Stability pillar

THE ON-GOING PILLAR STABILITY EXPERIMENT AT THE ASPO HARD ROCK... 

Andersson, C. 2003. Aspo Pillar Stability Experiment. Feasibility Study. SKB, IPR-03-01. Swedish Nuclear Fuel and Waste Management Company, Stockholm. 

Rinne, M. Shen, B. Lee, H-S. 2003. Aspb Pillar Stability Experiment. Modelling of fracture stability by FRACOD. SKB, IPR-03-05. 

The Swedish Nuclear Fuel and Waste Management Company (SKB) is investigating the stability of a pillar between two closely located deposition holes at Aspo Hard Rock Laboratory (AHRL). This in-situ experiment is called Aspb Pillar Stability Experiment (APSE) and it is described more detailed elsewhere in this proceeding see APSE by Andersson et al. (2(X).1). 

Major objectives of the Aspo Pillar Stability Experiment are to demonstrate the capability to predict spalling in a fractured rock mass and to investigate the effect of the backfill (confining pressure) on the rock mass response. The FRACOD modelling aims to predict properly the fracturing process and the development of AE events during the planned sequences of excavation-confinement-heating. 

Rinne M, Shen B, Lee H-S, 2003. Aspo pillar stability experiment. Part I Modelling of fracture stability by FRACOD. Part II Modelling Fracture Initiation and Acoustic Emission. Part III Reconstruction of Stress Field Using an Inverse Technique. International Progress Report, IPR-03-05. Swedish Nuclear Fuel and Waste Management Company, Stockholm, 2003. 

Jia G.S. Kang L.J. 2002. Study on the Chain Pillar Stability of the Developing Entry in Long Wall Top-coal Min-ing. Journal of China Coal Society 27(l) 6-10(in Chinese). 

By considering the results of previous experiment, they synthesized cobalt-, nickel-, copper-, and zinc-based, new pillared MOFs of similar topologies which exhibited good water stability [233]. The grafted methyl group on the benzene dicarboxlate (BDC) ligand introduced steric factors around the metal centers consequently, water stability of MOF drastically improved. 

The basicity of BTTB-based MOFs synthesized with bipyridyl pillar ligands had lower basicity than DABCO however, they exhibited better stability in the presence of humid condition. 

CCP close-packed structures,or pillars are placed between the layers to provide the stabilization. We reported on compounds KMn02 i o,i84 (VO)j-Mn02, which are examples of such pillared structures. The former is stable to spinel formation at low current densities, and the latter shows excellent stability but poor rate capability. The groups of Dahn and Doeff among others have pursued non-ccp structures by looking at tunnel structures such as... 

Fast deactivation rates due to coking and the limited hydrothermal stability of pillared clays have probably retarded the commercial development of these new type of catalysts and prevented (to date) their acceptance by chemical producers and refiners. However, there is a large economic incentive justifying efforts to convert inexpensive (i.e. 40-100/ton) smectites into commercially viable (pillared clay) catalysts (56). Therefore, it is believed that work on the chemical modification of natural (and synthetic) clays, and work on the preparation and characterization of new pillared clays with improved hydrothermal stability are, and will remain, areas of interest to the academic community, as well as to researchers in industrial laboratories (56). 

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