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Use and application of cFc-11,cFc-12,cFc-113 and SF6 as environmental tracers of groundwater residence time:A review

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Geoscience Frontiers 2019年第5期10卷 1643-1652页

作者： l.A. chambers d.c. Gooddy A.M. Binley department of civil and Environmental Engineering University of StrathclydeGlasgowG1 1XJUK lancaster Environment centre Lancaster UniversityLancasterLA1 4YQUK British Geological Survey Maclean BuildingWallingfordOX10 8BBUK

Groundwater residence time is a fundamental property of groundwater to understand important hydrogeological issues,such as deriving sustainable abstraction volumes,or,the evolution of groundwater *** anthropogenic trace gases chlorofluorocarbons (cFc-11,cFc-12 and cFc-113) and sulphur hexafluoride (SF6) are ideal in this regard because they have been released globally at known rates and become dissolved in groundwater following Henry’s law,integrating over large spatial (global) and temporal (decades) *** cFcs and SF6 are able to date groundwater up to w100 years old with the caveat of certain simplifying ***,the inversion of environmental tracer concentrations (cFcs and SF6) to derive groundwater age rests on the accurate determination of groundwater recharge parameters,namely temperature,elevation,salinity and excess air,in addition to resolving the potential for contamination,degradation and unsaturated zone *** review explores the fundamentals of cFc-11,cFc-12,cFc-113 and SF6 as environmental tracers of groundwater age and recommends complementary techniques *** this relatively simple and inexpensive technique has been used to determine initial concentrations at the recharge zone,setting the groundwater dating ‘clock’ to zero,this review then explores the meaning of groundwater ‘age’ in relation to measured environmental tracer *** is shown that the cFcs and SF6 may be applied to a wide-range of hydrogeological problems and suggests that environmental tracers are particularly powerful tools when integrated with numerical flow and transport models.

关键词： Hydrogeology Environmental tracers Groundwater dating

luminescence properties of dysprosium doped YVO_4 phosphor

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Journal of Rare Earths 2018年第12期36卷 1245-1249页

作者： H.J.Rajendra c.PANdurangappa d.l.Monika department of Physics RNS Institute of TechnologyChannasandra department of Physics SJB Institute of Technology

Trivalent dysprosium(dy) activated nanocrystalline yttrium vanadate(YVO) phosphor was synthesized via co-precipitation method. The prepared samples were characterized by X-ray diffraction(XRd),Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), optical absorption and photo luminescence(Pl) techniques. The XRd patterns reveal the tetragonal crystalline phase. SEM images reveal that dy doped YVOnanocrystals are agglomerated. EdAX confirms the formation of YVO:dy. FTIR spectrum shows two strong absorption bands at 459 and 761 cm. Optical absorption spectrum showed the surface defects in the as-prepared samples. The Pl emission spectrum shows two characteristic emission bands at 485 and 575 nm. The strong yellow emission peak at 575 nm is assigned to ~4 F→~6 Hhyper sensitive transition of dyions, Study of cIE chromaticity diagram indicates the suitability of the phosphor for the development of yellow-green lEds.

关键词： Precipitation Yttrium vanadate dysprosium X-ray diffraction Photoluminescence Rare earths

New insights into the hardening and pitting corrosion mechanisms of thermally aged duplex stainless steel at 475℃:A comparative study between 2205 and 2101 steels

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Journal of Materials Science & Technology 2022年第3期98卷 123-135页

作者： R.Silva G.S.Vacchi c.l.Kugelmeier I.G.R.Santos A.A.Mendes Filho d.c.c.Magalhães c.R.M.Afonso V.l.Sordi c.A.d.Rovere Munir Rachid corrosion laboratory Department of Materials EngineeringFederal University of São CarlosRodovia Washington Luis Km 23513565-905 São CarlosSPBrazil Engineering Modeling and Applied Social Sciences Center(CECS)Federal University of ABCAvenida dos Estados 500109210580 Santo AndréSPBrazil Federal University of São carlos Graduate Program in Materials Science and EngineeringBrazil

In this study,the relationship between spinodal decomposition and the formation of Ni-rich clusters and G-phase in the ferrite on hardening and pitting corrosion of two thermally aged duplex stainless steels(dSSs)at 475℃was *** indicate that,for 2205 dSS,pitting corrosion behavior is influenced by the presence and size of G-phase precipitates for longer aging times,but this contribution is masked by the advanced stage of spinodal decomposition in the ferritic *** the other hand,for 2101 dSS,the formation of cr-richer nitrides impairs pitting corrosion resistance more than spinodal decomposition.

关键词： duplex stainless steel Spinodal decomposition G-phase precipitation Pitting corrosion Hardening

The Use of Secondary Grape Biomass in Beef cattle Nutrition on carcass characteristics, Quality and Shelf life of Meat

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Food and Nutrition Sciences 2024年第6期15卷 447-469页

作者： Vitor l. Molosse Guilherme l. deolindo Rafael V. P. lago Bruna Klein claiton A. Zotti Marcelo Vedovato Marcylene V. da Silveira Priscila M. copetti Maria R. c. Schetinger Juscivete F. Favero Eliana l. Fiorentin Aleksandro S. da Silva Universidade do Estado de Santa catarina (UdESc) Chapec Brazil department of Animal Science UDESC Chapec Brazil department of Animal Science Universidade do Oeste de Santa Catarina Xanxere Brazil dean lee Research and Extension center Louisiana State University Alexandria LA USA department of Biochemistry Universidade Federal de Santa Maria Santa Maria Brazil department of Medicina Veterinria UNOCHAPEC Chapec Brasil

We determined whether the inclusion of 100 g/kg dry matter of grape pomace silage (GPS) and grape pomace bran (GPB) as substitutes for other traditional fiber sources in the diet of steers (charolais x Nellore) would improve carcass characteristics, meat quality and composition, and shelf life. Twenty-four animals (248 ± 19.32 kg of initial body weight) were fed a high concentrate diet for 121 days. carcass characteristics were measured, and the longissimus dorsi muscle was analyzed for fatty acid (FA) profile and composition. The meat was sl.c.d.and stored in air-permeable packages for 10 days. On each sampling day (d 1, 3, 7, and 10), oxidative stability, bacterial load, lipid and protein oxidation, and staining were analyzed. The experimental diets influenced the pH of cold carcasses only. The GPS group had a higher pH than the control. The GPS and GPB groups showed improved oxidant status (i.e., lower lipid peroxidation and concentrations of reactive oxygen species were in the meat of both groups than in control). On the first day of storage, the antioxidant enzyme glutathione S-transferase activity was more significant in the meat of the GPS and GPB groups than in the control. The bacterial loads in the meat were attenuated by GPS inclusion;there were lower total coliform counts and a trend toward lower counts for enterobacteria in the control group. The diets altered the FA profile of the meat;i.e., the GPB diet allowed for a more significant amount of the n-6 omegas in the meat, while the GPS diet showed a tendency for a more significant amount of n-6 and 9 omegas. Both diets (GPS and GPB) increased the amounts of long-chain FAs. The GPS diet decreased saturated FA levels. We conclude that the dietary treatments GPS and GPB are a promising alternative to maintain meat quality standards throughout in real-world retail conditions. These treatments gave rise to an improvement in the nutritional value of the meat due to the more significant amounts of FAs that im

关键词： Animal Nutrition Antioxidant Biomass Grape Meat Quality Microbiology Residue

Phenotypic nutrient up-take differences in an alley cropping system in semi-arid Machakos, Kenya

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Journal of Environmental Sciences 2001年第2期13卷 164-169页

作者： d.N. Mungai c.l.coulson c.J. Stigter J.K. Ng’ang’a d.N.Mugendi department of Geography University of NairobiNairdbiKenya department of Botany University of NairobiNairobiKenya department of Enviromnental Sciences Graduate School of Productian EcologyWageningen UniversityDuivendaal 26701 APThe Netherlands department of Meteorology University of NairobiNairobiKenya Kenya Forestry Research Instiute(KEFRI NairobiKanya)

Alley cropping of cassia siamea and maize was studied in semi arid Kenya for soil fertility improvement. Katumani composite maize was planted except in the short rains of 1988 (SR88) when a hybrid variety was sown. Therefore the grain yield per row increased differently in the alley cropped maize (cM). Sole maize (SM) and cM yields were higher in SR88 than in the long rains of 1988 (lR88) by 62% and 38%, while yields from the same treatments in lR89 were only 21% and 45% of those in SR88 These differences in relative maize yields are attributed to differences between the two maize varieties in competition under nutrient stress conditions.

关键词： alley cropping cassia siamea maize nutrients maize yield semi arid condition soil moisture Kenya

cysticercosis of the neck:a case report

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Asian Pacific Journal of Tropical Medicine 2010年第10期3卷 833-834页

作者： chandrakant Patil Rashmi Kharat(Patil) Prasad deshmukh Blenda d'souza department of E.N.T J.N.M.CSawangiWardhaMaharashtra

The neck is a rare site for *** few cases of cysticercosis presenting in the neck have been *** report one such case creating diagnostic dilemma.

关键词： cysticercosis Neck

Soil conditioning tests of clay for EPB tunnelling

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Underground Space 2022年第4期7卷 483-497页

作者： c.Todaro A.carigi l.Peila d.Martinelli d.Peila dIATI Polytechnic University of TurinItaly IGG CNRItaly

Tunnelling with earth pressure balance-tunnel boring machine(EPB-TBM)in clayey soil requires a careful conditioning to reduce the effect of clogging and *** the last decade,many researches have been carried out to understand how to reduce these negative behaviors using conditioning agents,and different laboratory test procedures have been proposed using both powdered clay and clay chips to quantify and assess the effect of conditioning in terms of reduction of clogging and *** this paper a review of the various proposed tests is ***,it can be seen that no unified assessment method on the soil conditioning is available and therefore the designers do not have consistent data on which their choices are *** present research proposes a laboratory test methodology to study clay conditioning taking both the behavior of chips and powdered clay into *** proposed procedure has been applied on two different clays,and the test results are presented and discussed to show how the proposed methodology could be applied.

关键词： Tunnel EPB-TBM Soil conditioning laboratory tests

Mechanical properties of gas hydrate-bearing sediments during hydrate dissociation

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Acta Mechanica Sinica 2018年第2期34卷 266-274页

作者： X.H.Zhang d.S.luo X.B.lu l.l.liu c.l.liu Institute of Mechanics Chinese Academy of SciencesBeijing 100190China college of Engineering University of Chinese Academy of SciencesBeijing 100049China Key laboratory of Gas Hydrate Ministry of Land and ResourcesQingdao 266071China Qingdao Institute of Marine Geology Qingdao 266071China

The changes in the mechanical properties of gas hydrate-bearing sediments(GHBS) induced by gas hydrate(GH) dissociation are essential to the evaluation of GH exploration and stratum instabilities. Previous studies present substantial mechanical data and constitutive models for GHBS at a given GH saturation under the non-dissociated condition. In this paper, GHBS was formed by the gas saturated method, GH was dissociated by depressurization until the GH saturation reached different dissociation degrees. The stress–strain curves were measured using triaxial tests at a same pore gas pressure and different confining pressures. The results show that the shear strength decreases progressively by 30%–90% of the initial value with GH dissociation, and the modulus decreases by 50% –75%. Simplified relationships for the modulus, cohesion, and internal friction angle with GH dissociated saturation were presented.

关键词： Gas hydrate-bearing sediments dissociation Mechanical properties Shear strength Triaxial test

Achieving superior strength-ductility synergy in a heterostructured magnesium alloy via low-temperature extrusion and low-temperature annealing

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Journal of Materials Science & Technology 2023年第32期163卷 32-44页

作者： H.Wang d.T.Zhang c.Qiu W.W.Zhang d.l.chen Guangdong Key laboratory for Advanced Metallic Materials Processing and Forming National Engineering Research Center of Near-net-shape Forming for Metallic MaterialsSouth China University of TechnologyGuangzhou 510640China department of Mechanical and Industrial Engineering Toronto Metropolitan University(formerly Ryerson University)350 Victoria StreetTorontoON M5B 2K3Canada

A low-alloyed Mg-1.2Zn-0.1ca(wt.%)alloy was fabricated via low-temperature extrusion and annealing at 250℃for different times(10,30,and 90 min)to attain heterostructures with different fine-grained fractions,focusing on the effect of heterostructure on the mechanical *** dynamic recrystallization(RX)occurred during extrusion at 150℃,and a lamellar structure consisting of fine RX grains and coarse unRX grains was *** subsequent annealing promoted static RX in the as-extruded alloy,leading to an increased fine-grained fraction from 67%to 95%.Meanwhile,the co-segregation of Zn and ca atoms impeded the migration of grain boundaries,thus achieving a fine grain size of 0.8–1.6μ*** sample annealed for 10 min with a fine-grained fraction of 73%and an average RX grain size of 0.9μm exhibited a superior combination of high yield strength(305 MPa)and good ductility(20%).In comparison,an excellent elongation of 30%was achieved in the alloy with a nearly fully-RXed microstructure and an average grain size of 1.6μm after 90 min annealing,despite a lower yield strength of 228 *** unRX grains,the hard orientation with(01–10)parallel to the extrusion direction and high-density dislocations made it more difficult to deform compared with the RX grains,thus producing hetero-deformation induced(HdI)*** fine grains and high-density dislocations,HdI strengthening is the key to achieving the superior mechanical properties of the low-alloyed Mg alloy.

关键词： low-alloyed magnesium alloy low-temperature extrusion Annealing Heterostructure Mechanical properties