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Mechanical and hydraulic properties of carbonate rock:The critical role of porosity

Journal of Rock Mechanics and Geotechnical Engineering 2023年第4期15卷 814-825页

作者： Kam Ng J.carlos santamarina Department of Civil and Architectural Engineering and Construction Management University of WyomingLaramieWY82071USA Physical science and Engineering Division King Abdullah University of Science and TechnologyThuwal23955-6900Saudi Arabia

Carbonate rocks are extensively used in civil infrastructure and play a critical role in geoenergy geoengineering,either as hydrocarbon reservoirs or potential repositories for CO_(2)geological *** genesis and diagenetic overprint determine the properties of carbonate *** study combines recent data gathered from Madison Limestone and an extensive dataset compiled from published sources to analyze the hydraulic and mechanical properties of limestone carbonate *** models and data analyses recognize the inherently granular genesis of carbonate rocks and explain the strong dependency of physical properties on *** asymptotically-correct power model in terms of(1-Ф/Ф*)a is a good approximation to global trends of unconfined stiffness E and unconfined compressive strength UCs,cohesive intercept in Mohr-Coulomb failure envelopes,and the brittle-toductile transition *** power model is the analytical solution for the mechanical properties of percolating granular *** adopted a limiting granular porosityФ*=0.5 for all models,which was consistent with the loosest packing of monosize *** fitted power model has exponent(α=2)in agreement with percolation theory and highlights the sensitivity of mechanical properties to *** and models confirm a porosity-independent ratio between unconfined stiffness and strength,and the ratio follows a log-normal distribution with mean(E/UCs)≈*** high angle of internal shear strength measured for carbonate rocks reflects delayed contact failure with increased confinement,and it is not sensitive to *** spans more than six orders of *** size controls pore size and determines the reference permeability k^(*)at the limiting porosityФ*=*** a given grain size from fine to coarse-grained dominant carbonates,permeability is very sensitive to changes in porosity,suggesting preferential changes in the internal pore network during compaction.

关键词： Rock porosity Carbonate permeability Rock unconfined stiffness Unconfined compressive strength(UCs)

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A LoRa-based protocol for connecting IoT edge computing nodes to provide small-data-based services

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Digital Communications and Networks 2022年第3期8卷 257-266页

作者： Kiyoshy Nakamura Pietro Manzoni Alessandro Redondi Edoardo Longo Marco Zennaro Juan-carlos Cano carlos T.Calafate Universitat Politécnica de Valéncia ValenciaSpain Abdus salam International Centre for Theoretical Physics(ICTP) TriesteItaly Politecnico di Milano MilanItaly

Data is becoming increasingly *** regularly interact with a variety of structured data,ranging from sQLite databases on the phone to personal sensors and open government ***“digital traces left by individuals through these interactions”are sometimes referred to as“small data”.Examples of“small data”include driving records,biometric measurements,search histories,weather forecasts and usage *** this paper,we present a flexible protocol called LoRaCTP,which is based on LoRa technology that allows data“chunks”to be transferred over large distances with very low energy *** provides all the mechanisms necessary to make LoRa transfer reliable by introducing a lightweight connection setup and allowing the ideal sending of an as-long-as necessary data *** designed this protocol as communication support for small-data edge-based IoT solutions,given its stability,low power usage,and the possibility to cover long *** evaluated our protocol using various data content sizes and communication distances to demonstrate its performance and reliability.

关键词： small data Edge computing LoRa IoT

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Zeckendorf representations with at most two terms to x-coordinates of Pell equations

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science China Mathematics 2020年第4期63卷 627-642页

作者： carlos A.Gómez Florian Luca Departamento de Matematicas Universidad del ValleCali 25360Colombia school of Mathematics University of the WitwatersrandWits 2050South Africa Max Planck Institute for Mathematics Bonn 53111Germany Department of Mathematics Faculty of SciencesUniversity of OstravaOstrava 70103Czech Republic

In this paper,we find all positive squarefree integers d satisfying that the Pell equation X^2-d Y^2=±1 has at least two positive integer solutions(X,Y)and(X′,Y′)such that both X and X′have Zeckendorf representati... 详细信息

关键词： Pell equation Fibonacci numbers lower bounds for linear forms in logarithms reduction method

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Linking sedimentary provenance,climate and tectonics in the Neoproterozoic seridóBelt,Borborema Province(NE Brazil)

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Geoscience Frontiers 2023年第6期14卷 414-431页

作者： carlos V.A.Ribeiro Marcos C.C.sales Armando L.s.de Oliveira Ricardo sallet Programa de Pós-graduação em Geologia Instituto de GeociênciasUniversidade de Brasília(UnB)CEP 70910-900 BrasíliaDFBrazil Programa de Pós-Graduação em Geociências Universidade Federal de PernambucoDepartamento de GeologiaCentro de Tecnologia e GeociênciasAv.da ArquiteturaCEP 50740-530 RecifePEBrazil Departamento de Geologia Universidade Federal do Rio Grande do NorteCEP 59078-970 NatalRNBrazil

The seridóBelt,at the extreme northeast of Brazil,is one of the several Neoproterozoic mobile belts related to the Brasiliano/Pan-African Orogeny in Western *** lithostratigraphy of the seridóBelt comprises basal quartzites and metaconglomerates(Equador Formation)overlain by hornblende-bearing paragneisses,calc-silicate rocks and marbles(Jucurutu Formation)and biotiteschists(seridóFormation).We investigated the sedimentary provenance of these rocks based on an integration of compiled whole-rock geochemistry,sm-Nd isotopes,U-Pb detrital zircon ages and a new set of whole-rock trace elements *** Formation quartzites have major and trace elements patterns that resemble cratonic sandstones,with a typical felsic provenance consistent with the isotopic composition of plutonic Archean to Paleoproterozoic basement *** proxies suggest that these rocks were deposited in fresh waters under anoxic conditions and moderate to intense weathering conditions(CIA=58–79).A shift in provenance led to an increase in intermediate-mafic sources during the deposition of the Jucurutu and seridó*** elements from rock types in these units are nearly identical,yet they differ on the contents of some high field-strength elements(e.g.,sc,V and Ni),which are higher in the seridóFormation than average *** proxies show similar depositional environments,with brackish to marine conditions for the Jucurutu and seridóformations under anoxic to euxinic *** conditions are consistently lower in the Jucurutu Formation(CIA=58–66)in comparison with the seridóFormation(CIA=60–88).Compiled U-Pb data suggest maximum depositional ages of 633±11 Ma and 633±6 Ma for Jucurutu and seridóformations,respectively,suggesting deposition following the ca.645–635 Ma Marinoan *** compared the geochemistry of the seridóFormation schists with currently exposed basement rocks and showed a strong affinity with Neoproterozoic arc-related

关键词： Whole-rock geochemistry Marinoan Glaciation U-Pb detrital zircon Brasiliano Orogeny

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NPV risk simulation of an open pit gold mine project under the O'Hara cost model by using Gas

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International Journal of Mining science and Technology 2017年第3期27卷 557-565页

作者： franco-sepulveda Giovanni Campuzano carlos Pineda Cindy Department of Materials and Minerals National University of Colombia Medellin 050036 Colombia

This paper analyzes an open pit gold mine project based on the O'Hara cost model. Hypothetical data is proposed based on different authors that have studied open pit gold projects, and variations are proposed according to the probability distributions associated to key variables affecting the NPV, like production level, ore grade, price of ore, and others, so as to see what if, in a gold open pit mine project of 3000 metric tons per day of ore. Two case scenarios were analyzed to simulate the NPV, one where there is low certainty data available, and the other where the information available is of high certainty. Results based on genetic algorithm metaheuristic simulations, which combine basically Montecarlo simulations provided by the Palisade Risk software, the O'Hara cost model, net smelter return and financial analysis tools offered by Excel are reported, in order to determine to which variables of the project is more sensitive the NPV.

关键词： Genetic algorithms(GAs) O’Hara cost model Montecarlo simulation Open pit gold mine NPV risk analysis

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Control of Plant Growth and Defense by Photoreceptors:From Mechanisms to Opportunities in Agriculture

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Molecular Plant 2021年第1期14卷 61-76页

作者： Ronald Pierik carlos L.Ballare Plant Ecophysiology Department of BiologyUtrecht UniversityPadualaan 8Utrecht 3584 CHthe Netherlands IFEVA Consejo Nacional de Investigaciones Cientificas y TecnicasUniversidad de Buenos AiresAve.San Martin 4453C1417DSEBuenos AiresArgentina IIBIO-INTECH Consejo Nacional de Investigaciones Cientificas y TecnicasUniversidad Nacional de San MartinB1650HMPBuenos AiresArgentina

Plants detect and respond to the proximity of competitors using light signals perceived by photoreceptor proteins.A low ratio of red to far-red radiation(R:FR ratio)is a key signal of competition that is sensed by the photoreceptor phytochrome B(phyB).Low R:FR ratios increase the synthesis of growth-related hormones,including auxin and gibberellins,promoting stem elongation and other shade-avoidance *** photoreceptors that help plants to optimize their developmental configuration and resource allocation patterns in the canopy include blue light photoreceptors,such as cryptochromes and phototropins,and UV receptors,such as *** photoreceptors act by directly or indirectly controlling the activity of two major regulatory nodes for growth and development:the COP1/sPA ubiquitin E3 ligase complex and the PIF transcription *** is also an important modulator of hormonal pathways that regulate plant defense against herbivores and pathogens,including the jasmonic acid signaling pathway,In this Perspective,we discuss recent advances on the studies of the mechanisms that link photoreceptors with growth and *** these mechanisms is important to provide a functional platform for breeding programs aimed at improving plant productivity,stress tolerance,and crop health in species of agronomic interest,and to manipulate the light environments in protected agriculture.

关键词： photoreceptor phytochrome jasmonate growth-defense trade-off shade avoidance immunity

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CagA EPIYA polymorphisms in Colombian Helicobacter pylori strains and their influence on disease-associated cellular responses

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World Journal of Gastrointestinal Oncology 2013年第3期5卷 50-59页

作者： carlos Alberto Fajardo Andrés Javier Quiroga Andrea Coronado Karen Labrador Nicole Acosta Pilar Delgado carlos Jaramillo María Mercedes Bravo Cancer and Infectious Agents Research Group National Cancer Institute Molecular Diagnostics and Bioinformatics Laboratory Biological Sciences Department Los Andes University

AIM: To investigate the influence of the CagA diversity in Helicobacter pylori (H. pylori ) strains from Colombia on the host cell biology. METHODs: Eighty-four H. pylori-cagA positive strains with different Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs patterns, isolated from patients with gastritis (n=17), atrophic gastritis (n=17), duodenal ulcer (n=16), intestinal metaplasia (n=16) and gastric cancer (n=18), were included. To determine the integrity of the cag pathogenicity island (cag PAI) we evaluated the presence of cagA, cagT, cagE, and cag10 genes by polymerase chain reaction. AGs gastric epithelial cellswere infected with each strain and assayed for translo-cation and tyrosine phosphorylation of CagA by western blot, secretion of interleukin-8 (IL-8) by enzyme-linked immuno sorbent assay after taking supernatants from cocultures and cell elongation induction. For cell elongation quantification, coculture photographs were taken and the proportion of "hummingbird" cells (>15 μm) was determined. REsULTs: Overall 72% (60/84) of the strains were found to harbor a functional cag PAI. Levels of phos-phorylated CagA were significantly higher for isolates from duodenal ulcer than the ones in strains from gas-tritis, atrophic gastritis, intestinal metaplasia and gastric cancer (49.1% ± 23.1% vs 21.1% ± 19.5%, P s 26.2%±14.8%, Ps 21.5% ± 19.5%, Ps 29.5% ± 27.1%, P spectively). We observed variable IL-8 expression levels ranging from 0 to 810 pg/mL and from 8.8 to 1442 pg/mL at 6 h and 30 h post-infection, respectively. cagPAI-defective strains did not induce detectable levels of IL-8 at 6 h post-infection. At 30 h post-infection all strains induced IL-8 expression in AGs cells, although cagPAI-defective strains induced significantly lower levels of IL-8 than strains with a functional cagPAI (57.1 ± 56.6 pg/mL vs 513.6 ± 338.6 pg/mL,P serve differences in the extent of cell

关键词： Helicobacter pylori cagA 3’region CagA protein Interleukin 8 Cell elongation Glu-Pro-Ile-Tyr-Ala

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The Full Multi-wake Vortex Lattice Method:a detached flow model based on Potential Flow Theory

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Advances in Aerodynamics 2023年第1期5卷 452-477页

作者： Jesus carlos Pimentel-Garcia The school of Industrial Aerospace and Audiovisual Engineering of Terrassa(ESEIAAT)Polytechnic University of CataloniaTerrassa 08222Spain

One of the main issues concerning the standard Vortex Lattice Method is its application to partially or fully detached flow conditions,where non-linear aerodynamic characteristics appear as the angle of attack increases and/or the aspect ratio *** order to solve such limitations,a pure numerical approach based entirely on the Vortex Lattice Method concepts has been *** so-called steady“Full Multi-wake Vortex Lattice Method”comes from the main hypothesis that each discretized element on the body’s surface detaches their own wakes *** obtained results match for lift,drag and moment coefficients for the entire aspect ratio range configurations(under straight wakes and inviscid assumptions).Future unsteady versions of such a multi-wake approach could improve the current results obtained through Vortex Element Methods(as vortons or isolated vortex filaments).

关键词： Potential Flow Theory Ideal flow Detached flow Vorticity generation Vortex Lattice Method Kutta condition

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Immunological mechanisms of fecal microbiota transplantation in recurrent Clostridioides difficile infection

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World Journal of Gastroenterology 2022年第33期28卷 4762-4772页

作者： Lucas F soveral Gabriela G Korczaguin Pedro s schmidt Isabel s Nunes Camilo Fernandes carlos R Zarate-Blades Laboratory of Immunoregulation Department of MicrobiologyImmunologyand ParasitologyCenter for Dysbiosis ControlFederal University of Santa CatarinaFlorianopolis 88037-000Brazil Division of Infectious Diseases Hospital Nereu RamosFlorianopolis 88025-301Brazil

Fecal microbiota transplantation(FMT)is a successful method for treating recurrent Clostridioides difficile(***)infection(rCDI)with around 90%*** to the relative simplicity of this approach,it is being widely used and currently,thousands of patients have been treated with FMT ***,the mechanisms underlying its effects are just beginning to be *** indicate that FMT effectiveness is due to a combination of microbiological direct mechanisms against ***,but also through indirect mechanisms including the production of microbiota-derived metabolites as secondary bile acids and short chain fatty ***,the modulation of the strong inflammatory response triggered by *** after FMT seems to rely on a pivotal role of regulatory T cells,which would be responsible for the reduction of several cells and soluble inflammatory mediators,ensuing normalization of the intestinal mucosal immune *** this minireview,we analyze recent advances in these immunological aspects associated with the efficacy of FMT.

关键词： Fecal microbiota transplantation Immunity Mechanism Dysbiosis Pseudomembranous colitis Clostridioides difficile

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Eosinophilic esophagitis: Current concepts in diagnosis and treatment

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World Journal of Gastroenterology 2019年第32期25卷 4598-4613页

作者： Andrés Gómez-Aldana Mario Jaramillo-santos Andrés Delgado carlos Jaramillo Adán Lúquez-Mindiola Departament of Internal Medicine Section of GastroenterologySanta Fe Foundation of Bogotá(Fundación Santa Fe de Bogotá)Bogotá220246Colombia University of Los Andes Bogotá111711Colombia Department of Endoscopy Caldas UniversityManizales 275Colombia Department of Endoscopy Surgeons’Union SAS(Joint stock company)(Union de cirujanos SAS)Manizales 170001661Colombia Department of Gastroenterology Gut MédicaBogotá110221001Colombia

Eosinophilic esophagitis is an immune-allergic pathology of multifactorial etiology(genetic and environmental)that affects both pediatric and adult *** symptoms,which include heartburn,regurgitation,and esophageal stenosis(with dysphagia being more frequent in eosinophilic esophagitis in young adults and children),are similar to those of gastroesophageal reflux disease,causing delays in diagnosis and *** endoscopic findings such as furrows,esophageal mucosa trachealization,and whitish exudates may suggest its presence,this diagnosis should be confirmed histologically based on the presence of more than 15 eosinophils per high-power field and the exclusion of other causes of eosinophilia(parasitic infections,hypereosinophilic syndrome,inflammatory bowel disease,among others)for which treatment could be ***,the 3“D”s(“Drugs,Diet,and Dilation”)are considered the fundamental components of *** first 2 components,which involve the use of proton pump inhibitors,corticosteroids,immunosuppressants and empirical diets or guided food elimination based on allergy tests,are more useful in the initial phases,whereas endoscopic dilation is reserved for esophageal ***,the most important aspects of eosinophilic esophagitis pathophysiology will be reviewed,in addition to evidence for the various treatments.

关键词： Eosinophilic esophagitis Corticoid Esophageal stenosis Diet Dilation Proton pump inhibitor

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