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Isotopic Variations of oxygen (δ^(18)o) in Benthic Foraminifera under Antiestuarine Conditions in the Colorado river delta

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open Journal of Geology 2018年第2期8卷 104-123页

作者： miguel a.santa rosa-del río Ismael Yarbuh rigoberto Guardado-France ronald M.Spelz raúl Herrera-Gutiérrez Karla Mejia-Pina miguel Agustín Tellez-Duarte Luis Antonio Cupul-Magana Universidad Autónoma de Baja California Facultad de Ciencias MarinasArea de GeologíaEnsenadaMéxico

Benthic foraminifera are excellent environmental indicators;CaCo3 test records the isotopic concentration of their surroundings and can be used to analyze environmental changes that occur during a certain time period. Stable isotopes, particularly those of oxygen (δ18o), are useful for interpreting ancient environments, given that they are used as “proxy” environmental variables (temperature and salinity). In this study, we provide ranges of isotopic variation in benthic foraminifera communities from the Colorado river delta. Four sampling campaigns were conducted in one year (2009-2010) in the adjacent subtidal zone of Baja California. Four transects with a total of sixteen sample station were drawn perpendicular to the coastline. Here, we recorded the following in situ: sand-type, salinity, and temperature. In the laboratory, 300 individuals per sample were separated, and sub-samples were taken for isotopic analysis. Data was processed using the software’s r 2.12.2, PAST 1.81 and Arc Map 9.3. Forty species were identified in the dead assemblages (Thanatocoenosis), whereas thirteen species were found in the living assemblages (Biocoenosis). The most abundant species in both communities belong to the genera Ammonia and Cribroelphidium. In the living assemblages, isotopic variation −2.15% to 5.94% within a temperature interval of 11°C, indicated antiestuarine conditions. In the dead assemblages, isotopic composition −3.04 to −0.74 served as a sign of estuarine conditions prior to damming.

关键词： Stable Isotopes Living Assemblages Dead Assemblages Upper Gulf of California

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Advancing respirable coal mine dust source apportionment:a preliminary laboratory exploration of optical microscopy as a novel monitoring tool

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International Journal of Coal Science & Technology 2024年第2期11卷 222-233页

作者： Nestor santa Emily Sarver Department of Mining and Minerals Engineering Virginia TechBlacksburgVA 24061USA

Exposure to respirable coal mine dust(rCMD)can cause chronic and debilitating lung ***-time monitoring capabilities are sought which can enable a better understanding of dust components and *** many underground mines,rCMD includes three primary components which can be loosely associated with three major dust sources:coal dust from the coal seam itself,silicates from the surrounding rock strata,and carbonates from the inert‘rock dust’products that are applied to mitigate explosion hazards.A monitor which can reliably partition rCMD between these three components could thus allow source *** tracking silicates,specifically,could be valuable since the most serious health risks are typically associated with this component-particularly if abundant in crystalline *** a monitoring concept based on field microscopy,and following up on prior research using polarized light,the aim of the current study was to build and test a model to classify respirable-sized particles as either coal,silicates,or *** model development,composite dust samples were generated in the laboratory by successively depositing dust from high-purity materials onto a sticky transparent substrate,and imaging after each deposition event such that the identity of each particle was known a *** testing followed a similar approach,except that real geologic materials were used as the source for each dust *** showed that the model had an overall accuracy of 86.5%,indicating that a field-microscopy based moni-tor could support rCMD source apportionment and silicates tracking in some coal mines.

关键词： Polarized light microscopy Image processing Dust monitoring respirable silica Coal mining

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Lower Continental Crusts Involved in the Alpine orogeny:New Insight from the santa Lucia Nappe Metasediments(Corsica,France)

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Acta Geologica Sinica(English Edition) 2024年第4期98卷 904-920页

作者： Chiara FrASSI Maria DI rosa Luca PANDoLFI Michele MArroNI Dipartimento di Scienze della Terra Universitàdi PisaVia Santa Maria 5356126 PisaItaly Istituto di Geoscienze e Georisorse IGG-CNRVia Moruzzi50124 PisaItaly

In the Alpine Corsica(France),the santa Lucia Nappe represents a peculiar unit preserving the unique relicts of Paleozoic lower to medium continental *** consists of composite basement affected by Permian granulite facies metamorphic conditions unconformably covered by a Late Cretaceous clastic sequence(Tomboni Conglomerate and Tralonca Flysch)affected by polyphase deformation and *** this work,we present a new reconstruction of the deformation events registered by the Tralonca Flysch during the Alpine *** D1 phase was testified by rare isoclinal *** D2 phase produced a continuous foliation and a map-scale sheath-fold with a top-to-W sense of *** D3 phase produced E-verging non-cylindrical folds and S3 crenulation cleavage that is not associated to metamorphic *** present the first temperature-pressure-deformation(P-T-d)path for the Tralonca Flysch,demonstrating that the santa Lucia Nappe underwent accretion and then first stage exhumation in the Alpine wedge during the D1 phase with pressure and temperature peaks both occurred under blueschist metamorphic *** D2 phase occurred at lower pressure-temperature conditions during a second stage *** pressure-temperaturedeformation path is comparable with those of the Lower Units(i.e.,the subducted continental units of Alpine Corsica)suggesting a common geodynamic history.

关键词： blueschist-facies metamorphism P-T-d path santa Lucia Nappe Corsica Alpine orogeny

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reduction Discoloration of reactive Dyed Cotton Waste and Chemical recycling via Ionic Liquid

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Journal of renewable Materials 2024年第9期12卷 1557-1571页

作者： Aline Ferreira Knihs Larissa Klen Aragão miguel Angelo Granato Andrea Cristiane Krause Bierhalz rita de Cassia Siqueira Curto Valle Department of Textile Engineering Federal University of Santa CatarinaBlumenau89036-256Brazil

The textile industry generates large volumes of waste throughout its production process. Most of this waste is colored, therefore, discoloration is an important step toward recycling and reusing this waste. This study focused on the chemical reductive discoloration of textile waste composed of cotton dyed with reactive dye. The experimental design demonstrated the significant influence of the concentration of reducing agent and time of reaction on the degree of whiteness of the cotton fibers. The concentration of the alkaline agent was not significant in the process. The optimization of the reaction conditions lead to Berger degree of 50.5 ± 3.5. The discolored cotton was chemically recycled through dissolution in ionic liquid 1-ethyl-3-methylimidazolium chloride and regeneration in film form in water. The microstructure of the regenerated cellulose films was evaluated by Scanning Electron Microscopy (SEM) indicating complete dissolution and uniform regeneration. The discoloration process reduced the polymerization degree and crystallinity index of the cotton fibers but retained the cellulose I structure. The dissolution and cellulose regeneration process results in transparent films with an amorphous structure. The thermal behavior, evaluated by thermogravimetric analysis, indicated that residues and regenerated film presented a main decomposition step. The maximum decomposition rate temperature of the regenerated films was approximately 40°C lower than the cotton fibers, which correlates well with the reduction in polymerization degree and amorphous structure. In general, the study demonstrated that textile cotton waste dyed with reactive dyes can be chemically discolored to form transparent and amorphous films, contributing to the development of sustainable strategies for the textile industry.

关键词： reactive dyed cotton waste reactive discoloration ionic liquid dissolution and regeneration recycling and reusing

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rheological and stability analysis of cement pastes incorporating silica-based wastes

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Particuology 2024年第6期89卷 144-152页

作者： Julia da rosa Martins Janaíde Cavalcante rocha Dachamir Hotza Luciano Senff Graduate Program in Materials Science and Engineering(PPGMAT) Federal University of Santa Catarina(UFSC)Florianópolis88040-900SCBrazil Graduate Program in Civil Engineering(PPGEC) Federal University of Santa Catarina(UFSC)Florianópolis88040-900SCBrazil Graduate Program in Chemical Engineering(PoSENQ) Federal University of Santa Catarina(UFSC)Florianópolis88040-900SCBrazil Department of Mobility Engineering Federal University of Santa Catarina(UFSC)Joinville89219-600SCBrazil

This study investigates the influence of waste characteristics,especially zeta potential,on the properties of cement pastes and *** focus is to evaluate the impact of the zeta potential of cement particles and waste materials on the sedimentation speed,rheology,and hardening time of stabilized cement *** Cement II F 40,retarder additive,silica,and fly ash were used in the *** pastes were prepared,and during the stabilization period,their rheological properties and pH were *** zeta potential and sedimentation speed of the cement and waste particles were measured at the pH that the pastes presented during the entire stabilization *** the stabilization period,the pastes were subjected to the hardening time *** zeta potential analyses revealed diverse values for the different powder types,with the cement particles exhibiting a zeta potential of−3.0 mV,the silica particles exhibiting−10.5 mV,and the fly ash particles exhibiting−20.3 *** influence of the high zeta potential modulus was observed on the sedimentation speed,with the solution containing fly ash exhibiting a speed of 40.01μm/s,whereas the solution containing only cement exhibited a speed of 99.38μm/*** the pastes,the results indicate that the presence of fly ash particles with a significantly negative zeta potential led to a 16%reduction in hardening time compared to particles with a lower modulus of zeta *** tests showed that the inclusion of fly ash particles prevented the formation of *** the zeta potential influenced agglomerate formation and hardening time,it was found to have no effect on yield stress or viscosity.

关键词： Wastes Zeta potential Setting time rheometry

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Best management practices to reduce soil erosion and change water balance components in watersheds under grain and dairy production

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International Soil and Water Conservation research 2024年第1期12卷 121-136页

作者： Thais Palumbo Silva Danielle Bressiani Éderson Diniz Ebling Josémiguel reichert Soil Science of Federal University of santa Maria Roraima Avenuenumber 1000CEP:97.105-900Santa MariaRio Grande do SulBrazil Technological Development Center Federal University of PelotasGomes Carneiro Streetnumber 1CEP:96010-610PelotasRio Grande do SulBrazil Department of Soil Federal University of Santa MariaCampus Universitário s/nCEP 97.105-900Santa MariaRio Grande do SulBrazil

Soil erosion and sedimentation are among the most serious global environmental *** and water conservation measures have been proven effective ways to reduce soil *** objective of this study was to evaluate the impact of three approaches of soil and water conservation measures(soil management,vegetative measures,and structural practices)on soil erosion and water balance of two paired agricultural watersheds located in Southern *** and sediment monitoring was carried out from 2016 to 2019 in the two small paired agricultural watersheds;called North watershed(NW)and South watershed(SW).Modeling using Soil&Water Assessment Tool(SWAT)was performed to simulate individual(nine scenarios)and combined(four scenarios)best management practices(BMPs),by including the three *** the nine individual BMP scenarios,the most effective in reducing soil erosion was crop rotation and cover crop(sediment yield,SY,reduction of 38.4 for NW,and 28.8%for SW).Among the four combined scenarios,the association of all conservation approaches was the most effective in reducing soil erosion(SY reduction of 46 for NW,and 41.5%for SW),followed by the vegetative measures scenario(SY reduction of 43.5 and 34.1%for NW and SW).All combined scenarios increased infiltration and subsurface water components,and decreased surface *** findings of this study can help farmers and policymakers choosing appropriate BMPs to reduce current soil erosion problems and promote water and soil conservation.

关键词： Agricultural hydrology Conservation measures SWAT Subtropical watersheds

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optimal Design of Hybrid Microgrid in Isolated Communities of Ecuador

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 488-499页

作者： Luis A.Pesantes ruben Hidalgo-León Johnny rengifo miguel Torres Jorge Aragundi JoséCordova-Garcia Luis F.Ugarte Facultad de Ingeniería en Electricidad y Computación of Escuela Superior Politécnica del Litoral(ESPoL)University GuayaquilEcuador Department of Electrical Engineering at Universidad Técnica Federico santa María SantiagoChile IEEE

In rural territories, the communities use energy sources based on fossil fuels to supply themselves with electricity, which may address two main problems: greenhouse gas emissions and high fuel prices. Hence, there is an opportunity to include renewable resources in the energy mix. This paper develops an optimization model to determine the optimal sizing, the total annual investment cost in renewable generation, and other operating costs of the components of a hybrid microgrid. By running a k-means clustering algorithm on a meteorological dataset of the community under study, the hourly representative values become input parameters in the proposed optimization model. The method for the optimal design of hybrid microgrid is analyzed in six operating scenarios considering:(1) 24-hour continuous power supply;(2) load shedding percentage;(3) diesel power generator(genset) curtailment;(4) the worst meteorological conditions;(5) the use of renewable energy sources including battery energy storage systems(BESSs);and(6) the use of genset. A mathematical programming language(AMPL) tool is used to find solutions of the proposed optimization model. results show that the total costs of microgrid in the scenarios that cover 100% of the load demand(without considering the scenario with 100% renewables) increase by over 16% compared with the scenario with genset operation limitation. For the designs with power supply restrictions, the total cost of microgrid in the scenario with load shedding is reduced by over 27% compared with that without load shedding.

关键词： Battery energy storage system(BESS) isolated community microgrid renewable energy optimization

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Effect of Nanostructures Addition and Enhancement of Poly (Vinylidene Difluoride) (PVDF) Energy Harvesting

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Materials Sciences and Applications 2024年第7期15卷 228-244页

作者： omar Peña-oliveras Brenda Javier-Boodhan Anthony La.santa Juan Gonzalez-Sanchez Division of Science Technology and Engineering Universidad Ana G. Mndez Carolina Campus Carolina Puerto Rico Department of Electronics University of Puerto Rico Bayamon Campus Bayamon Puerto Rico

With concerns in energy crisis and global warming, researchers are actively investigating alternative energy renewable solutions. Among the various methods, piezoelectric transduction stands out due to its impressive electromechanical coupling factor and coefficient. As a result, piezoelectric energy harvesting has garnered significant attention from the scientific community. In this study, we explored methods to enhance the piezoelectric properties of polyvinylidene fluoride (PVDF) through two distinct approaches. The first approach involved applying external high voltages at various stages during the mixture reaction. The goal was to determine whether this voltage application could alter or enhance PVDF’s piezoelectric conformation by improving the alignment of polarized dipoles. In the second part of our study, we investigated the effects of incorporating various nanostructures (including Iron oxide, Magnesium oxide, and Zinc oxide) into PVDF. To analyze changes in PVDF’s crystalline structure, we utilized Fourier Transform Infrared Spectroscopy (FTIr) and X-ray Diffraction (XrD) techniques. Additionally, we measured the electric polarization of samples using a Precision LC Meter and examined the morphology of nanofibers through Scanning Electron Microscopy (SEM).

关键词： Poly (Vinylidene Fluoride) (PVDF) Energy Harvesting Electrospinning Nanoparticles Zno Mgo Fe3o4

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A review on the scale-up of high-shear wet granulation processes and the impact of process parameters

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Particuology 2024年第9期92卷 180-195页

作者： Ana rita Alves Marta Filipe Simões Sérgio Simões João Gomes University of Coimbra CERESDepartment of Chemical EngineeringFaculty of Sciences and TechnologyRua Sílvio Lima3030-790CoimbraPortugal Bluepharma-Indústria Farmacêutica São Martinho do BispoCoimbra3045-016Portugal Faculty of Pharmacy University of CoimbraAzinhaga de Santa Comba3000-548CoimbraPortugal

Wet granulation is one of the most important agglomeration processes,and high-shear granulation(HSG)one of the most employed technologies in the pharmaceutical *** most critical process parameters of HSG are discussed in this *** main concern in scaling up the wet granulation process is the differences between scales,which prevent the particles from having the same experience across all *** scale-up of wet granulation processes is commonly divided into two categories:engineering and attribute-based *** engineering-based scale-up approach is a strategy based on dimensional analysis and an attribute-based supported on the principles of“equifinality”,where process variables are adjusted to obtain equivalent granule *** work presents the effect of different HSG process parameters on the scale-up,as well as the use of process analytical tools(PAT)and modelling *** aim is to review applied scale-up approaches in HSG and discuss benefits and *** is proven why the scale-up for oral solid pharmaceutical products is still considered a hot topic and a very challenging task for development and engineering teams.

关键词： High-shear wetgranulation Parametric-based Attribute-based Physics-based modelling Impeller design Scale-up

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Determination of critical state line(CSL)for silty-sandy iron ore tailings subjected to low-high confining pressures

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Journal of rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1684-1695页

作者： Nilo Cesar Consoli João Vítor de Azambuja Carvalho Alexia Cindy Wagner Hugo Carlos Scheuermann Filho Inácio Carvalho Pedro Pazzoto Cacciari João Paulo de Sousa Silva Civil Engineering Universidade Federal do Rio Grande do SulPorto AlegreRS90035-190Brazil Exploration and Mineral Projects-Mineral Development Centre VALE S.A.Santa LuziaMG33040-900Brazil Department of Civil Geological and Mining EngineeringPolytechnique MontrealQuebecH3C 3A7Canada

The disposal of filtered tailings in high dry stacks can induce particle breakage,changing the material's behaviour during the structure's *** grading changes influence material properties at the critical state,and this is not mature for intermediate artificial soils(tailings)in a broad range of confining *** this paper,it aims to describe the behaviour of iron ore tailings in a spectrum of confining pressures broader than the reported in previous studies.A series of consolidated drained(CD)triaxial tests was carried out with confining pressures ranging from 0.075 MPa to 120 *** results show that the amount of breakage plays an essential role in the response of iron ore *** existence of curved critical state line(CSL)in both specific volume(ν)-logarithm of mean effective stress(p′)and deviatoric stress(q)-mean effective stress(p′)planes,and different responses in the deviatoric stress-axial strain-volumetric strain curves were *** inverse S-shaped equation was proposed to represent the silty-sandy tailings'behaviour up to high pressures onν-lnp′*** proposed equation provides a basis for enhancing constitutive models and considers the evolution of the grading up to severe loading *** adjustment considered three regions with different responses associated with particle breakage at different pressure levels.

关键词： Tailings Iron ore tailings dry stacking Silty-sandy material Critical state soil mechanics High confining pressures Particle breakage

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