory School of Computer and Communication SciencesEPFLCH-1015 LausanneSwitzerland Department of Physics and Swiss Nanoscience Institute University of BaselCH-4056 BaselSwitzerland Micro-and Nanosystems Department of Mechanical and Process EngineeringETH ZurichCH-8092 ZurichSwitzerland

The identification of nanomaterials with the properties required for energy-efficient electronic systems is usually a tedious human task.A workflow to rapidly localize and characterize nanomaterials at the various stages of their integration into large-scale fabrication processes is essential for quality control and,ultimately,their industrial *** this work,we develop a high-throughput approach to rapidly identify suspended carbon nanotubes(CNTs)by using high-speed Raman imaging and deep learning *** for Raman spectra with extremely low signal-to-noise ratios(SNRs)of 0.9,we achieve a classification accuracy that exceeds 90%,while it reaches 98%for an SNR of *** applying a threshold on the output of the softmax layer of an optimized convolutional neural network(CNN),we further increase the accuracy of the ***,we propose an optimized Raman scanning strategy to minimize the acquisition time while simultaneously identifying the position,amount,and metallicity of CNTs on each *** approach can readily be extended to other types of nanomaterials and has the potential to be integrated into a production line to monitor the quality and properties of nanomaterials during fabrication.

关键词： carbon suspended speed

An Overview of Oligocene to Recent Sediments of the Western Pacific Warm Pool(WPWP)(International Ocean Discovery Program-IODP Exp.363)Using Warm and Cool Foraminiferal Species

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Journal of Marine Science 2021年第3期3卷 21-35页

作者： Patrícia Pinheiro Beck Eichler christofer Paul Barker Moab Praxedes Gomes Helenice Vital Programa de Pós-Graduação em Geodinâmica e Geofísica(PPGG) Universidade Federal do Rio Grande do Norte(UFRN)Campus UniversitárioLagoa Nova59072-970-NatalRNBrazil Ecologic Project Boulder CreekCaliforniaUnited States

We use the excellent sediment recovery of International Ocean Discovery Program(IODP)Exp.363,in the Western Pacific Warm Pool(WPWP)to assess down-core variations in the abundance of warm versus cool benthic foraminiferal species through a warm benthic foraminifers(WBF)*** total percentage of the“warm”shallower species group(Laticarinina pauperata,Cibicidoides kullenbergi,***,Cibicidoides sp.,Hoeglundina elegans,and Bulimina aculeata)and of the“cool”species group from deep waters(Pyrgo murrhina,Planulina wuellerstorfi,Uvigerina peregrina,and Globobulimina hoeglundi,Hopkinsina pacifica)at all sites is used to assess paleo temporal and spatial variations in preservation and marine *** study sites span water depths ranging from 875 m to 3421 m and our results indicate that well-preserved living and fossil foraminifera characterize mudline and core sediments at all water depths attesting the wide environmental tolerance of these species to temperature and *** magneto-and biostratigraphy datum,these sediments are of Oligocene *** low-resolution study showed that with the exception of core 1486B which the linear tendency of warmer species is toward cool sediments in old times,all of them show that older sediments indicate warmer periods than today,which is expected from Miocene to *** results provide evidence for the preservation potential of deeply buried sediments,which has implications on climate reconstructions based on the population dynamics of calcareous benthic foraminifera.

关键词： Miocene Population dynamics Climate change Tolerance Temporal Spatial

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5G网络规划设计与优化