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Utilizing a novel fiber optic technology to capture the axial responses of fully grouted rock bolts

Journal of Rock Mechanics and Geotechnical Engineering 2018年第2期10卷 222-235页

作者： Nicholas Vlachopoulos daniel cruz Bradley Forbes Department of Civil Engineering Royal Military College of Canada Department of Geological Sciences and Geological Engineering Queen's UniversityKingston

Rock bolts are one of the primary support systems utilized in underground excavations within the civil and mining engineering industries. Rock bolts support the weakened rock mass adjacent to the opening of an excavation by fastening to the more stable, undisturbed formations further from the excavation. The overall response of such a support element has been determined under varying loading conditions in the laboratory and in situ experiments in the past four decades; however, due to the limitations with conventional monitoring methods of capturing strain, there still exists a gap in knowledge associated with an understanding of the geomechanical responses of rock bolts at the microscale. In this paper, we try to address this current gap in scientific knowledge by utilizing a newly developed distributed optical strain sensing(DOS) technology that provides an exceptional spatial resolution of 0.65 mm to capture the strain along the rock bolt. This DOS technology utilizes Rayleigh optical frequency domain reflectometry(ROFDR) which provides unprecedented insight into various mechanisms associated with axially loaded rebar specimens of different embedment lengths, grouting materials, borehole annulus conditions, and borehole diameters. The embedment length of the specimens was found to be the factor that significantly affected the loading of the rebar. The critical embedment length for the fully grouted rock bolts(FGRBs) was systematically determined to be430 mm. The results herein highlight the effects of the variation of these individual parameters on the geomechanical responses FGRBs.

关键词： Fiber optic technology Fully grouted rock bolts Load transfer Stress distribution

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Interactions of primary neuroepithelial progenitor and brain endothelial cells: distinct effect on neural progenitor maintenance and differentiation by soluble factors and direct contact

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Cell Research 2007年第7期17卷 619-626页

作者： Miguel A Gama Sosa Rita De Gasperi Anne B Rocher Gissel M Perez Keila Simons daniel E cruz Patrick R Hof Gregory A Elder Departments of Psychiatry Research and Development Service James J. Peters Department of Veterans Affairs Medical Center 130 West Kingsbridge Road Bronx New York 10468 USA Neuroscience Mount Sinai School of Medicine of New York University New York NY Department of Research and Development Service James J. Peters Department of Veterans Affairs Medical Center 130 West Kingsbridge Road Bronx New York 10468 USA

Neurovascular interactions are crucial for the normal development of the central nervous system. To study suchinteractions in primary cultures, we developed a procedure to simultaneously isolate neural progenitor and endothelialcell fractions from embryonic mouse brains. Depending on the culture conditions endothelial cells were found to favormaintenance of the neuroprogenitor phenotype through the production of soluble factors, or to promote neuronal differ-entiation of neural progenitors through direct contact. These apparently opposing effects could reflect differential cellularinteractions needed for the proper development of the brain.

关键词： differentiation culture endothelial cells neuroepithelial cells

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Origin of Erosion and Hydraulic Problems of the San Roque Underground Arched Culvert Channel and Its Relationship with the Maximum Flow Rate and the Maximum Permissible Velocity

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Journal of Water Resource and Protection 2020年第12期12卷 1123-1139页

作者： Martín Mundo-Molina daniel Hernández-cruz Academic Group Science and Engineering Engineering Faculty Chiapas State University Chiapas Mexico

This work presents the hydrologic estimations of the hydraulic underground arched culvert channel (UACC) in Sabinal Basin, Chiapas, México and the hydrological problems associated with it, such as the erosion phenomenon and abrasion cavity formation in it. On the other hand, the maximum flows that the UACC could transport were analyzed, concluding that it no longer has the hydraulic capacity to transport the flow rate associated to return periods equal to or greater than five years and that maximum permissible velocity UACC’s bottom is 3 m/s.

关键词： Collapse Underground Arched Culvert Channel Maximum Flow Rate Maximum Permissible Water Velocity Open Channel Bottom Erosion

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Modified combustion synthesis of g-LiAlO_2 using metal oxides

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Transactions of Nonferrous Metals Society of China 2018年第9期28卷 1793-1800页

作者： daniel cruz H.B.ORTIZ-OLIVEROS L.M.PéREZ-DíAZ R.M.FLORES-ESPINOSA G.ROSANO-ORTEGA Facultad de Ingeniería Química Benemérita Universidad Autónoma de Puebla14 Sur y San ClaudioCiudad UniversitariaC.P.72570Cd.PueblaMéxico Instituto Nacional de Investigaciones Nucleares Dirección de Investigación TecnológicaApartado Postal 18-102711801 MéxicoDFMéxico Universidad Popular Autónoma del Estado de Puebla 21 Sur no.1103Colonia SantiagoC.P.72410PueblaMéxico

An alternative solution for the direct formation of?-LiAlO2 was presented by a modified combustion method,to apply it to rather simple systems,utilizing non-oxidizer compounds such as Al2O3 and LiOH,and urea as ***2 was prepared via non-stoichiometric 1:1,1.5:1 and 2:1 of Li/Al molar ratios at 900 and 1000°C for 5 *** and structural characterization ofγ-LiAlO2 was ***,the effect of different Li/Al molar ratios on material morphology and its stability before high gamma radiation gradients was *** results showed that the crystal structures of the obtained powders wereγ-LiAlO2 and?-LiAlO2,depending on the Li/Al molar *** results obtained demonstrate that?-LiAlO2 microbricks,polyhedral and laminar shapes can be successfully synthesized with the proposed method and without any subsequent ***,gamma irradiation showed that the?-LiAlO2 obtained does not decompose,forming only small amounts of *** can be established that the irradiation produces consolidation,which is not favourable for an efficient extraction of ***,it could be demonstrated that nitrate precursors are not necessary in the combustion method to produceγ-LiAlO2 with high purity.

关键词： urea oxide combustion lithium aluminate ceramic

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Methodology for Volumetric Measuring Transport of River Sand, in a Laboratory Channel with Mobile Bottom

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Engineering（科研） 2018年第11期10卷 759-768页

作者： Martín Mundo-Molina Jose Luis Pérez-Díaz daniel Hernández-cruz Engineering Faculty Chiapas State University Tuxtla Gutiérrez Chiapas Mexico

Most public universities in Latin America and Mexico lack laboratories for measuring sediment transport or to do academic activities. The Research Center of the engineering faculty of Chiapas state university (UNACH by its acronym in Spanish) designed a portable prismatic channel for teaching and researching the sediment transportation in rivers. This paper presents the method to measure river sand transportation in a laboratory channel with a mobile bottom and presents the results of twenty-seven experiments done in the portable channel, using nine different slope inclinations and 27 flow and water speed values. The three main results are the following: 1) The construction of the channel with variable slopes, to experiment and measure sediment transportation. 2) A method developed for measuring the volume of sediment in a laboratory. 3) In a channel with a bottom slope of 0.071, a water flow of 2 l/s and a water speed of 1.77 m/s, the volume of transported sediment was 0.015 m3;in a channel with a bottom slope of 0.44, a water flow of 2 l/s and a water speed of 0.788 m/s, the volume of transported sediment was 0.006 m3;in a channel with the bottom slope of 0.024, a water flow of 2 l/s and a water speed of 0.62 m/s, the transported sediment was 0 m3.

关键词： Volumetric Measurement of Sediment Sediment Transport Transportable Prismatic Channel Measurement of Sediment in Laboratory

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Detecting Climate Change in Using Extreme Data from Two Surface Weather Stations: Case Study Valle of Comitan and La Esperanza, Chiapas, Mexico

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Journal of Water Resource and Protection 2021年第12期13卷 1061-1075页

作者： Martín Mundo-Molina Eber A. Godinez-Gutiérrez José Luis Pérez-Díaz daniel Hernández-cruz Investigation Centre Faculty of Engineer Autonomous University of Chiapas Chiapas Mexico

The study area is located between the cities of Comitan (16°10'43"N and 92°04'20''W) a city with 150,000 inhabitants and La Esperanza (16°9'15''N and 91°52'5''W) a town with 3000 inhabitants. Both weather stations are 30 km from each other in the Chiapas State, México. 54 years of daily records of the series of maximum (tmax) and minimum temperatures (tmin) of the weather station 07205 Comitan that is on top of a house and 30 years of daily records of the weather station 07374 La Esperanza were analyzed. The objective is to analyze the evidence of climate change in the Comitan valley. 2.07% and 19.04% of missing data were filled, respectively, with the WS method. In order to verify homogeneity three methods were used: Standard Normal Homogeneity Test (SNHT), the Von Neumann method and the Buishand method. The heterogeneous series were homogenized using climatol. The trends of tmax and tmin for both weather stations were analyzed by simple linear regression, Sperman’s rho and Mann-Kendall tests. The Mann-Kendal test method confirmed the warming trend at the Comitan station for both variables with ZMK statistic values equal to 1.57 (statistically not significant) and 4.64 (statistically significant). However, for the Esperanza station, it determined a cooling trend for tmin and a slight non-significant warming for tmax with a ZMK statistic of -2.27 (statistically significant) and 1.16 (statistically not significant), for a significance level α = 0.05.

关键词： Detecting Climate Change in Using Extreme Data from Two Surface Weather Stations: Case Study Valle of Comitan and La Esperanza Chiapas Mexico

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Testing and modelling of transient adhesion phenomena in rolling-sliding contacts

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Friction 2024年第5期12卷 1016-1027页

作者： daniel KVARDA Alexander MEIERHOFER Klaus SIX Faculty of Mechanical Engineering Brno University of TechnologyBrno61669Czech Republic Virtual Vehicle Research GmbH Graz8010Austria

Transient adhesion effects in rolling–sliding contacts influence all aspects of train–track *** is of high importance specifically when these effects result in critically low adhesion,which poses a risk to traction and braking of railway *** study presents a model that can replicate the transient changes of the coefficient of adhesion with tested water and solid particle *** experimental data for the model are measured using a commercial ball-on-disc *** experimental results showed a liquid reservoir in front of the contact area that slowly reduces in *** observation was used in the modelling approach to divide the calculation into two stages where the reservoir is present and when it *** model was able to reproduce the occurrence of low adhesion region seen in experimental results with different particle concentrations.

关键词： coefficient of adhesion tribology transient effects wheel-rail contact

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Energy model based on solar potential and the production of electrical energy through living plants’photosynthesis

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Clean Energy 2024年第3期8卷 116-126页

作者： Raymond daniel Rodriguez Martinez Department of Industrial Production Faculty of EngineeringUniversidad Metropolitana1073 CaracasVenezuela

Developing a sustainable energy model is imperative considering the current trend towards decarbonizing sectors *** this purpose,Venezuela was used as a reference to propose an energy model focused on taking advantage of plant photosynthesis through microbial-vegetable fuel cells together with an agro-photovoltaic system to enhance energy and agricultural *** production from the cells was estimated using an average power density of 264 mW/m^(2) over 4%of the areas destined for crops in the entire Venezuelan region,obtaining an annual production of 19.889 GWh/*** contrast,the energy production of the agro-photovoltaic system was modelled using PVsyst software on 50%of the area used for the cells distributed throughout the states of Anzoátegui,Guárico,Monagas and Portuguesa according to their meteorological conditions,solar irradiation and agricultural activity,resulting in 3703417 GWh/*** resulting whole system proved to be able to cover>10 times the installed electricity generation capacity at a national level and,together with the tremendous scalability of the microbial fuel cells,it shows that Venezuela has a high potential for the production and distribution of clean energy.

关键词： ecosystems microbial fuel cell microorganisms renewable sustainability

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Beyond the code:the role of histone methylation in cancer resistance and therapy

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Signal Transduction and Targeted Therapy 2024年第7期9卷 2837-2839页

作者： daniel Noerenberg Frederik Damm Charité–Universitätsmedizin Berlin corporate member of Freie Universität BerlinHumboldt Universität zu Berlinand Berlin Institute of HealthDepartment of HematologyOncologyand Cancer ImmunologyBerlinGermany German Cancer Consortium(Deutsches Konsortium für Translationale Krebsforschung DKTK)Partner SiteBerlinGermany

In a recently published paper in Nature,Yamagishi et *** a comprehensive exploration on the mechanistic basis and subsequent emergence of resistance of targeting histone H3 lysine trimethylation(H3K27me3)using the EZH... 详细信息

关键词： EZH2 resistance

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Plant-microbial fuel cell for electrical generation through living plants: an internal resistance insight into the plant species used

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Clean Energy 2024年第5期8卷 45-53页

作者： Raymond daniel Rodriguez Martinez Department of Industrial Production Faculty of EngineeringUniversidad Metropolitana1073 CaracasVenezuela

Climate change is a global threat,the presence of which has encouraged the development and implementation of renewable energies,including plant–microbial fuel cells,which could generate 6629568–33147840 MWh per year due to their large-scale *** of the main challenges associated with microbial cells is internal resistance—a parameter whose magnitude is influenced by sev-eral *** the case of plant–microbial fuel cells,adding a plant positively affects the mitigation of internal ***,the species employed is expected to play an important *** the present study,the objective was to determine as a general reference the internal resistance of cells using various plant species,among which were tomato(Solanum lycopersicum),black beans(Phaseolus vulgaris),aloe vera(Aloe vera),corn(Zea mays),and moss(Dicranidae).For this purpose,an experimental procedure was carried out to compare the manual voltage measurements with a free cell concerning the voltage obtained by adding an external resistor in *** internal resistance values were determined as a function of the measured voltage,obtaining 177,179,175,324,and 233 kΩfor aloe vera,corn,tomato,black beans,and moss,*** this,it was shown that the roots of the plants represent an essen-tial addition to the internal resistance of the cell in the short *** contrast,plants with a C4 photosynthetic metabolism are more favourable,while C3 plants can also benefit from internal resistance during a more extended period of rhizodeposition.

关键词： climate change energy microorganism renewable source voltage

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