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Estimating rock properties using sound signal dominant frequencies during diamond core drilling operations

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第4期11卷 850-859页

作者： ch.Vijaya Kumar Harsha Vardhan ch.S.n.Murthy n.C.Karmakar Department of Mining Engineering National Institute of Technology KarnatakaSurathkalIndia Indian Institute of Technology (BHU) VaranasiIndia

In many engineering applications such as mining,geotechnical and petroleum industries,drilling operation is widely *** drilling operation produces sound by-product,which could be helpful for preliminary estimation of the rock ***,determination of rock properties is very difficult by the conventional methods in terms of high accuracy,and thus it is expensive and *** this context,a new technique was developed based on the estimation of rock properties using dominant frequencies from sound pressure level generated during diamond core drilling ***,sound pressure level was recorded and sound signals of these sound frequencies were analyzed using fast Fourier transform (FFT).Rock drilling experiments were performed on five different types of rock samples using computer numerical control (CnC) drilling machine BMV 45 *** simple linear regression analysis,mathematical equations were developed for various rock properties,*** compressive strength,Brazilian tensile strength,density,and dominant frequencies of sound pressure *** developed models can be utilized at early stage of design to predict rock properties.

关键词： Rock properties Sound pressure level Fast Fourier transform (FFT) Sound signal Core drilling Dominant frequencies

Can a dam type of an alpine lake be derived from lake geometry?A negative result

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Journal of Mountain Science 2021年第3期18卷 614-621页

作者： Adam EMMER Vojtěch CURIn University of Graz Institute of Geography and Regional ScienceCascade|The Mountain Processes and Mountain Hazards GroupGraz 8010Austria Czech Academy of Sciences Prague 16500Czechia Global change Research Institute Czech University of Life Sciences PragueFaculty of Environmental SciencesBrno 60300Czechia

Glacial lake outburst floods(GLOFs)represent one of the most serious hazard and risk in deglaciating high mountain regions worldwide and the need for GLOF hazard and risk assessment is *** a consequence,numerous region-and nation-wide GLOF assessment studies have been published *** studies cover large areas and consider hundreds to thousands of lakes,prioritizing the hazard posed by ***,certain simplification is required for executing such studies,often resulting in neglecting qualitative characteristics which would need manual *** lake dam types(e.g.,bedrock-dammed,moraine-dammed)are often not distinguished,despite they control GLOF mechanism(dam overtopping/dam breach)and thus GLOF *** this study,we explore the potential of easily measurable quantitative characteristics and four ratios to approximate the lake dam *** dataset of 851 lakes of the Cordillera Blanca suggests that while variances and means of these characteristics of individual lake types differ significantly(F-test,t-test),value distribution of different geometrical properties can’t be used for the originally proposed purpose along the *** only promising results are obtained for extreme values(selected bins)of the *** instance,the low width to length ratio indicates likely morainedammed lake while the high value of ratio indicating round-shape of the lake indicates increased likelihood of bedrock-dammed ***,we report a negative result of our experiment since there are negligible differences of relative frequencies in most of the bins along the spectra.

关键词： Alpine lake High mountain lake GLOFs Glacial lake Moraine-dammed Bedrock-dammed negative result Cordillera Blanca

Evaluation of ligninolytic activity in spent mushroom substrate from four cultivated mushrooms

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Journal of Bioresources and Bioproducts 2022年第4期7卷 288-294页

作者： Ana Marión Pérez-chávez María Melisa Alberti Edgardo Albertó Laboratory of Mycology and Mushroom Cultivation.Instituto Tecnológico de chascomús(InTEch) Universidad Nacional de San Martín(UNSAM)-Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET)Intendente Marino AveCC 164.7130ChascomúsBuenos AiresArgentina

Spent mushroom substrate(SMS)is an abundant residue generated by the mushroom industry,which is mostly *** this study,the SMS of four cultivated mushrooms were evaluated as potential sources of ligninolytic *** ostreatus,***,*** and Ganoderma lucidum were cultivated in two different substrates to determine growth,mushroom yields and ligninolytic activity of laccase(Lac)and manganese peroxidase(MnP).Maximum activities in the SMS were 3.731 U/g Lac and 0.191 U/g MnP,both for *** mushroom substrates were also analyzed,and higher activities were found in almost all samples.A correlation test between mushroom yields and ligninolytic activities of each culture was made,and we found that high enzymatic activity in the substrate did not result in high mushroom productivity or vice *** SMS was a good source of ligninolytic *** activity depended on the mushroom species and its affinity to the substrate,and it was not influenced by the mushroom *** of mushrooms in diverse lignocellulosic substrates is gaining interest,and ob-taining ligninolytic enzymes from residual SMS is an excellent alternative in the circular economy concept.

关键词： Laccase Manganese peroxidase Biological efficiency Pleurotus spp Ganoderma lucidum Circular economy

Polygeneration Study of Low-to-Medium Enthalpy Geothermal Reservoirs in Mexico

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Journal of Thermal Science 2021年第3期30卷 1077-1087页

作者： chÁVEZ Oscar GODÍnEZ Francisco Tecnológico nacional de México/I.T.chihuahua.Av.Tecnológico 2909 C.P.31310ChihuahuaChihuahuaMéxico Instituto de Ingeniería Universidad Nacional Autónoma de MéxicoUNAMC.U.Ciudad de MéxicoC.P.04510México Polo Universitario de Tecnología Avanzada Universidad Nacional Autónoma de MéxicoVía de la Innovación No.410Autopista Monterrey-Aeropuertokm.10 PIITC.P.66629Apodaca Nuevo LeónMéxico

This study combines the thermodynamic analysis of a polygeneration system along with the numerical modelling of the thermal behavior of geothermal reservoirs in Mexico to exploit their *** reservoir was modeled as a porous medium assuming a five-spot well configuration and local thermal *** heat conduction-convection along with the Laplace equations were solved to compute temperature distributions,the useful life and the optimum distance between injection-extraction *** predicted temperature and pressure of the geothermal fluid at the outlet of the reservoir were exploited in the polygeneration system consisting of:(1)a Rankine cycle,(2)an absorption refrigeration cycle,and(3)a heat *** developed approach allows calculating both the optimal distance between injection-extraction wells and the global(utilization)efficiency of six arrangements(each composed by a reservoir connected to a polygeneration system)by assuming that reservoirs have a lifespan of 30 *** also show that:(a)due to the low efficiency of the Rankine cycle,very little thermal energy is converted into electrical one;(b)not only the temperature and the size are important when evaluating the power production performance of reservoirs,but also the permeability plays a fundamental role;(c)the first law efficiency of the polygeneration system ranges from 41.9%to 43.7%;(d)the utilization efficiency of the six arrangements lies in the range between 25.8%and 31%.

关键词： polygeneration system geothermal reservoir local thermal equilibrium low-to-medium enthalpy

Laser-Heated Diamond-Anvil Cell (LHDAC) in Materials Science Research

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Journal of Materials Science & Technology 2003年第6期19卷 518-525页

作者： n.V.chandra Shekar P.ch.Sahu K.Govinda Rajan Materials Science Division Indira Gandhi Centre for Atomic Research Kalpakkam 603 102 Tamil Nadu IndiaMaterials Science Division Indira Gandhi Centre for Atomic Research Kalpakkam 603 102 Tamil Nadu IndiaMaterials Science Division Indira Gandhi Centre for Atomic Research Kalpakkam 603 102 Tamil Nadu India

Laser-heated diamond-anvil cell (LHDAC) is emerging as the most suitable, economical and versatile tool for the measurement of a large spectrum of physical properties of materials under extreme pressure and temperature conditions. In this review, the recent developments in the instrumentation, pressure and temperature measurement techniques, results of experimental investigations from the literature were discussed. Also, the future scope of the technique in various avenues of science was explored.

关键词： Laser heating Diamond-anvil cell High pressure-high temperature Materials synthesis,Melting phenomena Phase equilibria

Photochemical reaction of azobenzene in solvent-swollen nafion membranes

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chinese Journal of chemistry 1996年第6期14卷 541-548页

作者： Tung, ch Guan, JQ chInESE ACAD SCI INST PHOTOG CHEMBEIJING 100101PEOPLES R CHINA

The photochemical reactions of azobenzene (AB) incorporated into different solvent-swollen nafion membranes were investigated. The location of azobenzene in water-swollen nafion membranes was different from that in methanol-swollen nafion membranes, which was responsible for the different photochemical reactions of AB. In methanol-swollen nafion membranes only transcis isomerization took place, while in water-swollen nafion membranes photochemical cyclization of AB occurred after rapid transcis isomerization. The relation between the relative quantum yields and the light intensity showed that the cyclization was a two-photo process. The numbers of AB molecules per cluster (n(AB)/cluster) in nafion membranes with different AB concentrations and different water contents were calculated. Under the experimental condition two competitive photocyclization mechanisms were suggested by n(AB)/cluster in nafion membranes, relative quantum yields of the cyclization, and the change of the ratio of benzidine to benzo[c]cinnoline.

关键词： nafion photochemical reaction azobenzene

Contrasting plant growth performance of invasive polyploid and native diploid Prosopis is mediated by the soil bacterial community

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Ecological Processes 2023年第1期12卷 193-203页

作者： Rishabh Kaushik Meesha Sharma ch.V.Ramana ch.Sasikala Maharaj K.Pandit Jealott’s Hill International Research Centre WarfieldBracknell RG426EYEnglandUK Department of Environmental Studies University of DelhiDelhi 110007India Department of Plant Sciences School of Life SciencesUniversity of HyderabadP.O.Central UniversityHyderabad 500046India Bacterial Discovery Laboratory Centre for EnvironmentInstitute of Science and TechnologyJ.N.T.University HyderabadKukatpallyHyderabad 500085India Jindal School of Environment&Sustainability OP Jindal Global UniversitySonipatHaryana 131001India

Background Soil microbial communities affect above-ground plant diversity and community composition by influencing plant growth *** studies have tested the effect of soil bacterial microbiome on growth performance of native and invasive plants,but the influence of specific bacterial isolates has not been ***,we investigated the effects of soil bacterial exclusion by soil sterilization and by inoculation of Streptomyces rhizobacterial isolates on the growth performance of native and invasive Prosopis *** Plant growth performance of invasive *** was significantly reduced when grown in sterilized soils,whereas native *** showed enhanced growth performance in the sterilized *** grown in the soil inoculated with the specific Streptomyces isolate from ***(PJ1),the growth performance of invasive *** was significantly enhanced while that of native *** seedlings was significantly ***,inoculation of *** and *** seedlings with Streptomyces isolate from the rhizosphere of native ***(PC1)had no significant effect on the growth performances either of *** or *** Our study reveals that invasive *** experiences positive feedback from the non-native soil bacterial community,while the native *** experiences negative feedback from its soil bacterial *** results provide fresh experimental evidence for the enemy release hypothesis,and further our understanding of the contrasting growth-promoting effects of differentially recruited microbial species belonging to the same genus(Streptomyces)in the rhizospheres of alien invasive and native plants.

关键词： Soil bacteria Streptomyces Invasive Prosopis juliflora Prosopis cineraria Soil microbiota

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Phase Evolution during the Sintering of Submicron Ti(C,n)-Based Cermets

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Rare Metals 2001年第4期20卷 248-254页

作者： Li, ch Xiong, WH Yu, LX Huazhong Univ Sci & Technol State Key Lab Plast Forming Simulat & Die & Mould Wuhan 430074 Peoples R China

The submicron powder mixtures of TiC-Tin-WC-Mo-C-ni sintered at 1400degreesC or below in vacuum were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The results showed that Mo2C formed at 800degreesC or below. Both WC and Mo2C disappeared at 1200degreesC, and Tin disappeared at 1250degreesC. In addition, the variations of lattice constants of the titanium carbonitride and nickel binder phase with sintering temperature were experimentally obtained, and the reason was analyzed.

关键词： submicron cermet phase sintering

Deep-water cirripedes colonizing dead shells of the cephalopod nautilus macromphalus from new Caledonian waters

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Integrative Zoology 2019年第6期14卷 561-575页

作者： John BUCKERIDGE TomášKOČÍ Ján SchLÖGL Adam TOMAŠOVÝch Martina KOČOVÁVESELSKÁ Earth&Oceanic Systems Group RMIT UniversityMelbourneVictoriaAustralia Ivančická581 PragueCzech Republic and Palaeontological DepartmentNatural History MuseumNational MuseumPragueCzech Republic Department of Geology and Paleontology Comenius University in BratislavaBratislavaSlovakia Institute of Earth Sciences Slovak Academy of SciencesBratislavaSlovakia Department of Paleobiology and Paleoecology Institute of Geology of the Czech Academy of SciencesPragueCzech Republic Museums Victoria MelbourneVictoriaAustralia Faculty of Science Charles University in PraguePragueCzech Republic

Fossil cephalopods are frequently encrusted by epibionts;however,determining whether encrustation occurred prior to or post-mortem to the host,and whether the final environment of deposition corresponds to the habitat of encrustation is *** present paper describes cirripede epibionts,their calcareous bases and their attachment scars on 6 post-mortem shells of nautilus macromphalus,collected from deep water off new Cale*** cirripedes have left both cemented calcareous bases of Hexelasma and scars associated with bioerosion and discoloration produced by verrucomorph *** cirripedes included a Metaverruca recta,with articulated opercular plates and organic tissue(on a shell that had been exposed on the sea floor for at least 150 years),and specimens of Hexelasma velutinum,one of which was partly attached to an internal surface of a *** disposition of verrucomorphs indicates that most nautilus shells were colonized post-mortem rather than during a floating ***,as cirripedes are known to have colonized living nautilus,some Hexelasma,preserved only as calcareous eroded bases,may represent specimens that settled on a living *** degree of bioerosion and discoloration induced by verrucomorph barnacles varies according to the surface preservation of nautilus shells,with deeper and discolored traces preserved on old and degraded *** made by verrucomorphs described here are ellipsoidal and a new ichnotaxon,Anellusichnus ellipticus,is proposed to accommodate ***,verrucomorphs and other cirripede taxa with membranous bases that were attached to pristine shells may not leave any substantial scars,and,thus,will be difficult to detect in the fossil record.

关键词： Anellusichnus ellipticus isp.nov cirripedes epibionts Hexelasma velutinum Metaverruca recta