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EPR and Magnetic Susceptibility investigation of Fe ions in B_2O_3-SrF_2 glass Matrix

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Journal of Materials Science & Technology 2002年第3期18卷 231-233页

作者： i.Ardelean g.Salvan 等 FacultyofPhysics Babes-BolyaiUniversity3400Cluj-NapocaRomania institutforPhysics TechnicalUniversityChemnitzGermany

The structural and magnetic properties of an oxide-fluoride mixed vitreous matrix 2B2O3-SrF2, were explored by using Fe impurities as probes. information about the structural units involving iron ions, their valence state, the strengths and type of interactions involving them was obtained using EPR spectroscopy and magnetic susceptibility measurements.

关键词： Boron oxide iron oxide Sr fluoride glass EPR Magnetic susceptibility

groundwater occurrence and flow patterns in the ishiagu mining area of southeastern Nigeria

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Frontiers of Earth Science 2012年第1期6卷 18-28页

作者： i.C.EZEKWE E.ODUBO g.N.CHiMA i.S.ONWUCHEKWA Department of geography and Environmental Management Niger Delta UniversityWilberforce IslandPMB 071YeneganaNigeria Department of geography and Planning Abia State UniversityPMB 2000UtumNigeria

The ishiagu area is a water scarce region and has played host to mining activities for more than four decades. Mining-related activities have become a threat to potable water supply in the area. This paper is an attempt to show the extent of this threat and in particular, investigate the regional groundwater occurrence and flow pattem based on gPS, water well and geological data. This basin- wide model can be used for further groundwater assess- ment, pollution control and contaminant management. groundwater occurs between 2.4 and 9 m in the Lekwesi- Lokpaukwu area; 1.5-3.7 m in the Ndi-Ugbugbor-Ayaragu axis and 1.2-4.6 m in the ishiagu area. Recharge areas include the Leru-Amaubiri-Lekwesi sandstone hills and the ihetutu-Ugwuajirija mine field. While the ultimate sink of contamiants is the ivo River system, other discharge axis is the ishiagu-Ayaragu axis and the Ogwor Ndi- Ugbugbor zone. An unconfined and a confined （〉 10） circulation groundwater system was inferred, and flow model reveals that a large part of ishiag-Ayaragu and Ndi- Ugbugbor part of the study area suffer polluted recharge from the Pb/Zn mining area. groundwater was also subjected to hierarchical cluster analysis and the existence of 3-4 hydrological regimes, which revealed： Unpolluted recharge areas, areas affected by polluted recharge, a deep water and shallow water circulation and mine effluents.

关键词： groundwater flow mining heavy metals,pollution cluster analysis ishiagu Nigeria

Combustion characteristics of low-quality lignite for different bed material sphericities in a circulating fluidized bed boiler:A numerical study

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Particuology 2024年第7期90卷 364-382页

作者： Barış gürel gülşah Karaca Dolgun Osman ipek Ali Keçebaş Department of Mechanical Engineering Engineering FacultySüleyman Demirel UniversityÇünürIspartaTurkey Department of Energy Systems Engineering Technology FacultyMuğla SıtkıKoçman UniversityKötekliMenteşeMuğlaTurkey

This study delves into the combustion behavior of various lignite types within a circulating fluidized bed boiler(CFBB),with a primary focus on the impact of different bed material sphericity ratios(0.5,0.7,and 0.9).Utilizing bed material with a sphericity ratio of 0.9 sourced from theÇan power plant and verified through experimentation,the research reveals several key ***,furnace temperatures tended to rise with higher sphericity ratios,albeit with variations between lignite types,particularly highlighting the complexity of this relationship in the case of gLi-Tunçbilek *** levels in the combustion chamber remained consistent across different sphericity ratios,indicating minimal influence on pressure *** combustion efficiency,especially at the bottom of the boiler,was observed at lower sphericity levels(0.5 and 0.7)forÇan lignite,as reflected in CO_(2) mole *** NO_(x) emissions generally decreased with lower sphericity,the sensitivity to sphericity varied by lignite type,with ilgın lignite showcasing low NO_(x) but high SO_(2) emissions,underscoring the intricate interplay between lignite properties,sphericity,and ***,this study advances our understanding of CFBB combustion dynamics,offering insights valuable for optimizing performance and emissions control,particularly in lignite-based power.

关键词： Circulating fluidized bed boiler Computational particle fluid dynamics method Particle sphericity ratios NO_(x)and SO_(2)emissions Energy production efficiency

investigation of the transformation of organic matter of carbonate deposits of the Semiluksky-Mendymsky horizon under hydrothermal conditions

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Petroleum 2024年第2期10卷 216-223页

作者： S.M.Petrov A.i.Lakhova E.g.Moiseeva A.g.Safiulina institute of Petroleum Chemistry and NanotechnologiesKazan National Research Technological UniversityKazan420015Russia institute of geology and Oil and gas Technologies Kazan Federal UniversityKazan420008Russia

The paper presents the results of studies on the transformation of the organic matter of siliceous-clayey carbonate rocks of the Semiluksko-Mendymsky horizon of the Romashkino oil field in a hydrothermal fluid for an hour(with a water-to-rock ratio of 33)at 340℃and 380℃and pressu res of 17 and 20 *** a result of hydrothermal treatment,at 340℃and 17 MPa,based on nitrogen porosimetry and electron microscopy data,transformations of rock-forming minerals in the rock are *** lead to an increase in the volume and average diameter of mesopores in it and the formation of micropores,as well,which improve its filtration *** the same time,the amount of kerogen in the composition of the organic matter decreases and the yield of the petroleum hydrocarbon extract increases,in which,according to the SARA analysis,the content of asphaltenes increases and the content of resins,aromatic and saturated hydrocarbons *** the composition of aroatic hydrocarbons,the proportion of a lkyltri methyl benzenes and dibenzothiophenes increases,phenanthrene homologues appear,and in the composition of saturated hydrocarbons,the amount of iso-structure alkanes decreases relative to the content of linear *** the temperature and pressure of the hydrothermal fluid to 380℃and 20 MPa increases the degree of kerogen conversion from 12.4%to 23.6%.At the same time,changes occurring in the component composition of petroleum hydrocarbon extracts remains similar to the experiments carried out at 340℃and 17 MPa;the content of naphthalenes decreases,the content of dibenzothiophenes increases and C_(11)-C_(17),C_(19)-C_(22)alkyltrimethylbenzenes *** to iR spectroscopy,with increasing temperature and pressure of the hydrothermal fluid the intensity of the absorption bands of the aromatic ring,aliphatic fragments,and oxygen-containing groups increases in resins;the structural-group composition of asphaltenes changes little:aromaticity and the content of conde

关键词： Carbonate deposits Organic matter Hydrothermal fluid Mobile hydrocarbons

Chromomagnetic and chromoelectric dipole moments of quarks in the reduced 331 model

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Chinese Physics C 2021年第11期45卷 11-24页

作者： A.i.Hemandez-Juarez g.Tavares-Velasco A.Moyotl Facultad de Ciencias Fisico Matematicas Benemerita Universidad Autonoma de PueblaApartado Postal 1152PueblaPueblaMexico ingenieria en Mecatronica Universidad Politecnica de PueblaTercer Carril del Ejido Serrano s/nSan Mateo CuanalaJuan C.BonillaPueblaPueblaMexico

The one-loop contributions to the chromomagnetic dipole momentˆμt(q2)and electric dipole momentˆd t(q2)of the top quark are calculated within the reduced 331 model(RM331)for non-zero *** is argued that the results are gauge independent and thus represent valid observable *** the RM331,ˆμt(q2)receives new contributions from two heavy gauge bosons,namely Z′and V±,and one neutral scalar boson h2,along with a new contribution from the standard model's Higgs boson via flavor changing neutral *** latter,which is also mediated by the Z′gauge boson and the scalar boson h2,can provide a non-vanishingˆd t(q2)if there is a CP-violating *** analytical results are presented in terms of both Feynman parameter integrals and Passarino-Veltman scalar functions,which are useful to cross-check the numerical ***ˆμt(q2)andˆd t(q2)are numerically evaluated for parameter values still allowed by the constraints from experimental *** is found that the new one-loop contributions of the RM331 to the real(imaginary)part ofˆμt(q2)are of the order of 10−5(10−6),which means at least three orders of magnitude smaller than the standard model prediction but larger than the predictions of other models of new *** the RM331,the dominant contribution arises from the V±gauge boson for‖q‖in the 30-1000 geV interval and a mass mV of the order of a few hundreds of *** forˆd t(q2),it receives its largest contribution from h2 exchange and can reach values of the order of 10−19,i.e.,smaller than the contributions predicted by other standard model extensions.

关键词： chromomagnetic chromoelectric 331 models

Dynamic Failure of Shock-Loaded glass

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Chinese Physics Letters 1997年第7期14卷 538-541页

作者： HE Hong-liang JiN Xiao-gang JiNg Fu-qian g.i.Kanel Laboratory for Shock Wave and Detonation Physics Research Southwest Institute of Fluid PhysicsChengdu 610003 institute for High Temperatures Russian Academy of SciencesMoscow 127412Russia Federation

Failure wave generations on both impacted surface and internal surface inside the sample have been observed for K9 glass under planar shock wave loading,which demonstrates that formation of failure wave is a process related to the surface microcracks nuclei *** on these observations,a hypothesis is suggested that the large local strains resulting from the rearrangement of SiO4 tetrahedral within the permanent densification region behind the shock wave front and then strains releasing due to the surface microcracks developing could be responsible for the failure wave generation.

关键词： surface wave shock

Clinical and cost impact of intravenous proton pump inhibitor use in non-iCU patients

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World Journal of gastroenterology 2010年第8期16卷 982-986页

作者： Soumana C Nasser Jeanette g Nassif Hani i Dimassi Department of Pharmacy Practice School of PharmacyLebanese American University

AiM:To assess the appropriateness of the indication and route of administration of proton-pump-inhibitors (PPis) and their associated cost impact. METHODS:Data collection was performed prospec-tively during a 6-mo period on 340 patients who re-ceived omeprazole intravenously during their hospital stay in non-intensive care floors. Updated guidelines were used to assess the appropriateness of the indication and route of administration. RESULTS:Complete data collection was available for 286 patients which were used to assess intravenous (iV) PPis utilization. Around 88% of patients were receiving PPis for claimed stress ulcer prophylaxis (SUP) indication; of which,only 17% met the guideline criteria for SUP indication,14% met the criteria for non-steroidal-anti-inflammatory drugs-induced ulcer prophylaxis,while the remaining 69% were identifi ed as having an unjustified indication for PPi use. Theinitiation of iV PPis was appropriate in 55% of pa-tients. Half of these patients were candidates for switching to the oral dosage form during their hos-pitalization,while only 36.7% of these patients were actually switched. The inappropriate initiation of PPis via the iV route was more likely to take place on the medical floor than the surgical floor (53% vs 36%,P = 0.003). The cost analysis associated with the appro-priateness of the indication for PPi use as well as the route of administration of PPi revealed a possible saving of up to $17 732.5 and $14 571,respectively. CONCLUSiON:This study highlights the over-utili-zation of iV PPis in non-intensive care unit patients. Restriction of iV PPi use for justified indications and route of administration is recommended.

关键词： Cost saving Lebanon Non-intensive care unit patients Omeprazole Over-utilization Proton-pump-inhibitors Stress ulcer prophylaxis

Analysis of monitored ground support and rock mass response in a longwall tailgate entry

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international Journal of Mining Science and Technology 2018年第1期28卷 43-51页

作者： g.S.Esterhuizen D.F.gearhart i.B.Tulu NiOSH Pittsburgh Mining Research Division PittsburghPA 15236USA West Virginia University MorgantownWV 26506USA

A comprehensive monitoring program was conducted to measure the rock mass displacements, support response, and stress changes at a longwall tailgate entry in West *** was initiated a few days after development of the gateroad entries and continued during passage of the longwall panels on both sides of the *** included overcore stress measurements of the initial stress within the rock mass, changes in cable bolt loading, standing support pressure, roof deformation, rib deformation,stress changes in the coal pillar, and changes in the full three-dimensional stress tensor within the rock mass at six locations around the monitoring *** the passage of the first longwall, stress measurements in the rock and coal detected minor changes in loading while minor changes were detected in roof *** a result of the relatively favorable stress and geological conditions, the support systems did not experience severe loading or rock deformation until the second panel approached within 10–15 m of the instrumented *** reaching the peak loading at about 50–75 mm of roof sag, the cable bolts started to unload, and load was transferred to the standing *** standing support system was able to maintain an adequate opening inby the shields to provide ventilation to the first crosscut inby the face, as *** results were used to calibrate modeled cable bolt response to field data, and to validate numerical modeling procedures that have been developed to evaluate entry support *** is concluded that the support system was more than adequate to control the roof of the tailgate up to the longwall face *** monitoring results have provided valuable data for the development and validation of support design strategies for longwall tailgate entries.

关键词： Longwall mining Support Tailgate Monitoring Coal mining

Temporal Behaviour of a Corner Separation in a Radial Vaned Diffuser of a Centrifugal Compressor Operating near Surge

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Journal of Thermal Science 2013年第6期22卷 555-564页

作者： A.Marsan i.Trébinjac S.Coste g.Leroy Laboratoire de Mécanique des Fluides et d'Acoustique UMR CNRS 5509 cole Centrale de Lyon Turbomeca Safran group

The temporal behaviour of a flow separation in the hub-suction side comer of a transonic diffuser is studied thanks to unsteady numerical simulations based on the phase-lagged approach. The validity of the numerical re- sults is confn＇med by comparison with experimental unsteady pressure measurements. An analysis of the instan- taneous skin-friction pattern and particles trajectories is presented. it highlights the topology of the separation and its temporal behaviour. The major result is that, despite of a highly time-dependent core flow, the separation is found to be a ＂fixed unsteady separation＂ characterized by a fixed location of the main saddle of the separation but an extent of the stall region modulated by the pressure waves induced by the impeller-diffuser interaction.

关键词： Corner Separation Radial Vaned Diffuser Centrifugal Compressor Surge