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Influence of curing conditions on the shrinkage behavior of three-dimensional printed concrete formwork

Frontiers of Structural and Civil Engineering 2024年第8期18卷 1225-1236页

作者： m.bEKAERT K.van TITTELbOOm G.de SCHUTTER magnel-Vandepitte Laboratory for structural Engineering and building materials Department of Structural Engineering and Building MaterialsFaculty of Engineering and ArchitectureGhent UniversityGhent 60 B-9052Belgium

The use of three-dimensional(3D)printed concrete as formwork is becoming more widely applied within the ***,the technology is still not optimized and there are many reports of preliminary cracking during the curing of cast *** is believed to result from differential shrinkage between the printed and cast *** cracks(in the printed concrete or at the interface between the infill and printed concrete)form a preferential path for aggressive substances and can reduce the durability of the combined concrete *** ensure the desired service life of the structure,it is important that the differential shrinkage between cast and printed concrete is *** study investigated the effect of curing conditions on the differential shrinkage behavior of 3D and cast *** influence of prewetting of the dry-cured 3D printed formwork was also *** the experimental program,a vibrated and self-compacting concrete were used as cast *** 3D printed formwork was produced and combined with cast concrete to simulate a concrete *** formwork was cured for 1,7,or 28 d exposed to the air(relative humidity:60%or 95%)or submerged in *** length change of the combined elements was observed over 56 d after concrete casting and throughout the thickness of the *** show that increasing the curing period in dry conditions of the printed concrete leads to an expansion of the formwork on the first day after *** expansion leads to a non-uniform strain evolution throughout the curing period of the combined *** concrete formwork stored in wet conditions does not expand after the casting process but tends to show a decreasing linear deformation within the whole elements.

关键词： 3D concrete printing formwork shrinkage curing

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Selection criteria of mPOb-Angola germplasm collection for yield improvement of the oil palm

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Oil Crop Science 2024年第1期9卷 20-28页

作者： A.Norziha Z.Zamri Y.Zulkifli A.m.Fadila m.marhalil malaysian Palm Oil board 6Persiaran InstitusiBandar BaruBangi43000KajangSelangorMalaysia Institute of System biology Universiti Kebangsaan Malaysia43600BangiSelangorMalaysia

Oil palm germplasm collected from Angola,Africa in 1991 were subjected to genetic variability potential *** collection was planted in the form of open-pollinated families as trials at the malaysian Palm Oil board(mPOb)Kluang Research Station,Johor,malaysia,in *** palms from 52 families and tenera palms from 44 families of mPOb-Angola were evaluated for their bunch yield and bunch quality *** objectives of this study were to determine the genetic variability among the families and performance of mPOb-Angola germplasm for yield *** analysis of variance(ANOVA)revealed highly significant differences between the dura and tenera families for most of the traits,suggesting the presence of high genetic variability,which is essential for breeding *** the duras,family AGO 02.02 displayed the best yield performance,with a high fresh fruit bunch,oil yield and total economic product at 240.40,29.46 and 37.93 kg palm^(-1)year^(-1),*** for the teneras,family AGO 03.04 recorded the highest FFb yield and oil yield at 249.25 and 45.22 kg palm^(-1)year^(-1),*** that,several families with big fruit sizes or producing a mean fruit weight of 14-17 g were also *** dura and tenera from AGO 01.01 recorded the highest oil to bunch(O/b)of 17.76%and 28.65%,*** findings will facilitate the selection of palms from the mPOb-Angola germplasm for future breeding programmes.

关键词： Oil palm Germplasm Genetic variability Heritability Yield improvement

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Vanadium mineralization at Los Chihuidos sediment-hosted Cu-V deposit,Neuquén basin,Argentina:An approach to vanadium ore forming processes

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Geoscience Frontiers 2024年第1期15卷 225-246页

作者： Ana L.Rainoldi Daniel beaufort marta b.Franchini Adolfo Giusiano Sabine Petit Patricia Patrier m.Josefina Pons Dpto.de Geología Universidad Nacional del Sur(UNS)8000 Bahía BlancaArgentina Consejo Nacional de Investigaciones Científicas y Técnicas Centro Patagónico de Estudios MetalogenéticosArgentina Universitéde Poitiers IC2MPCNRS-UMR 7285HydrasaF-86022 Poitiers CedexFrance Universidad Nacional del Comahue Facultad de IngenieríaDepartamento de Geología y Petróleo8300 NeuquénArgentina Consultant Geologist 8300 NeuquénArgentina Universidad Nacional de Río Negro Instituto de Investigación en Paleobiología y GeologíaRío NegroArgentina

Vanadium mineralization at Los Chihuidos deposit of the Neuquén basin is linked to the development of a redox front system related to the inflow of hydrocarbons into the red sandstone of the Huincul *** of hydrocarbons with oxidized red beds and connate water generated redox reactions where hematite was dissolved due to iron reduction resulting in the discoloration of the red *** the contact between oxidized red sandstone and reduced white sandstone,precipitation of specific mineral phases resulted in the V ore with minor amounts of *** the implementation of the redox interface,abundant V-montmorillonite and V-hematite precipitated at the more oxidizing conditions and Cu-V-corrensite-type at the more reducing conditions of the redox *** the redox front advanced with fluids constantly migrating into the reservoir,more reducing conditions were stablished,promoting chloritization and minor illitization with V-Cu incorporation and continuous upgrading of the *** ore mineralogy consists of clay minerals including V-bearing montmorillonite,Cu-V-corrensite-type,V-di-trioctahedral chlorite and Cu-tri-trioctahedral chlorite with minor V-illite-smectite mixed-layer minerals and associated secondary *** over illitization was favored due to high amounts of Fe and mg in detrital clasts and in connate fluids and by low K availability related to low amounts of detrital *** spatial transition of V and/or Cu bearing clay minerals observed through the mineralized redox front at Los Chihuidos deposit(kaolinite→smectite→illite/smectite→corrensite-type→di-trioctahedral-chlorite→tri-trioctahedral-chlorite)and the related variation of V-Cu concentrations in bulk rock are indicative of increasing pH and decreasing Eh of resident solutions from red to white sandstones during the hypogene mineralization *** influx of Cu-rich oxidized basinal brines precipitated main copper ore with Cu-sulfides in the white sandst

关键词： Clay minerals V-chlorite Redox front bleaching Hydrocarbons

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Organic petrographic and mineralogical composition of the No. 6 coal seam of the Soutpansberg Coalfield, South Africa: Insights into paleovegetation and depositional environment

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International Journal of Coal Science & Technology 2024年第3期11卷 190-207页

作者： Sanki biswas Nicola J.Wagner Ofentse m.moroeng DSI-NRF CImERA/PPm Research Group Department of GeologyUniversity of JohannesburgJohannesburgSouth Africa

This study investigates the paleodepositional conditions of the No.6 Seam of the madzaringwe Formation in makhado and Voorburg south area of the Soutpansberg Coalfield(Limpopo Province,South Africa)utilizing organic petrography and inorganic geochemical *** coals are predominantly high-volatile bituminous b-A rank with high ash yields(avg.36.1 wt%),characterized by high-vitrinite(~41.5 vol%),moderate-to-high inertinite(9.8 vol%–33.7 vol%)and low liptinite(~2.3 vol%).The distribution of inertinite varies among different coal horizons(from bottom-lower to middle-upper),suggesting differential oxidation conditions and/or paleofire ***-to-inertinite(V/I)ratio,tissue preservation–gelification index(TPI–GI),and groundwater–vegetation index(GWI–VI)plots,indicate that the peat-forming forest-swamp vegetation accumulated under mesotrophic-to-rheotrophic hydrological *** presence of structured macerals(i.e.,telinite,collotelinite,fusinite,and semifusinite)suggests well-preserved plant tissues,whereas framboidal pyrite and sulphur content(0.24 wt%–2.16 wt%)point to brackish-water influence at the peat *** coals contain quartz,kaolinite,siderite,muscovite,dolomite,calcite,and pyrite minerals,most of which were likely sourced from felsic igneous *** Al/(Al+Fe+mn)and(Fe+mn)/Ti ratios for the studied samples range between 0.24–0.97 and 0.57–70.10,*** ratios,Al–Fe–mn plot,and presence of massive botryoidal-type pyrite imply some influence of meteoric waters or fluids from hydrothermal activity ***,the chemical index of alteration(CIA:98.25–99.67),chemical index of weathering(CIW:92.04–97.66),and A–CN–K ternary diagram suggest inorganic matter suffered strong chemical weathering,indicating warm paleoclimatic conditions during the coal formation.

关键词： macerals Coal facies Geochemical-indices Hydrothermal madzaringwe formation Soutpansberg Coalfield

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A combined tectono-climatic control on Holocene sedimentation in Ladakh Himalaya,India: Clues from Anisotropy of magnetic Susceptibility(AmS) of lake sediments

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Journal of Palaeogeography 2024年第4期13卷 738-753页

作者： b.V.Lakshmi K.Deenadayalan md.mujahed baba Saumitra misra Indian Institute of Geomagnetism Discipline of Geological Sciences SAEESUniversity of Kwa Zulu-Natal

Anisotropy of magnetic Susceptibility(AmS) data from a ～27.8 m thick soft sedimentary mud sequence(～10.5-3.25 k yrs) from the Spituk Palaeolake Sequence(SPSS) of Holocene age, located in the northern bank of the Indus River in the Leh-Ladakh Himalaya, show effects of tectonic versus climate dynamics responsible for the Himalayan sedimentation. The sedimentary sequence, consisting of alternating of aeolian sand and glacio-fluvial mud flow deposits, has been subdivided into an older Last Glacier Phase I(LGP 1) and a younger Last Glacier Phase II(LGP 2), where the termination of each phase is marked by the occurrence of gravel beds of thickness ≤1 m, which were deposited due to glacial melting. The present AmS data along with previously published information on sedimentology confirm that the mudflow deposits of the LGP 1 and LGP 2phases were deposited in a lacustrine environment under glacio-fluvial conditions. However, a weak fluvial flow towards NW and NE could have existed for the LGP 1 and LGP 2, respectively. The glacial beds terminating LGP 1 and LGP 2 appear to have formed by climatic warming and tectonic activity, respectively. Hence, the Holocene Himalayan sedimentation was influenced by both climatic and tectonic activities. However, the thickness of the gravel bed(～0.8 m) terminating LGP 2 occupies only ～ 2.8 vol % of the total studied thickness～28 m, of the SPSS in the present study, which indicated a lesser control of tectonism in the growth of the Himalaya in and around the study area.

关键词： Holocene palaeolake sequence AmS studies Gravel beds Deglaciation Tectonic instability

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Correcting distortions of thin-walled machined parts by machine hammer peening

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Chinese Journal of Aeronautics 2024年第6期37卷 439-453页

作者： Aitor mADARIAGA mikel CUESTA Gorka ORTIZ-DE-ZARATE Eneko SAENZ-DE-ARGANDONA Denis SORIANO michael b.PRImE Pedro Jose ARRAZOLA Department of materials University of ManchesterOxford RoadManchester M139PLUnited Kingdom mechanical and Industrial Production Department Faculty of EngineeringMondragon UnibertsitateaArrasate 20500Spain Los Alamos National Laboratory Los AlamosNew MexicoUSA

Thin-walled aerostructural components frequently get distorted after the machining *** to correct distortions or eventually rejecting parts significantly increases the *** paper proposes a new approach to correct distortions in thin-walled components by strategically applying hammer peening on target surfaces of a machined *** alloy 7475-T7351 was chosen for this *** study was divided in two ***,the residual stresses(RS)induced by four different pneumatic hammer peening conditions(modifying the stepover distance and initial offset)were characterised in a test coupon,and one of the conditions was selected for the next *** the second stage,a FEm model was used to predict distortions caused by machining in a representative ***,the RS induced by hammer peening were included in an FEm model to define two hammer peening strategies(varying the coverage area)to analyse the capability to reduce *** workpieces were machined and then treated with the simulated hammer peening strategies for experimental *** in the test coupon showed that pneumatic hammer peening can generate high compressive RS(-50 to350 mPa)up to 800 lm depth,with their magnitude increasing with a reduced stepover *** of hammer peening over 4% of the surface of the representative workpiece reduced the machininginduced distortions by 37%,and a coverage area of 100% led to and overcorrection by a factor of *** confirms that hammer peening can be strategically applied(in target areas and changing the percentage of coverage)to correct low or severe distortions.

关键词： Aeronautics machining,Hammer Peening Aluminium alloy Distortions Residual Stress

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Impact on Soil Organic C and Total Soil N from Cool- and Warm-Season Legumes Used in a Green manure-Forage Cropping System

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Agricultural Sciences 2024年第3期15卷 333-357页

作者： Clark b. Neely Francis m. Rouquette Jr. Cristine L.S. morgan Frank m. Hons William L. Rooney Gerald R. Smith Department of Soil and Crop Science Washington State University Pullman WA USA Texas A&m AgriLife Research Overton TX USA Chief Scientific Officer Soil Health Institute Morrisville NC USA Department of Soil and Crop Science Texas A&M University College Station TX USA

Annual forage legumes are important components of livestock production systems in East Texas and the southeastern US. Forage legumes contribute nitrogen (N) to cropping systems through biological N fixation, and their seasonal biomass production can be managed to complement forage grasses. Our research objectives were to evaluate both warm- and cool-season annual forage legumes as green manure for biomass, N content, ability to enhance soil organic carbon (SOC) and soil N, and impact on post season forage grass crops. Nine warm-season forage legumes (WSL) were spring planted and incorporated as green manure in the fall. Forage rye (Secale cereale L.) was planted following the incorporation of WSL treatments. Eight cool-season forage legumes (CSL) were fall planted in previously fallow plots and incorporated as green manure in late spring. Sorghum-sudangrass (Sorghum bicolor x Sorghum bicolor var. sudanense) was planted over all treatments in early summer after forage rye harvest and incorporation of CSL treatments. Sorghum-sudangrass was harvested in June, August and September, and treatments were evaluated for dry matter and N concentration. Soil cores were taken from each plot, split into depths of 0 to 15, 15 to 30 and 30 to 60 cm, and soil C and N were measured using combustion analysis. Nylon mesh bags containing plant samples were buried at 15 cm and used to evaluate decomposition rate of above ground legume biomass, including change in C and N concentrations. mungbean (Vigna radiata L. [Wilczek]) had the highest shoot biomass yield (6.24 t Dm ha-1) and contributed the most total N (167 kg∙ha-1) and total C (3043 kg∙ha-1) of the WSL tested. Decomposition rate of WSL biomass was rapid in the first 10 weeks and very slow afterward. Winter pea (Pisum sativum L. spp. sativum), arrow leaf clover (Trifolium vesiculosum Savi.), and crimson clover (Trifolium incarnatum L.) were the most productive CSL in this trial. Austrian winter pea

关键词： Annual Legumes Soil N Soil Organic C Green manure Deer browse Forage Cropping Systems

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biochemical Liver Functions and molecular Identification of Fasciola hepatica from Experimentally Infected Rat model

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Open Journal of Animal Sciences 2024年第2期14卷 88-100页

作者： Omnia m. Kandil Emad b. Ata margarita P. Gabrashanska Hatem A. Shalaby Tamer H. Abd El-Aziz Noha m. F. Hassan Soad m. Nasr mohamed A. Helal Ebtesam m. Al-Olayan Department of Parasitology & Animal Diseases Veterinary Research Institute National Research Centre Giza Egypt Institute of Experimental morphology Pathology and Anthropology with Museum Bulgarian Academy of Sciences Sofia Bulgaria Department of Zoology Collage of Science King Saud University Riyadh Saudi Arabia

The current study was performed to evaluate the liver function status as well as molecular characterization of the recovered worms in rats experimentally infected with F. hepatica. Sixteen male Wister rats aged 30 days were randomly allocated into two groups (n = 8). The first group was infected orally with 15 viable encysted metacercaria of F. hepatica per animal. The other group was kept non-infected (control group). At zero time (before infection), the 2nd, 4th, 6th, 8th, 10th, 12th and 14th weeks post-infection (WPI), blood and serum samples were collected via puncture of retro-orbital plexus of veins from each rat. Serum enzyme level (AST and ALT) and total protein were measured, and the serum protein profile was carried out using agarose gel electrophoresis. During the period of the experiment, serum ALT and AST activities and serum total globulins significantly increased while serum total proteins and albumin markedly decreased in the infected group. On the 14th WPI, the data of the electropherogram showed that globulin fractions (α1-, β- and γ-globulin) levels were significantly increased while α2-globulin was markedly decreased in the infected group. The molecular analysis confirmed the amplification of the ITS1, ITS2 and NDI genes of F. hepatica recovered from the infected liver of rats with amplicon sizes of 630, 510 and 560 bp, respectively. Sequencing of the amplified ITS gene resulted in the determination of 3 strains (PP108836, PP108837, and PP108838). Also, analysis of the ITS2 gene resulted in obtaining 3 isolates under the accession numbers (PP109065, PP109066, and PP109067). In conclusion, fasciolosis in the rat model is suitable for routine experimental infections and caused a pronounced liver dysfunction with discharging of the Fasciola eggs in the faeces and the development of adult stages in the bile ducts. Furthermore, molecular techniques are a sensitive

关键词： Fasciola hepatica Liver Functions Serum Enzymes Serum Protein Electrophoresis molecular Characterization

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Subnormal Serum Liver Enzyme Levels:A Review of Pathophysiology and Clinical Significance

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Journal of Clinical and Translational Hepatology 2024年第4期12卷 428-435页

作者： Elham m.Youssef George Y.Wu biochemistry Department National Research CenterCairoEgypt Department of medicine Division of Gastroenterology-HepatologyUniversity of Connecticut Health CenterFarmingtonCTUSA

Subnormal levels of liver enzymes,below the lower limit of normal on local laboratory reports,can be useful *** instance,subnormal levels of aminotransferases can be observed in vitamin b6 deficiency and chronic kidney *** alkaline phosphatase levels may indicate the presence of hypophosphatasia,Wilson's disease,deficiencies of divalent ions,or *** levels of gamma glutamyl transferase may be seen in cases of acute intrahepatic cholestasis,the use of certain medications,and in bone ***,subnormal levels of 5'-nucleotidase have been reported in lead poisoning and nonspherocytic hemolytic *** aim of this review is to bring attention to the fact that subnormal levels of these enzymes should not be ignored as they may indicate pathological conditions and provide a means of early diagnosis.

关键词： Transaminases Vitamin b6 Celiac disease Renal insufficiency Hepatolenticular Degeneration Crohn disease malnutrition Clofibrate bone diseases Lead poisoning Anemia Hemolytic

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Fluoride contamination in groundwater:A global review of the status,processes,challenges,and remedial measures

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Geoscience Frontiers 2024年第2期15卷 1-29页

作者： E.Shaji K.V.Sarath m.Santosh P.K.Krishnaprasad b.K.Arya manisha S.babu Department of Geology University of KeralaKariavattom CampusThiruvananthapuramKerala 695581India School of Earth Sciences and Resources China University of Geosciences(Beijing)29 Xueyuan RoadBeijing 100083China Department of Earth Science University of AdelaideAdelaideSA 5005Australia Department of Geology Central University of KeralaTejaswini HillsPeriyeKasaragodKerala 671316India

Groundwater pollution by fluoride is one of the prime concerns of the world population due to its toxicity,which results in adverse health *** this paper,we review the current scenario of the fluoride contamination of groundwater in various countries across the globe and its impact on human *** the last decade,several newly affected regions have been reported all over the world,with more than 100 countries affected by fluoride contamination in groundwater(concentration exceeding the acceptable limit of 1.5 mg/L defined by the World Health Organization).Fluoride poisoning is mainly due to the unsupervised ingestion of products for dental and oral hygiene and over-fluoridated drinking *** is estimated that more than 200 million people from different countries are affected by fluoriderelated groundwater issues and health *** highest among these are from the countries in Africa(38),Asia(28),and Europe(24),followed by countries like South America(5),North America(3),and Australia(2).The source of fluoride in drinking water is primarily geogenic,together with forage,grasses and grains,tea,and anthropogenic *** countries affected were correlated with climatic zones and geological factors to gain insights into geospatial *** analyses show that most of the fluoride pollution-prone zones are located in high-grade metamorphic terranes with granitoid or alkaline intrusions,geothermal hot springs,and volcanic regions with arid or semi-arid climatic *** study also finds that children across the globe are more vulnerable than adults to fluoride *** review finds that,although there are efficient fluoride removal techniques,including filters with next-generation nanomaterials,to date,there has not been a single technique developed that can claim to be a practically robust solution for fluoride removal from drinking ***,we suggest developing next-generation filters that can retain essential miner

关键词： Fluoride Groundwater Water contamination WHO standards Climate zones Remediation Sustainable Development Goals

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