Quantitative study on the changes of Karst groundwater level and hydrochemistry in Jinci spring catchment, Shanxi, China

Since Jinci spring ceased to flow on April 30, 1994, it has never been reflowed, which seriously affects the sustainable utilization of karst groundwater. The purpose of this paper is to provide the basis for the reflow of Jinci spring and the sustainable protection for karst groundwater. Based on the long-term monitoring data from 1994 to 2014, this paper accurately quantifies the changes in the quantity and hydrochemistry of karst groundwater resources. By means of the Mann–Kendall trend test method, this paper analyzes the variation trends of karst groundwater level, EC, and SO42− in Jinci spring catchment. Monitoring data show that the groundwater level in the karst aquifer declined by 2.32 m from 1994 to 2008, which is equivalent to a loss of 3.3 Mm3 in aquifer storage, while the groundwater level rose by 17.67 m from 2009 to 2014, which constitutes a gain of 25.2 Mm3. The results indicate that (1) karst groundwater level showed a rising trend, which was mainly controlled by the rainfall, exploitation of karst groundwater, and the Fenhe River leakage; (2) groundwater salinity varied greatly and showed an increasing trend: increasing order of 47.83% for the six major ions, 37.52% for EC, and 3.34% for pH; (3) the increase of groundwater salinity is governed by the increase in rainfall salinity, the increase in groundwater runoff time, the recharge of the Fenhe River to groundwater, the increase of sewage in spring catchment, and the ease of solubility of carbonate rocks. The results of this study are of great significance for predicting the groundwater level and salinity of karst aquifer and ensuring the safety of drinking water in Jinci spring catchmen

Quadrupole and octupole collectivity in the semi-magic nucleus 80206Hg126

The first low-energy Coulomb-excitation measurement of the radioactive, semi-magic, two proton-hole nucleus 206Hg, was performed at CERN's recently-commissioned HIE-ISOLDE facility. Two γ rays depopulating low-lying states in 206Hg were observed. From the data, a reduced transition strength B(E2;21+→01+)=4.4(6) W.u. was determined, the first such value for an N=126 nucleus south of 208Pb, which is found to be slightly lower than that predicted by shell-model calculations. In addition, a collective octupole state was identified at an excitation energy of 2705 keV, for which a reduced B(E3) transition probability of 30−13+10 W.u. was extracted. These results are crucial for understanding both quadrupole and octupole collectivity in the vicinity of the heaviest doubly-magic nucleus 208Pb, and for benchmarking a number of theoretical approaches in this key region. This is of particular importance given the paucity of data on transition strengths in this region, which could be used, in principle, to test calculations relevant to the astrophysical r-process

Dissipative Capacity Analysis of Steel Buildings using Viscous Bracing Device

Abstract — Energy dissipation Systems in civil engineering structures are sought when it comes to removing unwanted energy such as instability, earthquake and wind. Among these systems, there is the combination of structural steel frames with passive energy dissipation provided by Fluid Viscous Dampers (FVD). This device is increasingly used to provide better seismic protection for existing as well as new buildings and bridges. A 3 D numerical investigation is done considering the seismic response of a twelve-story steel building moment frame with diagonal FVD that have linear force versus velocity behaviour. Nonlinear time history, which is being calculated by Fast nonlinear analysis (FNA), of Boumerdes earthquake (Algeria, May 2003) is considered for the analysis and carried out using the SAP2000 software and comparisons between unbraced, braced and damped structure are shown in a tabulated and graphical format. The results of the various systems are studied to compare the structural response with and without this device of the energy dissipation thus obtained were discussed. The conclusions showed the formidable potential of the FVD to improve the dissipative capacities of the structure without increasing its rigidity. It is contributing significantly to reduce the quantity of steel necessary for its general stability

Influence of Fluorine on Clinker burnability and mechanical properties of CPA Moroccan cement

It has been found that the addition of certain components, despite their low concentration in raw mix, may accelerate and enhance the reactivity of the cement raw mix. The utilization of mineralizers to facilitate and quicken the process of clinkerization backpedals numerous years, the concept of using such mineralizers to burn normal raw mixes at a much lower temperature with the end goal of decreasing the fuel necessities of the furnace and to enhance the cement proprieties has become to be seriously considered over the most recent couple of years. The subject of this paper is to investigate the impact of calcium fluoride as mineralizer on addition during the clinkerization process of industrial raw mixtures and its effect on chemical, mineralogical, and mechanical properties of CPA Moroccan cement. Five different raw meals were utilized and were burned with 2% of calcium fluoride. The resulting clinker was analyzed by X-ray diffraction (XRD) and fluorescence spectroscopy to determine the chemical phases of the obtained clinker, and the mechanical properties of resulting CPA cement were determined. The results show that the addition of 2% of CaF2 to the clinker raw meal induced a decrease in the burning temperature and free lime, while improving the clinker phase formation and the mechanical properties of obtained cement

Influence of Fluorine on Clinker burnability and mechanical properties of CPA Moroccan cement

It has been found that the addition of certain components, despite their low concentration in raw mix, may accelerate and enhance the reactivity of the cement raw mix. The utilization of mineralizers to facilitate and quicken the process of clinkerization backpedals numerous years, the concept of using such mineralizers to burn normal raw mixes at a much lower temperature with the end goal of decreasing the fuel necessities of the furnace and to enhance the cement proprieties has become to be seriously considered over the most recent couple of years. The subject of this paper is to investigate the impact of calcium fluoride as mineralizer on addition during the clinkerization process of industrial raw mixtures and its effect on chemical, mineralogical, and mechanical properties of CPA Moroccan cement. Five different raw meals were utilized and were burned with 2% of calcium fluoride. The resulting clinker was analyzed by X-ray diffraction (XRD) and fluorescence spectroscopy to determine the chemical phases of the obtained clinker, and the mechanical properties of resulting CPA cement were determined. The results show that the addition of 2% of CaF2 to the clinker raw meal induced a decrease in the burning temperature and free lime, while improving the clinker phase formation and the mechanical properties of obtained cement

Structure et interactions magnétiques de composés polymétalliques de basse dimensionnalité

Le 2,5 - Bis (pyridin - 2 yl) - 1, 3, 4 - oxadiazole (b.p.o.) est un ligand capable de coordiner un ou plusieurs atomes de Cu(II) selon les conditions expérimentales. La complexation par CuCl2 conduit à la cristallisation d’espèces mononucléaires même en présence d’un large excès de Cu (II). L’introduction dans le milieu réactionnel d’un chlorure de métal bivalent, tel que Ni, Co, Mn, entraîne la formation d’un complexe cuivrique polymétallique cristallisant en chaîne unidimensionnelle. Les structures cristallines ont été résolues par diffraction des rayons X. Le comportement paramagnétique de la chaîne montre qu’il n’y a pas de couplage entre les atomes de Cu(II

Rapport : phase diagnostic / Projet systèmes pastoraux en steppe maghrébine; zone El Gueddid W. Djelfa, Algérie

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Mechanical performance of cement mortar with olive pomace aggregates and olive mill wastewater: an experimental investigation

AbstractThis study investigates the potential use of olive aggregates (OA) in the production of cementitious materials as a substitute for natural sand to reduce excessive use of this resource. Two types of OA were used: OPA (olive pomace aggregates) and OPMW (OPA mixed with olive mill wastewater). The aim was to determine experimentally whether improvements in the mechanical properties of the produced lightened cement mortar could be obtained compared to the reference mortar. Laboratory tests were conducted on two series of mortar samples made by replacing 0%, 5%, 10%, and 15% of natural sand with both dry and saturated OA. The best results were observed in a mixture containing 5% of OPMW at the dry state, which had a marginal effect on the compressive strength of the produced mortar, reaching 33.50 MPa after 28 days of curing. However, microstructural analysis revealed low adhesion between the OA and the cement matrix at the interface transition zone (ITZ) after 28 days. Increasing the OA content was found to decrease the workability of the mixture while also increasing the porosity of the resulting lightened cement mortar. Additionally, the use of OA reduces ultrasonic pulse velocity and dynamic modulus of elasticity. Overall, the best results were obtained with the mixture containing 5% of OPMW at the dry state, which meets the standards for general use of building materials

Composting parameters and compost quality: a literature review

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