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1.
57Fe Mössbauer spectroscopy has been used to characterize the iron-bearing minerals present in some British Columbia coals. The minerals observed in a range of samples include pyrite/marcasite, siderite, jarosite, rozenite or melanterite, and Fe2+ -bearing clay minerals such as illite. The presence of jarosite is confirmed through the magnetic hyperfine interaction observed at 4.2 K. The absence of magnetic ordering at 4.2 K for the ferrous sulphate component indicates the presence of rozenite, FeS04 · 4H20, or melanterite, FeS04 · 7H20, rather than szomolnokite, FeS04 · H20 or FeS04. The effects of ashing on two of the coals is also studied. 相似文献
2.
Garima Lakhanpal Jay R. Black Roser Casas-Mulet Meenakshi Arora Michael J. Stewardson 《河流研究与利用》2023,39(4):734-744
Fine particle clogging and faunal bioturbation are two key processes co-occurring in the hyporheic zone that potentially affect hyporheic exchange through modifications in the sediment structure of streambeds. Clogging results from excessive fine sediment infiltration and deposition in rivers, and it is known to decrease matrix porosity and potentially reduce permeability. Faunal bioturbation activity may compensate for the negative effect of clogging by reworking the sediment, increasing porosity, and preventing further infiltration of fines. Although both processes of clogging and bioturbation have received significant attention in the literature separately, their combined effects on streambed sediment structure are not well understood, mostly due to the lack of a standard methodology for their assessment. Here, we illustrate a novel methodology using X-ray computed tomography (CT), as proof of concept, to investigate how, together, clogging and bioturbation affect streambed porosity in a controlled flow-through flume. By visualising gallery formations of an upward conveyor macroinvertebrate; Lumbriculus variegatus as a model species, we quantified bioturbation activity in a clogged streambed, focusing on orientation, depth, and volume at downwelling and upwelling areas of the flume. Gallery creation increased the porosity of the streambed sediment, suggesting a potential improvement in permeability and a possible offset of clogging effects. We illustrate the promising use of X-ray CT as a tool to assess bioturbation in clogged streambeds, and the potential role of bioturbation activity supporting hyporheic exchange processes in streambeds, warranting further studies to understand the extent of bioturbation impacts in natural systems. 相似文献
3.
K. Rajakumari M.Vinoth Kumar Garima Verma S. Balu Dilip Kumar Sharma Sudhakar Sengan 《计算机系统科学与工程》2022,40(2):581-592
Cloud computing is an Information Technology deployment model established on virtualization. Task scheduling states the set of rules for task allocations to an exact virtual machine in the cloud computing environment. However, task scheduling challenges such as optimal task scheduling performance solutions, are addressed in cloud computing. First, the cloud computing performance due to task scheduling is improved by proposing a Dynamic Weighted Round-Robin algorithm. This recommended DWRR algorithm improves the task scheduling performance by considering resource competencies, task priorities, and length. Second, a heuristic algorithm called Hybrid Particle Swarm Parallel Ant Colony Optimization is proposed to solve the task execution delay problem in DWRR based task scheduling. In the end, a fuzzy logic system is designed for HPSPACO that expands task scheduling in the cloud environment. A fuzzy method is proposed for the inertia weight update of the PSO and pheromone trails update of the PACO. Thus, the proposed Fuzzy Hybrid Particle Swarm Parallel Ant Colony Optimization on cloud computing achieves improved task scheduling by minimizing the execution and waiting time, system throughput, and maximizing resource utilization. 相似文献
4.
5.
Microsystem Technologies - Watermarking is defined as about hiding any valuable information set in the particular digital media by itself through modifying the particular graphic contents. In our... 相似文献
6.
Measurements of the Hall coefficient and the d.c. conductivity were made on polycrystalline films prepared from mercury-rich HgTe. It was found that, in addition to grain boundary potential barrier scattering, the contribution of ionized impurity scattering is also quite significant. The effect of excess mercury in HgTe is to increase the mobility and to reduce compensating effects. 相似文献
7.
The idea of information improvement was introduced by Thiel [3]. This idea was further extended by the first author to information improvement due to 2 and N revisions and specifically states that different experimenters (a finite number) are required to proceed with given distributions P and U and are permitted to choose a suitable revision. We attempted to provide a measure of information corresponding to Theil's measure which reflected the effect of all revisions. In this paper, the authors have studied a joint characterization of information improvement of N revisions and its generalization by considering a suitable functional equation. 相似文献
8.
The present investigation reports the possibility of using Acacia saligna and Delbergia sisso pods to remove Cd(II) from aquatic systems in the form of calcium alginate modified immobilized composite beads (CAM-ASPCB and CAM-DSPCB). Batch and fixed bed column studies were carried out under various process affecting parameters. Maximum metal removal efficiency of 92% by CAM-ASPCB and 85% by CAM-DSPCB was observed under optimized conditions. Pseudo-second-order kinetic model, intra-particle diffusion, and Freundlich isotherm were found fitted well. The regeneration of the sorbents were found effectively high showing up to 10 cycles for simulated solution and up to 3 cycles for industrial effluent. 相似文献
9.
Silicon - In this article, a Heterogeneous Gate-Dielectric Nanosheet Tunnel Field Effect Transistor (HD-NSH-TFET) with three channels is investigated using the 3-D Visual TCAD simulator. The HD... 相似文献
10.
We consider a measure of the diversity of a population based on the λ-measure of hypoentropy introduced by Ferreri (1980).
Our purpose is to study its asymptotic distribution for testing hypotheses. A numerical example based on real data is given.
This work was partially supported by the Dirección General de Investigación Cientifica y Técnica (DGICYT) under the contract
PS89-0019. 相似文献