Self-resonant Coil for Contactless Electrical Conductivity Measurement under Pulsed Ultra-high Magnetic Fields

In this study, we develop experimental apparatus for contactless electrical conductivity measurements under pulsed high magnetic fields over 100 T using a self-resonant-type high-frequency circuit. The resonant power spectra were numerically analyzed, and the conducted simulations showed that the apparatus is optimal for electrical conductivity measurements of materials with high electrical conductivity. The newly developed instruments were applied to a high-temperature cuprate superconductor La$_{2-x}$Sr$_x$CuO$_4$ to show conductivity changes in magnetic fields up to 102 T with a good signal-to-noise ratio. The upper critical field was determined with high accuracy.Comment: 11 pages, 5 figure

Fracture behavior of cracked full scale steel pipes used for gas and petroleum industries

The fracture toughness of pipeline steel grade X65 was investigated utilizing linear elastic fracture mechanics analysis, KIC testing according to non-standards techniques, as well as the elastic-plastic fracture mechanics analysis (J-Integral and crack opening displacement COD methods). The fracture toughness tests were conducted at full scale pipe used for gas and oil industry, circumferential surface crack were introduced to nine pipe specimens with different depths, crack/notch depths were selected to cover wide range of remaining material of the original pipe thickness, the original pipe thickness remain unchanged, a special fixture was manufactured to perform the experimental works, plane strain condition was confirmed by using plug insert inside the pipe specimen under the introduced circumferential surface crack. While for elastic-plastic fracture analysis a circumferential through-wall-cracked (TWC) pipes subjected to pure bending experiments were conducted on four pipe specimens, pipe thickness was reduced to 5 mm to meet the capacity of MTS machine used to perform the experimental works, in this analysis different parameters were measured. Tensile properties of the X65 steel as well as the chemical composition were measured and compared with that provided at inspection certificate and API standards, the results from experimental work were very close. Beside experimental work finite element method were used for analysis. Finite element modelling was used for comparison with experimental results. ABAQUS is used for FEM calculations for stresses distribution along the crack area, the simulation results were observed to have a good agreement with the experimental results

New Synthetic Strategies for Improved Gas separation by Nanoporous Organic Polymers

Abstract NEW SYNTHETIC STRATEGIES FOR IMPROVED GAS SEPARATION BY NANOPOROUS ORGANIC POLYMERS Suha S. Altarawneh, Ph.D. The emission of carbon dioxide (CO2) from fossil fuel combustion is a major cause of climate change. Therefore, the efficient separation of CO2 from mixtures of gases such as flue gas and impure sources of CH4 (e.g. natural gas and landfill gas) is an essential step in meeting the ever increasing demands on natural gas and creating a cleaner environment. Carbon capture and storage technology (CCS) is one of the methods employed for gas separation using chemisorption and/or physisorption processes. Several materials such as porous polymers and amine solutions have been used as gas adsorbents. However, the amount of energy required for the adsorbent regeneration is one of the main concerns that needs to be addressed. In this regard, porous organic polymers (POPs) with defined porosity and preferential binding affinity for CO2 over N2 and CH4 are some of the most attractive materials that could fulfill the above requirement and are also applicable for use in gas storage and separation. Suitable POPs that can be used for gas storage applications need to have high porosity and mechanical stability under high pressure conditions (~100 bar). Alternatively, the most effective POPs in gas separation are those that have preferential binding affinity for CO2 over other gases present at low pressure settings. In all cases, the chemical nature of POPs and their textural properties are key parameters, however, the modest surface area of most POPs limits their efficiency. With the above considerations in mind, the aim of our research is to develop benzimidazole–linked polymers (BILPs) that have variable porosity levels and chemical functionality to enhance gas separation (CO2/CH4, CO2/N2). We have established new synthetic routes that utilize polycondensation reactions between aryl-aldehydes and aryl-o-diamine building units to construct new BILPs with improved gas separation properties. Our strategy targeted structural and textural modifications of BILPs. We used longer linkers (building units) to improve porosity; however, the flexible linkers offered only low porosity due to network interpenetration. To overcome this challenge, a more controlled network growth rate was assessed by adjusting imine-bond formation rates through different acid loading. The acid, HCl, was used to catalyze imine-bond formation. The new resulting acid-catalyzed BILPs have shown an improved porosity up to 92% compared to the non-catalyzed BILPs. We also used the “rational ligand design” approach to introduce new functionalities into BILPs (-OR) to alter the hydrophobic nature of their pores. In this regard, we have illustrated the applicability of this strategy to BILPs containing flexible aryl-o-diamine linkers. The bulky alkoxy groups were incorporated into the aryl-aldehyde building unit prior to polymerization. The resulting polymers have proven that the presence of the bulky pendant alkoxy-chains plays a significant role during the polymerization process which allows for increased control over network formation, and in turn, porosity. Sorption measurements, selectivity, and heats of adsorption data have confirmed the positive impact of the alkoxy-groups and shown that varying the pendant groups is a promising method for designing highly porous BILPs. In addition to pore functionalization with alkoxy-chains, we used pi-conjugated and N-rich building units to prepare new BILPs that have semiconducting properties in addition to their porous nature. This class of BILPs has shown that the extended-conjugated system improved BILPs electronic properties. The other studies performed in this research, involved the use of DFT theory to investigate CO2/BILPs interaction sites and binding affinities. The computational outcomes of DFT have shown that (C-H) bond of the aryl system is a possible site for CO2 interaction beside the free-N side and hydrogen bonding. All new polymers were characterized by spectral and analytical characterization methods and their sorption data were collected to evaluate their capability as candidates for gas separation applications

Underlying trends in employment-output equation: the case of Jordan

The underlying employment trend (UET) is investigated in Jordanian economy over the period 1989- 2004 using structural time series model (STSM). This approach allows to modelling the trend in its stochastic form introduced by Harvey (1989). The results show that a stochastic trend is preferred to deterministic trend. In addition, the inclusion or exclusion of the conventional deterministic trend leads to overestimated output elasticity. Furthermore, the UET is found to be non-linear, down downward sloping.Employment, stochastic trend, structural time series modelling, Research and Development/Tech Change/Emerging Technologies, J20,

The Adoption of the National Programme for Information Technology in the UK National Health Service: The Case of Lorenzo

The failed National Programme for Information Technology (NPfIT) undertaken by the UK National Health Service (NHS) was described as the largest IT programme ever undertaken.  This paper considers the factors that influenced the implementation of one aspect of the NPfIT, Lorenzo, the Electronic Health Record system.Using grounded theory semi-structured interviews were conducted with respondents from the NHS and IT contractors to get a balanced approach on user acceptance from the client side and the supplier side.  NVIVO was used to aid the analysis of the interview data and the dominant categories which emerged, Clinicians’ Attributes, Organisational Factors and System Related Factors, are discussed.  The implications for IS academics and practitioners are outlined before the paper concludes. Keywords: Health Informatics, National Health Service, National Programme for Information Technology